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Sample records for black african black

  1. Overview of prostate cancer in indigenous black Africans and blacks of African ancestry in diaspora 1935-2007.

    Science.gov (United States)

    Magoha, G A O

    2007-09-01

    To carry out an overview of prostate cancer in indigenous back Africans in sub-Saharan Africa and blacks of African ancestry in diaspora. Review of all published literature on prostate cancer on indigenous black Africans and Africans in diaspora was carried out through medline and index medicus searches. Published data of prostate cancer in indigenous black Africans and black men in diaspora from 1935-2007 were included in the review. Abstracts of articles identified were assessed, read and analysed to determine their possible suitability and relevance to the title under review. After establishing relevance from the abstract, the entire paper was read, and the significant points included in the review. Prostate cancer incidence and magnitude in black Africans was grossly misunderstood and underestimated in the past. Prostate cancer incidence is on the increase and currently is perhaps the most common urological malignancy affecting black Africans. Its incidence and clinical characteristics is similar to that of the Africans in diaspora but different from all other races. There currently exists significant evidence which suggests a common enhancing genetic predisposition in black men to prostate cancer. There is very urgent need for further investigation of this phenomenon through randomised controlled multicentre studies involving indigenous black Africans and black men in diaspora.

  2. The Black Atlantic as reversal: A reappraisal of African and black theology

    Directory of Open Access Journals (Sweden)

    Hans Engdahl

    2017-09-01

    Full Text Available In this article, I will try to do three things. Firstly, pay attention to the notion of Black Atlantic as coined by Paul Gilroy, which in effect could signify a reversal of colonialism and slavery. Secondly, revisit the 1970s and the debate about the relevance of Black theology vis-à-vis African theology, using John Mbiti’s article ‘An African Views American Black Theology’ as entry point. Here, I will discuss contributions also made by Desmond Tutu and James Cone. Thirdly, starting with the premise that both theologies are relevant and soul mates today, which would (probably be confirmed by all the above mentioned at this point in time, an assessment of current voices will be made, that is, Tinyiko Maluleke and Vuyani Vellem on black and African ecclesiologies from a South African perspective, and Lawrence Burnley on the fate of the Black Church in the United States.

  3. Examining African self-consciousness and Black racial identity as predictors of Black men's psychological well-being.

    Science.gov (United States)

    Pierre, Martin R; Mahalik, James R

    2005-02-01

    This study investigated African self-consciousness and Black racial identity as predictors of psychological distress and self-esteem for Black men. One hundred thirty Black men from a college and community sample completed the African Self-Consciousness Scale, the Racial Identity Attitude Scale-B, the Symptom Checklist 90-Revised, and the Coopersmith Self-Esteem Inventory. Canonical correlation analysis found 2 significant roots with the 1st root indicating that Black men whose attitudes reflected Preencounter and Immersion racial identity attitudes and who do not resist against anti-African/Black forces reported greater psychological distress and less esteem. Results from the 2nd root suggested that Black men whose attitudes reflect greater Internalization racial identity attitudes, greater resistance to anti-African/Black forces, and less identification with Blacks reported greater self-esteem. ((c) 2005 APA, all rights reserved).

  4. Otosclerosis among South African indigenous blacks | Tshifularo ...

    African Journals Online (AJOL)

    Objective: To report cases of clinical otosclerosis histologically confirmed among indigenous South African blacks. Design: A retrospective study. Setting: Referral tertiary center, MEDUNSA, Garankuwa Hospital, South Africa. Subjects: All fifteen indigenous South African blacks diagnosed with clinical otosclerosis at ...

  5. Breeding phenology of African Black Oystercatchers Haematopus ...

    African Journals Online (AJOL)

    The timing of the start and duration of breeding and the effect of these on breeding productivity were analysed for African Black Oystercatchers Haematopus moquini on Robben Island, South Africa, over three breeding seasons from 2001 to 2004. African Black Oystercatchers have a long breeding season, from November ...

  6. Job-hopping amongst African Black senior management in South Africa

    Directory of Open Access Journals (Sweden)

    Khanyile C.C. Nzukuma

    2011-11-01

    Research purpose: The study focused on understanding why African Black senior managers have a propensity to change jobs and how organisations can resolve the trend. Motivation for the study: To develop a better understanding of the push and pull factors for African Black senior managers in organisations. Research design, approach and method: The research was conducted in two phases, namely as part of a qualitative study and a quantitative study: Creswell (2003 refers to this approach as triangulation. The target population was African Black senior managers on the database of a large Human Resources Consultancy, The South African Rewards Association and the Association of Black Actuaries and Investment Professionals (ABSIP (n = 2600. A total of 208 usable responses were received. Main findings: The main findings and contribution to the field of study was that African Black senior managers do not trust organisations with their career development. They would rather take control of their own career development by moving from organisation to organisation to build their repertoire of skills and competence. They want to be in charge of their careers. This finding has profound implications for organisations employing African Black managers in the senior cadre. Practical/managerial implications: Managers of African Black senior managers need to create attractive employee value propositions that address the main findings. Contribution/value-add: The research shows that African Black senior managers generally seek corporate environments that encourage a sense of belonging and with a clear career growth plan.

  7. Internalized racism and mental health among African-Americans, US-born Caribbean Blacks, and foreign-born Caribbean Blacks.

    Science.gov (United States)

    Mouzon, Dawne M; McLean, Jamila S

    2017-02-01

    The tripartite model of racism includes personally mediated racism, institutionalized racism, and the less-oft studied internalized racism. Internalized racism - or negative beliefs about one's racial group - results from cultural racism that is endemic in American society. In this project, we studied whether these negative stereotypes are associated with mental health among African-Americans and Caribbean Blacks. Using secondary data from the National Survey of American Life, we investigated the association between internalized racism and mental health (measured by depressive symptoms and serious psychological distress (SPD)) among these two groups. We also explored whether ethnicity/nativity and mastery moderate the association between internalized racism and mental health among African-Americans and Caribbean Blacks. Internalized racism was positively associated with depressive symptoms and SPD among all Black subgroups. However, internalized racism was a weaker predictor of SPD among foreign-born Caribbean Blacks than US-born Caribbean Blacks and US-born African-Americans. Additionally, higher mastery was protective against distress associated with internalized racism. Internalized racism is an important yet understudied determinant of mental health among Blacks. Future studies should take into account additional heterogeneity within the Black population (e.g. African-born individuals) and other potential protective mechanisms in addition to mastery (e.g. self-esteem and racial identity).

  8. Theorizing black (African) transnational masculinities

    OpenAIRE

    Pasura, Dominic; Christou, Anastasia

    2017-01-01

    Just as masculinity is crucial in the construction of nationhood, masculinity is also significant in the making and unmaking of transnational communities. This article focuses on how black African men negotiate and perform respectable masculinity in transnational settings, such as the workplace, community, and family. Moving away from conceptualizations of black transnational forms of masculinities as in perpetual crisis and drawing on qualitative data collected from the members of the new Af...

  9. Post-apartheid transnationalism in black South African literature: A ...

    African Journals Online (AJOL)

    The quest of this paper is to probe whether globalising post-nationalism impacts on post- apartheid black South African English literature in a manner that suggests a blurring of distinctive African identities. This is done against the background that black South African literature right from its written beginnings in the early 19th ...

  10. The Self-Concept Level of Black Adolescents with and without African Names.

    Science.gov (United States)

    Terrell, Francis; And Others

    1988-01-01

    Explored the self-concept level of Black adolescents with and without African names, and of their parents, using the Terrell and Taylor Black Ideology Scale and the Coopersmith Self-Esteem Inventory. Adolescents with African names demonstrated significantly higher scores on the Black self-concept scales than did those without African names.…

  11. Barriers to early diagnosis of symptomatic breast cancer: a qualitative study of Black African, Black Caribbean and White British women living in the UK

    Science.gov (United States)

    Jones, Claire E L; Maben, Jill; Lucas, Grace; Davies, Elizabeth A; Jack, Ruth H; Ream, Emma

    2015-01-01

    Objectives Understanding barriers to early diagnosis of symptomatic breast cancer among Black African, Black Caribbean and White British women in the UK. Design In-depth qualitative interviews using grounded theory methods to identify themes. Findings validated through focus groups. Participants 94 women aged 33–91 years; 20 Black African, 20 Black Caribbean and 20 White British women diagnosed with symptomatic breast cancer were interviewed. Fourteen Black African and 20 Black Caribbean women with (n=19) and without (n=15) breast cancer participated in six focus groups. Setting Eight cancer centres/hospital trusts in London (n=5), Somerset (n=1), West Midlands (n=1) and Greater Manchester (n=1) during 2012–2013. Results There are important differences and similarities in barriers to early diagnosis of breast cancer between Black African, Black Caribbean and White British women in the UK. Differences were influenced by country of birth, time spent in UK and age. First generation Black African women experienced most barriers and longest delays. Second generation Black Caribbean and White British women were similar and experienced fewest barriers. Absence of pain was a barrier for Black African and Black Caribbean women. Older White British women (≥70 years) and first generation Black African and Black Caribbean women shared conservative attitudes and taboos about breast awareness. All women viewed themselves at low risk of the disease, and voiced uncertainty over breast awareness and appraising non-lump symptoms. Focus group findings validated and expanded themes identified in interviews. Conclusions Findings challenged reporting of Black women homogenously in breast cancer research. This can mask distinctions within and between ethnic groups. Current media and health promotion messages need reframing to promote early presentation with breast symptoms. Working with communities and developing culturally appropriate materials may lessen taboos and stigma

  12. Barriers to early diagnosis of symptomatic breast cancer: a qualitative study of Black African, Black Caribbean and White British women living in the UK.

    Science.gov (United States)

    Jones, Claire E L; Maben, Jill; Lucas, Grace; Davies, Elizabeth A; Jack, Ruth H; Ream, Emma

    2015-03-13

    Understanding barriers to early diagnosis of symptomatic breast cancer among Black African, Black Caribbean and White British women in the UK. In-depth qualitative interviews using grounded theory methods to identify themes. Findings validated through focus groups. 94 women aged 33-91 years; 20 Black African, 20 Black Caribbean and 20 White British women diagnosed with symptomatic breast cancer were interviewed. Fourteen Black African and 20 Black Caribbean women with (n=19) and without (n=15) breast cancer participated in six focus groups. Eight cancer centres/hospital trusts in London (n=5), Somerset (n=1), West Midlands (n=1) and Greater Manchester (n=1) during 2012-2013. There are important differences and similarities in barriers to early diagnosis of breast cancer between Black African, Black Caribbean and White British women in the UK. Differences were influenced by country of birth, time spent in UK and age. First generation Black African women experienced most barriers and longest delays. Second generation Black Caribbean and White British women were similar and experienced fewest barriers. Absence of pain was a barrier for Black African and Black Caribbean women. Older White British women (≥70 years) and first generation Black African and Black Caribbean women shared conservative attitudes and taboos about breast awareness. All women viewed themselves at low risk of the disease, and voiced uncertainty over breast awareness and appraising non-lump symptoms. Focus group findings validated and expanded themes identified in interviews. Findings challenged reporting of Black women homogenously in breast cancer research. This can mask distinctions within and between ethnic groups. Current media and health promotion messages need reframing to promote early presentation with breast symptoms. Working with communities and developing culturally appropriate materials may lessen taboos and stigma, raise awareness, increase discussion of breast cancer and promote

  13. Black Air: African American Contributions to Airpower before Integration

    Science.gov (United States)

    2010-06-01

    Bullard Black Expatriate in Jazz -Age Paris, 151. 13 of influential white Americans that no Black man could ever do, and that was to fly. Flight was a... BLACK AIR: AFRICAN AMERICAN CONTRIBUTIONS TO AIRPOWER BEFORE INTEGRATION BY MAJOR DAMONE GARNER A THESIS PRESENTED TO THE FACULTY OF THE...contributions to the overall victory. When Black Americans went into combat on the beaches of Normandy, in the hills of Italy, and in the jungles of the

  14. The Crisis in Black and Black.

    Science.gov (United States)

    Hutchinson, Earl Ofari

    These essays explore why the historic conflict between blacks and whites in the United States has become a crisis that divides many African Americans. The changing racial dynamic is not marked by conflicts. between the black middle class and the poor, black men and women, the black intellectual elite and rappers, black politicians and the urban…

  15. African American film sound: scoring blackness

    OpenAIRE

    Doughty, Ruth

    2008-01-01

    The term ‘black music’ has long been a cause for contention. What do we mean by music being ‘black’, or more specifically in the case of this chapter, African American? The music industry has typically marketed products via the categorization of specific genres: for example, jazz, blues, soul, funk and rap. These generic types are often classified as ‘black music’. Philip Tagg vehemently debates the suitability of such an essentializing label, as he correctly argues that aesthetic practice is...

  16. The Canonical Black Body: Alternative African American Religions and the Disruptive Politics of Sacrality

    Directory of Open Access Journals (Sweden)

    Joseph L. Tucker Edmonds

    2018-01-01

    Full Text Available “The Canonical Black Body” argues that central to the study of African American religions is a focus on the black body and the production and engagement of canons on the sacred black body within the black public sphere. Furthermore, this essay suggests that, by paying attention to alternative African American religions in the twentieth century, we can better engage the relationship between African American religion and the long history of creating these canons on the black body, debating their relationship to black freedom, and circulating the canons to contest the oppressive, exclusive practices of modern democracy. Through a critical engagement of the fields of Black Theology and New Religious Movements and using the resources offered by Delores Williams’ accounts of variety and experience and Vincent Wimbush’s category of signifying, this essay will argue for how a return to the body provides resources and tools for not only theorizing African American religions but thinking about the production and creation of competing black publics, including the important role of alternative black sacred publics.

  17. High risk of metabolic syndrome among black South African women ...

    African Journals Online (AJOL)

    Background: There is an increased prevalence of metabolic syndrome (MetS) in individuals with severe mental illness (SMI) globally. The prevalence of MetS is higher in black women compared to black men from South Africa. Aim: To compare the prevalence of MetS between black South African men and women with SMI ...

  18. Black African Immigrant College Students' Perceptions of Belonging at a Predominately White Institution

    Science.gov (United States)

    Stebleton, Michael J.; Aleixo, Marina B.

    2016-01-01

    A growing number of college-age Blacks in the United States are Black African immigrants. Using a constructivist grounded theory approach, the researchers interviewed 12 undergraduate Black African immigrant college students attending a predominately White institution (PWI) about their experiences and perceptions of belonging. Findings suggest…

  19. Barriers to HIV testing for migrant black Africans in Western Europe.

    Science.gov (United States)

    Fakoya, I; Reynolds, R; Caswell, G; Shiripinda, I

    2008-07-01

    Migrant black Africans are disproportionately affected by HIV in Western Europe; we discuss the barriers to HIV testing for sub-Saharan migrants, with particular emphasis on the UK and the Netherlands. Cultural, social and structural barriers to testing, such as access to testing and care, fear of death and disease and fear of stigma and discrimination in the community, can be identified. Lack of political will, restrictive immigration policies and the absence of African representation in decision-making processes are also major factors preventing black Africans from testing. HIV testing strategies need to be grounded in outreach and community mobilisation, addressing fear of diagnosis, highlighting the success of treatment and tackling HIV-related stigma among black African migrant communities.

  20. Eating disorders in black South African females | Szabo | South ...

    African Journals Online (AJOL)

    Eating disorders are generally associated with westernised white populations. Isolated cases of anorexia nervosa have been described in blacks in Africa. A series of cases is presented documenting the existence of eating disorders in young black South African women. This has implications in terms of both conceptualising ...

  1. A study to evaluate the performance of black South African urban ...

    African Journals Online (AJOL)

    Background. A suitable tool is needed to assess child development in South Africa (SA). Using Western normed tools presents difficulties. Aim. To determine whether the Bayley Scales of Infant Development III (Bayley-III) can be used on black African urban infants in SA. Method. One hundred and twenty-two black African ...

  2. "Black Like Me": Reframing Blackness for Decolonial Politics

    Science.gov (United States)

    Dei, George J. Sefa

    2018-01-01

    From a particular vantage point, as an African-born scholar with a politics to affirm my Black subjectivity and Indigeneity in a diasporic context, my article engages a (re)theorization of Blackness for decolonial politics. Building on existing works of how Black scholars, themselves, have theorized Blackness, and recognizing the fluid,…

  3. Why Not Academia?--The Streamlined Career Choice Process of Black African Women Engineers: A Grounded Theory Study

    Science.gov (United States)

    Mlambo, Yeukai Angela

    2017-01-01

    Black African women are grossly underrepresented as academic staff in engineering programs at South African universities. The problem is exacerbated at historically White institutions (HWI) where Black women are simply absent as engineering research and teaching staff. The absence of Black African women in the academy occurs despite Black African…

  4. Clinical and radiological features of rheumatoid arthritis in British black Africans.

    Science.gov (United States)

    Ravindran, Vinod; Seah, May-Ai; Elias, David A; Choy, Ernest H; Scott, David L; Gordon, Patrick A

    2008-01-01

    The objective of this study was to determine whether radiographic damage is different in British black African patients with rheumatoid arthritis compared to Caucasian patients. Data on demographics, disease- and disability-related variables were obtained from all black African patients and their age-, gender- and disease-duration-matched Caucasian controls. After all features identifying the patients were concealed, X-rays of hands and feet were scored by using the Sharp/van der Heijde method. Data were analysed using Mann-Whitney U test, t test and chi (2) test. Sixty-four patients (32 in each ethnic group) were studied. The median age was 52 years and median disease duration 6 years. Seventy-two percent of patients were female. Black Africans and Caucasians did not differ significantly in rheumatoid factor positivity, disease-modifying anti-rheumatic drugs and biological treatment use. British black African patients had significantly more tender joints and disability. Joint space narrowing was significantly greater in Caucasian patients [48 (27-85) vs 56 (34-107), p = 0.01]. Caucasian patients had more number of erosions (172 vs 220) and higher erosion score; however, the difference in the erosion scores was not statistically significant [2 (0-48) vs 4.5 (0-46), p = 0.17]. Radiographic damage was less severe in black African patients with rheumatoid arthritis compared to their age-, gender- and disease-duration-matched Caucasian controls. A large prospective study is required to confirm the findings of this study and to establish the factors which might be accountable for any differences in the expression of rheumatoid arthritis in this ethnic group.

  5. Phaeochromocytoma in black South Africans – a 30-year audit ...

    African Journals Online (AJOL)

    tumours, the majority of which arise from the adrenal medulla. Untreated, they are potentially lethal; early diagnosis and treatment offer a good chance of cure. They are rarely reported in blacks. The clinical presentation and outcome of phaeochromocytoma in a large cohort of black South Africans is reviewed. Methods.

  6. South African black generation Y students' perceptions of local black celebrity endorsers' credibility / Boitumelo Vincent Molelekeng

    OpenAIRE

    Molelekeng, Boitumelo Vincent

    2012-01-01

    The use of celebrity endorsers is a popular marketing strategy in many countries. Typically, many marketers believe that using celebrities is a viable marketing strategy for attracting customers, increasing market share and improving sales for their market offerings. The celebrity endorsement strategy using local celebrities is increasing in South Africa. Many South African marketers are now using popular local black celebrities in an attempt to attract the prosperous black emerging middle cl...

  7. Influences and Retentions of West African Musical Concepts in U.S. Black Music.

    Science.gov (United States)

    Maultsby, Portia K.

    1979-01-01

    Current research reveals that West African musical concepts provided the foundation for the various musical genres created by Black Americans. The Black musical tradition continues to evolve and mirror new values, attitudes, philosophies, and life-styles without the loss of a West African identity. (RLV)

  8. #BlackBabiesMatter: Analyzing Black Religious Media in Conservative and Progressive Evangelical Communities

    Directory of Open Access Journals (Sweden)

    Monique Moultrie

    2017-11-01

    Full Text Available This article explores how conservative and progressive black Protestants interrogate the theological theme of the sacrality of black life through digital media. The innovations of religious media in black evangelical communities remain an understudied phenomenon in African American religion, making this an apt arena for further discovery. This current intervention into the study of African American Religion examines digital activism through examples of religious media produced by blacks for black audiences. This article begins its interrogation of the sacrality of black life by juxtaposing those who contend that Black Babies Matter as pro-birth-oriented, religiously motivated activists with those religious opponents asserting Black Lives Matter who present an intersectional pro-life approach. The comparison of views relies on womanist cultural analysis as its main methodology to analyze and interpret digital media and explore its ramifications for African American Religion.

  9. Maternity and paternity leave and career progression of black African women in dual-career couples

    Directory of Open Access Journals (Sweden)

    Lucky L. Motaung

    2017-09-01

    Full Text Available Orientation: The study focused on examining the perceptions of dual-career couples at a stateowned company about the influence of taking maternity and paternity leave on the career progression of black African women in middle management and leadership occupations. Research purpose: The primary purpose of the study was to identify core barriers in relation to maternity and paternity leave that contribute negatively in the career progression of black African women in dual-career couples. Motivation for the study: To obtain insight into the underrepresentation and progression of black African women within dual-career couples, in middle management and leadership occupations. Research design, approach and method: This study was qualitative, comprising a sample of 10 black African women and 10 black African men, with data collected through in-depth semistructured interviews. Thematic analysis was utilised to analyse the interview dialogues. Main findings: The findings established that taking maternity leave has a negative influence on the career progression of black African women in dual-career couples at the state-owned company. The participants further confirmed that involuntary time off work and productiveness were principal influencing barriers of taking maternity leave, leading to other undesirable consequences, such as unproductiveness and reliability. Practical and managerial implications: The state-owned company should review its current talent management and recruitment and selection policies, in order to positively contribute to increasing the representation and facilitating career progression of black African women within dual-career couples, in middle management and leadership occupations. Contributions or value-add: Insights were provided on the influences of taking maternity and paternity leave in the underrepresentation and progression of black African women within dual-career couples, in middle management and leadership occupations.

  10. Rules of engagement: predictors of Black Caribbean immigrants' engagement with African American culture.

    Science.gov (United States)

    Joseph, Nancy; Watson, Natalie N; Wang, Zhenni; Case, Andrew D; Hunter, Carla D

    2013-10-01

    The cultural context in the United States is racialized and influences Black Caribbean immigrants' acculturation processes, but what role it plays in Black Caribbean immigrants' acculturation into specific facets of American society (e.g., African American culture) has been understudied in the field of psychology. The present study extends research on Black Caribbean immigrants' acculturative process by assessing how this group's experience of the racial context (racial public regard, ethnic public regard, and cultural race-related stress) influences its engagement in African American culture (i.e., adoption of values and behavioral involvement). Data were collected from 93 Black participants of Caribbean descent, ranging in age from 13 to 45 and analyzed using a stepwise hierarchical regression. The findings highlighted that when Black Caribbean-descended participants perceived that the public held a favorable view of their racial group they were more likely to engage in African American culture. In contrast, when participants perceived that the public held a favorable view of their ethnic group (e.g., Haitian) they were less likely to engage in African American culture. Furthermore, among participants experiencing low levels of cultural race-related stress, the associations between racial public regard and engagement with African American culture were amplified. However, for participants experiencing high cultural race-related stress, their engagement in African American culture did not change as a function of racial public regard. These findings may suggest that, for Black Caribbean immigrants, the experience of the racial context influences strategies that serve to preserve or bolster their overall social status and psychological well-being in the United States. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  11. The relationships among Black consciousness, self-esteem, and academic self-efficacy in African American men.

    Science.gov (United States)

    Okech, Allan Prince; Harrington, Rick

    2002-03-01

    The purpose of this study was to investigate the relationships among Black consciousness, self-esteem, and academic self-efficacy in African American men. The participants were 120 African American male college students at a predominantly African American university. The authors administered 3 instruments--the Developmental Inventory of Black Consciousness (DIB-C; J. Milliones, 1980), the M. Rosenberg (1965) Self-Esteem Scale, and R. E. Wood and E. A. Locke's (1987) Academic Self-Efficacy Scale--to test the hypotheses. They used an independent-measures t test and a Pearson r correlation to analyze the data. The results of the study supported the hypotheses under investigation. Significant positive relationships were found between Black consciousness and self-esteem and Black consciousness and academic self-efficacy. The results of the study showed that Black consciousness appears to be an important construct to use in understanding self-esteem and academic self-efficacy in African American men.

  12. The housing careers of black middle-class residents in a South African metropolitan area

    CSIR Research Space (South Africa)

    Marais, L

    2018-01-01

    Full Text Available Africans was restored in the mid-1980s and the Group Areas Act was repealed in 1991. Democracy opened up economic opportunities previously unavailable to black people. This paper investigates the effect on black middle-class South African households...

  13. Tooth width predictions in a sample of Black South Africans.

    Science.gov (United States)

    Khan, M I; Seedat, A K; Hlongwa, P

    2007-07-01

    Space analysis during the mixed dentition requires prediction of the mesiodistal widths of the unerupted permanent canines and premolars and prediction tables and equations may be used for this purpose. The Tanaka and Johnston prediction equations, which were derived from a North American White sample, is one example which is widely used. This prediction equation may be inapplicable to other race groups due to racial tooth size variability. Therefore the purpose of this study was to derive prediction equations that would be applicable to Black South African subjects. One hundred and ten pre-treatment study casts of Black South African subjects were analysed from the Department of Orthodontics' records at the University of Limpopo. The sample was equally divided by gender with all subjects having Class I molar relationship and relatively well aligned teeth. The mesiodistal widths of the maxillary and mandibular canines and premolars were measured with a digital vernier calliper and compared with the measurements predicted with the Tanaka and Johnston equations. The relationship between the measured and predicted values were analysed by correlation and regression analyses. The results indicated that the Tanaka and Johnston prediction equations were not fully applicable to the Black South African sample. The equations tended to underpredict the male sample, while slight overprediction was observed in the female sample. Therefore, new equations were formulated and proposed that would be accurate for Black subjects.

  14. Systematic review of stigma reducing interventions for African/Black diasporic women.

    Science.gov (United States)

    Loutfy, Mona; Tharao, Wangari; Logie, Carmen; Aden, Muna A; Chambers, Lori A; Wu, Wei; Abdelmaseh, Marym; Calzavara, Liviana

    2015-01-01

    Literature indicates that racism, sexism, homophobia and HIV-related stigma have adverse impacts on health, well-being, and quality of life among HIV-positive women of African descent (African/Black diaspora). However, limited evidence exists on the effectiveness of interventions aimed at reducing stigma tailored for these women. This study systematically reviewed randomized controlled trials (RCTs), non-randomized observational and quasi-experimental studies evaluating the effectiveness of interventions aimed at reducing stigma experienced by this population. The Cochrane methodology was used to develop a search strategy in consultation with a librarian scientist. Databases searched included the Cochrane Library, Ovid EMBASE, PsycInfo, and 10 others. Two reviewers independently assessed the studies for potential relevance and conducted the Cochrane grading of RCTs to assess risk of bias and the Newcastle-Ottawa scale to assess the quality of non-randomized studies. Eligible papers were selected if they employed an intervention design with African/Black diasporic women living with HIV as the target population and had a primary outcome of stigma reduction. Of the five studies that met all of the eligibility criteria, four demonstrated the effectiveness of interventions in reducing HIV-related stigma. Only two of the five studies were designed specifically for HIV-positive African/Black diasporic women. Limitations included the absence of interventions addressing other forms of stigma and discrimination (e.g. gender discrimination, racism, heterosexism). Our findings suggest that there are limited interventions designed to address multiple forms of stigma, including gender and racial discrimination, experienced by HIV-positive African/Black diasporic women.

  15. Black Americans, Africa and History: A Reassessment of the Pan-African and Identity Paradigms.

    Science.gov (United States)

    Adeleke, Tunde

    1998-01-01

    Examines the paradigm of Pan-Africanism and the identity construct in the historic and cultural contexts of blacks outside of Africa, critiquing theories on the African identity construct. Suggests that black American identity is too complex for this simplification and must be considered within the context of world acculturation. Contains 34…

  16. Tobacco smoking in black and white South Africans | Peltzer | East ...

    African Journals Online (AJOL)

    Tobacco smoking in black and white South Africans. K. Peltzer. Abstract. (East African Medical Journal: 2001 78(3): 115-118). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/eamj.v78i3.9074 · AJOL African Journals Online.

  17. Physical activity energy expenditure and sarcopenia in black South African urban women

    NARCIS (Netherlands)

    Kruger, Herculina S.; Havemann-Nel, Lize; Ravyse, Chrisna; Moss, Sarah J.; Tieland, Michael

    2016-01-01

    Background: Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. Methods: In a cross-sectional study, 247 women (mean age 57 y)

  18. Book review: Femi Abodunrin, Black African Literature in English ...

    African Journals Online (AJOL)

    Book review: Femi Abodunrin, Black African Literature in English 1991-2001: Critical Appreciation and Reception; Mkuki na Nyota Publishers, Dar es Salaam, 2007, 236 pp. ISBN 9987449182/ISBN 13:978-9987-449-18-7.

  19. Black American and Nigerian Pentecostalism: A Black Religious ...

    African Journals Online (AJOL)

    Black American and Nigerian Pentecostalism: A Black Religious Schizophrenia, 1910-2010. ... in American and African Pentecostalism as is related to social crisis, the dislocation of masses brought on by economic deprivation, urbanization, the break up of traditional society and consequence loss of traditional values.

  20. Proliferaton index in pituitary adenomas from a black African ...

    African Journals Online (AJOL)

    Ayodeji Salami

    2016-12-31

    Dec 31, 2016 ... tumours show invasion of surrounding structures with increase in proliferation.4 The ... of pituitary adenomas in the black African population. This is a pre- ... ized and diluted (1:200) KI67 rabbit primary antibody. (Thermofisher ...

  1. High risk of metabolic syndrome among black South African women with severe mental illness

    Directory of Open Access Journals (Sweden)

    Shamima Saloojee

    2017-04-01

    Full Text Available Background: There is an increased prevalence of metabolic syndrome (MetS in individuals with severe mental illness (SMI globally. The prevalence of MetS is higher in black women compared to black men from South Africa. Aim: To compare the prevalence of MetS between black South African men and women with SMI taking antipsychotic medication. Further, this prevalence was compared to the prevalence in a matched control group of black South African men and women without SMI. Setting: A general hospital psychiatric unit. Methods: A cross-sectional study was undertaken to compare the prevalence of MetS in a group of multi-ethnic participants with SMI treated with antipsychotic medication and a matched control group without SMI, applying the 2009 Joint Interim Statement (JIS criteria. Here, we included only the black African participants to compare MetS prevalence between men and women. Results: There were 232 participants in the group with SMI (male 155 and female 77 and without SMI (male 156 and female 76. The prevalence of MetS was more than three times higher in women with SMI compared to men with SMI (37.7% vs. 10.3%, p < 0.001. There was no significant difference in the prevalence of MetS in men or women between the groups with and without SMI. In multivariate logistic regression analysis, female gender (odds ratio [OR] 7.66, advancing age (OR 1.08 and longer duration of illness (OR = 1.15 were significant risk factors for MetS in SMI. Conclusion: In black South Africans with SMI on antipsychotic medication, there is a higher prevalence and risk for MetS in women compared to men.

  2. Layers of Blackness: Colourism in the African Diaspora

    OpenAIRE

    Gabriel, Deborah

    2007-01-01

    This is the first book by an author in the UK to take an in-depth look at colourism - the process of discrimination based on skin tone among members of the same ethnic group, whereby lighter skin is more valued than darker complexions. The African Diaspora in Britain is examined as part of a global black community with shared experiences of slavery, colonization and neo-colonialism. The author traces the evolution of colourism within African descendant communities in the USA, Jamaica, Latin A...

  3. The Black Family as Educator.

    Science.gov (United States)

    Wallace, Joan

    The black family is the primary socializing agent of the black child and, thus, the primary educator. The culture of blacks in America, in which the child is steeped, is unique, complex and rich-the result of a convergence and fusion of African, American, and European influences. In its education of the black child, the black family must deal,…

  4. Global Norms and local requirements for Black South African ...

    African Journals Online (AJOL)

    Global Norms and local requirements for Black South African English ('BSAE')? -- A pilot study of teachers' assessment and perceptions of learner texts ... reports on the pilot study of a still-ongoing research project which investigates teachers' language perceptions and language use in mainly BSAE-using classrooms.

  5. a photoreceptor gene mutation in an indigenous black african family

    African Journals Online (AJOL)

    MUTATION IN AN INDIGENOUS. BLACK AFRICAN FAMILY WITH. RETINITIS PIGMENTOSA. IDENTIFIED USING A RAPID. SCREENING APPROACH FOR. COMMON RHODOPSIN. MUTATIONS. JGreenberg, T Franz, R Goliath, R Ramesar. Hereditary retinal degenerations may be subdivided into those affecting ...

  6. Overweight and Physical Inactivity Among African American Students at a Historically Black University.

    Science.gov (United States)

    Sa, Jaesin; Heimdal, James; Sbrocco, Tracy; Seo, Dong-Chul; Nelson, Beatrice

    2016-02-01

    Little is known about correlates of overweight, obesity, and physical inactivity among African American students at historically Black colleges and universities. To assess overweight, obesity, and physical inactivity among African American college students at a historically Black university in Maryland in the USA. Data were collected from 268 African American college students in 2013. Data were analyzed with percentage difference z-tests, chi-square tests, and multiple logistic regression. Cross-sectional survey (student response rate = 49.9%). The overweight/obesity rate of participants was 47.5%, which was higher than that of the U.S. college student population overall (34.1%) and a representative sample of African American college students (38.3%). When age and sex were controlled, a family history of obesity, skipping breakfast, drinking caffeinated drinks, lower family income, and smoking a pipe, cigars, or cigarettes daily were significant correlates of overweight (obesity included). The percentage of physical inactivity was 68.3, and physical inactivity was higher among women and overweight or obese students. Given the high overweight and obesity prevalence among African American college students, historically Black colleges and universities in the USA should increase health promotion efforts targeting weight-related behaviors, particularly physical activity. Copyright © 2016. Published by Elsevier Inc.

  7. Use of professional and informal support by African Americans and Caribbean blacks with mental disorders.

    Science.gov (United States)

    Woodward, Amanda Toler; Taylor, Robert Joseph; Bullard, Kai McKeever; Neighbors, Harold W; Chatters, Linda M; Jackson, James S

    2008-11-01

    This study investigated the use of professional services and informal support among African Americans and Caribbean blacks with a lifetime mood, anxiety, or substance use disorder. Data were from the National Survey of American Life. Multinomial logistic regression was used to test the utilization of professional services only, informal support only, both, or neither. Analyses controlled for sociodemographic characteristics, disorder-related variables, and family network variables. The analytic sample included 1,096 African Americans and 372 Caribbean blacks. Forty-one percent used both professional services and informal support, 14% relied on professional services only, 23% used informal support only, and 22% did not seek help. There were no significant differences in help seeking between African Americans and Caribbean blacks. Having co-occurring mental and substance use disorders, having a severe disorder in the past 12 months, having more people in the informal helper network, and being female increased the likelihood of using professional services and informal supports. When men sought help, they were more likely to rely on informal helpers. Marital status, age, and socioeconomic status were also significantly related to help seeking. The significant proportion of black Americans with a mental disorder who relied on informal support alone, professional services alone, or no help at all suggests potential unmet need in this group. However, the reliance on informal support also may be evidence of a strong protective role that informal networks play in the lives of African Americans and Caribbean blacks.

  8. Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

    Directory of Open Access Journals (Sweden)

    Zelda de Lange

    Full Text Available Studies in populations of European descent show longer plasma clot lysis times (CLT in patients with cardiovascular disease (CVD than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years were cross-sectionally analysed.Increased PAI-1(act, BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

  9. Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

    Science.gov (United States)

    de Lange, Zelda; Pieters, Marlien; Jerling, Johann C; Kruger, Annamarie; Rijken, Dingeman C

    2012-01-01

    Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years) were cross-sectionally analysed.Increased PAI-1(act), BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

  10. The Black Consciousness Movement in South Africa: A Product of The Entire Black World

    Directory of Open Access Journals (Sweden)

    Mgwebi Snail

    2009-12-01

    Full Text Available El trabajo ilustra cómo el surgimiento del Movimiento de Conciencia Negra en Sudáfrica puede estar diametralmente unido a la emergencia de los movimientos de Conciencia Negra y Black Power en América. Pretende demostrar además cómo, en el contexto africano, el Movimiento de Conciencia Negra fue impulsado por el nacionalismo africano y cómo ese nacionalismo fue moldeado y transformado por pensadores africanos de la década de los 50 y 60 en el Panafricanismo. El artículo también mostrará similitudes y diferencias entre la Negritud Africana y el Movimiento de Conciencia Negra. El texto de nuevo explicará de manera cronológica cómo el Garveyismo, la Conciencia Negra en América y el nacionalismo africano, la personalidad africana y la Negritud en África contribuyeron al surgimiento del Movimiento de Conciencia Negra en Sudáfrica. El estudio advierte de que la falta de comprensión de estos antecedentes, podría llevar a la confusión y a una mala interpretación de concepto vital en la historia de África. Finalmente, este trabajo busca hacer hincapié en la historización del desarrollo del por qué el Movimiento de Conciencia Negra en Sudáfrica no puede estar divorciado del contexto global.____________________ABSTRACT:The paper illustrates how the rise of the Black Consciousness Movement in South Africa can be diametrically tied up with the emergence of the Black Consciousness and Black-Power Movements in America. It goes further to demonstrate how, in the African context, the Black Consciousness Movement was given impetus by African nationalism and how that nationalism was later moulded and shaped by African thinkers of the 1950’s and 1960’s into Pan Africanism. The paper, will also try to show similarities and the disparities between Negritude African personality and the Black Consciousness Movement. The paper will again explain in a chronological manner how Garveyism, Black Consciousness in America and African Nationalism in

  11. Stigma, lack of knowledge and prevalence maintain HIV risk among Black Africans in New Zealand.

    Science.gov (United States)

    Henrickson, Mark; Dickson, Nigel; Mhlanga, Fungai; Ludlam, Adrian

    2015-02-01

    The AfricaNZ Health project aimed explore HIV risks in Black African communities in NZ with a view to informing HIV infection prevention and health promotion programs. AfricaNZ Health was completed in two phases. The first developed desk estimates of the resident Black African population in New Zealand, and Africans living with HIV. The second comprised two arms: an anonymous survey administered at African community events and a series of focus groups around the country. High levels of knowledge and positive attitudes about HIV were more often found in older than younger age groups. Condom use was higher in the younger group than in older age groups. Traditional attitudes still inform some beliefs about HIV. Stigma about HIV and anyone at risk for HIV remains very high among Africans. Western sexual identity constructs are not meaningful. A culturally informed strategy for risk and stigma reduction is urgently needed. The existing prevention and care infrastructure, informed by MSM experiences, must address increased risk to Black African new settlers, but this is not a reason to discriminate or further stigmatise an already vulnerable population. © 2014 Public Health Association of Australia.

  12. Unpacking the downside of sustentasie on African theology and theologians: a need for contextual black theology as a liberative ingredient for the black Reformed churches

    Directory of Open Access Journals (Sweden)

    Elijah Baloyi

    2016-08-01

    Full Text Available The practice of the black church being a follower of the leading white church is a continuous process in the Gereformeerde Kerke in Suid Afrika (or Reformed Churches in South Africa in English. This makes it difficult to contextualise Reformed Theology to address African challenges and problems. There are many reasons for the subordination of the black theologians, but for the sake of this article, I identified the issue of sustentasie1 as one of the causes. The lack of financial independence implies that the black church2 cannot determine their destiny by revising, transforming and even Africanising their theology to fit into their context and challenges, since that would mean they are biting the hand that feeds them. This article will argue that it is time that Africans stop being a theological duplication of the Western theologies and that they take responsibility to ensure that their theology addresses the immediate situation of the Black Reformed people (contextualised with or without the support from the white church.

  13. 'Just talking about it opens your heart': meaning-making among Black African migrants and refugees living with HIV.

    Science.gov (United States)

    Henrickson, Mark; Brown, Derek Brian; Fouché, Christa; Poindexter, Cynthia C; Scott, Kay

    2013-01-01

    Meaning-making has emerged as a core construct in addressing trauma, loss or crisis. This paper considers how diasporic Black Africans living with HIV, who come from interdependent collectivist cultures where the norm is one of implicit support, extend their meaning-making strategies when faced with a diagnosis of HIV. In this qualitative study, 13 Black African migrants and refugees living with HIV in New Zealand were interviewed and the transcripts analysed. After their diagnosis, participants began a journey of reconceptualising situational and global meaning. They extended their meaning-making strategies to include a community of like others to gain explicit support. Caregivers in host countries must understand the meaning-making processes of HIV-positive Black African migrants in order to provide competent services that lead to good social and health outcomes. All healthcare and social services workers should regularly assess Black African migrants and refugees living with HIV for positive social connectedness as well as medication adherence and more specific health concerns.

  14. Ethnic differences in blood lipids and dietary intake between UK children of black African, black Caribbean, South Asian, and white European origin: the Child Heart and Health Study in England (CHASE).

    Science.gov (United States)

    Donin, Angela S; Nightingale, Claire M; Owen, Christopher G; Rudnicka, Alicja R; McNamara, Mary C; Prynne, Celia J; Stephen, Alison M; Cook, Derek G; Whincup, Peter H

    2010-10-01

    Ischemic heart disease (IHD) rates are lower in UK black Africans and black Caribbeans and higher in South Asians when compared with white Europeans. Ethnic differences in lipid concentrations may play a part in these differences. The objective was to investigate blood lipid and dietary patterns in UK children from different ethnic groups. This was a cross-sectional study in 2026 UK children (including 285 black Africans, 188 black Caribbeans, 534 South Asians, and 512 white Europeans) attending primary schools in London, Birmingham, and Leicester. We measured fasting blood lipid concentrations and collected 24-h dietary recalls. In comparison with white Europeans, black African children had lower total cholesterol (-0.14 mmol/L; 95% CI: -0.25, -0.04 mmol/L), LDL-cholesterol (-0.10 mmol/L; 95% CI: -0.20, -0.01 mmol/L), and triglyceride concentrations (proportional difference: -0.11 mmol/L; 95% CI: -0.16, -0.06 mmol/L); HDL-cholesterol concentrations were similar. Lower saturated fat intakes (-1.4%; 95% CI: -1.9%, -0.9%) explained the differences between total and LDL cholesterol. Black Caribbean children had total, LDL-cholesterol, HDL-cholesterol, and triglyceride concentrations similar to those for white Europeans, with slightly lower saturated fat intakes. South Asian children had total and LDL-cholesterol concentrations similar to those for white Europeans, lower HDL-cholesterol concentrations (-0.7 mmol/L; 95% CI: -0.11, -0.03 mmol/L), and elevated triglyceride concentrations (proportional difference: 0.14 mmol/L; 95% CI: 0.09, 0.20 mmol/L); higher polyunsaturated and monounsaturated fat intakes did not explain these lipid differences. Only black African children had a blood lipid profile and associated dietary pattern likely to protect against future IHD. The loss of historically lower LDL-cholesterol concentrations among UK black Caribbeans and South Asians may have important adverse consequences for future IHD risk in these groups.

  15. Black History, Inc! Investigating the Production of Black History through Walmart's Corporate Web Site

    Science.gov (United States)

    King, LaGarrett J.; Brown, Anthony L.

    2012-01-01

    Social and public sites are becoming a popular medium for intellectual consumption of Black history. Given the educational climate in which many students' exposure to Black history may come from outside of schools, the authors examine how Walmart's Black History Month Web site produced simplistic and safe narratives about African American history.

  16. FastStats: Health of Black or African American non-Hispanic Population

    Science.gov (United States)

    ... Health of Black or African American non-Hispanic Population Recommend on Facebook Tweet Share Compartir Data are ... Source: Summary Health Statistics Tables for the U.S. Population: National Health Interview Survey, 2015, Table P-1c [ ...

  17. An investigation into the causes of absconding among black African ...

    African Journals Online (AJOL)

    Objective. To discuss the complexities facing the researcher in attempting to detennine reasons for the high rate of absconding from biomedical treatments by black African women diagnosed with breast cancer. Design. Qualitative study based on in-depth interviews and participant observations of the informants, to ascertain ...

  18. Black-tailed Godwits in West African winter staging areas : habitat use and hunting-related mortality

    NARCIS (Netherlands)

    Kleijn, D.; Kamp, van der J.; Monteiro, H.; Ndiaye, I.; Wymenga, E.; Zwarts, L.

    2010-01-01

    The persistence of the Dutch Black-tailed Godwit population depends largely on high adult survival. Adult survival may be influenced by hunting pressure and land use change in the wintering area, the West African coastal zone. Here we examine hunting pressure on and habitat use of Black-tailed

  19. Private Sector Investment in Black Education and Training: Rescuing South African Capitalism from Apartheid's Crisis.

    Science.gov (United States)

    Kraak, Andre

    1989-01-01

    Discusses: (1) the factors contributing to increased involvement by South African business and industry in Black education and training; (2) the Urban Foundation's commitment to non-formal education in Black communities; (3) intervention by American corporations; and (4) the dramatic failure of capitalist initiatives. Contains 55 references. (SV)

  20. Family and Friendship Networks and Obsessive-Compulsive Disorder Among African Americans and Black Caribbeans.

    Science.gov (United States)

    Himle, Joseph A; Taylor, Robert Joseph; Nguyen, Ann W; Williams, Monnica T; Lincoln, Karen D; Taylor, Harry Owen; Chatters, Linda M

    2017-03-01

    Although there is a large literature on the influence of social support on mental health there is limited research on social support and OCD. This is especially the case for African Americans and Black Caribbeans. This study examines the relationship between family and friendship networks and the prevalence of OCD. The analysis is based on the National Survey of American Life a nationally representative sample of African Americans and Black Caribbeans. Variables included frequency of contact with family and friends, subjective closeness with family and friends, and negative interactions (conflict, criticisms) with family members. The results indicated that only negative interaction with family members was significantly associated with OCD prevalence. African Americans and Black Caribbeans with more frequent negative interactions with family members had a higher likelihood of having OCD. Subjective closeness and frequency of contact with family and friends was not protective of OCD. Overall the findings are consistent with previous work which finds that social support is an inconsistent protective factor of psychiatric disorders, but negative interactions with support network members is more consistently associated with mental health problems.

  1. The Black Man in American Society.

    Science.gov (United States)

    Framingham Public Schools, MA.

    GRADE OR AGES: Junior high school. SUBJECT MATTER: The black man in American society. ORGANIZATION AND PHYSICAL APPEARANCE: There are four major parts each with an overview. The four parts concern a) the African heritage of the black man, b) the American exploitation of the black man, c) the black man's contribution to American society, d) the…

  2. Primary familial hypercholesterolaemia in a South African black. A case report

    NARCIS (Netherlands)

    van Wingerden, J. J.

    1981-01-01

    A case of familial hypercholesterolaemia is presented. This is to the best of our knowledge the first report of such a case in a South African black. The modes of presentation and inheritance are discussed and the relevant literature is reviewed

  3. "A Grammar for Black Education beyond Borders": Exploring Technologies of Schooling in the African Diaspora

    Science.gov (United States)

    Givens, Jarvis Ray

    2016-01-01

    Education has been a technology used to sustain black abjection across the African Diaspora. Employing Mills' Racial Contract and Althusser's theory of the Ideological State Apparatuses (ISA) through a racial lens, this article will discuss how white supremacist education has been used to promote the misrecognition of black subjects as sub-human.…

  4. As I see it: a study of African American pastors' views on health and health education in the black church.

    Science.gov (United States)

    Rowland, Michael L; Isaac-Savage, E Paulette

    2014-08-01

    The Black Church is the only institution that has consistently served the interest of African Americans, and there is no other institution in the African American community that rivals its influence (Camara, 2004). The spiritual well-fare, social support, health, and well-being of its people have been one of its main goals. With health disparities of African Americans still at an alarming rate, the Black Church has used informal education as a means to impart knowledge on health, as well as other non-religious and religious topics. One of the avenues least researched within the Black Church is the pastor's perception of its educational role in health and wellness and its efforts to reduce health discrimination and health disparities between African American and European Americans in the U.S. Since social justice appears as a theme and concern in the traditions of many churches, it is only appropriate that, among other things, the Black Church should address the issue of health education and interventions. The purpose of this study was to explore African American pastors' perceptions of the role of the Black Church in providing health care, health education, and wellness opportunities to African Americans. Many pastors reported their church provided some form of health education and/or health screenings. Their perceptions about the important issues facing their congregants versus African Americans in general were quite similar.

  5. Black theology in South Africa – A theology of human dignity and black identity

    Directory of Open Access Journals (Sweden)

    Timothy van Aarde

    2016-08-01

    Full Text Available Black theology in South Africa is still relevant 20 years after the apartheid regime ended. It is a theology that gave to Black South Africans human dignity and a black identity. Black theology in South Africa confronted the imbalances of power and abusive power structures through an affirmation of human dignity and the uniqueness of the identity of black people. The biblical narrative of the Exodus is a definitive narrative in American black theology and liberation theology in overcoming oppression understood as political victimisation. Black theology in South Africa is not primarily about power and economics but also about the rediscovery of human dignity and black identity and to a lesser extent about victimisation. A third generation of black theology in South Africa will gain impetus through a rediscovery of human dignity and identity as its core values instead of a Black American liberation theology of victimisation or a Marxist liberation theology of the eradication of all power or economic imbalances.

  6. Pamidronate treatment for osteogenesis imperfecta in black South Africans.

    Science.gov (United States)

    Henderson, B D; Isaac, N; Mabele, O; Khiba, S; Nkayi, A; Mokoena, T

    2016-05-25

    Osteogenesis imperfecta is a heritable disorder of bone connective tissue. Type III has a high incidence in the black pop-ulation of South Africa. Affected people experience numerous fractures, bone pain and progressive disability. Until the introduction of bisphosphonates to reduce fracture incidence, treatment revolved around orthopaedic and supportive care. Objective. To assess the subjective attitude of patients towards pamidronate treatment. Thirty black patients with osteogenesis imperfecta type III treated at Universitas Hospital were approached and 26 were included in this study. Patients or their parents were interviewed using a standardised researcher-administered questionnaire, either in person or by telephone. Most patients reported a reduction in symptoms, a feeling of increased wellbeing, increased strength and rated the pamidronate treatment highly. The intravenous route of administration and the side-effects experienced were bearable. Overall all patients would recommend this treatment to other affected persons. This is first study to look at bisphosphonate treatment for osteogenesis imperfecta type III in black South Africans. The treatment is well tolerated and highly rated by the patients. Reported improvements and side-effects are similar to those reported in other populations. Using this form of treatment in this population is supported by these findings.

  7. Field Plot Techniques for Black Sigatoka Evaluation in East African Highland Bananas

    Directory of Open Access Journals (Sweden)

    Okoro, JU.

    1997-01-01

    Full Text Available Number of plants per experimental unit and number of replications for the efficient and precise assessment of black sigatoka leaf spot disease caused by Mycosphaerella fijiensis in East African Highland bananas were determined. Two representative cultivars were used. Host response to black sigatoka infection was measured by recording the youngest leaf with necrotic spots. The number of plants per experimental unit was determined, using the methods of maximum curvature and comparison of variances, while the number of replications was estimated by Hatheway's method. The optimum experimental plot size was 3 plants (18 m2 for the beer banana cultivar 'Igitsiri', and 30 plants (180 m2 for the cooking banana cultivar 'Igisahira Gisanzwe', using the comparison of variances method. However, the optimum plot size was 15 plants (90 m2 for both cultivars using the method of maximum curvature. The latter statistical method was preferred because of the low precision of the estimates in the former method. Unreplicated trials with plots of 15 plants could be adequate to assess black sigatoka response in East African bananas if uniform disease pressure exists.

  8. From Black Power to Black Studies: How a Radical Social Movement became an Academic Discipline

    Science.gov (United States)

    Rojas, Fabio

    2007-01-01

    The black power movement helped redefine African Americans' identity and establish a new racial consciousness in the 1960s. As an influential political force, this movement in turn spawned the academic discipline known as Black Studies. Today there are more than a hundred Black Studies degree programs in the United States, many of them located in…

  9. Common roots: a contextual review of HIV epidemics in black men who have sex with men across the African diaspora.

    Science.gov (United States)

    Millett, Gregorio A; Jeffries, William L; Peterson, John L; Malebranche, David J; Lane, Tim; Flores, Stephen A; Fenton, Kevin A; Wilson, Patrick A; Steiner, Riley; Heilig, Charles M

    2012-07-28

    Pooled estimates from across the African diaspora show that black men who have sex with men (MSM) are 15 times more likely to be HIV positive compared with general populations and 8·5 times more likely compared with black populations. Disparities in the prevalence of HIV infection are greater in African and Caribbean countries that criminalise homosexual activity than in those that do not criminalise such behaviour. With the exception of US and African epidemiological studies, most studies of black MSM mainly focus on outcomes associated with HIV behavioural risk rather than on prevalence, incidence, or undiagnosed infection. Nevertheless, black MSM across the African diaspora share common experiences such as discrimination, cultural norms valuing masculinity, concerns about confidentiality during HIV testing or treatment, low access to HIV drugs, threats of violence or incarceration, and few targeted HIV prevention resources. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Body mass index adjustments to increase the validity of body fatness assessment in UK Black African and South Asian children.

    Science.gov (United States)

    Hudda, M T; Nightingale, C M; Donin, A S; Fewtrell, M S; Haroun, D; Lum, S; Williams, J E; Owen, C G; Rudnicka, A R; Wells, J C K; Cook, D G; Whincup, P H

    2017-07-01

    Body mass index (BMI) (weight per height 2 ) is the most widely used marker of childhood obesity and total body fatness (BF). However, its validity is limited, especially in children of South Asian and Black African origins. We aimed to quantify BMI adjustments needed for UK children of Black African and South Asian origins so that adjusted BMI related to BF in the same way as for White European children. We used data from four recent UK studies that made deuterium dilution BF measurements in UK children of White European, South Asian and Black African origins. A height-standardized fat mass index (FMI) was derived to represent BF. Linear regression models were then fitted, separately for boys and girls, to quantify ethnic differences in BMI-FMI relationships and to provide ethnic-specific BMI adjustments. We restricted analyses to 4-12 year olds, to whom a single consistent FMI (fat mass per height 5 ) could be applied. BMI consistently underestimated BF in South Asians, requiring positive BMI adjustments of +1.12 kg m - 2 (95% confidence interval (CI): 0.83, 1.41 kg m - 2 ; PAfricans, requiring negative BMI adjustments for Black African children. However, these were complex because there were statistically significant interactions between Black African ethnicity and FMI (P=0.004 boys; P=0.003 girls) and also between FMI and age group (PAfricans. Ethnic-specific adjustments, increasing BMI in South Asians and reducing BMI in Black Africans, can improve the accuracy of BF assessment in these children.

  11. Barriers to HIV testing for migrant black Africans in Western Europe

    NARCIS (Netherlands)

    Fakoya, A.; Reynolds, R.; Caswell, G.; Shiripinda, I.

    2008-01-01

    Migrant black Africans are disproportionately affected by HIV in Western Europe; we discuss the barriers to HIV testing for sub-Saharan migrants, with particular emphasis on the UK and the Netherlands. Cultural, social and structural barriers to testing, such as access to testing and care, fear of

  12. Black Films in Search of a Home.

    Science.gov (United States)

    Taylor, Clyde

    1983-01-01

    Black filmmakers have produced many films that successfully showcase African-American culture, yet this work is rarely exposed to its intended audience. The Black bourgeoisie, because of their money and social status, must play a role in supporting Black filmmaking and fostering the perception of Black film as part of American popular culture. (GC)

  13. Body mass index adjustments to increase the validity of body fatness assessment in UK Black African and South Asian children

    Science.gov (United States)

    Hudda, M T; Nightingale, C M; Donin, A S; Fewtrell, M S; Haroun, D; Lum, S; Williams, J E; Owen, C G; Rudnicka, A R; Wells, J C K; Cook, D G; Whincup, P H

    2017-01-01

    Background/Objectives: Body mass index (BMI) (weight per height2) is the most widely used marker of childhood obesity and total body fatness (BF). However, its validity is limited, especially in children of South Asian and Black African origins. We aimed to quantify BMI adjustments needed for UK children of Black African and South Asian origins so that adjusted BMI related to BF in the same way as for White European children. Methods: We used data from four recent UK studies that made deuterium dilution BF measurements in UK children of White European, South Asian and Black African origins. A height-standardized fat mass index (FMI) was derived to represent BF. Linear regression models were then fitted, separately for boys and girls, to quantify ethnic differences in BMI–FMI relationships and to provide ethnic-specific BMI adjustments. Results: We restricted analyses to 4–12 year olds, to whom a single consistent FMI (fat mass per height5) could be applied. BMI consistently underestimated BF in South Asians, requiring positive BMI adjustments of +1.12 kg m−2 (95% confidence interval (CI): 0.83, 1.41 kg m−2; Pchildren. However, these were complex because there were statistically significant interactions between Black African ethnicity and FMI (P=0.004 boys; P=0.003 girls) and also between FMI and age group (Pchildren with higher unadjusted BMI and the smallest in older children with lower unadjusted BMI. Conclusions: BMI underestimated BF in South Asians and overestimated BF in Black Africans. Ethnic-specific adjustments, increasing BMI in South Asians and reducing BMI in Black Africans, can improve the accuracy of BF assessment in these children. PMID:28325931

  14. Prostate cancer disparities in Black men of African descent: a comparative literature review of prostate cancer burden among Black men in the United States, Caribbean, United Kingdom, and West Africa

    Directory of Open Access Journals (Sweden)

    Reams R Renee

    2009-02-01

    Full Text Available Abstract Background African American men have the highest prostate cancer morbidity and mortality rates than any other racial or ethnic group in the US. Although the overall incidence of and mortality from prostate cancer has been declining in White men since 1991, the decline in African American men lags behind White men. Of particular concern is the growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry in the Caribbean Islands, United Kingdom and West Africa. This higher incidence of prostate cancer observed in populations of African descent may be attributed to the fact that these populations share ancestral genetic factors. To better understand the burden of prostate cancer among men of West African Ancestry, we conducted a review of the literature on prostate cancer incidence, prevalence, and mortality in the countries connected by the Transatlantic Slave Trade. Results Several published studies indicate high prostate cancer burden in Nigeria and Ghana. There was no published literature for the countries Benin, Gambia and Senegal that met our review criteria. Prostate cancer morbidity and/or mortality data from the Caribbean Islands and the United Kingdom also provided comparable or worse prostate cancer burden to that of US Blacks. Conclusion The growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry follows the path of the Transatlantic Slave Trade. To better understand and address the global prostate cancer disparities seen in Black men of West African ancestry, future studies should explore the genetic and environmental risk factors for prostate cancer among this group.

  15. The role of cognitive style in the stress and coping of black South African adolescents.

    Science.gov (United States)

    van Rooyen, Melinda; Naude, Luzelle; Nel, Lindi; Esterhuyse, Karel

    2014-12-01

    Although stress is a common phenomenon in all phases of life, it can be said that adolescence is a particularly stressful life stage. In South Africa, black adolescents are faced with many stressors and challenges which are placing demands on their emotional and cognitive resources. The aim of this study was to determine whether black South African adolescents with different cognitive styles (i.e. rational or experiential) differ in their levels of stress and coping. Furthermore, the common stressors that black adolescents experience and the coping styles predominantly used by black adolescents could be determined. One hundred and eighty-seven participants (88 males and 99 females) completed the Rational Experiential, the Coping Reponses and the Adolescent Stress Inventory. Adolescents operating from an experiential cognitive style experienced more stress regarding school performance, school attendance, financial pressure and emerging adult responsibility than adolescents operating from a rational cognitive style. Adolescents employing a rational style sought more alternative rewards as a coping strategy, whereas adolescents employing an experiential style relied more on emotional discharge. The findings of this study concur with previous research, but provide a unique perspective on adolescents' stress and coping in this South African context.

  16. An Intersectional Approach for Understanding Perceived Discrimination and Psychological Well-being among African American and Caribbean Black Youth

    OpenAIRE

    Seaton, Eleanor K.; Caldwell, Cleopatra H.; Sellers, Robert M.; Jackson, James S.

    2010-01-01

    The present study examined whether combinations of ethnicity, gender and age moderated the association between perceived discrimination and psychological well-being indicators (depressive symptoms, self-esteem and life satisfaction) in a nationally representative sample of Black youth. The data were from the National Survey of African Life (NSAL), which includes 810 African American and 360 Caribbean Black adolescents. The results indicated main effects such that perceived discrimination was ...

  17. The Black Woman's Burden

    Science.gov (United States)

    Hayes, Dianne

    2012-01-01

    Not even the first lady of the most powerful nation in the world is immune to stereotypes that have plagued Black women since first setting foot on American soil. Stereotypes of being the "angry Black woman" and curiosity about differences in appearance still persist from the academy to 1600 Pennsylvania Ave. As African-American women rise in…

  18. Severe physical violence and Black women's health and well-being.

    Science.gov (United States)

    Lacey, Krim K; Sears, Karen Powell; Matusko, Niki; Jackson, James S

    2015-04-01

    We evaluated the association between intimate partner violence and the mental and physical health status of US Caribbean Black and African American women. We used 2001 to 2003 cross-sectional data from the National Survey of American Life-the most detailed study to date of physical and mental health disorders of Americans of African descent. We assessed participants' health conditions by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (Washington, DC; American Psychological Association) Composite International Diagnostic Interview. We found differences in health conditions between abused African American and Caribbean Black women. There were increased risks for lifetime dysthymia, alcohol dependence, drug abuse, and poor perceived health for African American victims of partner abuse, and binge eating disorder was associated with partner violence among Caribbean Black women. Severe intimate partner violence was associated with negative mental and physical health outcomes for US Black women, with different patterns between African American and Caribbean Blacks. Understanding intimate partner violence experiences of US Black women requires recognition of key intragroup differences, including nativity and immigrant status, and their differential relationships to women's health.

  19. Attitude Of Self Ear Cleaning In Black Africans: Any Benefit? | Afolabi ...

    African Journals Online (AJOL)

    Wax removal compromises the integrity of the ear's defenses. It is a leading cause of otitis externa, Otomycosis and impaired hearing. Aims of the study are to assess the knowledge and implication of self ear cleaning among black Africans. Material and methods: A prospective study carried out at the Tundun-wada ...

  20. Young, Gifted, and Black: Promoting High Achievement among African-American Students.

    Science.gov (United States)

    Perry, Theresa; Steele, Claude; Hilliard, Asa G., III

    In three linked but separate essays, this book explores how African-American students experience school in a society that has historically devalued their intellectual abilities. It calls for a new understanding of the unique obstacles black students face in American schools and points to a variety of educational practices that can mitigate those…

  1. Effects of acute and chronic stress on the L-arginine nitric oxide pathway in black and white South Africans: the sympathetic activity and ambulatory blood pressure in Africans study.

    Science.gov (United States)

    Reimann, Manja; Hamer, Mark; Malan, Nicolaas T; Schlaich, Markus P; Lambert, Gavin W; Ziemssen, Tjalf; Boeger, Rainer H; Malan, Leoné

    2013-10-01

    This study investigated the impact of stress on effectors of the L-arginine/nitric oxide (NO) system including the endogenous inhibitor asymmetric dimethylarginine (ADMA). Black (n = 168) and white (n = 206) South African teachers were exposed to a mental and a physical stressor for 1 minute, respectively. Serum samples for determination of l-arginine, NO metabolites, ADMA, and symmetric dimethylarginine (SDMA) were obtained at rest and during stress exposure. Perception of task stressfulness was assessed on a 7-point Likert scale, and psychological distress was estimated by the General Health Questionnaire. Black South Africans exhibited higher resting levels of NO metabolites (adjusted mean [standard error of the mean] = 11.3 [1.3] versus 3.9 [1.1] μmol/l, p stress were evident for NO metabolites (blacks versus whites: 5.94 [1.55] versus -0.74 [1.25] μmol/l, p = .004) and SDMA (blacks versus whites: -0.02 [0.01] versus 0.02 [0.01] μmol/l, p = .004). Ethnicity-by-psychological distress interaction for stress responses was found for l-arginine/ADMA ratio (p = .027). The l-arginine/NO system is affected by psychosocial distress with higher susceptibility in black South Africans. This interaction may contribute to the higher cardiovascular disease risk in black South Africans.

  2. Cancer incidence profile in sub-Saharan African-born blacks in the United States: Similarities and differences with US-born non-Hispanic blacks.

    Science.gov (United States)

    Medhanie, Genet A; Fedewa, Stacey A; Adissu, Hibret; DeSantis, Carol E; Siegel, Rebecca L; Jemal, Ahmedin

    2017-08-15

    Sub-Saharan African-born blacks (ABs) are one of the fastest-growing populations in the United States. However, to the authors' knowledge, data regarding the cancer burden in this group are lacking, which would inform targeted cancer prevention and control. The authors calculated age-standardized proportional incidence ratios (PIRs) comparing the frequency of the top 15 cancers in ABs with that of US-born non-Hispanic blacks (USBs) by sex and region of birth using incidence data for 2000 through 2012 from the Surveillance, Epidemiology, and End Results (SEER 17) program. Compared with USBs, ABs had significantly higher PIRs of infection-related cancers (liver, stomach, and Kaposi sarcoma), blood cancers (leukemia and non-Hodgkin lymphoma), prostate cancer, and thyroid cancers (females only). For example, the PIR for Kaposi sarcoma in AB versus USB women was 12.06 (95% confidence interval [95% CI], 5.23-18.90). In contrast, ABs had lower PIRs for smoking-related and colorectal cancers (eg, for lung cancer among men, the PIR was 0.30 [95% CI, 0.27-0.34]). Furthermore, cancer occurrence in ABs versus USBs varied by region of birth. For example, the higher PIRs for liver cancer noted among male ABs (PIR, 3.57; 95% CI, 1.79-5.35) and for thyroid cancer in female ABs (PIR, 3.03; 95% CI, 2.03-4.02) were confined to Eastern African-born blacks, whereas the higher PIR for prostate cancer (PIR, 1.90; 95% CI, 1.78, 2.02) was confined to Western African-born blacks. The cancer incidence profile of ABs is different from that of USBs and varies by region of birth, suggesting differences in environmental, cultural, social, and genetic factors. The findings of the current study could stimulate etiologic research and help to inform targeted interventions. Cancer 2017;123:3116-24. © 2017 American Cancer Society. © 2017 American Cancer Society.

  3. Ten Myths, Half-Truths and Misunderstandings About Black History.

    Science.gov (United States)

    Ruffins, Paul

    1997-01-01

    Common myths and misconceptions about Blacks in American history and evidence that refutes them are presented. Issues addressed include Black enslavement patterns, social status within the Black community based on skin color, the legality of slaves learning to read, resistance to slavery, African influences in modern Black culture, Black names and…

  4. Identité et marchandisation : Le cas des black memorabilia et black collectibles Identity and Commodification: The Case of Black Memorabilia and Black Collectibles

    Directory of Open Access Journals (Sweden)

    Eliane Elmaleh

    2009-07-01

    Full Text Available The aim of this article is to raise the issue of the commodification of African American culture, mainly through a certain form of art that has re-emerged with Black memorabilia which paradoxically fit into a black-driven market. However, these items penetrated American culture from 1920 to the 1950s to convey images of black people as lazy, stupid, childlike and happy. This condition of permanent happiness, typified by a broad smile and white teeth, was a fundamental component of this racist and stereotyped imagery. Thus, this article focuses on the thin border between racism and the denunciation of racism, commodification and denunciation of commodification, art and its by-products being always co-opted in the specific logic of private productivity.

  5. Mortality among blacks or African Americans with HIV infection--United States, 2008-2012.

    Science.gov (United States)

    Siddiqi, Azfar-e-Alam; Hu, Xiaohong; Hall, H Irene

    2015-02-06

    A primary goal of the National HIV/AIDS Strategy is to reduce HIV-related health disparities, including HIV-related mortality in communities at high risk for human immunodeficiency virus (HIV) infection. As a group, persons who self-identify as blacks or African Americans (referred to as blacks in this report), have been affected by HIV more than any other racial/ethnic population. Forty-seven percent of persons who received an HIV diagnosis in the United States in 2012 and 43% of all persons living with diagnosed HIV infection in 2011 were black. Blacks also experienced a low 3-year survival rate among persons with HIV infection diagnosed during 2003-2008. CDC and its partners have been pursuing a high-impact prevention approach and supporting projects focusing on minorities to improve diagnosis, linkage to care, and retention in care, and to reduce disparities in HIV-related health outcomes. To measure trends in disparities in mortality among blacks, CDC analyzed data from the National HIV Surveillance System. The results of that analysis indicated that among blacks aged ≥13 years the death rate per 1,000 persons living with diagnosed HIV decreased from 28.4 in 2008 to 20.5 in 2012. Despite this improvement, in 2012 the death rate per 1,000 persons living with HIV among blacks was 13% higher than the rate for whites and 47% higher than the rate for Hispanics or Latinos. These data demonstrate the need for implementation of interventions and public health strategies to further reduce disparities in deaths.

  6. The construction of the Black dance/African Peoples' dance section in Britain: Issues arising for the conceptualisation of related choreographic and dance practices

    OpenAIRE

    Adewole, Funmi

    2016-01-01

    This chapter will discuss the construction of the Black dance/African Peoples’ Dance sector (APD) in Britain in the 1990s. The debate about the definition of the terms Black dance and African peoples’ dance is shown to be part and parcel of the quest for appropriate infrastructure to sustain the work of black dancers and those using African and Diasporan dance forms and aesthetics in their productions. I argue therefore that a fuller understanding of this field of practice can only be gained ...

  7. Soft tissue thickness values for black and coloured South African children aged 6-13 years.

    Science.gov (United States)

    Briers, N; Briers, T M; Becker, P J; Steyn, M

    2015-07-01

    In children, craniofacial changes due to facial growth complicate facial approximations and require specific knowledge of soft tissue thicknesses (STT). The lack of South African juvenile STT standards of particular age groups, sex and ancestry is problematic. According to forensic artists in the South African Police Service the use of African-American values to reconstruct faces of Black South African children yields poor results. In order to perform a facial approximation that presents a true reflection of the child in question, information regarding differences in facial soft tissue at different ages, sexes and ancestry groups is needed. The aims of this study were to provide data on STT of South African Black and Coloured children and to assess differences in STT with respect to age, sex and ancestry. STT was measured using cephalograms of South African children (n=388), aged 6-13 years. After digitizing the images, STT measurements were taken at ten mid-facial landmarks from each image using the iTEM measuring program. STT comparisons between groups per age, sex and ancestry were statistically analyzed. The results showed that STT differences at lower face landmarks are more pronounced in age groups per ancestry as opposed to differences per age and sex. Generally, an increase in STT was seen between 6-10 year old groups and 11-13 year old groups, regardless of ancestry and sex, at the midphiltrum, labiale inferius, pogonion, and beneath chin landmarks. This research created a reference dataset for STT of South African children of Black and Coloured ancestry per age and sex that will be useful for facial reconstruction/approximation of juvenile remains. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  8. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as is hi...

  9. Cancer through black eyes - The views of UK based black men towards cancer: A constructivist grounded theory study.

    Science.gov (United States)

    Mulugeta, Betselot; Williamson, Susan; Monks, Rob; Hack, Thomas; Beaver, Kinta

    2017-08-01

    Little is known about black African (BA) and black African-Caribbean (BAC) men's views towards cancer; yet culture and acculturation can contribute to the way in which people understand, explain and develop their attitudes towards cancer. Hence, cancer prevention and early detection strategies may not be sensitive to United Kingdom (UK)-based black men's views, affecting their awareness of risk factors and early detection services. This study explored the views of UK-based BA and BAC men towards cancer. In collaboration with black community organisations based in four major cities in the UK, 25 participants were recruited using convenience and theoretical sampling methods. Data were collected using 33 semi-structured interviews, and analysed using grounded theory analytic procedures. One core category (cancer through black eyes) and seven sub-categories emerged; 'cultural views', 'religious beliefs', 'avoiding Babylon', 'alienation', 'suspicious mind', 'advertisements and information influence very little', and 'gap in service provision (bridging the gap)'. Participants' views towards cancer were linked to socially constructed perspectives, linked with cultural and religious beliefs, and shaped by what being a black male means in society. Risk factors such as smoking and obesity had different meanings and symbolisation through black eyes. There were macro- and micro-level similarities and differences between BA and BAC men. Cancer services and related public-health campaigns aimed at black men need to understand cancer through black eyes. Public health campaigns based solely on the clinical meaning of cancer are incongruent with black men's understandings of cancer, and therefore ineffective at reducing health inequality. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Knowledge, group-based medical mistrust, future expectations, and perceived disadvantages of medical genetic testing: perspectives of Black African immigrants/refugees.

    Science.gov (United States)

    Buseh, A; Kelber, S; Millon-Underwood, S; Stevens, P; Townsend, L

    2014-01-01

    Reasons for low participation of ethnic minorities in genetic studies are multifactorial and often poorly understood. Based on published literature, participation in genetic testing is low among Black African immigrants/refugees although they are purported to bear disproportionate disease burden. Thus, research involving Black African immigrant/refugee populations that examine their perspectives on participating in genetic studies is needed. This report examines and describes the knowledge of medical genetics, group-based medical mistrust, and future expectations of genetic research and the influence of these measures on the perceived disadvantages of genetic testing among Black African immigrants/refugees. Using a cross-sectional survey design, a nonprobability sample (n = 212) of Black African immigrants/refugees was administered a questionnaire. Participants ranged in age from 18 to 61 years (mean = 38.91, SD = 9.78). The questionnaire consisted of 5 instruments: (a) sociodemographic characteristics, (b) Knowledge of Medical Genetics scale, (c) Group-Based Medical Mistrust Scale, (d) Future Expectations/Anticipated Consequences of Genetics Research scale, and (e) Perceived Disadvantages of Genetic Testing scale. Participants were concerned that genetic research may result in scientists 'playing God,' interfering with the natural order of life. In multivariate analyses, the perceived disadvantages of genetic testing increased as medical mistrust and anticipated negative impacts of genetic testing increased. Increase in genetic knowledge contributed to a decrease in perceived disadvantages. Our findings suggest that recruitment of Black African immigrants/refugees in genetic studies should address potential low knowledge of genetics, concerns about medical mistrust, the expectations/anticipated consequences of genetic research, and the perceived disadvantages of genetic testing.

  11. Comparison of telomere length in black and white teachers from South Africa: the sympathetic activity and ambulatory blood pressure in Africans study.

    Science.gov (United States)

    von Känel, Roland; Malan, Nico T; Hamer, Mark; Malan, Leoné

    2015-01-01

    Telomere length is a marker of biological aging that has been linked to cardiovascular disease risk. The black South African population is witnessing a tremendous increase in the prevalence of cardiovascular disease, part of which might be explained through urbanization. We compared telomere length between black South Africans and white South Africans and examined which biological and psychosocial variables played a role in ethnic difference in telomere length. We measured leukocyte telomere length in 161 black South African teachers and 180 white South African teachers aged 23 to 66 years without a history of atherothrombotic vascular disease. Age, sex, years having lived in the area, human immunodeficiency virus (HIV) infection, hypertension, body mass index, dyslipidemia, hemoglobin A1c, C-reactive protein, smoking, physical activity, alcohol abuse, depressive symptoms, psychological distress, and work stress were considered as covariates. Black participants had shorter (median, interquartile range) relative telomere length (0.79, 0.70-0.95) than did white participants (1.06, 0.87-1.21; p < .001), and this difference changed very little after adjusting for covariates. In fully adjusted models, age (p < .001), male sex (p = .011), and HIV positive status (p = .023) were associated with shorter telomere length. Ethnicity did not significantly interact with any covariates in determining telomere length, including psychosocial characteristics. Black South Africans showed markedly shorter telomeres than did white South African counterparts. Age, male sex, and HIV status were associated with shorter telomere length. No interactions between ethnicity and biomedical or psychosocial factors were found. Ethnic difference in telomere length might primarily be explained by genetic factors.

  12. "It's Like Power to Move": Black Students' Psychosocial Experiences in Black Studies Courses at a Predominantly White Institution

    Science.gov (United States)

    Chapman-Hilliard, Collette; Beasley, Samuel T.

    2018-01-01

    This study examined Black students' experiences in culture-centered courses that focused on the historical and contemporary experiences of Blacks in America and across the African diaspora. Using a qualitative approach, the authors investigated the perceptions of how Black Studies courses shaped the psychosocial experiences and identity…

  13. Black and african students: individuals present, absent voices

    Directory of Open Access Journals (Sweden)

    Roseane Maria de Amorim

    2015-08-01

    Full Text Available This paper aims to describe and analyze some data from an extension project and research titled “The narratives of the self and the effects of affirmative action policies to black students who need of affirmative action and Africans." We have as central issues of our work the following questions: What do the students who need of affirmative action and not unitholders know about the quotas? What do the various African groups who are at university know about the quotas and their experience as a student in the Alagoas’ State? In methodological terms, we use some procedures and instruments of action research to raise our diagnostic procedures and social intervention. It is concluded after investigation that the affirmative action policies in college should be the subject of constant debate whether in academia or in society. There is ignorance on the part of students who need of affirmative action, not unitholders and africans student about the racial quotas, the policies of affirmative action and the collective human rights achievements and socio-historical character.

  14. ‘This is the Age of Woman’: Black Feminism and Black Internationalism in the Works of Una Marson, 1928-1938

    Directory of Open Access Journals (Sweden)

    Imaobong D. Umoren

    2013-04-01

    Full Text Available Una Marson (1905-1965 was an Afro-Jamaican intellectual who in the 1930s became an internationally famous feminist, Pan-Africanist, poet, playwright, journalist and social activist. Between 1932 and 1936 Marson lived in London and became involved in the burgeoning Pan-African movement and a number of British and international women’s and feminist organisations. In 1936, she briefly returned to Jamaica amidst the nationalist movements of the time before journeying back to Britain in 1938, where she remained until 1946. This article builds on and differs from previous scholarship on Marson through its exploration of the changes that took place in her black feminist ideas relating to race, gender and class between 1928 and 1938, and how these influenced her intellectual view concerning black internationalism. This article puts two arguments forward. First, Marson’s engagement with Pan-Africanism and her experiences of racism and sexism in London changed her vision of black feminism. Second, this change contributed to her bringing black feminism into the male-dominated sphere of black internationalism. Thus, it calls for more recognition of Una Marson both as a black feminist and a black internationalist

  15. Evaluation of African black pear pulp and oil as ingredients in bread ...

    African Journals Online (AJOL)

    Bakery fat is important ingrredient that affects the rheological properties of bread crumb. In this work, African black peer pulp and pulp oil were used as substitutions to commercial bakery fat 0%, 25%,50%,75% and 100% levels of substitution. The results obtained show that significant difference (p>0.05) occur between the ...

  16. Precipitation and characterisation of lignin obtained from South African kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, M

    2014-07-01

    Full Text Available stream_source_info Namane_2014_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 637 Content-Encoding ISO-8859-1 stream_name Namane_2014_ABSTRACT.pdf.txt Content-Type text/plain; charset=ISO-8859-1 2014... International Conference on Chemical Thermodynamics and South African Institution of Chemical Engineering Conference, Durban, South Africa, 27 July - 1 August 2014 Precipitation and characterisation of lignin obtained from South African kraft mill black...

  17. Determinants of hazardous drinking among black South African men who have sex with men.

    Science.gov (United States)

    Knox, Justin; Reddy, Vasu; Lane, Tim; Lovasi, Gina; Hasin, Deborah; Sandfort, Theo

    2017-11-01

    There is a known heavy burden of hazardous drinking and its associated health risks among black South African MSM; however, no study to date has identified risk factors for hazardous drinking among this nor any other African MSM population. A cross-sectional survey was conducted among 480 black South African MSM recruited using respondent-driven sampling. All analyses were adjusted using an RDS II estimator. Multivariable logistic regression was used to assess the relationship between demographic characteristics, psychosocial factors, behavioral attributes and hazardous drinking. More than half of the men (62%, 95%CI=56%-68%) screened positive as hazardous drinkers. In multivariable analyses, living in a township (versus the city of Pretoria) (aOR=1.9, 95%CI=1.2-3.1, pchild (aOR=2.6, 95%CI=1.1-6.4, p=.03), having anxiety (aOR=5.4, 95%CI=1.2-24.3, p=.03), and social network drinking behavior (aOR=5.4, 95%CI=1.2-24.3, p=.03) were positively associated with hazardous drinking. Being sexually attracted only to men (aOR=0.3, 95%CI=0.1-0.8, p=.01) was negatively associated with hazardous drinking. Hazardous drinking is highly prevalent among black South African MSM. Multiple indicators of social vulnerability were identified as independent determinants of hazardous drinking. These findings are of heightened concern because these health problems often work synergistically to increase risk of HIV infection and should be taken into consideration by efforts aimed at reducing hazardous drinking among this critical population. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Self-sampling kits to increase HIV testing among black Africans in the UK: the HAUS mixed-methods study.

    Science.gov (United States)

    Seguin, Maureen; Dodds, Catherine; Mugweni, Esther; McDaid, Lisa; Flowers, Paul; Wayal, Sonali; Zomer, Ella; Weatherburn, Peter; Fakoya, Ibidun; Hartney, Thomas; McDonagh, Lorraine; Hunter, Rachael; Young, Ingrid; Khan, Shabana; Freemantle, Nick; Chwaula, Jabulani; Sachikonye, Memory; Anderson, Jane; Singh, Surinder; Nastouli, Eleni; Rait, Greta; Burns, Fiona

    2018-04-01

    Timely diagnosis of human immunodeficiency virus (HIV) enables access to antiretroviral treatment, which reduces mortality, morbidity and further transmission in people living with HIV. In the UK, late diagnosis among black African people persists. Novel methods to enhance HIV testing in this population are needed. To develop a self-sampling kit (SSK) intervention to increase HIV testing among black Africans, using existing community and health-care settings (stage 1) and to assess the feasibility for a Phase III evaluation (stage 2). A two-stage, mixed-methods design. Stage 1 involved a systematic literature review, focus groups and interviews with key stakeholders and black Africans. Data obtained provided the theoretical base for intervention development and operationalisation. Stage 2 was a prospective, non-randomised study of a provider-initiated, HIV SSK distribution intervention targeted at black Africans. The intervention was assessed for cost-effectiveness. A process evaluation explored feasibility, acceptability and fidelity. Twelve general practices and three community settings in London. HIV SSK return rate. Stage 1 - the systematic review revealed support for HIV SSKs, but with scant evidence on their use and clinical effectiveness among black Africans. Although the qualitative findings supported SSK distribution in settings already used by black Africans, concerns were raised about the complexity of the SSK and the acceptability of targeting. These findings were used to develop a theoretically informed intervention. Stage 2 - of the 349 eligible people approached, 125 (35.8%) agreed to participate. Data from 119 were included in the analysis; 54.5% (65/119) of those who took a kit returned a sample; 83.1% of tests returned were HIV negative; and 16.9% were not processed, because of insufficient samples. Process evaluation showed the time pressures of the research process to be a significant barrier to feasibility. Other major barriers were

  19. Black carbon and West African Monsoon precipitation. Observations and simulations

    International Nuclear Information System (INIS)

    Huang, J.; Adams, A.; Zhang, C.; Wang, C.

    2009-01-01

    We have recently investigated large-scale co-variability between aerosol and precipitation and other meteorological variables in the West African Monsoon (WAM) region using long term satellite observations and reanalysis data. In this study we compared the observational results to a global model simulation including only direct radiative forcing of black carbon (BC). From both observations and model simulations we found that in boreal cold seasons anomalously high African aerosols are associated with significant reductions in cloud amount, cloud top height, and surface precipitation. These results suggest that the observed precipitation reduction in the WAM region is caused by radiative effect of BC. The result also suggests that the BC effect on precipitation is nonlinear. (orig.)

  20. British Dance: Black Routes

    OpenAIRE

    Adair, C.; Burt, Ramsay, 1953-

    2016-01-01

    British Dance: Black Routes re-examines the distinctive contributions made to British dance by dancers who are Black. Covering the period 1946 to the present, it presents a radical re-reading of dancers and their companies, placing their achievements within a broader historical, cultural and artistic context. The result of a two year research project, British Dance and the African Diaspora, led by editors Christy Adair and Ramsay Burt, the collection looks at artists working with contempor...

  1. Hematological consequences of a FANCG founder mutation in Black South African patients with Fanconi anemia.

    Science.gov (United States)

    Feben, Candice; Kromberg, Jennifer; Wainwright, Rosalind; Stones, David; Poole, Janet; Haw, Tabitha; Krause, Amanda

    2015-03-01

    Fanconi anemia (FA) is a rare disorder of DNA repair, associated with various somatic abnormalities but characterized by hematological disease that manifests as bone marrow aplasia and malignancy. The mainstay of treatment, in developed nations, is hematopoietic stem cell transplantation (HSCT) with subsequent surveillance for solid organ and non-hematological malignancies. In South Africa, FA in the Black population is caused by a homozygous deletion mutation in the FANCG gene in more than 80% of cases. Many affected patients are not diagnosed until late in the disease course when severe cytopenia and bone marrow aplasia are already present. Most patients are not eligible for HSCT at this late stage of the disease, even when it is available in the state health care system. In this study, the hematological presentation and disease progression in 30 Black South African patients with FA, confirmed to have the FANCG founder mutation, were evaluated and compared to those described in other FA cohorts. Our results showed that patients, homozygous for the FANCG founder mutation, present with severe cytopenia but progress to bone marrow failure at similar ages to other individuals affected with FA of heterogeneous genotype. Further, the incidence of myelodysplastic syndrome is similar to that which has been previously described in other FA cohorts. Although severe cytopenia at presentation may be predicted by a higher number of somatic anomalies, the recognition of the physical FA phenotype in Black South African patients is challenging and may not be useful in expediting referral of suspected FA patients for tertiary level investigations and care. Given the late but severe hematological presentation of FA in Black South African patients, an investigative strategy is needed for earlier recognition of affected individuals to allow for possible HSCT and management of bone marrow disease. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. The importance of biographic research: a South African black nurses' perspective.

    Science.gov (United States)

    Mhlongo, T P

    1999-09-01

    This article is an attempt to highlight the importance of biographic research to South African nursing. The writer believes that a particular attention should be paid to the contributions of South African Black/African nurse practitioners. South Africa has produced remarkable African nurses: they range from nurse Professors and Head of the University Nursing Departments to clinical nursing specialists and nursing administrators. The writer--having used the biographical approach in his Doctoral thesis--will highlight some practical and professional issues around biographic research. For the purpose of this publication, however, discussion will be confined to defining biographic research, reviewing different types of biographies, and discussing the value of the biographical research. Furthermore, the writer will identify some biographic concepts, examine their relationships, draw inferences and (hopefully) emerge with an increased understanding of the impact of biography as scientific concept.

  3. "What Exactly Is a Black?": Interrogating the Reality of Race in Jean Genet's The Blacks

    Directory of Open Access Journals (Sweden)

    Debby Thompson

    2002-06-01

    Full Text Available On the dedication page of The Blacks , Genet writes "One evening an actor asked me to write a play for an all-black cast. But what exactly is a black? First of all, what's his color?" Prefiguring major issues and paradoxes of African American cultural studies today, The Blacks insists on the very real ways in which the black/white racial binary, like the very concept of race itself, is lived and socially enforced, and at the same time argues that the binary is ultimately a fiction, made real through performative reification. Genet's "clown show," ambiguously reversing the blackface minstrelsy tradition, dramatizes how racial identity can become internalized and naturalized through cultural myths of interracial rape and colonialist narratives of a "heart of darkness," an imaginary site from which "black essence" arises. These racist performance traditions and narratives are so powerful and resilient that attempts to protest them become subtle and unwitting ways of re-creating them. The Blacks' parody of the minstrel tradition to interrogate all racial identity is so permanently suspended in a dialectic of both reinforcing the black/white binary and invalidating it, that the play's strategies present vital paradigms for the study of other and diverse interrogations of racial ontologies.

  4. Undoing Racism in America: Help from the Black Church.

    Science.gov (United States)

    Vora, Erika; Vora, Jay A.

    2002-01-01

    Investigated whether a planned engagement of white college students, which had very little contact with African Americans, with members of a black community in a safe, welcoming environment (a black church) would significantly reduce racism. Participant surveys indicated that positive interactions between Blacks and Whites resulted in positive…

  5. Plasma Clot Lysis Time and Its Association with Cardiovascular Risk Factors in Black Africans

    NARCIS (Netherlands)

    Z. de Lange (Zelda); M. Pieters (Marlien); J.C. Jerling (Johann); A. Kruger (Annamarie); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractStudies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid

  6. The Soul of Leadership: African American Students' Experiences in Historically Black and Predominantly White Organizations

    Science.gov (United States)

    Hotchkins, Bryan K.

    2013-01-01

    This study addresses African American students' leadership experiences at predominantly White institutions. Findings indicated participants utilized servant leadership in historically Black organizations and transformational leadership in predominantly White organizations. The differences displayed showed that participants' leadership perceptions…

  7. Articulating cultures: socio-cultural experiences of black female ...

    African Journals Online (AJOL)

    Articulating cultures: socio-cultural experiences of black female immigrant students in South African schools 1. ... Gender and Behaviour ... and worrisome issue is that of the erosion of the social and cultural mores of Black3 immigrant students.

  8. [Localization and registration of the hinge axis in black Africans].

    Science.gov (United States)

    Assi, K D; N'Guessan, K S; N'Dindin, C; Bamba, A

    2003-06-01

    The study of the cinematic method using "SAM" and "Quick Axis of FAG" added to mandibular condyle palpation for the hinge axis limited points, show that the Black Africans mandibular condyle rotation axis position is higher (3.5 mm) and backer (2 mm) than the Caucasians. The axial points are located to between 11 and 12 mm in front of the tragus and between 7 and 8 mm below on the perpendicular line to the furrow defining the tragus superior side to the Ectocanthus.

  9. Metabolic syndrome in Black people of the African diaspora: the paradox of current classification, definition and criteria.

    Science.gov (United States)

    Gaillard, Trudy; Schuster, Dara; Osei, Kwame

    2009-01-01

    According to the third National Health and Nutrition Examination Survey, African Americans have a lower prevalence of metabolic syndrome than do Whites. Recent reports in Blacks in other regions have confirmed these observations, but the rates vary. This lower rate of metabolic syndrome in Blacks can be partly ascribed to the lower prevalent rates of some major components of metabolic syndrome, namely serum triglyceride and high-density lipoprotein cholesterol levels in Blacks. This is in contrast with the higher prevalence of obesity (waist circumference) and blood pressure that meet National Cholesterol Education Program criteria in Blacks. Despite these seemingly favorable lipids and lipoprotein profiles, Blacks continue to have higher cardiovascular disease (CVD) mortality and morbidity, even in the absence of diabetes, than do Whites. Insulin resistance is more prevalent in Blacks than in Whites. However, the relationships among insulin resistance and CVD risk factors such as hypertension, high-density lipoprotein cholesterol, and triglycerides are weak in contrast with Whites. The paradox of more favorable lipid profile and conversely the higher rates of unfavorable blood pressure in Blacks calls into question the validity of the current criteria for metabolic syndrome in Blacks. Thus, it can be argued that each of the components of the metabolic syndrome carry different CVD risk factors in Blacks. The greater CVD mortality and morbidity in Blacks appear to be multifactorial. With the emerging epidemic of noncommunicable diseases, chronic kidney diseases due to both diabetes and hypertension have emerged as major CVD risks that are associated with increasing mortality and morbidity in Blacks. We need to emphasize specific components of metabolic syndrome, specifically blood pressure and chronic kidney disease, that carry higher CVD risk with associated greater morbidity and mortality for primary prevention of CVD and type 2 diabetes in Blacks. To this end, we

  10. Body mass index cut-points to identify cardiometabolic risk in black South Africans.

    Science.gov (United States)

    Kruger, H Salome; Schutte, Aletta E; Walsh, Corinna M; Kruger, Annamarie; Rennie, Kirsten L

    2017-02-01

    To determine optimal body mass index (BMI) cut-points for the identification of cardiometabolic risk in black South African adults. We performed a cross-sectional study of a weighted sample of healthy black South Africans aged 25-65 years (721 men, 1386 women) from the North West and Free State Provinces. Demographic, lifestyle and anthropometric measures were taken, and blood pressure, fasting serum triglycerides, high-density lipoprotein (HDL) cholesterol and blood glucose were measured. We defined elevated cardiometabolic risk as having three or more risk factors according to international metabolic syndrome criteria. Receiver operating characteristic curves were applied to identify an optimal BMI cut-point for men and women. BMI had good diagnostic performance to identify clustering of three or more risk factors, as well as individual risk factors: low HDL-cholesterol, elevated fasting glucose and triglycerides, with areas under the curve >.6, but not for high blood pressure. Optimal BMI cut-points averaged 22 kg/m 2 for men and 28 kg/m 2 for women, respectively, with better sensitivity in men (44.0-71.9 %), and in women (60.6-69.8 %), compared to a BMI of 30 kg/m 2 (17-19.1, 53-61.4 %, respectively). Men and women with a BMI >22 and >28 kg/m 2 , respectively, had significantly increased probability of elevated cardiometabolic risk after adjustment for age, alcohol use and smoking. In black South African men, a BMI cut-point of 22 kg/m 2 identifies those at cardiometabolic risk, whereas a BMI of 30 kg/m 2 underestimates risk. In women, a cut-point of 28 kg/m 2 , approaching the WHO obesity cut-point, identifies those at risk.

  11. Black Thyroid Associated with Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Emad Kandil

    2010-01-01

    Full Text Available Objective. Black thyroid is a rare pigmented change seen almost exclusively in patients upon minocycline ingestion, and the process has previously been thought to be generally benign. There have been 61 reported cases of black thyroid. We are aware of 13 cases previously reported in association with thyroid carcinoma. This paper reports six patients with black thyroid pigmentation in association with thyroid carcinoma. Design. The medical records of six patients who were diagnosed with black thyroid syndrome, all of whom underwent thyroid surgery, were reviewed. Data on age, gender, race, preoperative fine needle aspiration biopsy (FNA, thyroid function levels, and pathology reports were collected. Main Outcome. The mean age was 60 years. There were 5 females, 4 of whom were African American. All patients were clinically and biochemically euthyroid. Black pigmentation was not diagnosed in preoperative FNA, and only one patient had a preoperative diagnosis of papillary thyroid carcinoma. The other patients underwent surgery and were found to have black pigmentation of the thyroid associated with carcinoma. Conclusions. FNA does not diagnose black thyroid, which is associated with thyroid carcinoma. Thyroid glands with black pigmentation deserve thorough pathologic examination, including several sections of each specimen.

  12. South African managers' perceptions of black economic empowerment

    African Journals Online (AJOL)

    8Key words: transformation, black economic empowerment (BEE), broad-based black economic empowerment .... mclviiCode series reference ... range of available literature from articles and books as well as newspaper clippings was studied ...

  13. Familial Influences on Poverty Among Young Children in Black Immigrant, U.S.-born Black, and Nonblack Immigrant Families

    Science.gov (United States)

    Thomas, Kevin J. A.

    2014-01-01

    This study examines how familial contexts affect poverty disparities between the children of immigrant and U.S.-born blacks, and among black and nonblack children of immigrants. Despite lower gross child poverty rates in immigrant than in U.S.-born black families, accounting for differences in family structure reveals that child poverty risks among blacks are highest in single-parent black immigrant families. In addition, within two-parent immigrant families, child poverty declines associated with increasing assimilation are greater than the respective declines in single-parent families. The heads of black immigrant households have more schooling than those of native-black households. However, increased schooling has a weaker negative association with child poverty among the former than among the latter. In terms of racial disparities among the children of immigrants, poverty rates are higher among black than nonblack children. This black disadvantage is, however, driven by the outcomes of first-generation children of African and Hispanic-black immigrants. The results also show that although children in refugee families face elevated poverty risks, these risks are higher among black than among nonblack children of refugees. In addition, the poverty-reducing impact associated with having an English-proficient household head is about three times lower among black children of immigrants than among non-Hispanic white children of immigrants. PMID:21491186

  14. Looking for the invisible universe - Black matter, black energy, black holes

    International Nuclear Information System (INIS)

    Elbaz, David

    2016-01-01

    As the discovery of the expansion of the universe and of black holes put the study of cosmology into question again because it now refers to invisible things such as black holes, black energy and black matter, the author proposes an other view on the universe within such a context. He first discusses these three enigmas of black matter, black energy and black holes. In a second part, he addresses, discusses and comments five illusions: the Uranian illusion (questions of the existence of an anti-world, of black matter temperature), the Mercurian illusion (quantum gravity, the string theory), the Martian illusion (a patchwork universe, the illusion of the infinite), the cosmic Maya (the John Wheeler's cup, the holographic universe), and the narcissistic illusion

  15. Black Tribal African Religion with Some Emphasis on Christianity and Islam in Africa.

    Science.gov (United States)

    Emmons, Marian

    This 6th grade social studies unit delves into the belief systems and external religious, cultural practices of Black Africans. It is part of a series of guides developed by the Public Education Religion Studies Center at Wright State University. Study is focused upon the Ashanti tribe of Ghana knowing that although the multiplicity of tribes have…

  16. Black doctors and discrimination under South Africa's apartheid regime.

    Science.gov (United States)

    Digby, Anne

    2013-04-01

    This article discusses an under-researched group and provides an analytical overview of the comparative experiences of African, Indian and Coloured doctors at South African universities during the apartheid era. It probes diversity of experience in training and practice as well as gendered differentiation amongst black students before going on to discuss the careers and political activism of black doctors as well as the impact of recent transformational change on their position. It briefly assesses how singular this South African experience was.

  17. Time and Quest of Identity of the African-American Character: George Schuyler's Black No More

    Directory of Open Access Journals (Sweden)

    Hayder Naji Shanbooj Alolaiwi

    2017-04-01

    Full Text Available This paper attempts to examine the theme of “passing,” viewed as a metaphor of race that marks a step forward from the painful reality of the Middle Passage to “passing,” as both physical reality and metaphor, and to find out the underlying causes of the passing character in George Schyler's Black No More in the light of social and historical dimensions. The study investigates the aspects of “passing”  manifested by the African-American who is often viewed as an “appendage” to the rest of society, blacks have struggled to attain the success, equality, and overall collective consciousness of the American society, while simultaneously creating and maintaining and identity of their own. Blacks have been and continue to be socially, economically, educationally, and politically disenfranchised and therefore cannot completely find unity within an American system that continuously seeks to reaffirm their inferiority.

  18. Strong, female and Black: Stereotypes of African Caribbean women's body shape and their effects on clinical encounters.

    Science.gov (United States)

    Andrews, Nicole; Greenfield, Sheila; Drever, Will; Redwood, Sabi

    2017-03-01

    The aim of this article is to explore how tendencies to stereotype minority ethnic groups intersect with lay discourses about them in ways that can reproduce cultural prejudices and reinforce inequalities in access to services and health outcomes. Drawing upon Black feminist and cultural studies literature, we present a theoretical examination, the stereotypes of the Black woman as 'mammy' and 'matriarch'. We suggest that the influence of these two images is central to understanding the normalisation of the larger Black female body within African Caribbean communities. This representation of excess weight contradicts mainstream negative discourses of large bodies that view it as a form of moral weakness. Seeking to stimulate reflection on how unacknowledged stereotypes may shape clinical encounters, we propose that for Black women, it is the perception of strength, tied into these racial images of 'mammy' and 'matriarch' which may influence when or how health services or advice are both sought by them and offered to them. This has particular significance in relation to how body weight and weight management are/are not talked about in primary care-based interactions and what support Black women are/are not offered. We argue that unintentional bias can have tangible impacts and health outcomes for Black women and possibly other minority ethnic groups.

  19. Political shifts and black theatre in South Africa

    NARCIS (Netherlands)

    Rangoajane, Francis L.

    2011-01-01

    Oral communication, especially through performance, has always been the basis through which Africans/blacks communicated. This became particularly so under apartheid given the fact that blacks were denied a voice, and theatre gave them that voice. The democratisation of South Africa has not only

  20. Black-Brown Relations and Stereotypes.

    Science.gov (United States)

    Mindiola, Tatcho Jr.; Niemann, Yolanda Flores; Rodriguez, Nestor

    This book analyzes how African and Hispanic Americans perceive and interact with one another, highlighting black-brown relations in Houston, Texas, one of the largest cities with a majority ethnic population and one in which Hispanic Americans outnumber African Americans. Using results from several sociological studies, the book examines: how each…

  1. Ethnic differences in mental illness and mental health service use among Black fathers.

    Science.gov (United States)

    Doyle, Otima; Joe, Sean; Caldwell, Cleopatra H

    2012-05-01

    We have presented nationally representative data on the prevalence and correlates of mental illness and mental health service use among African American and Caribbean Black (US-born and foreign-born) fathers in the United States. We have reported national estimates of lifetime and 12-month prevalence rates of mental illness, correlates, and service use among African American (n = 1254) and Caribbean Black (n = 633) fathers using data from the National Survey of American Life, a national household survey of Black Americans. We used bivariate cross-tabulations and Cox proportional hazards regression approaches and adjusted for the National Survey of American Life's complex sample design. The prevalence of mental illness, sociodemographic correlates, and service use among Black fathers varied by ethnicity and nativity. US-born Caribbean Black fathers had alarmingly high rates of most disorders, including depression, anxiety, and substance disorders. Mental health service use was particularly low for African American and foreign-born Caribbean Black fathers. These results demonstrate the need for more research on the causes and consequences of mental illness and the help-seeking behavior of ethnically diverse Black fathers.

  2. The politics of black patients' identity: ward-rounds on the 'black side' of a South African psychiatric hospital.

    Science.gov (United States)

    Swartz, L

    1991-06-01

    There are many macrosocial studies of the political organisation of health and mental health care in South Africa, and the maldistribution of resources by race is well known. Little attention, however, has been given to the minutiae of the negotiation of power in the clinical setting. This article, which reports on part of a larger study of aspects of culture in South African psychiatry, focuses on interactions in ward-rounds on the 'Black side' of a South African psychiatric hospital. Through analysis of cases, the complexity of interpreting what transpires in such a setting and the central role that the concept of culture has in debates amongst staff members are demonstrated. Close analysis demonstrates the inadequacy of models which seek to locate the institutional racism of apartheid psychiatry in the motives of individual clinicians. Clinicians may simultaneously reproduce and subvert aspects of apartheid practice. A consideration of the social positioning of the clinician both as a South African and as a practitioner of psychiatry is central to the development of psychiatry in a post-apartheid South Africa.

  3. Pan-Africanism, the Mystique of World Black Unity: An Afro-American Scholar's Sojourn in Africa.

    Science.gov (United States)

    Staples, Robert

    1977-01-01

    The author explores the ideology of Pan-Africanism in terms of the social and economic position of Blacks in the United States. He briefly describes his visit to Africa (Senegal and Nigeria) and the effects that this experience has had in forming his political viewpoint. (MC)

  4. [Plummer-Vinson syndrome or related syndrome in 3 black African women].

    Science.gov (United States)

    Aubry, P; Oddes, B; Chazouillères, O; Lebourgeois, M; Delanoue, G; Seurat, P L

    1985-01-01

    The Plummer-Vinson syndrome or "sideropenic dysphagia" is exceptional among Blacks. One case was recently reported in a female patient from Guadeloupe. This study pertains to three cases observed in Senegalese Black women aged 28, 27, and 41 years. These three women were admitted for a dysphagia, in fact in evidence 10, 4, and 7 years respectively before the diagnosis was made. A clinical anemia was noted twice in addition to mucocutaneous disorders (cases 1 and 2). The laboratory tests showed in all three cases a hypochromic microcytic sideropenic anemia (serum iron levels at 32, 14, and 31 mcg 100 ml respectively). Barium swallow films showed esophageal rings in front of C5-C6 (case 1) of T2-T3 (case 2) and a web of fine mucosal folds in front of C5-C6 (case 3). These films were confirmed cineradiographically by esophagoscopy. The treatment consisted of blood transfusions (cases 1 and 2) and administration of iron by injections and or per os. The endoscopic exams were repeated two or three times. Medical treatment rapidly changed the course of disease for the better. No cause for bleeding was found. A chemical achlorhydria (case 1), a provoked hypoachlorhydria (cases 2 and 3) can be retained as associated factors. In light of the frequency of esophageal membranes in the general population and the incidence of sideropenic anemias among African women, the Plummer-Vinson syndrome should be more often detected in Black Africa.

  5. Addressing the problem of obesity and associated cardiometabolic risk in black South African women - time for action!

    Science.gov (United States)

    Goedecke, Julia H

    2017-01-01

    The PhD thesis of Gradidge, entitled 'Factors associated with obesity and metabolic syndrome in an ageing cohort of black women living in Soweto, Johannesburg (Study of Women in and Entering Endocrine Transition [SWEET])', attempts to understand the determinants of obesity and metabolic syndrome (MetS) in a population of urban-dwelling black South African women. A conceptual framework is presented, which positions obesity as the central risk factor for MetS, and includes the possible influence of socioeconomic status, lifestyle behaviours and body size perceptions, as key determinants of obesity. This commentary focuses on the two main findings of Gradidge's thesis, namely, (i) physical activity and sedentary behaviour, and (ii) body composition and adiponectin, as risk factors for obesity and MetS in black South African women. Despite a high prevalence of obesity (48%), Gradidge showed that 75% of the women taking part in the study were meeting WHO guidelines on physical activity. This commentary suggests that the relationship between physical activity and cardiometabolic risk may be confounded by socioeconomic status. Alternatively, the intensity, and not necessarily the volume, of activity, as well as high rates of sedentary behaviour are posited as important determinants of obesity and MetS in black South African women. Accordingly, this commentary questions the veracity of the WHO guidelines on physical activity in developing countries, where most women meet the guidelines but have very poor cardiorespiratory fitness, are obese and are at high risk of MetS. Gradidge also showed that the most consistent and significant correlate of MetS in this cohort of middle-aged women was low serum levels of adiponectin. This commentary highlights various lifestyle interventions that have been shown to increase adiponectin levels. Finally, the importance of immediate action to address the problem of obesity and MetS is emphasised.

  6. Engaging black sub-Saharan African communities and their gatekeepers in HIV prevention programs: Challenges and strategies from England

    Directory of Open Access Journals (Sweden)

    Mathew Nyashanu

    2016-12-01

    Full Text Available Objective: HIV infection is a sensitive issue in black communities [Serrant-Green L. Black Caribbean men, sexual health decisions and silences. Doctoral thesis. Nottingham School of Nursing, University of Nottingham; 2004]. Statistics show black sub-Saharan African (BSSA communities disproportionately constitute two-thirds of people with HIV [Heath Protection Agency. Health protection report: latest infection reports-GOV.UK; 2013]. African communities constitute 30% of people accessing HIV treatment in the United Kingdom yet represent less than 1% of the population [Health Protection Agency. HIV in the United Kingdom: 2012 report; 2012], [Department of Health. DVD about FGM. 2012. Available from fgm@dh.gsi.gov.uk.]. This article explores the sociocultural challenges in engaging BSSA communities in HIV prevention programs in England and possible strategies to improve their involvement. Methods: Twelve focus group discussions and 24 semistructured interviews were conducted in a 2-year period with participants from the BSSA communities and sexual health services in the West Midlands, England. The research was supported by the Ubuntu scheme, a sexual health initiative working with African communities in Birmingham, England. Results: Ineffective engagement with African communities can hinder the effectiveness of HIV prevention programs. Skills and strategies sensitive to BSSA culture are important for successful implementation of prevention programs. HIV prevention programs face challenges including stigma, denial, and marginalized views within BSSA communities. Conclusion: Networking, coordination, and cultural sensitivity training for health professionals are key strategies for engaging BSSA communities in HIV prevention programs.

  7. Community and Christianity in the Black Church.

    Science.gov (United States)

    Morris, Joseph R.; Robinson, Dianne T.

    1996-01-01

    Explores the experience of Christianity for many African Americans and how such experience provides a foundation for social activism. Discusses Black church burnings with respect to the more traditional Christian African American view of religion. Explores implications for incorporating the religious traditions of Christian African Americans into…

  8. Rural–urban variations in age at menarche, adult height, leg-length and abdominal adiposity in black South African women in transitioning South Africa

    Science.gov (United States)

    2018-01-01

    Abstract Background: The pre-pubertal socioeconomic environment may be an important determinant of age at menarche, adult height, body proportions and adiposity: traits closely linked to adolescent and adult health. Aims: This study explored differences in age at menarche, adult height, relative leg-length and waist circumference between rural and urban black South African young adult women, who are at different stages of the nutrition and epidemiologic transitions. Subjects and methods: We compared 18–23 year-old black South African women, 482 urban-dwelling from Soweto and 509 from the rural Mpumalanga province. Age at menarche, obstetric history and household socio-demographic and economic information were recorded using interview-administered questionnaires. Height, sitting-height, hip and waist circumference were measured using standardised techniques. Results: Urban and rural black South African women differed in their age at menarche (at ages 12.7 and 14.5 years, respectively). In urban women, a one-year increase in age at menarche was associated with a 0.65 cm and 0.16% increase in height and relative leg-length ratio, respectively. In both settings, earlier age at menarche and shorter relative leg-length were independently associated with an increase in waist circumference. Conclusions: In black South African women, the earlier onset of puberty, and consequently an earlier growth cessation process, may lead to central fat mass accumulation in adulthood. PMID:29557678

  9. Rural-urban variations in age at menarche, adult height, leg-length and abdominal adiposity in black South African women in transitioning South Africa.

    Science.gov (United States)

    Said-Mohamed, Rihlat; Prioreschi, Alessandra; Nyati, Lukhanyo H; van Heerden, Alastair; Munthali, Richard J; Kahn, Kathleen; Tollman, Stephen M; Gómez-Olivé, Francesc Xavier; Houle, Brian; Dunger, David B; Norris, Shane A

    2018-03-01

    The pre-pubertal socioeconomic environment may be an important determinant of age at menarche, adult height, body proportions and adiposity: traits closely linked to adolescent and adult health. This study explored differences in age at menarche, adult height, relative leg-length and waist circumference between rural and urban black South African young adult women, who are at different stages of the nutrition and epidemiologic transitions. We compared 18-23 year-old black South African women, 482 urban-dwelling from Soweto and 509 from the rural Mpumalanga province. Age at menarche, obstetric history and household socio-demographic and economic information were recorded using interview-administered questionnaires. Height, sitting-height, hip and waist circumference were measured using standardised techniques. Urban and rural black South African women differed in their age at menarche (at ages 12.7 and 14.5 years, respectively). In urban women, a one-year increase in age at menarche was associated with a 0.65 cm and 0.16% increase in height and relative leg-length ratio, respectively. In both settings, earlier age at menarche and shorter relative leg-length were independently associated with an increase in waist circumference. In black South African women, the earlier onset of puberty, and consequently an earlier growth cessation process, may lead to central fat mass accumulation in adulthood.

  10. Standard Black English: Upheld by What Standard of Tolerance?

    Science.gov (United States)

    Denson, Marquita D.

    1995-01-01

    Explains how teachers might go about equitably and fairly teaching standard written English when African American students in the class speak black English. Argues that black English, which has been 400 years in the making, is worthy of tolerance and respect for all its richness. (TB)

  11. The emergence of the Black Methodist Consultation and its possible ...

    African Journals Online (AJOL)

    2015-06-04

    Jun 4, 2015 ... address during the South African apartheid rule, a view which black theologians and church .... the impact of racism on self-hate was created by the slogan, ..... white culture, blackness is associated with bad mystique, danger ...

  12. Motivators and deterrents to blood donation among Black South Africans: a qualitative analysis of focus group data.

    Science.gov (United States)

    Muthivhi, T N; Olmsted, M G; Park, H; Sha, M; Raju, V; Mokoena, T; Bloch, E M; Murphy, E L; Reddy, R

    2015-08-01

    South Africa has a markedly skewed representation where the majority of blood (62%) is presently collected from an ethnically White minority. This study seeks to identify culturally specific factors affecting motivation of donors in South Africa. We performed a qualitative study to evaluate motivators and deterrents to blood donation among Black South Africans. A total of 13 focus groups, comprising a total of 97 Black South Africans, stratified by age and geographic location were conducted. Transcripts of the interviews were analysed using a coding framework by Bednall & Bove. Participants made 463 unique comments about motivators focusing primarily on promotional communications (28%), incentives (20%) and prosocial motivation (16%). Participants made 376 comments about deterrents which focused primarily on fear (41%), negative attitudes (14%) and lack of knowledge (10%). Although prosocial motivation (altruism) was the most frequently mentioned individual motivator, promotional communication elicited more overall comments by participants. As reported by many authors, fear and lack of awareness were strong deterrents, but scepticism engendered by perceived racial discrimination in blood collection were unique to the South African environment. © 2015 British Blood Transfusion Society.

  13. Black South African freshmen's experience of first coitus and contraception.

    Science.gov (United States)

    Nicholas, L

    1994-01-01

    An anonymous questionnaire investigating Black South African first-year college students' experience of first intercourse and contraception was administered during the February 1993 orientation at a Black university. 754 females and 959 males of mean age 20.4 years in an age range of 16-50 years participated. 96.5% of the respondents were single. The study findings relate to the 894 single students who reported having experienced sexual intercourse. Male and female respondents' mean ages at first intercourse were, respectively, 15.5 and 17.8 years. 35.7% of males and 32.8% of females reported not using contraception during first intercourse, 12.3% of males and 7.1% of females were unsure, and 6.2% reported using withdrawal. 36.8% reported not using a condom because first sexual intercourse was unplanned, while 38.1% simply did not think about contraception at the time. Peers were reported as the primary first source of learning about sexual intercourse as well as the preferred source. These findings lend support to the need to target safer sex messages to college freshmen in this setting. In so doing, safer sex behavior can be encouraged and possibly adopted before high-risk sex behavior patterns develop.

  14. Social Determinants of Perceived Discrimination among Black Youth: Intersection of Ethnicity and Gender.

    Science.gov (United States)

    Assari, Shervin; Caldwell, Cleopatra Howard

    2018-02-15

    Most of the existing sociological and epidemiological literature has focused on the protective effects of high socioeconomic status (SES) on population health through reducing exposure to risk factors and increasing human and material resources that can mitigate adversities. Recent studies, however, have documented poor mental health of high SES Blacks, particularly African American males and Caribbean Black females. The literature also shows a link between perceived discrimination and poor mental health. To better understand the extra costs of upward social mobility for minority populations, this study explored ethnic by gender variations in the associations between SES indicators and perceived discrimination in an ethnically diverse national sample of Black youth. This study included 810 African American and 360 Caribbean Black youth who were sampled in the National Survey of American Life-Adolescent supplement (NSAL-A). Three SES indicators (financial hardship, family income, and income to needs ratio) were the independent variables. The dependent variable was perceived (daily) discrimination. Age was the covariate. Ethnicity and gender were the focal moderators. Linear regressions were used for data analysis in the pooled sample and also based on the intersection of ethnicity and gender. Considerable gender by ethnicity variations were found in the patterns of the associations between SES indicators and perceived discrimination. Financial hardship was a risk factor for perceived discrimination in African American males only. High family income and income to needs ratio were associated with high (but not low) perceived discrimination in African American males and Caribbean Black females. SES indicators were not associated with perceived discrimination for African American females or Caribbean Black males. When it comes to Black youth, high SES is not always protective. Whether SES reduces or increases perceived discrimination among Black youth depends on the

  15. Social Determinants of Perceived Discrimination among Black Youth: Intersection of Ethnicity and Gender

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2018-02-01

    Full Text Available Most of the existing sociological and epidemiological literature has focused on the protective effects of high socioeconomic status (SES on population health through reducing exposure to risk factors and increasing human and material resources that can mitigate adversities. Recent studies, however, have documented poor mental health of high SES Blacks, particularly African American males and Caribbean Black females. The literature also shows a link between perceived discrimination and poor mental health. To better understand the extra costs of upward social mobility for minority populations, this study explored ethnic by gender variations in the associations between SES indicators and perceived discrimination in an ethnically diverse national sample of Black youth. This study included 810 African American and 360 Caribbean Black youth who were sampled in the National Survey of American Life—Adolescent supplement (NSAL-A. Three SES indicators (financial hardship, family income, and income to needs ratio were the independent variables. The dependent variable was perceived (daily discrimination. Age was the covariate. Ethnicity and gender were the focal moderators. Linear regressions were used for data analysis in the pooled sample and also based on the intersection of ethnicity and gender. Considerable gender by ethnicity variations were found in the patterns of the associations between SES indicators and perceived discrimination. Financial hardship was a risk factor for perceived discrimination in African American males only. High family income and income to needs ratio were associated with high (but not low perceived discrimination in African American males and Caribbean Black females. SES indicators were not associated with perceived discrimination for African American females or Caribbean Black males. When it comes to Black youth, high SES is not always protective. Whether SES reduces or increases perceived discrimination among Black youth

  16. Forging a Collaborative Relationship between the Black Church and the Counseling Profession

    Science.gov (United States)

    Adksion-Bradley, Carla; Johnson, Darrell; Sanders, JoAnn Lipford; Duncan, Lonnie; Holcomb-McCoy, Cheryl

    2005-01-01

    In the field of counseling, there has been a growing awareness of the important role the Black church plays in African American communities. Although counseling professionals have begun recognizing the influence the Black church has in the lives of African Americans, there seems to be little information on how counselors can collaborate with…

  17. Factors affecting behaviours that address HIV risk among Black and White South Africans

    OpenAIRE

    K. Peltzer

    2002-01-01

    The aim of this study was to identify factors affecting HIV risk reduction among 150 Black and 150 White South Africans chosen by systematic random sampling. Main outcome measures included sexual behaviour and condom use, knowledge about correct condom use, intention of condom use, behavioural norms, attitudes, normative beliefs, and subjective norms about condoms, HIV/AIDS health beliefs, and HIV risk behaviour. Bivariate analysis gave positive significant relations among being single, age, ...

  18. Gender and Ethnic Differences in the Association Between Obesity and Depression Among Black Adolescents.

    Science.gov (United States)

    Assari, Shervin; Caldwell, Cleopatra Howard

    2015-12-01

    This study aimed to investigate the association between obesity and major depression disorder (MDD) in a nationally representative sample of Black adolescents in the USA. The study also tested the effects of ethnicity and gender as possible moderators. Data came from the National Survey of American Life (NSAL)-Adolescents, a representative household mental health survey of Black adolescents in the USA. Participants consisted of 1170 Black adolescents (810 African Americans and 360 Caribbean Blacks). Obesity was defined determined by the cutoff points based on the body mass index (BMI) appropriate for age and gender. Twelve-month MDD was measured using the World Mental Health Composite International Diagnostic Interview (CIDI). In the first step, the association between obesity and MDD in the pooled sample, controlling for the main effects of gender and ethnicity. In the next steps, two interactions were tested: (1) obesity and ethnicity and (2) obesity and gender. Although any associations between obesity and MDD in the pooled sample of Blacks were not found, there was a significant interaction between ethnicity and obesity on MDD. Upon testing the associations across intersections of ethnicity and gender, a positive association was found among Caribbean Black females but not Caribbean Black males, African American males, or African American female. The link between BMI and MDD among Blacks depends on ethnicity and gender, and risk of comorbid depression among Black youth with obesity is highest among Caribbean Black females.

  19. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  20. Comparison of equations for estimating glomerular filtration rate in screening for chronic kidney disease in asymptomatic black Africans: a cross sectional study.

    Science.gov (United States)

    Omuse, Geoffrey; Maina, Daniel; Mwangi, Jane; Wambua, Caroline; Kanyua, Alice; Kagotho, Elizabeth; Amayo, Angela; Ojwang, Peter; Erasmus, Rajiv

    2017-12-20

    Several equations have been developed to estimate glomerular filtration rate (eGFR). The common equations used were derived from populations predominantly comprised of Caucasians with chronic kidney disease (CKD). Some of the equations provide a correction factor for African-Americans due to their relatively increased muscle mass and this has been extrapolated to black Africans. Studies carried out in Africa in patients with CKD suggest that using this correction factor for the black African race may not be appropriate. However, these studies were not carried out in healthy individuals and as such the extrapolation of the findings to an asymptomatic black African population is questionable. We sought to compare the proportion of asymptomatic black Africans reported as having reduced eGFR using various eGFR equations. We further compared the association between known risk factors for CKD with eGFR determined using the different equations. We used participant and laboratory data collected as part of a global reference interval study conducted by the Committee of Reference Intervals and Decision Limits (C-RIDL) under the International Federation of Clinical Chemistry (IFCC). Serum creatinine values were used to calculate eGFR using the Cockcroft-Gault (CG), re-expressed 4 variable modified diet in renal disease (4v-MDRD), full age spectrum (FAS) and chronic kidney disease epidemiology collaboration equations (CKD-EPI). CKD classification based on eGFR was determined for every participant. A total of 533 participants were included comprising 273 (51.2%) females. The 4v-MDRD equation without correction for race classified the least number of participants (61.7%) as having an eGFR equivalent to CKD stage G1 compared to 93.6% for CKD-EPI with correction for race. Only age had a statistically significant linear association with eGFR across all equations after performing multiple regression analysis. The multiple correlation coefficients for CKD risk factors were higher for

  1. Do African Lives Matter to Black Lives Matter? Youth Uprisings and the Borders of Solidarity

    Science.gov (United States)

    Strong, Krystal

    2018-01-01

    Despite experiencing a proliferation of youth-led mobilizations in recent years, Africa remains peripheral to the analysis of the U.S.-centered Movement for Black Lives (M4BL). This article explores points of convergence and tension between African uprisings and the M4BL, with a focus on two movements at the intersection of education and activism:…

  2. 'My child did not like using sun protection': practices and perceptions of child sun protection among rural black African mothers.

    Science.gov (United States)

    Kunene, Zamantimande; Albers, Patricia N; Lucas, Robyn M; Banwell, Cathy; Mathee, Angela; Wright, Caradee Y

    2017-08-25

    Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child's 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later. Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade). Most mothers (97%) liked the sun protection equipment. However, many (78 of 86) reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use. Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.

  3. Characteristics of genetics-related news content in Black weekly newspapers.

    Science.gov (United States)

    Caburnay, C A; Babb, P; Kaphingst, K A; Roberts, J; Rath, S

    2014-01-01

    BACKGROUND/AIMS/OBJECTIVES: The media are an important source of health information, especially for those with less access to regular health care. Black news outlets such as Black newspapers are a source of health information for African Americans. This study characterized media coverage of genetics-related information in Black weekly newspapers and general audience newspapers from the same communities. All health stories in a sample of 24 Black weekly newspapers and 12 general audience newspapers from January 2004 to December 2007 were reviewed for genetics-related stories. These stories were further coded for both journalistic and public health variables. Of all health-related stories identified, only 2% (n = 357) were considered genetics related. Genetics-related stories in Black newspapers - compared to those in general audience newspapers - were larger, more locally and racially relevant, and more likely to contain recommendations or action steps to improve health or reduce disease risks and to mention the importance of knowing one's family history. Stories in general audience newspapers were more likely to discuss causes of disease, mention genetic testing or therapy, and suggest a high/moderate degree of genetic determinism. Black newspapers are a viable communication channel to disseminate findings and implications of human genome research to African American audiences.

  4. Huntington\\'s disease: Genetic heterogeneity in black African patients

    African Journals Online (AJOL)

    Objective. Huntington's disease (HD) has been reported to occur rarely in black patients. A new genetic variant– Huntington's disease-like 2 (HDL2) – occurring more frequently in blacks, has recently been described. The absence of an expanded trinucleotide repeat at the chromosome 4 HD locus was previously regarded ...

  5. Motor neuron disease in blacks | Cosnett | South African Medical ...

    African Journals Online (AJOL)

    A series of 86 black, Indian and white patients with motor neuron disease were analysed retrospectively. Although the material does not allow statistically valid conclusions, there are sufficient cases among blacks to allow two prima facie observations in this population group: (i) motor neuron disease has an earlier age of ...

  6. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.

    1981-01-01

    This article deals with two questions, namely whether it is possible for black holes to exist, and if the answer is yes, whether we have found any yet. In deciding whether black holes can exist or not the central role in the shaping of our universe played by the forse of gravity is discussed, and in deciding whether we are likely to find black holes in the universe the author looks at the way stars evolve, as well as white dwarfs and neutron stars. He also discusses the problem how to detect a black hole, possible black holes, a southern black hole, massive black holes, as well as why black holes are studied

  7. The MaBwana Black men's study: community and belonging in the lives of African, Caribbean and other Black gay men in Toronto.

    Science.gov (United States)

    George, Clemon; Adam, Barry A; Read, Stanley E; Husbands, Winston C; Remis, Robert S; Makoroka, Lydia; Rourke, Sean B

    2012-01-01

    In Canada, there is a paucity of research aimed at understanding Black gay men and the antecedents to risk factors for HIV. This study is an attempt to move beyond risk factor analysis and explore the role of sexual and ethnic communities in the lives of these men. The study utilized a community-based research and critical race theory approach. Semi-structured interviews were conducted with eight key informants to augment our understanding of Black gay men and to facilitate recruitment of participants. In-depth interviews were done with 24 Black gay men. Our data showed that the construction of community for Black gay men is challenged by their social and cultural environment. However, these men use their resilience to navigate gay social networks. Black gay men expressed a sense of abjuration from both gay and Black communities because of homophobia and racism. It is essential for health and social programmers to understand how Black gay men interact with Black and gay communities and the complexities of their interactions in creating outreach educational, preventive and support services.

  8. Reconsidering the Freedom Charter, the black theology of liberation and the African proverb about the locust’s head in the context of poverty in South Africa

    Directory of Open Access Journals (Sweden)

    Ndikho Mtshiselwa

    2016-07-01

    Full Text Available While South Africa attained liberation from the apartheid rule in 1994, the legacy of colonialism and apartheid – in the form of poverty and economic inequality – continues to haunt black South Africans. The aim of this article is to make a case for the equitable sharing of South Africa’s mineral wealth amongst all its citizens with the view to alleviate poverty. Firstly, this article provides a reflection on the Freedom Charter and suggests that the values of the Charter, for instance, the sharing of resources and wealth, are relevant in South Africa today. Secondly, it is argued in the present article that the preferential option for the poor which is upheld in the black theology of liberation is equally relevant in post-apartheid South Africa where many black South Africans remain poor. Thirdly, this article argues that the African proverb, Bana ba motho ba ngwathelana hlogo ya tšie [The siblings share the head of a locust], also echoes the idea of equitable sharing of resources with a view to alleviate poverty. Lastly, the author submits that the idea of equitable sharing of resources and wealth that is echoed in the Freedom Charter, the black theology of liberation and the African wise saying support the equitable redistribution of the mineral wealth to the benefit of all South Africans.

  9. Does race matters in consumers' stated preferences for water and carbon footprints labelled food products? Insights from black and white South Africans

    Science.gov (United States)

    Owusu-Sekyere, Enoch; Jordaan, Henry

    2017-04-01

    In recent years, governments, policy-makers, and managers of private food companies and agribusinesses are interested in understanding how consumers will react to environmentally sustainable attributes and information on food product labels. This study examines consumers' stated preferences for water and carbon footprints labelled food products from the viewpoint of black and white South Africans. Discrete choice experimental data was collected from black and white consumers to possibly assess cross-ethnic variations in preferences for environmentally sustainable products. Two widely purchased livestock products were chosen for the choice experiment. We found that consumers' preferences for environmentally sustainable attributes vary significantly between black and white South Africans. Our findings revealed that there are profound heterogeneous consumer segments within black and white respondents. The heterogeneity within both sub-samples is better explained at the segment level, rather than at individual level. For both product categories, the findings revealed that there are more distinct consumer segments among black respondents, relative to white respondents. The black respondents consist of water sustainability advocates, carbon reduction advocates, keen environmentalist and environmental neutrals. The white respondents entail keen environmentalist, environmental cynics, and environmental neutrals. The inherent significant variations in preferences for environmentally sustainable attributes across segments and racial groups would help in formulating feasible, and segment-specific environmental sustainability policies and marketing strategies aimed at changing consumers' attitude towards environmentally sustainable products. Demographic targeting of consumer segments, sustainability awareness and segment-specific educational campaigns meant to enhance subjective and objective knowledge on environmental sustainability are important tools for food companies and

  10. Black silicon with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by mask-less reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Black bus-bars were realized by oxidized copper resulting in reflectance below 3% in the entire visible wavelength range. The combination of these two technologies may result in aesthetic, all-black panels based on conventional, front-contacted solar cells...

  11. Motivators and deterrents to blood donation among Black South Africans: a qualitative analysis of focus group data

    Science.gov (United States)

    Muthivhi, T. N.; Olmsted, M. G.; Park, H.; Sha, M.; Raju, V.; Mokoena, T.; Bloch, E. M.; Murphy, E. L.; Reddy, R.

    2015-01-01

    SUMMARY Background and Objectives South Africa has a markedly skewed representation where the majority of blood (62%) is presently collected from an ethnically White minority. This study seeks to identify culturally specific factors affecting motivation of donors in South Africa. Materials and Methods We performed a qualitative study to evaluate motivators and deterrents to blood donation among Black South Africans. A total of 13 focus groups, comprising a total of 97 Black South Africans, stratified by age and geographic location were conducted. Transcripts of the interviews were analysed using a coding framework by Bednall & Bove. Results Participants made 463 unique comments about motivators focusing primarily on promotional communications (28%), incentives (20%) and prosocial motivation (16%). Participants made 376 comments about deterrents which focused primarily on fear (41%), negative attitudes (14%) and lack of knowledge (10%). Conclusion Although prosocial motivation (altruism) was the most frequently mentioned individual motivator, promotional communication elicited more overall comments by participants. As reported by many authors, fear and lack of awareness were strong deterrents, but scepticism engendered by perceived racial discrimination in blood collection were unique to the South African environment. PMID:26104809

  12. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

    A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

  13. Do Cultural Attitudes Matter? The Role of Cultural Orientation on Academic Self-Concept among Black/African College Students

    Science.gov (United States)

    Williams, Wendi S.; Chung, Y. Barry

    2013-01-01

    The authors explored the relationship between academic self-concept and noncognitive variables (i.e., Africentric cultural orientation, academic class level, gender, and involvement in culturally relevant school and community activities) among Black/African college students. Results indicated that Africentric cultural orientation and academic…

  14. Perceptions and experiences of epilepsy among patients from black ethnic groups in South London.

    Science.gov (United States)

    Sonecha, Shaneil; Noble, Adam J; Morgan, Myfanwy; Ridsdale, Leone

    2015-09-01

    The National Institute of Clinical Excellence suggested black ethnic minorities with epilepsy have different cultural, communicative and health-care needs. However, little is known about these despite increasing migration of black African and Caribbean people to Europe. This study aims to explore perceptions and experiences of epilepsy among black African and Caribbean people in South London. Semi-structured interviews were undertaken with 11 participants, to examine their beliefs and perceptions of living with epilepsy. Interviews were recorded, transcribed, codes generated and thematic analysis undertaken. African participants described supernatural causes for epilepsy and experienced considerable stigma whereas Caribbean participants described epilepsy as a 'normal illness'. However, both African and Caribbean participants experienced social restrictions arising from their epilepsy. The findings of higher levels of perceived stigma and social restriction seen in African participants may be a continuation of beliefs reported in participants' country of origin. There is also evidence that views regarding epilepsy transition through generations vary depending on place of birth. Practical Implications Health-care professionals need to be aware of and engage with the particular beliefs and concerns of black African and Caribbean people to achieve equity in health outcomes.

  15. Personality and well-being in Black and White South African emerging adults

    Directory of Open Access Journals (Sweden)

    Jan Alewyn Nel

    2016-12-01

    Full Text Available Background In the last ten years, the South African Personality Inventory (SAPI has been developed as an indigenous measurement of personality for the multi-cultural environment of South Africa. The aim of the SAPI is to assess personality in an unbiased and equivalent way. For the purpose of this study, we used an 82-item version of the SAPI which measures nine factors (Conscientiousness, Emotional Stability, Extraversion, Facilitating, Integrity, Intellect, Openness, Relationship Harmony and Soft-heartedness. Participants and procedure A cross-sectional survey was conducted using the SAPI, the General Health Questionnaire and the Brief Multidimensional Student Life Satisfaction Scale. A purposive sample was drawn from Black and White emerging adults (N = 990. We assessed the relationship between personality aspects and well-being across groups in a multiple group structural equation model (SEM using the SPSS and AMOS programs. Results Black emerging adults showed evidence of more individualistic-inclined personality features, while the White emerging adults seem to demonstrate more collectivistic features. In terms of health, the White emerging adults experience more life satisfaction than their Black counterparts. Conscientiousness, emotional stability, extraversion, facilitating and openness predict well-being among emerging adults. Conclusions This study contributes to expanding the nomological network of the SAPI, and it enhances knowledge pertaining to the link between personality and well-being of emerging adults in South Africa. Understanding which factors contribute to poor mental health and lack of life satisfaction may lead to innovation programmes for emerging adults to assist them in dealing with negative health outcomes possibly associated with living in multicultural contexts.

  16. Black Curriculum Orientations: A Preliminary Inquiry.

    Science.gov (United States)

    Watkins, William H.

    1993-01-01

    Six curriculum orientations predominate in African-American educational experience: functionalism, accommodation, liberalism, Black Nationalism, Afrocentrism, and social reconstruction. Tied to the history of slavery and oppression, these orientations will continue to develop separate from the mainstream. (SK)

  17. THE LIVED EXPERIENCES OF BLACK AFRICAN MOTHERS FOLLOWING THE BIRTH OF A CHILD WITH DOWN SYNDROME: IMPLICATIONS FOR INDIGENISATION OF SOCIAL WORK

    Directory of Open Access Journals (Sweden)

    Mathebane, Mbazima

    2016-08-01

    Full Text Available The article discusses the lived experiences of black African mothers following the birth of a child with Down syndrome and implications of this for the indigenisation of social work practice in South Africa. A retrospective qualitative study following a phenomenological design was undertaken. Findings indicated that giving birth to a child with Down syndrome evokes intense psychological and social reactions from the mother, family and community. The cultural norms and values of black African people, including principles of ubuntu and their belief in collectivism, provide important opportunities, support systems and resources that could be pooled for efficient and effective helping intervention.

  18. Extended Family and Friendship Support Networks are both Protective and Risk Factors for Major Depressive Disorder, and Depressive Symptoms Among African Americans and Black Caribbeans

    Science.gov (United States)

    Taylor, Robert Joseph; Chae, David H.; Lincoln, Karen D.; Chatters, Linda M.

    2014-01-01

    This study explores relationships between lifetime and 12 month DSM-IV major depressive disorder (MDD), depressive symptoms and involvement with family and friends within a national sample of African American and Black Caribbean adults (n=5,191). MDD was assessed using the DSM-IV World Mental Health Composite International Diagnostic Interview (WMH-CIDI) and depressive symptoms were assessed using the CES-D and the K6. Findings indicated that among both populations close supportive ties with family members and friends are associated with lower rates of depression and major depressive disorder. For African Americans, closeness to family members was important for both 12 month and lifetime MDD; and both family and friend closeness were important for depressive symptoms. For Caribbean Blacks, family closeness had more limited associations with outcomes and was directly associated with psychological distress only. Negative interactions with family (conflict, criticisms), however, were associated with higher MDD and depressive symptoms among both African Americans and Black Caribbeans. PMID:25594791

  19. ‘My child did not like using sun protection’: practices and perceptions of child sun protection among rural black African mothers

    Directory of Open Access Journals (Sweden)

    Zamantimande Kunene

    2017-08-01

    Full Text Available Abstract Background Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. Methods To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child’s 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. They were then provided with sun protection equipment and advice. A follow-up questionnaire was administered two weeks later. Results Mothers reported that during the week prior to the baseline questionnaire, children spent on average less than 1 hour of time outdoors (most often spent in the shade. Most mothers (97% liked the sun protection equipment. However, many (78 of 86 reported that their child did not like any of the sun protection equipment and two-thirds stated that the sun protection equipment was not easy to use. Conclusions Among Black Africans in rural northern South Africa, we found a mismatch between parental preferences and child acceptance for using sun protection when outdoors. A better understanding of the health risks of incidental excess sun exposure and potential benefits of sun protection is required among Black Africans.

  20. Nutritional composition of the diets of South Asian, black African-Caribbean and white European children in the United Kingdom: the Child Heart and Health Study in England (CHASE).

    Science.gov (United States)

    Donin, A S; Nightingale, C M; Owen, C G; Rudnicka, A R; McNamara, M C; Prynne, C J; Stephen, A M; Cook, D G; Whincup, P H

    2010-07-01

    In the UK, South Asian adults have increased risks of CHD, type 2 diabetes and central obesity. Black African-Caribbeans, in contrast, have increased risks of type 2 diabetes and general obesity but lower CHD risk. There is growing evidence that these risk differences emerge in early life and that nutritional factors may be important. We have therefore examined the variations in nutritional composition of the diets of South Asian, black African-Caribbean and white European children, using 24 h recalls of dietary intake collected during a cross-sectional survey of cardiovascular health in eighty-five primary schools in London, Birmingham and Leicester. In all, 2209 children aged 9-10 years took part, including 558 of South Asian, 560 of black African-Caribbean and 543 of white European ethnicity. Compared with white Europeans, South Asian children reported higher mean total energy intake; their intakes of total fat, polyunsaturated fat and protein (both absolute and as proportions of total energy intake) were higher and their intakes of carbohydrate as a proportion of energy (particularly sugars), vitamin C and D, Ca and haem Fe were lower. These differences were especially marked for Bangladeshi children. Black African-Caribbean children had lower intakes of total and saturated fat (both absolute and as proportions of energy intake), NSP, vitamin D and Ca. The lower total and saturated fat intakes were particularly marked among black African children. Appreciable ethnic differences exist in the nutritional composition of children's diets, which may contribute to future differences in chronic disease risk.

  1. An Intersectional Social Capital Analysis of the Influence of Historically Black Sororities on African American Women's College Experiences at a Predominantly White Institution

    Science.gov (United States)

    Greyerbiehl, Lindsay; Mitchell, Donald, Jr.

    2014-01-01

    Research exploring the college experiences of African American women at predominantly White institutions (PWI) continues to be a necessity as African American women graduate at lower rates than their racial/ethnic peers. This qualitative study explored the influence historically Black sororities had on the college experiences of African American…

  2. Energetics of growth in semi-precocial shorebird chicks in a warm environment : The African black oystercatcher, Haematopus moquini

    NARCIS (Netherlands)

    Tjorve, Kathleen M. C.; Underhill, Les G.; Visser, G. Henk

    2007-01-01

    We studied prefledging growth, energy expenditure and time budgets of African Black Oystercatcher, Haematopus moquini, chicks on Robben Island, Western Cape, South Africa. The aim of the study was to investigate the effect of parental feeding on the growth and energetics of semi-precocial shorebird

  3. Black Alcoholism.

    Science.gov (United States)

    Watts, Thomas D.; Wright, Roosevelt

    1988-01-01

    Examines some aspects of the problem of alcoholism among Blacks, asserting that Black alcoholism can best be considered in an ecological, environmental, sociocultural, and public health context. Notes need for further research on alcoholism among Blacks and for action to reduce the problem of Black alcoholism. (NB)

  4. Understanding Afrocentrism: Why Blacks Dream of a World without Whites.

    Science.gov (United States)

    Early, Gerald

    1995-01-01

    Describes the perceived failure of integration and the growing number of black Americans who are looking at the world from an African perspective instead of from the European-centered perspective that dominates American culture. The article explains Afrocentrism's appeal in giving Blacks an ideological unity, not just on color but as an expression…

  5. Centrifugal washing and recovery as an improved method for obtaining lignin precipitated from South African kraft mill black liquor

    CSIR Research Space (South Africa)

    Namane, M

    2015-10-01

    Full Text Available This study describes centrifugal recovery as an improved method for collection of lignin isolated from black liquor obtained from a South African kraft mill. Precipitation of lignin was achieved by utilising 6 M sulphuric acid. Recovery...

  6. Retinal detachment in black South Africans

    African Journals Online (AJOL)

    low incidence of retinal detachment in black patients is not known. ... a retinal break. Predisposing factors include peripheral retinal degenerations, myopia, aphakia and trauma. Delay in presentation increases the difficulty in achieving adequate surgical ... On examination, note was taken of the visual acuity in both eyes, the ...

  7. Physical Activity Energy Expenditure and Sarcopenia in Black South African Urban Women.

    Science.gov (United States)

    Kruger, Herculina S; Havemann-Nel, Lize; Ravyse, Chrisna; Moss, Sarah J; Tieland, Michael

    2016-03-01

    Black women are believed to be genetically less predisposed to age-related sarcopenia. The objective of this study was to investigate lifestyle factors associated with sarcopenia in black South African (SA) urban women. In a cross-sectional study, 247 women (mean age 57 y) were randomly selected. Anthropometric and sociodemographic variables, dietary intakes, and physical activity were measured. Activity was also measured by combined accelerometery/heart rate monitoring (ActiHeart), and HIV status was tested. Dual energy x-ray absorptiometry was used to measure appendicular skeletal mass (ASM). Sarcopenia was defined according to a recently derived SA cutpoint of ASM index (ASM/height squared) decreasing to 8.1% after exclusion of participants who were HIV positive. In multiple regressions with ASM index, grip strength, and gait speed, respectively, as dependent variables, only activity energy expenditure (β = .27) was significantly associated with ASM index. Age (β = -.50) and activity energy expenditure (β = .17) were significantly associated with gait speed. Age (β = -.11) and lean mass (β = .21) were significantly associated with handgrip strength. Sarcopenia was prevalent among these SA women and was associated with low physical activity energy expenditure.

  8. Management of high blood pressure in Blacks: an update of the International Society on Hypertension in Blacks consensus statement.

    Science.gov (United States)

    Flack, John M; Sica, Domenic A; Bakris, George; Brown, Angela L; Ferdinand, Keith C; Grimm, Richard H; Hall, W Dallas; Jones, Wendell E; Kountz, David S; Lea, Janice P; Nasser, Samar; Nesbitt, Shawna D; Saunders, Elijah; Scisney-Matlock, Margaret; Jamerson, Kenneth A

    2010-11-01

    Since the first International Society on Hypertension in Blacks consensus statement on the "Management of High Blood Pressure in African American" in 2003, data from additional clinical trials have become available. We reviewed hypertension and cardiovascular disease prevention and treatment guidelines, pharmacological hypertension clinical end point trials, and blood pressure-lowering trials in blacks. Selected trials without significant black representation were considered. In this update, blacks with hypertension are divided into 2 risk strata, primary prevention, where elevated blood pressure without target organ damage, preclinical cardiovascular disease, or overt cardiovascular disease for whom blood pressure consistently secondary prevention, where elevated blood pressure with target organ damage, preclinical cardiovascular disease, and/or a history of cardiovascular disease, for whom blood pressure consistently blood pressure is ≤10 mm Hg above target levels, monotherapy with a diuretic or calcium channel blocker is preferred. When blood pressure is >15/10 mm Hg above target, 2-drug therapy is recommended, with either a calcium channel blocker plus a renin-angiotensin system blocker or, alternatively, in edematous and/or volume-overload states, with a thiazide diuretic plus a renin-angiotensin system blocker. Effective multidrug therapeutic combinations through 4 drugs are described. Comprehensive lifestyle modifications should be initiated in blacks when blood pressure is ≥115/75 mm Hg. The updated International Society on Hypertension in Blacks consensus statement on hypertension management in blacks lowers the minimum target blood pressure level for the lowest-risk blacks, emphasizes effective multidrug regimens, and de-emphasizes monotherapy.

  9. Substance Abuse Among Blacks Across the Diaspora.

    Science.gov (United States)

    Lacey, Krim K; Mouzon, Dawne M; Govia, Ishtar O; Matusko, Niki; Forsythe-Brown, Ivy; Abelson, Jamie M; Jackson, James S

    2016-07-28

    Lower rates of substance abuse are found among Black Americans compared to Whites, but little is known about differences in substance abuse across ethnic groups within the black population. We examined prevalence rates of substance abuse among Blacks across three geographic regions (US, Jamaica, Guyana). The study also sought to ascertain whether length of time, national context and major depressive episodes (MDE) were associated with substance abuse. We utilized three different data sources based upon probability samples collected in three different countries. The samples included 3,570 African Americans and 1,621 US Caribbean Black adults from the 2001-2003 National Survey of American Life (NSAL). An additional 1,142 Guyanese Blacks and 1,176 Jamaican Blacks living in the Caribbean region were included from the 2005 NSAL replication extension study, Family Connections Across Generations and Nations (FCGN). Mental disorders were based upon DSM-IV criteria. For the analysis, we used descriptive statistics, chi-square, and multivariate logistic regression analytic procedures. Prevalence of substance abuse varied by national context, with higher rates among Blacks within the United States compared to the Caribbean region. Rates of substance abuse were lower overall for women, but differ across cohorts by nativity and length of time in the United States, and in association with major depressive episode. The study highlights the need for further examination of how substance abuse disparities between US-based and Caribbean-based populations may become manifested.

  10. An investigation into the causes of absconding among black African ...

    African Journals Online (AJOL)

    breast cancer patients with regard to the choice of healer. Participants. 10 black ... family members to reveal a patient's place of residence. (An average of 30 black .... the biomedical approaches to cancer treatment were viewed with suspicion .... treatments said that their therapy management groups had decided that they ...

  11. Black holes

    OpenAIRE

    Brügmann, B.; Ghez, A. M.; Greiner, J.

    2001-01-01

    Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries.

  12. A Hermeneutic Phenomenological Study of the Experiences of Female African American Undergraduate Engineering Students at a Predominantly White and an Historically Black Institution

    Science.gov (United States)

    Frillman, Sharron Ann

    2011-01-01

    This phenomenological study examined the experiences of twelve female African Americans enrolled as fulltime undergraduate engineering students at North Carolina Agricultural and Technical State University, an historically Black university, and seven female African Americans enrolled as undergraduate engineering students at Purdue University in…

  13. The phase structure of higher-dimensional black rings and black holes

    International Nuclear Information System (INIS)

    Emparan, Roberto; Harmark, Troels; Niarchos, Vasilis; Obers, Niels A.; RodrIguez, Maria J.

    2007-01-01

    We construct an approximate solution for an asymptotically flat, neutral, thin rotating black ring in any dimension D ≥ 5 by matching the near-horizon solution for a bent boosted black string, to a linearized gravity solution away from the horizon. The rotating black ring solution has a regular horizon of topology S 1 x S D-3 and incorporates the balancing condition of the ring as a zero-tension condition. For D = 5 our method reproduces the thin ring limit of the exact black ring solution. For D ≥ 6 we show that the black ring has a higher entropy than the Myers-Perry black hole in the ultra-spinning regime. By exploiting the correspondence between ultra-spinning black holes and black membranes on a two-torus, we take steps towards qualitatively completing the phase diagram of rotating blackfolds with a single angular momentum. We are led to propose a connection between MP black holes and black rings, and between MP black holes and black Saturns, through merger transitions involving two kinds of 'pinched' black holes. More generally, the analogy suggests an infinite number of pinched black holes of spherical topology leading to a complicated pattern of connections and mergers between phases

  14. On the Charter Question: Black Marxism and Black Nationalism

    Science.gov (United States)

    Stern, Mark; Hussain, Khuram

    2015-01-01

    This article brings two black intellectual traditions to bear on the question of charter schools: black Marxism and black nationalism. The authors examine the theoretical and rhetorical devices used to talk about charters schools by focusing on how notions of "black liberation" are deployed by the charter movement, and to what end. The…

  15. "Be Real Black for Me": Imagining BlackCrit in Education

    Science.gov (United States)

    Dumas, Michael J.; ross, kihana miraya

    2016-01-01

    The authors put forward a theorization of a Black Critical Theory, or what might be called BlackCrit, within, and in response to, Critical Race Theory, and then outline ways that BlackCrit in education helps us to more incisively analyze how the specificity of (anti)blackness matters in explaining how Black bodies become marginalized, disregarded,…

  16. Black American Literature and the Problem of Racism, Slavery and ...

    African Journals Online (AJOL)

    The problem created by racism could be traced to be the major factor behind most Black literature through the ages. In America, this gave rise to a new form of literary expression known as the Black American Literature or African American Literature. The main concern of this sub-genre of literature is to redeem the face of ...

  17. Black hole astrophysics

    International Nuclear Information System (INIS)

    Blandford, R.D.; Thorne, K.S.

    1979-01-01

    Following an introductory section, the subject is discussed under the headings: on the character of research in black hole astrophysics; isolated holes produced by collapse of normal stars; black holes in binary systems; black holes in globular clusters; black holes in quasars and active galactic nuclei; primordial black holes; concluding remarks on the present state of research in black hole astrophysics. (U.K.)

  18. Optic Nerve Head and Retinal Nerve Fiber Layer Differences Between Caribbean Black and African American Patients as Measured by Spectral Domain OCT.

    Science.gov (United States)

    Rao, Rohini; Dhrami-Gavazi, Elona; Al-Aswad, Lama; Ciarleglio, Adam; Cioffi, George A; Blumberg, Dana M

    2015-01-01

    There are well-established differences in optic nerve morphology between patients of African and European descent. Spectral domain optical coherence tomography (OCT) scanning has demonstrated these differences with respect to optic disc area (DA), average cup-disc ratio, cup volume, and nerve fiber layer thickness. However, the term "African descent" describes a heterogenous group with considerable variability. This study evaluates differences in optic nerve and retinal nerve fiber layer (RNFL) parameters as measured by Cirrus HD-OCT between Caribbean black and African American patients. A total of 25 African American subjects and 25 Caribbean black subjects with normal ocular examinations were consecutively recruited to this study. All patients received imaging of the optic nerve and nerve fiber layer with Cirrus HD-OCT. Optic nerve and RNFL parameters were evaluated for statistically significant differences using a t test. A mixed effect model for correlated data was then created to adjust outcome variables for (1) repeated measures and (2) optic nerve size. Two one-sided t tests were then utilized to determine equivalence. After adjustment for DA, RNFL thickness, cup volume, DA, inferior nerve fiber layer, and vertical cup-disc ratio demonstrated statistically significant equivalence between the 2 groups (P value fiber layer quadrant was significantly different between the 2 groups and may merit further investigation. Findings of this study suggest that optic nerve and RNFL morphology is markedly similar between Caribbean blacks and African Americans once adjusted for optic nerve size but cannot be considered equivalent in all measures, particularly in the superior nerve fiber layer.

  19. Coping and metabolic syndrome indicators in urban black South African men: the SABPA study.

    Science.gov (United States)

    du Plessis, A; Malan, L; Malan, N T

    2010-01-01

    Urbanisation is associated with obesity, hypertension and development of the metabolic syndrome (MS). We aimed to assess the use of different coping styles and their influence on increases in MS indicators and target end-organ damage (TOD) in urban black African men. A sample of 53 men was classified as clear high active (AC, n = 30) or passive coping (PC, n = 23) responders, using the Amirkhan African validated coping style indicator. Blood pressure (BP) was recorded with an aneroid sphygmomanometer and waist circumference (WC) was determined. Carotid intima-media thickness (CIMT) and microalbuminuria were analysed to determine TOD. Fasting serum and eight-hour urine samples revealed elevated MS indicators in AC men. Strong associations existed between MS indicators and TOD in AC but not PC men. To conclude, only BP and seeking social support were positively associated with TOD in urban PC African men, while in urban AC African men, most MS indicators were positively associated with TOD, i.e. sub-clinical atherosclerosis and renal impairment.

  20. White theology in dialogue with Black Theology: Exploring the ...

    African Journals Online (AJOL)

    2016-05-30

    May 30, 2016 ... later work, as a particular white response to Black Theology. To put it in ... things that actually control the lives of people, in other words, the real “gods” ...... Ethics that matters: African, Caribbean, and African American sources ...

  1. Empowering Young Black Males--III: A Systematic Modular Training Program for Black Male Children & Adolescents.

    Science.gov (United States)

    Lee, Courtland C.

    This series of five interrelated modules is an update and revision of "Saving the Native Son: Empowerment Strategies for Young Black Males (1996)." It offers specific strategies for empowering young African American males to help them achieve optimal educational and social success. Empowerment is a developmental process by which people who are…

  2. Obesity Status and Body Satisfaction: Are There Differences between African American College Females at Black and White Universities?

    Science.gov (United States)

    James, Delores C. S.; Bonds, Jennifer R.

    2006-01-01

    The goals of this project were to 1) assess obesity status and body satisfaction among African American college students, and 2) to compare differences in these variables between students at a predominantly white university (PWU) and a historically black college and university (HBCU). Four hundred and two undergraduate females completed a…

  3. Gender Trouble and the Tragic Black Woman Hybrids in Clotel, Quicksand and Passing

    Directory of Open Access Journals (Sweden)

    Hayder Naji Shanbooj Alolaiwi

    2017-05-01

    Full Text Available The African-American female character's description in Clotel, Quicksand and Passing are very impressive, among whom Clotel, Clare and Irene are depicted as one of the most important “passing” figures for the whole story. Though sharing some similarities with the traditional Black women in the past African-American novels, Clotel, Clare and Irene are very different. The strong connection with as well as variations than the usual gender pattern are mixed within these women. It is only by this new approach that the reader can re-think Black woman and build a new African-American female identity. Taking into the consideration an ecofeminist point of view, this paper is going to study the points of similarities with and differences from the traditional Black Women in the novel, unwrap on the developing subject identity of Black women in this novel, in order to prove that in this novel female subject identity is more than a true representation of essentialism and dualism, in a special and unique realistic perspective.

  4. Contemporary Black Theatre.

    Science.gov (United States)

    Thomas, Pearl

    The distinguishable black theatre in America, mirroring a distinguishable black experience, is an artistic product which demands audience involvement. Both the Afro-American oral tradition and the art of gesture are integral aspects of black theatre. In addition, the tragedy found black theatre is not tragedy in the classic sense, as blacks feel…

  5. Educational Lynching: Critical Race Theory and the Suspension of Black Boys

    Science.gov (United States)

    Payne, Macheo

    2010-01-01

    Looking at the disproportionate suspension of African American, Black male students through the lens of critical race theory, this presents arguments from a CRT how the disproportionate suspension of Black male students is rooted in white supremacy and racist policy in the United States. Local recommendations are offered for Oakland Unified School…

  6. Caged black holes: Black holes in compactified spacetimes. I. Theory

    International Nuclear Information System (INIS)

    Kol, Barak; Sorkin, Evgeny; Piran, Tsvi

    2004-01-01

    In backgrounds with compact dimensions there may exist several phases of black objects including a black hole and a black string. The phase transition between them raises questions and touches on fundamental issues such as topology change, uniqueness, and cosmic censorship. No analytic solution is known for the black hole, and moreover one can expect approximate solutions only for very small black holes, while phase transition physics happens when the black hole is large. Hence we turn to numerical solutions. Here some theoretical background to the numerical analysis is given, while the results will appear in a subsequent paper. The goals for a numerical analysis are set. The scalar charge and tension along the compact dimension are defined and used as improved order parameters which put both the black hole and the black string at finite values on the phase diagram. The predictions for small black holes are presented. The differential and the integrated forms of the first law are derived, and the latter (Smarr's formula) can be used to estimate the 'overall numerical error'. Field asymptotics and expressions for physical quantities in terms of the numerical values are supplied. The techniques include the 'method of equivalent charges', free energy, dimensional reduction, and analytic perturbation for small black holes

  7. Primary black holes

    International Nuclear Information System (INIS)

    Novikov, I.; Polnarev, A.

    1981-01-01

    Proves are searched for of the formation of the so-called primary black holes at the very origin of the universe. The black holes would weigh less than 10 13 kg. The formation of a primary black hole is conditional on strong fluctuations of the gravitational field corresponding roughly to a half of the fluctuation maximally permissible by the general relativity theory. Only big fluctuations of the gravitational field can overcome the forces of the hot gas pressure and compress the originally expanding matter into a black hole. Low-mass black holes have a temperature exceeding that of the black holes formed from stars. A quantum process of particle formation, the so-called evaporation takes place in the strong gravitational field of a black hole. The lower the mass of the black hole, the shorter the evaporation time. The analyses of processes taking place during the evaporation of low-mass primary black holes show that only a very small proportion of the total mass of the matter in the universe could turn into primary black holes. (M.D.)

  8. Blackness: faith, culture, ideology and discourse*

    African Journals Online (AJOL)

    Crowther, West Africa's first black bishop, who grovelled before his white missionary .... African-American profane discourse is the Signifying Monkey, then "Tar Baby is as ... racism and sexism, systems described by Christian as "societal and psychological... ..... When the inner conflict and tension occasioned by culture theo-.

  9. Black women’s ‘two-ness’ in african-american literature: can black and white worlds join together? = A dualidade de mulheres negras na literatura afro-americana: os mundos negro e branco podem se unir?

    Directory of Open Access Journals (Sweden)

    José Endoença Martins

    2010-01-01

    Full Text Available The article discusses how black women keep contacts with both black and white worlds in novels written by African-American female writers. In Toni Morrison’s (1970 The Bluest Eye, Pecola Breedlove keeps contact with the white world through her assimilationist behavior; in Alice Walker’s (1982 The Color Purple, Celie freezes herself in the black world by playing the role of the nationalist Negro; finally, in Lorraine Hansberry’s (1987 A Raisin in the Sun, Mama Younger joins black and white worlds together when she develops a catalyst agenda, as she moves to a white neighborhood.O artigo discute como mulheres negras mantêm contato com os mundos negro e branco em romances de escritoras afroamericanas. Em O Olho Mais Azul, de Toni Morrison (1970, Pecola Breedlove se alia ao mundo branco pelo comportamento assimilacionista; em A Cor Púrpura, de Alice Walker (1982, Celie se isola no mundo negro ao assumir o papel do Negro nacionalista; por fim, em Uma Cereja ao Sol, de Lorraine Hansberry (1987, Mama Younger aproxima o mundo negro e branco quando se torna catalista, indo morar num bairro branco.

  10. 77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

    Science.gov (United States)

    2012-11-26

    ... Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of..., 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor) and Black Bear Development Holdings, LLC and Black Bear SO, LLC (transferees) filed an application for the partial the transfer of licenses...

  11. Racial and Athletic Identity of African American Football Players at Historically Black Colleges and Universities and Predominantly White Institutions

    Science.gov (United States)

    Steinfeldt, Jesse A.; Reed, Courtney; Steinfeldt, M. Clint

    2010-01-01

    This study examined racial and athletic identity among African American football players at historically Black colleges and universities (HBCUs) and predominantly White institutions (PWIs). Negotiating the dualism of racial and athletic identities can be problematic because both roles are subject to prejudice and discrimination, particularly for…

  12. Phase transition for black holes with scalar hair and topological black holes

    International Nuclear Information System (INIS)

    Myung, Yun Soo

    2008-01-01

    We study phase transitions between black holes with scalar hair and topological black holes in asymptotically anti-de Sitter spacetimes. As the ground state solutions, we introduce the non-rotating BTZ black hole in three dimensions and topological black hole with hyperbolic horizon in four dimensions. For the temperature matching only, we show that the phase transition between black hole with scalar hair (Martinez-Troncoso-Zanelli black hole) and topological black hole is second-order by using differences between two free energies. However, we do not identify what order of the phase transition between scalar and non-rotating BTZ black holes occurs in three dimensions, although there exists a possible decay of scalar black hole to non-rotating BTZ black hole

  13. Carcinogenic nitrosamines in traditional beer as the cause of oesophageal squamous cell carcinoma in black South Africans.

    Science.gov (United States)

    Pillay, Viness; Isaacson, Charles; Mothobi, Pride; Hale, Martin; Tomar, Lomas Kumar; Tyagi, Charu; Altini, Mario; Choonara, Yahya Essop; Kumar, Pradeep

    2015-09-21

    Before the 1930s, squamous cell carcinoma (SCC) of the oesophagus was almost unknown among black South Africans. From the 1930s the annual frequency rose. A dietary cause was sought, the staple diet of black people having changed from sorghum to maize (corn), with traditional beer being brewed from maize. Carcinogenic N-nitrosamines in traditional beer were suggested as a cause of SCC of the oesophagus, with Fusarium moniliforme, a corn saprophyte, thought to play a role. To confirm the presence of N-nitrosamines in traditional beer and demonstrate a mechanism for the oncogenesis of oesophageal carcinoma. Analysis by high-performance liquid chromatography was conducted for the identification of nitrosamines in traditional beer samples, and molecular docking studies were employed to predict the affinity between N-nitrosamines and the S100A2 protein. Carcinogenic N-nitrosamines were identified in all six samples of traditional beer examined (N=18 analyses), and docking studies confirmed a high affinity of the nitrosamine N-nitrosopyrrolidone with the S100A2 protein. This may result in the altered expression of the S100A2 protein, leading to tumour progression and prognosis. It is suggested that carcinogenic N-nitrosamines in traditional beer are a major factor in the causation of SCC of the oesophagus in black South Africans. N-nitrosamines have been shown to produce cancer experimentally, but there has not been conclusive epidemiological evidence that N-nitrosamines are carcinogenic to humans. This study is the first to demonstrate the potential link between N-nitrosamines and a human tumour.

  14. From binary black hole simulation to triple black hole simulation

    International Nuclear Information System (INIS)

    Bai Shan; Cao Zhoujian; Han, Wen-Biao; Lin, Chun-Yu; Yo, Hwei-Jang; Yu, Jui-Ping

    2011-01-01

    Black hole systems are among the most promising sources for a gravitational wave detection project. Now, China is planning to construct a space-based laser interferometric detector as a follow-on mission of LISA in the near future. Aiming to provide some theoretical support to this detection project on the numerical relativity side, we focus on black hole systems simulation in this work. Considering the globular galaxy, multiple black hole systems also likely to exist in our universe and play a role as a source for the gravitational wave detector we are considering. We will give a progress report in this paper on our black hole system simulation. More specifically, we will present triple black hole simulation together with binary black hole simulation. On triple black hole simulations, one novel perturbational method is proposed.

  15. The evaluation of service delivery in the fast growing black diamond market / R. Venter

    OpenAIRE

    Venter, Raymano

    2010-01-01

    The black middle–class market segment also known as the black diamond market segment has shown immense growth in SA. It currently consists of approximately 3 million black middle–class South Africans with a buying power of approximately R200 billion. Despite the immense size and spending power of black diamonds, combined with its rapid growth over the past 15 years and expected future growth, little research has been conducted on this market segment. The rapid market growth ...

  16. Surface geometry of 5D black holes and black rings

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Goswami, Rituparno

    2007-01-01

    We discuss geometrical properties of the horizon surface of five-dimensional rotating black holes and black rings. Geometrical invariants characterizing these 3D geometries are calculated. We obtain a global embedding of the 5D rotating black horizon surface into a flat space. We also describe the Kaluza-Klein reduction of the black ring solution (along the direction of its rotation) which, though it is nakedly singular, relates this solution to the 4D metric of a static black hole distorted by the presence of external scalar (dilaton) and vector ('electromagnetic') fields. The properties of the reduced black hole horizon and its embedding in E 3 are briefly discussed

  17. Black Holes

    OpenAIRE

    Townsend, P. K.

    1997-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usu...

  18. Black silicon solar cells with black bus-bar strings

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io

    2016-01-01

    We present the combination of black silicon texturing and blackened bus-bar strings as a potential method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon was realized by maskless reactive ion etching resulting in total, average reflectance...... below 0.5% across a 156x156 mm2 silicon wafer. Four different methods to obtain blackened bus-bar strings were compared with respect to reflectance, and two of these methods (i.e., oxidized copper and etched solder) were used to fabricate functional allblack solar 9-cell panels. The black bus-bars (e.......g., by oxidized copper) have a reflectance below 3% in the entire visible wavelength range. The combination of black silicon cells and blackened bus-bars results in aesthetic, all-black panels based on conventional, front-contacted solar cells without compromising efficiency....

  19. 'I'm Black and I'm Proud': A Majority Ecological Context Protects Affective Aspects of Black Identity Under Stereotype Threat.

    Science.gov (United States)

    Oliver, Andre'; Andemeskel, Ghilamichael; King, Carlise R; Wallace, Lyndsey; McDougal, Serie; Monteiro, Kenneth P; Ben-Zeev, Avi

    2017-12-01

    We provide evidence that stereotype threat, a phenomenon that causes stigmatized individuals to experience group-based evaluative concerns (Steele in Am Psychol 52:613-629, 1997; Whistling Vivaldi and other clues to how stereotypes affect us, W.W. Norton, New York, 2010), impacts affective aspects of Black identity as a function of majority versus minority ecological contexts. Black/African-American students, enrolled in either Africana Studies (Black ecological majority) or Psychology (Black ecological minority), completed private and public regard subscales from the Multidimensional Inventory of Black Identity (Sellers et al. in Pers Soc Psychol Rev 2:18-39, 1998) at baseline (Time 1) and after being randomly assigned to a stereotype threat or no-threat/control condition (Time 2). In threat, participants were introduced to a 'puzzle' task as diagnostic of intellectual abilities, whereas in no-threat the same task was introduced as culture fair, such that people from different racial/ethnic groups had performed similarly on this task in the past. In Psychology, students under threat exhibited a simultaneous decrease and increase in private and public regard, respectively, a pattern shown in the literature to be associated with discrimination-based distress and lesser well-being in Black ecological minority environments. In contrast, Africana Studies students' racial identity under threat remained intact. We discuss the protective effects of Africana Studies on racial identity and implications for educational reform.

  20. Alcohol and tobacco advertising in black and general audience newspapers: targeting with message cues?

    Science.gov (United States)

    Cohen, Elisia L; Caburnay, Charlene A; Rodgers, Shelly

    2011-07-01

    This study content analyzed 928 tobacco- and alcohol-related advertisements from a 3-year national sample of Black (n = 24) and general audience (n = 11) newspapers from 24 U.S. cities. The authors compared the frequency of tobacco and alcohol product and control advertising in Black versus general audience newspapers, as well as the presence of 5 message cues: model ethnicity, presence of health official, referral to resources, personal behavior mobilization, and localization. Results within health issues show that Black newspapers had more alcohol product advertising than did general audience newspapers. In contrast, Black newspapers had less alcohol and tobacco control advertising than general audience newspapers. Black newspapers' tobacco/alcohol product advertisements had more African American models than did general audience newspapers' tobacco/alcohol advertising, whereas general audience newspapers' tobacco control advertisements were significantly more likely to feature public health officials than ads in Black newspapers. Fewer message cues such as personal behavior mobilization, referral to resources, and localization were present in Black versus general audience newspapers. Results suggest that Black newspapers may have greater dependency than do general audience newspapers on these risk-related advertisements that target African American consumers. Given the current advertising environment, public health initiatives are needed to counter unhealthy alcohol product advertising messages that target vulnerable populations.

  1. Keloids: Assessment of effects and psychosocial- impacts on subjects in a black African population

    Directory of Open Access Journals (Sweden)

    Olaitan P

    2009-01-01

    Full Text Available Background: Keloids are vexatious swelling on the skin or the conjuctiva. The effects and impacts of these lesions have not been assessed in a keloid endemic environment like Nigeria. Aims: The purpose of this study is to assess the psychosocial impact as well as effects of keloids on the subjects in a black African population where lesions are commonly seen. Methods: This is a prospective study which assesses the impacts of keloid on keloid patients. Consented patients who presented to the Plastic Surgery Clinic of the Lautech Teaching Hospital, Osogbo, Nigeria were recruited into the study. A set of questionnaires were administered to all consented patients. The administered questionnaires were analyzed using SPSS version 10. Results: One hundred and thirty one patients were involved in this study. They comprised of 61 males and 70 females. Most (96.8% of them had the keloid lesion for more than one year. Sixteen (12.2% of the patients felt that keloids negatively affect their works, 64 (48.9% of the patients felt stigmatized by keloids, 28 (56.0% of them who had lesions in conspicuous parts while 24 (46.2% had lesions in non-conspicuous parts. Females (59.1% felt stigmatized than males. Only 47 (35.8% of the patients believed that keloid swelling limit their social interaction. Conclusion: Keloids do not appear to have significant negative impacts on keloid patients in a keloid-endemic community like a black African population.

  2. Discrimination Increases Suicidal Ideation in Black Adolescents Regardless of Ethnicity and Gender

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2017-11-01

    Full Text Available Background: Discrimination is a common experience for Blacks across various developmental periods. Although much is known about the effect of discrimination on suicidal ideation of adults, less is known about the same association in Black youth. Aim: We examined the association between discrimination and suicidal ideation in a national sample of Black youth. We also explored gender and ethnic differences in this association. Methods: We used data from the National Survey of American Life-Adolescents (NSAL-A, 2003–2004. In total, 1170 Black adolescents entered the study. This number was composed of 810 African American and 360 Caribbean Black youth (aged 13 to 17 years. Demographic and socioeconomic factors were controls, perceived discrimination was the predictor, and lifetime suicidal ideation was the outcome. Logistic regression was used to test the association between perceived discrimination and suicidal ideation in the pooled sample, as well as based on ethnicity and gender. Results: In the pooled sample of Black youth, higher perceived discrimination was associated with higher odds of suicidal ideation (Odds Ratio (OR = 1.09; 95% Confidence Interval (CI = 1.02−1.17. This association was significant net of age, ethnicity, gender, and socioeconomic status. We did not find interactions between perceived discrimination and ethnicity or gender on suicidal ideation. Perceived discrimination was associated with suicidal ideation in African Americans (CI = 1.09; 95% CI = 1.01−1.17 and Caribbean Blacks (CI = 1.16; 95% CI = 1.03−1.32, males (CI = 1.11; 95% CI = 1.00−1.25, and females (CI = 1.08; 95% CI = 1.00−1.16. Conclusion: Discrimination jeopardizes the mental health of Black youth. In a universal pattern, discrimination is associated with suicidal ideation in Black youth. More research is needed on this topic.

  3. Discrimination Increases Suicidal Ideation in Black Adolescents Regardless of Ethnicity and Gender.

    Science.gov (United States)

    Assari, Shervin; Moghani Lankarani, Maryam; Caldwell, Cleopatra Howard

    2017-11-06

    Discrimination is a common experience for Blacks across various developmental periods. Although much is known about the effect of discrimination on suicidal ideation of adults, less is known about the same association in Black youth. We examined the association between discrimination and suicidal ideation in a national sample of Black youth. We also explored gender and ethnic differences in this association. We used data from the National Survey of American Life-Adolescents (NSAL-A), 2003-2004. In total, 1170 Black adolescents entered the study. This number was composed of 810 African American and 360 Caribbean Black youth (aged 13 to 17 years). Demographic and socioeconomic factors were controls, perceived discrimination was the predictor, and lifetime suicidal ideation was the outcome. Logistic regression was used to test the association between perceived discrimination and suicidal ideation in the pooled sample, as well as based on ethnicity and gender. In the pooled sample of Black youth, higher perceived discrimination was associated with higher odds of suicidal ideation (Odds Ratio (OR) = 1.09; 95% Confidence Interval (CI) = 1.02-1.17). This association was significant net of age, ethnicity, gender, and socioeconomic status. We did not find interactions between perceived discrimination and ethnicity or gender on suicidal ideation. Perceived discrimination was associated with suicidal ideation in African Americans (CI = 1.09; 95% CI = 1.01-1.17) and Caribbean Blacks (CI = 1.16; 95% CI = 1.03-1.32), males (CI = 1.11; 95% CI = 1.00-1.25), and females (CI = 1.08; 95% CI = 1.00-1.16). Discrimination jeopardizes the mental health of Black youth. In a universal pattern, discrimination is associated with suicidal ideation in Black youth. More research is needed on this topic.

  4. Distortion of Schwarzschild-anti-de Sitter black holes to black strings

    International Nuclear Information System (INIS)

    Tomimatsu, Akira

    2005-01-01

    Motivated by the existence of black holes with various topologies in four-dimensional spacetimes with a negative cosmological constant, we study axisymmetric static solutions describing any large distortions of Schwarzschild-anti-de Sitter black holes parametrized by the mass m. Under the approximation such that m is much larger than the anti-de Sitter radius, it is found that a cylindrically symmetric black string is obtained as a special limit of distorted spherical black holes. Such a prolonged distortion of the event horizon connecting a Schwarzschild-anti-de Sitter black hole to a black string is allowed without violating both the usual black hole thermodynamics and the hoop conjecture for the horizon circumference

  5. Black churches and HIV/AIDS: factors influencing congregations’ responsiveness to social issues.

    Science.gov (United States)

    Fulton, Brad R

    2011-01-01

    The ambivalent response of many black churches to current social issues has caused some scholars to question the centrality of black churches within African-American communities. Using a nationally representative sample of black congregations, this study engages the debate about the institutional centrality of black churches by focusing on their response to HIV/AIDS. Although many congregational studies treat black churches as a monolithic whole, this analysis identifies heterogeneity among black churches that shapes their responsiveness to social issues. Contrary to prior claims, a congregation's liberal-conservative ideological orientation does not significantly affect its likelihood of having an HIV/AIDS program. Beyond assessing churches’ internal characteristics, this study uses institutional theory to analyze churches as open systems that can be influenced by their surrounding environment. It demonstrates that externally engaged congregations are significantly more likely to have a program. These results indicate that black churches maintain institutional centrality by engaging their external environment.

  6. A twentieth-century triangle trade: selling black beauty at home and abroad, 1945–1965.

    Science.gov (United States)

    McAndrew, Malia

    2010-01-01

    This study examines the careers of African American beauty culturists as they worked in the United States, Europe, and Africa between 1945 and 1965. Facing push back at home, African American beauty entrepreneurs frequently sought out international venues that were hospitable and receptive to black Americans in the years following World War II. By strategically using European sites that white Americans regarded as the birthplace of Western fashion and beauty, African American entrepreneurs in the fields of modeling, fashion design, and hair care were able to win accolades and advance their careers. In gaining support abroad, particularly in Europe, these beauty culturists capitalized on their international success to establish, legitimize, and promote their business ventures in the United States. After importing a positive reputation for themselves from Europe to the United States, African American beauty entrepreneurs then exported an image of themselves as the world's premier authorities on black beauty to people of color around the globe as they sold their products and marketed their expertise on the African continent itself. This essay demonstrates the important role that these black female beauty culturists played, both as businesspeople and as race leaders, in their generation's struggle to gain greater respect and opportunity for African Americans both at home and abroad. In doing so it places African American beauty culturists within the framework of transatlantic trade networks, the Black Freedom Movement, Pan-Africanism, and America's Cold War struggle.

  7. Low-mass black holes as the remnants of primordial black hole formation.

    Science.gov (United States)

    Greene, Jenny E

    2012-01-01

    Bridging the gap between the approximately ten solar mass 'stellar mass' black holes and the 'supermassive' black holes of millions to billions of solar masses are the elusive 'intermediate-mass' black holes. Their discovery is key to understanding whether supermassive black holes can grow from stellar-mass black holes or whether a more exotic process accelerated their growth soon after the Big Bang. Currently, tentative evidence suggests that the progenitors of supermassive black holes were formed as ∼10(4)-10(5) M(⊙) black holes via the direct collapse of gas. Ongoing searches for intermediate-mass black holes at galaxy centres will help shed light on this formation mechanism.

  8. Investigating Black ASL: A Systematic Review

    Science.gov (United States)

    Toliver-Smith, Andrea; Gentry, Betholyn

    2017-01-01

    The authors reviewed the literature regarding linguistic variations seen in American Sign Language. These variations are influenced by region and culture. Features of spoken languages have also influenced sign languages as they intersected, e.g., Black ASL has been influenced by African American English. A literature review was conducted to…

  9. Factors Leading African Americans and Black Caribbeans to Use Social Work Services for Treating Mental and Substance Use Disorders

    Science.gov (United States)

    Cheng, Tyrone C.; Robinson, Michael A.

    2013-01-01

    This secondary analysis of 5,000 African Americans and black Caribbeans explored how their use of social work services to address mental and substance use disorders was associated with the disorder involved as well as their perceived need for services, belief system, family resources, proximity to services, social-structural factors, and…

  10. Harriet Powers: Portrait of a Black Quilter.

    Science.gov (United States)

    Frye, Gladys-Marie

    1987-01-01

    Discusses the following aspects of the life and art of Harriet Powers (born 1837), a Black quilter from Georgia: (1) subject matter of quilts; (2) African continuity; (3) provenance of quilts; (4) Powers' personal history; and (5) historical context of quilts. (BJV)

  11. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life.

  12. Magnetized black holes and black rings in the higher dimensional dilaton gravity

    International Nuclear Information System (INIS)

    Yazadjiev, Stoytcho S.

    2006-01-01

    In this paper we consider magnetized black holes and black rings in the higher dimensional dilaton gravity. Our study is based on exact solutions generated by applying a Harrison transformation to known asymptotically flat black hole and black ring solutions in higher dimensional spacetimes. The explicit solutions include the magnetized version of the higher dimensional Schwarzschild-Tangherlini black holes, Myers-Perry black holes, and five-dimensional (dipole) black rings. The basic physical quantities of the magnetized objects are calculated. We also discuss some properties of the solutions and their thermodynamics. The ultrarelativistic limits of the magnetized solutions are briefly discussed and an explicit example is given for the D-dimensional magnetized Schwarzschild-Tangherlini black holes

  13. Picture Books about Blacks: An Interview with Opal Moore.

    Science.gov (United States)

    MacCann, Donnarae; Richard, Olga

    1991-01-01

    Presents an interview with Opal Moore, who discusses Black imagery in picture books published in the last four years and the institutions that circulate that imagery. Topics discussed include the issue of race pride; interracial themes; appropriate illustrations; African versus African-American books; and the roles of publishers, books reviewers,…

  14. Cloacolithiasis and intestinal lymphosarcoma in an African black-footed penguin (Spheniscus demersus).

    Science.gov (United States)

    Jones, Krista L; Field, Cara L; Stedman, Nancy L; MacLean, Robert A

    2014-06-01

    A 13-yr-old male African black-footed penguin (Spheniscus demersus) presented thrice over 7 mo with gastrointestinal obstruction secondary to cloacolithiasis. Clinical signs consistently resolved with cloacolith removal and supportive care. However, 10 mo after initial presentation, it presented with similar signs, plus significant weight loss. No cloacolith was found, and it subsequently died. Significant gross findings included bilateral cecal masses, colonic perforation, and marked secondary coelomitis, multifocal tan to pale hepatic nodules, and pale kidneys with miliary white foci. Histopathologic diagnoses were intestinal lymphosarcoma with hepatic and renal metastases, secondary intestinal rupture, and subacute severe bacterial coelomitis. To the authors' knowledge, this is the first full report of either cloacolithiasis or lymphosarcoma in a penguin.

  15. Predictors of success for african black physiotherapy students in South Africa

    Directory of Open Access Journals (Sweden)

    N. Mbambo-Kekana

    2011-01-01

    Full Text Available high school performance and aptitude tests are usually used to predict success at university, but this may not be applicable when the ethnic group of the student is considered. The aim of this study was to investigate factors  that  predict  success  of  African  black  students  in  physiotherapy programmes and whether these factors are influenced by race. A mixed methods approach was used. one hundred and twenty eight graduates who graduated between 2000 and 2005 from eight universities in South Africa and six heads of Physiotherapy Departments participated in the research. A  postal  questionnaire  comprising  closed  and  open-ended questions was used  for  graduate  and  in-depth  interviews  were conducted  with  heads  of Departments. Quantitative data were analyzed using descriptive analysis as well as inferential statistics using Chi square tests and logistic regression. Qualitative data was analysed using content analysis. of the participants, 59% of the African black students were successful compared to 90% of the white students.  A significant association was found between race and success with factors such as sharing a residence room, obtaining information about university support systems from classmates, feeling part of the group of classmates and choosing physiotherapy as the first choice of career being predictors of success. Students also highlighted determination to succeed and become a physiotherapist, financial and family support, and a favourable learning environment to contribute to success. HOD interviews associated adequate knowledge about the physiotherapy profession, proficiency in the language of instruction, academic discipline, relevant support and integration in the class with success. It is recommended that matriculation results should not be the only predictors of success but tertiary institutions should consider broader factors such as residential accommodation and a

  16. Neighborhood Safety and Major Depressive Disorder in a National Sample of Black Youth; Gender by Ethnic Differences

    Science.gov (United States)

    Assari, Shervin; Caldwell, Cleopatra Howard

    2017-01-01

    Adolescence is a developmental period marked by increased stress, especially among Black youth. In addition to stress related to their developmental transition, social factors such as a perceived unsafe neighborhood impose additional risks. We examined gender and ethnic differences in the association between perceived neighborhood safety and major depressive disorder (MDD) among a national sample of Black youth. We used data from the National Survey of American Life - Adolescents (NSAL-A), 2003–2004. In total, 1170 Black adolescents entered the study. This number was composed of 810 African American and 360 Caribbean Black youth (age 13 to 17). Demographic factors, perceived neighborhood safety, and MDD (Composite International Diagnostic Interview, CIDI) were measured. Logistic regressions were used to test the association between neighborhood safety and MDD in the pooled sample, as well as based on ethnicity by gender groups. In the pooled sample of Black youth, those who perceived their neighborhoods to be unsafe were at higher risk of MDD (Odds Ratio [OR] = 1.25; 95% Confidence Interval [CI] = 1.02-1.51). The perception that one’s neighborhood is unsafe was associated with a higher risk of MDD among African American males (OR=1.41; 95% CI = 1.03–1.93) but not African American females or Caribbean Black males and females. In conclusion, perceived neighborhood safety is not a universal psychological determinant of MDD across ethnic by gender groups of Black youth; however, policies and programs that enhance the sense of neighborhood safety may prevent MDD in male African American youth. PMID:28241490

  17. Black-Brown Relations: Are Alliances Possible?

    Science.gov (United States)

    Klor de Alva, J. Jorge; West, Cornel

    1997-01-01

    Dialogue between Cornel West and Jorge Klor de Alva explores the question of black-brown alliances, those between African Americans and Hispanic Americans. If minority groups can put aside the difference of skin color and join to combat economic and social racism, they can have far-reaching and meaningful impacts on society. (SLD)

  18. Understanding and Developing Black Popular Music Collections.

    Science.gov (United States)

    Murray, James Briggs

    1983-01-01

    Enumerates types of black popular music (work songs, spirituals, gospel music, blues, race records, rock and roll, soul, funk, disco, Caribbean, and African) and discusses collection development (current, retrospective, monographs, periodicals, sheet music, motion picture film, photographs, oral history), cataloging, and preservation. A 229-item…

  19. Spirituality, Religiousness, and Alcoholism Treatment Outcomes: A Comparison between Black and White Participants

    Science.gov (United States)

    Krentzman, Amy R.; Farkas, Kathleen J.; Townsend, Aloen L.

    2012-01-01

    This study addresses an unexplained finding in the alcoholism treatment field: despite the health and socioeconomic disparities that exist between blacks and whites at intake, blacks and whites achieve equivalent treatment outcomes. Using Project MATCH data, this study explores religiousness and spirituality as strengths in the African American community that may account in part for equivalent outcomes. Using binary logistic regression, this study found that as purpose in life increased, blacks were more likely to achieve sobriety than whites. This study provides evidence that purpose in life is a cultural strength and an advantage among blacks in achieving sobriety. PMID:22707846

  20. The Black Lives Matter Movement and Historically Black Colleges and Universities

    Science.gov (United States)

    Gasman, Marybeth

    2017-01-01

    This article looks at the Black Lives Matter Movement and Historically Black Colleges and Universities. Historically Black Colleges and Universities (HBCUs) continue to play an important role in society. However, what the Black Lives Matter movement shows consistently is that predominantly White institutions need to change, to step up and embrace…

  1. National Black HIV/AIDS Awareness Day

    Centers for Disease Control (CDC) Podcasts

    In observance of National Black HIV/AIDS Awareness Day, Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, talks about the HIV/AIDS among African Americans and what steps can be taken on the national, state, local, and individual levels to address this epidemic.

  2. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.'s multicenter supersymmetric black hole solutions provides a supergravity description of such backgrounds within which a black hole can be trapped within a confined volume. This construction is realized by solving for a levitating black hole over a magnetic dipole base. We comment on how such a construction is akin to a mechanical levitron.

  3. Black Holes

    OpenAIRE

    Horowitz, Gary T.; Teukolsky, Saul A.

    1998-01-01

    Black holes are among the most intriguing objects in modern physics. Their influence ranges from powering quasars and other active galactic nuclei, to providing key insights into quantum gravity. We review the observational evidence for black holes, and briefly discuss some of their properties. We also describe some recent developments involving cosmic censorship and the statistical origin of black hole entropy.

  4. "I, Black woman, resist]" Katrina Payne talks to Alzira Rufino. Interview.

    Science.gov (United States)

    Payne, K

    1995-02-01

    In this interview, Alzira Rufino describes her involvement in the feminist movement and what caused her to found the Black Women's House of Culture in Brazil in 1990. Rufino located the center in Santos because it is a port city which sees a great deal of violence and is very sexist and racist. The center, which exists to assist all women, grew out of a Rufino's realization that Black women needed a group to support their rights. The name for the center came from the fact that women have been the keepers of African culture in Brazil. In Brazil, White men dominate the culture, even the cultural expressions produced by Black people such as the Carnival. The center has had to overcome the criticism directed at it because it was created for women and for Black women in particular, and Black feminists are beginning to understand that Black women make up 25% of the population of Brazil and must celebrate their heritage. Increasing the self-esteem of Black women can be instrumental in helping women undergo training for better jobs and to take the initiative to become entrepreneurs. Black women in Brazil are beginning to occupy positions formerly denied them and to denounce the racism and sexism directed toward them.

  5. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M

    2003-01-01

    Methods and results of searching for stellar mass black holes in binary systems and for supermassive black holes in galactic nuclei of different types are described. As of now (June 2002), a total of 100 black hole candidates are known. All the necessary conditions Einstein's General Relativity imposes on the observational properties of black holes are satisfied for candidate objects available, thus further assuring the existence of black holes in the Universe. Prospects for obtaining sufficient criteria for reliably distinguishing candidate black holes from real black holes are discussed. (reviews of topical problems)

  6. Black versus Black: The Relationship among African, African American, and African Caribbean Persons.

    Science.gov (United States)

    Jackson, Jennifer V.; Cothran, Mary E.

    2003-01-01

    Surveyed people of African descent regarding relationships among African, African-American, and African-Caribbean persons, focusing on contact and friendship, travel to countries of the diaspora, cross-cultural communication, thoughts and stereotypes, and education. Most respondents had contacts with the other groups, but groups had preconceived…

  7. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  8. Beyoncé’s Slay Trick: The Performance of Black Camp and its Intersectional Politics

    Directory of Open Access Journals (Sweden)

    Chatzipapatheodoridis Constantine

    2017-12-01

    Full Text Available This article pays attention to African-American artist Beyonce Knowles and her performance of black camp. Beyonce’s stage persona and performances invite multiple ideological readings as to what pertains to her interpretation of gender, sexuality, and race. While cultural theory around the icon of Beyonce has focused on her feminist and racial politics as well as her politicization of the black female body, a queer reading applied from the perspective of camp performance will concentrate on the artist’s queer appeal and, most importantly, on her exposition of black camp, an intersection of feminist, racial and queer poetics. By examining video and live performances, the scope of this article is to underline those queer nuances inherent in Beyonce’s dramatisation of black femininity and the cultural pool she draws from for its effective staging. More specifically, since Beyonce plays with tropes and themes that are common in camp culture, her performance relies on a meta-camping effect that interacts with African-American queer culture. This article, thus, traces black queer traditions and discourses in the artist’s praxis of black camp.

  9. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    large values of Ф, black holes do form and for small values the scalar field ... on the near side of the ridge ultimately evolve to form black holes while those configu- ... The inset shows a bird's eye view looking down on the saddle point.

  10. Black widow spider

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002858.htm Black widow spider To use the sharing features on this page, please enable JavaScript. The black widow spider (Latrodectus) has a shiny black body with a ...

  11. Developing Critical Hip Hop Feminist Literacies: Centrality and Subversion of Sexuality in the Lives of Black Girls

    Science.gov (United States)

    Richardson, Elaine

    2013-01-01

    The present article explores discourses surrounding the bodies of Black women and girls as they engage the meanings of Black womanhood in (American) society in an afterschool setting. Drawing on Black and hip hop feminisms, African American literacies, and critical discourse perspectives, the author analyzes two young girls' narratives, which…

  12. A Dancing Black Hole

    Science.gov (United States)

    Shoemaker, Deirdre; Smith, Kenneth; Schnetter, Erik; Fiske, David; Laguna, Pablo; Pullin, Jorge

    2002-04-01

    Recently, stationary black holes have been successfully simulated for up to times of approximately 600-1000M, where M is the mass of the black hole. Considering that the expected burst of gravitational radiation from a binary black hole merger would last approximately 200-500M, black hole codes are approaching the point where simulations of mergers may be feasible. We will present two types of simulations of single black holes obtained with a code based on the Baumgarte-Shapiro-Shibata-Nakamura formulation of the Einstein evolution equations. One type of simulations addresses the stability properties of stationary black hole evolutions. The second type of simulations demonstrates the ability of our code to move a black hole through the computational domain. This is accomplished by shifting the stationary black hole solution to a coordinate system in which the location of the black hole is time dependent.

  13. Black generation Y students' perceptions of national sport celebrity ...

    African Journals Online (AJOL)

    African Journal for Physical Activity and Health Sciences ... Black generation Y students' perceptions of national sport celebrity endorsers as role models ... at tertiary institutions constitute a particularly attractive target market to marketers given ...

  14. An Analysis of Stereotype Threat in African American Engineering Students at Predominantly White, Ethnically Diverse, and Historically Black Colleges and Universities

    Science.gov (United States)

    Sparks, David M.

    2013-01-01

    The purpose of this research was to distinguish the similarities and differences in coping strategies of African American engineering students by analyzing their perceptions of stereotype threat at three academic institution types, Predominantly White Institutions (PWI), ethnically diverse, and Historically Black Colleges and Universities (HBCUs).…

  15. Exploratory factor structure of the neurological evaluation scale in black africans with first episode schizophrenia

    Directory of Open Access Journals (Sweden)

    Akin Ojagbemi

    2016-03-01

    Full Text Available While the organization of neurological soft signs (NSS in schizophrenia into Sensory integration, Motor coordination, and Motor sequencing, is functionally ‘meaningful’, it has not been confirmed by empirical methods such as factor analysis. Data on the exploratory factor analysis of the Neurological Evaluation scale in Black Africans with first episode schizophrenia are presented in this report. Data on the confirmatory factor structure of NSS in this population as well as their interpretation can be found in the work by Ojagbemi et al. (2015 [7].

  16. Education in the Black Diaspora: Perspectives, Challenges, and Prospects. Routledge Research in Education

    Science.gov (United States)

    Freeman, Kassie, Ed.; Johnson, Ethan, Ed.

    2011-01-01

    This volume gathers scholars from around the world in a comparative approach to the various educational struggles of people of African descent, advancing the search for solutions and bringing to light new facets of the experiences of black people in the era of globalization. This book begins with "Black Populations in the Diaspora:…

  17. A Structural Equation Model of HIV-Related Stigma, Racial Discrimination, Housing Insecurity and Wellbeing among African and Caribbean Black Women Living with HIV in Ontario, Canada.

    Directory of Open Access Journals (Sweden)

    Carmen H Logie

    Full Text Available African and Caribbean Black women in Canada have new HIV infection rates 7 times higher than their white counterparts. This overrepresentation is situated in structural contexts of inequities that result in social, economic and health disparities among African and Caribbean Black populations. Economic insecurity is a distal driver of HIV vulnerability, reducing access to HIV testing, prevention and care. Less is known about how economic insecurity indicators, such as housing security, continue to influence the lives of women living with HIV following HIV-positive diagnoses. The aim of this study was to test a conceptual model of the pathways linking HIV-related stigma, racial discrimination, housing insecurity, and wellbeing (depression, social support, self-rated health. We implemented a cross-sectional survey with African and Caribbean Black women living with HIV in 5 Ontario cities, and included 157 participants with complete data in the analyses. We conducted structural equation modeling using maximum likelihood estimation to evaluate the hypothesized conceptual model. One-fifth (22.5%; n = 39 of participants reported housing insecurity. As hypothesized, racial discrimination had significant direct effects on: HIV-related stigma, depression and social support, and an indirect effect on self-rated health via HIV-related stigma. HIV-related stigma and housing insecurity had direct effects on depression and social support, and HIV-related stigma had a direct effect on self-rated health. The model fit the data well: χ2 (45, n = 154 = 54.28, p = 0.387; CFI = 0.997; TLI = 0.996; RMSEA = 0.016. Findings highlight the need to address housing insecurity and intersecting forms of stigma and discrimination among African and Caribbean Black women living with HIV. Understanding the complex relationships between housing insecurity, HIV-related stigma, racial discrimination, and wellbeing can inform multi-level interventions to reduce stigma and enhance

  18. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  19. Perceived Neighborhood Quality and HIV-related Stigma among African Diasporic Youth; Results from the African, Caribbean, and Black Youth (ACBY) Study.

    Science.gov (United States)

    Kerr, Jelani; Northington, Toya; Sockdjou, Tamara; Maticka-Tyndale, Eleanor

    2018-01-01

    Socio-environmental factors such as neighborhood quality are increasingly recognized drivers of HIV disparities. Additionally, HIV- related stigma heightens HIV vulnerability among youth in the African Diaspora. However, little research examines the intersection of neighborhood quality and HIV- related stigma. This study uses survey data (N=495) from African, Caribbean, and Black youth in a midsized city in Ontario, Canada to address this research deficit. Analysis of variance and multivariate ordinary least squares regressions were conducted to determine differences in HIV- related stigma by neighborhood quality, experiences of discrimination, HIV- knowledge, and demographic factors. Residents in more socially disordered neighborhoods (p<.05), males (p<.0001), African- Muslim youth (p<.01), and individuals with lower HIV- knowledge (p<.0001) endorsed stigmatizing beliefs more often. Addressing neighborhood disadvantage may have implications for HIV- related stigma. More research should be conducted to understand the impact of socio- environmental disadvantage and HIV- related stigma.

  20. Segregation or "Thinking Black"?: Community Activism and the Development Of Black-Focused Schools in Toronto and London, 1968-2008

    Science.gov (United States)

    Johnson, Lauri

    2013-01-01

    Background/Context: On January 29, 2008 the Toronto District School Board (TDSB) approved a city-wide Africentric elementary school under their Alternative School policy, sparking a contentious debate. Calls for Black-focused schools also arose in 2008 in London in response to the disengagement of African Caribbean youth. The historical record…

  1. Lumpy AdS5× S5 black holes and black belts

    International Nuclear Information System (INIS)

    Dias, Óscar J.C.; Santos, Jorge E.; Way, Benson

    2015-01-01

    Sufficiently small Schwarzschild black holes in global AdS 5 ×S 5 are Gregory-Laflamme unstable. We construct new families of black hole solutions that bifurcate from the onset of this instability and break the full SO(6) symmetry group of the S 5 down to SO(5). These new “lumpy" solutions are labelled by the harmonics ℓ. We find evidence that the ℓ=1 branch never dominates the microcanonical/canonical ensembles and connects through a topology-changing merger to a localised black hole solution with S 8 topology. We argue that these S 8 black holes should become the dominant phase in the microcanonical ensemble for small enough energies, and that the transition to Schwarzschild black holes is first order. Furthermore, we find two branches of solutions with ℓ=2. We expect one of these branches to connect to a solution containing two localised black holes, while the other branch connects to a black hole solution with horizon topology S 4 ×S 4 which we call a “black belt”.

  2. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.

    1996-01-01

    Introduction Distinguishing neutron stars and black holes Optical companions and dynamical masses X-ray signatures of the nature of a compact object Structure and evolution of black-hole binaries High-mass black-hole binaries Low-mass black-hole binaries Low-mass black holes Formation of black holes

  3. Black Interpretation, Black American Literature, and Grey Audiences.

    Science.gov (United States)

    Washington, Earl M.

    1981-01-01

    Defines and illustrates language techniques used by Black authors writing to and for Blacks in the 1960s and 1970s. Suggests how language and theme barriers of such literature might be overcome in a contemporary integrated oral interpretation classroom. (PD)

  4. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.

    1980-01-01

    Conditions for the formation of a black hole are considered, and the properties of black holes. The possibility of Cygnus X-1 as a black hole is discussed. Einstein's theory of general relativity in relation to the formation of black holes is discussed. (U.K.)

  5. Gender nonconformity, discrimination, and mental health among Black South African men who have sex with men: A further exploration of unexpected findings

    NARCIS (Netherlands)

    Sandfort, T.; Bos, H.; Knox, J.; Reddy, V.

    2016-01-01

    Using data from a study about HIV risk among Black South African MSM, we aimed to ascertain whether unexpected findings about the relationship between gender nonconformity, discrimination, and mental health in this population, as reported by Cook, Sandfort, Nel, and Rich (2013), could be replicated,

  6. Black ringoids: spinning balanced black objects in d≥5 dimensions — the codimension-two case

    International Nuclear Information System (INIS)

    Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen

    2015-01-01

    We propose a general framework for the study of asymptotically flat black objects with k+1 equal magnitude angular momenta in d≥5 spacetime dimensions (with 0≤k≤[((d−5)/2)]). In this approach, the dependence on all angular coordinates but one is factorized, which leads to a codimension-two problem. This framework can describe black holes with spherical horizon topology, the simplest solutions corresponding to a class of Myers-Perry black holes. A different set of solutions describes balanced black objects with S"n"+"1×S"2"k"+"1 horizon topology. The simplest members of this family are the black rings (k=0). The solutions with k>0 are dubbed black ringoids. Based on the nonperturbative numerical results found for several values of (n,k), we propose a general picture for the properties and the phase diagram of these solutions and the associated black holes with spherical horizon topology: n=1 black ringoids repeat the k=0 pattern of black rings and Myers-Perry black holes in 5 dimensions, whereas n>1 black ringoids follow the pattern of higher dimensional black rings associated with ‘pinched’ black holes and Myers-Perry black holes.

  7. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-01-01

    Macroscopic entropy of an extremal black hole is expected to be determined completely by its near horizon geometry. Thus two black holes with identical near horizon geometries should have identical macroscopic entropy, and the expected equality between macroscopic and microscopic entropies will then imply that they have identical degeneracies of microstates. An apparent counterexample is provided by the 4D-5D lift relating BMPV black hole to a four dimensional black hole. The two black holes have identical near horizon geometries but different microscopic spectrum. We suggest that this discrepancy can be accounted for by black hole hair - degrees of freedom living outside the horizon and contributing to the degeneracies. We identify these degrees of freedom for both the four and the five dimensional black holes and show that after their contributions are removed from the microscopic degeneracies of the respective systems, the result for the four and five dimensional black holes match exactly.

  8. Teacher Education and Black Male Students in the United States

    Directory of Open Access Journals (Sweden)

    H. Richard Milner

    2013-10-01

    Full Text Available Teacher education programs in the United States (U.S. struggle to prepare teachers to meet the complex needs of elementary and secondary students in public schools - especially those of color, those living in poverty, and those whose first language is not English. In this article, we argue for focused attention on preparing educators to teach African American male students as these students face particular institutional challenges in successfully navigating the U.S. public school system. Drawing from the significant body of research on teacher education and teacher learning for equity and social justice, four Black teacher educators discuss challenges they have faced in classes designed to prepare teachers to teach Black male students. Through an analysis of commonalities in their experiences, they propose means for teacher educators to foster greater understandings of the heterogeneity found among Black male students so that teachers can craft more responsive and responsible educational experiences for Black males.

  9. African American Students in a California Community College: Perceptions of Cultural Congruity and Academic Self-Concept within a Black Culture Center

    Science.gov (United States)

    James, Tenisha Celita

    2017-01-01

    This study focused on the cultural congruity and academic self-concept of African American students in a community college setting who participated in a Black Culture Center. The purpose of this quantitative correlational study was to examine the relationship between cultural congruity and academic self-concept through the following two research…

  10. (Re)visualizing Black lesbian lives, (trans)masculinity, and township space in the documentary work of Zanele Muholi.

    Science.gov (United States)

    Imma, Z'étoile

    2017-04-03

    This article explores the politics of representing Black queer and trans subjectivities in the recent documentary film and photography of South African lesbian visual activist Zanele Muholi. While Muholi's work has been most often been positioned as an artistic response to the hate-crimes and violence perpetuated against Black lesbians in South African townships, most notably acts of sexual violence known increasingly as corrective rape, I argue that Muholi's documentary texts trouble the spatial, gendered, and highly racialized articulations that make up an increasingly global corrective rape discourse. The article considers how her visual texts foreground and (re)visualize Black queer and trans gender experiences that relocate, challenge, collaborate with, and at times, perform, masculinity as means to subvert heterosexist and racist constructions of township space and the Black gendered body.

  11. UH-60M Black Hawk Helicopter (UH-60M Black Hawk)

    Science.gov (United States)

    2016-12-01

    Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-341 UH-60M Black Hawk Helicopter (UH-60M Black Hawk ) As of FY 2017 President’s Budget Defense...Acquisition Management Information Retrieval (DAMIR) March 21, 2016 18:25:45 UNCLASSIFIED UH-60M Black Hawk December 2015 SAR March 21, 2016 18...Operational Requirements Document OSD - Office of the Secretary of Defense O&S - Operating and Support PAUC - Program Acquisition Unit Cost UH-60M Black Hawk

  12. Black Tea

    Science.gov (United States)

    ... mental alertness as well as learning, memory, and information processing skills. It is also used for treating headache; ... of carbamazepine. Since black tea contains caffeine, in theory taking black tea with carbamazepine might decrease the ...

  13. Black holes are warm

    International Nuclear Information System (INIS)

    Ravndal, F.

    1978-01-01

    Applying Einstein's theory of gravitation to black holes and their interactions with their surroundings leads to the conclusion that the sum of the surface areas of several black holes can never become less. This is shown to be analogous to entropy in thermodynamics, and the term entropy is also thus applied to black holes. Continuing, expressions are found for the temperature of a black hole and its luminosity. Thermal radiation is shown to lead to explosion of the black hole. Numerical examples are discussed involving the temperature, the mass, the luminosity and the lifetime of black mini-holes. It is pointed out that no explosions corresponding to the prediction have been observed. It is also shown that the principle of conservation of leptons and baryons is broken by hot black holes, but that this need not be a problem. The related concept of instantons is cited. It is thought that understanding of thermal radiation from black holes may be important for the development of a quantified gravitation theory. (JIW)

  14. Nutritional Genetics: The Case of Alcohol and the MTHFR C677T Polymorphism in relation to homocysteine in a Black South African Population

    NARCIS (Netherlands)

    Nienaber-Rousseau, C.; Pisa, P.T.; Venster, C.S.; Ellis, S.M.; Kruger, A.; Moss, S.; Boonstra, A.; Towers, G.W.

    2013-01-01

    Background/Aims: It is unknown whether the effect of alcohol consumption on homocysteine (Hcy) is modulated by the methylenetetrahydrofolate reductase (MTHFR) C677T. We explored this hypothesized effect by analyzing cross-sectional data of 1,827 black South Africans. Methods: Total Hcy

  15. Is It because I'm Black? A Black Female Research Experience

    Science.gov (United States)

    Maylor, Uvanney

    2009-01-01

    This article examines what it means to be a Black female researcher in contemporary Britain. Drawing on Black feminist theory and critical race theory (CRT), this article seeks to highlight some of the experiences and challenges that Black female researchers face when undertaking research, particularly research that has diversity, equality or…

  16. The stable problem of the black-hole connected region in the Schwarzschild black hole

    OpenAIRE

    Tian, Guihua

    2005-01-01

    The stability of the Schwarzschild black hole is studied. Using the Painlev\\'{e} coordinate, our region can be defined as the black-hole-connected region(r>2m, see text) of the Schwarzschild black hole or the white-hole-connected region(r>2m, see text) of the Schwarzschild black hole. We study the stable problems of the black-hole-connected region. The conclusions are: (1) in the black-hole-connected region, the initially regular perturbation fields must have real frequency or complex frequen...

  17. Low Family Support and Risk of Obesity among Black Youth: Role of Gender and Ethnicity.

    Science.gov (United States)

    Assari, Shervin; Caldwell, Cleopatra Howard

    2017-05-12

    Most studies on the role of family environment in developing risk of obesity among youth have focused on parenting behaviors that are directly involved in energy balance in regional, non-representative White samples. Using a national sample of ethnically diverse Black youth, the current study tested the association between low family support and risk of obesity. We also tested the heterogeneity of this association based on gender, ethnicity, and their intersection. We used data from the National Survey of American Life-Adolescent Supplement (NSAL-A), a national survey of Black adolescents in the United States. The study enrolled 1170 African American and Caribbean Black 13-17 year old youth. Obesity was defined based on the cutoff points of body mass index (BMI) appropriate for age and gender of youth. Family support was measured using a five-item measure that captured emotional and tangible social support. Age, gender, and ethnicity were also measured. Logistic regressions were utilized in the pooled sample, and also based on gender, ethnicity, and their intersection, to test the link between low family support and risk for obesity. In the pooled sample, low family support was not associated with an increased risk of obesity (OR = 1.35, 95% Confidence Interval (CI) = 0.96-1.89). The association between low family support and risk of obesity was, however, significant among African American females (OR = 1.60, 95% CI = 1.01-2.55). There was no association for African American males (OR = 1.26, 95% CI = 0.82-1.92), Caribbean Black males (OR = 0.68, 95% CI = 0.01-54.85), and Caribbean Black females (OR = 0.78, 95% CI = 0.42-1.44). In conclusion, policies and programs that enable African American families to provide additional family support may prevent obesity among African American female youth. Future research should test the efficacy of promoting family support as a tool for preventing obesity among African American female youth.

  18. Clinical, immunologic and insulin secretory characteristics of young black South African patients with diabetes: Hospital based single centre study.

    Science.gov (United States)

    Ekpebegh, C O; Longo-Mbenza, B

    2013-03-01

    To classify and characterize the clinical features of various diabetes classes among young black South Africans. Cross sectional study of 60 black patients with diabetes, all less than 30 years of age and attending Nelson Mandela Academic Hospital, Mthatha, South Africa. Diabetes was classified as Types 1A, 1B and 2 based on the anti-glutamic acid decarboxylase status and serum C-peptide response to intravenous injection of glucagon. Mean age was 19.6±4.8 years (n=60) with similar gender distribution. The mean duration of diabetes was 24.2±45.1 months. Type 1A was the class of diabetes in 55% (n=33/60) of patients. Type 1B and 2 accounted for 30% (n=18/60) and 15% (n=9/60) of patients respectively. Patients classified as Type 2 had higher waist circumference and higher prevalence of acanthosis nigricans than Types 1A and 1B groups. History of diabetes in a first degree relative and hypertension were found in similar proportions of patients with Types 1A, 1B and 2 diabetes. Five Type 1A diabetes patients had body mass index of 26.2-41kg/m(2) and this included two newly diagnosed patients with body mass index of 26.7kg/m(2) and 33.2kg/m(2). The majority of our young black South Africans with diabetes are of the Type 1A class. Acanthosis nigricans was not found in any patient with Type 1 A diabetes. A minority of Type 1 A diabetes patients were obese at initial diagnosis. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. [Selective laser trabeculoplasty (SLT): our experience in African blacks].

    Science.gov (United States)

    Seck, S M; Agboton, G; Dieng, M; Ndiaye Sow, M N; Diakhate, M; Gueye, N N; Seck, C M; Lam, A

    2015-03-01

    The purpose of our study was to evaluate in the short and medium term, intraocular pressure results after selective laser trabeculoplasty in black patients with chronic open angle glaucoma or isolated ocular hypertension. We conducted a retrospective study with a mean 12.5-month follow-up in black patients who underwent SLT. Inclusion criteria were: an open iridocorneal angle greater than or equal to Schaeffer grade 3, data recorded and available on trabecular pigmentation, data on SLT parameters available, and intraocular pressure by Goldmann applanation tonometry recorded.A positive result was defined as a post-laser IntraOcular Pressure (IOP) less than 21 mmHg after 1-month follow-up. The main motivation was the reduction of number of eye drops used. Performed first was a treatment of the inferior 180° (3:00-9:00), possibly supplemented by a second session at 15 days or 1 month if a pressure decrease was noted after the first session. IOP results were evaluated prior to SLT, immediately following SLT and then depending on the drop in pressure. Statistical analysis was performed using the EPI.info 7 software. A total of 69 eyes of 40 patients treated with SLT were identified. The mean IOP prior to SLT was 18.3 mmHg ± 4. Our results showed 90% of patients who positively responded to the treatment (10% failure) with a mean IOP decrease of 2.3 ± 1 mmHg, that is 13%, by the second week. The mean pressure decrease continued to 4.78 ± 1 mmHg for patients (30%) in the group treated for 360°, that is 27% in the same period of time. SLT permitted discontinuation of a prostaglandin in 60% (42 cases). Eyes on triple-drug therapy went from 23 before SLT to 5 following SLT (a 26% decline), eyes on two medications went from 32 to 16 (24% decline). In result association tests, only pigmentation of the angle and visual field stage had a statistically significant probability. In our experience, SLT is indicated in black patients to potentiate less effective treatments, to

  20. Quantum aspects of black holes

    CERN Document Server

    2015-01-01

    Beginning with an overview of the theory of black holes by the editor, this book presents a collection of ten chapters by leading physicists dealing with the variety of quantum mechanical and quantum gravitational effects pertinent to black holes. The contributions address topics such as Hawking radiation, the thermodynamics of black holes, the information paradox and firewalls, Monsters, primordial black holes, self-gravitating Bose-Einstein condensates, the formation of small black holes in high energetic collisions of particles, minimal length effects in black holes and small black holes at the Large Hadron Collider. Viewed as a whole the collection provides stimulating reading for researchers and graduate students seeking a summary of the quantum features of black holes.

  1. The role of emerging black business: An interview with Kgalema ...

    African Journals Online (AJOL)

    The role of emerging black business: An interview with Kgalema Motlanthe. ... New Agenda: South African Journal of Social and Economic Policy. Journal Home · ABOUT THIS ... Open Access DOWNLOAD FULL TEXT Subscription or Fee ...

  2. The Frequency of Cytochrome P450 2E1 Polymorphisms in Black South Africans

    Directory of Open Access Journals (Sweden)

    Paul K. Chelule

    2006-01-01

    Full Text Available Polymorphisms in the promoter region of the Cytochrome P4502E1 (CYP2E1 gene reportedly modify the metabolic activity of CYP2E1 enzyme, and have been associated with increased susceptibility to squamous cell carcinoma (SCC of the oesophagus in high prevalence areas such as China. To assess the frequency of these polymorphisms in Black South Africans, a population with a high incidence of oesophageal SCC, this study examined genomic DNA from 331 subjects for restriction fragment length polymorphisms in the CYP2E1 (RsaI and PstI digestion. The frequency of the CYP2E1 c1/c1 and c1/c3 genotypes was 95% and 5% respectively. The frequency of the CYP2E1 allele distribution was found to be markedly different between Chinese and South African populations; hence it is important to place racial differences into consideration when proposing allelic variants as genetic markers for cancer.

  3. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  4. Complicated Contradictions Amid Black Feminism and Millennial Black Women Teachers Creating Curriculum for Black Girls

    Science.gov (United States)

    Nyachae, Tiffany M.

    2016-01-01

    Millennial Black women teachers wrestle with two simultaneous burdens: disrupting the racist and sexist status quo of schooling through curriculum, and employing tactics to survive school politics among their majority White women colleagues. This article describes how the "Sisters of Promise" (SOP) curriculum aligned with Black feminism…

  5. Snake velvet black: Hierarchical micro- and nanostructure enhances dark colouration in Bitis rhinoceros

    Science.gov (United States)

    Spinner, Marlene; Kovalev, Alexander; Gorb, Stanislav N.; Westhoff, Guido

    2013-05-01

    The West African Gaboon viper (Bitis rhinoceros) is a master of camouflage due to its colouration pattern. Its skin is geometrically patterned and features black spots that purport an exceptional spatial depth due to their velvety surface texture. Our study shades light on micromorphology, optical characteristics and principles behind such a velvet black appearance. We revealed a unique hierarchical pattern of leaf-like microstructures striated with nanoridges on the snake scales that coincides with the distribution of black colouration. Velvet black sites demonstrate four times lower reflectance and higher absorbance than other scales in the UV - near IR spectral range. The combination of surface structures impeding reflectance and absorbing dark pigments, deposited in the skin material, provides reflecting less than 11% of the light reflected by a polytetrafluoroethylene diffuse reflectance standard in any direction. A view-angle independent black structural colour in snakes is reported here for the first time.

  6. Black deaf individuals' reading skills: influence of ASL, culture, family characteristics, reading experience, and education.

    Science.gov (United States)

    Myers, Candace; Clark, M Diane; Musyoka, Millicent M; Anderson, Melissa L; Gilbert, Gizelle L; Agyen, Selina; Hauser, Peter C

    2010-01-01

    Previous research on the reading abilities of Deaf individuals from various cultural groups suggests that Black Deaf and Hispanic Deaf individuals lag behind their White Deaf peers. The present study compared the reading skills of Black Deaf and White Deaf individuals, investigating the influence of American Sign Language (ASL), culture, family characteristics, reading experience, and education. (The descriptor Black is used throughout the present article, as Black Deaf individuals prefer this term to African American. For purposes of parallel construction, the term White is used instead of European American.) It was found that Black Deaf study participants scored lower on measures of both reading and ASL. These findings provide implications for possible interventions at the primary, secondary, and college levels of education.

  7. Rotating black holes at future colliders. III. Determination of black hole evolution

    International Nuclear Information System (INIS)

    Ida, Daisuke; Oda, Kin-ya; Park, Seong Chan

    2006-01-01

    TeV scale gravity scenario predicts that the black hole production dominates over all other interactions above the scale and that the Large Hadron Collider will be a black hole factory. Such higher-dimensional black holes mainly decay into the standard model fields via the Hawking radiation whose spectrum can be computed from the greybody factor. Here we complete the series of our work by showing the greybody factors and the resultant spectra for the brane-localized spinor and vector field emissions for arbitrary frequencies. Combining these results with the previous works, we determine the complete radiation spectra and the subsequent time evolution of the black hole. We find that, for a typical event, well more than half a black hole mass is emitted when the hole is still highly rotating, confirming our previous claim that it is important to take into account the angular momentum of black holes

  8. The mental health of US Black women: the roles of social context and severe intimate partner violence.

    Science.gov (United States)

    Lacey, Krim K; Parnell, Regina; Mouzon, Dawne M; Matusko, Niki; Head, Doreen; Abelson, Jamie M; Jackson, James S

    2015-10-19

    Black women continue to have rates of mental health conditions that can be negative for their well-being. This study examined the contribution of social and contextual factors and severe physical intimate partner violence on the mental health of US Black women (African-American and Caribbean Black). Data were largely collected via in-person community interviews at participants' homes. We studied 3277 African-American and Black Caribbean women from the 2001-2003 National Survey of American Life (NSAL), the largest and most complete sample of Blacks residing in the USA. Key outcomes included an array of psychiatric disorders based on the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Bivariate results revealed noticeably high rates of any anxiety disorder, post-traumatic stress disorder, any substance disorder, alcohol abuse disorder, suicide ideation and attempts, and any overall mental disorder among African-American women relative to Caribbean Black women. Multiple social and contextual factors were associated with various mental disorders among both sets of Black women in multivariate models, with the most consistent associations found for severe physical intimate partner violence. Everyday discrimination was associated with anxiety disorders (95% AOR=2.08 CI 1.23 to 3.51), eating disorders (95% AOR=2.69 CI 1.38 to 5.22), and any disorder (95% AOR=2.18 CI 1.40 to 3.40), while neighbourhood drug problems contributed to mood (95% AOR=1.19 CI 1.04 to 1.36), substance disorders (95% AOR=1.37 CI 1.11 to 1.69) and any disorder (95% AOR=1.18 CI 1.03 to 1.34). Severe physical intimate partner violence, discrimination, and to a lesser extent, neighbourhood problems are important predictors of Black women's health, findings that inform intervention and clinical services tailored to meet the needs of Black women from diverse ethnic and cultural backgrounds. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under

  9. Difficulties encountered by black women entrepreneurs in accessing ...

    African Journals Online (AJOL)

    The long period of colonialism and apartheid, imposed oppression and exploitation on women especially black African women, meant that they could not own property in their own rights or enter into a contract. The dawn of democracy brought about changes in the role played by women. They have emerged significantly ...

  10. BlackBerry For Dummies

    CERN Document Server

    Kao, Robert

    2010-01-01

    Get the most juice out of your BlackBerry handheld!. Feature-rich and complex, the BlackBerry is the number one smartphone in the corporate world is among the most popular handhelds for business users. This new and updated edition includes all the latest and greatest information on new and current BlackBerry mobile devices. Covering a range of valuable how-to topics, this helpful guide explores the BlackBerry's most useful features, techniques for getting the most out of your BlackBerry, and practical information about power usage.: Covers all aspects of the number one smartphone in the corpor

  11. TYPES OF ALBINISM IN THE BLACK SOUTHERN AFRICA POPULATION.

    Science.gov (United States)

    Kromberg, J G R; Bothwell, J; Kidson, S H; Manga, P; Kerr, R; Jenkins, T

    2012-01-01

    Oculocutaneous albinism (OCA) is the most common inherited disorder in Southern African blacks and several types have been described. Molecular techniques, where available, can be used to confirm a clinical diagnosis and the type of OCA, if necessary, and for prenatal diagnosis. To investigate and classify the different types of albinism commonly found and to determine the clinical implications for each type. A descriptive survey. Gauteng province, South Africa, and Lesotho. Three groups of subjects with OCA (96 from a genetics clinic, 62 from a dermatology clinic, and 31 from community surveys) from the black African population participated. Subjects underwent clinical and/or dermatological examinations and were then classified according to type of OCA. Four forms of OCA were identified: most (82%) subjects had OCA2 (a tyrosinase- positive type) with three sub-types: those without large freckles (ephelides) on exposed areas (named OCA 2a in this study), those with such freckles (named OCA 2b), and those with brown albinism (BOCA); the remainder had red/rufous albinism, ROCA (OCA 3). The four forms could be distinguished from each other clinically without using molecular genetic testing. The most common types of albinism found in the black population of Southern Africa are OCA2 and OCA3. Given the high prevalence of the disorder, together with the high risk of skin cancer, and the recent persecution of affected individuals in certain East African countries, these findings and their clinical implications have significance in terms of both education and awareness for health professionals and lay people caring for those with albinism.

  12. Il sistema calpaina/calpastatina in 3 muscoli dell’arto pelvico di struzzo African Black. Studio istochimico, immunoistochimico e morfometrico

    OpenAIRE

    Gomez De Ayala, Diego

    2006-01-01

    In the present research a description of the pelvic limb musculature of ostrich (African Black) was given. Muscle tissues were obtained from three muscles namely: Gastrocnemius pars externa, Tibialis .cranialis caput tibiale, Tbialis cranialis caput femorale. Haematoxilin-eosin technique was used to verify the morphologic aspect of the tissues (fibers integrity). The histochemical results revealed the presence of three fibre types only in the gastrocnemus pars extena uscle : slow-twitch o...

  13. Black Hole Area Quantization rule from Black Hole Mass Fluctuations

    OpenAIRE

    Schiffer, Marcelo

    2016-01-01

    We calculate the black hole mass distribution function that follows from the random emission of quanta by Hawking radiation and with this function we calculate the black hole mass fluctuation. From a complete different perspective we regard the black hole as quantum mechanical system with a quantized event horizon area and transition probabilities among the various energy levels and then calculate the mass dispersion. It turns out that there is a perfect agreement between the statistical and ...

  14. Framing black boys: parent, teacher, and student narratives of the academic lives of black boys.

    Science.gov (United States)

    Rowley, Stephanie J; Ross, Latisha; Lozada, Fantasy T; Williams, Amber; Gale, Adrian; Kurtz-Costes, Beth

    2014-01-01

    The discourse on Black boys tends to suggest that Black boys are in complete peril. We begin with evidence that Black boys are excelling in certain contexts (i.e., in certain states, in certain schools, and in certain courses). We then discuss the ways in which the narratives used by parents, teachers, and Black boys themselves may serve to further reinforce views that Black boys are beyond hope. Research on Black parents suggests that they tend to view their sons as vulnerable and have lower expectations for sons than for daughters. Studies of teachers show that they tend to view Black boys as unteachable, as social problems, and as scary. Research on Black boys shows that they are sometimes complicit in supporting these narratives by engaging in negative or ste reotypical behavior. We also include recent research that includes counter-narratives of Black boys. We end with suggestions for future research.

  15. Black Undergraduate Students Attitude toward Counseling and Counselor Preference

    Science.gov (United States)

    Duncan, Lonnie E.; Johnson, Darrell

    2007-01-01

    A help seeking survey and measures of socioeconomic status, cultural mistrust, and African Self-consciousness were administered to 315 Black college students to study attitudes toward counseling and counselor preference. Multiple Regression analysis indicated that gender, cultural mistrust, and socioeconomic status were statistically significant…

  16. Blastic Plasmacytoid Dendritic Cell Leukemia in a Black Malian

    African Journals Online (AJOL)

    2017-06-28

    Jun 28, 2017 ... BPDCN in Mali. KEYWORDS: Acute Leukemia, black african, dendritic cell, Mali ... myeloid neoplasm by the 2008 world health organization classification of .... There are many standardized treatment regimens, and many protocols with ... leukemia chemotherapy regimen[7,11] or chronic leukemia treatment ...

  17. Monopole Black Hole Skyrmions

    OpenAIRE

    Moss, Ian G; Shiiki, N; Winstanley, E

    2000-01-01

    Charged black hole solutions with pion hair are discussed. These can be\\ud used to study monopole black hole catalysis of proton decay.\\ud There also exist\\ud multi-black hole skyrmion solutions with BPS monopole behaviour.

  18. The Brain of the Black (Diceros bicornis and White (Ceratotherium simum African Rhinoceroses: Morphology and Volumetrics from Magnetic Resonance Imaging

    Directory of Open Access Journals (Sweden)

    Adhil Bhagwandin

    2017-08-01

    Full Text Available The morphology and volumetrics of the understudied brains of two iconic large terrestrial African mammals: the black (Diceros bicornis and white (Ceratotherium simum rhinoceroses are described. The black rhinoceros is typically solitary whereas the white rhinoceros is social, and both are members of the Perissodactyl order. Here, we provide descriptions of the surface of the brain of each rhinoceros. For both species, we use magnetic resonance images (MRI to develop a description of the internal anatomy of the rhinoceros brain and to calculate the volume of the amygdala, cerebellum, corpus callosum, hippocampus, and ventricular system as well as to determine the gyrencephalic index. The morphology of both black and white rhinoceros brains is very similar to each other, although certain minor differences, seemingly related to diet, were noted, and both brains evince the general anatomy of the mammalian brain. The rhinoceros brains display no obvious neuroanatomical specializations in comparison to other mammals previously studied. In addition, the volumetric analyses indicate that the size of the various regions of the rhinoceros brain measured, as well as the extent of gyrification, are what would be predicted for a mammal with their brain mass when compared allometrically to previously published data. We conclude that the brains of the black and white rhinoceros exhibit a typically mammalian organization at a superficial level, but histological studies may reveal specializations of interest in relation to rhinoceros behavior.

  19. Skyrmion black hole hair: Conservation of baryon number by black holes and observable manifestations

    Energy Technology Data Exchange (ETDEWEB)

    Dvali, Gia [Arnold Sommerfeld Center, Ludwig-Maximilians-Universität, 80333 München (Germany); Max-Planck-Institut für Physik, Werner-Heisenberg-Institut, 80805 München (Germany); Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place, New York, NY 10003 (United States); Gußmann, Alexander, E-mail: alexander.gussmann@physik.uni-muenchen.de [Arnold Sommerfeld Center, Ludwig-Maximilians-Universität, 80333 München (Germany)

    2016-12-15

    We show that the existence of black holes with classical skyrmion hair invalidates standard proofs that global charges, such as the baryon number, cannot be conserved by a black hole. By carefully analyzing the standard arguments based on a Gedankenexperiment in which a black hole is seemingly-unable to return the baryon number that it swallowed, we identify inconsistencies in this reasoning, which does not take into the account neither the existence of skyrmion black holes nor the baryon/skyrmion correspondence. We then perform a refined Gedankenexperiment by incorporating the new knowledge and show that no contradiction with conservation of baryon number takes place at any stage of black hole evolution. Our analysis also indicates no conflict between semi-classical black holes and the existence of baryonic gauge interaction arbitrarily-weaker than gravity. Next, we study classical cross sections of a minimally-coupled massless probe scalar field scattered by a skyrmion black hole. We investigate how the skyrmion hair manifests itself by comparing this cross section with the analogous cross section caused by a Schwarzschild black hole which has the same ADM mass as the skyrmion black hole. Here we find an order-one difference in the positions of the characteristic peaks in the cross sections. The peaks are shifted to smaller scattering angles when the skyrmion hair is present. This comes from the fact that the skyrmion hair changes the near horizon geometry of the black hole when compared to a Schwarzschild black hole with same ADM mass. We keep the study of this second aspect general so that the qualitative results which we obtain can also be applied to black holes with classical hair of different kind.

  20. Statistical black-hole thermodynamics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1975-01-01

    Traditional methods from statistical thermodynamics, with appropriate modifications, are used to study several problems in black-hole thermodynamics. Jaynes's maximum-uncertainty method for computing probabilities is used to show that the earlier-formulated generalized second law is respected in statistically averaged form in the process of spontaneous radiation by a Kerr black hole discovered by Hawking, and also in the case of a Schwarzschild hole immersed in a bath of black-body radiation, however cold. The generalized second law is used to motivate a maximum-entropy principle for determining the equilibrium probability distribution for a system containing a black hole. As an application we derive the distribution for the radiation in equilibrium with a Kerr hole (it is found to agree with what would be expected from Hawking's results) and the form of the associated distribution among Kerr black-hole solution states of definite mass. The same results are shown to follow from a statistical interpretation of the concept of black-hole entropy as the natural logarithm of the number of possible interior configurations that are compatible with the given exterior black-hole state. We also formulate a Jaynes-type maximum-uncertainty principle for black holes, and apply it to obtain the probability distribution among Kerr solution states for an isolated radiating Kerr hole

  1. Black holes without firewalls

    Science.gov (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

    2013-05-01

    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  2. The impact of local black residents' socioeconomic status on white residents' racial views.

    Science.gov (United States)

    Taylor, Marylee C; Reyes, Adriana M

    2014-01-01

    This paper extends the study of contextual influences on racial attitudes by asking how the SES of the local black community shapes the racial attitudes of local whites. Using responses to the 1998-2002 General Social Surveys merged with year 2000 census data, we compare the influences of black educational and economic composition on white residents' attitudes. Finally, the independence of these effects from the impact of white contextual SES is assessed. Across three dimensions of racial attitudes, white residents' views are more positive in localities where the black population contains more college graduates. However, such localities tend also to have highly educated white populations, as well as higher incomes among blacks and whites, and the multiple influences are inseparable. In contrast, many racial attitude measures show an independent effect of black economic composition, white residents reporting more negative views where the local African American community is poorer. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Fear of a Black femme: The existential conundrum of embodying a Black femme identity while being a professor of Black, queer, and feminist studies.

    Science.gov (United States)

    Story, Kaila Adia

    2017-10-02

    Although a Black femme identity has been defined and embodied by many as an identity with Black feminist roots and revolutionary potentials, Black femmes are still rendered hypervisible and invisible through racist and heteronormative politics. Similarly, embodying a Black femme identity as a professor in academia often engenders these same pretenses of hypervisibility and invisibility. This essay explores what this existential conundrum has been for me as both a Black femme and professor of Black queer and feminist studies, while illuminating the mix of forces within academia that have attempted to stifle my chosen sexual identity and gendered performance.

  4. Black Lives Matter of Black Identity Extremist? : The FBI, Black Activists and the Struggle for Victimhood

    NARCIS (Netherlands)

    Mutsaers, Paul

    2017-01-01

    The question 'who is the victim?' is an important social directive that shapes the struggles for victimhood in which Black Lives Matters, U.S. police forces and their various (counter)publics are currently engaging. This column begins with a controversial FBI report on so-called Black Identity

  5. Agreement between specific measures of adiposity and associations with high blood pressure in black South African women.

    Science.gov (United States)

    Kruger, Herculina S; Botha-Ravyse, Chrisna; Havemann-Nel, Lize; Doubell, Maretha; van Rooyen, Johannes M

    2017-11-01

    To derive percentage body fat (%BF) cut-points according to body mass index (BMI) categories for adult black South African women and to investigate the agreement between adiposity classifications according to WHO BMI and %BF cut-points. The secondary aim was to determine the association between these different adiposity measures and high blood pressure. Black women aged 29-65 years (n = 435) from Ikageng, South Africa, were included in this cross-sectional study. Socio-demographic and anthropometric data were collected (weight, height and BMI). %BF using dual-energy X-ray absorptiometry and blood pressure were measured. There was significant agreement between three %BF categories: low/normal (high blood pressure (OR = 1.75, 95% CI 1.09-2.81 versus OR = 1.92, 95% CI 1.15-3.23, respectively). Despite significant agreement between BMI and %BF categories, considerable misclassification occurred in the overweight range. Participants with excessive %BF had a greater odds of high blood pressure than those in the highest BMI category. © 2017 Wiley Periodicals, Inc.

  6. Einstein-Gauss-Bonnet metrics: black holes, black strings and a staticity theorem

    International Nuclear Information System (INIS)

    Bogdanos, C.; Charmousis, C.; Gouteraux, B.; Zegers, R.

    2009-01-01

    We find the general solution of the 6-dimensional Einstein-Gauss-Bonnet equations in a large class of space and time-dependent warped geometries. Several distinct families of solutions are found, some of which include black string metrics, space and time-dependent solutions and black holes with exotic horizons. Among these, some are shown to verify a Birkhoff type staticity theorem, although here, the usual assumption of maximal symmetry on the horizon is relaxed, allowing exotic horizon geometries. We provide explicit examples of such static exotic black holes, including ones whose horizon geometry is that of a Bergman space. We find that the situation is very different from higher-dimensional general relativity, where Einstein spaces are admissible black hole horizons and the associated black hole potential is not even affected. In Einstein-Gauss-Bonnet theory, on the contrary, the non-trivial Weyl tensor of such exotic horizons is exposed to the bulk dynamics through the higher order Gauss-Bonnet term, severely constraining the allowed horizon geometries and adding a novel charge-like parameter to the black hole potential. The latter is related to the Euler characteristic of the four-dimensional horizon and provides, in some cases, additional black hole horizons.

  7. Discrimination and Depressive Symptoms Among Black American Men: Moderated-Mediation Effects of Ethnicity and Self-Esteem.

    Science.gov (United States)

    Mereish, Ethan H; N'cho, Hammad S; Green, Carlton E; Jernigan, Maryam M; Helms, Janet E

    2016-01-01

    Discrimination is related to depression and poor self-esteem among Black men. Poorer self-esteem is also associated with depression. However, there is limited research identifying how self-esteem may mediate the associations between discrimination and depressive symptoms for disparate ethnic groups of Black men. The purpose of this study was to examine ethnic groups as a moderator of the mediating effects of self-esteem on the relationship between discrimination and depressive symptoms among a nationally representative sample of African American (n = 1201) and Afro-Caribbean American men (n = 545) in the National Survey of American Life. Due to cultural socialization differences, we hypothesized that self-esteem would mediate the associations between discrimination and depressive symptoms only for African American men, but not Afro-Caribbean American men. Moderated-mediation regression analyses indicated that the conditional indirect effects of discrimination on depressive symptoms through self-esteem were significant for African American men, but not for Afro-Caribbean men. Our results highlight important ethnic differences among Black men.

  8. HIV/AIDS prevention, faith, and spirituality among black/African American and Latino communities in the United States: strengthening scientific faith-based efforts to shift the course of the epidemic and reduce HIV-related health disparities.

    Science.gov (United States)

    Sutton, Madeline Y; Parks, Carolyn P

    2013-06-01

    Black/African American and Latino communities are disproportionately affected by the domestic HIV/AIDS epidemic. Blacks/African Americans and Latinos are also more likely to report a formal, religious, or faith affiliation when compared with non-Hispanic whites. As such, faith leaders and their institutions have been identified in the National HIV/AIDS Strategy as having a vital role to serve in reducing: (1) HIV-related health disparities and (2) the number of new HIV infections by promoting non-judgmental support for persons living with and at risk for HIV/AIDS and by serving as trusted information resources for their congregants and communities. We describe faith doctrines and faith-science partnerships that are increasing in support of faith-based HIV prevention and service delivery activities and discuss the vital role of these faith-based efforts in highly affected black/African American and Latino communities.

  9. Accreting Black Holes

    OpenAIRE

    Begelman, Mitchell C.

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these ...

  10. Naked black holes

    International Nuclear Information System (INIS)

    Horowitz, G.T.; Ross, S.F.

    1997-01-01

    It is shown that there are large static black holes for which all curvature invariants are small near the event horizon, yet any object which falls in experiences enormous tidal forces outside the horizon. These black holes are charged and near extremality, and exist in a wide class of theories including string theory. The implications for cosmic censorship and the black hole information puzzle are discussed. copyright 1997 The American Physical Society

  11. Legitimizing Blacks in Philosophy

    Directory of Open Access Journals (Sweden)

    Jameliah Shorter-Bourhanou

    2017-12-01

    Full Text Available In its efforts toward improving diversity, the discipline of philosophy has tended to focus on increasing the number of black philosophers. One crucial issue that has received less attention is the extent to which black philosophers are delegitimized in the discipline because their philosophical contributions challenge the status quo. A systematic problem that bars black philosophers from equal and full participation, this delegitimization precludes the emergence of genuine diversity and reveals the importance of interrogating broader attitudes toward black philosophical contributions. In this essay, I argue for radical systematic changes to disciplinary hallmarks of professionalization such as pedagogy, mentoring, publishing, and hiring practices with the aim of legitimizing black philosophers and their contributions.

  12. Cultivating the Genius of Black Children: Strategies to Close the Achievement Gap in the Early Years

    Science.gov (United States)

    Sullivan, Debra Ren-Etta

    2016-01-01

    There has been much attention given to the opportunity gap between white and minority students, especially African American children. Using research and years of experience "Cultivating the Genius of Black Children" is able to break down the cultural influences on learning style and provides a practical approach to helping Black children…

  13. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.

    1976-01-01

    Recent work, which has been investigating the use of the concept of entropy with respect to gravitating systems, black holes and the universe as a whole, is discussed. The resulting theory of black holes assigns a finite temperature to them -about 10 -7 K for ordinary black holes of stellar mass -which is in complete agreement with thermodynamical concepts. It is also shown that black holes must continuously emit particles just like ordinary bodies which have a certain temperature. (U.K.)

  14. Intermediate-Mass Black Holes

    Science.gov (United States)

    Miller, M. Coleman; Colbert, E. J. M.

    2004-01-01

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

  15. "Let's Do This!": Black Women Teachers' Politics and Pedagogy.

    Science.gov (United States)

    Dixson, Adrienne D.

    2003-01-01

    Examined how contemporary African American women teachers continued the tradition of political involvement, noting the extent to which issues of race, class, and gender identity informed their pedagogy and situating their activities in a black feminist activist tradition. Interviews with two elementary teachers indicated that while they did not…

  16. Rural black women's agency within intimate partnerships amid the ...

    African Journals Online (AJOL)

    The HIV pandemic reveals the contradictions between women's legal rights and the persistence of women's cultural and sexual subordination. It reflects the impact of poverty, gender roles, culture and religion. Although HIV and AIDS cuts across class, South African rural black women's infection risk seems particularly high ...

  17. The Effect of Black Peers on Black Test Scores

    Science.gov (United States)

    Armor, David J.; Duck, Stephanie

    2007-01-01

    Recent studies have used increasingly complex methodologies to estimate the effect of peer characteristics--race, poverty, and ability--on student achievement. A paper by Hanushek, Kain, and Rivkin using Texas state testing data has received particularly wide attention because it found a large negative effect of school percent black on black math…

  18. Black hole multiplicity at particle colliders (Do black holes radiate mainly on the brane?)

    International Nuclear Information System (INIS)

    Cavaglia, Marco

    2003-01-01

    If gravity becomes strong at the TeV scale, we may have the chance to produce black holes at particle colliders. In this Letter we revisit some phenomenological signatures of black hole production in TeV-gravity theories. We show that the bulk-to-brane ratio of black hole energy loss during the Hawking evaporation phase depends crucially on the black hole greybody factors and on the particle degrees of freedom. Since the greybody factors have not yet been calculated in the literature, and the particle content at trans-Planckian energies is not known, it is premature to claim that the black hole emits mainly on the brane. We also revisit the decay time and the multiplicity of the decay products of black hole evaporation. We give general formulae for black hole decay time and multiplicity. We find that the number of particles produced during the evaporation phase may be significantly lower than the average multiplicity which has been used in the past literature

  19. Trayvon Martin: Racial Profiling, Black Male Stigma, and Social Work Practice.

    Science.gov (United States)

    Teasley, Martell Lee; Schiele, Jerome H; Adams, Charles; Okilwa, Nathern S

    2018-01-01

    To address a critical gap in the social work literature, this article examines the deleterious effects of racial profiling as it pertains to police targeting of male African Americans. The authors use the Trayvon Martin court case to exemplify how racial profiling and black male stigma help perpetuate social inequality and injustice for black men. A racism-centered perspective is examined historically and contemporarily as a theoretical approach to understanding the role that race plays in social injustice through racial profiling. Implications for social work research design and practice aimed at increasing the social work knowledge base on racial profiling are discussed. The authors call for attention and advocacy by major social work organizations in the reduction of black male stigma and racial profiling. © 2017 National Association of Social Workers.

  20. Understanding the Black Aesthetic Experience.

    Science.gov (United States)

    Curtis, Marvin V.

    1988-01-01

    Discussing the importance of the Black aesthetic experience, Curtis examines Black cultural heritage and participatory style, the spiritual, and the creation and recreation of Black music. Advocating multicultural music education in teacher training, he suggests that Black music be studied for its value and contribution to society. Lists five ways…

  1. Black Writers' Views of America.

    Science.gov (United States)

    Hairston, Loyle

    1979-01-01

    This article argues that the stagnation, pessimism, and self-pity evident in recent Black writing results in part from the alienation of Black writers from the mainstream of Black life, and in part from the illusions that they share with other Blacks who have embraced the American value system. (Author/EB)

  2. Historical Dialectics of Black Nationalist Movements in America.

    Science.gov (United States)

    Turner, James E.

    1977-01-01

    The development of Africa-oriented social movements is divided into five periods: (1) the genesis of the return-to-Africa movement, 1790-1840; (2) the quest for nationality, 1845-1861; (3) the roots of Pan-Africanism, 1870-1915; (4) the Garvey movement, 1916-1930; and (5) the recent Black liberation movement, inspired by Malcolm X and operating in…

  3. String-Corrected Black Holes

    Energy Technology Data Exchange (ETDEWEB)

    Hubeny, V.

    2005-01-12

    We investigate the geometry of four dimensional black hole solutions in the presence of stringy higher curvature corrections to the low energy effective action. For certain supersymmetric two charge black holes these corrections drastically alter the causal structure of the solution, converting seemingly pathological null singularities into timelike singularities hidden behind a finite area horizon. We establish, analytically and numerically, that the string-corrected two-charge black hole metric has the same Penrose diagram as the extremal four-charge black hole. The higher derivative terms lead to another dramatic effect--the gravitational force exerted by a black hole on an inertial observer is no longer purely attractive. The magnitude of this effect is related to the size of the compactification manifold.

  4. Interracial and Intraracial Patterns of Mate Selection among America's Diverse Black Populations

    Science.gov (United States)

    Batson, Christie D.; Qian, Zhenchao; Lichter, Daniel T.

    2006-01-01

    Despite recent immigration from Africa and the Caribbean, Blacks in America are still viewed as a monolith in many previous studies. In this paper, we use newly released 2000 census data to estimate log-linear models that highlight patterns of interracial and intraracial marriage and cohabitation among African Americans, West Indians, Africans,…

  5. White theology in dialogue with Black Theology: Exploring the contribution of Klippies Kritzinger

    OpenAIRE

    George J. (Cobus) van Wyngaard

    2016-01-01

    This article explores the contribution of South African missiologist and theologian Klippies Kritzinger to a critical and anti-racist white theology. It analyses his academic work in response to Black Consciousness and Black Theology from publications during his doctoral studies, throughout the transition to democracy and into the present, where this theme remains a constant presence in his work. The article explores his use of liberation, conversation and re-evangelisation in constructing a ...

  6. African Retentions in Blues and Jazz.

    Science.gov (United States)

    Meadows, Eddie S.

    1979-01-01

    The perseverance of African musical characteristics among American Blacks is an historic reality. African retentions have been recorded in Black music of the antebellum period. Various African scales and rhythms permeate Black American music today as evidenced in the retentions found in blues and jazz. (RLV)

  7. BlackMax: A black-hole event generator with rotation, recoil, split branes, and brane tension

    International Nuclear Information System (INIS)

    Dai Dechang; Starkman, Glenn; Stojkovic, Dejan; Issever, Cigdem; Tseng, Jeff; Rizvi, Eram

    2008-01-01

    We present a comprehensive black-hole event generator, BlackMax, which simulates the experimental signatures of microscopic and Planckian black-hole production and evolution at the LHC in the context of brane world models with low-scale quantum gravity. The generator is based on phenomenologically realistic models free of serious problems that plague low-scale gravity, thus offering more realistic predictions for hadron-hadron colliders. The generator includes all of the black-hole gray-body factors known to date and incorporates the effects of black-hole rotation, splitting between the fermions, nonzero brane tension, and black-hole recoil due to Hawking radiation (although not all simultaneously). The generator can be interfaced with Herwig and Pythia. The main code can be downloaded from http://www-pnp.physics.ox.ac.uk/~issever/BlackMax/blackmax.html.

  8. Internal structure of black holes

    International Nuclear Information System (INIS)

    Cvetic, Mirjam

    2013-01-01

    Full text: We review recent progress that sheds light on the internal structure of general black holes. We first summarize properties of general multi-charged rotating black holes both in four and five dimensions. We show that the asymptotic boundary conditions of these general asymptotically flat black holes can be modified such that a conformal symmetry emerges. These subtracted geometries preserve the thermodynamic properties of the original black holes and are of the Lifshitz type, thus describing 'a black hole in the asymptotically conical box'. Recent efforts employ solution generating techniques to construct interpolating geometries between the original black hole and their subtracted geometries. Upon lift to one dimension higher, these geometries lift to AdS 3 times a sphere, and thus provide a microscopic interpretation of the black hole entropy in terms of dual two-dimensional conformal field theory. (author)

  9. Black supernovae and black holes in non-local gravity

    Energy Technology Data Exchange (ETDEWEB)

    Bambi, Cosimo [Center for Field Theory and Particle Physics and Department of Physics, Fudan University,200433 Shanghai (China); Theoretical Astrophysics, Eberhard-Karls Universität Tübingen,72076 Tübingen (Germany); Malafarina, Daniele [Department of Physics, Nazarbayev University,010000 Astana (Kazakhstan); Modesto, Leonardo [Center for Field Theory and Particle Physics and Department of Physics, Fudan University,200433 Shanghai (China)

    2016-04-22

    In a previous paper, we studied the interior solution of a collapsing body in a non-local theory of gravity super-renormalizable at the quantum level. We found that the classical singularity is replaced by a bounce, after which the body starts expanding. A black hole, strictly speaking, never forms. The gravitational collapse does not create an event horizon but only an apparent one for a finite time. In this paper, we solve the equations of motion assuming that the exterior solution is static. With such an assumption, we are able to reconstruct the solution in the whole spacetime, namely in both the exterior and interior regions. Now the gravitational collapse creates an event horizon in a finite comoving time, but the central singularity is approached in an infinite time. We argue that these black holes should be unstable, providing a link between the scenarios with and without black holes. Indeed, we find a non catastrophic ghost-instability of the metric in the exterior region. Interestingly, under certain conditions, the lifetime of our black holes exactly scales as the Hawking evaporation time.

  10. Black Sea aerosols

    International Nuclear Information System (INIS)

    Hacisalihoglu, G.; Eliyakut, F.; Anwari, M.A.; Ataman, O.Y.; Balkas, T.I.; Tuncel, G.; Olmez, I.

    1991-01-01

    Shipboard, high volume air particulate samples were collected from the Black Sea atmosphere and analyzed by instrumental neutron activation analysis, atomic absorption spectrophotometry and ion chromatography for about 40 elements and ions. Concentrations of elements in the eastern and western parts of the Black Sea are different at the 95% confidence level, with lower concentrations in the eastern Black Sea. Back-trajectories and concentrations of elements in trajectory groups show that Europe accounts for more than 70% of the anthropogenic elements in the atmosphere. The average sulfate concentration was 7 μg/m 3 , which is comparable with rural sulfate levels in western Europe. Fluxes of elements from the atmosphere to the Black Sea are in good agreement with the results of similar flux calculations for other regions

  11. The Burden of Cardiovascular Disease in Sub-Saharan Africa and the Black Diaspora.

    Science.gov (United States)

    Gillum, Richard F

    2018-03-19

    For over four decades the National Medical Association (NMA) and the Association of Black Cardiologists (ABC) have sought to bring to national attention the disparate burden of cardiovascular disease (CVD) among African Americans. However, systematic inquiry has been inadequate into the burden of CVD in the poor countries of Sub-Saharan Africa (SSA) and the African diaspora in the Americas outside the USA. However, recently, the Global Burden of Disease Study (GBD) has offered new tools for such inquiry. Several initial efforts in that direction using 2010 data have been published. This article highlights some new findings for SSA for 2016. It also suggests that NMA and ABC further this effort by direct advocacy and collaboration with the GBD to make estimates of CVD burden in African Americans and South American Blacks explicitly available in future iterations.

  12. New Directions for Black Women?

    Science.gov (United States)

    McGuigan, Dorothy, Ed.

    1978-01-01

    This collection of papers deals with various aspects of the black female experience in America. "The Black Woman in Transition" discusses the effects of sexism and racism on black women with particular reference to employment and education; it is noted that black women, in comparison with other groups in society, suffer a proportionately higher…

  13. Experiences of racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men.

    Science.gov (United States)

    Reed, E; Santana, M C; Bowleg, L; Welles, S L; Horsburgh, C R; Raj, A

    2013-04-01

    This study aimed to examine racial discrimination and relation to sexual risk for HIV among a sample of urban black and African American men. Participants of this cross-sectional study were black and African American men (N = 703) between the ages of 18 and 65 years, recruited from four urban clinical sites in the northeast. Multivariate logistic regression models were used to analyze the relation of reported racial discrimination to the following: (1) sex trade involvement, (2) recent unprotected sex, and (3) reporting a number of sex partners in the past 12 months greater than the sample average. The majority of the sample (96%) reported racial discrimination. In adjusted analyses, men reporting high levels of discrimination were significantly more likely to report recent sex trade involvement (buying and/or selling) (adjusted odds ratio (AOR) range = 1.7-2.3), having recent unprotected vaginal sex with a female partner (AOR = 1.4, 95% confidence interval (CI), 1.1-2.0), and reporting more than four sex partners in the past year (AOR = 1.4, 95% CI, 1.1-1.9). Findings highlight the link between experiences of racial discrimination and men's sexual risk for HIV.

  14. Discospondylitis caused by Staphylococcus aureus in an African black-footed penguin (Spheniscus demersus).

    Science.gov (United States)

    Field, Cara L; Beaufrère, Hugues; Wakamatsu, Nobuko; Rademacher, Nathalie; MacLean, Robert

    2012-12-01

    A 22-year-old female African black-footed penguin (Spheniscus demersus), housed indoors with other African and rockhopper penguins, was presented acutely with lethargy, ataxia, and hind limb weakness after a molt. The penguin would assume a hunched position and, when resting, sat on its hocks or lay on its keel. Physical and neurologic examination revealed hind limb paraparesis, proprioceptive deficits, and tiptoe walking. Results of a complete blood cell count and biochemical analysis revealed mild heterophilic leukocytosis, anemia, mild hypoalbuminemia, hypokalemia, and hyperuricemia. Results of whole-body radiographs and coelioscopy were unremarkable. Two computed tomographies of the spine at a 3-month interval revealed a lesion at the mobile thoracic vertebra proximal to the synsacrum with associated spinal cord compression. The penguin was treated with itraconazole, doxycycline, and meloxicam, and it initially improved with return to near normal gait and behavior. However, 5 months after the onset of clinical signs, the penguin was euthanatized after a relapse with worsening of the neurologic signs. Postmortem and histopathologic examination revealed focal granulomatous discospondylitis at the penultimate mobile thoracic vertebra, with intralesional bacteria from which Staphylococcus aureus was cultured.

  15. Black-spot poison ivy.

    Science.gov (United States)

    Schram, Sarah E; Willey, Andrea; Lee, Peter K; Bohjanen, Kimberly A; Warshaw, Erin M

    2008-01-01

    In black-spot poison ivy dermatitis, a black lacquerlike substance forms on the skin when poison ivy resin is exposed to air. Although the Toxicodendron group of plants is estimated to be the most common cause of allergic contact dermatitis in the United States, black-spot poison ivy dermatitis is relatively rare.

  16. What is black hole?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is black hole? Possible end phase of a star: A star is a massive, luminous ball of plasma having continuous nuclear burning. Star exhausts nuclear fuel →. White Dwarf, Neutron Star, Black Hole. Black hole's gravitational field is so powerful that even ...

  17. Genocide and Black Ecology

    Science.gov (United States)

    Sinnette, Calvin H.

    1972-01-01

    Contends that the survival of black people is in serious jeopardy as is evidenced in contemporary discussions on the worldwide plight of black people, and that an exhaustive study of the problem in its many dimensions is seriously lacking; the moral and ethical issues of genocide require examination from a black perspective. (JW)

  18. Quantum effects in black holes

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1979-01-01

    A strict definition of black holes is presented and some properties with regard to their mass are enumerated. The Hawking quantum effect - the effect of vacuum instability in the black hole gravitational field, as a result of shich the black hole radiates as a heated body is analyzed. It is shown that in order to obtain results on the black hole radiation it is sufficient to predetermine the in-vacuum state at a time moment in the past, when the collapsing body has a large size, and its gravitational field can be neglected. The causes and the place of particle production by the black hole, and also the space-time inside the black hole, are considered

  19. Reconceptualizing successful aging among black women and the relevance of the strong black woman archetype.

    Science.gov (United States)

    Baker, Tamara A; Buchanan, NiCole T; Mingo, Chivon A; Roker, Rosalyn; Brown, Candace S

    2015-02-01

    Although there are multiple pathways to successful aging, little is known of what it means to age successfully among black women. There is a growing body of literature suggesting that black women experience a number of social challenges (sexism and racism) that may present as barriers to aging successfully. Applying aspects of the Strong Black Women ideal, into theoretical concepts of successful aging, may be particularly relevant in understanding which factors impair or promote the ability of black women to age successfully. The Strong Black Women archetype is a culturally salient ideal prescribing that black women render a guise of self-reliance, selflessness, and psychological, emotional, and physical strength. Although this ideal has received considerable attention in the behavioral sciences, it has been largely absent within the gerontology field. Nevertheless, understanding the dynamics of this cultural ideal may enhance our knowledge while developing an appreciation of the black woman's ability to age successfully. Rather than summarize the social, physical, and mental health literature focusing on health outcomes of black women, this conceptual review examines the Strong Black Women archetype and its application to the lived experiences of black women and contributions to current theories of successful aging. Focusing on successful aging exclusively among black women enhances our understanding of this group by considering their identity as women of color while recognizing factors that dictate their ability to age successfully. © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Carbon black vs. black carbon and other airborne materials containing elemental carbon: Physical and chemical distinctions

    International Nuclear Information System (INIS)

    Long, Christopher M.; Nascarella, Marc A.; Valberg, Peter A.

    2013-01-01

    Airborne particles containing elemental carbon (EC) are currently at the forefront of scientific and regulatory scrutiny, including black carbon, carbon black, and engineered carbon-based nanomaterials, e.g., carbon nanotubes, fullerenes, and graphene. Scientists and regulators sometimes group these EC-containing particles together, for example, interchangeably using the terms carbon black and black carbon despite one being a manufactured product with well-controlled properties and the other being an undesired, incomplete-combustion byproduct with diverse properties. In this critical review, we synthesize information on the contrasting properties of EC-containing particles in order to highlight significant differences that can affect hazard potential. We demonstrate why carbon black should not be considered a model particle representative of either combustion soots or engineered carbon-based nanomaterials. Overall, scientific studies need to distinguish these highly different EC-containing particles with care and precision so as to forestall unwarranted extrapolation of properties, hazard potential, and study conclusions from one material to another. -- Highlights: •Major classes of elemental carbon-containing particles have distinct properties. •Despite similar names, carbon black should not be confused with black carbon. •Carbon black is distinguished by a high EC content and well-controlled properties. •Black carbon particles are characterized by their heterogenous properties. •Carbon black is not a model particle representative of engineered nanomaterials. -- This review demonstrates the significant physical and chemical distinctions between elemental carbon-containing particles e.g., carbon black, black carbon, and engineered nanomaterials

  1. The angry black woman: the impact of pejorative stereotypes on psychotherapy with black women.

    Science.gov (United States)

    Ashley, Wendy

    2014-01-01

    In the aftermath of slavery and the resulting social, economic, and political effects, Black women have become the victims of negative stereotyping in mainstream American culture. Such stereotypes include the myth of the angry Black woman that characterizes these women as aggressive, ill tempered, illogical, overbearing, hostile, and ignorant without provocation. Symptoms presented by Black women during mental health treatment may reinforce this myth. However, many of the negative characteristics of the angry Black woman developed in response to external stressors and historical factors. Black women also have a unique experience with and expressions of anger that shape the presenting symptoms interpreted by the mental health clinician. This myth and corresponding negative stereotypes significantly affect Black women intrapsychically, interpersonally, and are likely to influence the efficacy of mental health treatment. Understanding and treatment of Black women in a mental health context should be influenced by the cultural norms and sociopolitical dynamics affecting these clients. Successful mental health treatment requires cultural competence and clinicians who are well prepared to navigate the inherent complexities of culture with clients. Awareness of the angry Black woman mythology, including its genesis, manifestations, and the unique experiences of Black women, may raise the standards of cultural competence for clinicians and provide more successful treatment outcomes in working with this population. A case example illustrates the assiduity essential to practicing in a culturally competent manner. A client is presented from a traditional psychotherapeutic perspective and then viewed through a lens that integrates psychotherapeutic practice with conscious awareness of the mythology and stereotypes impacting Black women. Implications for culturally relevant practice are discussed.

  2. Over spinning a black hole?

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam; Cardoso, Vitor; Nerozzi, Andrea; Rocha, Jorge V, E-mail: mariam.bouhmadi@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt, E-mail: andrea.nerozzi@ist.utl.pt, E-mail: jorge.v.rocha@ist.utl.pt [CENTRA, Department de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

    2011-09-22

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for black holes in higher dimensions. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.

  3. Adaptability of black walnut, black cherry, and Northern red oak to Northern California

    Science.gov (United States)

    Philip M. McDonald

    1987-01-01

    When planted in sheltered sites in northern California, only 49% of black walnut (Juglans nigra L.) and 58% of black cherry (Prunus serotina Ehrh.) survived for 15 years, and 20% of northern red oak (Quercus rubra L.) survived for 10 years. The black walnut trees averaged 0.6 inches diameter at breast...

  4. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.

    2008-09-01

    Full Text Available We review black-hole solutions of higher-dimensional vacuum gravity and higher-dimensional supergravity theories. The discussion of vacuum gravity is pedagogical, with detailed reviews of Myers–Perry solutions, black rings, and solution-generating techniques. We discuss black-hole solutions of maximal supergravity theories, including black holes in anti-de Sitter space. General results and open problems are discussed throughout.

  5. Vital Signs: Racial Disparities in Age-Specific Mortality Among Blacks or African Americans - United States, 1999-2015.

    Science.gov (United States)

    Cunningham, Timothy J; Croft, Janet B; Liu, Yong; Lu, Hua; Eke, Paul I; Giles, Wayne H

    2017-05-05

    Although the overall life expectancy at birth has increased for both blacks and whites and the gap between these populations has narrowed, disparities in life expectancy and the leading causes of death for blacks compared with whites in the United States remain substantial. Understanding how factors that influence these disparities vary across the life span might enhance the targeting of appropriate interventions. Trends during 1999-2015 in mortality rates for the leading causes of death were examined by black and white race and age group. Multiple 2014 and 2015 national data sources were analyzed to compare blacks with whites in selected age groups by sociodemographic characteristics, self-reported health behaviors, health-related quality of life indicators, use of health services, and chronic conditions. During 1999-2015, age-adjusted death rates decreased significantly in both populations, with rates declining more sharply among blacks for most leading causes of death. Thus, the disparity gap in all-cause mortality rates narrowed from 33% in 1999 to 16% in 2015. However, during 2015, blacks still had higher death rates than whites for all-cause mortality in all groups aged blacks in age groups deaths among blacks (especially cardiovascular disease and cancer and their risk factors) across the life span and create equal opportunities for health.

  6. Black hole decay as geodesic motion

    International Nuclear Information System (INIS)

    Gupta, Kumar S.; Sen, Siddhartha

    2003-01-01

    We show that a formalism for analyzing the near-horizon conformal symmetry of Schwarzschild black holes using a scalar field probe is capable of describing black hole decay. The equation governing black hole decay can be identified as the geodesic equation in the space of black hole masses. This provides a novel geometric interpretation for the decay of black holes. Moreover, this approach predicts a precise correction term to the usual expression for the decay rate of black holes

  7. Black report up-date

    International Nuclear Information System (INIS)

    1988-12-01

    In 1984, the Black Report published its results on the incidence of cancer and leukaemia in under 25-year olds in the village of Seascale and the surrounding area near the Sellafield nuclear reprocessing plant. Since then the pressure group core, as a result of their own independent research, has discovered ten additional cases of childhood cancer which should have been included in the Black Report and a Further two cases since the Black Report was written. This represents an additional 31% over the initial numbers considered and a review of the Black Report is sought. (UK)

  8. [Mixed connective tissue disease: prevalence and clinical characteristics in African black, study of 7 cases in Gabon and review of the literature].

    Science.gov (United States)

    Missounga, Landry; Ba, Josaphat Iba; Nseng Nseng Ondo, Ingrid Rosalie; Nziengui Madjinou, Maria Ines Carine; Malekou, Doris; Mouendou Mouloungui, Emeline Gracia; Nzengue, Emmanuel Ecke; Boguikouma, Jean Bruno; Kombila, Moussavou

    2017-01-01

    The literature reports that mixed connective tissue disease seems more frequent in the black population and among Asians. This study aims to determine the prevalence of mixed connective tissue disease (MCTD) among connective tissue disorders and all rheumatologic pathologies in a hospital population in Gabon as well as to describe the clinical features of this disease. We conducted a retrospective study by reviewing the medical records of patients treated for mixed connective tissue disease (Kasukawa criteria) and other entities of connective tissue disorders (ACR criteria) in the Division of Rheumatology at the University Hospital in Libreville between January 2010 and December 2015. For each case of MCTD the parameters studied were articular and extra-articular manifestations, anti-U1RNP antibodies levels, patient's evolution. Over a period of 6 years, data were collected by medical records of 7 patients out of 6050 patients and 67 cases of connective tissue disorders, reflecting a prevalence of 0.11% and 10.44% respectively. the 7 patients were women (100%), with an average age of 39.5 years. Articular manifestations included: polyarthritis, myalgias, chubby fingers and Raynaud's phenomenon in 87.5%, 87.5%, 28.6% and 14% respectively. The 7 patients had high anti-U1RNP antibodies levels, ranging between 5 and 35N (N≤ 7 IU). A case of death due to pulmonary arterial hypertension (PAH) was certified. This is the largest case series of MCTD reported in Black Africa. The disease seems to be rare among the black Africans; the reason could be genetic. The demographic and clinical aspects appear similar to those in Caucasians, Asians and Blacks except for a low frequency of Raynaud?s phenomenon among Blacks.

  9. Secondary sexual characteristics of stunted and non-stunted black ...

    African Journals Online (AJOL)

    It is known that sexual maturation is dependent on genetic and environmental factors and socio-economic status. The purpose of this study was to describe secondary sexual characteristics of stunted and non-stunted black South African boys from a low socio-economic status living in a township in the North West Province.

  10. Lifshitz topological black holes

    International Nuclear Information System (INIS)

    Mann, R.B.

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  11. Differing patterns of brain structural abnormalities between black and white patients with their first episode of psychosis.

    LENUS (Irish Health Repository)

    Morgan, K D

    2010-07-01

    African-Caribbean and black African people living in the UK are reported to have a higher incidence of diagnosed psychosis compared with white British people. It has been argued that this may be a consequence of misdiagnosis. If this is true they might be less likely to show the patterns of structural brain abnormalities reported in white British patients. The aim of this study therefore was to investigate whether there are differences in the prevalence of structural brain abnormalities in white and black first-episode psychosis patients.

  12. Gender and Ethnic Differences in the Association Between Body Image Dissatisfaction and Binge Eating Disorder among Blacks.

    Science.gov (United States)

    Blostein, Freida; Assari, Shervin; Caldwell, Cleopatra Howard

    2017-08-01

    The research on binge eating has overwhelmingly focused on Whites. We aimed to study gender and ethnic differences in the association between body image dissatisfaction and binge eating in a nationally representative sample of Black adults in the USA. This cross-sectional study used data from the National Survey of American Life (NSAL), 2003-2004. Self-identified Caribbean Black (n = 1621) and African American (3570) adults aged 18 and older were enrolled. The independent variable was body dissatisfaction measured with two items. Using the World Health Organization Composite International Diagnostic Interview (WHO-CIDI), outcome was lifetime binge eating without hierarchy according to the DSM-IV criteria. Covariates included age, socioeconomic factors (i.e., education and marital status), and body mass index. Ethnicity and gender were focal moderators. Logistic regressions were used for data analysis. Despite comparable prevalence of lifetime binge eating (5 vs 4 %, p > 0.05), African Americans reported higher body image dissatisfaction than Caribbean Blacks (36 vs 29 %, p > 0.05). In the pooled sample, body dissatisfaction was a strong predictor of lifetime binge eating disorders. There was a significant interaction (p = 0.039) between ethnicity and body image dissatisfaction on binge eating, suggesting a stronger association between body image dissatisfaction and lifetime binge eating for Caribbean Blacks (OR = 11.65, 95 % 6.89-19.72) than African Americans (OR = 6.72, 95 % CI 3.97-11.37). Gender did not interact with body image dissatisfaction on binge eating. Ethnic variation in the link between body image dissatisfaction and binge eating may be due to within-race cultural differences in body image between African Americans and Caribbean Blacks. This may include different definitions, norms, and expectations regarding the body size. Findings suggest that ethnicity may bias relevance of body image dissatisfaction as a diagnostic criterion for

  13. Acceleration of black hole universe

    Science.gov (United States)

    Zhang, T. X.; Frederick, C.

    2014-01-01

    Recently, Zhang slightly modified the standard big bang theory and developed a new cosmological model called black hole universe, which is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain all observations of the universe. Previous studies accounted for the origin, structure, evolution, expansion, and cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This paper investigates acceleration of the black hole universe and provides an alternative explanation for the redshift and luminosity distance measurements of type Ia supernovae. The results indicate that the black hole universe accelerates its expansion when it accretes the ambient matter in an increasing rate. In other words, i.e., when the second-order derivative of the mass of the black hole universe with respect to the time is positive . For a constant deceleration parameter , we can perfectly explain the type Ia supernova measurements with the reduced chi-square to be very close to unity, χ red˜1.0012. The expansion and acceleration of black hole universe are driven by external energy.

  14. Socio-Demographic and Lifestyle Factors Predict 5-Year Changes in Adiposity among a Group of Black South African Adults

    Directory of Open Access Journals (Sweden)

    Cornelie Nienaber-Rousseau

    2017-09-01

    Full Text Available The rising prevalence of obesity and excessive adiposity are global public health concerns. Understanding determinants of changes in adiposity over time is critical for informing effective evidence-based prevention or treatment. However, limited information is available to achieve this objective. Cultural, demographic, environmental, and behavioral factors including socio-economic status (SES likely account for obesity development. To this end, we related these variables to anthropometric measures in 1058 black adult Tswana-speaking South Africans who were HIV negative in a prospective study over five years. Body mass index (BMI and waist circumference increased in both sexes, whereas triceps skinfold thickness remained the same. Over the five years, women moved to higher BMI categories and more were diagnosed with central obesity. Age correlated negatively, whereas SES, physical activity, energy, and fat intake correlated positively with adiposity markers in women. In men, SES, marital status, physical activity, and being urban predicted increases in adiposity. For women, SES and urbanicity increased, whereas menopause and smoking decreased adiposity. Among men, smokers had less change in BMI than those that never smoked over five years. Our findings suggest that interventions, focusing on the urban living, the married and those with the highest SES—the high-risk groups identified herein—are of primary importance to contain morbidity and premature mortality due to obesity in black South Africans.

  15. Selection, Language Heritage, and the Earnings Trajectories of Black Immigrants in the United States

    Science.gov (United States)

    Hamilton, Tod G.

    2014-01-01

    Research suggests that immigrants from the English-speaking Caribbean surpass the earnings of U.S.-born blacks approximately one decade after arriving in the United States. Using data from the 1980–2000 U.S. censuses and the 2005–2007 American Community Surveys on U.S.-born black and non-Hispanic white men as well as black immigrant men from all the major sending regions of the world, I evaluate whether selective migration and language heritage of immigrants’ birth countries account for the documented earnings crossover. I validate the earnings pattern of black immigrants documented in previous studies, but I also find that the earnings of most arrival cohorts of immigrants from the English-speaking Caribbean, after residing in the United States for more than 20 years, are projected to converge with or slightly overtake those of U.S.-born black internal migrants. The findings also show three arrival cohorts of black immigrants from English-speaking African countries are projected to surpass the earnings of U.S.-born black internal migrants. No arrival cohort of black immigrants is projected to surpass the earnings of U.S.-born non-Hispanic whites. Birth-region analysis shows that black immigrants from English-speaking countries experience more rapid earnings growth than immigrants from non-English-speaking countries. The arrival-cohort and birth-region variation in earnings documented in this study suggest that selective migration and language heritage of black immigrants’ birth countries are important determinants of their initial earnings and earnings trajectories in the United States. PMID:24854004

  16. Why Blue-Collar Blacks Help Less

    OpenAIRE

    Smith, Sandra Susan; Young, Kara Alexis

    2013-01-01

    Why are blue-collar blacks less likely to help jobseekers than jobholders from other ethnoracial groups or even than more affluent blacks? Drawing from in-depth, semi-structured interviews with 97 black and Latino workers at one large, public sector employer, we find that blue-collar black workers both helped less proactively and rejected more requests for assistance than did blue-collar Latino and white-collar black workers. We attribute blue-collar blacks’ more passive engagement to their...

  17. Curvature invariant characterization of event horizons of four-dimensional black holes conformal to stationary black holes

    Science.gov (United States)

    McNutt, David D.

    2017-11-01

    We introduce three approaches to generate curvature invariants that transform covariantly under a conformal transformation of a four-dimensional spacetime. For any black hole conformally related to a stationary black hole, we show how a set of conformally covariant invariants can be combined to produce a conformally covariant invariant that detects the event horizon of the conformally related black hole. As an application we consider the rotating dynamical black holes conformally related to the Kerr-Newman-Unti-Tamburino-(anti)-de Sitter spacetimes and construct an invariant that detects the conformal Killing horizon along with a second invariant that detects the conformal stationary limit surface. In addition, we present necessary conditions for a dynamical black hole to be conformally related to a stationary black hole and apply these conditions to the ingoing Kerr-Vaidya and Vaidya black hole solutions to determine if they are conformally related to stationary black holes for particular choices of the mass function. While two of the three approaches cannot be generalized to higher dimensions, we discuss the existence of a conformally covariant invariant that will detect the event horizon for any higher dimensional black hole conformally related to a stationary black hole which admits at least two conformally covariant invariants, including all vacuum spacetimes.

  18. New geometries for black hole horizons

    Energy Technology Data Exchange (ETDEWEB)

    Armas, Jay [Physique Théorique et Mathématique,Université Libre de Bruxelles and International Solvay Institutes, ULB-Campus Plaine CP231, B-1050 Brussels (Belgium); Blau, Matthias [Albert Einstein Center for Fundamental Physics, University of Bern,Sidlerstrasse 5, 3012 Bern (Switzerland)

    2015-07-10

    We construct several classes of worldvolume effective actions for black holes by integrating out spatial sections of the worldvolume geometry of asymptotically flat black branes. This provides a generalisation of the blackfold approach for higher-dimensional black holes and yields a map between different effective theories, which we exploit by obtaining new hydrodynamic and elastic transport coefficients via simple integrations. Using Euclidean minimal surfaces in order to decouple the fluid dynamics on different sections of the worldvolume, we obtain local effective theories for ultraspinning Myers-Perry branes and helicoidal black branes, described in terms of a stress-energy tensor, particle currents and non-trivial boost vectors. We then study in detail and present novel compact and non-compact geometries for black hole horizons in higher-dimensional asymptotically flat space-time. These include doubly-spinning black rings, black helicoids and helicoidal p-branes as well as helicoidal black rings and helicoidal black tori in D≥6.

  19. Unforgivable Blackness: Visual Rhetoric, Reader Response, and Critical Racial Literacy

    Science.gov (United States)

    Gardner, Roberta Price

    2017-01-01

    Perceptions of black representations in literature and other visual mediums as positive or negative continuously cause consternation and debate (Fleetwood, 2011). Because African American children are literacy participants and consumers, they are not immune from experiencing this tension. This essay considers the effects and affective threads of…

  20. Statistical mechanics of black holes

    International Nuclear Information System (INIS)

    Harms, B.; Leblanc, Y.

    1992-01-01

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black-hole decay and of quantum coherence are also addressed

  1. Few-layer black phosphorus nanoparticles.

    Science.gov (United States)

    Sofer, Zdenek; Bouša, Daniel; Luxa, Jan; Mazanek, Vlastimil; Pumera, Martin

    2016-01-28

    Herein, black phosphorus quantum dots and nanoparticles of a few layer thickness were prepared and characterized using STEM, AFM, dynamic light scattering, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and photoluminescence. Impact electrochemistry of the induvidual black phosphorus nanoparticles allows their size determination. The centrifugation of colloidal black phosphorus nanoparticles allowed separation of quantum dots with sizes up to 15 nm. These black phosphorus nanoparticles exhibit a large band gap and are expected to find a wide range of applications from semiconductors to biomolecule tags. The use of black phosphorus nanoparticles for vapour sensing was successfully demonstrated.

  2. Boundary Spanners and Advocacy Leaders: Black Educators and Race Equality Work in Toronto and London, 1968-1995

    Science.gov (United States)

    Johnson, Lauri

    2016-01-01

    This comparative study examines the historical development of race equality efforts during the 1970s and 1980s in two global cities--Toronto and London--and the role of African Canadian and Black British educators in longstanding school-community partnerships. I characterize the leadership stance of Black educators as boundary spanners and…

  3. The State of Black Education: The Politics of Educating African American Students at Colleges and Universities

    Directory of Open Access Journals (Sweden)

    Earnest N. Bracey, Ph.D.

    2014-03-01

    Full Text Available In terms of higher education for African American students, the “school-to-prison pipeline” or Prison Industrial Complex must be totally dismantled in order to focus entirely on academic performance at colleges and universities and HBCUs. Additionally, mentors should be identified to tutor and guide and help black youngsters overcome their fear of learning and going to school, so that our whole society can benefit and improve academically. Finally, in this respect, we-the-people can move our nation forward by graduating people of color at higher institutions of learning, while providing them with a more productive life, and social advancement.

  4. Black women talk about workplace stress and how they cope.

    Science.gov (United States)

    Hall, J Camille; Everett, Joyce E; Hamilton-Mason, Johnnie

    2012-01-01

    Black women face the same struggles as White women; however, they have to face issues of diversity on top of inequality. The purpose of this study was to explore work-related stressors that affect the lives of Black women and how they cope with them. Using an exploratory design with grounded-theory methods, five basic themes emerged that identify when racism and sexism are experienced as stressors for African American women in the workplace. The themes are: (1) being hired or promoted in the workplace, (2) defending one’s race and lack of mentorship, (3) shifting or code switching to overcome barriers to employment, (4) coping with racism and discrimination, and (5) being isolated and/or excluded. The results from this study indicate African American women use emotion- and problem-focused coping responses to manage stress (e.g., racism and sexism) in the workplace. The article concludes with a discussion of practice implications of these findings.

  5. Regular black hole in three dimensions

    OpenAIRE

    Myung, Yun Soo; Yoon, Myungseok

    2008-01-01

    We find a new black hole in three dimensional anti-de Sitter space by introducing an anisotropic perfect fluid inspired by the noncommutative black hole. This is a regular black hole with two horizons. We compare thermodynamics of this black hole with that of non-rotating BTZ black hole. The first-law of thermodynamics is not compatible with the Bekenstein-Hawking entropy.

  6. National Black HIV/AIDS Awareness Day

    Centers for Disease Control (CDC) Podcasts

    2012-02-01

    In observance of National Black HIV/AIDS Awareness Day, Dr. Kevin Fenton, Director of CDC’s National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, talks about the HIV/AIDS among African Americans and what steps can be taken on the national, state, local, and individual levels to address this epidemic.  Created: 2/1/2012 by National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (NCHHSTP).   Date Released: 2/1/2012.

  7. Boosted quantum black hole and black string in M-theory, and quantum correction to Gregory-Laflamme instability

    Energy Technology Data Exchange (ETDEWEB)

    Hyakutake, Yoshifumi [Faculty of Science, Ibaraki University,Bunkyo 2-1-1, Mito, Ibaraki, 310-8512 (Japan)

    2015-09-11

    We take into account higher derivative R{sup 4} corrections in M-theory and construct quantum black hole and black string solutions in 11 dimensions up to the next leading order. The quantum black string is stretching along the 11th direction and the Gregory-Laflamme instability is examined at the quantum level. Thermodynamics of the boosted quantum black hole and black string are also discussed. Especially we take the near horizon limit of the quantum black string and investigate its instability quantitatively.

  8. Stationary black holes: large D analysis

    International Nuclear Information System (INIS)

    Suzuki, Ryotaku; Tanabe, Kentaro

    2015-01-01

    We consider the effective theory of large D stationary black holes. By solving the Einstein equations with a cosmological constant using the 1/D expansion in near zone of the black hole we obtain the effective equation for the stationary black hole. The effective equation describes the Myers-Perry black hole, bumpy black holes and, possibly, the black ring solution as its solutions. In this effective theory the black hole is represented as an embedded membrane in the background, e.g., Minkowski or Anti-de Sitter spacetime and its mean curvature is given by the surface gravity redshifted by the background gravitational field and the local Lorentz boost. The local Lorentz boost property of the effective equation is observed also in the metric itself. In fact we show that the leading order metric of the Einstein equation in the 1/D expansion is generically regarded as a Lorentz boosted Schwarzschild black hole. We apply this Lorentz boost property of the stationary black hole solution to solve perturbation equations. As a result we obtain an analytic formula for quasinormal modes of the singly rotating Myers-Perry black hole in the 1/D expansion.

  9. Some factors in condom use amongst first-year Nigerian University students and black and white South Africans.

    Science.gov (United States)

    Peltzer, Karl; Oladimeji, Yetunde

    2004-04-01

    A questionnaire was administered to 213 sexually active first-year Nigerian university students and 150 Black and 150 White South African adults. Nigerian students gave 90% correct answers on 6 of the 10 items of a measure of condom knowledge (M = 6.1). The most common mistakes with respect to condom use were ignorance about putting a condom on just before ejaculation (37%), the use of an oil-based lubricant with a condom (29%), and when to take off a condom (28%). For the South African sample utility of the Health Belief Model and Theory of Reasoned Action for HIV prevention could be confirmed by intention to use condoms. Race and preventive benefits were predictive for current condom use. Findings have relevant implications for developing culturally diverse HIV intervention programs if confirmed with larger diverse groups.

  10. Black branes as piezoelectrics.

    Science.gov (United States)

    Armas, Jay; Gath, Jakob; Obers, Niels A

    2012-12-14

    We find a realization of linear electroelasticity theory in gravitational physics by uncovering a new response coefficient of charged black branes, exhibiting their piezoelectric behavior. Taking charged dilatonic black strings as an example and using the blackfold approach we measure their elastic and piezolectric moduli. We also use our results to draw predictions about the equilibrium condition of charged dilatonic black rings in dimensions higher than six.

  11. High prevalence of primary dyslipidaemia in black South African ...

    African Journals Online (AJOL)

    In South Africa (SA), premature deaths due to heart and blood vessel diseases in people of working age (35 - 64 years) have been predicted to increase by 41% between 2007 ... To assess the burden and prevalence of dyslipidaemia in the SA black population at Dr George Mukhari Hospital in the north region of Gauteng.

  12. Black hole levitron

    NARCIS (Netherlands)

    Arsiwalla, X.D.; Verlinde, E.P.

    2010-01-01

    We study the problem of spatially stabilizing four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes placed in external fields we find that taking a continuum limit of Denef et al.’s multicenter

  13. Black Hole Grabs Starry Snack

    Science.gov (United States)

    2006-01-01

    [figure removed for brevity, see original site] Poster Version This artist's concept shows a supermassive black hole at the center of a remote galaxy digesting the remnants of a star. NASA's Galaxy Evolution Explorer had a 'ringside' seat for this feeding frenzy, using its ultraviolet eyes to study the process from beginning to end. The artist's concept chronicles the star being ripped apart and swallowed by the cosmic beast over time. First, the intact sun-like star (left) ventures too close to the black hole, and its own self-gravity is overwhelmed by the black hole's gravity. The star then stretches apart (middle yellow blob) and eventually breaks into stellar crumbs, some of which swirl into the black hole (cloudy ring at right). This doomed material heats up and radiates light, including ultraviolet light, before disappearing forever into the black hole. The Galaxy Evolution Explorer was able to watch this process unfold by observing changes in ultraviolet light. The area around the black hole appears warped because the gravity of the black hole acts like a lens, twisting and distorting light.

  14. A nonsingular rotating black hole

    International Nuclear Information System (INIS)

    Ghosh, Sushant G.

    2015-01-01

    The spacetime singularities in classical general relativity are inevitable, as predicated by the celebrated singularity theorems. However, it is a general belief that singularities do not exist in Nature and that they are the limitations of the general relativity. In the absence of a welldefined quantum gravity, models of regular black holes have been studied. We employ a probability distribution inspired mass function m(r) to replace the Kerr black hole mass M to represent a nonsingular rotating black hole that is identified asymptotically (r >> k, k > 0 constant) exactly as the Kerr-Newman black hole, and as the Kerr black hole when k = 0. The radiating counterpart renders a nonsingular generalization of Carmeli's spacetime as well as Vaidya's spacetime, in the appropriate limits. The exponential correction factor changing the geometry of the classical black hole to remove the curvature singularity can also be motivated by quantum arguments. The regular rotating spacetime can also be understood as a black hole of general relativity coupled to nonlinear electrodynamics. (orig.)

  15. Thermodynamic theory of black holes

    Energy Technology Data Exchange (ETDEWEB)

    Davies, P C.W. [King' s Coll., London (UK). Dept. of Mathematics

    1977-04-21

    The thermodynamic theory underlying black hole processes is developed in detail and applied to model systems. It is found that Kerr-Newman black holes undergo a phase transition at a = 0.68M or Q = 0.86M, where the heat capacity has an infinite discontinuity. Above the transition values the specific heat is positive, permitting isothermal equilibrium with a surrounding heat bath. Simple processes and stability criteria for various black hole situations are investigated. The limits for entropically favoured black hole formation are found. The Nernst conditions for the third law of thermodynamics are not satisfied fully for black holes. There is no obvious thermodynamic reason why a black hole may not be cooled down below absolute zero and converted into a naked singularity. Quantum energy-momentum tensor calculations for uncharged black holes are extended to the Reissner-Nordstrom case, and found to be fully consistent with the thermodynamic picture for Q < M. For Q < M the model predicts that 'naked' collapse also produces radiation, with such intensity that the collapsing matter is entirely evaporated away before a naked singularity can form.

  16. ‘My child did not like using sun protection’: practices and perceptions of child sun protection among rural black African mothers

    OpenAIRE

    Zamantimande Kunene; Patricia N. Albers; Robyn M. Lucas; Cathy Banwell; Angela Mathee; Caradee Y. Wright

    2017-01-01

    Abstract Background Photodamage is partially mitigated by darker skin pigmentation, but immune suppression, photoaging and cataracts occur among individuals with all skin types. Methods To assess practices and acceptability to Black African mothers of sun protection equipment for their children living in a rural area, participants were recruited at the time of their child’s 18-month vaccinations. Mothers completed a baseline questionnaire on usual sun behaviours and sun protection practices. ...

  17. NASA Observatory Confirms Black Hole Limits

    Science.gov (United States)

    2005-02-01

    The very largest black holes reach a certain point and then grow no more, according to the best survey to date of black holes made with NASA's Chandra X-ray Observatory. Scientists have also discovered many previously hidden black holes that are well below their weight limit. These new results corroborate recent theoretical work about how black holes and galaxies grow. The biggest black holes, those with at least 100 million times the mass of the Sun, ate voraciously during the early Universe. Nearly all of them ran out of 'food' billions of years ago and went onto a forced starvation diet. Focus on Black Holes in the Chandra Deep Field North Focus on Black Holes in the Chandra Deep Field North On the other hand, black holes between about 10 and 100 million solar masses followed a more controlled eating plan. Because they took smaller portions of their meals of gas and dust, they continue growing today. "Our data show that some supermassive black holes seem to binge, while others prefer to graze", said Amy Barger of the University of Wisconsin in Madison and the University of Hawaii, lead author of the paper describing the results in the latest issue of The Astronomical Journal (Feb 2005). "We now understand better than ever before how supermassive black holes grow." One revelation is that there is a strong connection between the growth of black holes and the birth of stars. Previously, astronomers had done careful studies of the birthrate of stars in galaxies, but didn't know as much about the black holes at their centers. DSS Optical Image of Lockman Hole DSS Optical Image of Lockman Hole "These galaxies lose material into their central black holes at the same time that they make their stars," said Barger. "So whatever mechanism governs star formation in galaxies also governs black hole growth." Astronomers have made an accurate census of both the biggest, active black holes in the distance, and the relatively smaller, calmer ones closer by. Now, for the first

  18. Erratic Black Hole Regulates Itself

    Science.gov (United States)

    2009-03-01

    New results from NASA's Chandra X-ray Observatory have made a major advance in explaining how a special class of black holes may shut off the high-speed jets they produce. These results suggest that these black holes have a mechanism for regulating the rate at which they grow. Black holes come in many sizes: the supermassive ones, including those in quasars, which weigh in at millions to billions of times the mass of the Sun, and the much smaller stellar-mass black holes which have measured masses in the range of about 7 to 25 times the Sun's mass. Some stellar-mass black holes launch powerful jets of particles and radiation, like seen in quasars, and are called "micro-quasars". The new study looks at a famous micro-quasar in our own Galaxy, and regions close to its event horizon, or point of no return. This system, GRS 1915+105 (GRS 1915 for short), contains a black hole about 14 times the mass of the Sun that is feeding off material from a nearby companion star. As the material swirls toward the black hole, an accretion disk forms. This system shows remarkably unpredictable and complicated variability ranging from timescales of seconds to months, including 14 different patterns of variation. These variations are caused by a poorly understood connection between the disk and the radio jet seen in GRS 1915. Chandra, with its spectrograph, has observed GRS 1915 eleven times since its launch in 1999. These studies reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole. The wind is believed to shut down the jet by depriving it of matter that would have otherwise fueled it. Conversely, once the wind dies down, the jet can re-emerge. "We think the jet and wind around this black hole are in a sort of tug of war," said Joseph Neilsen, Harvard graduate student and lead author of the paper appearing in the journal Nature. "Sometimes one is winning and then, for reasons we don

  19. Atypical features of hyperthyroidism in Blacks

    International Nuclear Information System (INIS)

    Kalk, W.J.

    1980-01-01

    Hyperthyroidism is reportedly uncommon in the indigenous populations of Africa. The presenting symptoms volunteered, the symptoms elicited by direct questioning, and the results of physical examination were therefore prospectively compared in 60 Black and 56 White patients with thyrotoxicosis attending a single thyroid clinic. Fewer Blacks than Whites volunteered information about weight loss, while more Blacks complained only of the presence of a goitre. A 'chance' diagnosis of hyperthyroidism was made more frequently in Blacks. Symptomatology elicited by direct questioning and findings on physical examination were generally similar in each group, except that Blacks presented more frequently with complicated disease (cardiac failure and overt myopathy) and infiltrative ophthalmopathy. The frequency with which hyperthyroidism presents 'atypically' in Black compared with White patients may reflect educational, socio-economic and cultural differences in the Black and White populations, and may partly explain the infrequency with which this disease is diagnosed in Blacks

  20. The association of perceived stress, contextualized stress, and emotional eating with body mass index in college-aged Black women.

    Science.gov (United States)

    Diggins, Allyson; Woods-Giscombe, Cheryl; Waters, Sandra

    2015-12-01

    A growing body of literature supports the association between adverse stress experiences and health inequities, including obesity, among African American/Black women. Adverse stress experiences can contribute to poor appetite regulation, increased food intake, emotional eating, binge eating, and sedentary behavior, all of which can contribute to weight gain and obesity. Most research studies concerning the effect of psychological stress on eating behaviors have not examined the unique stress experience, body composition, and eating behaviors of African American/Black women. Even fewer studies have examined these constructs among Black female college students, who have an increased prevalence of overweight and obesity compared to their counterparts. Therefore, the aim of the current study is to examine the associations among emotional eating, perceived stress, contextualized stress, and BMI in African American female college students. All participants identified as African American or Black (N=99). The mean age of the sample was 19.4 years (SD=1.80). A statistically significant eating behavior patterns×perceived stress interaction was evident for body mass index (BMI) (β=0.036, S.E.=.0118, pstress interaction was observed for BMI (β=0.007, S.E.=.0027, p=.015). Findings from this study demonstrate that the stress experience interacts with emotional eating to influence BMI. Based on these findings, culturally relevant interventions that target the unique stress experience and eating behavior patterns of young African American women are warranted. Copyright © 2015. Published by Elsevier Ltd.

  1. Black layers on historical architecture.

    Science.gov (United States)

    Toniolo, Lucia; Zerbi, Carlotta M; Bugini, Roberto

    2009-03-01

    The external surface of any building in urban polluted environment is unavoidably destined to be covered with layers that assume a grey to black colour and are generally called 'black crusts'. These, according to standard protocols and glossary, are deteriorated surface layers of stone material; they can have variable thickness, are hard and fragile and can detach spontaneously from the substrate, which, in general, is quite decayed. Plain visual examination may lead to consider 'black crusts' all similar, whilst only a careful diagnostic investigation can distinguish 'black crusts' and the consequences of their formation on stone substrates. In this paper, various black layers on marble are studied and compared and the morphological and compositional characteristics discussed according to the related mechanisms of formation. Differences between old (hundred years) and recent crusts (30 years) are investigated and pointed out. Samples of black crusts collected from the Milan Cathedral façade (Candoglia Marble) have been studied and compared with the careful and synergic employ of traditional techniques: optical (transmission and reflected VIS light) and electron microscopy, X-ray spectrometry and micro-Fourier transform infrared spectroscopy. Visual examination of loose fragments does not allow to point out outstanding differences amongst the various samples; black layers have similar main mineral components, gypsum and airborne particles, with different spatial distribution. The microscopic studies allowed to point out the porosity differences, the gypsum crystallisation habit, different amount of embedded particles, level and progress of marble decay. The observations lead to define three main types of black crusts: black crust deriving from marble sulphation, compact deposit and encrustation due to exogenic materials deposition. Black crusts show evidence of sulphation in progress, without a clear continuity solution between crust and marble; the lack of

  2. Race in Buenos Aires. Blackness, Whiteness, African Descent and Mestizaje in the White Capital City

    Directory of Open Access Journals (Sweden)

    Lea Geler

    2016-03-01

    Full Text Available This article analyzes how racial categories are produced and reproduced in Buenos Aires, Argentina’s capital city. To that end, this article focuses on the cases of three Afro-Descendant porteña women who, by local standards, are fully white.  Their stories allow us to explore, in the first place, how categories like “black,” “white,” and others are used and understood in contemporary Buenos Aires and how this use configures two types of blackness (racial blackness and popular blackness and makes it impossible for mestizaje categories to emerge. In the second place, through these cases this article explores how people’s very “ways of being” are at play, creating a discriminatory and oppressive environment for people at risk of not matching the ideal of the nation.

  3. Nonsingular black hole

    Energy Technology Data Exchange (ETDEWEB)

    Chamseddine, Ali H. [American University of Beirut, Physics Department, Beirut (Lebanon); I.H.E.S., Bures-sur-Yvette (France); Mukhanov, Viatcheslav [Niels Bohr Institute, Niels Bohr International Academy, Copenhagen (Denmark); Ludwig-Maximilians University, Theoretical Physics, Munich (Germany); MPI for Physics, Munich (Germany)

    2017-03-15

    We consider the Schwarzschild black hole and show how, in a theory with limiting curvature, the physical singularity ''inside it'' is removed. The resulting spacetime is geodesically complete. The internal structure of this nonsingular black hole is analogous to Russian nesting dolls. Namely, after falling into the black hole of radius r{sub g}, an observer, instead of being destroyed at the singularity, gets for a short time into the region with limiting curvature. After that he re-emerges in the near horizon region of a spacetime described by the Schwarzschild metric of a gravitational radius proportional to r{sub g}{sup 1/3}. In the next cycle, after passing the limiting curvature, the observer finds himself within a black hole of even smaller radius proportional to r{sub g}{sup 1/9}, and so on. Finally after a few cycles he will end up in the spacetime where he remains forever at limiting curvature. (orig.)

  4. Black Teenage Pregnancy

    Directory of Open Access Journals (Sweden)

    Loretta I. Winters

    2012-01-01

    Full Text Available This article examines the relative importance of race and socioeconomic status (SES in determining whether Black and White teenagers report having ever been pregnant. Data gathered from 1999 to 2006 by the National Center for Health Statistics of the Center for Disease Control and Prevention included 1,580 Black and White females aged 15 to 19 years. Results supported the effects of race and SES, with SES having the stronger effect. However, the effects of race and SES differ when controlling for the state of the economy. No difference between Blacks and Whites was found during better economic times. During 2003-2004, the period of greatest economic stress, race was determined to be the only predictor of teenage pregnancy. In particular, during 2005-2006, the reduction in pregnancy rates for Black minors (15-17 fell below those for White minors within their respective SES categories. Policy implications are discussed in light of these findings.

  5. Black Girl Cartography: Black Girlhood and Place-Making in Education Research

    Science.gov (United States)

    Butler, Tamara T.

    2018-01-01

    Drawing on research in education, Black Girlhood studies, and conversations connected to girlhood and cartography, this chapter calls for transdisciplinary analyses of Black girls' sociocultural and geopolitical locations in education research. In reviewing education research documenting the practices and interrogating the experiences of Black…

  6. The Intersection of Race and Gender in School Leadership for Three Black Female Principals

    Science.gov (United States)

    Reed, Latish Cherie

    2012-01-01

    Using four assumptions of Black feminism, this qualitative study describes the practice of three African-American female principals in predominantly African-American, urban high schools. First, in general, the principals seemed to understand their experiences as part of a larger historical context. Second, given the shared racial and gender…

  7. Axion-dilation black holes

    International Nuclear Information System (INIS)

    Kallosh, R.

    1993-01-01

    In this talk some essential features of stringy black holes are described. The author considers charged U(1) and U(1) x U(1) four-dimensional axion-dilaton black holes. The Hawking temperature and the entropy of all solutions are shown to be simple functions of the squares of supercharges, defining the positivity bounds. Spherically symmetric and multi black hole solutions are presented. The extreme solutions with zero entropy (holons) represent a ground state of the theory and are characterized by elementary dilaton, axion, electric, and magnetic charges. The attractive gravitational and axion-dilaton force is balanced by the repulsive electromagnetic force. The author discusses the possibility of splitting of nearly extreme black holes. 11 refs

  8. What Can We Learn About Black-Hole Formation from Black-Hole X-ray Binaries?

    NARCIS (Netherlands)

    Nelemans, G.A.

    2007-01-01

    I discuss the effect of the formation of a black hole on a (close) binary and show some of the current constraints that the observed properties of black hole X-ray binaries put on the formation of black holes. In particular, I discuss the evidence for and against asymmetric kicks imparted on the

  9. Why Are Black Employers More Likely Than White Employers To Hire Blacks? Discussion Paper.

    Science.gov (United States)

    Stoll, Michael A.; Raphael, Steven; Holzer, Harry J.

    This study investigated why black employers tend to hire blacks at higher rates than do white employers and examined individual steps in the hiring process, the role of the hiring agent's race, and the degree to which variation in black application rates related to differences in observable characteristics, such as an establishment's physical…

  10. Black holes and the multiverse

    International Nuclear Information System (INIS)

    Garriga, Jaume; Vilenkin, Alexander; Zhang, Jun

    2016-01-01

    Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleating during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse

  11. Black holes and the multiverse

    Energy Technology Data Exchange (ETDEWEB)

    Garriga, Jaume [Departament de Fisica Fonamental i Institut de Ciencies del Cosmos, Universitat de Barcelona, Marti i Franques, 1, Barcelona, 08028 Spain (Spain); Vilenkin, Alexander; Zhang, Jun, E-mail: jaume.garriga@ub.edu, E-mail: vilenkin@cosmos.phy.tufts.edu, E-mail: jun.zhang@tufts.edu [Institute of Cosmology, Tufts University, 574 Boston Ave, Medford, MA, 02155 (United States)

    2016-02-01

    Vacuum bubbles may nucleate and expand during the inflationary epoch in the early universe. After inflation ends, the bubbles quickly dissipate their kinetic energy; they come to rest with respect to the Hubble flow and eventually form black holes. The fate of the bubble itself depends on the resulting black hole mass. If the mass is smaller than a certain critical value, the bubble collapses to a singularity. Otherwise, the bubble interior inflates, forming a baby universe, which is connected to the exterior FRW region by a wormhole. A similar black hole formation mechanism operates for spherical domain walls nucleating during inflation. As an illustrative example, we studied the black hole mass spectrum in the domain wall scenario, assuming that domain walls interact with matter only gravitationally. Our results indicate that, depending on the model parameters, black holes produced in this scenario can have significant astrophysical effects and can even serve as dark matter or as seeds for supermassive black holes. The mechanism of black hole formation described in this paper is very generic and has important implications for the global structure of the universe. Baby universes inside super-critical black holes inflate eternally and nucleate bubbles of all vacua allowed by the underlying particle physics. The resulting multiverse has a very non-trivial spacetime structure, with a multitude of eternally inflating regions connected by wormholes. If a black hole population with the predicted mass spectrum is discovered, it could be regarded as evidence for inflation and for the existence of a multiverse.

  12. Race Attribution Modifies the Association Between Daily Discrimination and Major Depressive Disorder Among Blacks: the Role of Gender and Ethnicity.

    Science.gov (United States)

    Assari, Shervin; Watkins, Daphne C; Caldwell, Cleopatra H

    2015-06-01

    Although the association between discrimination and depression among Blacks is well-known, we do not know if this effect is influenced by race attribution. In this current study, we investigated the effect modification of race attribution on the association between everyday discrimination and major depressive disorder (MDD) among Blacks in the United States, and whether this effect modification is influenced by the intersection of ethnicity and gender. With a cross-sectional design, this study used data from the National Survey of American Life (NSAL), 2001-2003. The study included a nationally representative sample of Blacks (n = 5,008), composed of 3,570 African Americans and 1,438 Caribbean Blacks. Everyday discrimination, two single-item measures of race attribution (race as the major barrier against upward social mobility, and race as the main cause for being discriminated against) and 12-month MDD were measured. In the first step, we fit logistic regressions to the pooled sample. In the next step, we ran regressions specific to the intersections of ethnicity and gender. Interaction between race attribution and discrimination were also entered into the models. Among Caribbean Black men, the belief that race is a major barrier against one's own upward social mobility modified the association between exposure to daily discrimination and MDD. In this group, the association between discrimination and MDD was weaker among those who believed that race is a major barrier against one's own upward social mobility. Race attribution did not modify the association between discrimination and MDD among African American men, African American women, and Caribbean Black women. The other measure of race attribution (race as the main cause of being discriminated against) did not modify the association between discrimination and MDD in any ethnicity by gender subgroups. Among Caribbean Black men, the link between everyday discrimination and depression may depend on seeing

  13. Super-horizon primordial black holes

    International Nuclear Information System (INIS)

    Harada, Tomohiro; Carr, B.J.

    2005-01-01

    We discuss a new class of solutions to the Einstein equations which describe a primordial black hole (PBH) in a flat Friedmann background. Such solutions arise if a Schwarzschild black hole is patched onto a Friedmann background via a transition region. They are possible providing the black hole event horizon is larger than the cosmological apparent horizon. Such solutions have a number of strange features. In particular, one has to define the black hole and cosmological horizons carefully and one then finds that the mass contained within the black hole event horizon decreases when the black hole is larger than the Friedmann cosmological apparent horizon, although its area always increases. These solutions involve two distinct future null infinities and are interpreted as the conversion of a white hole into a black hole. Although such solutions may not form from gravitational collapse in the same way as standard PBHs, there is nothing unphysical about them, since all energy and causality conditions are satisfied. Their conformal diagram is a natural amalgamation of the Kruskal diagram for the extended Schwarzschild solution and the conformal diagram for a black hole in a flat Friedmann background. In this paper, such solutions are obtained numerically for a spherically symmetric universe containing a massless scalar field, but it is likely that they exist for more general matter fields and less symmetric systems

  14. America's black intellectuals: the cultural perspective as the basis of construction of a subjectivity of a liberating's character (1920-1940

    Directory of Open Access Journals (Sweden)

    Pedro Alexander Cubas-Hernández

    2012-12-01

    Full Text Available In this essay, four intellectual experiences based on culture, which had the objective of generating self-esteem in the black population of America, will be analyzed. Marcus Garvey's pan-African ideal, the poetry of the Black movement Harlem Renaissance, the renovating verses of Nicolás Guillén and the incisive journalism of Gustavo Urrutia helped to construct a black subjectivity of liberating nature.---Original in Spanish.

  15. THE BITTER TRUTH: A COMPARATIVE ANALYSIS OF BLACK MALE AND BLACK FEMALE ENTREPRENEURS

    OpenAIRE

    SHERRHONDA R. GIBBS

    2014-01-01

    The paper examines variables stated to be central to entrepreneurial success and reports differences between black male and black female entrepreneurs. Variables studied include task-specific efficacy, firm performance and opportunity recognition. Using a sample of 85 males and 58 females, results indicated that although black male and female entrepreneurs are somewhat similar in terms of business environment and demographics (e.g., education levels, years of business industry experience, lik...

  16. The emergence of the Black Methodist Consultation and its possible prophetic voice in post-apartheid South Africa

    Directory of Open Access Journals (Sweden)

    Ndikho Mtshiselwa

    2015-06-01

    Full Text Available Racism is an issue which the activism of the Black Methodist Consultation (BMC was set to address during the South African apartheid rule, a view which black theologians and church historians generally accept. This observation brought to mind, in turn, the influence that the Black Consciousness philosophy and the black theology of liberation had on the establishment of the BMC. Recounting such an influence, this article provides a reflection on the formation of the BMC in 1975. In such a reflection, the hypothesis is that the prophetic voice of the BMC is crucial in post-apartheid South Africa. Firstly, the interconnectedness of the Black Consciousness philosophy, the black theology of liberation and the BMC is highlighted. Secondly, the article proceeds to navigate the possible prophetic voice of the BMC in post- apartheid South Africa. In the end, this article sees the BMC as a crucial interlocutor of liberation in present South Africa.

  17. When Supermassive Black Holes Wander

    Science.gov (United States)

    Kohler, Susanna

    2018-05-01

    Are supermassive black holes found only at the centers of galaxies? Definitely not, according to a new study in fact, galaxies like the Milky Way may harbor several such monsters wandering through their midst.Collecting Black Holes Through MergersIts generally believed that galaxies are built up hierarchically, growing in size through repeated mergers over time. Each galaxy in a major merger likely hosts a supermassive black hole a black hole of millions to billions of times the mass of the Sun at its center. When a pair of galaxies merges, their supermassive black holes will often sink to the center of the merger via a process known as dynamical friction. There the supermassive black holes themselves will eventually merge in a burst of gravitational waves.Spatial distribution and velocities of wandering supermassive black holes in three of the authors simulated galaxies, shown in edge-on (left) and face-on (right) views of the galaxy disks. Click for a closer look. [Tremmel et al. 2018]But if a galaxy the size of the Milky Way was built through a history of many major galactic mergers, are we sure that all its accumulated supermassive black holes eventually merged at the galactic center? A new study suggests that some of these giants might have escaped such a fate and they now wander unseen on wide orbits through their galaxies.Black Holes in an Evolving UniverseLed by Michael Tremmel (Yale Center for Astronomy Astrophysics), a team of scientists has used data from a large-scale cosmological simulation, Romulus25, to explore the possibility of wandering supermassive black holes. The Romulus simulations are uniquely suited to track the formation and subsequent orbital motion of supermassive black holes as galactic halos are built up through mergers over the history of the universe.From these simulations, Tremmel and collaborators find an end total of 316 supermassive black holes residing within the bounds of 26 Milky-Way-mass halos. Of these, roughly a third are

  18. Black powder in gas pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Sherik, Abdelmounam [Saudi Aramco, Dhahran (Saudi Arabia)

    2009-07-01

    Despite its common occurrence in the gas industry, black powder is a problem that is not well understood across the industry, in terms of its chemical and physical properties, source, formation, prevention or management of its impacts. In order to prevent or effectively manage the impacts of black powder, it is essential to have knowledge of its chemical and physical properties, formation mechanisms and sources. The present paper is divided into three parts. The first part of this paper is a synopsis of published literature. The second part reviews the recent laboratory and field work conducted at Saudi Aramco Research and Development Center to determine the compositions, properties, sources and formation mechanisms of black powder in gas transmission systems. Microhardness, nano-indentation, X-ray Diffraction (XRD), X-ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) techniques were used to analyze a large number of black powder samples collected from the field. Our findings showed that black powder is generated inside pipelines due to internal corrosion and that the composition of black powder is dependent on the composition of transported gas. The final part presents a summary and brief discussion of various black powder management methods. (author)

  19. Anyon black holes

    Science.gov (United States)

    Aghaei Abchouyeh, Maryam; Mirza, Behrouz; Karimi Takrami, Moein; Younesizadeh, Younes

    2018-05-01

    We propose a correspondence between an Anyon Van der Waals fluid and a (2 + 1) dimensional AdS black hole. Anyons are particles with intermediate statistics that interpolates between a Fermi-Dirac statistics and a Bose-Einstein one. A parameter α (0 quasi Fermi-Dirac statistics for α >αc, but a quasi Bose-Einstein statistics for α quasi Bose-Einstein statistics. For α >αc and a range of values of the cosmological constant, there is, however, no event horizon so there is no black hole solution. Thus, for these values of cosmological constants, the AdS Anyon Van der Waals black holes have only quasi Bose-Einstein statistics.

  20. Variant Branching of the Common Femoral Artery in a Black Kenyan ...

    African Journals Online (AJOL)

    Branching pattern of common femoral artery is important during artery catheterization, orthopaedic, plastic and general surgery in the proximal thigh. Frequency of variant branching shows ethnic variation but there are no data for black African populations. Since atherosclerotic diseases are increasing and femoral artery ...

  1. Decolonizing "Othello" in Search of Black Feminist North American Identities: Djanet Sears' "Harlem Duet" and Toni Morrison's "Desdemona"

    Science.gov (United States)

    Cucarella-Ramon, Vicent

    2017-01-01

    The plays "Harlem Duet" (1997) by African Canadian playwright Djanet Sears and "Desdemona" (2012) by Toni Morrison signify upon European texts aiming to carve out a new definition of what it means to be black in North America. Therefore, both texts make for interesting reading in the study of (black) identity construction…

  2. Black-hole driven winds

    International Nuclear Information System (INIS)

    Punsly, B.M.

    1988-01-01

    This dissertation is a study of the physical mechanism that allows a large scale magnetic field to torque a rapidly rotating, supermassive black hole. This is an interesting problem as it has been conjectured that rapidly rotating black holes are the central engines that power the observed extragalactic double radio sources. Axisymmetric solutions of the curved space-time version of Maxwell's equations in the vacuum do not torque black holes. Plasma must be introduced for the hole to mechanically couple to the field. The dynamical aspect of rotating black holes that couples the magnetic field to the hole is the following. A rotating black hole forces the external geometry of space-time to rotate (the dragging of inertial frames). Inside of the stationary limit surface, the ergosphere, all physical particle trajectories must appear to rotate in the same direction as the black hole as viewed by the stationary observers at asymptotic infinity. In the text, it is demonstrated how plasma that is created on field lines that thread both the ergosphere and the equatorial plane will be pulled by gravity toward the equator. By the aforementioned properties of the ergosphere, the disk must rotate. Consequently, the disk acts like a unipolar generator. It drives a global current system that supports the toroidal magnetic field in an outgoing, magnetically dominated wind. This wind carries energy (mainly in the form of Poynting flux) and angular momentum towards infinity. The spin down of the black hole is the ultimate source of this energy and angular momentum flux

  3. ULTRAMASSIVE BLACK HOLE COALESCENCE

    International Nuclear Information System (INIS)

    Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter

    2015-01-01

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC 1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC 1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gravitational wave emission dominates, and the black holes coalesce in a mere few Myr. Curiously, these extremely massive binaries appear to nearly bypass the three-body scattering evolutionary phase. Our study suggests that in this extreme case, SMBH coalescence is governed by dynamical friction followed nearly directly by gravitational wave emission, resulting in a rapid and efficient SMBH coalescence timescale. We discuss the implications for gravitational wave event rates and hypervelocity star production

  4. "Iron-Clad" Evidence For Spinning Black Hole

    Science.gov (United States)

    2003-09-01

    Telltale X-rays from iron may reveal if black holes are spinning or not, according to astronomers using NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory. The gas flows and bizarre gravitational effects observed near stellar black holes are similar to those seen around supermassive black holes. Stellar black holes, in effect, are convenient `scale models' of their much larger cousins. Black holes come in at least two different sizes. Stellar black holes are between five and 20 times the mass of the Sun. At the other end of the size scale, supermassive black holes contain millions or billions times the mass of our Sun. The Milky Way contains both a supermassive black hole at its center, as well as a number of stellar black holes sprinkled throughout the Galaxy. At a press conference at the "Four Years of Chandra" symposium in Huntsville, Ala., Jon Miller of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. discussed recent results on the X-ray spectra, or distribution of X-rays with energy, from the iron atoms in gas around three stellar black holes in the Milky Way. "Discovering the high degree of correspondence between stellar and supermassive black holes is a real breakthrough," said Miller. "Because stellar black holes are smaller, everything happens about a million times faster, so they can be used as a test-bed for theories of how spinning black holes affect the space and matter around them." X-rays from a stellar black hole are produced when gas from a nearby companion star is heated to tens of millions of degrees as it swirls toward the black hole. Iron atoms in this gas produce distinctive X-ray signals that can be used to study the orbits of particles around the black hole. For example, the gravity of a black hole can shift the X-rays to lower energies. "The latest work provides the most precise measurements yet of the X-ray spectra for stellar black holes," said Miller. "These data help rule out

  5. Protecting Black Girls

    Science.gov (United States)

    Morris, Monique W.

    2016-01-01

    Statistics show that black girls in U.S. K-12 public schools are overrepresented among students who face disciplinary approaches (such as suspensions) that exclude or even criminalize them. Morris explains how black girls face conditions that make them vulnerable to a phenomenon she calls "school to confinement pathways"--conditions like…

  6. Black holes a very short introduction

    CERN Document Server

    Blundell, Katherine

    2015-01-01

    Black holes are a constant source of fascination to many due to their mysterious nature. Black Holes: A Very Short Introduction addresses a variety of questions, including what a black hole actually is, how they are characterized and discovered, and what would happen if you came too close to one. It explains how black holes form and grow—by stealing material that belongs to stars—as well as how many there may be in the Universe. It also explores the large black holes found in the centres of galaxies, and how black holes power quasars and lie behind other spectacular phenomena in the cosmos.

  7. Dye-sensitized solar cells fabricated with black raspberry, black carrot and rosella juice

    Science.gov (United States)

    Tekerek, S.; Kudret, A.; Alver, Ü.

    2011-10-01

    In this work, dye sensitized solar cells (DSSC's) were constructed from black raspberry ( Rubus Ideaus), black carrot ( Daucuscarota L.) and rosella juice ( Hibiscus Sabdariffa L.). In order to fabricate a DSSC the fluorine-doped tin (IV) oxide (FTO) thin films obtained by using spray pyrolysis technique were used as a substrate. TiO2 films on FTO layers were prepared by doctor-blading technique. Platinum-coated counter electrode and liquid Iodide/Iodine electrolyte solution were used to fabricate DSSC's. The efficiencies of solar cells produced with black carrot, rosella and black raspberry juice were calculated as 0.25%, 0.16% and 0.16% respectively, under a sunny day in Kahramanmaraş-Turkey.

  8. Graft-copolymerization onto carbon black

    International Nuclear Information System (INIS)

    Nakase, Yoshiaki; Nishii, Masanobu; Kijima, Toshiyuki; Kato, Hiroshi.

    1988-07-01

    Radiation-induced graft copolymerization of vinyl monomer onto carbon black was performed. During the γ-ray- and electron beam-induced polymerization (In-source), or the electron beam post-polymerization, the graft-copolymerization behavior was affected by the kinds of both carbon blacks and monomers, i.e. the smaller the size of carbon black particles, the higher the apparent grafted fraction. Homopolymer in the grafted carbon black samples was washed out by the solvent of the polymer, and the extracted polymer seemed to be dimer or trimer of the used monomer. In the case of the post-polymerization with the pre-irradiation doses of 50 Mrad, homopolymer was hardly observed. The polymer sheets of plastics or rubbers with grafted carbon black had an electrical conductivity unalterable considerably by the heating cycles. The particles of grafted carbon black in the sheet might be kept much more at the surface layer within 100 nm depth than at the inner layer. (author)

  9. Particle creation by black holes

    International Nuclear Information System (INIS)

    Hawking, S.W.

    1975-01-01

    In the classical theory black holes can only absorb and not emit particles. However it is shown that quantum mechanical effects cause black holes to create and emit particles. This thermal emission leads to a slow decrease in the mass of the black hole and to its eventual disappearance: any primordial black hole of mass less than about 10 15 g would have evaporated by now. Although these quantum effects violate the classical law that the area of the event horizon of a black hole cannot decrease, there remains a Generalized Second Law: S + 1/4 A never decreases where S is the entropy of matter outside black holes and A is the sum of the surface areas of the event horizons. This shows that gravitational collapse converts the baryons and leptons in the collapsing body into entropy. It is tempting to speculate that this might be the reason why the Universe contains so much entropy per baryon. (orig.) [de

  10. Black Hole's 1/N Hair

    CERN Document Server

    Dvali, Gia

    2013-01-01

    According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

  11. Shaping Globular Clusters with Black Holes

    Science.gov (United States)

    Kohler, Susanna

    2018-03-01

    How many black holes lurk within the dense environments of globular clusters, and how do these powerful objects shape the properties of the cluster around them? One such cluster, NGC 3201, is now helping us to answer these questions.Hunting Stellar-Mass Black HolesSince the detection of merging black-hole binaries by the Laser Interferometer Gravitational-Wave Observatory (LIGO), the dense environments of globular clusters have received increasing attention as potential birthplaces of these compact binary systems.The central region of the globular star cluster NGC 3201, as viewed by Hubble. The black hole is in orbit with the star marked by the blue circle. [NASA/ESA]In addition, more and more stellar-mass black-hole candidates have been observed within globular clusters, lurking in binary pairs with luminous, non-compact companions. The most recent of these detections, found in the globular cluster NGC 3201, stands alone as the first stellar-mass black hole candidate discovered via radial velocity observations: the black holes main-sequence companion gave away its presence via a telltale wobble.Now a team of scientists led by Kyle Kremer (CIERA and Northwestern University) is using models of this system to better understand the impact that black holes might have on their host clusters.A Model ClusterThe relationship between black holes and their host clusters is complicated. Though the cluster environment can determine the dynamical evolution of the black holes, the retention rate of black holes in a globular cluster (i.e., how many remain in the cluster when they are born as supernovae, rather than being kicked out during the explosion) influences how the host cluster evolves.Kremer and collaborators track this complex relationship by modeling the evolution of a cluster similar to NGC 3201 with a Monte Carlo code. The code incorporates physics relevant to the evolution of black holes and black-hole binaries in globular clusters, such as two-body relaxation

  12. Stability of squashed Kaluza-Klein black holes

    International Nuclear Information System (INIS)

    Kimura, Masashi; Ishihara, Hideki; Murata, Keiju; Soda, Jiro

    2008-01-01

    The stability of squashed Kaluza-Klein black holes is studied. The squashed Kaluza-Klein black hole looks like a five-dimensional black hole in the vicinity of horizon and looks like a four-dimensional Minkowski spacetime with a circle at infinity. In this sense, squashed Kaluza-Klein black holes can be regarded as black holes in the Kaluza-Klein spacetimes. Using the symmetry of squashed Kaluza-Klein black holes, SU(2)xU(1)≅U(2), we obtain master equations for a part of the metric perturbations relevant to the stability. The analysis based on the master equations gives strong evidence for the stability of squashed Kaluza-Klein black holes. Hence, the squashed Kaluza-Klein black holes deserve to be taken seriously as realistic black holes in the Kaluza-Klein spacetime.

  13. Gender, Mentoring Experiences, and Salary Attainment among Graduates of an Historically Black University.

    Science.gov (United States)

    Dreher, George F.; Chargois, Josephine A.

    1998-01-01

    Survey responses from 170 of 685 African-American graduates of historically Black colleges revealed no gender-based pay differences. Those who had White male mentors had some pay advantages over those without mentors. (SK)

  14. Queering Black Racial Identity Development

    Science.gov (United States)

    Johnson, Alandis A.; Quaye, Stephen John

    2017-01-01

    We used queer theory to encourage readers to think differently about previous theories about Black racial identity development. Queer theory facilitates new and deeper understandings of how Black people develop their racial identities, prompting more fluidity and nuance. Specifically, we present a queered model of Black racial identity development…

  15. A Typology of Black Leadership.

    Science.gov (United States)

    Tryman, Donald L.

    1977-01-01

    A leadership typology is developed which describes the relationship of Black leadership styles to the Black masses. The role that such leadership plays in the political integration of Blacks as an ethnic group is analyzed. Four authority types are discussed: traditional brokerage, cultural nationalist, religious nationalist, and faddist…

  16. Black p-branes versus black holes in non-asymptotically flat Einstein-Yang-Mills theory

    Science.gov (United States)

    Habib Mazharimousavi, S.; Halilsoy, M.

    2016-09-01

    We present a class of non-asymptotically flat (NAF) charged black p-branes (BpB) with p-compact dimensions in higher-dimensional Einstein-Yang-Mills theory. Asymptotically the NAF structure manifests itself as an anti-de sitter spacetime. We determine the total mass/energy enclosed in a thin shell located outside the event horizon. By comparing the entropies of BpB with those of black holes in the same dimensions we derive transition criteria between the two types of black objects. Given certain conditions satisfied, our analysis shows that BpB can be considered excited states of black holes. An event horizon r+ versus charge square Q2 plot for the BpB reveals such a transition where r+ is related to the horizon radius rh of the black hole (BH) both with the common charge Q.

  17. The search for black holes

    International Nuclear Information System (INIS)

    Torn, K.

    1976-01-01

    Conceivable experimental investigations to prove the existence of black holes are discussed. Double system with a black hole turning around a star-satellite are in the spotlight. X-radiation emmited by such systems and resulting from accretion of the stellar gas by a black hole, and the gas heating when falling on the black hole might prove the model suggested. A source of strong X-radiation observed in the Cygnus star cluster and referred to as Cygnus X-1 may be thus identified as a black hole. Direct registration of short X-ray pulses with msec intervals might prove the suggestion. The lack of appropriate astrophysic facilities is pointed out to be the major difficulty on the way of experimental verifications

  18. Nonextremal stringy black hole

    International Nuclear Information System (INIS)

    Suzuki, K.

    1997-01-01

    We construct a four-dimensional BPS saturated heterotic string solution from the Taub-NUT solution. It is a nonextremal black hole solution since its Euler number is nonzero. We evaluate its black hole entropy semiclassically. We discuss the relation between the black hole entropy and the degeneracy of string states. The entropy of our string solution can be understood as the microscopic entropy which counts the elementary string states without any complications. copyright 1997 The American Physical Society

  19. African American Diaspora

    Directory of Open Access Journals (Sweden)

    Angela Brown

    2013-05-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. With regard to all historic migrations (forced and voluntary, the African Union defined the African diaspora as "[consisting] of people of African origin living outside the continent, irrespective of their citizenship and nationality and who are willing to contribute to the development of the continent and the building of the African Union." Its constitutive act declares that it shall "invite and encourage the full participation of the African diaspora as an important part of our continent, in the building of the African Union."

  20. How Black women make sense of 'White' and 'Black' fashion magazines: a qualitative think aloud study.

    Science.gov (United States)

    Ogden, Jane; Russell, Sheriden

    2013-12-01

    This qualitative think aloud study explored how Black women (n = 32) processed information from a White or Black fashion magazine. Comments to the 'White' magazine were characterised by rejection, being critical of the media and ambivalence, whereas they responded to the 'Black' magazine with celebration, identification and a search for depth. Transcending these themes was their self-identity of being a Black woman that was brought to the fore either by a sense of exclusion (White magazine) or engagement (Black magazine). Such an identity provides resilience against the media's thin ideals by minimising the processes of social comparison and internalisation.

  1. Charged black rings at large D

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin [Department of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter,5 Yiheyuan Rd, Beijing 100871 (China); Center for High Energy Physics, Peking University,5 Yiheyuan Rd, Beijing 100871 (China); Li, Peng-Cheng; Wang, Zi-zhi [Department of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,5 Yiheyuan Rd, Beijing 100871 (China)

    2017-04-28

    We study the charged slowly rotating black holes in the Einstein-Maxwell theory in the large dimensions (D). By using the 1/D expansion in the near regions of the black holes we obtain the effective equations for the charged slowly rotating black holes. The effective equations capture the dynamics of various stationary solutions, including the charged black ring, the charged slowly rotating Myers-Perry black hole and the charged slowly boosted black string. Via different embeddings we construct these stationary solutions explicitly. For the charged black ring at large D, we find that the charge lowers the angular momentum due to the regularity condition on the solution. By performing the perturbation analysis of the effective equations, we obtain the quasinormal modes of the charge perturbation and the gravitational perturbation analytically. Like the neutral case the charged thin black ring suffers from the Gregory-Laflamme-like instability under the non-axisymmetric perturbations, but the charge weakens the instability. Besides, we find that the large D analysis always respects the cosmic censorship.

  2. VIOLENT BLACK MAN AND THE MYTH OF BLACK MACHO IN EUGENE O’NEILL’S "THE DREAMY KID"

    Directory of Open Access Journals (Sweden)

    Agnieszka Łobodziec

    2014-10-01

    Full Text Available The aim of this article is the investigation of the extent to which Eugene O’Neill, in his drama "The Dreamy Kid", (reconstructs, or employs, the black macho myth, which negatively images black men as marginalized and violent. This undertaking questions O’Neill’s self-proclaimed progressive racial attitudes and stated focus on the universal nature of human existence, which he professed to express through drama. Moreover, the article challenges the mainstream view of "The Dreamy Kid" as progressive. Although the play focalizes the experience of a marginalized black man, which could be interpreted as the playwright’s concern with the unjust racial and class stratification of American society, O’Neill’s production, unfortunately, contains a number of pervasive stereotypes relative to black people’s alleged moral degeneracy, primitiveness, and violent behavior, which threatens the white dominated constructed order. In terms of gendered racial politics, in the article attention is given to O’Neill’s presentation of black male negotiations with the white patriarchal power structure, embodied by the police forces, and with black matriarchy, represented by O’Neill’s stereotypical character portrayal of a dominant elderly black woman. Lastly, an overall analysis is performed in light of the call for an autonomous black art, which emerged among black artists in opposition to the demeaning, unrealistic, stereotypical portrayals of black victims of oppression by white American writers.

  3. Charged black holes with scalar hair

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Zhong-Ying; Lü, H. [Center for Advanced Quantum Studies, Department of Physics,Beijing Normal University, Beijing 100875 (China)

    2015-09-10

    We consider a class of Einstein-Maxwell-Dilaton theories, in which the dilaton coupling to the Maxwell field is not the usual single exponential function, but one with a stationary point. The theories admit two charged black holes: one is the Reissner-Nordstrøm (RN) black hole and the other has a varying dilaton. For a given charge, the new black hole in the extremal limit has the same AdS{sub 2}×Sphere near-horizon geometry as the RN black hole, but it carries larger mass. We then introduce some scalar potentials and obtain exact charged AdS black holes. We also generalize the results to black p-branes with scalar hair.

  4. Information Retention by Stringy Black Holes

    CERN Document Server

    Ellis, John

    2015-01-01

    Building upon our previous work on two-dimensional stringy black holes and its extension to spherically-symmetric four-dimensional stringy black holes, we show how the latter retain information. A key r\\^ole is played by an infinite-dimensional $W_\\infty$ symmetry that preserves the area of an isolated black-hole horizon and hence its entropy. The exactly-marginal conformal world-sheet operator representing a massless stringy particle interacting with the black hole necessarily includes a contribution from $W_\\infty$ generators in its vertex function. This admixture manifests the transfer of information between the string black hole and external particles. We discuss different manifestations of $W_\\infty$ symmetry in black-hole physics and the connections between them.

  5. Is there life inside black holes?

    International Nuclear Information System (INIS)

    Dokuchaev, V I

    2011-01-01

    Bound inside rotating or charged black holes, there are stable periodic planetary orbits, which neither come out nor terminate at the central singularity. Stable periodic orbits inside black holes exist even for photons. These bound orbits may be defined as orbits of the third kind, following the Chandrasekhar classification of particle orbits in the black hole gravitational field. The existence domain for the third-kind orbits is rather spacious, and thus there is place for life inside supermassive black holes in the galactic nuclei. Interiors of the supermassive black holes may be inhabited by civilizations, being invisible from the outside. In principle, one can get information from the interiors of black holes by observing their white hole counterparts. (paper)

  6. The Criminalization of Black Angeleno Women: Institutionalized Racism and Sexism in Los Angeles, 1928-1938

    OpenAIRE

    Boyd, Kaitlin Therese

    2012-01-01

    "The Criminalization of Black Angeleno Women" illuminates what happened in early 20th century Los Angeles when African American women, particularly working poor females, came into contact with the Los Angeles Police Department, the court system and the local, mainstream media. Individually, but especially collaboratively, these institutions lead to the overrepresentation of Black, statistically and in the public mind, in the local sex trade. Essentially, this thesis traces the biases of the...

  7. Black holes turn white fast, otherwise stay black: no half measures

    International Nuclear Information System (INIS)

    Barceló, Carlos; Carballo-Rubio, Raúl; Garay, Luis J.

    2016-01-01

    Recently, various authors have proposed that the dominant ultraviolet effect in the gravitational collapse of massive stars to black holes is the transition between a black-hole geometry and a white-hole geometry, though their proposals are radically different in terms of their physical interpretation and characteristic time scales http://dx.doi.org/10.1142/S021827181442022X, http://dx.doi.org/10.1103/PhysRevD.92.104020. Several decades ago, it was shown by Eardley that white holes are highly unstable to the accretion of small amounts of matter, being rapidly turned into black holes http://dx.doi.org/10.1103/PhysRevLett.33.442. Studying the crossing of null shells on geometries describing the black-hole to white-hole transition, we obtain the conditions for the instability to develop in terms of the parameters of these geometries. We conclude that transitions with long characteristic time scales are pathologically unstable: occasional perturbations away from the perfect vacuum around these compact objects, even if being imperceptibly small, suffocate the white-hole explosion. On the other hand, geometries with short characteristic time scales are shown to be robust against perturbations, so that the corresponding processes could take place in real astrophysical scenarios. This motivates a conjecture about the transition amplitudes of different decay channels for black holes in a suitable ultraviolet completion of general relativity.

  8. Black holes and quantum processes in them

    International Nuclear Information System (INIS)

    Frolov, V.P.

    1976-01-01

    The latest achievements in the physics of black holes are reviewed. The problem of quantum production in a strong gravitational field of black holes is considered. Another parallel discovered during investigation of interactions between black holes and between black holes and surrounding media, is also drawn with thermodynamics. A gravitational field of rotating black holes is considered. Some cosmological aspects of evaporation of small black holes are discussed as well as possibilities to observe them

  9. The Black Journalist in South Africa.

    Science.gov (United States)

    Hachten, William A.

    The role of the black journalist in South Africa is contradictory, precarious, and permeated with politics. There is little freedom of expression for blacks in South Africa, yet white-owned newspapers have expanded their coverage of black news, and some have special editions for black readers. As a result, the English language press is using more…

  10. Statistical clustering of primordial black holes

    Energy Technology Data Exchange (ETDEWEB)

    Carr, B J [Cambridge Univ. (UK). Inst. of Astronomy

    1977-04-01

    It is shown that Meszaros theory of galaxy formation, in which galaxies form from the density perturbations associated with the statistical fluctuation in the number density of primordial black holes, must be modified if the black holes are initially surrounded by regions of lower radiation density than average (as is most likely). However, even in this situation, the sort of effect Meszaros envisages does occur and could in principle cause galactic mass-scales to bind at the conventional time. In fact, the requirement that galaxies should not form prematurely implies that black holes could not have a critical density in the mass range above 10/sup 5/ M(sun). If the mass spectrum of primordial black holes falls off more slowly than m/sup -3/ (as expected), then the biggest black holes have the largest clustering effect. In this case the black hole clustering theory of galaxy formation reduces to the black hole seed theory of galaxy formation, in which each galaxy becomes bound under the gravitational influence of a single black hole nucleus. The seed theory could be viable only if the early Universe had a soft equation of state until a time exceeding 10/sup -4/ s or if something prevented black hole formation before 1 s.

  11. Black hole as a wormhole factory

    Directory of Open Access Journals (Sweden)

    Sung-Won Kim

    2015-12-01

    Full Text Available There have been lots of debates about the final fate of an evaporating black hole and the singularity hidden by an event horizon in quantum gravity. However, on general grounds, one may argue that a black hole stops radiation at the Planck mass (ħc/G1/2∼10−5 g, where the radiated energy is comparable to the black hole's mass. And also, it has been argued that there would be a wormhole-like structure, known as “spacetime foam”, due to large fluctuations below the Planck length (ħG/c31/2∼10−33 cm. In this paper, as an explicit example, we consider an exact classical solution which represents nicely those two properties in a recently proposed quantum gravity model based on different scaling dimensions between space and time coordinates. The solution, called “Black Wormhole”, consists of two different states, depending on its mass parameter M and an IR parameter ω: For the black hole state (with ωM2>1/2, a non-traversable wormhole occupies the interior region of the black hole around the singularity at the origin, whereas for the wormhole state (with ωM2<1/2, the interior wormhole is exposed to an outside observer as the black hole horizon is disappearing from evaporation. The black hole state becomes thermodynamically stable as it approaches the merging point where the interior wormhole throat and the black hole horizon merges, and the Hawking temperature vanishes at the exact merge point (with ωM2=1/2. This solution suggests the “Generalized Cosmic Censorship” by the existence of a wormhole-like structure which protects the naked singularity even after the black hole evaporation. One could understand the would-be wormhole inside the black hole horizon as the result of microscopic wormholes created by “negative” energy quanta which have entered the black hole horizon in Hawking radiation process; the quantum black hole could be a wormhole factory! It is found that this speculative picture may be consistent with the

  12. An analysis of the performance of Black African junior provincial ...

    African Journals Online (AJOL)

    been investigated. 1. It was found that these processes were effective in increasing participation of senior black provincial players between. 1996 and 2008. There were ... players were performing at junior provincial level but have not been afforded the ..... batsmen have performed consistently well between 2004 and 2010.

  13. Black string in dRGT massive gravity

    Energy Technology Data Exchange (ETDEWEB)

    Tannukij, Lunchakorn [Mahidol University, Department of Physics, Faculty of Science, Bangkok (Thailand); Hanyang University, Department of Physics, Seoul (Korea, Republic of); Naresuan University, The Institute for Fundamental Study, Phitsanulok (Thailand); Wongjun, Pitayuth [Naresuan University, The Institute for Fundamental Study, Phitsanulok (Thailand); Ministry of Education, Thailand Center of Excellence in Physics, Bangkok (Thailand); Ghosh, Suchant G. [Jamia Millia Islamia, Centre of Theoretical Physics, New Delhi (India); University of Kwazulu-Natal, Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, Durban (South Africa)

    2017-12-15

    We present a cylindrically symmetric solution, both charged and uncharged, which is known as a black string solution to the nonlinear ghost-free massive gravity found by de Rham, Gabadadze, and Tolley (dRGT). This ''dRGT black string'' can be thought of as a generalization of the black string solution found by Lemos. Moreover, the dRGT black string solution includes other classes of black string solution such as the monopole-black string ones since the graviton mass contributes to the global monopole term as well as the cosmological-constant term. To investigate the solution, we compute mass, temperature, and entropy of the dRGT black string. We found that the existence of the graviton mass drastically affects the thermodynamics of the black string. Furthermore, the Hawking-Page phase transition is found to be possible for the dRGT black string as well as the charged dRGT black string. The dRGT black string solution is thermodynamically stable for r > r{sub c} with negative thermodynamical potential and positive heat capacity while it is unstable for r < r{sub c} where the potential is positive. (orig.)

  14. Interior structure of rotating black holes. III. Charged black holes

    International Nuclear Information System (INIS)

    Hamilton, Andrew J. S.

    2011-01-01

    This paper extends to the case of charged rotating black holes the conformally stationary, axisymmetric, conformally separable solutions presented for uncharged rotating black holes in a companion paper. In the present paper, the collisionless fluid accreted by the black hole may be charged. The charge of the black hole is determined self-consistently by the charge accretion rate. As in the uncharged case, hyper-relativistic counterstreaming between ingoing and outgoing streams drives inflation at (just above) the inner horizon, followed by collapse. If both ingoing and outgoing streams are charged, then conformal separability holds during early inflation, but fails as inflation develops. If conformal separability is imposed throughout inflation and collapse, then only one of the ingoing and outgoing streams can be charged: the other must be neutral. Conformal separability prescribes a hierarchy of boundary conditions on the ingoing and outgoing streams incident on the inner horizon. The dominant radial boundary conditions require that the incident ingoing and outgoing number densities be uniform with latitude, but the charge per particle must vary with latitude such that the incident charge densities vary in proportion to the radial electric field. The subdominant angular boundary conditions require specific forms of the incident number- and charge-weighted angular motions. If the streams fall freely from outside the horizon, then the prescribed angular conditions can be achieved by the charged stream, but not by the neutral stream. Thus, as in the case of an uncharged black hole, the neutral stream must be considered to be delivered ad hoc to just above the inner horizon.

  15. Black hole shadow in an asymptotically flat, stationary, and axisymmetric spacetime: The Kerr-Newman and rotating regular black holes

    Science.gov (United States)

    Tsukamoto, Naoki

    2018-03-01

    The shadow of a black hole can be one of the strong observational evidences for stationary black holes. If we see shadows at the center of galaxies, we would say whether the observed compact objects are black holes. In this paper, we consider a formula for the contour of a shadow in an asymptotically-flat, stationary, and axisymmetric black hole spacetime. We show that the formula is useful for obtaining the contour of the shadow of several black holes such as the Kerr-Newman black hole and rotating regular black holes. Using the formula, we can obtain new examples of the contour of the shadow of rotating black holes if assumptions are satisfied.

  16. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  17. The renaissance of black phosphorus.

    Science.gov (United States)

    Ling, Xi; Wang, Han; Huang, Shengxi; Xia, Fengnian; Dresselhaus, Mildred S

    2015-04-14

    One hundred years after its first successful synthesis in the bulk form in 1914, black phosphorus (black P) was recently rediscovered from the perspective of a 2D layered material, attracting tremendous interest from condensed matter physicists, chemists, semiconductor device engineers, and material scientists. Similar to graphite and transition metal dichalcogenides (TMDs), black P has a layered structure but with a unique puckered single-layer geometry. Because the direct electronic band gap of thin film black P can be varied from 0.3 eV to around 2 eV, depending on its film thickness, and because of its high carrier mobility and anisotropic in-plane properties, black P is promising for novel applications in nanoelectronics and nanophotonics different from graphene and TMDs. Black P as a nanomaterial has already attracted much attention from researchers within the past year. Here, we offer our opinions on this emerging material with the goal of motivating and inspiring fellow researchers in the 2D materials community and the broad readership of PNAS to discuss and contribute to this exciting new field. We also give our perspectives on future 2D and thin film black P research directions, aiming to assist researchers coming from a variety of disciplines who are desirous of working in this exciting research field.

  18. Australian black coal statistics 1990

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    This second edition of Australian black coal statistics replaces the Joint Coal Board's publication 'Black coal in Australia'. It includes an expanded international coal trade supplement. Sections cover resources of black coal, coal supply and demand, coal production, employment and productivity of mines, export data, coal consumption and a directory of producers.

  19. Spin One Hawking Radiation from Dirty Black Holes

    OpenAIRE

    Petarpa Boonserm; Tritos Ngampitipan; Matt Visser

    2013-01-01

    A “clean” black hole is a black hole in vacuum such as the Schwarzschild black hole. However in real physical systems, there are matter fields around a black hole. Such a black hole is called a “dirty black hole”. In this paper, the effect of matter fields on the black hole and the greybody factor is investigated. The results show that matter fields make a black hole smaller. They can increase the potential energy to a black hole to obstruct Hawking radiation to propagate. This causes the gre...

  20. Black holes and everyday physics

    International Nuclear Information System (INIS)

    Bekenstein, J.D.

    1982-01-01

    Black holes have piqued much curiosity. But thus far they have been important only in ''remote'' subjects like astrophysics and quantum gravity. It is shown that the situation can be improved. By a judicious application of black hole physics, one can obtain new results in ''everyday physics''. For example, black holes yield a quantum universal upper bound on the entropy-to-energy ratio for ordinary thermodynamical systems which was unknown earlier. It can be checked, albeit with much labor, by ordinary statistical methods. Black holes set a limitation on the number of species of elementary particles-quarks, leptons, neutrinos - which may exist. And black holes lead to a fundamental limitation on the rate at which information can be transferred for given message energy by any communication system. (author)

  1. Black hole final state conspiracies

    International Nuclear Information System (INIS)

    McInnes, Brett

    2009-01-01

    The principle that unitarity must be preserved in all processes, no matter how exotic, has led to deep insights into boundary conditions in cosmology and black hole theory. In the case of black hole evaporation, Horowitz and Maldacena were led to propose that unitarity preservation can be understood in terms of a restriction imposed on the wave function at the singularity. Gottesman and Preskill showed that this natural idea only works if one postulates the presence of 'conspiracies' between systems just inside the event horizon and states at much later times, near the singularity. We argue that some AdS black holes have unusual internal thermodynamics, and that this may permit the required 'conspiracies' if real black holes are described by some kind of sum over all AdS black holes having the same entropy

  2. Gamma ray bursts of black hole universe

    Science.gov (United States)

    Zhang, T. X.

    2015-07-01

    Slightly modifying the standard big bang theory, Zhang recently developed a new cosmological model called black hole universe, which has only a single postulate but is consistent with Mach's principle, governed by Einstein's general theory of relativity, and able to explain existing observations of the universe. In the previous studies, we have explained the origin, structure, evolution, expansion, cosmic microwave background radiation, quasar, and acceleration of black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present state with hundred billion-trillions of solar masses by accreting ambient matter and merging with other black holes. This study investigates gamma ray bursts of black hole universe and provides an alternative explanation for the energy and spectrum measurements of gamma ray bursts according to the black hole universe model. The results indicate that gamma ray bursts can be understood as emissions of dynamic star-like black holes. A black hole, when it accretes its star or merges with another black hole, becomes dynamic. A dynamic black hole has a broken event horizon and thus cannot hold the inside hot (or high-frequency) blackbody radiation, which flows or leaks out and produces a GRB. A star when it collapses into its core black hole produces a long GRB and releases the gravitational potential energy of the star as gamma rays. A black hole that merges with another black hole produces a short GRB and releases a part of their blackbody radiation as gamma rays. The amount of energy obtained from the emissions of dynamic star-like black holes are consistent with the measurements of energy from GRBs. The GRB energy spectra derived from this new emission mechanism are also consistent with the measurements.

  3. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  4. "Styled by Their Perceptions": Black Adolescent Girls Interpret Representations of Black Females in Popular Culture

    Science.gov (United States)

    Muhammad, Gholnecsar E.; McArthur, Sherell A.

    2015-01-01

    Identity formation is a critical process shaping the lives of adolescents and can present distinct challenges for Black adolescent girls who are positioned in society to negotiate ideals of self when presented with false and incomplete images representing Black girlhood. Researchers have found distorted images of Black femininity derived from…

  5. The black church as the womb of black liberation theology?: Why the ...

    African Journals Online (AJOL)

    2015-04-30

    Apr 30, 2015 ... Southern Africa (URCSA) is not a genuine black church? This article ..... peculiar constituency of black slaves and freed men[sic] what no one else was .... church in the USA, which started during the early 20th century when ...

  6. Warped products and black holes

    International Nuclear Information System (INIS)

    Hong, Soon-Tae

    2005-01-01

    We apply the warped product space-time scheme to the Banados-Teitelboim-Zanelli black holes and the Reissner-Nordstroem-anti-de Sitter black hole to investigate their interior solutions in terms of warped products. It is shown that there exist no discontinuities of the Ricci and Einstein curvatures across event horizons of these black holes

  7. Uncovering Black Womanhood in Engineering

    Science.gov (United States)

    Gibson, Sheree L.; Espino, Michelle M.

    2016-01-01

    Despite the growing research that outlines the experiences of Blacks and women undergraduates in engineering, little is known about Black women in this field. The purpose of this qualitative study was to uncover how eight Black undergraduate women in engineering understood their race and gender identities in a culture that can be oppressive to…

  8. Instability of ultra-spinning black holes

    International Nuclear Information System (INIS)

    Emparan, Roberto; Myers, Robert C.

    2003-01-01

    It has long been known that, in higher-dimensional general relativity, there are black hole solutions with an arbitrarily large angular momentum for a fixed mass. We examine the geometry of the event horizon of such ultra-spinning black holes and argue that these solutions become unstable at large enough rotation. Hence we find that higher-dimensional general relativity imposes an effective 'Kerr-bound' on spinning black holes through a dynamical decay mechanism. Our results also give indications of the existence of new stationary black holes with 'rippled' horizons of spherical topology. We consider various scenarios for the possible decay of ultra-spinning black holes, and finally discuss the implications of our results for black holes in braneworld scenarios. (author)

  9. Braneworld black holes and entropy bounds

    Directory of Open Access Journals (Sweden)

    Y. Heydarzade

    2018-01-01

    Full Text Available The Bousso's D-bound entropy for the various possible black hole solutions on a 4-dimensional brane is checked. It is found that the D-bound entropy here is apparently different from that of obtained for the 4-dimensional black hole solutions. This difference is interpreted as the extra loss of information, associated to the extra dimension, when an extra-dimensional black hole is moved outward the observer's cosmological horizon. Also, it is discussed that N-bound entropy is hold for the possible solutions here. Finally, by adopting the recent Bohr-like approach to black hole quantum physics for the excited black holes, the obtained results are written also in terms of the black hole excited states.

  10. Atomic structure in black hole

    International Nuclear Information System (INIS)

    Nagatani, Yukinori

    2006-01-01

    We propose that any black hole has atomic structure in its inside and has no horizon as a model of black holes. Our proposal is founded on a mean field approximation of gravity. The structure of our model consists of a (charged) singularity at the center and quantum fluctuations of fields around the singularity, namely, it is quite similar to that of atoms. Any properties of black holes, e.g. entropy, can be explained by the model. The model naturally quantizes black holes. In particular, we find the minimum black hole, whose structure is similar to that of the hydrogen atom and whose Schwarzschild radius is approximately 1.1287 times the Planck length. Our approach is conceptually similar to Bohr's model of the atomic structure, and the concept of the minimum Schwarzschild radius is similar to that of the Bohr radius. The model predicts that black holes carry baryon number, and the baryon number is rapidly violated. This baryon number violation can be used as verification of the model. (author)

  11. Factors affecting behaviours that address HIV risk among Black and White South Africans

    Directory of Open Access Journals (Sweden)

    K. Peltzer

    2002-09-01

    Full Text Available The aim of this study was to identify factors affecting HIV risk reduction among 150 Black and 150 White South Africans chosen by systematic random sampling. Main outcome measures included sexual behaviour and condom use, knowledge about correct condom use, intention of condom use, behavioural norms, attitudes, normative beliefs, and subjective norms about condoms, HIV/AIDS health beliefs, and HIV risk behaviour. Bivariate analysis gave positive significant relations among being single, age, HIV/ AIDS perceived severity, HIV/AIDS prevention barriers and HIV risk behaviour. Further, bivariate analysis gave negative significant relations among age at onset of puberty, age at first vaginal intercourse, correct condom use knowledge, subjective norms, intention to use condoms and HIV risk behaviour. Regression analysis indicated that for subjective norm to use condoms, less intention for condom use, less condom use knowledge and younger age of first vaginal intercourse were predictive for HIV/AIDS risk behaviour. HIV prevention intervention programmes should include the identified factors and cultural diversity.

  12. Quantum information erasure inside black holes

    International Nuclear Information System (INIS)

    Lowe, David A.; Thorlacius, Larus

    2015-01-01

    An effective field theory for infalling observers in the vicinity of a quasi-static black hole is given in terms of a freely falling lattice discretization. The lattice model successfully reproduces the thermal spectrum of outgoing Hawking radiation, as was shown by Corley and Jacobson, but can also be used to model observations made by a typical low-energy observer who enters the black hole in free fall at a prescribed time. The explicit short distance cutoff ensures that, from the viewpoint of the infalling observer, any quantum information that entered the black hole more than a scrambling time earlier has been erased by the black hole singularity. This property, combined with the requirement that outside observers need at least of order the scrambling time to extract quantum information from the black hole, ensures that a typical infalling observer does not encounter drama upon crossing the black hole horizon in a theory where black hole information is preserved for asymptotic observers.

  13. Determinants and improvement of electrocardiographic diagnosis of left ventricular hypertrophy in a black African population.

    Directory of Open Access Journals (Sweden)

    Ahmadou M Jingi

    Full Text Available BACKGROUND: Left ventricular hypertrophy (LVH is a major cardiovascular risk factor. The electrocardiogram (ECG has been shown to be a poor tool in detecting LVH due to cardiac and extracardiac factors. We studied the determinants and possibility of improving the test performance of the ECG in a group of Black Africans. METHODS: We studied echocardiograms and electrocardiograms of 182 Cameroonian patients among whom 113 (62.1% were having an echocardiographic LVH. Echocardiographic LVH was defined as Left Ventricular Mass Indexed to height 2.7(LVMI>48 g/m2.7 in men, and >44 g/m 2.7 in women or Body Surface Area ≥116 g/m2 in men, and ≥96 g/m2 in women. Test performances were calculated for 6 classic ECG criteria Sokolow-Lyon, Cornell, Cornell product, Gubner-Ungerleiger, amplitudes of R in aVL, V5 and V6. RESULTS: The most sensitive criteria were Cornell (37.2% and Sokolow-Lyon index (26.5%. The most specific criteria were Gubner (98.6%, RaVL (97.1%, RV5/V6 (95.7% and Cornell product (94.2%. The performance of the ECG in diagnosing LVH significantly increased with the severity of LVH for Cornell index (r = 0.420, p<0.0001 and Sokolow index (r = 0.212, p = 0.002. It decreased with body habitus (r = -0.248, p = 0.001 for Sokolow-Lyon index. Cornell index was less affected (age p = 0.766; body habitus: p = 0.209. After sex-specific adjustment for BMI, Cornell BMI sensitivity increased from 37.2% to 69% (r = 0.472, p<0.0001, and Sokolow-Lyon BMI sensitivity increased from 26.5% to 58.4% (r = 0.270, p<0.001. CONCLUSION: The test performance of the ECG in diagnosing LVH is low in this Black African population, due to extracardiac factors such as age, sex, body habitus, and cardiac factors such as LVH severity and geometry. However, this performance is improved after adjustment for extracardiac factors.

  14. Watchable Wildlife: The Black Bear

    Science.gov (United States)

    Lynn L. Rogers

    1992-01-01

    Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

  15. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  16. Improving the Climate for LGBTQ Students at an Historically Black University

    Science.gov (United States)

    Lewis, Marilyn W.; Ericksen, Kirsten S.

    2016-01-01

    African American lesbian, gay, bisexual, transgender, and queer (LGBTQ) students attending an Historically Black College or University (HBCU) may experience bullying. Using snowball sampling, the authors recruited six LGBTQ students for a focus group to learn how they perceived their HBCU campus atmosphere toward LGBTQ students. Thirty faculty…

  17. Geometry of higher-dimensional black hole thermodynamics

    International Nuclear Information System (INIS)

    Aaman, Jan E.; Pidokrajt, Narit

    2006-01-01

    We investigate thermodynamic curvatures of the Kerr and Reissner-Nordstroem (RN) black holes in spacetime dimensions higher than four. These black holes possess thermodynamic geometries similar to those in four-dimensional spacetime. The thermodynamic geometries are the Ruppeiner geometry and the conformally related Weinhold geometry. The Ruppeiner geometry for a d=5 Kerr black hole is curved and divergent in the extremal limit. For a d≥6 Kerr black hole there is no extremality but the Ruppeiner curvature diverges where one suspects that the black hole becomes unstable. The Weinhold geometry of the Kerr black hole in arbitrary dimension is a flat geometry. For the RN black hole the Ruppeiner geometry is flat in all spacetime dimensions, whereas its Weinhold geometry is curved. In d≥5 the Kerr black hole can possess more than one angular momentum. Finally we discuss the Ruppeiner geometry for the Kerr black hole in d=5 with double angular momenta

  18. Ain't I Black Too: Counterstories of Black Atheists in College

    Science.gov (United States)

    Snipes, Jeremy T.

    2017-01-01

    Increasingly Black college students are identifying as atheist, however few empirical studies in higher education and student affairs are exploring the phenomenon. This dissertation examines the question, "How do Black atheist understand their identity in college?" Using Higginbotham's Politics of Respectability and tenants of Critical…

  19. Statistical Hair on Black Holes

    International Nuclear Information System (INIS)

    Strominger, A.

    1996-01-01

    The Bekenstein-Hawking entropy for certain BPS-saturated black holes in string theory has recently been derived by counting internal black hole microstates at weak coupling. We argue that the black hole microstate can be measured by interference experiments even in the strong coupling region where there is clearly an event horizon. Extracting information which is naively behind the event horizon is possible due to the existence of statistical quantum hair carried by the black hole. This quantum hair arises from the arbitrarily large number of discrete gauge symmetries present in string theory. copyright 1996 The American Physical Society

  20. On black hole horizon fluctuations

    International Nuclear Information System (INIS)

    Tuchin, K.L.

    1999-01-01

    A study of the high angular momentum particles 'atmosphere' near the Schwarzschild black hole horizon suggested that strong gravitational interactions occur at invariant distance of the order of 3 √M [2]. We present a generalization of this result to the Kerr-Newman black hole case. It is shown that the larger charge and angular momentum black hole bears, the larger invariant distance at which strong gravitational interactions occur becomes. This invariant distance is of order 3 √((r + 2 )/((r + - r - ))). This implies that the Planckian structure of the Hawking radiation of extreme black holes is completely broken

  1. Thermodynamics of Accelerating Black Holes.

    Science.gov (United States)

    Appels, Michael; Gregory, Ruth; Kubizňák, David

    2016-09-23

    We address a long-standing problem of describing the thermodynamics of an accelerating black hole. We derive a standard first law of black hole thermodynamics, with the usual identification of entropy proportional to the area of the event horizon-even though the event horizon contains a conical singularity. This result not only extends the applicability of black hole thermodynamics to realms previously not anticipated, it also opens a possibility for studying novel properties of an important class of exact radiative solutions of Einstein equations describing accelerated objects. We discuss the thermodynamic volume, stability, and phase structure of these black holes.

  2. Black Political Socialization and Political Change: The Black Panther Party Platform as a "Model" of Radical Political Socialization

    Science.gov (United States)

    McLemore, Leslie Burl

    1975-01-01

    Considers the potential impact of black revolutionary nationalism--cultural and military--upon the social patterns of black people, arguing that a racial, cultural, and military approach through black organizations with a highly developed system of communications holds the key to black salvation in America. (Author/JM)

  3. Compressibility of rotating black holes

    International Nuclear Information System (INIS)

    Dolan, Brian P.

    2011-01-01

    Interpreting the cosmological constant as a pressure, whose thermodynamically conjugate variable is a volume, modifies the first law of black hole thermodynamics. Properties of the resulting thermodynamic volume are investigated: the compressibility and the speed of sound of the black hole are derived in the case of nonpositive cosmological constant. The adiabatic compressibility vanishes for a nonrotating black hole and is maximal in the extremal case--comparable with, but still less than, that of a cold neutron star. A speed of sound v s is associated with the adiabatic compressibility, which is equal to c for a nonrotating black hole and decreases as the angular momentum is increased. An extremal black hole has v s 2 =0.9 c 2 when the cosmological constant vanishes, and more generally v s is bounded below by c/√(2).

  4. Black-hole creation in quantum cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Chao, Wu [Rome, Univ. `La Sapienza` (Italy). International Center for Relativistic Astrophysics]|[Specola Vaticana, Vatican City State (Vatican City State, Holy See)

    1997-11-01

    It is proven that the probability of a black hole created from the de Sitter space-time background, at the Wkb level, is the exponential of one quarter of the sum of the black hole and cosmological horizon areas, or the total entropy of the universe. This is true not only for the spherically symmetric cases of the Schwarzschild or Reissner-Nordstroem black holes, but also for the rotating cases of the Kerr black hole and the rotating charged case of the Newman black hole. The de Sitter metric is the most probable evolution at the Planckian era of the universe.

  5. The dining and tipping behaviour of Black South Africans: a ...

    African Journals Online (AJOL)

    To target potential black diners, a visitor survey was conducted at the Cape Town International Jazz Festival. A total of 256 usable questionnaires were returned and included in the analysis. Socialisation, gastronomy enjoyment, lifestyle and escape and status were identifi ed as the four motives for dining out. Based on ...

  6. Does whole-cell pertussis vaccine protect black South African infants?

    African Journals Online (AJOL)

    The whole-cell pertussis vaccine currently used in South Africa has not been adequately evaluated for post-vaccination events and immunogenicity. A trial of this vaccine combined with diphtheria and tetanus toxoids (DTP) was undertaken in 115 black babies who received primary vaccination at 2, 4 and 6 months of age.

  7. Beyoncé’s Slay Trick: The Performance of Black Camp and its Intersectional Politics

    OpenAIRE

    Chatzipapatheodoridis Constantine

    2017-01-01

    This article pays attention to African-American artist Beyonce Knowles and her performance of black camp. Beyonce’s stage persona and performances invite multiple ideological readings as to what pertains to her interpretation of gender, sexuality, and race. While cultural theory around the icon of Beyonce has focused on her feminist and racial politics as well as her politicization of the black female body, a queer reading applied from the perspective of camp performance will concentrate on t...

  8. Within-group Ethnic Differences of Black Male STEM Majors and Factors Affecting Their Persistence in College

    Directory of Open Access Journals (Sweden)

    Shane Y. Williamson

    2010-04-01

    Full Text Available The present study examined how familial and institutional factors interact with the academic experiences of a diverse group of Black males enrolled as science, technology, engineering, and mathematics (STEM majors at one university. Ogbu’s (1998 Cultural-Ecological Theory of Minority School Performance, a theoretical framework, posits that the manner by which a group achieves minority status, coupled with community and family educational values, impacts academic achievement. Immigrants, voluntary minorities, perform better academically than involuntary minorities (nonimmigrants because they are more accepting of and more likely to adapt to the White middle-class norms upon which schools in the United States are based (Ogbu, 1994, 2004. While the data overall are positive for the sample, when viewed by ethnic group, it was evident the African and Caribbean students are more academically integrated to campus than African American students. The African students, more so than any other ethnic group, are connecting, interacting, and forming relationships with faculty outside of the classroom; conversely, African American students in this study reported having the least amount of effective connections with faculty. This research study found that for the Black male STEM students in this project (a their families are a pivotal force, (b academic experiences vary across ethnicities, (c faculty mediate student success, and (d there is a lack of interactions between ethnic groups (Black Distance on campus.

  9. Six-dimensional localized black holes: Numerical solutions

    International Nuclear Information System (INIS)

    Kudoh, Hideaki

    2004-01-01

    To test the strong-gravity regime in Randall-Sundrum braneworlds, we consider black holes bound to a brane. In a previous paper, we studied numerical solutions of localized black holes whose horizon radii are smaller than the AdS curvature radius. In this paper, we improve the numerical method and discuss properties of the six-dimensional (6D) localized black holes whose horizon radii are larger than the AdS curvature radius. At a horizon temperature T≅1/2πl, the thermodynamics of the localized black hole undergo a transition with its character changing from a 6D Schwarzschild black hole type to a 6D black string type. The specific heat of the localized black holes is negative, and the entropy is greater than or nearly equal to that of the 6D black strings with the same thermodynamic mass. The large localized black holes show flattened horizon geometries, and the intrinsic curvature of the horizon four-geometry becomes negative near the brane. Our results indicate that the recovery mechanism of lower-dimensional Einstein gravity on the brane works even in the presence of the black holes

  10. Black holes with halos

    Science.gov (United States)

    Monten, Ruben; Toldo, Chiara

    2018-02-01

    We present new AdS4 black hole solutions in N =2 gauged supergravity coupled to vector and hypermultiplets. We focus on a particular consistent truncation of M-theory on the homogeneous Sasaki–Einstein seven-manifold M 111, characterized by the presence of one Betti vector multiplet. We numerically construct static and spherically symmetric black holes with electric and magnetic charges, corresponding to M2 and M5 branes wrapping non-contractible cycles of the internal manifold. The novel feature characterizing these nonzero temperature configurations is the presence of a massive vector field halo. Moreover, we verify the first law of black hole mechanics and we study the thermodynamics in the canonical ensemble. We analyze the behavior of the massive vector field condensate across the small-large black hole phase transition and we interpret the process in the dual field theory.

  11. BlackBerry All-in-One for Dummies

    CERN Document Server

    Sarigumba, Dante; Petz, William

    2010-01-01

    Go beyond BlackBerry basics and get everything your BlackBerry can deliver. BlackBerry is the leading smartphone for business users, and its popularity continues to explode. When you discover the amazing array of BlackBerry possibilities in this fun and friendly guide, you'll be even happier with your choice of smartphones. BlackBerry All-in-One For Dummies explores every feature and application common to all BlackBerry devices. It explains the topics in depth, with tips, tricks, workarounds, and includes detailed information about cool new third-party applications, accessories, and downloads

  12. Instability of charged anti-de Sitter black holes

    International Nuclear Information System (INIS)

    Gwak, Bogeun; Lee, Bum-Hoon; Ro, Daeho

    2016-01-01

    We have studied the instability of charged anti-de Sitter black holes in four- or higher-dimensions under fragmentation. The unstable black holes under fragmentation can be broken into two black holes. Instability depends not only on the mass and charge of the black hole but also on the ratio between the fragmented black hole and its predecessor. We have found that the near extremal black holes are unstable, and Schwarzschild-AdS black holes are stable. These are qualitatively similar to black holes in four dimensions and higher. The detailed instabilities are numerically investigated.

  13. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  14. Black Films and Film-Makers.

    Science.gov (United States)

    Patterson, Lindsay, Ed.

    The development of black films and the attitudes of the film industry toward black films and black actors are some of the topics examined in this anthology of essays. Section 1, "Nigger to Supernigger," contains such articles as "The Death of Rastus: Negroes in American Films" by Thomas R. Cripps and "Folk Values in a New Medium" by Alain Locke…

  15. Perceptions relating to body size, weight loss and weight-loss interventions in black South African women: a qualitative study.

    Science.gov (United States)

    Draper, Catherine E; Davidowitz, Kesiah J; Goedecke, Julia H

    2016-02-01

    A higher tolerance for a larger body size has been associated with obesity in black South African (SA) women. The aim of the present study was to explore perceptions regarding body size and weight loss in a sample of black women from a low-income community in Cape Town, SA. Qualitative pilot study including five focus groups. Data were analysed using thematic analysis. Khayelitsha, Cape Town, SA. Twenty-one black SA women. The majority of participants had positive perceptions of overweight/obesity, which were influenced by community and cultural perceptions, but some inconsistencies were observed as overweight/obesity was also associated with ill health. Participants identified many benefits to weight loss, but due to the association with sickness, they were concerned about being stigmatised in their community. Although participants had knowledge about healthy eating, the main barrier to eating healthily included the perceived higher cost of healthier food and food insecurity. All participants saw exercise as a strategy to lose weight and improve health, and were interested in participating in a community-based exercise intervention, but negative community perceptions and conflicting views regarding who should lead the intervention were identified as barriers. These findings highlight the complexities surrounding participants' perceptions regarding body size, weight loss and weight-loss interventions, and emphasise low socio-economic status as a barrier to change. The study also highlights the strong influence of cultural ideals and community perceptions on personal perceptions. These findings underscore the necessity for culturally appropriate weight-loss interventions in low-income, transitioning communities.

  16. “Nothing Better or Worse than Being Black, Gay, and in the Band”: A Qualitative Examination of Gay Undergraduates Participating in Historically Black College or University Marching Bands

    Science.gov (United States)

    Carter, Bruce Allen

    2013-01-01

    This collective case study examined the experiences of four African American gay band students attending historically Black colleges or universities (HCBUs) in the southern United States. This study explored influences that shaped the participants' identities as they negotiated numerous complex sociocultural discourses pervasive and challenging to…

  17. The Relationship between Black Racial Identity and Academic Achievement in Urban Settings

    Science.gov (United States)

    Harper, Brian E.

    2007-01-01

    This article examines the relationship between Black racial identity and academic achievement in urban settings. Using Mary Shelley's Frankenstein (1918) as a comparative framework, the author describes current practices and suggests practical applications of empirical findings for practicing classroom teachers of African American students.…

  18. Physical Activity Behaviors of Students of a Rural Historically Black College

    Science.gov (United States)

    Kemper, Karen A.; Welsh, Ralph S.

    2010-01-01

    Physical activity can have a positive impact on health disparities among African Americans. Objective: In this study, we assessed physical activity behaviors and correlates of students of a Historically Black College. Methods: In September 2004, an online survey and pedometers were used to measure physical activity behavior and correlates.…

  19. Black holes and cosmic censorship

    International Nuclear Information System (INIS)

    Hiscock, W.A.

    1979-01-01

    It is widely accepted that the complete gravitational collapse of a body always yields a black hole, and that naked singularities are never produced (the cosmic censorship hypothesis). The local (or strong) cosmic censorship hypothesis states that singularities which are even locally naked (e.g., to an observer inside a black hole) are never produced. This dissertation studies the validity of these two conjectures. The Kerr-Newman metrics describes the black holes only when M 2 greater than or equal to Q 2 + P 2 , where M is the mass of the black hole, a = J/M its specific angular momentum, Q its electric charge, and P its magnetic charge. In the first part of this dissertation, the possibility of converting an extreme Kerr-Newman black hole (M 2 = a 2 + Q 2 + P 2 ) into a naked singularity by the accretion of test particles is considered. The motion of test particles is studied with a large angular momentum to energy ratio, and also test particles with a large charge to energy ratio. The final state is always found to be a black hole if the angular momentum, electric charge, and magnetic charge of the black hole are all much greater than the corresponding angular momentum, electric charge, and magnetic charge of the test particle. In Part II of this dissertation possible black hole interior solutions are studied. The Cauchy horizons and locally naked timelike singularities of the charged (and/or rotating) solutions are contrasted with the spacelike all-encompassing singularity of the Schwarzschild solution. It is determined which portions of the analytic extension of the Reissner-Nordstroem solution are relevant to realistic gravitational collapse

  20. Selective coating for solar panels. [using black chrome and black nickel

    Science.gov (United States)

    Mcdonald, G. E. (Inventor)

    1977-01-01

    The energy absorbing properties of solar heating panels are improved by depositing a black chrome coating of controlled thickness on a specially prepared surface of a metal substrate. The surface is prepared by depositing a dull nickel on the substrate, and the black chrome is plated on this low emittance surface to a thickness between 0.5 micron and 2.5 microns.

  1. Quantum capacity of quantum black holes

    Science.gov (United States)

    Adami, Chris; Bradler, Kamil

    2014-03-01

    The fate of quantum entanglement interacting with a black hole has been an enduring mystery, not the least because standard curved space field theory does not address the interaction of black holes with matter. We discuss an effective Hamiltonian of matter interacting with a black hole that has a precise analogue in quantum optics and correctly reproduces both spontaneous and stimulated Hawking radiation with grey-body factors. We calculate the quantum capacity of this channel in the limit of perfect absorption, as well as in the limit of a perfectly reflecting black hole (a white hole). We find that the white hole is an optimal quantum cloner, and is isomorphic to the Unruh channel with positive quantum capacity. The complementary channel (across the horizon) is entanglement-breaking with zero capacity, avoiding a violation of the quantum no-cloning theorem. The black hole channel on the contrary has vanishing capacity, while its complement has positive capacity instead. Thus, quantum states can be reconstructed faithfully behind the black hole horizon, but not outside. This work sheds new light on black hole complementarity because it shows that black holes can both reflect and absorb quantum states without violating the no-cloning theorem, and makes quantum firewalls obsolete.

  2. Black Edens, country Eves: Listening, performance, and black queer longing in country music.

    Science.gov (United States)

    Royster, Francesca T

    2017-07-03

    This article explores Black queer country music listening, performance, and fandom as a source of pleasure, nostalgia, and longing for Black listeners. Country music can be a space for alliance and community, as well as a way of accessing sometimes repressed cultural and personal histories of violence: lynching and other forms of racial terror, gender surveillance and disciplining, and continued racial and economic segregation. For many Black country music listeners and performers, the experience of being a closeted fan also fosters an experience of ideological hailing, as well as queer world-making. Royster suggests that through Black queer country music fandom and performance, fans construct risky and soulful identities. The article uses Tina Turner's solo album, Tina Turns the Country On! (1974) as an example of country music's power as a tool for resistance to racial, sexual, and class disciplining.

  3. Entropy of black holes with multiple horizons

    Science.gov (United States)

    He, Yun; Ma, Meng-Sen; Zhao, Ren

    2018-05-01

    We examine the entropy of black holes in de Sitter space and black holes surrounded by quintessence. These black holes have multiple horizons, including at least the black hole event horizon and a horizon outside it (cosmological horizon for de Sitter black holes and "quintessence horizon" for the black holes surrounded by quintessence). Based on the consideration that the two horizons are not independent each other, we conjecture that the total entropy of these black holes should not be simply the sum of entropies of the two horizons, but should have an extra term coming from the correlations between the two horizons. Different from our previous works, in this paper we consider the cosmological constant as the variable and employ an effective method to derive the explicit form of the entropy. We also try to discuss the thermodynamic stabilities of these black holes according to the entropy and the effective temperature.

  4. Black hole entropy, curved space and monsters

    International Nuclear Information System (INIS)

    Hsu, Stephen D.H.; Reeb, David

    2008-01-01

    We investigate the microscopic origin of black hole entropy, in particular the gap between the maximum entropy of ordinary matter and that of black holes. Using curved space, we construct configurations with entropy greater than the area A of a black hole of equal mass. These configurations have pathological properties and we refer to them as monsters. When monsters are excluded we recover the entropy bound on ordinary matter S 3/4 . This bound implies that essentially all of the microstates of a semiclassical black hole are associated with the growth of a slightly smaller black hole which absorbs some additional energy. Our results suggest that the area entropy of black holes is the logarithm of the number of distinct ways in which one can form the black hole from ordinary matter and smaller black holes, but only after the exclusion of monster states

  5. Black-hole bomb and superradiant instabilities

    International Nuclear Information System (INIS)

    Cardoso, Vitor; Dias, Oscar J.C.; Lemos, Jose P.S.; Yoshida, Shijun

    2004-01-01

    A wave impinging on a Kerr black hole can be amplified as it scatters off the hole if certain conditions are satisfied, giving rise to superradiant scattering. By placing a mirror around the black hole one can make the system unstable. This is the black-hole bomb of Press and Teukolsky. We investigate in detail this process and compute the growing time scales and oscillation frequencies as a function of the mirror's location. It is found that in order for the system black hole plus mirror to become unstable there is a minimum distance at which the mirror must be located. We also give an explicit example showing that such a bomb can be built. In addition, our arguments enable us to justify why large Kerr-AdS black holes are stable and small Kerr-AdS black holes should be unstable

  6. Black holes escaping from domain walls

    International Nuclear Information System (INIS)

    Flachi, Antonino; Sasaki, Misao; Pujolas, Oriol; Tanaka, Takahiro

    2006-01-01

    Previous studies concerning the interaction of branes and black holes suggested that a small black hole intersecting a brane may escape via a mechanism of reconnection. Here we consider this problem by studying the interaction of a small black hole and a domain wall composed of a scalar field and simulate the evolution of this system when the black hole acquires an initial recoil velocity. We test and confirm previous results, however, unlike the cases previously studied, in the more general set-up considered here, we are able to follow the evolution of the system also during the separation, and completely illustrate how the escape of the black hole takes place

  7. Black Holes Have Simple Feeding Habits

    Science.gov (United States)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  8. Measuring the spins of accreting black holes

    International Nuclear Information System (INIS)

    McClintock, Jeffrey E; Narayan, Ramesh; Gou, Lijun; Kulkarni, Akshay; Penna, Robert F; Steiner, James F; Davis, Shane W; Orosz, Jerome A; Remillard, Ronald A

    2011-01-01

    A typical galaxy is thought to contain tens of millions of stellar-mass black holes, the collapsed remnants of once massive stars, and a single nuclear supermassive black hole. Both classes of black holes accrete gas from their environments. The accreting gas forms a flattened orbiting structure known as an accretion disk. During the past several years, it has become possible to obtain measurements of the spins of the two classes of black holes by modeling the x-ray emission from their accretion disks. Two methods are employed, both of which depend upon identifying the inner radius of the accretion disk with the innermost stable circular orbit, whose radius depends only on the mass and spin of the black hole. In the Fe Kα method, which applies to both classes of black holes, one models the profile of the relativistically broadened iron line with a special focus on the gravitationally redshifted red wing of the line. In the continuum-fitting (CF) method, which has so far only been applied to stellar-mass black holes, one models the thermal x-ray continuum spectrum of the accretion disk. We discuss both methods, with a strong emphasis on the CF method and its application to stellar-mass black holes. Spin results for eight stellar-mass black holes are summarized. These data are used to argue that the high spins of at least some of these black holes are natal, and that the presence or absence of relativistic jets in accreting black holes is not entirely determined by the spin of the black hole.

  9. Quantum black holes

    OpenAIRE

    Hooft, G. 't

    1987-01-01

    This article is divided into three parts. First, a systematic derivation of the Hawking radiation is given in three different ways. The information loss problem is then discussed in great detail. The last part contains a concise discussion of black hole thermodynamics. This article was published as chapter $6$ of the IOP book "Lectures on General Relativity, Cosmology and Quantum Black Holes" (July $2017$).

  10. Notes on Phase Transition of Nonsingular Black Hole

    International Nuclear Information System (INIS)

    Ma Meng-Sen; Zhao Ren

    2015-01-01

    On the belief that a black hole is a thermodynamic system, we study the phase transition of nonsingular black holes. If the black hole entropy takes the form of the Bekenstein—Hawking area law, the black hole mass M is no longer the internal energy of the black hole thermodynamic system. Using the thermodynamic quantities, we calculate the heat capacity, thermodynamic curvature and free energy. It is shown that there will be a larger black hole/smaller black hole phase transition for the nonsingular black hole. At the critical point, the second-order phase transition appears. (paper)

  11. Bosonic instability of charged black holes

    International Nuclear Information System (INIS)

    Gaina, A.B.; Ternov, I.M.

    1986-01-01

    The processes of spontaneous and induced production and accumulation of charged bosons on quasibound superradiant levels in the field of Kerr-Newman black hole is analysed. It is shown that bosonic instability may be caused exclusively by the rotation of the black hole. Particulary, the Reissner-Nordstrom configuration is stable. In the case of rotating and charged black hole the bosonic instability may cause an increase of charge of the black hole

  12. Magnetohydrodynamics near a black hole

    International Nuclear Information System (INIS)

    Wilson, J.R.

    1975-01-01

    A numerical computer study of hydromagnetic flow near a black hole is presented. First, the equations of motion are developed to a form suitable for numerical computations. Second, the results of calculations describing the magnetic torques exerted by a rotating black hole on a surrounding magnetic plasma and the electric charge that is induced on the surface of the black hole are presented. (auth)

  13. Young, Black, and Sentenced To Die: Black Males and the Death Penalty.

    Science.gov (United States)

    Joseph, Janice

    1996-01-01

    Explores the death penalty as imposed on young black males in the United States and examines the disparity in death penalty rates for homicides with black offenders and white victims. States continue to impose the death penalty rather than viewing youth violence as a failure of the social system. (SLD)

  14. Sizes of Black Holes Throughout the Universe

    Science.gov (United States)

    Kohler, Susanna

    2018-05-01

    What is the distribution of sizes of black holes in our universe? Can black holes of any mass exist, or are there gaps in their possible sizes? The shape of this black-hole mass function has been debated for decades and the dawn of gravitational-wave astronomy has only spurred further questions.Mind the GapsThe starting point for the black-hole mass function lies in the initial mass function (IMF) for stellar black holes the beginning size distribution of black holes after they are born from stars. Instead of allowing for the formation of stellar black holes of any mass, theoretical models propose two gaps in the black-hole IMF:An upper mass gap at 50130 solar masses, due to the fact that stellar progenitors of black holes in this mass range are destroyed by pair-instability supernovae.A lower mass gap below 5 solar masses, which is argued to arise naturally from the mechanics of supernova explosions.Missing black-hole (BH) formation channels due to the existence of the lower gap (LG) and the upper gap (UG) in the initial mass function. a) The number of BHs at all scales are lowered because no BH can merge with BHs in the LG to form a larger BH. b) The missing channel responsible for the break at 10 solar masses, resulting from the LG. c) The missing channel responsible for the break at 60 solar masses, due to the interaction between the LG and the UG. [Christian et al. 2018]We can estimate the IMF for black holes by scaling a typical IMF for stars and then adding in these theorized gaps. But is this initial distribution of black-hole masses the same as the distribution that we observe in the universe today?The Influence of MergersBased on recent events, the answer appears to be no! Since the first detections of gravitational waves in September 2015, we now know that black holes can merge to form bigger black holes. An initial distribution of black-hole masses must therefore evolve over time, as mergers cause the depletion of low-mass black holes and an increase in

  15. BlackBerry for Work Productivity for Professionals

    CERN Document Server

    Mittal, K

    2010-01-01

    The BlackBerry is cool, and the BlackBerry is fun, but the BlackBerry also means serious business. For those of you who bought your BlackBerry to help get your life organized and free yourself from the ball-and-chain of desktop computing, BlackBerry at Work: Productivity for Professionals is the book to show you how. There are plenty of general-purpose BlackBerry guides, but this book shows you how to complete all the traditional smartphone tasks, like to-dos, calendars, and email, and become even more efficient and productive. You'll learn mechanisms for developing effective workflows specifi

  16. A Tale of Two O's: Odysseus and Oedipus in the Black Atlantic

    Directory of Open Access Journals (Sweden)

    Emily Greenwood

    2009-12-01

    Full Text Available [First paragraphs] Crossroads in the Black Aegean: Oedipus, Antigone, and Dramas of the African Diaspora. Barbara Goff & Michael Simpson. Oxford: Oxford University Press, 2007. xii + 401 pp. (Cloth US$ 150.00 Romare Bearden: A Black Odyssey. Robert G. O’Meally. New York: DC Moore Gallery, 2007. 116 pp. (Cloth$ 45.00 Commenting on cultural imperialism under European colonialism, Frantz Fanon (1990:39 remarked that “The settler makes history; his life is an epoch, an Odyssey.” In Fanon’s analysis the settler’s sense of history derived from the history of the “mother country,” rather than the history of the colony that he or she inhabited. But history did not stop here: the reference to the Odyssey reminds us that behind the modern colonial metropolis was a fictional line of descent reaching back to a Greco-Roman cradle, such that the European settler could lay claim to an even more ancient cultural inheritance. The two books examined here make short work of these classical imperial fictions; O’Meally demonstrates how Romare Bearden’s collages of the Odyssey collaborate with Homer, jazz style, to produce an epic that Black America can recognize as its own. If the voyage of Odysseus is sometimes taken to symbolize the migration of ancient Greek civilization toward the West, Barbara Goff and Michael Simpson interject the troubled figure of Oedipus, who plays Poseidon to the settler’s Odyssey, disrupting the voyage and confusing the trajectory (p. 268. Both studies are timely and speak to a wave of recent research on Black Classicism – an examination of the work to which the classical tradition has been put in Africa and the African diaspora, ranging from the hegemonic appropriation of Classics by colonizers and slave-owners to the use of Classics as an ironic counterdiscourse that writes back to racism and imperialism, or as a source of mythopoiesis in the formation of modern black identity.

  17. BOOK REVIEW: Introduction to Black Hole Physics Introduction to Black Hole Physics

    Science.gov (United States)

    Tanaka, Takahiro

    2012-07-01

    Introduction to Black Hole Physics is a large volume (504 pages), and yet despite this it is still really an introductory text. The book gives an introduction to general relativity, but most of the text is dedicated to attracting the reader's attention to the interesting world of black hole physics. In this sense, the book is very distinct from other textbooks on general relativity. We are told that it was based on the lectures given by Professor Frolov, one of the authors, over the last 30 years. One can obtain the basic ideas about black holes, and also the necessary tips to understand general relativity at a very basic level. For example, in the discussion about particle motion in curved space, the authors start with a brief review on analytical mechanics. The book does not require its readers to have a great deal of knowledge in advance. If you are familiar with such a basic subject, you can simply omit that section. The reason why I especially picked up on this topic as an example is that the book devotes a significant number of pages to geodesic motions in black hole spacetime. One of the main motivations to study black holes is related to how they will actually be observed, once we develop the ability to observe them clearly. The book does explain such discoveries as, for instance, how the motion of a particle is related to a beautiful mathematical structure arising from the hidden symmetry of spacetime, which became transparent via the recent progress in the exploration of black holes in higher dimensions; a concise introduction to this latest topic is deferred to Appendix D, so as not to distract the reader with its mathematical complexities. It should be also mentioned that the book is not limited to general relativistic aspects: quantum fields on a black hole background and Hawking radiation are also covered. Also included are current hot topics, for instance the gravitational waves from a system including black holes, whose first direct detection is

  18. Black Hole Paradoxes

    International Nuclear Information System (INIS)

    Joshi, Pankaj S.; Narayan, Ramesh

    2016-01-01

    We propose here that the well-known black hole paradoxes such as the information loss and teleological nature of the event horizon are restricted to a particular idealized case, which is the homogeneous dust collapse model. In this case, the event horizon, which defines the boundary of the black hole, forms initially, and the singularity in the interior of the black hole at a later time. We show that, in contrast, gravitational collapse from physically more realistic initial conditions typically leads to the scenario in which the event horizon and space-time singularity form simultaneously. We point out that this apparently simple modification can mitigate the causality and teleological paradoxes, and also lends support to two recently suggested solutions to the information paradox, namely, the ‘firewall’ and ‘classical chaos’ proposals. (paper)

  19. Merging Black Holes

    Science.gov (United States)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  20. Cosmic microwave background radiation of black hole universe

    Science.gov (United States)

    Zhang, T. X.

    2010-11-01

    Modifying slightly the big bang theory, the author has recently developed a new cosmological model called black hole universe. This new cosmological model is consistent with the Mach principle, Einsteinian general theory of relativity, and observations of the universe. The origin, structure, evolution, and expansion of the black hole universe have been presented in the recent sequence of American Astronomical Society (AAS) meetings and published recently in a scientific journal: Progress in Physics. This paper explains the observed 2.725 K cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present universe with hundred billion-trillions of solar masses. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which can be considered as an ideal black body. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down. A governing equation that expresses the possible thermal history of the black hole universe is derived from the Planck law of black body radiation and radiation energy conservation. The result obtained by solving the governing equation indicates that the radiation temperature of the present universe can be ˜2.725 K if the universe originated from a hot star-like black hole, and is therefore consistent with the observation of the cosmic microwave background radiation. A smaller or younger black hole universe usually cools down faster. The characteristics of the original star-like or supermassive black hole are not critical to the physical properties of the black hole universe at present, because matter and radiation are mainly from the outside space, i.e., the mother universe.

  1. Black holes at neutrino telescopes

    International Nuclear Information System (INIS)

    Kowalski, M.; Ringwald, A.; Tu, H.

    2002-01-01

    In scenarios with extra dimensions and TeV-scale quantum gravity, black holes are expected to be produced in the collision of light particles at center-of-mass energies above the fundamental Planck scale with small impact parameters. Black hole production and evaporation may thus be studied in detail at the large hadron collider (LHC). But even before the LHC starts operating, neutrino telescopes such as AMANDA/IceCube, ANTARES, Baikal, and RICE have an opportunity to search for black hole signatures. Black hole production in the scattering of ultrahigh energy cosmic neutrinos on nucleons in the ice or water may initiate cascades and through-going muons with distinct characteristics above the Standard Model rate. In this Letter, we investigate the sensitivity of neutrino telescopes to black hole production and compare it to the one expected at the Pierre Auger Observatory, an air shower array currently under construction, and at the LHC. We find that, already with the currently available data, AMANDA and RICE should be able to place sensible constraints in black hole production parameter space, which are competitive with the present ones from the air shower facilities Fly's Eye and AGASA. In the optimistic case that a ultrahigh energy cosmic neutrino flux significantly higher than the one expected from cosmic ray interactions with the cosmic microwave background radiation is realized in nature, one even has discovery potential for black holes at neutrino telescopes beyond the reach of LHC. (orig.)

  2. Accretion, primordial black holes and standard cosmology

    Indian Academy of Sciences (India)

    Primordial black holes evaporate due to Hawking radiation. We find that the evaporation times of primordial black holes increase when accretion of radiation is included. Thus, depending on accretion efficiency, more primordial black holes are existing today, which strengthens the conjecture that the primordial black holes ...

  3. Retaining Black Teachers: An Examination of Black Female Teachers' Intentions to Remain in K-12 Classrooms

    Science.gov (United States)

    Farinde, Abiola A.; Allen, Ayana; Lewis, Chance W.

    2016-01-01

    Sixty years after "Brown v. Board of Education," retention trends indicate that there is a Black teacher shortage. Research shows that Black teachers' retention rates are often lower than the retention rates of White teachers. Black teachers report low salaries, lack of administrative support, and other school variables as reasons for…

  4. Do stringy corrections stabilize colored black holes?

    International Nuclear Information System (INIS)

    Kanti, P.; Winstanley, E.

    2000-01-01

    We consider hairy black hole solutions of Einstein-Yang-Mills-dilaton theory, coupled to a Gauss-Bonnet curvature term, and we study their stability under small, spacetime-dependent perturbations. We demonstrate that stringy corrections do not remove the sphaleronic instabilities of colored black holes with the number of unstable modes being equal to the number of nodes of the background gauge function. In the gravitational sector and in the limit of an infinitely large horizon, colored black holes are also found to be unstable. Similar behavior is exhibited by magnetically charged black holes while the bulk of neutral black holes are proved to be stable under small, gauge-dependent perturbations. Finally, electrically charged black holes are found to be characterized only by the existence of a gravitational sector of perturbations. As in the case of neutral black holes, we demonstrate that for the bulk of electrically charged black holes no unstable modes arise in this sector. (c) 2000 The American Physical Society

  5. Mass inflation in the loop black hole

    International Nuclear Information System (INIS)

    Brown, Eric G.; Mann, Robert; Modesto, Leonardo

    2011-01-01

    In classical general relativity the Cauchy horizon within a two-horizon black hole is unstable via a phenomenon known as mass inflation, in which the mass parameter (and the spacetime curvature) of the black hole diverges at the Cauchy horizon. Here we study this effect for loop black holes - quantum gravitationally corrected black holes from loop quantum gravity - whose construction alleviates the r=0 singularity present in their classical counterparts. We use a simplified model of mass inflation, which makes use of the generalized Dray-'t Hooft relation, to conclude that the Cauchy horizon of loop black holes indeed results in a curvature singularity similar to that found in classical black holes. The Dray-'t Hooft relation is of particular utility in the loop black hole because it does not directly rely upon Einstein's field equations. We elucidate some of the interesting and counterintuitive properties of the loop black hole, and corroborate our results using an alternate model of mass inflation due to Ori.

  6. Entropy of black holes with multiple horizons

    Directory of Open Access Journals (Sweden)

    Yun He

    2018-05-01

    Full Text Available We examine the entropy of black holes in de Sitter space and black holes surrounded by quintessence. These black holes have multiple horizons, including at least the black hole event horizon and a horizon outside it (cosmological horizon for de Sitter black holes and “quintessence horizon” for the black holes surrounded by quintessence. Based on the consideration that the two horizons are not independent each other, we conjecture that the total entropy of these black holes should not be simply the sum of entropies of the two horizons, but should have an extra term coming from the correlations between the two horizons. Different from our previous works, in this paper we consider the cosmological constant as the variable and employ an effective method to derive the explicit form of the entropy. We also try to discuss the thermodynamic stabilities of these black holes according to the entropy and the effective temperature.

  7. Third molar maturity index (I3M) for assessing age of majority: study of a black South African sample.

    Science.gov (United States)

    Angelakopoulos, N; De Luca, S; Velandia Palacio, L A; Coccia, E; Ferrante, L; Cameriere, R

    2018-03-08

    The evaluation of the cutoff value of I 3M  = 0.08 for discriminating black South African minors from adults, and its relationship with chronological age. A sample of 833 panoramic radiographs of healthy black South African subjects (500 females and 333 males), in the age range of 14 to 24 years (mean age 17.67 years in females and 17.42 years in males), was retrospectively evaluated. ICC values were 99.10% (95% CI 97.70 to 99.70%) and 99.20% (95% CI 98.00 to 99.60%), for the intra- and inter-observer reliability, respectively. I 3M decreased as the real age gradually increased in both sexes. According to the logistic regression model, the variable sex was not significant when the probability that an individual is 18 years or older was calculated. The I 3M  = 0.08 was valuable in discriminating between adults and minors. The overall accuracy (ACC = fraction of accurately classified subjects) is 0.90 (95% CI 0.87-0.91); the proportion of correctly classified subjects (Se = sensitivity) is 0.80 (95% CI 0.76-0.84), and specificity (Sp) is 0.95 (95% CI 0.93-0.97). The PPV (predictive positive value) is 0.96 (95% CI 0.95-0.97), and the negative predictive value is 0.76 (95% CI 0.72-0.80). The results show that I 3M is a valuable method to distinguish subjects who are around legal adult age in South Africa.

  8. Black-Hole Mass Measurements

    DEFF Research Database (Denmark)

    Vestergaard, Marianne

    2004-01-01

    The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized.......The applicability and apparent uncertainties of the techniques currently available for measuring or estimating black-hole masses in AGNs are briefly summarized....

  9. Electromagnetic ``black holes'' in hyperbolic metamaterials

    Science.gov (United States)

    Smolyaninov, Igor

    2013-03-01

    We demonstrate that spatial variations of the dielectric tensor components in a hyperbolic metamaterial may lead to formation of electromagnetic ``black holes'' inside this metamaterial. Similar to real black holes, horizon area of the electromagnetic ``black holes'' is quantized in units of the effective ``Planck scale'' squared. Potential experimental realizations of such electromagnetic ``black holes'' will be considered. For example, this situation may be realized in a hyperbolic metamaterial in which the dielectric component exhibits critical opalescence.

  10. Rising Tide II: Do Black Students Benefit as Grad Rates Increase?

    Science.gov (United States)

    Nichols, Andrew Howard; Eberle-Sudré, Kimberlee; Welch, Meredith

    2016-01-01

    "Rising Tide II: Do Black Students Benefit as Grad Rates Increase?" looks at a decade of graduation rates for African American students at four-year, public institutions that improved student success during the past decade. It shows that while a majority (almost 70 percent) of institutions we examined improved graduation rates for black…

  11. Black Students' Recollections of Pathways to Resilience: Lessons for School Psychologists

    Science.gov (United States)

    Theron, Linda C.

    2013-01-01

    Drawing on narrative data from a multiple case study, I recount the life stories of two resilient Black South African university students to theorize about the processes that encouraged these students, familiar with penury and parental illiteracy, to resile. I aimed to uncover lessons for school psychologists about resilience, and their role in…

  12. Black European voices: The ambivalent reception of Jacobus Eliza Capitein (1717-1747)

    NARCIS (Netherlands)

    Hondius, D.G.

    2010-01-01

    In the early modern period, black European lives were and remained highly visible and exceptional. This article focuses on the experiences and reception of Jacobus Capitein and two other African men who came to Europe as children in the eighteenth century. Jacobus Capitein was enslaved when he

  13. Then and Now: Black Boycott in Waterloo.

    Science.gov (United States)

    Anderson, Ruth B.

    1983-01-01

    Discusses events following the desegregation of Waterloo, Iowa, schools. Describes the 1978 Black boycott of Hoover Junior High, which led to improvements in the treatment of Black students. Lists administrative responses to each Black grievance, and presents interviews with ten Black students three years after the boycott. (KH)

  14. Black holes: a slanted overview

    International Nuclear Information System (INIS)

    Vishveshwara, C.V.

    1988-01-01

    The black hole saga spanning some seventy years may be broadly divided into four phases, namely, (a) the dark ages when little was known about black holes even though they had come into existence quite early through the Schwarzschild solution, (b) the age of enlightenment bringing in deep and prolific discoveries, (c) the age of fantasy that cast black holes in all sorts of extraordinary roles, and (d) the golden age of relativistic astrophysics - to some extent similar to Dirac's characterisation of the development of quantum theory - in which black holes have been extensively used to elucidate a number of astrophysical phenomena. It is impossible to give here even the briefest outline of the major developments in this vast area. We shall only attempt to present a few aspects of black hole physics which have been actively pursued in the recent past. Some details are given in the case of those topics that have not found their way into text books or review articles. (author)

  15. Black hole accretion: the quasar powerhouse

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    A program is described which calculates the effects of material falling into the curved space-time surrounding a rotation black hole. The authors have developed a two-dimensional, general-relativistic hydrodynamics code to simulate fluid flow in the gravitational field of a rotating black hole. Such calculations represent models that have been proposed for the energy sources of both quasars and jets from radiogalaxies. In each case, the black hole that powers the quasar or jet would have a mass of about 100 million times the mass of the sun. The black hole would be located in the center of a galaxy whose total mass is 1000 time greater than the black hole mass. (SC)

  16. Black hole thermodynamics with conical defects

    Energy Technology Data Exchange (ETDEWEB)

    Appels, Michael [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Gregory, Ruth [Centre for Particle Theory, Durham University,South Road, Durham, DH1 3LE (United Kingdom); Perimeter Institute,31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada); Kubiznák, David [Perimeter Institute,31 Caroline Street North, Waterloo, ON, N2L 2Y5 (Canada)

    2017-05-22

    Recently we have shown https://www.doi.org/10.1103/PhysRevLett.117.131303 how to formulate a thermodynamic first law for a single (charged) accelerated black hole in AdS space by fixing the conical deficit angles present in the spacetime. Here we show how to generalise this result, formulating thermodynamics for black holes with varying conical deficits. We derive a new potential for the varying tension defects: the thermodynamic length, both for accelerating and static black holes. We discuss possible physical processes in which the tension of a string ending on a black hole might vary, and also map out the thermodynamic phase space of accelerating black holes and explore their critical phenomena.

  17. DAR, a new RhD variant involving exons 4, 5, and 7, often in linkage with ceAR, a new Rhce variant frequently found in African blacks

    NARCIS (Netherlands)

    Hemker, M. B.; Ligthart, P. C.; Berger, L.; van Rhenen, D. J.; van der Schoot, C. E.; Wijk, P. A.

    1999-01-01

    The highly polymorphic Rh system is encoded by 2 homologous genes RHD and RHCE. Gene rearrangements, deletions, or point mutations may cause partial D and CE antigens. In this study, a new RHD variant, DAR, and a new RHCE variant, ceAR, are described in 4 Dutch African Blacks. Serologically, DAR

  18. Time dependent black holes and scalar hair

    International Nuclear Information System (INIS)

    Chadburn, Sarah; Gregory, Ruth

    2014-01-01

    We show how to correctly account for scalar accretion onto black holes in scalar field models of dark energy by a consistent expansion in terms of a slow roll parameter. At leading order, we find an analytic solution for the scalar field within our Hubble volume, which is regular on both black hole and cosmological event horizons, and compute the back reaction of the scalar on the black hole, calculating the resulting expansion of the black hole. Our results are independent of the relative size of black hole and cosmological event horizons. We comment on the implications for more general black hole accretion, and the no hair theorems. (paper)

  19. How bees distinguish black from white

    Directory of Open Access Journals (Sweden)

    Horridge A

    2014-10-01

    Full Text Available Adrian Horridge Biological Sciences, Australian National University, Canberra, ACT, AustraliaAbstract: Bee eyes have photoreceptors for ultraviolet, green, and blue wavelengths that are excited by reflected white but not by black. With ultraviolet reflections excluded by the apparatus, bees can learn to distinguish between black, gray, and white, but theories of color vision are clearly of no help in explaining how they succeed. Human vision sidesteps the issue by constructing black and white in the brain. Bees have quite different and accessible mechanisms. As revealed by extensive tests of trained bees, bees learned two strong signals displayed on either target. The first input was the position and a measure of the green receptor modulation at the vertical edges of a black area, which included a measure of the angular width between the edges of black. They also learned the average position and total amount of blue reflected from white areas. These two inputs were sufficient to help decide which of two targets held the reward of sugar solution, but the bees cared nothing for the black or white as colors, or the direction of contrast at black/white edges. These findings provide a small step toward understanding, modeling, and implementing in silicon the anti-intuitive visual system of the honeybee, in feeding behavior. Keywords: vision, detectors, black/white, color, visual processing

  20. Ethnicity modifies the additive effects of anxiety and drug use disorders on suicidal ideation among black adults in the United States

    Directory of Open Access Journals (Sweden)

    Shervin Assari

    2013-01-01

    Full Text Available Background: This study aimed to test if ethnicity moderates the additive effects of lifetime psychiatric disorders on serious suicidal thoughts among a nationally representative sample of Black adults in the United States. Methods: For this study, we used data of 5,181 Black adults (3,570 African Americans and 1,621 Caribbean Blacks who participated in the National Survey of American Life, 2001-2003. Five lifetime psychiatric disorders (i.e., major depressive disorder, general anxiety disorder, post-traumatic stress disorder, alcohol abuse disorder, and drug abuse were considered as the independent variables. Lifetime serious suicidal ideation was considered as the dependent variable. Logistic regressions were used to determine if ethnicity modifies the effects of each psychiatric disorder on serious suicide ideation. Ethnicity was conceptualized as the possible moderator and socio-demographics (i.e., age, gender, education level, employment, marital status and country region were control variables. Results: Among African Americans, major depressive disorder, general anxiety disorder, post-traumatic stress disorder and alcohol abuse disorder were associated with higher odds of suicidal thoughts. Among Caribbean Blacks, major depressive disorder and drug abuse disorder were associated with higher odds of suicidal thoughts. In the pooled sample, there was a significant interaction between ethnicity and anxiety disorder and a marginally significant interaction between ethnicity and drug abuse. Conclusions: Based on our study, suicidality due to psychiatric disorders among Black adults in the United States may depend on ethnicity. General anxiety disorder seems to be a more important risk factor for suicidal ideation among African Americans while drug abuse may contribute more to the risk of suicidal thoughts among Caribbean Blacks.