Sample records for black achievement gap

  1. The Black-White achievement gap: Do state policies matter?

    Directory of Open Access Journals (Sweden)

    Henry I. Braun


    Full Text Available A longstanding issue in American education is the gap in academic achievement between majority and minority students. The goal of this study is to accumulate and evaluate evidence on the relationship between state education policies and changes in the Black-White achievement gap, while addressing some of the methodological issues that have led to differences in interpretations of earlier findings. To that end, we consider the experiences of ten states that together enroll more than forty percent of the nation's Black students. We estimate the trajectories of Black student and White student achievement on the NAEP 8th grade mathematics assessment over the period 1992 to 2000, and examine the achievement gap at three levels of aggregation: the state as a whole, groups of schools (strata within a state defined by the SES level of the student population, and within schools within a stratum within a state. From 1992 to 2000, at every level of aggregation, mean achievement rose for both Black students and White students. However, for most states the achievement gaps were large and changed very little at every level of aggregation. The gaps are pervasive, profound and persistent. There is substantial heterogeneity among states in the types of policies they pursued, as well as the coherence and consistency of those policies during the period 1988-1998. We find that states' overall policy rankings (based on our review of the data correlate moderately with their record in improving Black student achievement but are somewhat less useful in predicting their record with respect to reducing the achievement gaps. States' rankings on commitment to teacher quality correlate almost as well as did the overall policy ranking. Thus, state reform efforts are a blunt tool, but a tool nonetheless. Our findings are consistent with the following recommendations: states' reform efforts should be built on broad-based support and buffered as much as possible from changes in

  2. Another Look at the Achievement Gap: Learning from the Experiences of Gifted Black Students (United States)

    Ford, Donna Y.; Grantham, Tarek C.; Whiting, Gilman W.


    Many studies have been conducted on the achievement gap, with most findings pointing to how school and family variables affect Black students' achievement. Another body of work focuses on how social variables (i.e., peers) impact Black students' achievement, including how accusations of "acting White" affect the performance of Black students and…

  3. The Dialectical Problematic of Resolving the Black-White Academic Achievement Gap and Climate Change (United States)

    Mocombe, Paul C.


    In this article, I argue that resolving the Black-White academic achievement gap is incompatible with the emerging issues of global climate change. That is, solutions (equitable funding of schools and resources, school integration movements, and after-school and mentoring programs) for closing the gap in order so that Blacks in America and…

  4. Cultivating the Genius of Black Children: Strategies to Close the Achievement Gap in the Early Years (United States)

    Sullivan, Debra Ren-Etta


    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…

  5. Postindustrial Capitalism and the Problems with Bourdieu's Social and Cultural Capital in Understanding the Black/White Achievement Gap in the United States and United Kingdom (United States)

    Mocombe, Paul C.


    This hermeneutical essay demonstrates why and how Pierre Bourdieu's social reproduction theory is neither an adequate explanation for understanding praxis nor the Black/White academic achievement gap in contemporary postindustrial economies like that of the United States and the United Kingdom. The underlining hypothesis of the work is that the…

  6. Standing in the Gaps: Examining the Effects of Early Gifted Education on Black Girl Achievement in STEM (United States)

    Young, Jemimah L.; Young, Jamaal R.; Ford, Donna Y.


    The purpose of this study was to explore the differential effects of access to gifted education on the mathematics and science achievement of fourth-grade Black girls. This study utilized mean difference effect sizes to examine the magnitude of differences between groups. By convention, White girls were included as a comparison group. Girls…

  7. School Segregation and Racial Academic Achievement Gaps

    Directory of Open Access Journals (Sweden)

    Sean F. Reardon


    Full Text Available Although it is clear that racial segregation is linked to academic achievement gaps, the mechanisms underlying this link have been debated since James Coleman published his eponymous 1966 report. In this paper, I examine sixteen distinct measures of segregation to determine which is most strongly associated with academic achievement gaps. I find clear evidence that one aspect of segregation in particular—the disparity in average school poverty rates between white and black students’ schools—is consistently the single most powerful correlate of achievement gaps, a pattern that holds in both bivariate and multivariate analyses. This implies that high-poverty schools are, on average, much less effective than lower-poverty schools and suggests that strategies that reduce the differential exposure of black, Hispanic, and white students to poor schoolmates may lead to meaningful reductions in academic achievement gaps.

  8. School Size, Achievement, and Achievement Gaps

    Directory of Open Access Journals (Sweden)

    Bradley J. McMillen


    Full Text Available In order to examine the relationship between school size and achievement, a study was conducted using longitudinal achievement data from North Carolina for three separate cohorts of public school students (one elementary, one middle and one high school. Results revealed several interactions between size and student characteristics, all of which indicated that the achievement gaps typically existing between certain subgroups (i.e., more versus less-advantaged, lower versus higher-achieving were larger in larger schools. Results varied across the grade level cohorts and across subjects, but in general effects were more common in mathematics than in reading, and were more pronounced at the high school level. Study results are discussed in the context of educational equity and cost-effectiveness.

  9. The Black-White-Other Test Score Gap: Academic Achievement among Mixed Race Adolescents. Institute for Policy Research Working Paper. (United States)

    Herman, Melissa R.

    This paper describes the achievement patterns of a sample of 1,492 multiracial high school students and examines how their achievement fits into existing theoretical models that explain monoracial differences in achievement. These theoretical models include status attainment, parenting style, oppositional culture, and educational attitudes. The…

  10. School accountability and the black-white test score gap. (United States)

    Gaddis, S Michael; Lauen, Douglas Lee


    Since at least the 1960s, researchers have closely examined the respective roles of families, neighborhoods, and schools in producing the black-white achievement gap. Although many researchers minimize the ability of schools to eliminate achievement gaps, the No Child Left Behind Act (NCLB) increased pressure on schools to do so by 2014. In this study, we examine the effects of NCLB's subgroup-specific accountability pressure on changes in black-white math and reading test score gaps using a school-level panel dataset on all North Carolina public elementary and middle schools between 2001 and 2009. Using difference-in-difference models with school fixed effects, we find that accountability pressure reduces black-white achievement gaps by raising mean black achievement without harming mean white achievement. We find no differential effects of accountability pressure based on the racial composition of schools, but schools with more affluent populations are the most successful at reducing the black-white math achievement gap. Thus, our findings suggest that school-based interventions have the potential to close test score gaps, but differences in school composition and resources play a significant role in the ability of schools to reduce racial inequality. Copyright © 2013 Elsevier Inc. All rights reserved.

  11. Structure of Black Male Students Academic Achievement in Science (United States)

    Rascoe, Barbara

    Educational policies and practices have been largely unsuccessful in closing the achievement gap between Black and White students "Schwartz, 2001". This achievement gap is especially problematic for Black students in science "Maton, Hrabrowski, - Schmitt, 2000. Given the fact that the Black-White achievement gap is still an enigma, the purpose of this article is to address the Black female-Black male academic achievement gap in science majors. Addressing barriers that Black male students may experience as college science and engineering majors, this article presents marketing strategies relative to politics, emotional intelligence, and issues with respect to how science teaching, and Black male students' responses to it, are different. Many Black male students may need to experience a paradigm shift, which structures and enhances their science achievement. Paradigm shifts are necessary because exceptional academic ability and motivation are not enough to get Black males from their first year in a science, technology, education, and mathematics "STEM" major to a bachelor's degree in science and engineering. The conclusions focus on the balance of truth-slippery slopes concerning the confluence of science teachers' further ado and Black male students' theories, methods, and values that position their academic achievement in science and engineering majors.

  12. The Politics of Achievement Gaps

    DEFF Research Database (Denmark)

    Valant, J.; Newark, D. A.


    For decades, researchers have documented large differences in average test scores between minority and White students and between poor and wealthy students. These gaps are a focal point of reformers’ and policymakers’ efforts to address educational inequities. However, the U.S. public’s views...

  13. Subgroup Achievement and Gap Trends: Delaware (United States)

    Center on Education Policy, 2010


    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Delaware students showed consistent gains in math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. There were mixed results in reading. Achievement gaps narrowed in both reading and math in…

  14. Subgroup Achievement and Gap Trends: Massachusetts, 2010 (United States)

    Center on Education Policy, 2010


    This paper profiles the student subgroup achievement and gap trends in Massachusetts for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Massachusetts showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low…

  15. Subgroup Achievement and Gap Trends: Illinois (United States)

    Center on Education Policy, 2010


    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Illinois students showed mostly gains in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. There was mixed progress made in narrowing achievement gaps in reading and math…

  16. Subgroup Achievement and Gap Trends: Kentucky, 2010 (United States)

    Center on Education Policy, 2010


    This paper profiles the student subgroup achievement and gap trends in Kentucky for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Kentucky showed mostly gains in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls.…

  17. Subgroup Achievement and Gap Trends: Florida (United States)

    Center on Education Policy, 2010


    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Florida students showed gains almost across the board in both reading and math at the basic, proficient, and advanced levels for racial/ethnic subgroups, low income students, and boys and girls. Progress has been made in narrowing achievement gaps in both…

  18. Subgroup Achievement and Gap Trends: Nevada, 2010 (United States)

    Center on Education Policy, 2010


    This paper profiles the student subgroup achievement and gap trends in Nevada for 2010. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Nevada showed across-the-board gains--improvements in both reading and math at the basic, proficient and advanced levels for all racial/ethnic subgroups, low income…

  19. Subgroup Achievement and Gap Trends: Hawaii (United States)

    Center on Education Policy, 2010


    Hawaii showed improvement in reading and math in grade 8 at the basic, proficient, and advanced levels for Asian and white students, low income students, and boys and girls. Gains in math tended to be larger than in reading. Trends in closing achievement gaps were mixed. Comparable data were available from 2007 through 2009. (Contains 9 tables.)…

  20. Decomposing Achievement Gaps among OECD Countries (United States)

    Zhang, Liang; Lee, Kristen A.


    In this study, we use decomposition methods on PISA 2006 data to compare student academic performance across OECD countries. We first establish an empirical model to explain the variation in academic performance across individuals, and then use the Oaxaca-Blinder decomposition method to decompose the achievement gap between each of the OECD…

  1. The Black-White Achievement Gap Revisited Revisitando la brecha en el rendimiento de estudiantes negros y blancos Revisitando a defasagem de rendimento academico dos estudantes negros e brancos

    Directory of Open Access Journals (Sweden)

    Henry Braun


    Full Text Available This study examines trends in Black student achievement and in the Black-White achievement gap over the period 2000 to 2007, employing data from ten states drawn from the NAEP Grade 8 mathematics assessments. Results are obtained for three levels of aggregation: the state, school poverty stratum within the state, and schools within poverty stratum. In addition, information on the ten states’ education policies for the period 1998 to 2005 was compiled. States relative ranks on the overall strength of their reform efforts were compared to their relative ranks with respect to their success in improving Black student achievement and in reducing the Black- White achievement gap. This study constitutes an extension of earlier work that considered the same issues for the period 1992 to 2000 and, thus, offers a unique comparison between the pre-NCLB era and the present one. Although the ten states certainly differed in their outcomes, the general picture at all three levels of aggregation is quite clear: The achievement gaps are substantial and the introduction of federally mandated high stakes test-based accountability through No Child Left Behind has had a very modest impact on the rates of improvement for Black students and on the pace of reductions in the achievement gaps between Black students and White students. Moreover, there was only a weak association between states’ policy rankings and their rankings related to test results. It appears there is a need for both fresh thinking on education reform and a more concerted effort to collect comprehensive longitudinal information on states' education policies.
    Este estudio examina las tendencias en el rendimiento académico de estudiantes negros y la brecha en el rendimiento de los estudiantes negros y blancos en el período 2000 a 2007, utilizando datos de las evaluaciones NAEP de Matemáticas para el octavo grado en diez estados. Se obtuvieron resultados para tres niveles de agregacio

  2. Divergent Streams: Race-Gender Achievement Gaps at Selective Colleges and Universities


    Massey, Douglas S.; Probasco, LiErin


    In this paper, we extend previous research on racial performance gaps at 28 selective US colleges and universities by examining differences in grade achievement and graduate rates across race-gender categories. Using data from the National Longitudinal Survey of Freshmen, we show that black males, black females, and Hispanic males attain significantly lower grades than other race-gender groups, and that black males are 35% less likely to graduate on-time than other race-gender groups. Analyse...

  3. Causes of and Solutions to the Achievement Gap: Teachers' Perceptions (United States)

    Ratcliff, Nancy J.; Costner, Richard H.; Carroll, Kimberly L.; Jones, Cathy R.; Sheehan, Heather Chase; Hunt, Gilbert H.


    Survey results from 874 educators regarding the achievement gap are shared. The importance of the achievement gap, causes of and solutions to the achievement gap, and performance expectations for students in their schools are explored. Implications for teacher educators are discussed as related to both pre-service and in-service training programs.

  4. "Brown" and Black-White Achievement (United States)

    Armor, David J.


    "Brown v. Board of Education" only presumed to eliminate the "de jure" apartheid that existed in 1954. It was never intended to resolve the "de facto" gap in minority achievement that still faces education policymakers today. Sociologist David J. Armor goes beyond "Brown" to identify a set of definite risk…

  5. Counterstereotypic Identity among High-Achieving Black Students (United States)

    Harpalani, Vinay


    This article examines how racial stereotypes affect achievement and identity formation among low income, urban Black adolescents. Specifically, the major question addressed is: how do high-achieving Black students succeed academically despite negative stereotypes of their intellectual abilities? Results indicate that high-achieving Black youth,…

  6. Subgroup Achievement and Gap Trends: Maine (United States)

    Center on Education Policy, 2010


    In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Maine students had across-the-board gains. There were improvements in both reading and math at the basic, proficient and advanced levels for the subgroups large enough to count, which were white students, low income students, and boys and girls. Results on…

  7. Educational Achievement and Black-White Inequality. Statistical Analysis Report. (United States)

    Jacobson, Jonathan; Olsen, Cara; Rice, Jennifer King; Sweetland, Stephen

    This study explored relationships between black-white differences in educational achievement and black-white differences in various educational and economic outcomes. Three data sets examined the extent to which black-white differences in labor market outcomes, in educational attainment, and in mathematics and reading achievement were present for…

  8. From Crisis Management to Academic Achievement: A University Cluster-Mentoring Model for Black Undergraduates (United States)

    Apprey, Maurice; Preston-Grimes, Patrice; Bassett, Kimberley C.; Lewis, Dion W.; Rideau, Ryan M.


    In spite of the widening racial achievement gap among U.S. college students (U.S. Census Bureau, 2011), some universities are achieving success in supporting the graduation and postcollege goals of Black undergraduates (Apprey, Bassett, Preston-Grimes, Lewis, & Wood 2014/this issue; Baker, 2006; Hrabowski, 2003; Hrabowski & Maton, 2009).…

  9. Expanding METCO and Closing Achievement Gaps. White Paper No. 129 (United States)

    Apfelbaum, Katherine; Ardon, Ken


    School systems around the United States are heavily segregated by income and race. At the same time, an achievement gap between white and nonwhite students persists despite many efforts to close it. Against this background, in this white paper the authors explore the history and successes of the Metropolitan Council for Educational Opportunity…

  10. Gap in the black-body spectrum at low temperature

    International Nuclear Information System (INIS)

    Schwarz, Markus; Hofmann, Ralf; Giacosa, Francesco


    We postulate that the U(1) Y factor of the Standard Model is an effective manifestation of SU(2) gauge dynamics being dynamically broken by nonperturbative effects. The modified propagation properties of the photon at low temperatures and momenta are computed. As a result of strong screening, the presence of a sizable gap in the spectral power of a black body at temperatures T = 5...20 K and for low frequencies is predicted: A table-top experiment should be able to discover this gap. If the gap is observed then the Standard Model's mechanism for electroweak symmetry-breaking is endangered by a contradiction with Big-Bang nucleosynthesis. Based on our results, we propose an explanation for the stability of cold, old, dilute, and large clouds of atomic hydrogen in between spiral arms of the outer galaxy

  11. Spatial distribution and size of small canopy gaps created by Japanese black bears: estimating gap size using dropped branch measurements. (United States)

    Takahashi, Kazuaki; Takahashi, Kaori


    Japanese black bears, a large-bodied omnivore, frequently create small gaps in the tree crown during fruit foraging. However, there are no previous reports of black bear-created canopy gaps. To characterize physical canopy disturbance by black bears, we examined a number of parameters, including the species of trees in which canopy gaps were created, gap size, the horizontal and vertical distribution of gaps, and the size of branches broken to create gaps. The size of black bear-created canopy gaps was estimated using data from branches that had been broken and dropped on the ground. The disturbance regime was characterized by a highly biased distribution of small canopy gaps on ridges, a large total overall gap area, a wide range in gap height relative to canopy height, and diversity in gap size. Surprisingly, the annual rate of bear-created canopy gap formation reached 141.3 m2 ha-1 yr-1 on ridges, which were hot spots in terms of black bear activity. This rate was approximately 6.6 times that of tree-fall gap formation on ridges at this study site. Furthermore, this rate was approximately two to three times that of common tree-fall gap formation in Japanese forests, as reported in other studies. Our findings suggest that the ecological interaction between black bears and fruit-bearing trees may create a unique light regime, distinct from that created by tree falls, which increases the availability of light resources to plants below the canopy.

  12. Science Achievement Gaps by Gender and Race/Ethnicity in Elementary and Middle School: Trends and Predictors (United States)

    Quinn, David M.; Cooc, North


    Research on science achievement disparities by gender and race/ethnicity often neglects the beginning of the pipeline in the early grades. We address this limitation using nationally representative data following students from Grades 3 to 8. We find that the Black-White science test score gap (-1.07 SD in Grade 3) remains stable over these years,…

  13. The theory-practice gap of black carbon mitigation technologies in rural China (United States)

    Zhang, Weishi; Li, Aitong; Xu, Yuan; Liu, Junfeng


    Black carbon mitigation has received increasing attention for its potential contribution to both climate change mitigation and air pollution control. Although different bottom-up models concerned with unit mitigation costs of various technologies allow the assessment of alternative policies for optimized cost-effectiveness, the lack of adequate data often forced many reluctant explicit and implicit assumptions that deviate away from actual situations of rural residential energy consumption in developing countries, where most black carbon emissions occur. To gauge the theory-practice gap in black carbon mitigation - the unit cost differences that lie between what is estimated in the theory and what is practically achieved on the ground - this study conducted an extensive field survey and analysis of nine mitigation technologies in rural China, covering both northern and southern regions with different residential energy consumption patterns. With a special focus on two temporal characteristics of those technologies - lifetimes and annual utilization rates, this study quantitatively measured the unit cost gaps and explain the technical as well as sociopolitical mechanisms behind. Structural and behavioral barriers, which have affected the technologies' performance, are discussed together with policy implications to narrow those gaps.

  14. Black hole elasticity and gapped transverse phonons in holography (United States)

    Alberte, Lasma; Ammon, Martin; Baggioli, Matteo; Jiménez, Amadeo; Pujolàs, Oriol


    We study the elastic response of planar black hole (BH) solutions in a simple class of holographic models with broken translational invariance. We compute the transverse quasi-normal mode spectrum and the propagation speed of the lowest energy mode. We find that the speed of the lowest mode relates to the BH rigidity modulus as dictated by elasticity theory. This allows to identify these modes as transverse phonons — the pseudo Goldstone bosons of spontaneously broken translational invariance. In addition, we show that these modes have a mass gap controlled by an explicit source of the translational symmetry breaking. These results provide a new confirmation that the BHs in these models do exhibit solid properties that become more manifest at low temperatures. Also, by the AdS/CFT correspondence, this allows to extend the standard results from the effective field theory for solids to quantum-critical materials.

  15. Divergent Streams: Race-Gender Achievement Gaps at Selective Colleges and Universities. (United States)

    Massey, Douglas S; Probasco, Lierin


    In this paper, we extend previous research on racial performance gaps at 28 selective US colleges and universities by examining differences in grade achievement and graduate rates across race-gender categories. Using data from the National Longitudinal Survey of Freshmen, we show that black males, black females, and Hispanic males attain significantly lower grades than other race-gender groups, and that black males are 35% less likely to graduate on-time than other race-gender groups. Analyses consider an array of personal and institutional indicators of academic performance. Grades and graduation rates are improved by academic preparation (particularly high school GPA), scholarly effort, and, for graduation rates, membership in career-oriented or majority-white campus groups. Grade performance and graduation rates are undermined by a hostile racial climate on campus, family stress, and stereotype threat, all of which disproportionately affect minority students. We conclude with recommendations to college administrators for ways of selecting and supporting minority students to reduce differentials in academic achievement across race-gender groups.

  16. Linking Communalism to Achievement Correlates for Black and White Undergraduates (United States)

    Tyler, Kenneth; Love, Keisha; Brown, Carrie; Roan-Belle, Clarissa; Thomas, Deneia; Garriott, Patton O.


    This study examined relationships between home-based communal activities and beliefs and student reports of various achievement correlates with 290 black and white undergraduates. MANOVA procedures examined differences in self-esteem, self-efficacy, identified motivation, motivation to know, and amotivation and scores on Home Communalism Measure…

  17. Physical activity and the achievement gap among urban minority youth. (United States)

    Basch, Charles E


    To outline the prevalence and disparities of physical activity among school-aged urban minority youth, causal pathways through which low levels of physical activity and fitness adversely affects academic achievement, and proven or promising approaches for schools to increase physical activity and physical fitness among youth. Literature review. A large proportion of youth is insufficiently physically active. Estimates of population-wide levels of physical activity indicate that Black and Hispanic youth are less physically active than White youth, with disparities particularly evident for females. The population segments of youth with lowest levels of physical activity and fitness also have least access to school-based physical activity opportunities and resources. Physical activity affects metabolism and all major body systems, exerting powerful positive influences on the brain and spinal cord and, consequently, on emotional stability, physical health, and motivation and ability to learn. The cornerstone of school-based physical activity programs should be a high-quality physical education program based on national standards. Such programs are strongly recommended by the Task Force on Community Preventive Services as a way to increase physical activity and physical fitness among youth. Physical inactivity is highly and disproportionately prevalent among school-aged urban minority youth, has a negative impact on academic achievement through its effects on cognition, and effective practices are available for schools to address this problem. Increasing students' physical activity and physical fitness can best be achieved through a comprehensive approach that includes physical education, wise use of recess and after-school times, co-curricular physical activity opportunities, and bicycling or walking to and from school. © 2011, American School Health Association.

  18. The Measured Black-White Wage Gap among Women Is Too Small. (United States)

    Neal, Derek


    Existing work suggests that black-white gaps in potential wages are much larger among men than women and further that black-white differences in patterns of female labor supply are unimportant. However, panel data on wages and income sources demonstrate that the modal young black woman who does not engage in market work is a single mother…

  19. Patterns of Change in U.S. Gender Achievement Gaps during Elementary and Middle School (United States)

    Fahle, Erin


    Research on gender achievement gaps shows they exist, and are largest in the tails of the distribution, starting as early as Kindergarten and persisting through eighth grade. In mathematics, studies find small average gender achievement gaps and larger systematically male-favoring gaps among the highest achieving students. This paper seeks to…

  20. Breakfast and the achievement gap among urban minority youth. (United States)

    Basch, Charles E


    To outline the prevalence and disparities of breakfast consumption among school-aged urban minority youth, causal pathways through which skipping breakfast adversely affects academic achievement, and proven or promising approaches for schools to increase breakfast consumption. Literature review. On any given day a substantial proportion of American youth do not eat breakfast. On an average day, less than half (∼46%) of children participating in free or reduced-price lunch also participated in the School Breakfast Program for which they were also eligible. In a large study of 9-year-olds, 77% of White girls and 57% of Black girls consumed breakfast on all 3 days assessed; by age 19, the respective rates were 32% and 22%. Neuroscience research has identified the processes by which dietary behavior influences neuronal activity and synaptic plasticity, both of which influence cognitive functions. Participation in School Breakfast Programs has also been associated with reduced absenteeism. Universal School Breakfast Programs and allowing youth to eat breakfast in the classroom (vs cafeteria) are approaches that have been shown to increase participation. Skipping breakfast is highly and disproportionately prevalent among school-aged urban minority youth, has a negative impact on academic achievement by adversely affecting cognition and absenteeism, and effective practices are available for schools to address this problem. Despite wide availability, the majority of American youth do not participate in School Breakfast Programs. High-quality universal breakfast programs that allow students to eat breakfast in the classroom are especially needed for youth who are not likely to get good nutrition the rest of the day. © 2011, American School Health Association.

  1. Explaining the Female Black-White Obesity Gap: A Decomposition Analysis of Proximal Causes


    Johnston, David W.; Lee, Wang-Sheng


    There exists remarkably large differences in body weights and obesity prevalence between black and white women in the US, and crucially these differences are a significant contributor to black-white inequalities in health. In this paper, we investigate the most proximal explanations for the weight gap, namely differences in diet and exercise. More specifically, we decompose black-white differences in body mass index and waist-to-height ratio into components reflecting black-white differences ...

  2. Teen pregnancy and the achievement gap among urban minority youth. (United States)

    Basch, Charles E


    To outline the prevalence and disparities of teen pregnancy among school-aged urban minority youth, causal pathways through which nonmarital teen births adversely affects academic achievement, and proven or promising approaches for schools to address this problem. Literature review. In 2006, the birth rate among 15- to 17-year-old non-Hispanic Blacks (36.1 per 1000) was more than three times as high, and the birth rate among Hispanics (47.9 per 1000) was more than four times as high as the birth rate among non-Hispanic Whites (11.8 per 1000). Compared with women who delay childbearing until age 30, teen mothers' education is estimated to be approximately 2 years shorter. Teen mothers are 10-12% less likely to complete high school and have 14-29% lower odds of attending college. School-based programs have the potential to help teens acquire the knowledge and skills needed to postpone sex, practice safer sex, avoid unintended pregnancy, and if pregnant, to complete high school and pursue postsecondary education. Most students in US middle and high schools receive some kind of sex education. Federal policies and legislation have increased use of the abstinence-only-until-marriage approach, which is disappointing considering the lack of evidence that this approach is effective. Nonmarital teen births are highly and disproportionately prevalent among school-aged urban minority youth, have a negative impact on educational attainment, and effective practices are available for schools to address this problem. Teen pregnancy exerts an important influence on educational attainment among urban minority youth. Decisions about what will be taught should be informed by empirical data documenting the effectiveness of alternative approaches. © 2011, American School Health Association.

  3. Do Small Canopy Gaps Created by Japanese Black Bears Facilitate Fruiting of Fleshy-Fruited Plants?

    Directory of Open Access Journals (Sweden)

    Kazuaki Takahashi

    Full Text Available Japanese black bears often break branches when climbing trees and feeding on fruit in canopies, thereby creating small canopy gaps. However, the role of black bear-created canopy gaps has not been evaluated in the context of multiple forest dynamics. Our hypothesis was that small canopy gaps created by black bears improve light conditions, which facilitates fruiting of adult fleshy-fruited plants located beneath the gaps, and also that this chain interaction depends on interactions among the size of gaps, improved light conditions, forest layers, and life form of plants. The rPPFD, size of black bear-created canopy gaps, and fruiting/non-fruiting of fleshy-fruited plants were investigated in five forest layers beneath black-bear-created canopy gaps and closed canopies of Mongolian oak (Quercus crispula. We found that light conditions improved beneath black bear-disturbed trees with canopy gaps of large size, and the effect of improvement of light conditions was reduced with descending forest layers. Fruiting of fleshy-fruited plants, especially woody lianas and trees, was facilitated by the improvement of light conditions accompanied by an increase in the size of black-bear-created gaps. Data from this study revealed that canopy disturbance by black bears was key for improving light conditions and accelerating fruiting of fleshy-fruited trees and woody lianas in the canopy layers in particular. Therefore, our hypothesis was mostly supported. Our results provide evidence that Japanese black bears have high potential as ecosystem engineers that increase the availability of resources (light and fruit in this study to other species by causing physical state changes in biotic materials (branches of Q. crispula in this study.

  4. Do Small Canopy Gaps Created by Japanese Black Bears Facilitate Fruiting of Fleshy-Fruited Plants? (United States)

    Takahashi, Kazuaki; Takahashi, Kaori; Washitani, Izumi


    Japanese black bears often break branches when climbing trees and feeding on fruit in canopies, thereby creating small canopy gaps. However, the role of black bear-created canopy gaps has not been evaluated in the context of multiple forest dynamics. Our hypothesis was that small canopy gaps created by black bears improve light conditions, which facilitates fruiting of adult fleshy-fruited plants located beneath the gaps, and also that this chain interaction depends on interactions among the size of gaps, improved light conditions, forest layers, and life form of plants. The rPPFD, size of black bear-created canopy gaps, and fruiting/non-fruiting of fleshy-fruited plants were investigated in five forest layers beneath black-bear-created canopy gaps and closed canopies of Mongolian oak (Quercus crispula). We found that light conditions improved beneath black bear-disturbed trees with canopy gaps of large size, and the effect of improvement of light conditions was reduced with descending forest layers. Fruiting of fleshy-fruited plants, especially woody lianas and trees, was facilitated by the improvement of light conditions accompanied by an increase in the size of black-bear-created gaps. Data from this study revealed that canopy disturbance by black bears was key for improving light conditions and accelerating fruiting of fleshy-fruited trees and woody lianas in the canopy layers in particular. Therefore, our hypothesis was mostly supported. Our results provide evidence that Japanese black bears have high potential as ecosystem engineers that increase the availability of resources (light and fruit in this study) to other species by causing physical state changes in biotic materials (branches of Q. crispula in this study).

  5. Ultrawide band gaps in beams with double-leaf acoustic black hole indentations. (United States)

    Tang, Liling; Cheng, Li


    Band gaps in conventional phononic crystals (PCs) are attractive for applications such as vibration control, wave manipulation, and sound absorption. Their practical implementations, however, are hampered by several factors, among which the large number of cells required and their impractically large size to ensure the stopbands at reasonably low frequencies are on the top of the list. This paper reports a type of beam carved inside with two double-leaf acoustic black hole indentations. By incorporating the local resonance effect and the Bragg scattering effect generated by a strengthening stud connecting the two branches of the indentations, ultrawide band gaps are achieved. Increasing the length of the stud or reducing the residual thickness of the indentation allows the tuning of the band gaps to significantly enlarge the band gaps, which can exceed 90% of the entire frequency range of interest. Experimental results show that with only three cells, the proposed beam allows considerable vibration energy attenuation within an ultra-broad frequency range including the low frequency range, which conventional PCs can hardly reach. Meanwhile, the proposed configuration also enhances the structural integrity, thus pointing at promising applications in vibration control and a high performance wave filter design.

  6. Test Format and the Variation of Gender Achievement Gaps within the United States (United States)

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia


    Prior research demonstrates the existence of gender achievement gaps and the variation in the magnitude of these gaps across states. This paper characterizes the extent to which the variation of gender achievement gaps on standardized tests across the United States can be explained by differing state accountability test formats. A comprehensive…

  7. Will Public Pre-K Really Close Achievement Gaps? Gaps in Prekindergarten Quality between Students and across States (United States)

    Valentino, Rachel


    Publicly funded pre-K is often touted as a means to narrow achievement gaps, but this goal is less likely to be achieved if poor and/or minority children do not, at a minimum, attend equal quality pre-K as their non-poor, non-minority peers. In this paper, I find large "quality gaps" in public pre-K between poor, minority students and…

  8. Evaluating the Effects of Programs for Reducing Achievement Gaps: A Case Study in Taiwan (United States)

    Sung, Yao-Ting; Tseng, Fen-Lan; Kuo, Nien-Ping; Chang, Tien-Ying; Chiou, Jia-Min


    Considering that achievement gaps have become a serious educational problem worldwide, the Ministry of Education in Taiwan has been addressing a series of policies to reduce achievement gaps, but the effect of these policies has not yet been carefully examined. Therefore, the present study investigated current educational policies, achievement gap…

  9. Acknowledging the gap between aspiration and achievement in ...

    African Journals Online (AJOL)

    Almost three years have passed since the discussions which led to the ... production of this special issue took place. Those years have been challenging ones for Madagascar and the Malagasy, due to the ongoing political situation and its broader impacts on ... there is often a considerable gap between the discourse of.

  10. Subgroup Achievement and Gap Trends: District of Columbia (United States)

    Center on Education Policy, 2010


    The District's demographics are such that achievement trends could only be determined for African American, male and female, and low income subgroups. In grade 8 (the only grade in which subgroup trends were analyzed by achievement level), Washington, DC students showed gains in both reading and math at the basic, proficient, and advanced levels…

  11. School Segregation and Racial Academic Achievement Gaps. CEPA Working Paper No. 15-12 (United States)

    Reardon, Sean F.


    Although it is clear that racial segregation is linked to academic achievement gaps, the mechanisms underlying this link have been debated since Coleman published his eponymous 1966 report. In this paper, I examine 16 distinct measures of segregation to determine which is most strongly associated with academic achievement gaps. I find very clear…

  12. Are Boys Left Behind? The Evolution of the Gender Achievement Gap in Beijing's Middle Schools (United States)

    Lai, Fang


    Using one cohort of 7235 middle school students in Beijing, China, we examined the evolution of the gender achievement gap in middle school. Our study found a more significant female dominance than in U.S. studies: even though boys gradually caught up during middle school, especially in Math and Science, and the gender achievement gap decreased…

  13. Teen Pregnancy and the Achievement Gap among Urban Minority Youth (United States)

    Basch, Charles E.


    Objectives: To outline the prevalence and disparities of teen pregnancy among school-aged urban minority youth, causal pathways through which nonmarital teen births adversely affects academic achievement, and proven or promising approaches for schools to address this problem. Methods: Literature review. Results: In 2006, the birth rate among 15-…

  14. Early College High School: Closing the Latino Achievement Gap (United States)

    Beall, Kristen Ann


    The population of United States Latino students is growing at a rapid rate but their academic achievement lags behind white and Asian students. This issue has significant consequences for the nation's economy, as the job market continues to demand more education and better skills. Early College High School programs have the potential to improve…

  15. Asthma and the Achievement Gap among Urban Minority Youth (United States)

    Basch, Charles E.


    Objectives: To outline the prevalence and disparities of asthma among school-aged urban minority youth, causal pathways through which poorly controlled asthma adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Methods: Literature review. Results: Asthma is the most common chronic…

  16. Breakfast and the Achievement Gap among Urban Minority Youth (United States)

    Basch, Charles E.


    Objectives: To outline the prevalence and disparities of breakfast consumption among school-aged urban minority youth, causal pathways through which skipping breakfast adversely affects academic achievement, and proven or promising approaches for schools to increase breakfast consumption. Methods: Literature review. Results: On any given day a…

  17. The Achievement Gap between Science Classrooms and Historic Inequalities (United States)

    Howie, Sarah; Scherman, Vanessa


    In the past politics deprived many African children (in particular) in South Africa the opportunity of achieving quality education. This was most especially true in subjects such as mathematics and science. In this research the science teacher-level data from Third International Mathematics and Science Study 1999 (TIMSS'99) were analysed with a…

  18. County-level racial prejudice and the black-white gap in infant health outcomes. (United States)

    Orchard, Jacob; Price, Joseph


    Black mothers are 60 percent more likely than white mothers to have preterm births and twice as likely to have a baby with low birth weight. We examine whether these black-white gaps in birth outcomes are larger in counties with higher levels of racial prejudice. We use data from the restricted-use natality files in the United States, which provide information on birth weight, gestation, and maternal characteristics for over 31 million births from 2002 to 2012, combined with county-level data measures of both explicit and implicit racial prejudice from Project Implicit from over a million individuals who took the Implicit Association Test during this same period. We compare counties that are one standard deviation above the mean (high prejudice) with those that are one standard deviation below the mean (low prejudice) in terms of their average level of racial prejudice. The black-white gap in low birth weight is 14 percent larger in counties with high implicit racial prejudice compared to counties with low prejudice. The black-white gap in preterm births is 29 percent larger in the high prejudice counties. The gaps are even larger when we use explicit measures of racial prejudice with high prejudice counties having a black-white gap that is 22 percent larger for low birth weight and 36 percent larger for preterm births. These relationships do not appear to be biased by the way the prejudice sample is constructed, since the racial gap in birth outcomes is unrelated to other county-level biases such as those based on gender or sexual orientation. The black-white gap in United States' birth outcomes is larger in those counties that have the highest levels of racial prejudice. This is true for both implicit and explicit racial prejudice, though the strength of the relationship is strongest for explicit racial prejudice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Wide gap Chern Mott insulating phases achieved by design (United States)

    Guo, Hongli; Gangopadhyay, Shruba; Köksal, Okan; Pentcheva, Rossitza; Pickett, Warren E.


    Quantum anomalous Hall insulators, which display robust boundary charge and spin currents categorized in terms of a bulk topological invariant known as the Chern number (Thouless et al Phys. Rev. Lett. 49, 405-408 (1982)), provide the quantum Hall anomalous effect without an applied magnetic field. Chern insulators are attracting interest both as a novel electronic phase and for their novel and potentially useful boundary charge and spin currents. Honeycomb lattice systems such as we discuss here, occupied by heavy transition-metal ions, have been proposed as Chern insulators, but finding a concrete example has been challenging due to an assortment of broken symmetry phases that thwart the topological character. Building on accumulated knowledge of the behavior of the 3d series, we tune spin-orbit and interaction strength together with strain to design two Chern insulator systems with bandgaps up to 130 meV and Chern numbers C = -1 and C = 2. We find, in this class, that a trade-off between larger spin-orbit coupling and strong interactions leads to a larger gap, whereas the stronger spin-orbit coupling correlates with the larger magnitude of the Hall conductivity. Symmetry lowering in the course of structural relaxation hampers obtaining quantum anomalous Hall character, as pointed out previously; there is only mild structural symmetry breaking of the bilayer in these robust Chern phases. Recent growth of insulating, magnetic phases in closely related materials with this orientation supports the likelihood that synthesis and exploitation will follow.

  20. Closing the Racial Achievement Gap: Learning from Florida's Reforms. Backgrounder. No. 2468 (United States)

    Ladner, Matthew; Burke, Lindsey M.


    An education gap between white students and their black and Hispanic peers is something to which most Americans have become accustomed. But this racial division of education--and hence of prospects for the future--is nothing less than tragic. The good news is that the racial divide in learning is a problem that can be fixed. Of course, it can only…

  1. Geographic Variation of District-Level Gender Achievement Gaps within the United States (United States)

    Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia


    Gender achievement gaps on national and state assessments have been a popular research topic over the last few decades. Many prior studies examine these gaps in different subjects (e.g., mathematics, reading, and science) and grades (typically kindergarten through eighth grade) for students living in various regions (typically states or countries)…

  2. The Academic Achievement Gap between African American and White Students: An Exploratory Study on Reading Achievement and Intrinsic Motivation (United States)

    Herron-McCoy, La-Monica


    The purpose of this study was to explore the academic achievement gap between upper elementary African American and White students. This study sought to assess any relationships between whether academic reading, students attitudes toward reading, and academic intrinsic motivation related to ethnicity. This study also sought to assess whether…

  3. Interventions aimed at closing the social class achievement gap: changing individuals, structures, and construals. (United States)

    Dittmann, Andrea G; Stephens, Nicole M


    Understanding the sources of the social class achievement gap in education is an important step toward ensuring that education serves its purpose as an engine of social mobility. The goal of the current article is to provide a brief overview of the sources of the social class achievement gap as well as interventions aimed at closing this gap. We outline three major sources of the social class achievement gap-individual skills, structural conditions, and people's processes of meaning-making, or construals-and the interventions that target them. While all of these interventions can effect change, we propose that interventions will be most effective when tailored to fit the specific needs of students and the context in which they are delivered. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Explaining the black-white gap in cognitive test scores: Toward a theory of adverse impact. (United States)

    Cottrell, Jonathan M; Newman, Daniel A; Roisman, Glenn I


    In understanding the causes of adverse impact, a key parameter is the Black-White difference in cognitive test scores. To advance theory on why Black-White cognitive ability/knowledge test score gaps exist, and on how these gaps develop over time, the current article proposes an inductive explanatory model derived from past empirical findings. According to this theoretical model, Black-White group mean differences in cognitive test scores arise from the following racially disparate conditions: family income, maternal education, maternal verbal ability/knowledge, learning materials in the home, parenting factors (maternal sensitivity, maternal warmth and acceptance, and safe physical environment), child birth order, and child birth weight. Results from a 5-wave longitudinal growth model estimated on children in the NICHD Study of Early Child Care and Youth Development from ages 4 through 15 years show significant Black-White cognitive test score gaps throughout early development that did not grow significantly over time (i.e., significant intercept differences, but not slope differences). Importantly, the racially disparate conditions listed above can account for the relation between race and cognitive test scores. We propose a parsimonious 3-Step Model that explains how cognitive test score gaps arise, in which race relates to maternal disadvantage, which in turn relates to parenting factors, which in turn relate to cognitive test scores. This model and results offer to fill a need for theory on the etiology of the Black-White ethnic group gap in cognitive test scores, and attempt to address a missing link in the theory of adverse impact. (c) 2015 APA, all rights reserved).

  5. Understanding Science Achievement Gaps by Race/Ethnicity and Gender in Kindergarten and First Grade (United States)

    Curran, F. Chris; Kellogg, Ann T.


    Disparities in science achievement across race and gender have been well documented in secondary and postsecondary school; however, the science achievement gap in the early years of elementary school remains understudied. We present findings from the recently released Early Childhood Longitudinal Study, Kindergarten Class of 2010-2011 that…

  6. Book Review: Academic Profiling: Latinos, Asian Americans, and the Achievement Gap


    Murillo, Marco Antonio


    Addressing the “achievement gap” in academic performance has become prominent in educational reform efforts.   However, too often, outcomes gathered from accountability measures are used to create hierarchies between students’ performance based on gender and race/ethnicity.  In Academic Profiling: Latinos, Asian American, and the Achievement Gap, Gilda L. Ochoa examines how a focus on the “achievement gap,” which she argues gives the “illusion” that inequality is being addressed by shifting t...

  7. Closing the achievement gap: the association of racial climate with achievement and behavioral outcomes. (United States)

    Mattison, Erica; Aber, Mark S


    This study investigated the relationship between school racial climate and students' self-reports of academic and discipline outcomes, including whether racial climate mediated and/or moderated the relationship between race and outcomes. Using the Racial Climate Survey-High School Version (M. Aber et al., unpublished), data were gathered from African American (n = 382) and European American students (n = 1456) regarding their perceptions of racial climate. About 18% of the respondents were low-income and approximately 50% were male. Positive perceptions of the racial climate were associated with higher student achievement and fewer discipline problems. Further, race moderated the relationship between racial climate and both achievement and discipline outcomes. Finally, racial differences in students' grades and discipline outcomes were associated with differences in perceptions of racial climate. Results suggest careful attention should be given to the racial climate of secondary schools, particularly for adolescents who perceive schools as unfair.

  8. Placement Work Experience May Mitigate Lower Achievement Levels of Black and Asian vs. White Students at University (United States)

    Moores, Elisabeth; Birdi, Gurkiran K.; Higson, Helen E.


    Ethnic minority groups have been shown to obtain poorer final year degree outcomes than their majority group counterparts in countries including the United States, the United Kingdom and The Netherlands. Obtaining a lower degree classification may limit future employment prospects of graduates as well as opportunities for higher level study. To further investigate this achievement gap, we analyzed performance levels across three academic years of study of 3,051 Black, Asian and White students from a United Kingdom University. Analyses of covariance investigated effects of ethnicity and work placement experience (internships) on first, second and final year marks, whilst statistically controlling for a number of factors thought to influence achievement, including prior academic performance. Results demonstrated superior achievement of White students consistently across all years of study. Placement experience reduced, but did not eliminate, the size of the achievement gap exhibited by final year students. Sex, parental education and socioeconomic status had no significant main effects. Female students showed a more complex pattern of results than males, with Black females not showing the same final year uplift in marks as their Asian and White counterparts. Implications and possible explanations are discussed. PMID:28955263

  9. Beyond Popular Cultural and Structural Arguments: Imagining a Compass to Guide Burgeoning Urban Achievement Gap Scholars (United States)

    Hughes, Sherick A.; North, Connie E.


    This manuscript begins by distinguishing the common structural and cultural arguments that tend to guide popular urban achievement gap research. It highlights Jencks and Phillips, and Payne, as two cases of popular texts followed by critical responses to them. It concludes by imagining a compass to guide burgeoning scholars toward reading into…

  10. Understanding the Gender Gap in Mathematics Achievement: The Role of Self-Efficacy and Stereotype Threat (United States)

    Schwery, Denise; Hulac, David; Schweinle, Amy


    This literature review provides school psychologists with an understanding of the important issues related to the gender gap in mathematics achievement. The extant literature suggests that girls tend to receive lower scores than boys on standardized math tests, but in general these differences tend to be small. However, girls have better classroom…

  11. Gender Gaps in Mathematics, Science and Reading Achievements in Muslim Countries: A Quantile Regression Approach (United States)

    Shafiq, M. Najeeb


    Using quantile regression analyses, this study examines gender gaps in mathematics, science, and reading in Azerbaijan, Indonesia, Jordan, the Kyrgyz Republic, Qatar, Tunisia, and Turkey among 15-year-old students. The analyses show that girls in Azerbaijan achieve as well as boys in mathematics and science and overachieve in reading. In Jordan,…

  12. Values Affirmation Intervention Reduces Achievement Gap between Underrepresented Minority and White Students in Introductory Biology Classes (United States)

    Jordt, Hannah; Eddy, Sarah L.; Brazil, Riley; Lau, Ignatius; Mann, Chelsea; Brownell, Sara E.; King, Katherine; Freeman, Scott


    Achievement gaps between underrepresented minority (URM) students and their white peers in college science, technology, engineering, and mathematics classrooms are persistent across many white-majority institutions of higher education. Attempts to reduce this phenomenon of underperformance through increasing classroom structure via active learning…

  13. The Educational Achievement Gap as a Social Justice Issue for Teacher Educators (United States)

    Collopy, Rachel; Bowman, Connie; Taylor, David A.


    The educational achievement gap is a critical social justice issue. Catholic and Marianist conceptions of social justice in particular call people to work with others in their spheres of life to transform institutions in order to further human rights while promoting the common good. Drawing on key elements of Catholic teaching on social justice,…

  14. Bridging English Language Learner Achievement Gaps through Effective Vocabulary Development Strategies (United States)

    Gibson, Charles


    Despite a well-documented history of immigration in the United States of America and rise in population of students that speak a language other than English, academic achievement gaps between English Language Learners and their native English language speaking counterparts from Grades Pre-Kindergarten through the college/university level still…

  15. Values Affirmation Intervention Reduces Achievement Gap between Underrepresented Minority and White Students in Introductory Biology Classes. (United States)

    Jordt, Hannah; Eddy, Sarah L; Brazil, Riley; Lau, Ignatius; Mann, Chelsea; Brownell, Sara E; King, Katherine; Freeman, Scott


    Achievement gaps between underrepresented minority (URM) students and their white peers in college science, technology, engineering, and mathematics classrooms are persistent across many white-majority institutions of higher education. Attempts to reduce this phenomenon of underperformance through increasing classroom structure via active learning have been partially successful. In this study, we address the hypothesis that the achievement gap between white and URM students in an undergraduate biology course has a psychological and emotional component arising from stereotype threat. Specifically, we introduced a values affirmation exercise that counters stereotype threat by reinforcing a student's feelings of integrity and self-worth in three iterations of an intensive active-learning college biology course. On average, this exercise reduced the achievement gap between URM and white students who entered the course with the same incoming grade point average. This result suggests that achievement gaps resulting from the underperformance of URM students could be mitigated by providing students with a learning environment that removes psychological and emotional impediments of performance through short psychosocial interventions. © 2017 H. Jordt et al. CBE—Life Sciences Education © 2017 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (

  16. Single Black Working Mothers' Perceptions: The Journey to Achieve Leadership Positions (United States)

    Raglin, Sherrell


    Single Black working mothers faced significant challenges in achieving high-level or senior-level leadership positions. The purpose of this qualitative narrative study was to collect, analyze and code the stories told by 10 participants to understand the perceptions and insights of the challenges and barriers single Black working mothers faced in…

  17. African American Homeschool Parents' Motivations for Homeschooling and Their Black Children's Academic Achievement (United States)

    Ray, Brian


    This study explores the motivations of African American parents for choosing homeschooling for their children and the academic achievement of their Black homeschool students. Their reasons for homeschooling are similar to those of homeschool parents in general, although some use homeschooling to help their children understand Black culture and…

  18. Closing the Reading Gap: Here's How An Urban Elementary School Succeeded In Closing A Huge Achievement Gap With An All-Out Effort Focused On Discipline And Literacy (United States)

    Petrilli, Peggy


    An elementary school principal describes her school's successful effort to virtually eliminate a reading gap between black and white students by concentrating on strong discipline and literacy programs, supplemented by music and foreign language programs that are believed to improve cognitive ability.

  19. Growth and gaps in mathematics achievement of students with and without disabilities on a statewide achievement test. (United States)

    Stevens, Joseph J; Schulte, Ann C; Elliott, Stephen N; Nese, Joseph F T; Tindal, Gerald


    This study estimated mathematics achievement growth trajectories in a statewide sample of 92,045 students with and without disabilities over Grades 3 to 7. Students with disabilities (SWDs) were identified in seven exceptionality categories. Students without disabilities (SWoDs) were categorized as General Education (GE) or Academically/Intellectually Gifted (AIG). Students in all groups showed significant growth that decelerated over grades as well as significant variability in achievement by student group, both at the initial assessment in Grade 3 and in rates of growth over time. Race/ethnicity, gender, parental education, free/reduced lunch status, and English language proficiency were also significant predictors of achievement. Effect size estimates showed substantial year-to-year growth that decreased over grades. Sizeable achievement gaps that were relatively stable over grades were observed between SWoDs and students in specific exceptionality categories. Our study also demonstrated the importance of statistically controlling for variation related to student demographic characteristics. Additional research is needed that expands on these results with the same and additional exceptionality groups. Copyright © 2014 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

  20. The Gender and Race Composition of Jobs and the Male/Female, White/Black Pay Gaps. (United States)

    Tomaskovic-Devey, Donald


    Analysis of North Carolina survey data indicates that females' average hourly wages were 71% of males', and blacks' wages were 78% of whites'. Human capital factors (educational attainment and occupational experience) explained 31% and 3% of the racial and gender gaps, respectively. Job gender composition explained 56% of the gender gap; job…

  1. Have Gender Gaps in Math Closed? Achievement, Teacher Perceptions, and Learning Behaviors across Two ECLS-K Cohorts (United States)

    Cimpian, Joseph R.; Lubienski, Sarah T.; Timmer, Jennifer D.; Makowski, Martha B.; Miller, Emily K.


    Studies using data from the Early Childhood Longitudinal Study-Kindergarten Class of 1998-1999 (ECLS-K:1999) revealed gender gaps in mathematics achievement and teacher perceptions. However, recent evidence suggests that gender gaps have closed on state tests, raising the question of whether such gaps are absent in the ECLS-K:2011 cohort.…

  2. Self-Esteem and Achievement of At-Risk Adolescent Black Males. (United States)

    Howerton, D. Lynn; And Others

    The relationship between self-esteem and academic achievement of at-risk adolescent black males was studied for 42 students in grades 6, 7, and 8. The Coopersmith Self-Esteem Inventory (SEI) was used to provide global measures of self-esteem. School grades and scores from the Stanford Achievement Test battery were used to measure academic…

  3. Closing achievement gaps with a utility-value intervention: Disentangling race and social class. (United States)

    Harackiewicz, Judith M; Canning, Elizabeth A; Tibbetts, Yoi; Priniski, Stacy J; Hyde, Janet S


    Many college students abandon their goal of completing a degree in science, technology, engineering, or math (STEM) when confronted with challenging introductory-level science courses. In the U.S., this trend is more pronounced for underrepresented minority (URM) and first-generation (FG) students, and contributes to persisting racial and social-class achievement gaps in higher education. Previous intervention studies have focused exclusively on race or social class, but have not examined how the 2 may be confounded and interact. This research therefore investigates the independent and interactive effects of race and social class as moderators of an intervention designed to promote performance, measured by grade in the course. In a double-blind randomized experiment conducted over 4 semesters of an introductory biology course (N = 1,040), we tested the effectiveness of a utility-value intervention in which students wrote about the personal relevance of course material. The utility-value intervention was successful in reducing the achievement gap for FG-URM students by 61%: the performance gap for FG-URM students, relative to continuing generation (CG)-Majority students, was large in the control condition, .84 grade points (d = .98), and the treatment effect for FG-URM students was .51 grade points (d = 0.55). The UV intervention helped students from all groups find utility value in the course content, and mediation analyses showed that the process of writing about utility value was particularly powerful for FG-URM students. Results highlight the importance of intersectionality in examining the independent and interactive effects of race and social class when evaluating interventions to close achievement gaps and the mechanisms through which they may operate. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  4. Special Education--Non-Special Education Achievement Gap in Math: Effects of Reporting Methods, Analytical Techniques, and Reclassification (United States)

    Thurlow, Martha L.; Wu, Yi-Chen; Lazarus, Sheryl S.; Ysseldyke, James E.


    Federal regulations indicate that the achievement gap must be closed between subgroups, including the gap between special education and non-special education students. We explored the ways in which achievement trends are influenced by three methods of reporting (cross-sectional, cohort-static, and cohort-dynamic). We also investigated (a) the ways…

  5. Myers–Perry black holes with scalar hair and a mass gap

    Energy Technology Data Exchange (ETDEWEB)

    Brihaye, Yves [Physique–Mathématique, Universite de Mons-Hainaut, Mons (Belgium); Herdeiro, Carlos; Radu, Eugen [Departamento de Física da Universidade de Aveiro and I3N, Campus de Santiago, 3810-183 Aveiro (Portugal)


    We construct a family of asymptotically flat, rotating black holes with scalar hair and a regular horizon, within five dimensional Einstein's gravity minimally coupled to a complex, massive scalar field doublet. These solutions are supported by rotation and have no static limit. They are described by their mass M, two equal angular momenta J{sub 1}=J{sub 2}≡J and a conserved Noether charge Q, measuring the scalar hair. For vanishing horizon size the solutions reduce to five dimensional boson stars. In the limit of vanishing Noether charge density, the scalar field becomes point-wise arbitrarily small and the geometry becomes, locally, arbitrarily close to that of a specific set of Myers–Perry black holes (MPBHs); but there remains a global difference with respect to the latter, manifest in a finite mass gap. Thus, the scalar hair never becomes a linear perturbation of MPBHs. This is a qualitative difference when compared to Kerr black holes with scalar hair [1]. Whereas the existence of the latter can be anticipated in linear theory, from the existence of scalar bound states on the Kerr geometry (i.e. scalar clouds), the hair of these MPBHs is intrinsically non-linear.

  6. Reducing the gender achievement gap in college science: a classroom study of values affirmation. (United States)

    Miyake, Akira; Kost-Smith, Lauren E; Finkelstein, Noah D; Pollock, Steven J; Cohen, Geoffrey L; Ito, Tiffany A


    In many science, technology, engineering, and mathematics disciplines, women are outperformed by men in test scores, jeopardizing their success in science-oriented courses and careers. The current study tested the effectiveness of a psychological intervention, called values affirmation, in reducing the gender achievement gap in a college-level introductory physics class. In this randomized double-blind study, 399 students either wrote about their most important values or not, twice at the beginning of the 15-week course. Values affirmation reduced the male-female performance and learning difference substantially and elevated women's modal grades from the C to B range. Benefits were strongest for women who tended to endorse the stereotype that men do better than women in physics. A brief psychological intervention may be a promising way to address the gender gap in science performance and learning.

  7. Teachers' perceptions of the effectiveness of an urban health sciences curriculum in closing the Black-White test score gap: A participatory case study (United States)

    Prince, Joan Marie


    Over the past years, progress in Black academic achievement, particularly in the area of science, has generally slowed or ceased. According to the 1994 NAEP assessment, twelfth-grade Black students are performing at the level of White eighth-grade students in the discipline of science (Department of Education, 1996). These students, in their last year of required schooling, are about to graduate, yet they lag at least four years behind their white counterparts in science achievement. Despite the establishment and implementation of numerous science intervention programs, Black students still suffer from a disparate gap in standardized test score achievement. The purpose of this research is to investigate teachers' perceptions of the effectiveness of an urban sciences intervention tool that was designed to assist in narrowing the Black-White science academic achievement gap. Specifically, what factors affect teachers' personal sense of instructional efficacy, and how does this translate into their outcome expectancy for student academic success? A multiple-case, replicative design, grounded in descriptive theory, was selected for the study. Multiple sources of evidence were queried to provide robust findings. These sources included a validated health sciences self-efficacy instrument, an interview protocol, a classroom observation, and a review of archival material that included case study participants' personnel files and meeting minutes. A cross-comparative analytic approach was selected for interpretation (Yin, 1994). Findings indicate that teachers attribute the success or failure of educational intervention tools in closing the Black-White test score gap to a variety of internal and external factors. These factors included a perceived lack of both monetary and personal support by the school leadership, as well as a perceived lack of parental involvement which impacted negatively on student achievement patterns. The case study participants displayed a depressed

  8. Teachers' perceptions of students' mathematics proficiency may exacerbate early gender gaps in achievement. (United States)

    Robinson-Cimpian, Joseph P; Lubienski, Sarah Theule; Ganley, Colleen M; Copur-Gencturk, Yasemin


    A recent wave of research suggests that teachers overrate the performance of girls relative to boys and hold more positive attitudes toward girls' mathematics abilities. However, these prior estimates of teachers' supposed female bias are potentially misleading because these estimates (and teachers themselves) confound achievement with teachers' perceptions of behavior and effort. Using data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (ECLS-K), Study 1 demonstrates that teachers actually rate boys' mathematics proficiency higher than that of girls when conditioning on both teachers' ratings of behavior and approaches to learning as well as past and current test scores. In other words, on average girls are only perceived to be as mathematically competent as similarly achieving boys when the girls are also seen as working harder, behaving better, and being more eager to learn. Study 2 uses mediation analysis with an instrumental-variables approach, as well as a matching strategy, to explore the extent to which this conditional underrating of girls may explain the widening gender gap in mathematics in early elementary school. We find robust evidence suggesting that underrating girls' mathematics proficiency accounts for a substantial portion of the development of the mathematics achievement gap between similarly performing and behaving boys and girls in the early grades. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  9. Enhancing the Employability of Chinese International Students: Identifying Achievements and Gaps in the Research Field

    Directory of Open Access Journals (Sweden)

    Xuemeng Cao


    Full Text Available This article shows what achievements have been made by existing studies on graduate employability, and what gaps need to be filled in this field. It starts with a retrospective account of the changing concept of employability, followed by a presentation of the practices that have been used to support graduate employability enhancement in different countries. Moreover, this article gives a critical review of Chinese contexts of graduate labour market. Last but not least, limitations of existing studies are identified, which reflect an expectation for future research on graduate employability to meet the demand of an increasingly international dimension of higher education.

  10. Black Father Involvement in Gifted Education: Thoughts from Black Fathers on Increasing/Improving Black Father-Gifted Teacher Partnerships (United States)

    Grantham, Tarek C.; Henfield, Malik S.


    Black fathers are important advocates in addressing the underrepresentation of Black students in gifted programs, as well as the achievement gaps between Black and White students. Black fathers increasingly understand the important role that Black mothers have traditionally played in supporting their gifted children's school experiences. As a…

  11. Social and behavioral skills and the gender gap in early educational achievement. (United States)

    Diprete, Thomas A; Jennings, Jennifer L


    Though many studies have suggested that social and behavioral skills play a central role in gender stratification processes, we know little about the extent to which these skills affect gender gaps in academic achievement. Analyzing data from the Early Child Longitudinal Study-Kindergarten Cohort, we demonstrate that social and behavioral skills have substantively important effects on academic outcomes from kindergarten through fifth grade. Gender differences in the acquisition of these skills, moreover, explain a considerable fraction of the gender gap in academic outcomes during early elementary school. Boys get roughly the same academic return to social and behavioral skills as their female peers, but girls begin school with more advanced social and behavioral skills and their skill advantage grows over time. While part of the effect may reflect an evaluation process that rewards students who better conform to school norms, our results imply that the acquisition of social and behavioral skills enhances learning as well. Our results call for a reconsideration of the family and school-level processes that produce gender gaps in social and behavioral skills and the advantages they confer for academic and later success. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Healthier students are better learners: a missing link in school reforms to close the achievement gap. (United States)

    Basch, Charles E


    This article provides an introduction to the October 2011 special issue of the Journal of School Health on "Healthier Students Are Better Learners." Literature was reviewed and synthesized to identify health problems affecting school-aged youth that are highly prevalent, disproportionately affect urban minority youth, directly and indirectly causally affect academic achievement, and can be feasibly and effectively addressed through school health programs and services. Based on these criteria, 7 educationally relevant health disparities were selected as strategic priorities to help close the achievement gap: (1) vision, (2) asthma, (3) teen pregnancy, (4) aggression and violence, (5) physical activity, (6) breakfast, and (7) inattention and hyperactivity. Research clearly shows that these health problems influence students' motivation and ability to learn. Disparities among urban minority youth are outlined, along with the causal pathways through which each adversely affects academic achievement, including sensory perceptions, cognition, school connectedness, absenteeism, and dropping out. Evidence-based approaches that schools can implement to address these problems are presented. These health problems and the causal pathways they influence have interactive and a synergistic effect, which is why they must be addressed collectively using a coordinated approach. No matter how well teachers are prepared to teach, no matter what accountability measures are put in place, no matter what governing structures are established for schools, educational progress will be profoundly limited if students are not motivated and able to learn. Particular health problems play a major role in limiting the motivation and ability to learn of urban minority youth. This is why reducing these disparities through a coordinated approach warrants validation as a cohesive school improvement initiative to close the achievement gap. Local, state, and national policies for implementing this

  13. Daily online testing in large classes: boosting college performance while reducing achievement gaps.

    Directory of Open Access Journals (Sweden)

    James W Pennebaker

    Full Text Available An in-class computer-based system, that included daily online testing, was introduced to two large university classes. We examined subsequent improvements in academic performance and reductions in the achievement gaps between lower- and upper-middle class students in academic performance. Students (N = 901 brought laptop computers to classes and took daily quizzes that provided immediate and personalized feedback. Student performance was compared with the same data for traditional classes taught previously by the same instructors (N = 935. Exam performance was approximately half a letter grade above previous semesters, based on comparisons of identical questions asked from earlier years. Students in the experimental classes performed better in other classes, both in the semester they took the course and in subsequent semester classes. The new system resulted in a 50% reduction in the achievement gap as measured by grades among students of different social classes. These findings suggest that frequent consequential quizzing should be used routinely in large lecture courses to improve performance in class and in other concurrent and subsequent courses.

  14. Moving on Up: Urban to Suburban Translocation Experiences of High-Achieving Black American Students (United States)

    Yu, Xiaoqi; Seeberg, Vilma; Malone, Larissa


    Minority suburbanization has been a fast growing demographic shift in the United States during the first decade of the 21st century. This article examines the tapestry of the suburbanization experience of a group of high-achieving Black American students and their families as told by them. Departing from the all too common, deficit orientation…

  15. Math Achievement Trajectories among Black Male Students in the Elementary- and Middle-School Years (United States)

    Zilanawala, Afshin; Martin, Margary; Noguera, Pedro A.; Mincy, Ronald B.


    In this article, we analyze the variation in math achievement trajectories of Black male students to understand the different ways these students successfully or unsuccessfully navigate schools and the school characteristics that are associated with their trajectories. Using longitudinal student-level data from a large urban US city (n = 7,039),…

  16. Inattention and hyperactivity and the achievement gap among urban minority youth. (United States)

    Basch, Charles E


    To outline the prevalence and disparities of inattention and hyperactivity among school-aged urban minority youth, causal pathways through which inattention and hyperactivity adversely affects academic achievement, and proven or promising approaches for schools to address these problems. Literature review. Approximately 4.6 million (8.4%) of American youth aged 6-17 have received a diagnosis of attention deficit/hyperactivity disorder (ADHD), and almost two thirds of these youth are reportedly under treatment with prescription medications. Urban minority youth are not only more likely to be affected but also less likely to receive accurate diagnosis and treatment. Causal pathways through which ADHD may affect academic achievement include sensory perceptions, cognition, school connectedness, absenteeism, and dropping out. In one study, youth with diagnosed ADHD were 2.7 times as likely to drop out (10.0% vs. 22.9%). A similar odds ratio for not graduating from high school was found in another prospective study, with an 8-year follow-up period (odds ratio = 2.4). There are many children who are below the clinical diagnostic threshold for ADHD but who exhibit signs and symptoms that interfere with learning. Evidence-based programs emphasizing functional academic and social outcomes are available. Inattention and hyperactivity are highly and disproportionately prevalent among school-aged urban minority youth, have a negative impact on academic achievement through their effects on sensory perceptions, cognition, school connectedness, absenteeism, and dropping out, and effective practices are available for schools to address these problems. This prevalent and complex syndrome has very powerful effects on academic achievement and educational attainment, and should be a high priority in efforts to help close the achievement gap. © 2011, American School Health Association.

  17. The achievement gap: Should we rely on SAT scores to tell us anything about it?

    Directory of Open Access Journals (Sweden)

    Dale Whittington


    Full Text Available Increasing numbers of students taking the SAT have declined to identify their race/ethnicity. I examined the impact of non-respondents on the validity of reported racial/ethnic differences and year-to-year changes in test performance. Using an analysis reported by Wainer (1988 and SAT data from 1996 to 2003, I confirmed Wainer’s findings that non-respondents prevent accurate estimations of group differences based on SAT data. I then explored the impact of College Board press release information on news reports about the achievement gap. I found frequent reports of racial/ethnic differences in SAT scores and year-to-year changes in scores but negligible consideration of non-respondents. Press releases and media reports should include information about non-respondents and their impact on accuracy of reported differences based on race/ethnicity.

  18. Educational Achievement Gaps between Immigrant and Native Students in Two “New Immigration Countries”: Italy and Spain in comparison (United States)

    Azzolini, Davide; Schnell, Philipp; Palmer, John


    We use PISA 2009 data to determine how immigrant children in Italy and Spain compare with native students in reading and mathematics skills. Drawing on the vast empirical literature in traditional immigration countries, we test the extent to which the most well-established patterns and hypotheses of immigrant/native educational achievement gaps also apply to these new immigration countries. Findings show that both first- and second-generation immigrant students underperform natives in both countries. Although socioeconomic background and language skills contribute to the explanation of achievement gaps, significant differences remain within countries. While modeling socioeconomic background reduces the observed gaps to a very similar extent in the two countries, language spoken at home is more strongly associated with achievement in Italy. School-type differentiation, such as tracking in Italy and school ownership in Spain, do not reduce immigrant/native gaps, although in Italy tracking is strongly associated with students’ test scores. PMID:23493944

  19. Mind the Gap: 20 Years of Progress and Retrenchment in School Funding and Achievement Gaps. Policy Information Report. ETS RR-16-15 (United States)

    Baker, Bruce D.; Farrie, Danielle; Sciarra, David G.


    Although there has been significant progress in the long term, achievement gaps among the nation's students persist.Many factors have contributed to the disparities in outcomes, and societal changes can explain progress, or lack thereof, over the past few decades.This is well documented in the 2010 Educational Testing Service (ETS) report…

  20. Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms (United States)

    Brownell, Sara E.; Wenderoth, Mary Pat


    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel. PMID:25185231

  1. The Home/School Connection and Its Role in Narrowing the Academic Achievement Gap: An Ecological Systems Theoretical Perspective (United States)

    Blandin, Allyson


    This literature review seeks to evaluate previous studies on the topic of the home/school connection and its role in enhancing students' academic achievement and narrowing the academic achievement gap. The ecological systems theory framework will facilitate the discussion of the importance of the home/school connection phenomenon. Perspectives…

  2. Disproportionality Fills in the Gaps: Connections between Achievement, Discipline and Special Education in the School-to-Prison Pipeline (United States)

    Annamma, Subini; Morrison, Deb; Jackson, Darrell


    The focus on the achievement gap has overshadowed ways in which school systems constrain student achievement through trends of racial disproportionality in areas such as school discipline, special education assignment, and juvenile justice. Using Critical Race Theory, we reframe these racial disparities as issues of institutionalized racism.…

  3. Digestion coefficients achieved by the black rhinoceros (Diceros bicornis), a large browsing hindgut fermenter. (United States)

    Clauss, M; Castell, J C; Kienzle, E; Dierenfeld, E S; Flach, E J; Behlert, O; Ortmann, S; Streich, W J; Hummel, J; Hatt, J-M


    In contrast to the grazing white (C. simum) and Indian (R. unicornis) rhinoceros, the black rhinoceros (D. bicornis) is an exclusive browser. Due to the particular fermentation characteristics of browse, one would expect browsers to display both shorter ingesta retention times and lower digestion coefficients on comparable diets than grazers. In order to generate a database to test this hypothesis, we performed digestibility studies in eight black rhinoceroses (D. bicornis) from three zoological institutions, using total faecal collection for the quantification of faecal output. One to three regularly fed zoo rations of roughage, concentrates and varying proportions of browse material were used per animal. Additional data was taken from three hitherto unpublished studies as well as several published sources. When compared with horses on similar rations, black rhinoceroses achieved lower digestion coefficients for organic matter and CF. In general, an increase in dietary CF content led to a steeper decrease in organic matter and GE digestibility in black rhinoceroses than in horses. When comparing available data for rhinoceroses, browsing species showed a steeper decrease in organic matter digestibility than grazing species with increasing dietary cell wall content. Endogenous losses as determined by linear regression analysis were within the range reported for horses and Indian rhinoceroses. The results suggest that the horse is not a useful model animal for evaluating diets for black rhinoceroses energetically. In general, diets fed to captive black rhinoceroses seem to include higher proportions of concentrates than diets for other rhinoceros species, and an increase in browse or roughage would reduce digestion coefficients to levels observed in animals fed natural forage.

  4. Achieving high survival of tournament-caught black bass: past efforts and future needs and opportunities (United States)

    Schramm, Harold; Gilliland, Gene


    Rapid growth of black bass (Micropterus spp.) tournaments in the 1960s and 1970s caused concern among fisheries managers and anglers about the impacts of tournament-caused mortality on bass populations. Tournament organizers voluntarily implemented live-release events in the early 1980s. As catch-and-release practices became more common, procedures to improve the survival of tournament-caught fish were developed and have evolved. The objectives of this paper are to review education and outreach efforts to improve survival of tournament-caught black bass, suggest research needs and opportunities to achieve greater survival, and show the relevance of high survival to contemporary black bass management. Since 1985, a succession of informational products describing those techniques have been developed and distributed to anglers. Although research has confirmed the effectiveness of the recommended procedures and documented that angler and tournament organizer behavior has changed and the survival of tournament-caught black bass has increased, the impacts of the outreach efforts on tournament practices have not been quantified. Continued efforts towards increasing angler awareness of proper handling techniques may benefit from better communication, endorsement by professional anglers, and the use of incentives by state agencies to encourage better fish care.

  5. Gender gaps in achievement and participation in multiple introductory biology classrooms. (United States)

    Eddy, Sarah L; Brownell, Sara E; Wenderoth, Mary Pat


    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large introductory biology classes for majors, we examine two measures of gender disparity in biology: academic achievement and participation in whole-class discussions. We found that females consistently underperform on exams compared with males with similar overall college grade point averages. In addition, although females on average represent 60% of the students in these courses, their voices make up less than 40% of those heard responding to instructor-posed questions to the class, one of the most common ways of engaging students in large lectures. Based on these data, we propose that, despite numerical dominance of females, gender disparities remain an issue in introductory biology classrooms. For student retention and achievement in biology to be truly merit based, we need to develop strategies to equalize the opportunities for students of different genders to practice the skills they need to excel. © 2014 S. L. Eddy et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (

  6. Race, Socioeconomic Status, and Implicit Bias: Implications for Closing the Achievement Gap (United States)

    Schlosser, Elizabeth Auretta Cox

    This study accessed the relationship between race, socioeconomic status, age and the race implicit bias held by middle and high school science teachers in Mobile and Baldwin County Public School Systems. Seventy-nine participants were administered the race Implicit Association Test (race IAT), created by Greenwald, A. G., Nosek, B. A., & Banaji, M. R., (2003) and a demographic survey. Quantitative analysis using analysis of variances, ANOVA and t-tests were used in this study. An ANOVA was performed comparing the race IAT scores of African American science teachers and their Caucasian counterparts. A statically significant difference was found (F = .4.56, p = .01). An ANOVA was also performed using the race IAT scores comparing the age of the participants; the analysis yielded no statistical difference based on age. A t-test was performed comparing the race IAT scores of African American teachers who taught at either Title I or non-Title I schools; no statistical difference was found between groups (t = -17.985, p .001). This research examines the implications of the achievement gap among African American and Caucasian students in science.

  7. Achievement gaps and correlates of early mathematics achievement: Evidence from the ECLS K—first grade sample. Vol. 13 No. 46

    Directory of Open Access Journals (Sweden)

    Madhabi Chatterji


    Full Text Available In light of the NCLB Act of 2001, this study estimated mathematics achievement gaps in different subgroups of kindergartners and first graders, and identified child- and school-level correlates and moderators of early mathematics achievement. A subset of 2300 students nested in 182 schools from the Early Childhood Longitudinal Study K-First Grade data set was analyzed with hierarchical linear models. Relative to school mean estimates at the end of kindergarten, significant mathematics achievement gaps were found in Hispanics, African Americans and high poverty students. At the end of Grade 1, mathematics gaps were significant in African American, high poverty, and female subgroups, but not in Hispanics. School-level correlates of Grade 1 Mathematics achievement were class size (with a small negative main effect, at-home reading time by parents (with a large positive main effect and school size (with a small positive main effect. Cross-level interactions in Grade 1 indicated that schools with larger class and school sizes had a negative effect on African American children's math scores; schools giving more instructional time to reading and math had a positive effect on high poverty students' scores, and schools with higher elementary teacher certification rates had a positive effect on boys' mathematics achievement.

  8. Tutoring: Its Effects on Reading Achievement, Standard-Setting and Affect-Mediating Self-Evaluation for Black Male Under-Achievers in Reading. (United States)

    Liette, Eileen Evelyn

    The effects of a tutor-tutee relationship on the reading achievement and achievement motivation of underachieving black male children were investigated. A group of 41 tutees and their controls as well as a group of 41 tutors and their controls, all from lower socioeconomic backgrounds, were randomly selected. All subjects were given a nonverbal IQ…

  9. The Development of Gender Achievement Gaps in Mathematics and Reading during Elementary and Middle School: Examining Direct Cognitive Assessments and Teacher Ratings (United States)

    Robinson, Joseph Paul; Lubienski, Sarah Theule


    Using K-8 national longitudinal data, the authors investigate males' and females' achievement in math and reading, including when gender gaps first appear, whether the appearance of gaps depends on the metric used, and where on the achievement distribution gaps are most prevalent. Additionally, teachers' assessments of males and females are…

  10. No More Profiling in the Classroom: A Midsize Urban School District's Efforts to Close the Achievement Gap (United States)

    Smith-Evans, Leticia Victoria


    For approximately a third of this decade, a mid-size urban school district took a bold step in its continuing efforts to battle what has been a persistent problem plaguing this Nation's education system for decades or possibly for as long as it has existed--the achievement gap between students of color and their White peers. The district has…

  11. Whites Aren't Bad, Asian Americans Are Just Better: Asymmetrical Attributions for the White-Asian American Achievement Gap (United States)

    Sperling, Rick; Zwahr-Castro, Jennifer; Cruz, Felicia; Montalvo, Jason


    Previous research has shown that people often engage in cultural-deficit thinking when reasoning about racial/ethnic achievement gaps. However, it is unclear whether culture-blaming explanations are best thought of as group-level internal attributions, expressions of prejudice against a lower status group, or self-serving bias. In this study,…

  12. Patterns and Trends in Achievement Gaps in Malaysian Secondary Schools (1999-2011): Gender, Ethnicity, and Socioeconomic Status (United States)

    Saw, Guan Kung


    Educational inequality is a highly debated yet empirically understudied topic in Malaysia. This paper examines the patterns and trends of academic achievement gaps by student social groups in Malaysia, drawing upon nationally representative data for the most recent four cohorts (1999, 2003, 2007, and 2011) of eighth-grade Malaysian students from…

  13. The School Age Gender Gap in Reading Achievement: Examining the Influences of Item Format and Intrinsic Reading Motivation (United States)

    Schwabe, Franziska; McElvany, Nele; Trendtel, Matthias


    The importance of reading competence for both individuals and society underlines the strong need to understand the gender gap in reading achievement. Beyond mean differences in reading comprehension, research has indicated that girls possess specific advantages on constructed-response items compared with boys of the same reading ability. Moreover,…

  14. Could Trends in Time Children Spend with Parents Help Explain the Black-White Gap in Human Capital? Evidence from the American Time Use Survey (United States)

    Patterson, Richard W.


    It is widely believed that the time children spend with parents significantly impacts human capital formation. If time varies significantly between black and white children, this may help explain the large racial gap in test scores and wages. In this study, I use data from the American Time Use Survey to examine the patterns in the time black and…

  15. Black guillemot ecology in relation to tidal stream energy generation: An evaluation of current knowledge and information gaps. (United States)

    Johnston, Daniel T; Furness, Robert W; Robbins, Alexandra M C; Tyler, Glen; Taggart, Mark A; Masden, Elizabeth A


    The black guillemot Cepphus grylle has been identified as a species likely to interact with marine renewable energy devices, specifically tidal turbines, with the potential to experience negative impacts. This likelihood is primarily based on the species being a diving seabird, and an inshore, benthic forager often associating with tidal streams. These behavioural properties may bring them into contact with turbine blades, or make them susceptible to alterations to tidal current speed, and/or changes in benthic habitat structure. We examine the knowledge currently available to assess the potential impacts of tidal stream turbines on black guillemot ecology, highlight knowledge gaps and make recommendations for future research. The key ecological aspects investigated include: foraging movements, diving behaviour, seasonal distribution, other sources of disturbance and colony recovery. Relating to foraging behaviour, between studies there is heterogeneity in black guillemot habitat use in relation to season, tide, diurnal cycles, and bathymetry. Currently, there is also little knowledge regarding the benthic habitats associated with foraging. With respect to diving behaviour, there is currently no available research regarding how black guillemots orientate and manoeuvre within the water column. Black guillemots are considered to be a non-migratory species, however little is known about their winter foraging range and habitat. The effect of human disturbance on breeding habitat and the metapopulation responses to potential mortalities are unknown. It is clear further understanding of black guillemot foraging habitat and behaviour is needed to provide renewable energy developers with the knowledge to sustainably locate tidal turbines and mitigate their impacts. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Dollars for Sense: Assessing Achievement Gaps in Arkansas in the Context of Substantial Funding Increases (United States)

    Barnett, Joshua; Jensen, Nathan C.; Ritter, Gary W.


    Forty-four of the fifty states have experienced school finance lawsuits as a consequence of funding gaps between rich and poor districts. In some states, such as Kentucky, lawsuits brought about by property-poor districts have resulted in a statewide remedy that reforms the property tax system and seeks to provide every child with an adequate…

  17. Gender Gaps in Achievement and Participation in Multiple Introductory Biology Classrooms (United States)

    Eddy, Sarah L.; Brownell, Sara E.; Wenderoth, Mary Pat


    Although gender gaps have been a major concern in male-dominated science, technology, engineering, and mathematics disciplines such as physics and engineering, the numerical dominance of female students in biology has supported the assumption that gender disparities do not exist at the undergraduate level in life sciences. Using data from 23 large…

  18. The Gap between Advantaged and Disadvantaged Students in Science Achievement in South African Secondary Schools (United States)

    Howie, Sarah; Scherman, Vanessa; Venter, Elsie


    South Africa's education system is still deep in the throes of reform under its third Minister of Education since 1994. Poor communities, in particular those of rural Africans, bear the brunt of the past inequalities. The challenge was to explore the extent of the "gap" in students' scores by comparing the advantaged and disadvantaged…

  19. Gender and Minority Achievement Gaps in Science in Eighth Grade: Item Analyses of Nationally Representative Data. Research Report. ETS RR-17-36 (United States)

    Qian, Xiaoyu; Nandakumar, Ratna; Glutting, Joseoph; Ford, Danielle; Fifield, Steve


    In this study, we investigated gender and minority achievement gaps on 8th-grade science items employing a multilevel item response methodology. Both gaps were wider on physics and earth science items than on biology and chemistry items. Larger gender gaps were found on items with specific topics favoring male students than other items, for…

  20. The Economic Benefits of Closing Educational Achievement Gaps: Promoting Growth and Strengthening the Nation by Improving the Educational Outcomes of Children of Color (United States)

    Lynch, Robert G.; Oakford, Patrick


    Our nation is currently experiencing growing levels of income and wealth inequality, which are contributing to longstanding racial and ethnic gaps in education outcomes and other areas. This report quantifies the economic benefits of closing one of the most harmful racial and ethnic gaps: the educational achievement gap that exists between black…

  1. Issues for Achieving an Experimental Model Concerning Bubble Deck Concrete Slab with Spherical Gaps

    Directory of Open Access Journals (Sweden)

    Sergiu Călin


    Full Text Available After realizing numerous constructions in the world, which use Bubble Deck concrete slabs with spherical gaps, valuable information were gathered, allowing a rigorous processing and systematization, with the purpose of realizing an experimental and documentary study. The paper presents some experimental programs which refer to concrete slabs with spherical gaps, existing in similar execution and loading conditions as those from a real construction; this implies the realization of a monolithic slab element at a scale of 1:1, which will be subjected to static gravitational loadings in order to determine the deformation (deflection, cracking and failing characteristics. The resultant conclusions will be used in defining the failing mechanisms, very useful in the formulation of an adequate mathematical model. The research proposed in the project offers an answer to the major objectives of the development of calculus methods and existent prescriptions of the concrete slabs with spherical gaps. The realization of the proposed objectives involves documentation activities, theoretical study, collaboration with different other partners, gathering and processing of the results obtained in laboratory and even in situ.

  2. The Gender Confidence Gap in Fractions Knowledge: Gender Differences in Student Belief-Achievement Relationships (United States)

    Ross, John A.; Scott, Garth; Bruce, Catherine D.


    Recent research demonstrates that in many countries gender differences in mathematics achievement have virtually disappeared. Expectancy-value theory and social cognition theory both predict that if gender differences in achievement have declined there should be a similar decline in gender differences in self-beliefs. Extant literature is…

  3. The Dutch gender gap in mathematics: Small for achievement, substantial for beliefs and attitudes

    NARCIS (Netherlands)

    Meelissen, Martina R.M.; Luyten, Johannes W.


    In general, studies on gender and mathematics show that the advantage held by boys over girls in mathematics achievement has diminished markedly over the last 40 years. Some researchers even argue that gender differences in mathematics achievement are no longer a relevant issue. However, the results

  4. Explaining the Achievement Gap between Indigenous and Non-Indigenous Students: An Analysis of PISA 2009 Results for Australia and New Zealand (United States)

    Song, Steve; Perry, Laura B.; McConney, Andrew


    This study investigates the relative roles of home and school variables in accounting for achievement gaps between Indigenous and non-Indigenous students in Australia and New Zealand. Using data from the Programme for International Student Assessment [PISA] 2009, our findings show that achievement gaps between Indigenous and non-Indigenous…

  5. Classroom-Based Inequalities and Achievement Gaps in First Grade: The Role of Classroom Context and Access to Qualified and Effective Teachers (United States)

    Palardy, Gregory J.


    Background: An enduring question about achievement gaps is, which aspects of schools contribute most? At the early grade levels, when children spend the vast majority of their school day in a single classroom with a single teacher, school inequities that correlate with achievement gaps likely originate within the classroom. This study examined the…

  6. Bridging the gap: the roles of social capital and ethnicity in medical student achievement. (United States)

    Vaughan, Suzanne; Sanders, Tom; Crossley, Nick; O'Neill, Paul; Wass, Val


    Within medical education, there is a discrepancy between the achievement level of White students and that of their ethnic minority peers. The processes underlying this disparity have not been adequately investigated or explained. This study utilises social network analysis to investigate the impact of relationships on medical student achievement by ethnicity, specifically by examining homophily (the tendency to interact with others in the same group) by ethnicity, age and role. Data from a cross-sectional social network study conducted in one UK medical school are presented and are analysed alongside examination records obtained from the medical school. Participants were sampled across the four hospital placement sites; a total of 158 medical students in their clinical phase (Years 3 and 4) completed the survey. The research was designed and analysed using social capital theory. Although significant patterns of ethnic and religious homophily emerged, no link was found between these factors and achievement. Interacting with problem-based learning (PBL) group peers in study-related activities, and having seniors in a wider academic support network were directly linked to better achievement. Students in higher academic quartiles were more likely to be named by members of their PBL group in study activities and to name at least one tutor or clinician in their network. Students from lower-achieving groups were least likely to have the social capital enabling, and resulting from, interactions with members of more expert social groups. Lower levels of the social capital that mediates interaction with peers, tutors and clinicians may be the cause of underperformance by ethnic minority students. Because of ethnic homophily, minority students may be cut off from potential and actual resources that facilitate learning and achievement. © 2014 John Wiley & Sons Ltd.

  7. Does Class-Size Reduction Close the Achievement Gap? Evidence from TIMSS 2011 (United States)

    Li, Wei; Konstantopoulos, Spyros


    Policies about reducing class size have been implemented in the US and Europe in the past decades. Only a few studies have discussed the effects of class size at different levels of student achievement, and their findings have been mixed. We employ quantile regression analysis, coupled with instrumental variables, to examine the causal effects of…

  8. Analyzing the Gender Gap in Math Achievement: Evidence from a Large-Scale US Sample (United States)

    Cheema, Jehanzeb R.; Galluzzo, Gary


    The US portion of the Program for International Student Assessment (PISA) 2003 student questionnaire comprising of 4,733 observations was used in a multiple regression framework to predict math achievement from demographic variables, such as gender, race, and socioeconomic status, and two student-specific measures of perception, math anxiety and…

  9. Equity and Spatial Reasoning: Reducing the Mathematical Achievement Gap in Gender and Social Disadvantage (United States)

    Lowrie, Tom; Jorgensen, Robyn


    Since the early 70s, there has been recognition that there are specific differences in achievement based on variables, such as gender and socio-economic background, in terms of mathematics performance. However, these differences are not unilateral but rather quite specific and relate strongly to spatial reasoning. This early work has paved the way…

  10. The Achievement Gap among Newcomer Immigrant Adolescents: Life Stressors Hinder Latina/o Academic Success (United States)

    Patel, Sita G.; Barrera, Alinne Z.; Strambler, Michael J.; Muñoz, Ricardo F.; Macciomei, Erynn


    This study compares life stressors and school outcomes among newcomer immigrant adolescents from Latin America, Asia, and the Caribbean. Participants attended a predominantly low-income, urban international public high school in the northeast. The Latina/o students were exposed to more life stressors and had lower attendance and achievement than…

  11. Actively Closing the Gap? Social Class, Organized Activities, and Academic Achievement in High School (United States)

    Morris, David S.


    Participation in Organized Activities (OA) is associated with positive behavioral and developmental outcomes in children. However, less is known about how particular aspects of participation affect the academic achievement of high school students from different social class positions. Using the Education Longitudinal Study of 2002, this study…

  12. The Distribution of Pedagogical Content Knowledge in Cambodia: Gaps and Thresholds in Math Achievement (United States)

    Ngo, Federick J.


    Increasing teacher quality is a major objective of recent Cambodian education policy. In mathematics education literature, pedagogical content knowledge (PCK) has emerged as a critical component of teacher quality that is strongly linked to student achievement. In this study I use data from a large survey of Cambodian schools to investigate the…

  13. Latino English Language Learners: Bridging Achievement and Cultural Gaps between Schools and Families (United States)

    Good, Mary Ellen; Masewicz, Sophia; Vogel, Linda


    This qualitative study grounded in critical inquiry and cultural-ecological theory explores barriers to academic achievement for Latino English language learners (ELLs). Parents and teachers were purposefully selected from a rural school district in the Rocky Mountain region to participate in focus group interviews. Findings included barriers…

  14. Leading Causes of Death Contributing to Decrease in Life Expectancy Gap Between Black and White Populations: United States, 1999-2013. (United States)

    Kochanek, Kenneth D; Anderson, Robert N; Arias, Elizabeth


    Life expectancy at birth has increased steadily since 1900 to a record 78.8 years in 2013. But differences in life expectancy between the white and black populations still exist, despite a decrease in the life expectancy gap from 5.9 years in 1999 to 3.6 years in 2013. Differences in the change over time in the leading causes of death for the black and white populations have contributed to this decrease in the gap in life expectancy. Between 1999 and 2013, the decrease in the life expectancy gap between the black and white populations was mostly due to greater decreases in mortality from heart disease, cancer, HIV disease, unintentional injuries, and perinatal conditions among the black population. Similarly, the decrease in the gap between black and white male life expectancy was due to greater decreases in death rates for HIV disease, cancer, unintentional injuries, heart disease, and perinatal conditions in black males. For black females, greater decreases in diabetes death rates, combined with decreased rates for heart disease and HIV disease, were the major causes contributing to the decrease in the life expectancy gap with white females. The decrease in the gap in life expectancy between the white and black populations would have been larger than 3.6 years if not for increases in death rates for the black population for aortic aneurysm, Alzheimer’s disease, and maternal conditions. For black males, the causes that showed increases in death rates over white males were hypertension, aortic aneurysm, diabetes, Alzheimer’s disease, and kidney disease, while the causes that showed increases in death rates for black females were Alzheimer’s disease, maternal conditions, and atherosclerosis. This NCHS Data Brief is the second in a series of data briefs that explore the causes of death contributing to differences in life expectancy between detailed ethnic and racial populations in the United States. The first data brief focused on the racial differences in life

  15. Equity and spatial reasoning: reducing the mathematical achievement gap in gender and social disadvantage (United States)

    Lowrie, Tom; Jorgensen, Robyn


    Since the early 70s, there has been recognition that there are specific differences in achievement based on variables, such as gender and socio-economic background, in terms of mathematics performance. However, these differences are not unilateral but rather quite specific and relate strongly to spatial reasoning. This early work has paved the way for thinking critically about who achieves in mathematics and why. This project innovatively combines the strengths of the two Chief Investigators—Lowrie's work in spatial reasoning and Jorgensen's work in equity. The assumptions, the approach and theoretical framing used in the study unite quite disparate areas of mathematics education into a cogent research program that seeks to challenge some of the long-held views in the field of mathematics education.

  16. Connecting Self-Esteem and Achievement: Diversity in Academic Identification and Dis-Identification Patterns among Black College Students (United States)

    Hope, Elan C.; Chavous, Tabbye M.; Jagers, Robert J.; Sellers, Robert M.


    Using a person-oriented approach, we explored patterns of self-esteem and achievement among 324 Black college students across the freshman college year and identified four academic identification profiles. Multivariate analyses revealed profile differences in academic and psychological outcomes at beginning and end of freshman year (academic…

  17. HIV/AIDS Situation in Economic Cooperation Countries; Achievement and Gaps toward Millennium Development Goals

    Directory of Open Access Journals (Sweden)

    Ghobad Moradi


    Conclusion: An efficient surveillance system in needed to illustrate an exact picture of HIV/AIDS in all countries. This study shows that though the epidemics has started lately in member countries compared with other parts of the world, no proper intervention has been adopted for controlling the epidemics yet. Moreover, in those countries which AIDS epidemics are concentrated among drug users, harm reduction activities are necessary to control the problem. Increasing the coverage of antiretroviral treatment and awareness of general and high risk population could help countries to achieve HIV/AIDS indicators.

  18. Exploring the middle school science achievement gap: Influences of curriculum, instruction and students' perceptions (United States)

    Winning, Rosalie Anne

    Students' science achievement has been subject to scrutiny and criticism in the United States. The decline in rankings on standardized international assessments has been the focus of concern for educators, policy makers, parents and society at large. This study, designed as an action research, explored the factors contributing to the decrease in the number of students attaining advanced proficiency in science learning as measured by state assessments in grades four and eight in a New Jersey school district. Specifically, this study addressed the degree to which the middle school curriculum reflected the national science framework standards for 21st century leaning and the New Jersey Core Curriculum Content Standards; the pedagogical approaches regularly planned and implemented in the middle school science classrooms; and the students' perceptions of their science learning. Research data were collected by teacher and student surveys, focus group discussions, student interviews, document reviews of written curricula, and classroom observations. An important disparity emerged between the document analysis of the local curriculum and the teachers' views that 21st century learning skills are reflected in the written curriculum and classroom pedagogy. Further, classroom observations revealed the prevalence of a traditional pedagogy, focused on repetition of teacher-disseminated information and featuring limited differentiation, inquiry-based or constructivist learning strategies. The students expressed a value for discovery and collaboration with peers in order to develop, share and refine their understanding of science. The research concluded with recommendations for a revised curriculum process, sustained and collaborative professional development, on-going formative assessments of student learning and the formal integration of an online student science blog as a means of encouraging the co-construction of deep and enduring science knowledge.

  19. Dynamically generated gap from holography in the charged black brane with hyperscaling violation

    CERN Document Server

    Kuang, Xiao-Mei; Wang, Bin; Wu, Jian-Pin


    We holographically investigate the effects of a dipole coupling between a fermion field and a $U(1)$ gauge field on the dual fermionic sector in the charged gravity bulk with hyperscaling violation. We analytically study the features of the ultraviolet and infrared Green's functions of the dual fermionic system and we show that as the dipole coupling and the hyperscaling violation exponent are varied, the fluid possess Fermi, marginal Fermi, non-Fermi liquid phases and also an additional Mott insulating phase. We find that the increase of the hyperscaling violation exponent which effectively reduces the dimensionality of the system makes it harder for the Mott gap to be formed. We also show that the observed duality between zeros and poles in the presence of a dipole moment coupling still persists in theories with hyperscaling violation.

  20. Black Achievers' Experiences with Racial Spotlighting and Ignoring in a Predominantly White High School (United States)

    Carter Andrews, Dorinda J.


    Background/Context: Despite a history of racial oppression and degradation in U.S. schools, African Americans have responded to racism and discrimination in ways that promote educational attainment and school success. Many Black adolescents have been empowered to succeed academically partly because of their awareness of racist practices in…

  1. Black Hegemony, a Significant Influence in the School Success of High-Achieving African Americans. (United States)

    Murphy, Jean C.

    This is an interpretive study of the influence of Black Hegemony on the academic success of three successful African Americans: Clifton L. Taulbert, Henry Louis Gates, Jr., and Margaret Morgan Lawrence. All three spent their youth in southern communities strongly influenced by Jim Crow laws and customs, and their academic accomplishments were…

  2. The Role of Fathers in the Lives of Black Women of Achievement. (United States)

    Willie, Charles V.; Lane, Jolene A.


    Investigated fathers' roles in the lives of successful black women using life history case studies. Fathers were proud of and confident in their daughters, and most performed the role of mentor. Fathers gave daughters a sense of security that helped them succeed because they were not afraid to risk failure. Most fathers were interested in…

  3. Black Male College Achievers and Resistant Responses to Racist Stereotypes at Predominantly White Colleges and Universities (United States)

    Harper, Shaun R.


    In this article, Shaun R. Harper investigates how Black undergraduate men respond to and resist the internalization of racist stereotypes at predominantly White colleges and universities. Prior studies consistently show that racial stereotypes are commonplace on many campuses, that their effects are usually psychologically and academically…

  4. Does place explain racial health disparities? Quantifying the contribution of residential context to the Black/white health gap in the United States. (United States)

    Do, D Phuong; Finch, Brian Karl; Basurto-Davila, Ricardo; Bird, Chloe; Escarce, Jose; Lurie, Nicole


    The persistence of the black health disadvantage has been a puzzling component of health in the United States in spite of general declines in rates of morbidity and mortality over the past century. Studies that have focused on well-established individual-level determinants of health such as socio-economic status and health behaviors have been unable to fully explain these disparities. Recent research has begun to focus on other factors such as racism, discrimination, and segregation. Variation in neighborhood context-socio-demographic composition, social aspects, and built environment-has been postulated as an additional explanation for racial disparities, but few attempts have been made to quantify its overall contribution to the black/white health gap. This analysis is an attempt to generate an estimate of place effects on explaining health disparities by utilizing data from the U.S. National Health Interview Survey (NHIS) (1989-1994), combined with a methodology for identifying residents of the same blocks both within and across NHIS survey cross-sections. Our results indicate that controlling for a single point-in-time measure of residential context results in a roughly 15-76% reduction of the black/white disparities in self-rated health that were previously unaccounted for by individual-level controls. The contribution of residential context toward explaining the black/white self-rated health gap varies by both age and gender such that contextual explanations of disparities decline with age and appear to be smaller among females.

  5. Optimization of conditions to achieve high content of gamma amino butyric acid in germinated black rice, and changes in bioactivities

    Directory of Open Access Journals (Sweden)

    Chaiyavat CHAIYASUT

    Full Text Available Abstract The present study estimated the optimum germination conditions to achieve high content of Gamma-amino butyric acid (GABA and other phytochemicals in Thai black rice cultivar Kum Payao (BR. The Box–Behnken design of response surface methodology was employed to optimize the germination conditions. The changes in the GABA, phytochemical content, impact of salt, and temperature stress variation on phytochemical content, and stability of GABA were studied. The results showed that 12 h of soaking at pH 7, followed by 36 h of germination was the optimum condition to achieve maximum GABA content (0.2029 mg/g of germinated BR (GBR. The temperature (8 and 30 °C, and salt (50-200 mM NaCl content affected the phytochemicals of GBR, especially GABA, and anthocyanins. Obviously, the antioxidant capability, and enzyme (α-amylase and α-glucosidase inhibiting nature of BR was significantly (P < 0.001 increased after germination. The storage of GBR at 4 °C significantly, preserved the GABA content (∼80% for 45 days. Primarily, the current study revealed the changes in phytochemical content, and bioactivity of Thai black rice cr. Kum Payao during germination. More studies should be carried out on pharmacological benefits of GABA-rich GBR.

  6. Impact of Calendar on Student Achievement, Gender, and Ethnicity in Year-Round Schools


    Cary, Jennifer Michelle


    The achievement gap between Black and White students across the country continues to challenge school systems to rethink current initiatives and programs already in place. While the gap has narrowed since the late 1980s, advancement has been slow and minimal (Education Commission of the States, 2003). Present research has identified numerous factors that can be attributed to the achievement gap. While there is not one solution to closing the achievement gap, researchers indicate the need to r...

  7. Closing the science achievement gap for ninth grade English learners through standards- and inquiry-based science instruction (United States)

    Estrada, Myrna Hipol

    In light of the need to close the achievement gap among our culturally and linguistically diverse students, more specifically the Hispanics and the Hispanic English Learners (ELs), the effects of teacher professional development (2 year PD vs. 1 Year PD vs. no PD) on the implementation of a standards-aligned and inquiry-based science curriculum program---the Integrated Coordinated Science for the 21st Century published by It's About Time, Inc. (ICS-IAT)---on the LAUSD ninth graders science scores were examined. Participants included 8,937 9th grade students (7,356 Hispanics). The primary outcome measurement was scaled scores from the California Standard Test (CST) in Integrated Coordinated Science (CST_ICS1). Correlations between California English Language Development Test (CELDT) component subscores (reading, listening and speaking) and CST scores were also examined. Results indicated that the science scores of the students of teachers who participated in two year PD were significantly higher compared to the scores of students of the one year PD group and the control group. The results show that all ethnic groups benefited from two years of teacher PD, except the African American group. Among Hispanics, students classified as IFEP, RFEP and EO gained from the teachers having two years of professional development. But the target population, ELs did not benefit from two years of teacher PD. The correlations between the CELDT and CST_ELA were much higher than the CELDT and CST_ICS1 correlations. This finding validates Abedi's claim (2004) that EL students are disadvantaged because of their language handicap on tests that have a greater language load. Two year PD participation significantly enhanced the accessibility of science to the ninth graders. The essential features in the PD were classroom simulation of all the activities identified in the storyboard with the actual and correct use of needed equipment and materials; creation and presentation of sample or model

  8. Black Phosphorus Based Field Effect Transistors with Simultaneously Achieved Near Ideal Subthreshold Swing and High Hole Mobility at Room Temperature. (United States)

    Liu, Xinke; Ang, Kah-Wee; Yu, Wenjie; He, Jiazhu; Feng, Xuewei; Liu, Qiang; Jiang, He; Dan Tang; Wen, Jiao; Lu, Youming; Liu, Wenjun; Cao, Peijiang; Han, Shun; Wu, Jing; Liu, Wenjun; Wang, Xi; Zhu, Deliang; He, Zhubing


    Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm(2)/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

  9. Relationship of sex, achievement, and science self-concept to the science career preferences of black students (United States)

    Jacobowitz, Tina

    Science career preferences of junior high school-aged students, while not stable predictors of ultimate career choice, do serve to direct and maintain individuals along the paths to careers in science. In this study, factors relevant to science career preferences of black eighth grade students were investigated. This issue is of particular import to blacks since they are severely underrepresented in the scientific fields. The sample consisted of 113 males and 148 females in an inner city junior high school. The Science Career Preference Scale, the Peabody Picture Vocabulary Test, and the Self-Concept of Ability Scale (Form B-Science) were administered. Mathematics and science grades were obtained from class rating sheets. Treatment of the data involved multiple regression analysis according to a hierarchical model. Results showed that of all the independent variables, sex was the strongest predictor of science career preferences, accounting for 25% of the criterion variance. The findings suggest that early adolescent science career preferences are related more to interests that are consonant with sex-role considerations than realistic assessment of mathematics or science achievement.

  10. A Plan to Close the Achievement Gap for African American Students. Final Report. Submitted by the HB2722 Advisory Committee (United States)

    Washington Office of Superintendent of Public Instruction, 2008


    In 2008, the Washington State Legislature passed HB 2722, which called for the appointment of an Advisory Committee charged with creating a plan--which, when fully implemented, will close the education gap for African American students. Beginning in May 2008, the newly appointed HB 2722 Advisory Committee took on this challenging charge. Early in…

  11. Widening gap in age at muscular dystrophy-associated death between blacks and whites, 1986-2005. (United States)

    Kenneson, Aileen; Vatave, Ajay; Finkel, Richard


    Muscular dystrophies (MDs), characterized by progressive muscle wasting, are associated with 1 in 2,500 deaths in the United States. Although treatments slow the progression, these disorders lead to early death, usually due to cardiac or respiratory failure. We analyzed death record data from 18,315 MD-associated deaths that occurred in the United States in 1986 through 2005 to assess trends in the age at death of people with MDs. From 1986 through 2005, the MD-associated mortality rate did not change among blacks, whites, males, or females. The median age at death among white females with MDs was 12 years higher than among black females. The frequency of reported cardiomyopathy increased among white but not black male decedents with MDs, although cardiomyopathy remained more commonly reported among black males. Among white males, the median age at death increased by 0.2 annually for those with and 1.3 for those without indications of cardiomyopathy. Among black males, the median age at death increased 0.3 years annually among those without reported cardiomyopathy. Among white males, the frequencies of pulmonary failure and pulmonary infection decreased significantly over time. Changes in age at death and reported clinical comorbidities reflect improvements in the treatment of MDs. White males with MDs have shown a greater increase in age at death over time than black males. Contributing factors to this difference might include differences in types of MDs, rates of genetic and environmental modifiers, natural history, socioeconomic factors, and access to and use of treatment options.

  12. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander


    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...... suggested that appreciation of the highly personal motives of both Siouxsie Sioux and Janelle Monáe in wearing black may be achieved via analogies with the minimalist sublime of American artists Frank Stella’s and Ad Reinhardt’s black canvasses.......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 hinted by Rudyard Kipling’s illustration of ‘The [Black] Cat That Walked by Himself’ in his classic children’s tale). It was well understood by uniformed Anarchists, Fascists and the SS that there is an assertive presence connected with the black-clad figure. The paradox of black’s abstract elegance...

  13. Optimizing the configuration of a superconducting photonic band gap accelerator cavity to increase the maximum achievable gradients

    Directory of Open Access Journals (Sweden)

    Evgenya I. Simakov


    Full Text Available We present a design of a superconducting rf photonic band gap (SRF PBG accelerator cell with specially shaped rods in order to reduce peak surface magnetic fields and improve the effectiveness of the PBG structure for suppression of higher order modes (HOMs. The ability of PBG structures to suppress long-range wakefields is especially beneficial for superconducting electron accelerators for high power free-electron lasers (FELs, which are designed to provide high current continuous duty electron beams. Using PBG structures to reduce the prominent beam-breakup phenomena due to HOMs will allow significantly increased beam-breakup thresholds. As a result, there will be possibilities for increasing the operation frequency of SRF accelerators and for the development of novel compact high-current accelerator modules for the FELs.

  14. A Two Decade Examination of Historical Race/Ethnicity Disparities in Academic Achievement by Poverty Status. (United States)

    Paschall, Katherine W; Gershoff, Elizabeth T; Kuhfeld, Megan


    Research on achievement gaps by race/ethnicity and poverty status typically focuses on each gap separately, and recent syntheses suggest the poverty gap is growing while racial/ethnic gaps are narrowing. In this study, we used time-varying effect modeling to examine the interaction of race/ethnicity and poverty gaps in math and reading achievement from 1986-2005 for poor and non-poor White, Black, and Hispanic students in three age groups (5-6, 9-10, and 13-14). We found that across this twenty-year period, the gaps between poor White students and their poor Black and Hispanic peers grew, while the gap between non-poor Whites and Hispanics narrowed. We conclude that understanding the nature of achievement gaps requires simultaneous examination of race/ethnicity and income.

  15. Falling through the Cracks: Black Girls and Education (United States)

    Ricks, Shawn Arango


    The needs of Black girls are often overlooked by teachers, administrators, and policy makers. This oversight has contributed to a lack of educational programming and policies that address the impact of the intersection of racism and sexism on the educational experiences of Black girls, with some attention to the achievement gap. Policies simply…

  16. Too Much Is as Bad as Too Little? Sources of the Intention-Achievement Gap in Sustainable Innovation

    Directory of Open Access Journals (Sweden)

    Daegyu Yang


    Full Text Available Prior work on innovation has generally emphasized the importance of an organization’s exposure to external knowledge. This study, in contrast, redirects our attention toward conditions under which such exposure serves as constraints on organizational endeavors to achieve environmentally preferable innovation. We develop a two-stage model for sustainable innovation. A firm in the first stage explores a variety of alternatives and develops strategic intentions to address broader environmental concerns; thus, it may benefit from access to both diverse sources of external knowledge and network ties that enable an extensive search for new information. In the second stage, a firm exploits limited available options to achieve its strategic intentions. We suggest that dependence on external knowledge in the first stage makes the transition toward the second stage challenging, thereby reducing the probability that a firm’s strategic intentions for sustainability result in actual innovation outcomes. We test our theory using the 2014 Korean Innovation Survey. Our results show that diverse sources of external knowledge through rich network ties, albeit the positive main effects on innovation outcomes, negatively moderate the relationship between a firm’s intentions for environmental sustainability and its achievement of sustainable innovation. Several theoretical and practical implications are discussed.

  17. Expectancy and Achievement Gaps in Educational Attainment and Subsequent Adverse Health Effects Among Adolescents With and Without Chronic Medical Conditions. (United States)

    Wisk, Lauren E; Weitzman, Elissa R


    While education-based disparities in health are common, the extent to which chronic conditions contribute to education gaps and to consequent health disparities is not fully understood. As such, we sought to investigate educational aspirations, expectations, and attainment among youth with and without chronic conditions and to determine if these relationships mediated subsequent disparities in health and well-being. Longitudinal data on 3,518 youths are from the 1997-2013 Panel Study of Income Dynamics, a population-based survey. Multivariate regression was used to assess disparities in educational aspirations, expectations, and attainment by chronic conditions and the subsequent effects on health and well-being, adjusting for important potential confounders. Youth with chronic medical conditions (YCMCs) did not report significantly lower educational aspirations than their healthy peers; however, YCMC reported lower expectations for their educational attainment and fewer YCMC had earned their desired degree by the end of follow-up (e.g., ≥bachelor's degree: 19.9% for YCMC vs. 26.0% for peers, p educational attainment. Findings suggest an important risk mechanism through which YCMC may acquire socioeconomic disadvantage as they develop and progress through educational settings. Disproportionate lags in education, from expectation to attainment, may in turn increase YCMC's susceptibility to poor health and well-being in the future. Copyright © 2017 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  18. Interpreting the Early Language Trajectories of Children from Low SES and Language Minority Homes: Implications for Closing Achievement Gaps (United States)

    Hoff, Erika


    On average, children from low SES homes and children from homes in which a language other than English is spoken have different language development trajectories than children from middle class, monolingual English-speaking homes. Children from low SES and language minority homes have unique linguistic strengths, but many reach school age with lower levels of English language skill than middle class, monolingual children. Because early differences in English oral language skill have consequences for academic achievement, low levels of English language skill constitute a deficit for children about to enter school in the U.S. Declaring all developmental trajectories to be equally valid would not change the robust relation between English oral language skills and academic achievement and would not help children with poor English skills to be successful in school. Remedies aimed at supporting the development of the English skills required for academic success need not and should not entail devaluing or diminishing children’s other language skills. PMID:22329382

  19. Closing the social-class achievement gap: a difference-education intervention improves first-generation students' academic performance and all students' college transition. (United States)

    Stephens, Nicole M; Hamedani, MarYam G; Destin, Mesmin


    College students who do not have parents with 4-year degrees (first-generation students) earn lower grades and encounter more obstacles to success than do students who have at least one parent with a 4-year degree (continuing-generation students). In the study reported here, we tested a novel intervention designed to reduce this social-class achievement gap with a randomized controlled trial (N = 168). Using senior college students' real-life stories, we conducted a difference-education intervention with incoming students about how their diverse backgrounds can shape what they experience in college. Compared with a standard intervention that provided similar stories of college adjustment without highlighting students' different backgrounds, the difference-education intervention eliminated the social-class achievement gap by increasing first-generation students' tendency to seek out college resources (e.g., meeting with professors) and, in turn, improving their end-of-year grade point averages. The difference-education intervention also improved the college transition for all students on numerous psychosocial outcomes (e.g., mental health and engagement).

  20. Racial Microaggressions: The Schooling Experiences of Black Middle-Class Males in Arizona’s Secondary Schools

    Directory of Open Access Journals (Sweden)

    Quaylan Allen


    Full Text Available The literature on Black education has often neglected significant analysis of life in schools and the experience of racism among Black middle-class students in general and Black middle-class males specifically. Moreover, the achievement gap between this population and their White counterparts in many cases is greater than the gap that exists among working-class Blacks and Whites. This study begins to document the aforementioned by illuminating the racial microaggressions experienced by Black middle-class males while in school and how their families’ usage of social and cultural capital deflect the potential negative outcomes of school racism.

  1. Race and Color: Revisiting Perspectives in Black Education (United States)

    Monroe, Carla R.


    Racial inequities, such as systematic disparities in school discipline and achievement outcomes, are a perennial characteristic of public education in the United States. Although attention to interracial chasms such as the Black-White achievement gap is common, limited efforts are devoted to understanding how and why colorism motivates imbalances…

  2. Income Segregation between School Districts and Inequality in Students' Achievement (United States)

    Owens, Ann


    Large achievement gaps exist between high- and low-income students and between black and white students. This article explores one explanation for such gaps: income segregation between school districts, which creates inequality in the economic and social resources available in advantaged and disadvantaged students' school contexts. Drawing on…

  3. Crimea and the quest for energy and military hegemony in the Black Sea region: governance gap in a contested geostrategic zone

    NARCIS (Netherlands)

    Blockmans, S.


    Russia’s annexation of Crimea and its destabilization of Eastern Ukraine have radically altered the European security order, with the Black Sea region becoming an acutely contested geostrategic zone. Russia’s strategic interests in the Black Sea region, especially in terms of energy and military

  4. Closing the Achievement Gap by Improving Reading Instruction. Hearing before the Committee on Education and the Workforce. House of Representatives, One Hundred Seventh Congress, First Session (Orlando, Florida, November 13, 2001). (United States)

    Congress of the U.S., Washington, DC. House Committee on Education and the Workforce.

    A field hearing of the United States House of Representatives' Committee on Education and the Workforce, entitled "Closing the Achievement Gap by Improving Reading Instruction," was held at Lancaster Elementary School in Orlando, Florida, on November 13, 2001. The hearing begins with welcoming statements by the committee chairman and one…

  5. WWC Review of the Report "Closing the Social-Class Achievement Gap: A Difference-Education Intervention Improves First-Generation Students' Academic Performance and All Students' College Transition." What Works Clearinghouse Single Study Review (United States)

    What Works Clearinghouse, 2014


    For the 2014 study, "Closing the Social-Class Achievement Gap: A Difference-Education Intervention Improves First-Generation Students' Academic Performance and All Students' College Transition," researchers investigated the impact of attending a moderated panel on incoming freshmen's adjustment to college. The panel featured…

  6. Behind the Pay Gap (United States)

    Dey, Judy Goldberg; Hill, Catherine


    Women have made remarkable gains in education during the past three decades, yet these achievements have resulted in only modest improvements in pay equity. The gender pay gap has become a fixture of the U.S. workplace and is so ubiquitous that many simply view it as normal. "Behind the Pay Gap" examines the gender pay gap for college graduates.…

  7. Trends in Achievement Gaps in First-Year College Courses for Racial/Ethnic, Income, and Gender Subgroups: A 12-Year Study. ACT Research Report Series 2013 (8) (United States)

    Lorah, Julie; Ndum, Edwin


    Prior research has demonstrated gaps in the academic success of college student subgroups defined by race/ethnicity, income, and gender. We studied trends over time in the success of students in these subgroups in particular first-year college courses: English Composition I, College Algebra, social science courses, and Biology. The study is based…

  8. The neglected role of adolescent emotional well-being in national educational achievement: bridging the gap between education and mental health policies. (United States)

    Sznitman, Sharon R; Reisel, Liza; Romer, Daniel


    Although child poverty is recognized as a critical determinant of poor educational achievement in the United States, policy discussions on raising academic achievement rarely include the importance of the effects of poverty on the mental health of adolescents. This article examines the role of adolescent emotional well-being (indicators of depression) as a mediator of the effects of poverty on differences in educational achievement at the national and U.S. state levels. Differences in standardized adolescent academic achievement across 23 developed countries and 39 U.S. states were analyzed using path analytic techniques to test the hypothesis that indicators of adolescent emotional well-being mediate relations between child poverty rates and academic achievement. Child poverty rates were related to both adolescent emotional well-being and educational achievement across both U.S. states and developed countries. Path analyses showed that the status of a country's or state's adolescent emotional well-being is a strong predictor of its educational achievement and that emotional well-being mediates the relationship between poverty and educational achievement. Policies designed to ameliorate the adverse effects of poverty on mental health are critical as they are likely to improve both average educational achievement and student emotional well-being. Attention to improving mental health care not only has the potential to reduce societal and individual costs directly related to health but also to reduce the indirect costs of poor educational achievement. Copyright © 2011 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  9. A strategy to achieve enhanced electromagnetic interference shielding at low concentration with a new generation of conductive carbon black in a chlorinated polyethylene elastomeric matrix. (United States)

    Mondal, Subhadip; Ganguly, Sayan; Rahaman, Mostafizur; Aldalbahi, Ali; Chaki, Tapan K; Khastgir, Dipak; Das, Narayan Ch


    The fabrication of scalable and affordable conductive Ketjen carbon black (K-CB)-elastomer composites for adjustable electromagnetic interference (EMI) shielding remains a difficult challenge. Herein, chlorinated polyethylene (CPE)-K-CB composites have been developed by single step solution mixing to achieve high EMI shielding performance associated with absorption dominance potency by conductive dissipation as well as the reflection of electromagnetic waves. The dispersion of K-CB inside the CPE matrix has been corroborated by electron micrographs and atomic force microscopy (AFM). The K-CB filler and CPE polymer interaction has been investigated through the bound rubber content (Bdr) and the dynamic mechanical properties. The relatively low loading of K-CB with respect to other conventional carbon fillers contributes to a promising low percolation threshold (9.6 wt% K-CB) and a reasonably high EMI shielding effectiveness (EMI SE) value of 38.4 dB (at 30 wt% loading) in the X-band region (8.2 to 12.4 GHz). Classical percolation theory reveals that the electrical conduction behavior through the composite system is quasi-two dimensional in nature. Our belief lies in the promotion of scalable production of flexible and cost-effective K-CB-CPE composites of superior EMI SE to avoid electromagnetic radiation pollution.

  10. Invited article summarizing the Science To Achieve Results research portfolio on Black Carbon for the journal EM of the Air and Waste Management Association. (United States)

    Where there’s smoke, there’s fire – and black carbon. Black carbon is the sooty material emitted from combustion processes, including diesel engines and other sources that burn fossil fuels, biofuels, or biomass. This soot contributes to fine particulate matter,...

  11. Friend Effects and Racial Disparities in Academic Achievement

    Directory of Open Access Journals (Sweden)

    Jennifer Flashman


    Full Text Available Racial disparities in achievement are a persistent fact of the US educational system. An often cited but rarely directly studied explanation for these disparities is that adolescents from different racial and ethnic backgrounds are exposed to different peers and have different friends. In this article I identify the impact of friends on racial and ethnic achievement disparities. Using data from Add Health and an instrumental variable approach, I show that the achievement characteristics of youths’ friends drive friend effects; adolescents with friends with higher grades are more likely to increase their grades compared to those with lower-achieving friends. Although these effects do not differ across race/ethnicity, given differences in friendship patterns, if black and Latino adolescents had friends with the achievement characteristics of white students, the GPA gap would be 17 to 19 percent smaller. Although modest, this effect represents an important and often overlooked source of difference among black and Latino youth.

  12. Closing the health and nutrition gap in Odisha, India: A case study of how transforming the health system is achieving greater equity. (United States)

    Thomas, Deborah; Sarangi, Biraj Laxmi; Garg, Anu; Ahuja, Arti; Meherda, Pramod; Karthikeyan, Sujata R; Joddar, Pinaki; Kar, Rajendra; Pattnaik, Jeetendra; Druvasula, Ramesh; Dembo Rath, Alison


    Health equity is high on the international agenda. This study provides evidence of how health systems can be strengthened to improve health equity in a low-income state. The paper presents a case study of how the Government of Odisha in eastern India is transforming the health system for more equitable health and nutrition outcomes. Odisha has a population of over 42 million, high levels of poverty, and poor maternal and child health concentrated in its Southern districts and among Scheduled Tribe and Scheduled Caste communities. Conducted between 2008 and 2012 with the Departments of Health and Family Welfare, and Women and Child Development, the study reviewed a wide range of literature including policy and programme documents, evaluations and studies, published and grey material, and undertook secondary analysis of state level household surveys. It identifies innovative and expanded provision of health services, reforms to the management and development of human resources for health, and the introduction of a number of cash transfer and entitlement schemes as contributing to closing the gap between maternal and child health and nutrition outcomes of Scheduled Tribes, and the Southern districts, compared to the state average. The institutional delivery rate for Scheduled Tribes has risen from 11.7% in 2005-06 to 67.3% in 2011, and from 35.6% to 79.8% for all women. The social gradient has also closed for antenatal and postnatal care and immunisation. Nutrition indicators though improving are proving slower to budge. The paper identifies how political will, committed policy makers and fiscal space energised the health system to promote equity. Sustained political commitment will be required to continue to address the more challenging human resource, health financing and gender issues. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  13. Why the racial gap in life expectancy is declining in the United States

    Directory of Open Access Journals (Sweden)

    Glenn Firebaugh


    Full Text Available Background: Blacks have lower life expectancy than whites in the United States. That disparity could be due to racial differences in the causes of death, with blacks being more likely to die of causes that affect the young, or it could be due to differences in the average ages of blacks and whites who die of the same cause. Prior studies fail to distinguish these two possibilities. Objective: In this study we determine how much of the 2000-10 reduction in the racial gap in life expectancy resulted from narrowing differences in the cause-specific mean age at death for blacks and whites, as opposed to changing cause-specific probabilities for blacks and whites. Methods: We introduce a method for separating the difference-in-probabilities and difference-in-age components of group disparities in life expectancy. Results: Based on the new method, we find that 60Š of the decline in the racial gap in life expectancy from 2000 to 2010 was attributable to reduction in the age component, largely because of declining differences in the age at which blacks and whites die of chronic diseases. Conclusions: Our findings shed light on the sources of the declining racial gap in life expectancy in the United States, and help to identify where advances need to be made to achieve the goal of eliminating racial disparities in life expectancy.

  14. Black men in the medical education pipeline: past, present, and future. (United States)

    Ready, T; Nickens, H W


    The authors discuss the decline in the numbers of black men enrolling in medical school over the last two decades and assess possible reasons for it, including the smaller numbers of men from nearly all races and ethnic groups now applying to medical school, the declining popularity of the undergraduate biology degree among men in general, the falling number of black students who go on to college, and, underlying all these, the pervasive effects of poverty on educational achievement, the dwindling employment opportunities for black men of limited education (brought on by dramatic changes in the American economy), and the rising indices of stress and alienation among black men. The authors review the larger social implications of the growing educational gap between black men and other segments of society, pose questions about some of the trends that have been mentioned, indicate lines for further research, and propose potential solutions to the problem of the deepening underrepresentation of black men in medical schools.

  15. Karl Marx, Ludwig Wittgenstein, and Black Underachievement in the United States and United Kingdom (United States)

    Tomlin, Carol; Wright, Cecile; Mocombe, Paul C.


    This article synthesizes Marxian conceptions of identity construction within capitalist relations of production with the Wittgensteinian notion of "language games" to offer a more appropriate relational framework within which scholars ought to understand the Black-White academic achievement gap in America, the United Kingdom, and…

  16. Beyond Black and White: The Model Minority Myth and the Invisibility of Asian American Students (United States)

    Wing, Jean Yonemura


    This study of diverse Asian American students at a racially integrated public high school illustrates that the achievement gap is a multi-racial problem that cannot be well understood solely in terms of the trajectories of Black and white students. Asian American students demonstrated a high academic profile on average, but faced difficulties and…

  17. The Piney Woods School: An Exploration of the Historically Black Boarding School Experience in Shaping Student Achievement, Cultural Esteem, and Collegiate Integration (United States)

    Alexander-Snow, Mia


    This qualitative case study explores the cultural impact the Piney Woods School, a historically Black independent boarding school, had on the social and academic experiences of four of its graduates in attendance at two traditionally White universities. The article discusses the collegiate experiences of four students: Samantha, Ira, Tony, and…

  18. The Gap Within the Gap

    Directory of Open Access Journals (Sweden)

    Katherine Michelmore


    Full Text Available Gaps in educational achievement between high- and low-income children are growing. Administrative data sets maintained by states and districts lack information about income but do indicate whether a student is eligible for subsidized school meals. We leverage the longitudinal structure of these data sets to develop a new measure of economic disadvantage. Half of eighth graders in Michigan are eligible for a subsidized meal, but just 14% have been eligible for subsidized meals in every grade since kindergarten. These children score 0.94 standard deviations below those who are never eligible for meal subsidies and 0.23 below those who are occasionally eligible. There is a negative, linear relationship between grades spent in economic disadvantage and eighth-grade test scores. This is not an exposure effect; the relationship is almost identical in third-grade, before children have been exposed to varying years of economic disadvantage. Survey data show that the number of years that a child will spend eligible for subsidized lunch is negatively correlated with her or his current household income. Years eligible for subsidized meals can therefore be used as a reasonable proxy for income. Our proposed measure can be used to estimate heterogeneous effects in program evaluations, to improve value-added calculations, and to better target resources.

  19. Exploration of Factors Affecting Success of Undergraduate Engineering Majors at a Historically Black University (United States)

    Igbinoba, Egheosa P.

    Blacks are underrepresented amongst persons who earn college degrees in the United States and Black males attend and complete college at a lower rate than Black females (Toldson, Fry Brown, & Sutton, 2009). According to Toldson et al. (2009), this quandary may be attributed to Black males' apathy toward education in general, waning support and ideological challenges toward Pell Grants and affirmative action, cultural incompetency on the part of the 90% White, ethnic makeup of the U.S. teaching force, and the relatively high numbers of Black males who are held back in school. In spite of the dismal statistics regarding Black male academic achievement and matriculation, there are those Black males who do participate in postsecondary education. While many studies have highlighted reasons that Black males do not achieve success in attending and persisting through college, few have adopted the anti-deficit research framework suggested by Harper (2010), identifying reasons Black males do persist in higher education. Although science, technology, engineering, and mathematics careers are identified as those most imperative to the economic competitiveness of the United States, few studies have concentrated solely on engineering majors and fewer, if any, solely on Black male engineering majors at an historically Black college and university. The aim of this study was to address an apparent gap in the literature and invoke theories for recruitment, retention, and success of Black males in engineering degree programs by employing an anti-deficit achievement framework for research of students of color in science, technology, engineering, and mathematics. Data garnered from the study included insight into participants' definitions of success, precollege experiences, factors contributing to the persistence during undergraduate study, and perceptions of attending a historically Black college and university versus a primarily White institution.

  20. Knowledge Gaps

    DEFF Research Database (Denmark)

    Lyles, Marjorie; Pedersen, Torben; Petersen, Bent


    , assimilating, and utilizing knowledge - are crucial determinants ofknowledge gap elimination. In contrast, the two factors deemed essential in traditionalinternationalization process theory - elapsed time of operations and experientiallearning - are found to have no or limited effect.Key words......: Internationalization, knowledge gap, absorptive capacity, learning box....

  1. Black Musicians Leading the Way. (United States)

    Music Educators Journal, 1982


    Describes the careers and musical achievements of Blacks who were forerunners in jazz, blues, gospel, music, spirituals, band music, classical music, ragtime, and opera. The list was compiled to provide teachers with historical background information for "Black History Month." (AM)

  2. Gap Resolution

    Energy Technology Data Exchange (ETDEWEB)


    Gap Resolution is a software package that was developed to improve Newbler genome assemblies by automating the closure of sequence gaps caused by repetitive regions in the DNA. This is done by performing the follow steps:1) Identify and distribute the data for each gap in sub-projects. 2) Assemble the data associated with each sub-project using a secondary assembler, such as Newbler or PGA. 3) Determine if any gaps are closed after reassembly, and either design fakes (consensus of closed gap) for those that closed or lab experiments for those that require additional data. The software requires as input a genome assembly produce by the Newbler assembler provided by Roche and 454 data containing paired-end reads.

  3. Gap junctions. (United States)

    Goodenough, Daniel A; Paul, David L


    Gap junctions are aggregates of intercellular channels that permit direct cell-cell transfer of ions and small molecules. Initially described as low-resistance ion pathways joining excitable cells (nerve and muscle), gap junctions are found joining virtually all cells in solid tissues. Their long evolutionary history has permitted adaptation of gap-junctional intercellular communication to a variety of functions, with multiple regulatory mechanisms. Gap-junctional channels are composed of hexamers of medium-sized families of integral proteins: connexins in chordates and innexins in precordates. The functions of gap junctions have been explored by studying mutations in flies, worms, and humans, and targeted gene disruption in mice. These studies have revealed a wide diversity of function in tissue and organ biology.

  4. Closing the achievement gap through modification of neurocognitive and neuroendocrine function: results from a cluster randomized controlled trial of an innovative approach to the education of children in kindergarten.

    Directory of Open Access Journals (Sweden)

    Clancy Blair

    Full Text Available Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children's engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap.

  5. Closing the achievement gap through modification of neurocognitive and neuroendocrine function: results from a cluster randomized controlled trial of an innovative approach to the education of children in kindergarten. (United States)

    Blair, Clancy; Raver, C Cybele


    Effective early education is essential for academic achievement and positive life outcomes, particularly for children in poverty. Advances in neuroscience suggest that a focus on self-regulation in education can enhance children's engagement in learning and establish beneficial academic trajectories in the early elementary grades. Here, we experimentally evaluate an innovative approach to the education of children in kindergarten that embeds support for self-regulation, particularly executive functions, into literacy, mathematics, and science learning activities. Results from a cluster randomized controlled trial involving 29 schools, 79 classrooms, and 759 children indicated positive effects on executive functions, reasoning ability, the control of attention, and levels of salivary cortisol and alpha amylase. Results also demonstrated improvements in reading, vocabulary, and mathematics at the end of kindergarten that increased into the first grade. A number of effects were specific to high-poverty schools, suggesting that a focus on executive functions and associated aspects of self-regulation in early elementary education holds promise for closing the achievement gap.

  6. Black Craftsmen Through History. (United States)

    Myers, Robin

    This report traces the evolution of the black craftsmen from ancient Egypt to the present. Special attention is given to the restricted use of black craftsmen under slavery, and the added problems they faced after being freed. Business and union discimination is described, along with recent government and private efforts to achieve equal…

  7. The Idea Gap in Pink and Black


    Lisa D. Cook; Chaleampong Kongcharoen


    Previous studies have found large gender and racial differences in commercialization of invention. Using novel data that permit enhanced identification of women and African American inventors, we find that gender and racial differences in commercial activity related to invention are lower than once thought. This is despite relatively lower patent activity among women and African Americans. Further, among determinants of commercialization, the evidence suggests that advanced training in engine...

  8. African American Male College Students Navigate to Achieve: The Relationship among College Adjustment Experiences, Coping, and GPA for Black Males at Two Predominantly White Institutions (United States)

    Walters, Sabrina Denise


    African American males face daunting obstacles as they pursue higher education as research has shown. This study sought to better understand the impact of specific factors--social support, racial identity, perceived racial discrimination, coping, and religious coping--on the academic achievement of African American male college student…

  9. Black holes and quantum processes in them

    International Nuclear Information System (INIS)

    Frolov, V.P.


    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

  10. Black silicon integrated aperture (United States)

    Liu, Tianbo; Dickensheets, David L.


    This paper describes the incorporation of nanotextured black silicon as an optical absorbing material into silicon-based micro-optoelectromechanical systems devices to reduce stray light and increase optical contrast during imaging. Black silicon is created through a maskless dry etch process and characterized for two different etch conditions, a cold etch performed at 0°C and a cryogenic etch performed at -110°C. We measure specular reflection at visible wavelengths to be black velvet paint used to coat optical baffles and compare favorably with other methods to produce black surfaces from nanotextured silicon or using carbon nanotubes. We illustrate the use of this material by integrating a black silicon aperture around the perimeter of a deformable focus-control mirror. Imaging results show a significant improvement in contrast and image fidelity due to the effective reduction in stray light achieved with the self-aligned black aperture.

  11. Closing the Mathematical Achievement Gap Through the Heart To the Brain: A Case Study of Urban High School Mathematics Teachers' Perceptions of How Their Emotional Intelligence Facilitates Instruction and Learning in the Classroom (United States)

    Fang, Chung-Chieh

    The purpose of this qualitative case study was to examine urban high school mathematics teachers' perceptions of how they manage their own and their students' emotional intelligence (EI) to facilitate instruction and learning; their reports of how they handle their emotions as urban mathematics teachers; and their reports of how they manage the emotions of their students. The study focused on the voices of sixteen urban mathematics teachers and was undertaken in reaction to the significant mathematics achievement gap between urban students and their suburban counterparts. The conceptual framework undergirding the study was synthesized work by Daniel Goleman, (1995) and Mayer and Salovey (1997); categorizing emotional intelligence in emotional selfawareness, managing emotions, harnessing emotions, empathy, and handling relationships. Research questions addressing each category were created and from these categories an interview guide was developed. Data gathered during individual teacher interviews was transcribed and sorted into emergent categories using open coding. The findings were organized and presented according to the study's research questions. Urban math teachers reported passion for their students, their feelings affect teaching and learning, and that humor is an important tool in mediating emotions. The study concludes with multiple recommendations for further research and practices. Future studies should compare teachers assuming paternal vs. mentor role when dealing with their students. The study can evaluate if either role has a significant impact in student teacher relationships. A recommendation for practice is for teachers to have professional development experiences focusing on the proper use of humor in the classroom. Humor used properly promotes a positive classroom environment. This is a skill that would be especially beneficial to urban teachers.

  12. Black holes

    International Nuclear Information System (INIS)

    Feast, M.W.


    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

  13. How black holes saved relativity (United States)

    Prescod-Weinstein, Chanda


    While there have been many popular-science books on the historical and scientific legacy of Albert Einstein's general theory of relativity, a gap exists in the literature for a definitive, accessible history of the theory's most famous offshoot: black holes. In Black Hole, the science writer Marcia Bartusiak aims for a discursive middle ground, writing solely about black holes at a level suitable for both high-school students and more mature readers while also giving some broader scientific context for black-hole research.

  14. Black Alcoholism. (United States)

    Watts, Thomas D.; Wright, Roosevelt


    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)

  15. Black Culture (United States)

    Brown, Angela Khristin


    The migration of blacks in North America through slavery became united. The population of blacks passed down 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…

  16. Two-Dimensional Dirac Fermions Protected by Space-Time Inversion Symmetry in Black Phosphorus (United States)

    Kim, Jimin; Baik, Seung Su; Jung, Sung Won; Sohn, Yeongsup; Ryu, Sae Hee; Choi, Hyoung Joon; Yang, Bohm-Jung; Kim, Keun Su


    We report the realization of novel symmetry-protected Dirac fermions in a surface-doped two-dimensional (2D) semiconductor, black phosphorus. The widely tunable band gap of black phosphorus by the surface Stark effect is employed to achieve a surprisingly large band inversion up to ˜0.6 eV . High-resolution angle-resolved photoemission spectra directly reveal the pair creation of Dirac points and their movement along the axis of the glide-mirror symmetry. Unlike graphene, the Dirac point of black phosphorus is stable, as protected by space-time inversion symmetry, even in the presence of spin-orbit coupling. Our results establish black phosphorus in the inverted regime as a simple model system of 2D symmetry-protected (topological) Dirac semimetals, offering an unprecedented opportunity for the discovery of 2D Weyl semimetals.

  17. Black phosphorus-based one-dimensional photonic crystals and microcavities. (United States)

    Kriegel, Ilka; Toffanin, Stefano; Scotognella, Francesco


    The latest achievements in the fabrication of thin layers of black phosphorus (BP), toward the technological breakthrough of a phosphorene atomically thin layer, are paving the way for their use in electronics, optics, and optoelectronics. In this work, we have simulated the optical properties of one-dimensional photonic structures, i.e., photonic crystals and microcavities, in which few-layer BP is one of the components. The insertion of the 5-nm black phosphorous layers leads to a photonic band gap in the photonic crystals and a cavity mode in the microcavity that is interesting for light manipulation and emission enhancement.

  18. A Call for Scientifically-Rigorous, Community-Based "Actionable Intelligence" to Promote the Academic Achievement of African American Boys: An Introduction to Fantuzzo, LeBoeuf, Rouse, and Chen (2012) and Commentaries (United States)

    McWayne, Christine M.


    This introduction briefly summarizes the featured article and commentaries making up this commissioned set of papers on the topic of the Black-White achievement gap and, more specifically, risk and protective factors for young African American boys' school success. Each paper highlights important considerations for advancing scholarship, practice,…

  19. Being Black and Brown in the 21st Century

    Directory of Open Access Journals (Sweden)

    Pierre W. Orelus


    Full Text Available Depending on one’s level of understanding and awareness about the plight of Black and Brown people, one might argue that they are better off today than they were 50 years ago or so, especially when one remembers the Jim Crow era during which Black and Brown people were ruthlessly brutalized, particularly by White supremacist groups such as the Klu Klux Kan. However, if one critically analyzed the achievement gap between students of color and their White counterparts, the decline in incomes, and other forms of educational and socioeconomic inequality that Black and Brown people, particularly poor students of color, have been experiencing for the last several decades or so, one would realize that substantially nothing has changed for them. In light of this view, this article explores the educational and socioeconomic conditions of People of Color, including those of linguistically and culturally diverse students. Specifically, it examines the ways and the degree to which lack of resources combined with institutional racism and the legacy of slavery continue to limit the life chances of Black and Brown people in the 21st century. The author ends this article making recommendations to counter inequality in schools and society at large that Black and Brown people have been facing.

  20. Few-layer black phosphorus nanoparticles. (United States)

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


    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.

  1. Black hole entropy, curved space and monsters

    International Nuclear Information System (INIS)

    Hsu, Stephen D.H.; Reeb, David


    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

  2. Anaesthetic hazards of the 'passion gap'

    African Journals Online (AJOL)

    slaves imported by the Dutch East India Company from the. East, the early white settJers and, later, blacks. Within this population there are two small distinctive communities: the. Griquas and the Cape Malays.3,4. Why does the 'passion gap' exist among the Cape Coloureds? The popular belief is that the teeth are removed ...

  3. Adoptees' Educational Achievements

    DEFF Research Database (Denmark)

    Olsen, Rikke Fuglsang

    This study analyses educational achievement at age 20 for 3,180 non-kin adoptees and at age 25 for 1,559 non-kin adoptees in Denmark by comparing them to non-adoptees. The study also analyses whether there are within-group differences in the educational achievement of non-kin adoptees according...... to country of origin. The results suggest that the relatively small gap between non-kin adoptees’ and non-adoptees’ educational achievements widens between ages 20 and 25. Moreover, the results show some differences in educational outcomes among non-kin adoptees with different countries of origin....

  4. Therapeutic Dimensions of the Black Aesthetic (United States)

    Toldson, Ivory L.; Pasteur, Alfred B.


    The authors of this article see the black aesthetic largely in terms of the affective component. Emotional oneness which is foreign to the white world view is the means by which the black man can achieve optimal mental health and development. The therapeutic implications of the black aesthetic are outlined. (NG)

  5. The Racial School Climate Gap: Within-School Disparities in Students' Experiences of Safety, Support, and Connectedness. (United States)

    Voight, Adam; Hanson, Thomas; O'Malley, Meagan; Adekanye, Latifah


    This study used student and teacher survey data from over 400 middle schools in California to examine within-school racial disparities in students' experiences of school climate. It further examined the relationship between a school's racial climate gaps and achievement gaps and other school structures and norms that may help explain why some schools have larger or smaller racial disparities in student reports of climate than others. Multilevel regression results problematized the concept of a "school climate" by showing that, in an average middle school, Black and Hispanic students have less favorable experiences of safety, connectedness, relationships with adults, and opportunities for participation compared to White students. The results also show that certain racial school climate gaps vary in magnitude across middle schools, and in middle schools where these gaps are larger, the racial achievement gap is also larger. Finally, the socioeconomic status of students, student-teacher ratio, and geographic location help explain some cross-school variation in racial climate gaps. These findings have implications for how school climate in conceptualized, measured, and improved.

  6. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown


    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.

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


    Greene, Jenny E.


    This article documents our ongoing search for the elusive "intermediate-mass" black holes. These would bridge the gap between the approximately ten solar mass "stellar-mass" black holes that are the end-product of the life of a massive star, and the "supermassive" black holes with masses of millions to billions of solar masses found at the centers of massive galaxies. The discovery of black holes with intermediate mass is the key to understanding whether supermassive black holes can grow from...

  8. What Works Clearinghouse Quick Review: "Closing the Social-Class Achievement Gap: A Difference-Education Intervention Improves First-Generation Students' Academic Performance and All Students' College Transition" (United States)

    What Works Clearinghouse, 2014


    This study measured the impact of a difference-education intervention on the academic achievement of first generation college students. The difference-education intervention teaches students how their social class backgrounds can affect what they experience in college. Participants attended a moderated panel discussion featuring demographically…

  9. Low-mass black holes as the remnants of primordial black hole formation. (United States)

    Greene, Jenny E


    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.

  10. Black Cohosh (United States)

    ... who have had hormone-sensitive conditions such as breast cancer or for pregnant women or nursing mothers. Black cohosh should not be confused with blue cohosh (Caulophyllum thalictroides) , which has different effects and may not be safe. Black cohosh has ...

  11. Exploring racial differences in the obesity gender gap. (United States)

    Seamans, Marissa J; Robinson, Whitney R; Thorpe, Roland J; Cole, Stephen R; LaVeist, Thomas A


    To investigate whether the gender gap in obesity prevalence is greater among U.S. blacks than whites in a study designed to account for racial differences in socioeconomic and environmental conditions. We estimated age-adjusted, race-stratified gender gaps in obesity (% female obese - % male obese, defined as body mass index ≥30 kg/m(2)) in the National Health Interview Survey 2003 and the Exploring Health Disparities in Integrated Communities-Southwest Baltimore 2003 study (EHDIC-SWB). EHDIC-SWB is a population-based survey of 1381 adults living in two urban, low-income, racially integrated census tracts with no race difference in income. In the National Health Interview Survey, the obesity gender gap was larger in blacks than whites as follows: 7.7 percentage points (ppts; 95% confidence interval (CI): 3.4-11.9) in blacks versus -1.5 ppts (95% CI: -2.8 to -0.2) in whites. In EHDIC-SWB, the gender gap was similarly large for blacks and whites as follows: 15.3 ppts (95% CI: 8.6-22.0) in blacks versus 14.0 ppts (95% CI: 7.1-20.9) in whites. In a racially integrated, low-income urban community, gender gaps in obesity prevalence were similar for blacks and whites. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Public Perceptions of the Pay Gap (United States)

    Hill, Catherine; Silva, Elena


    Women have made gains toward closing the gender pay gap during the past two decades. Much of the progress occurred during the 1980s, with smaller gains in the 1990s (Institute for Women's Policy Research 2004). Women's achievements in higher education are partly responsible for narrowing the pay gap in the 1980s and 1990s. As more women earned…

  13. The renaissance of black phosphorus. (United States)

    Ling, Xi; Wang, Han; Huang, Shengxi; Xia, Fengnian; Dresselhaus, Mildred S


    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.


    International Nuclear Information System (INIS)



    During the RHIC Au-run in 2001 the 200 MHz storage cavity system was used for the first time. The rebucketing procedure caused significant beam debunching in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam could account for approximately 30%-40% of the total beam intensity. Some of it will be in the abort gap. In order to minimize the risk of magnet quenching due to uncontrolled beam losses at the time of a beam dump, a combination of a fast transverse kicker and copper collimators were used to clean the abort gap. This report gives an overview of the gap cleaning procedure and the achieved performance

  15. Black Tea (United States)

    ... leaves of the same plant, has some different properties. Black tea is used for improving mental alertness ... that slow blood clotting include aspirin, clopidogrel (Plavix), diclofenac (Voltaren, Cataflam, others), ibuprofen (Advil, Motrin, others), naproxen ( ...

  16. Charting service quality gaps


    Cândido, Carlos; Morris, D. S.


    Some of the most influential models in the service management literature (Parasuraman et al., 1985; Grönroos, 1990) focus on the concept of service quality gap (SQG). Parasuraman et al. (1985) define a pioneering model with five SQGs, the concepts of which are amplified in Brogowicz et al.’s (1990) model. The latter has five types of encompassing gaps: information and feedback-related gaps; design-related gaps; implementation-related gaps; communication-related gaps; and customers’ perception...

  17. Defense economics: Achievements and challenges


    Keith Hartley


    Defense economics is now an established part of economics. This article reviews its achievements as represented by papers published in the research journal Defense and Peace Economics. The range of topics in the journal is reviewed, especially since 2000, and major gaps in coverage are identified. A changing research agenda reflects new developments such as terrorism and international peacekeeping. Gaps remain such as the need for good quality case studies of conflict (e.g., Iraq) and of majo...

  18. Beyond the black hole

    International Nuclear Information System (INIS)

    Boslough, J.


    This book is about the life and work of Stephen Hawking. It traces the development of his theories about the universe and particularly black holes, in a biographical context. Hawking's lecture 'Is the end in sight for theoretical physics' is presented as an appendix. In this, he discusses the possibility of achieving a complete, consistent and unified theory of the physical interactions which would describe all possible observations. (U.K.)

  19. Public Library Summer Reading Programs Contribute to Reading Progress and Proficiency. A Review of: Roman, S., & Fiore, C. (2010. Do public library summer reading programs close the achievement gap? Children and Libraries, (Winter, 27-31.

    Directory of Open Access Journals (Sweden)

    Gayle Bogel


    Full Text Available Objectives – To explore summer reading partnerships between public libraries and school libraries, and the impact on student achievement in reading.Design – The design is mixed methods: tests, interviews and surveys.Setting – Eleven US sites involving school and public library partners.Subjects – A total of 357 elementary school students entering fourth grade that met specific criteria. Parents, teachers, school librarians and public librarians were also included.Methods – This study occurred over a three year period from 2006-2009. It was developed as a partnership between Dominican University, the Colorado State Library Agency and the Texas Library and Archives Commission. Additionally, the Center for Summer Learning at Johns Hopkins University was contracted to conduct the research. It was designed to explore the research question central to a 1978 study by Barbara Heyns.An advisory committee, with representatives from each partner agency, developed evaluation questions and established the objective selection criteria for participants in the study. The criteria included: at least 50% of students qualifying for free and reduced price meals; at least 85 percent of school population would take the reading proficiency test in English; public library summer reading programs with a minimum of six weeks of programming; a history of collaboration between the paired school and public library applicants; both school and public library would sign a partnership agreement and participate in conference calls.In spring of 2008, students at participating sites were given a pre-test using the Scholastic Reading Inventory, and also provided with special summer reading logs developed for the study, to be used during their subsequent participation in the public library summer reading programs.In fall of 2008, the same children were tested on the Scholastic Reading Inventory. In addition, surveys of students, parents, teachers and library staff were

  20. Mathematics Achievement by Immigrant Children

    Directory of Open Access Journals (Sweden)

    Gary G. Huang


    Full Text Available In this study, I examined academic achievement of immigrant children in the United States, Canada, England, Australia, and New Zealand. Analyzing data from the Third International Mathematics and Science Study (TIMSS, I gauged the performance gaps relating to the generation of immigration and the home language background. I found immigrant children's math and science achievement to be lower than the others only in England, the U.S., and Canada. Non-English language background was found in each country to relate to poor math and science learning and this disadvantage was stronger among native-born children—presumably children of indigenous groups—than among immigrant children. I also examined the school variation in math performance gaps, using hierarchical linear modeling (HLM to each country's data. The patterns in which language- and generation-related math achievement gaps varied between schools are different in the five countries.

  1. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)



    instance, the UK's research councils have yet to put any real money behind these ideas. Black holes are best described by the general theory of relativity. However, general relativity is a classical theory of gravity, and although its predictions have been verified in many experiments, a quantum theory of gravity remains one of the holy grails of physics. One of the first physicists to make real progress in this quest to reconcile general relativity and quantum mechanics was Stephen Hawking. In 1974 Hawking calculated what would happen if a quantum fluctuation occurred near an event horizon. He concluded that the black hole would radiate, and that the amount of radiation would be inversely proportional to the mass of the black hole. However, black holes tend to be very heavy, so their output of Hawking radiation would be too low to detect experimentally. One intriguing exception could be much smaller primordial black holes created in the big bang: these should radiate observable amounts of gamma rays, but they have not been detected yet. This whole body of work - in which thermodynamic concepts such as temperature and entropy are also associated with the black hole - is Hawking's major achievement in physics. The detection of Hawking radiation is the ultimate goal of experiments on artificial black holes, although a lot of theoretical and experimental work has to be done first. The successful experiment is likely to involve a flowing Bose-Einstein condensate or a medium in which the speed of light can be reduced to zero. After years of groundwork, physicists have recently made rapid progress in both these fields. Meanwhile, the recent observation of neutrons in discrete quantum states in a gravitational potential shows that quantum gravity effects can be seen in the laboratory. All that is needed now is an act of faith. (U.K.)

  2. Trends in Education Excellence Gaps: A 12-Year International Perspective via the Multilevel Model for Change (United States)

    Rutkowski, David; Rutkowski, Leslie; Plucker, Jonathan A.


    A recent study in the USA documented the existence and growth of "excellence gaps" among students. These gaps are similar to the minimum competency achievement gaps that proliferate in policy discussions in many Western countries, but excellence gaps focus on the highest level of achievement rather than minimum competency. We extend this…

  3. Black Willow (United States)

    R. M. Krinard


    Black willow and other species of Salix together comprise a majority of the stocking. Cottonwood is the chief associate, particularly in the early stages, but green ash, sycamore, pecan, persimmon, waterlocust, American elm, baldcypress, red maple, sugarberry, box-elder, and in some areas, silver maple are invaders preceding the next successional stage.

  4. Counseling Blacks (United States)

    Vontress, Clemmont E.


    Blacks have developed unique environmental perceptions, values, and attitudes, making it difficult for counselors to establish and maintain positive rapport. This article examines attitudinal ingredients posited by Carl Rogers for relevance to this problem, and suggests in-service training to help counselors and other professionals relate…

  5. Black Psyllium (United States)

    ... by mouth for up to 6 weeks reduces blood sugar in people with type 2 diabetes. Cancer. Diarrhea. Irritable bowel syndrome (IBS). Other conditions. ... with the dose. Diabetes: Black psyllium can lower blood sugar levels ... with type 2 diabetes by slowing down absorption of carbohydrates. Monitor blood ...

  6. Black hole astrophysics

    International Nuclear Information System (INIS)

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


    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.)

  7. Quantum black holes

    CERN Document Server

    Calmet, Xavier; Winstanley, Elizabeth


    Written by foremost experts, this short book gives a clear description of the physics of quantum black holes. The reader will learn about quantum black holes in four and higher dimensions, primordial black holes, the production of black holes in high energy particle collisions, Hawking radiation, black holes in models of low scale quantum gravity and quantum gravitational aspects of black holes.

  8. Bridging the Gap

    DEFF Research Database (Denmark)

    Kramer Overgaard, Majken; Broeng, Jes; Jensen, Monika Luniewska

    Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures.......Bridging the Gap (BtG) is a 2-year project funded by The Danish Industry Foundation. The goal of Bridging the Gap has been to create a new innovation model which will increase the rate at which Danish universities can spinout new technology ventures....

  9. Home media and children's achievement and behavior. (United States)

    Hofferth, Sandra L


    This study provides a national picture of the time American 6- to 12-year-olds spent playing video games, using the computer, and watching TV at home in 1997 and 2003, and the association of early use with their achievement and behavior as adolescents. Girls benefited from computer use more than boys, and Black children benefited more than White children. Greater computer use in middle childhood was associated with increased achievement for White and Black girls, and for Black but not White boys. Increased video game play was associated with an improved ability to solve applied problems for Black girls but lower verbal achievement for all girls. For boys, increased video game play was linked to increased aggressive behavior problems. © 2010 The Author. Child Development © 2010 Society for Research in Child Development, Inc.

  10. The Rural Dropout Problem: An Invisible Achievement Gap (United States)

    Johnson, Jerry; Strange, Marty; Madden, Karen


    This report reviews high school dropout rates and related factors in rural high schools throughout 15 Southern and Southwestern states. These schools are in districts that are among the 800 rural districts with the highest student poverty rate nationally. Seventy-seven percent of the "Rural 800" districts and 87 percent of the students in them are…

  11. Bridging the gender gap seven principles for achieving gender balance

    CERN Document Server

    Roseberry, Lynn


    Despite decades of efforts to promote gender equality, most leadership positions in business, politics, education, and even NGOs are occupied by men, and most people still work in occupations dominated by one sex. This book argues that gender imbalances in leadership and occupations are not simply a moral issue or an economic issue, but a governance issue. Gender imbalances persist in large part because the very people with the authority and influence to do something about them know very little about gender and how it works in their organizations and in society at large. Gender imbalanced governance is an expression of entrenched ideas about masculinity and femininity that lead to poor decision making. Improving the quality of governance requires action to counteract the main justifications for the status quo. Based on interviews and conversations with leaders and managers in Europe and the United States, the book presents seven of the most common explanations for persistent gender imbalances and shows how th...

  12. Acknowledging the gap between aspiration and achievement in ...

    African Journals Online (AJOL)

    ences in the field and in various policy arenas on the island and abroad. They were based on the following series of obser- vations recognised through academic publications. Firstly, forest - dependent people in Madagascar have often seen their de facto resource and land access rights threatened when conservation ...

  13. Magnetic fields around black holes (United States)

    Garofalo, David A. G.

    Newtonian results are excellent approximations for slowly spinning black holes. We proceed to address the issue of the spin dependence of the Blandford & Znajek power. The result we choose to highlight is our finding that given the validity of our assumption for the dynamical behavior of the so-called plunge region in black hole accretors, rotating black holes produce maximum Poynting flux via the Blandford & Znajek process for a black hole spin parameter of about a [approximate] 0.8. This is contrary to the conventional claim that the maximum electromagnetic flux is achieved for highest black hole spin.

  14. Bridging a Cultural Gap (United States)

    Leviatan, Talma


    There has been a broad wave of change in tertiary calculus courses in the past decade. However, the much-needed change in tertiary pre-calculus programmes--aimed at bridging the gap between high-school mathematics and tertiary mathematics--is happening at a far slower pace. Following a discussion on the nature of the gap and the objectives of a…

  15. The Hawking evaporation process of rapidly-rotating black holes: an almost continuous cascade of gravitons

    International Nuclear Information System (INIS)

    Hod, Shahar


    It is shown that rapidly-rotating Kerr black holes are characterized by the dimensionless ratio τ gap /τ emission = O(1), where τ gap is the average time gap between the emissions of successive Hawking quanta and τ emission is the characteristic timescale required for an individual Hawking quantum to be emitted from the black hole. This relation implies that the Hawking cascade from rapidly-rotating black holes has an almost continuous character. Our results correct some inaccurate claims that recently appeared in the literature regarding the nature of the Hawking black-hole evaporation process. (orig.)

  16. Gender Differences in Mathematics Achievement: An Exploratory ...

    African Journals Online (AJOL)

    The study examined whether there was a significant gender gap in mathematics achievement, and the nature of the gender gap. It also investigated factors associated with the differential performance of girls and boys in the mathematics class. The site for this study was a rural primary school in KwaZulu-Natal. Quantitative ...

  17. A Black Perspective on "The Case against College." (United States)

    Tribble, Israel, Jr.


    Concerned about Blacks and other minority groups, the author counters arguments such as the "Bird hypothesis" that college may not be worth costs and results to the individual and society. Examines Black higher education enrollment trends. Advocates higher education for Blacks to promote leadership, upward mobility, and achievement. (CSS)

  18. Culturally Responsive Social Skills Instruction for Adolescent Black Males (United States)

    Robinson-Ervin, Porsha; Cartledge, Gwendolyn; Keyes, Starr


    The cultural disconnect between black males and the school environment has been correlated with poor academic achievement and high discipline rates for Black males. Instructional strategies that draw upon the learner?s cultural background hold promise as one means for intervention. This paper addresses the social skills needs of black adolescent…

  19. Yes, Black Males Are Different, but Different Is Not Deficient (United States)

    Emdin, Christopher


    To address the chief issues surrounding low achievement of black males in schools one must acknowledge the inability of education systems to accept that there are ways of looking at the world, communication modes, and approaches to teaching that are unique to black males. The author developed five tools for teaching black males: Cogenerative…

  20. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan


    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has......International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  1. Achieving Standardization

    DEFF Research Database (Denmark)

    Henningsson, Stefan


    competitive, national customs and regional economic organizations are seeking to establish a standardized solution for digital reporting of customs data. However, standardization has proven hard to achieve in the socio-technical e-Customs solution. In this chapter, the authors identify and describe what has......International e-Customs is going through a standardization process. Driven by the need to increase control in the trade process to address security challenges stemming from threats of terrorists, diseases, and counterfeit products, and to lower the administrative burdens on traders to stay...... to be harmonized in order for a global company to perceive e-Customs as standardized. In doing so, they contribute an explanation of the challenges associated with using a standardization mechanism for harmonizing socio-technical information systems....

  2. From the Halls of Hough and Halstead: A Comparison of Black Students on Predominantly White and Predominantly Black Campuses. (United States)

    Hemmons, Willa Mae


    Compared attitudes and perspectives of Black college students attending a predominatly White college with those of students attending a predominantly Black college. Found that both groups expected to achieve higher economic and occupational status, though the White college was not seen as responding adequately to the needs of Black students. (GC)

  3. Black holes

    International Nuclear Information System (INIS)

    Carter, B.


    In years 1920 as a result of quantum mechanics principles governing the structure of ordinary matter, a sudden importance for a problem raised a long time ago by Laplace: what happens when a massive body becomes so dense that even light cannot escape from its gravitational field. It is difficult to conceive how could be avoided in the actual universe the accumulation of important masses of cold matter having been submitted to gravitational breaking down followed by the formation of what is called to day a black hole [fr

  4. Wide-Gap Chalcopyrites

    CERN Document Server

    Siebentritt, Susanne


    Chalcopyrites, in particular those with a wide band gap, are fascinating materials in terms of their technological potential in the next generation of thin-film solar cells and in terms of their basic material properties. They exhibit uniquely low defect formation energies, leading to unusual doping and phase behavior and to extremely benign grain boundaries. This book collects articles on a number of those basic material properties of wide-gap chalcopyrites, comparing them to their low-gap cousins. They explore the doping of the materials, the electronic structure and the transport through interfaces and grain boundaries, the formation of the electric field in a solar cell, the mechanisms and suppression of recombination, the role of inhomogeneities, and the technological role of wide-gap chalcopyrites.

  5. Single particle studies of black liquor gasification under pressurized conditions

    Energy Technology Data Exchange (ETDEWEB)

    Whitty, K.; Backman, R.; Hupa, M.; Backman, P.; Ek, P.; Hulden, S.T.; Kullberg, M.; Sorvari, V.


    The purpose of this project is to provide experimental data relevant to pressurized black liquor gasification concepts. Specifically, the following two goals will be achieved: Data on swelling, char yields and component release during pressurized pyrolysis of small samples of black liquor will be obtained. The reactivity and physical behavior of single black liquor droplets during simultaneous pyrolysis and gasification will be investigated. The structure and composition of black liquor char during formation and conversion will be studied. (orig.)

  6. Making Blackness, Making Policy


    Geller, Peter


    Too often the acknowledgment that race is a social construction ignores exactly how this construction occurs. By illuminating the way in which the category of blackness and black individuals are made, we can better see how race matters in America. Antidiscrimination policy, social science research, and the state's support of its citizens can all be improved by an accurate and concrete definition of blackness. Making Blackness, Making Policy argues that blackness and black people are literally...

  7. Ethnicity and Gender Gaps in Early Childhood (United States)

    Hansen, Kirstine; Jones, Elizabeth M.


    Gender differences in academic performance and achievement have been of policy concern for decades--both interest in lower performance by girls in the areas of mathematics and science and, more recently, in boys' underperformance in most other academic areas. Much previous research has focused on gender gaps, while overlooking other factors that…

  8. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Black holes; numerical relativity; nonlinear sigma. Abstract. Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. ... Theoretical and Computational Studies Group, Southampton College, Long Island University, Southampton, NY 11968, USA ...

  9. Gap length distributions by PEPR

    International Nuclear Information System (INIS)

    Warszawer, T.N.


    Conditions guaranteeing exponential gap length distributions are formulated and discussed. Exponential gap length distributions of bubble chamber tracks first obtained on a CRT device are presented. Distributions of resulting average gap lengths and their velocity dependence are discussed. (orig.)

  10. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili


    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  11. Complete surface plasmon-polariton band gap and gap-governed waveguiding, bending and splitting (United States)

    Wu, Fengqin; Han, Dezhuan; Hu, Xinhua; Liu, Xiaohan; Zi, Jian


    We show theoretically that a complete band gap for surface plasmon-polaritons (SPPs) can exist in a flat metal surface coated with a two-dimensional periodic array of dielectric cylinders. Based on the SPP band gap, gap-governed SPP waveguides, bends and splitters at telecom wavelengths can be achieved by introducing line defects. Numerical simulations show that the proposed SPP waveguides have a very low loss, while SPP bends and splitters can bend and split guided SPPs efficiently. The proposed SPP waveguides, bends and splitters could thus be exploited to construct compact integrated optical circuits in the emerging field of plasmonics.

  12. Scalar-Tensor Black Holes Embedded in an Expanding Universe (United States)

    Tretyakova, Daria; Latosh, Boris


    In this review we focus our attention on scalar-tensor gravity models and their empirical verification in terms of black hole and wormhole physics. We focus on a black hole, embedded in an expanding universe, describing both cosmological and astrophysical scales. We show that in scalar-tensor gravity it is quite common that the local geometry is isolated from the cosmological expansion, so that it does not backreact on the black hole metric. We try to extract common features of scalar-tensor black holes in an expanding universe and point out the gaps that must be filled.

  13. Gap Filling of Daily Sea Levels by Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Lyubka Pashova


    Full Text Available In the recent years, intelligent methods as artificial neural networks are successfully applied for data analysis from different fields of the geosciences. One of the encountered practical problems is the availability of gaps in the time series that prevent their comprehensive usage for the scientific and practical purposes. The article briefly describes two types of the artificial neural network (ANN architectures - Feed-Forward Backpropagation (FFBP and recurrent Echo state network (ESN. In some cases, the ANN can be used as an alternative on the traditional methods, to fill in missing values in the time series. We have been conducted several experiments to fill the missing values of daily sea levels spanning a 5-years period using both ANN architectures. A multiple linear regression for the same purpose has been also applied. The sea level data are derived from the records of the tide gauge Burgas, which is located on the western Black Sea coast. The achieved results have shown that the performance of ANN models is better than that of the classical one and they are very promising for the real-time interpolation of missing data in the time series.

  14. Semantic Gaps Are Dangerous

    DEFF Research Database (Denmark)

    Ejstrup, Michael; le Fevre Jakobsen, Bjarne

    Semantic gaps are dangerous Language adapts to the environment where it serves as a tool to communication. Language is a social agreement, and we all have to stick to both grammaticalized and non-grammaticalized rules in order to pass information about the world around us. As such language develops...... unpolite language and tend to create dangerous relations where specialy language creates problems and trouble that could be avoided if we had better language tools at hand. But we have not these tools of communication, and we are in a situation today where media and specially digital and social media......, supported by new possibilities of migration, create dangerous situations. How can we avoid these accidental gaps in language and specially the gaps in semantic and metaphoric tools. Do we have to keep silent and stop discusing certain isues, or do we have other ways to get acces to sufficient language tools...

  15. Where are the Gaps? (United States)

    Stoneham, Marshall

    Reading a Handbook like this gives a vivid picture of the enormous vigour and power of materials modelling. One is tempted to believe that we can answer all the questions materials technology might pose. Even if that were partly true, we should be identifying just what we do not know how to do. Some gaps will be depend on new hardware and software, especially when modelling quantum systems. Some gaps will be recognised only after some social or technological change has brought them into focus. Among the developments likely to stimulate innovation could be novel nanoelectronics, or the fields where physics meets biology. Still further gaps exist because we have been slaves to fashion, and have been drawn away from unpopular (roughly translating as "too difficult") fields; examples might include excited state spectroscopy, or electrical breakdown.

  16. Various response of Pinus tabulaeformis Carr. regeneration in artifical gaps. (United States)

    Wang, Zhibin; Zhao, Kuangji; Yang, Haijiao; Ma, Lvyi; Jia, Zhongkui


    Understanding the influence of gaps in promoting canopy recruitment will help to maintain structural stability and achieve continuous forest cover. We established three control plots and experimental plots with three replications each (gap sizes L-I, L-II, L-III, and L-IV) in a Chinese pine (Pinus tabulaeformis Carr.) plantation to test the short-term effects of gap size on the age distribution, density and growth, and annual height and ground diameter growth for regeneration established before (REBG) and after (REAG) gap creation. Age distribution exhibited an approximately normal distribution, with the numbers of REBG and REAG decreasing and increasing, respectively, as the age increased. Although there was no difference in density among gap size classes, regeneration growth positively responded to gap size, with maximum values observed in class L-III. Annual average height growth after (AAH-A) gap creation was significantly greater than that before (AAH-B) gap creation for REBG among gap sizes, suggesting that gaps promote the rapid growth of regeneration. However, the responses of height and ground diameter growth in REBG to gap size were not immediate and exhibited a response delay of 2-4 years. Similarly, for the height and ground diameter growth of REAG, significant differences were first observed within years 2-4 after germination in the same growing season for all gap size classes.

  17. The longevity gender gap

    DEFF Research Database (Denmark)

    Aviv, Abraham; Shay, Jerry; Christensen, Kaare


    In this Perspective, we focus on the greater longevity of women as compared with men. We propose that, like aging itself, the longevity gender gap is exceedingly complex and argue that it may arise from sex-related hormonal differences and from somatic cell selection that favors cells more...... resistant to the ravages of time. We discuss the interplay of these factors with telomere biology and oxidative stress and suggest that an explanation for the longevity gender gap may arise from a better understanding of the differences in telomere dynamics between men and women....

  18. Bridge the Gap

    DEFF Research Database (Denmark)

    Marselis, Randi


    This article focuses on photo projects organised for teenage refugees by the Society for Humanistic Photography (Berlin, Germany). These projects, named Bridge the Gap I (2015), and Bridge the Gap II (2016), were carried out in Berlin and brought together teenagers with refugee and German-majorit...... was produced – and sometimes not produced - within the projects. The importance of memory work in the context of refugee resettlement is often overlooked, but is particularly relevant when cultural encounters are organised in museums and exhibition galleries....

  19. Missing the gap

    DEFF Research Database (Denmark)

    Tanggaard, Lene; Glaveanu, Vlad Petre

    by the premise that difference and gaps are places where creative learning is intensified (Glaveanu & Gillespie, 2015). The public discourse around education is often concerned with minding or avoiding the gap by making education more relevant for or similar to the labour market, but what if facilitating...... creative learning at the borders need not minimize differences, but handle and learn from them? If not, schools and educational institutions risk becoming bad copies of the labour marked instead of enabling students to enter the market with something new, something radically dissimilar from what...

  20. Psychological Adjustment and Academic Achievement among Adolescents (United States)

    Mahmood, Khalid; Iqbal, Muhammad Maqsood


    This study was studied that emotional and behavioural problems of young students who are directly related to their academic achievement and thus play a vital role in the development of young learners carrier. This study helped to fill a gap by conducting an exploration of psychological adjustment and academic achievement among adolescents. It also…

  1. Numerical simulation of supersonic gap flow.

    Directory of Open Access Journals (Sweden)

    Xu Jing

    Full Text Available Various gaps in the surface of the supersonic aircraft have a significant effect on airflows. In order to predict the effects of attack angle, Mach number and width-to-depth ratio of gap on the local aerodynamic heating environment of supersonic flow, two-dimensional compressible Navier-Stokes equations are solved by the finite volume method, where convective flux of space term adopts the Roe format, and discretization of time term is achieved by 5-step Runge-Kutta algorithm. The numerical results reveal that the heat flux ratio is U-shaped distribution on the gap wall and maximum at the windward corner of the gap. The heat flux ratio decreases as the gap depth and Mach number increase, however, it increases as the attack angle increases. In addition, it is important to find that chamfer in the windward corner can effectively reduce gap effect coefficient. The study will be helpful for the design of the thermal protection system in reentry vehicles.

  2. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

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


    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...... 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...... 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....

  3. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

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


    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...

  4. Black holes. Chapter 6

    International Nuclear Information System (INIS)

    Penrose, R.


    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. Black Eye: First Aid (United States)

    First aid Black eye Black eye: First aid By Mayo Clinic Staff A black eye is caused by bleeding under the skin around the eye. Most injuries that cause a ... 13, 2018 Original article: . Mayo ...

  6. A Palm Size Micron-gap ThermoPhoto Voltaic (MTPV) Energy Converter

    National Research Council Canada - National Science Library

    DiMatteo, Robert


    The goal of this project was to demonstrate that enhanced photovoltaic cell output can be achieved as a function of the physical gap between emitter and receiver in a Micron-gap ThermoPhotoVoltaic (MTPV) system...

  7. Searching for High-energy, Horizon-scale Emissions from Galactic Black Hole Transients during Quiescence

    Energy Technology Data Exchange (ETDEWEB)

    Lin, L. C.-C.; Pu, Hung-Yi; Hirotani, Kouichi; Matsushita, Satoki; Inoue, Makoto [Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 10617, Taiwan (China); Kong, Albert K. H; Chang, Hsiang-Kuang [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Tam, Pak-Hin T., E-mail:, E-mail:, E-mail: [School of Physics and Astronomy, Sun Yat-Sen University, Zhuhai 519082 (China)


    We search for the gamma-ray counterparts of stellar-mass black holes using the long-term Fermi archive to investigate the electrostatic acceleration of electrons and positrons in the vicinity of the event horizon. We achieve this by applying the pulsar outer-gap model to their magnetospheres. When a black hole transient (BHT) is in a low-hard or quiescent state, the radiatively inefficient accretion flow cannot emit enough MeV photons that are required to sustain the force-free magnetosphere in the polar funnel via two-photon collisions. In this charge-starved gap region, an electric field arises along the magnetic field lines to accelerate electrons and positrons into ultra-relativistic energies. These relativistic leptons emit copious Gamma-rays via the curvature and inverse-Compton (IC) processes. It is found that these gamma-ray emissions exhibit a flaring activity when the plasma accretion rate typically stays between 0.01% and 0.005% of the Eddington value for rapidly rotating, stellar-mass black holes. By analyzing the detection limit determined from archival Fermi /Large Area Telescope data, we find that the 7-year averaged duty cycle of such flaring activities should be less than 5% and 10% for XTE J1118+480 and 1A 0620-00, respectively, and that the detection limit is comparable to the theoretical prediction for V404 Cyg. It is predicted that the gap emission can be discriminated from the jet emission if we investigate the high-energy spectral behavior or observe nearby BHTs during deep quiescence simultaneously in infrared wavelength and very-high energies.

  8. Two-dimensional microwave band-gap structures of different ...

    Indian Academy of Sciences (India)

    Abstract. We report the use of low dielectric constant materials to form two- dimensional microwave band-gap structures for achieving high gap-to-midgap ratio. The variable parameters chosen are the lattice spacing and the geometric structure. The se- lected geometries are square and triangular and the materials chosen ...

  9. Modelling and design of complete photonic band gaps in two ...

    Indian Academy of Sciences (India)

    Photonic crystal; complete photonic band gap; plane-wave expansion method. PACS Nos 71.20; 42.70.Q. 1. Introduction. Photonic band gap structures/photonic crystals, especially two-dimensional (2D) photonic crystals, which are dielectric structures periodic on length scale, have recently achieved much attention, as they ...

  10. Search for black holes

    International Nuclear Information System (INIS)

    Cherepashchuk, Anatolii M


    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)

  11. Estimating Gender Wage Gaps (United States)

    McDonald, Judith A.; Thornton, Robert J.


    Course research projects that use easy-to-access real-world data and that generate findings with which undergraduate students can readily identify are hard to find. The authors describe a project that requires students to estimate the current female-male earnings gap for new college graduates. The project also enables students to see to what…

  12. 'Mind the Gap!'

    DEFF Research Database (Denmark)

    Persson, Karl Gunnar

    This paper challenges the widely held view that sharply falling real transport costs closed the transatlantic gap in grain prices in the second half of the 19th century. Several new results emerge from an analysis of a new data set of weekly wheat prices and freight costs from New York to UK mark...

  13. Why "Gender" Disappeared from the Gender Gap: (Re-)Introducing Gender Identity Theory to Educational Gender Gap Research (United States)

    Vantieghem, Wendelien; Vermeersch, Hans; Van Houtte, Mieke


    Educational gender gap research tries to explain the differential achievement of boys and girls at secondary school, which manifests in many western countries. Several explanatory frameworks are used for this purpose, such as masculinities theory. In this review article, the history of educational gender gap research in Anglo-Saxon literature and…

  14. After-school enrichment and the activity theory: How can a management service organization assist schools with reducing the achievement gap among minority and non-minority students in science, technology, engineering, and mathematics (STEM) during the after-school hours? (United States)

    Flowers, Reagan D.

    The primary purpose of this study was to investigate how a management service organization can assist schools with reducing the achievement gap between minority and non-minority students in science, technology, engineering, and mathematics (STEM) during the after-school hours. Developing a strategic plan through creating a program that provides support services for the implementation of hands-on activities in STEM for children during the after-school hours was central to this purpose. This Project Demonstrating Excellence (PDE), a social action project, also presents historical and current after-school program developments in the nation. The study is quantitative and qualitative in nature. Surveys were utilized to quantitatively capture the opinions of participants in the social action project on three specific education related issues: (1) disparity in academic motivation of students to participate in after-school STEM enrichment programs; (2) whether teachers and school administrators saw a need for STEM after-school enrichment; and (3) developing STEM after-school programs that were centered on problem-solving and higher-order thinking skills to develop students' interest in STEM careers. The sample consisted of 50 participants comprised of students, teachers, and administrators. The focus groups and interviews provided the qualitative data for the study. The qualitative sample consisted of 14 participants comprised of students, parents and teachers, administrators, an education consultant, and a corporate sponsor. The empirical data obtained from the study survey, focus groups, and interviews provided a comprehensive profile on the current views and future expectations of STEM after-school enrichment, student and school needs, and community partnerships with STEM companies. Results of the study and review of the implementation of the social action project, C-STEM (communication, science, technology, engineering, and mathematics) Teacher and Student Support

  15. Black holes and holography

    International Nuclear Information System (INIS)

    Mathur, Samir D


    The idea of holography in gravity arose from the fact that the entropy of black holes is given by their surface area. The holography encountered in gauge/gravity duality has no such relation however; the boundary surface can be placed at an arbitrary location in AdS space and its area does not give the entropy of the bulk. The essential issues are also different between the two cases: in black holes we get Hawking radiation from the 'holographic surface' which leads to the information issue, while in gauge/gravity duality there is no such radiation. To resolve the information paradox we need to show that there are real degrees of freedom at the horizon of the hole; this is achieved by the fuzzball construction. In gauge/gravity duality we have instead a field theory defined on an abstract dual space; there are no gravitational degrees of freedom at the holographic boundary. It is important to understand the relations and differences between these two notions of holography to get a full understanding of the lessons from the information paradox.

  16. The Effect of School Quality on Black-White Health Differences: Evidence From Segregated Southern Schools (United States)

    Frisvold, David; Golberstein, Ezra


    This study assesses the effect of black-white differences in school quality on black-white differences in health in later life resulting from the racial convergence in school quality for cohorts born between 1910 and 1950 in southern states with segregated schools. Using data from the 1984 through 2007 National Health Interview Surveys linked to race-specific data on school quality, we find that reductions in the black-white gap in school quality led to modest reductions in the black-white gap in disability. PMID:23839102

  17. The effect of school quality on black-white health differences: evidence from segregated southern schools. (United States)

    Frisvold, David; Golberstein, Ezra


    This study assesses the effect of black-white differences in school quality on black-white differences in health in later life resulting from the racial convergence in school quality for cohorts born between 1910 and 1950 in southern states with segregated schools. Using data from the 1984-2007 National Health Interview Surveys linked to race-specific data on school quality, we find that reductions in the black-white gap in school quality led to modest reductions in the black-white gap in disability.

  18. Gendered Justice Gaps in Bosnia-Herzegovina

    DEFF Research Database (Denmark)

    Björkdahl, Annika; Mannergren Selimovic, Johanna


    A gendered reading of the liberal peacebuilding and transitional justice project in Bosnia-Herzegovina raises critical questions concerning the quality of the peace one hopes to achieve in transitional societies. By focusing on three-gendered justice gaps-the accountability, acknowledgement......, and reparations gaps-this article examines structural constraints for women to engage in shaping and implementing transitional justice, and unmasks transitional justice as a site for the long-term construction of the gendered post-conflict order. Thus, the gendered dynamics of peacebuilding and transitional...... justice have produced a post-conflict order characterized by gendered peace and justice gaps. Yet, we conclude that women are doing justice within the Bosnian-Herzegovina transitional justice project, and that their presence and participation is complex, multilayered, and constrained yet critical....

  19. Sustainability Tools Inventory - Initial Gaps Analysis | Science ... (United States)

    This report identifies a suite of tools that address a comprehensive set of community sustainability concerns. The objective is to discover whether "gaps" exist in the tool suite’s analytic capabilities. These tools address activities that significantly influence resource consumption, waste generation, and hazard generation including air pollution and greenhouse gases. In addition, the tools have been evaluated using four screening criteria: relevance to community decision making, tools in an appropriate developmental stage, tools that may be transferrable to situations useful for communities, and tools with requiring skill levels appropriate to communities. This document provides an initial gap analysis in the area of community sustainability decision support tools. It provides a reference to communities for existing decision support tools, and a set of gaps for those wishing to develop additional needed tools to help communities to achieve sustainability. It contributes to SHC 1.61.4

  20. Brane world black rings

    International Nuclear Information System (INIS)

    Sahay, Anurag; Sengupta, Gautam


    Five dimensional neutral rotating black rings are described from a Randall-Sundrum brane world perspective in the bulk black string framework. To this end we consider a rotating black string extension of a five dimensional black ring into the bulk of a six dimensional Randall-Sundrum brane world with a single four brane. The bulk solution intercepts the four brane in a five dimensional black ring with the usual curvature singularity on the brane. The bulk geodesics restricted to the plane of rotation of the black ring are constructed and their projections on the four brane match with the usual black ring geodesics restricted to the same plane. The asymptotic nature of the bulk geodesics are elucidated with reference to a bulk singularity at the AdS horizon. We further discuss the description of a brane world black ring as a limit of a boosted bulk black 2 brane with periodic identification

  1. Large gaps between primes


    Maynard, James


    We show that there exists pairs of consecutive primes less than $x$ whose difference is larger than $t(1+o(1))(\\log{x})(\\log\\log{x})(\\log\\log\\log\\log{x})(\\log\\log\\log{x})^{-2}$ for any fixed $t$. Our proof works by incorporating recent progress in sieve methods related to small gaps between primes into the Erdos-Rankin construction. This answers a well-known question of Erdos.

  2. Minding the Gap

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, Millicent Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Neutron & X-ray scattering provides nano- to meso-scale details of complex fluid structure; 1D electronic density maps dervied from SAXS yield molecular level insights; Neutron reflectivity provides substructure details of substrate supported complex fluids; Complex fluids composition can be optimized to support a wide variety of both soluble and membrane proteins; The water gap dimensions can be finely tuned through polymer component.

  3. Mind the Gap (United States)

    Fairbanks, Terry; Savage, Erica; Adams, Katie; Wittie, Michael; Boone, Edna; Hayden, Andrew; Barnes, Janey; Hettinger, Zach; Gettinger, Andrew


    Summary Objective Decisions made during electronic health record (EHR) implementations profoundly affect usability and safety. This study aims to identify gaps between the current literature and key stakeholders’ perceptions of usability and safety practices and the challenges encountered during the implementation of EHRs. Materials and Methods Two approaches were used: a literature review and interviews with key stakeholders. We performed a systematic review of the literature to identify usability and safety challenges and best practices during implementation. A total of 55 articles were reviewed through searches of PubMed, Web of Science and Scopus. We used a qualitative approach to identify key stakeholders’ perceptions; semi-structured interviews were conducted with a diverse set of health IT stakeholders to understand their current practices and challenges related to usability during implementation. We used a grounded theory approach: data were coded, sorted, and emerging themes were identified. Conclusions from both sources of data were compared to identify areas of misalignment. Results We identified six emerging themes from the literature and stakeholder interviews: cost and resources, risk assessment, governance and consensus building, customization, clinical work-flow and usability testing, and training. Across these themes, there were misalignments between the literature and stakeholder perspectives, indicating major gaps. Discussion Major gaps identified from each of six emerging themes are discussed as critical areas for future research, opportunities for new stakeholder initiatives, and opportunities to better disseminate resources to improve the implementation of EHRs. Conclusion Our analysis identified practices and challenges across six different emerging themes, illustrated important gaps, and results suggest critical areas for future research and dissemination to improve EHR implementation. PMID:27847961

  4. MV controlled spark gap

    International Nuclear Information System (INIS)

    Evdokimovich, V.M.; Evlampiev, S.B.; Korshunov, G.S.; Nikolaev, V.A.; Sviridov, Yu.F.; Khmyrov, V.V.


    A megavolt gas-filled trigatron gap with a sectional gas-discharge chamber having a more than three-fold range of operating voltages is described. The discharge chamber consists of ten sections, each 70 mm thick, made of organic glass. The sections are separated one from another by aluminium gradient rings to which ohmic voltage divider is connected. Insulational sections and gradient rings are braced between themselves by means of metal flanges through gaskets made of oil-resistant rubber with the help of fiberglass-laminate pins. The gap has two electrodes 110 mm in diameter. The trigatron ignition assembly uses a dielectric bushing projecting over the main electrode plane. Use has been made of a gas mixture containing 10% of SF 6 and 90% of air making possible to ensure stable gap operation without readjusting in the voltage range from 0.4 to 1.35 MV. The operation time lag in this range is equal to 10 μs at a spread of [ru

  5. Gender Gap or Program Gap? Students' Negotiations of Study Practice in a Course in Electromagnetism (United States)

    Andersson, Staffan; Johansson, Anders


    This study of achievement differences, as reflected by course grades, on a third-semester electromagnetism course at a Swedish research university was motivated by instructor concerns about gender inequalities. Quantitative analysis showed a gender gap in course grades between female and male students for the period of fall 2007 to spring 2013.…


    Directory of Open Access Journals (Sweden)

    Ting-Chi Wei


    Full Text Available The existence of subordinate gaps in Mandarin Chinese casts doubt on analyses built on canonical coordinate gapping. We observe that the minimality of contrastive focus and the type of subordinate clause determine the acceptability of a missing gap in subordinate structure. Along this vein, we propose that a semantic-based deletion account can be used to interpret gapping in Mandarin. Such account relies on two violable constraints, AvoidF and Focus condition on gapping (Schwarzchild 1999, Merchant 2001 to compute the acceptability of a gap.

  7. Home Media and Children's Achievement and Behavior (United States)

    Hofferth, Sandra L.


    This study provides a national picture of the time American 6- to 12-year-olds spent playing video games, using the computer, and watching TV at home in 1997 and 2003, and the association of early use with their achievement and behavior as adolescents. Girls benefited from computer use more than boys, and Black children benefited more than White…

  8. GapBlaster-A Graphical Gap Filler for Prokaryote Genomes. (United States)

    de Sá, Pablo H C G; Miranda, Fábio; Veras, Adonney; de Melo, Diego Magalhães; Soares, Siomar; Pinheiro, Kenny; Guimarães, Luis; Azevedo, Vasco; Silva, Artur; Ramos, Rommel T J


    The advent of NGS (Next Generation Sequencing) technologies has resulted in an exponential increase in the number of complete genomes available in biological databases. This advance has allowed the development of several computational tools enabling analyses of large amounts of data in each of the various steps, from processing and quality filtering to gap filling and manual curation. The tools developed for gap closure are very useful as they result in more complete genomes, which will influence downstream analyses of genomic plasticity and comparative genomics. However, the gap filling step remains a challenge for genome assembly, often requiring manual intervention. Here, we present GapBlaster, a graphical application to evaluate and close gaps. GapBlaster was developed via Java programming language. The software uses contigs obtained in the assembly of the genome to perform an alignment against a draft of the genome/scaffold, using BLAST or Mummer to close gaps. Then, all identified alignments of contigs that extend through the gaps in the draft sequence are presented to the user for further evaluation via the GapBlaster graphical interface. GapBlaster presents significant results compared to other similar software and has the advantage of offering a graphical interface for manual curation of the gaps. GapBlaster program, the user guide and the test datasets are freely available at It requires Sun JDK 8 and Blast or Mummer.

  9. GapBlaster-A Graphical Gap Filler for Prokaryote Genomes.

    Directory of Open Access Journals (Sweden)

    Pablo H C G de Sá

    Full Text Available The advent of NGS (Next Generation Sequencing technologies has resulted in an exponential increase in the number of complete genomes available in biological databases. This advance has allowed the development of several computational tools enabling analyses of large amounts of data in each of the various steps, from processing and quality filtering to gap filling and manual curation. The tools developed for gap closure are very useful as they result in more complete genomes, which will influence downstream analyses of genomic plasticity and comparative genomics. However, the gap filling step remains a challenge for genome assembly, often requiring manual intervention. Here, we present GapBlaster, a graphical application to evaluate and close gaps. GapBlaster was developed via Java programming language. The software uses contigs obtained in the assembly of the genome to perform an alignment against a draft of the genome/scaffold, using BLAST or Mummer to close gaps. Then, all identified alignments of contigs that extend through the gaps in the draft sequence are presented to the user for further evaluation via the GapBlaster graphical interface. GapBlaster presents significant results compared to other similar software and has the advantage of offering a graphical interface for manual curation of the gaps. GapBlaster program, the user guide and the test datasets are freely available at It requires Sun JDK 8 and Blast or Mummer.

  10. Black Holes in Supergravity: the non-BPS Branch

    CERN Document Server

    Gimon, Eric G; Simon, Joan; PH-TH


    We construct extremal, spherically symmetric black hole solutions to 4D supergravity with charge assignments that preclude BPS-saturation. In particular, we determine the ground state energy as a function of charges and moduli. We find that the mass of the non-BPS black hole remains that of a marginal bound state of four basic constituents throughout the entire moduli space and that there is always a non-zero gap above the BPS bound.

  11. Black holes in supergravity: the non-BPS branch

    Energy Technology Data Exchange (ETDEWEB)

    Gimon, Eric; Gimon, Eric G.; Larsen, Finn; Simon, Joan


    We construct extremal, spherically symmetric black hole solutions to 4D supergravity with charge assignments that preclude BPS-saturation. In particular, we determine the ground state energy as a function of charges and moduli. We find that the mass of the non-BPS black hole remains that of a marginal bound state of four basic constituents throughout the entire moduli space and that there is always a non-zero gap above the BPS bound.

  12. Full-waveform inversion: Filling the gaps

    KAUST Repository

    Beydoun, Wafik B.


    After receiving an outstanding response to its inaugural workshop in 2013, SEG once again achieved great success with its 2015 SEG Middle East Workshop, “Full-waveform inversion: Filling the gaps,” which took place 30 March–1 April 2015 in Abu Dhabi, UAE. The workshop was organized by SEG, and its partner sponsors were Saudi Aramco (gold sponsor), ExxonMobil, and CGG. Read More:

  13. The Gap and the origin of the fundamental forces (United States)

    Zichichi, Antonino


    The energy level where the best values of the three fundamental gauge couplings (α1,α2,α3) converge is at least two orders of magnitude below the Planck energy level. The existence of this Gap could imply that the gravitational force ‘comes into being’ before QED, QFD and QCD. The most interesting consequence of the Gap would then be the existence of matter whose charge is only the gravitational charge. If this is so, events should be detected where only gravitational waves are produced. Primordial black holes (PBHs) would be produced much more frequently than the standard black holes (SBHs) since SBHs would be ‘derivative’ effects produced later, after matter made with protons, electrons, neutrons, and stars can exist. Collisions between PBHs generating only gravitational waves should be more frequent than SBHs collisions.

  14. Black hole hair removal

    International Nuclear Information System (INIS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke


    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.

  15. The Black Studies Boondoggle (United States)

    Long, Richard A.


    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)

  16. Black-Body Radiation

    Indian Academy of Sciences (India)

    Keywords. Black-body radiation; thermal radiation; heat; electromagnetic radiation; Stefan's Law; Stefan–Boltzmann Law; Wien's Law; Rayleigh–Jeans Law; black-body spectrum; ultraviolet catastrophe; zero point energy; photon.

  17. Closing the stop gap

    International Nuclear Information System (INIS)

    Czakon, Michal; Mitov, Alexander; Papucci, Michele; California Univ., Berkeley, CA; Ruderman, Joshua T.; California Univ., Berkeley, CA; New York Univ., NY; Weiler, Andreas; CERN - European Organization for Nuclear Research, Geneva


    Light stops are a hallmark of the most natural realizations of weak-scale supersymmetry. While stops have been extensively searched for, there remain open gaps around and below the top mass, due to similarities of stop and top signals with current statistics. We propose a new fast-track avenue to improve light stop searches for R-parity conserving supersymmetry, by comparing top cross section measurements to the theoretical prediction. Stop masses below ∝180 GeV can now be ruled out for a light neutralino. The possibility of a stop signal contaminating the top mass measurement is also briefly addressed.

  18. Photonic band gap materials (United States)

    Cassagne, D.

    Photonic band gap materials Photonic band gap materials are periodic dielectric structures that control the propagation of electromagnetic waves. We describe the plane wave method, which allows to calculate the band structures of photonic crystals. By symmetry analysis and a perturbative approach, we predict the appearance of the low energy photonic band gaps of hexagonal structures. We propose new two-dimensional structures called graphite and boron nitride. Using a transfer matrix method, we calculate the transmission of the graphite structure and we show the crucial role of the coupling with external modes. We study the appearance of allowed modes in the photonic band gap by the introduction of localized defects in the periodicity. Finally, we discuss the properties of opals formed by self-organized silica microspheres, which are very promising for the fabrication of three-dimensional photonic crystals. Les matériaux à bandes interdites photoniques sont des structures diélectriques périodiques qui contrôlent la propagation des ondes électromagnétiques. Nous décrivons la méthode des ondes planes qui permet de calculer les structures de bandes des cristaux photoniques. Par une analyse de la symétrie et une approche perturbative, nous précisons les conditions d'existence des bandes interdites de basse énergie. Nous proposons de nouvelles structures bidimensionnelles appelées graphite et nitrure de bore. Grâce à une méthode de matrices de transfert, nous calculons la transmission de la structure graphite et nous mettons en évidence le rôle fondamental du couplage avec les modes extérieurs. Nous étudions l'apparition de modes permis dans la bande interdite grâce à l'introduction de défauts dans la périodicité. Enfin, nous discutons les propriétés des opales constituées de micro-billes de silice auto-organisées, qui sont très prometteuses pour la fabrication de cristaux photoniques tridimensionnels.

  19. gap: Genetic Analysis Package

    Directory of Open Access Journals (Sweden)

    Jing Hua Zhao


    Full Text Available A preliminary attempt at collecting tools and utilities for genetic data as an R package called gap is described. Genomewide association is then described as a specific example, linking the work of Risch and Merikangas (1996, Long and Langley (1997 for family-based and population-based studies, and the counterpart for case-cohort design established by Cai and Zeng (2004. Analysis of staged design as outlined by Skol et al. (2006 and associate methods are discussed. The package is flexible, customizable, and should prove useful to researchers especially in its application to genomewide association studies.

  20. Dynamics of black holes


    Hayward, Sean A.


    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  1. Black holes are hot

    International Nuclear Information System (INIS)

    Gibbons, G.


    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.)

  2. Gaps in nonsymmetric numerical semigroups

    International Nuclear Information System (INIS)

    Fel, Leonid G.; Aicardi, Francesca


    There exist two different types of gaps in the nonsymmetric numerical semigroups S(d 1 , . . . , d m ) finitely generated by a minimal set of positive integers {d 1 , . . . , d m }. We give the generating functions for the corresponding sets of gaps. Detailed description of both gap types is given for the 1st nontrivial case m = 3. (author)

  3. Monopole black hole skyrmions


    Moss, I.G.; Shiiki, N.; Winstanley, E.


    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.

  4. Alcoholism and Blacks. (United States)

    Mosley, Bertha; And Others


    Notes that in America, knowledge base concerning alcoholism is concentrated on drinking patterns of Whites, and that Black Americans often differ in their drinking behavior, resulting in a need to clarify issues regarding alcoholism and Blacks. Provides theoretical information useful in better discerning drinking behavior of Blacks. (Author/NB)

  5. 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 ...

  6. Genocide and Black Ecology (United States)

    Sinnette, Calvin H.


    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)

  7. Interior structure of rotating black holes. III. Charged black holes

    International Nuclear Information System (INIS)

    Hamilton, Andrew J. S.


    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.

  8. GAP-REACH (United States)

    Lewis-Fernández, Roberto; Raggio, Greer A.; Gorritz, Magdaliz; Duan, Naihua; Marcus, Sue; Cabassa, Leopoldo J.; Humensky, Jennifer; Becker, Anne E.; Alarcón, Renato D.; Oquendo, María A.; Hansen, Helena; Like, Robert C.; Weiss, Mitchell; Desai, Prakash N.; Jacobsen, Frederick M.; Foulks, Edward F.; Primm, Annelle; Lu, Francis; Kopelowicz, Alex; Hinton, Ladson; Hinton, Devon E.


    Growing awareness of health and health care disparities highlights the importance of including information about race, ethnicity, and culture (REC) in health research. Reporting of REC factors in research publications, however, is notoriously imprecise and unsystematic. This article describes the development of a checklist to assess the comprehensiveness and the applicability of REC factor reporting in psychiatric research publications. The 16-itemGAP-REACH© checklist was developed through a rigorous process of expert consensus, empirical content analysis in a sample of publications (N = 1205), and interrater reliability (IRR) assessment (N = 30). The items assess each section in the conventional structure of a health research article. Data from the assessment may be considered on an item-by-item basis or as a total score ranging from 0% to 100%. The final checklist has excellent IRR (κ = 0.91). The GAP-REACH may be used by multiple research stakeholders to assess the scope of REC reporting in a research article. PMID:24080673

  9. Gap Task Force

    CERN Multimedia

    Lissuaer, D

    One of the more congested areas in the ATLAS detector is the GAP region (the area between the Barrel Calorimeter and the End Cap calorimeter) where Inner Detector services, LAr Services and some Tile services all must co-habitat in a very limited area. It has been clear for some time that the space in the GAP region is not sufficient to accommodate all that is needed. In the last few month additional problems of routing all the services to Z=0 have been encountered due to the very limited space between the Tile Calorimeter and the first layer of Muon chambers. The Technical Management Board (TMB) and the Executive Board (EB) decided in the middle of March to establish a Task Force to look at this problem and come up with a solution within well-specified guidelines. The task force consisted of experts from the ID, Muon, Liquid Argon and Tile systems in addition to experts from the Technical Coordination team and the Physics coordinator. The task force held many meetings and in general there were some very l...

  10. Closing the value gap

    International Nuclear Information System (INIS)

    Snyder, A.V.


    It's a predicament. For the most part, investor-owned electric utilities trade at a deep discount to the actual (that is, replacement-cost) value to their assets. That's because most utilities fail to earn real returns large enough to justify raising and investing capital. The result is a value gap, where overall market value is significantly lower than the replacement costs of the assets. This gap is wider for utilities than for virtually any other industry in our economy. In addition to providing education and awareness, senior management must determine which businesses and activities create value and which diminish it. Then, management must allocate capital and human resources appropriately, holding down investments in value-diminishing areas until they can improve their profitability, and aggressively investing in value-enhancing businesses while preserving their profitability. But value management must not stop with resource-allocation decisions. To create a lasting transition to a value management philosophy, the utility's compensation system must also change: executives will have motivation to create value when compensation stems from this goal, not from such misleading accounting measures as earnings-per-share growth or ROE. That requires clear value-creation goals, and the organization must continuously evaluate top management's performance in light of the progress made toward those goals

  11. Black holes in binary stars

    NARCIS (Netherlands)

    Wijers, R.A.M.J.


    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

  12. Black hole levitron

    International Nuclear Information System (INIS)

    Arsiwalla, Xerxes D.; Verlinde, Erik P.


    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.

  13. Challenging the Black Church Narrative: Race, Class, and Homosexual Attitudes. (United States)

    Irizarry, Yasmiyn A; Perry, Ravi K


    In recent years, scholars have pointed to the Black church as the driving force behind Blacks' more conservative lesbian, gay, bisexual, and transgendered (LGBT) attitudes. Although evidence suggests a robust association between religiosity and LGBT attitudes, contemporary scholarship has not examined the role of class or the extent to which religiosity actually explains these trends. Using the 2004-2014 waves of the General Social Survey, we find that class moderates in the effect of race on negative LGBT attitudes, resulting in a noticeably larger gap between middle-class Blacks and Whites than in the top or the bottom of the class distribution. Although religiosity and moralization explain a portion of racial differences in homosexual attitudes across class groups, we find that neither fully accounts for the more conservative attitudes of the Black middle class. We conclude by discussing the shortcomings of these narratives for understanding Blacks' more conservative LGBT attitudes.

  14. The Adaptation Finance Gap Report

    DEFF Research Database (Denmark)

    UNEP’s Adaptation Gap Report series focuses on Finance, Technology and Knowledge gaps in climate change adaptation. It compliments the Emissions Gap Report series, and explores the implications of failing to close the emissions gap. The report builds on a 2014 assessment by the United Nations...... Environment Programme (UNEP), which laid out the concept of ‘adaptation gaps’ and outlined three such gaps: technology, finance and knowledge. The 2016 Adaptation Gap Report assesses the difference between the financial costs of adapting to climate change in developing countries and the amount of money...... and highlights challenges associated with measuring progress towards fulfilling the adaptation finance gap, while informing national and international efforts to advance adaptation. It analyses the ‘adaptation finance gap’ against the background of the provisions laid out in the Paris Agreement, and benefits...

  15. Gender gap or program gap? Students' negotiations of study practice in a course in electromagnetism (United States)

    Andersson, Staffan; Johansson, Anders


    [This paper is part of the Focused Collection on Gender in Physics.] This study of achievement differences, as reflected by course grades, on a third-semester electromagnetism course at a Swedish research university was motivated by instructor concerns about gender inequalities. Quantitative analysis showed a gender gap in course grades between female and male students for the period of fall 2007 to spring 2013. Dynamics behind this gap were explored through interpretative discourse analysis on interviews of 21 students who had recently passed the course. A recurring pattern was identified in the interviews. Students described studying electromagnetism as either studying to pass or studying to learn. Their choice of practice was influenced by the significance recognized in the course, which primarily was discussed in relation to program affiliation. Students stressed that perceived differences, in their study context, were larger between students affiliated with different programs than between male and female students on the same program. This was supported by quantitative analysis of course grades in relation to study programs, where the grade difference between female and male students on the same program in most cases were not statistically significant. The gender gap in grades for the whole course was related to different achievements on different programs. Programs further from the discipline of physics had lower mean grades and also enrolled a larger fraction of female students. Society-wide gender differences in interest and study choice are reflected in the grades on this single course. These results displace the achievement gap from the level of individuals to that of programs, and the gender gap from a difference in achievement to a difference in study choice. We discuss the implications of this shift of perspective in relation to gender differences for both research and teaching.

  16. Capturing American black ducks in tidal waters (United States)

    Harrison, M.K.; Haramis, G.M.; Jorde, Dennis G.; Stotts, D.B.


    We modified conventional, funnel-entrance dabbling duck bait traps to increase captures for banding of American Black Ducks (Anas rubripes) in tidal saltmarsh habitats of Smith Island, Maryland, one of the few remaining strongholds for breeding Black Ducks in the Chesapeake Bay. Traps and trapping techniques were adapted to tidal creeks and refined to improve capture rate, reduce mortality, and minimize interference by gulls. Best results were achieved by synchronizing trapping with predawn, low-tide foraging patterns of Black Ducks. Trap entrances were critical to retaining ducks, and use of loafing platforms reduced overall mortality to 3% of captures per year. We captured 3071 Black Ducks during the 14-year period, 1984-199

  17. Minding the gap

    Directory of Open Access Journals (Sweden)

    Mia Carlberg


    Full Text Available The plan for the Round table session was to focus on organizational and social/cultural differences between librarians and faculty with the aim to increase our awareness of the differences when we try to find ways to cooperate within the academy or school. This may help us to sort things out, experience acceptance and take adequate actions, saving energy and perhaps be less frustrated.  The questions that the workshop addressed were: What is in the gap between librarians and faculty when dealing with information literacy? How can we fill the gap? Participants discussed this in detail with the aim of together finding ways to understand it better and make it possible to find ways to fill this gap. By defining it and thereby making it easier to work out a strategy for future action to improve the teaching of information literacy, including listing possible, impossible or nearly impossible ways. The springboard to the discussion was extracted from some projects that the workshop leader has been engaged in since 2009. The first example is a research circle where Uppsala University Library used action research to observe and understand the process when we had the opportunity to implement information literacy classes with progression in an undergraduate program. What worked well? What did not? Why? This work was described together with other examples from Uppsala University to an international panel working with quality issues. What did they think of our work? May this change the ways we are working? How? Another example is an ongoing joint project where librarians and faculty members are trying to define ways to increase the cooperation between the library and faculty and make this cooperation sustainable. Recent experience from this was brought to the discussion.   There are an overwhelming number of papers written in this field. A few papers have inspired these ideas. One article in particular: Christiansen, L., Stombler, M. & Thaxton, L. (2004. A

  18. Topology, entropy, and Witten index of dilaton black holes

    International Nuclear Information System (INIS)

    Gibbons, G.W.; Kallosh, R.E.


    We have found that for extreme dilaton black holes an inner boundary must be introduced in addition to the outer boundary to give an integer value to the Euler number. The resulting manifolds have (if one identifies imaginary time) a topology S 1 xRxS 2 and Euler number χ=0 in contrast with the nonextreme case with χ=2. The entropy of extreme U(1) dilaton black holes is already known to be zero. We include a review of some recent ideas due to Hawking on the Reissner-Nordstroem case. By regarding all extreme black holes as having an inner boundary, we conclude that the entropy of all extreme black holes, including [U(1)] 2 black holes, vanishes. We discuss the relevance of this to the vanishing of quantum corrections and the idea that the functional integral for extreme holes gives a Witten index. We have studied also the topology of ''moduli space'' of multi-black-holes. The quantum mechanics on black hole moduli spaces is expected to be supersymmetric despite the fact that they are not hyper-Kaehler since the corresponding geometry has a torsion unlike the BPS monopole case. Finally, we describe the possibility of extreme black hole fission for states with an energy gap. The energy released, as a proportion of the initial rest mass, during the decay of an electromagnetic black hole is 300 times greater than that released by the fission of a 235 U nucleus

  19. Guiding contact by coupling the taus of gaps. (United States)

    Lee, D N; Georgopoulos, A P; Clark, M J; Craig, C M; Port, N L


    Animals control contact with surfaces when locomoting, catching prey, etc. This requires sensorily guiding the rate of closure of gaps between effectors such as the hands, feet or jaws and destinations such as a ball, the ground and a prey. Control is generally rapid, reliable and robust, even with small nervous systems: the sensorimotor processes are therefore probably rather simple. We tested a hypothesis, based on general tau theory, that closing two gaps simultaneously, as required in many actions, might be achieved simply by keeping the taus of the gaps coupled in constant ratio. tau of a changing gap is defined as the time-to-closure of the gap at the current closure-rate. General tau theory shows that tau of a gap could, in principle, be directly sensed without needing to sense either the gap size or its rate of closure. In our experiment, subjects moved an effector (computer cursor) to a destination zone indicated on the computer monitor, to stop in the zone just as a moving target cursor reached it. The results indicated the subjects achieved the task by keeping tau of the gap between effector and target coupled to tau of the gap between the effector and the destination zone. Evidence of tau-coupling has also been found, for example, in bats guiding landing using echolocation. Thus, it appears that a sensorimotor process used by different species for coordinating the closure of two or more gaps between effectors and destinations entails constantly sensing the taus of the gaps and moving so as to keep the taus coupled in constant ratio.

  20. Towards a pro-employment growth path | Black | New Agenda ...

    African Journals Online (AJOL)

    Black is a professor with the Policy Research in International Services and Manufacturing (PRISM) unit at the University of Cape Town's School of Economics, where Gerwel and Hasson are researchers. This paper draws on a full-length article by Black and Gerwel, “Shifting the growth path to achieve employment-intensive ...

  1. Bridging the Evaluation Gap

    Directory of Open Access Journals (Sweden)

    Paul Wouters


    Full Text Available Paul Wouters’ essay is concerned with bridging the gap between what we value in our academic work and how we are assessed in formal evaluation exercises. He reflects on the recent evaluation of his own center, and reminds us that it is productive to see evaluations not as the (obviously impossible attempt to produce a true representation of past work, but rather as the exploration and performance of “who one wants to be.” Reflecting on why STS should do more than just play along to survive in the indicator game, he suggests that our field should contribute to changing its very rules. In this endeavor, the attitude and sensibilities developed in our field may be more important than any specific theoretical concepts or methodologies.

  2. Finding the gaps (United States)

    Stoneham, A. M.

    Much of the pioneering work on radiation damage was based on very simple potentials. Potentials are now much more sophisticated and accurate. Self-consistent molecular dynamics is routine for adiabatic energy surfaces, at least for modest numbers of atoms and modest timescales. This means that non-equilibrium nuclear processes can be followed dynamically. It might also give the illusion that any damage process can be modelled with success. Sadly, this is not yet so. This paper discusses where the gaps lie, and specifically three groups of challenges. The first challenge concerns electronic excited states. The second challenge concerns timescales, from femtoseconds to tens of years. The third challenge concerns length scales, and the link between microscopic (atomistic) and mesoscopic (microstructural) scales. The context of these challenges is materials modification by excitation: the removal of material, the modification of bulk or surface material, the altering of rates of processes or changing of branching ratios, and damage, good or bad.

  3. Closing the health gap. (United States)

    Marmot, Michael


    One way of characterising the good society is one that has achieved a high degree of health equity. For a low-income country, one route to this achievement is to increase national income. But other features of society come to the fore, for low, middle and high-income societies alike. In England, my review of health inequalities highlighted: good early child development, education and life long learning, employment and working conditions, having enough income to lead a healthy life, healthy and sustainable places to live and work, taking a social determinants approach to prevention. Taking action on these requires commitment and cross-government action.

  4. Black Women's Faculty Voices in New Mexico: Invisible Assets Silent No More (United States)

    Woodley, Xeturah Monique


    There continues to exist a lack of Black women faculty at institutions of higher education (Moses, 1989; Collins, 1991; Gregory, 2001). Although we can see an increase in the number of research projects focused on Black women faculty there still remains a significant gap in the research (Glover, 2006; Foster-Williamson, 2002; Thomas &…

  5. Making up the Gap

    NARCIS (Netherlands)

    Lex Herweijer


    A growing number of young people in the Netherlands have a non-Western ethnic background. Education plays a key role in their integration into Dutch society. Promoting participation in education by these young non-Western migrants and boosting their educational achievement are accordingly

  6. Gaps and Contracts. (United States)

    Donovan, Marilee; And Others


    Describes a workshop strategy which provides a mechanism for implementing change and facilitates the administrative support necessary to improve nursing care in institutional settings. Participants learn to set realistic, high-priority goals; implement change theory; and use available resources to achieve a goal. (CT)

  7. The Black Sea one decade after the Bucharest Convention an overview of the international activities in the Black Sea region

    International Nuclear Information System (INIS)

    Goektepe, G.


    The catastrophic degradation of the Black Sea in a period of four decade has been the major concern of the Black Sea countries and international communities since Bucharest Convention signed in 1992. The Black Sea Region has became a challenging international arena for political scientific and socio-economic activities. Intensive international programmes and establishment of governmental and Non Governmental Organizational structures of the 1990s including Black Sea Economic Cooperation (BSEC), Black Sea Environmental Programme(BSEP), Environmental Programme for the Danube River Basin, Marine Environmental Assessment of the Black Sea Region Technical Cooperation Programme by the IAEA and establishment of the Black Sea Commission Permanent Secretariat are some of the major international efforts of the past decade that emphasizes the multi-nationality and large dimension of the Black Sea environmental management issues. The environmental degradation of the Black Sea is briefly reviewed based on the BSEP reports and data available for land based pollution sources. The environmental risk of marine vessel accidents are indicated and environmental safety concern is emphasized under the current conditions of intense energy transportation projects in the Black Sea and Caspian regions. The international policy actions, co-operation issues and scientific programmes of the past decade are overviewed with emphasis on the international achievements. Concluding remarks include the vital importance of continuation of the international commitments and sharing the political, scientific and socio-economic responsibility on the transboundary environmental pollution, rehabilitation and the safety issues of the Black Sea

  8. Current knowledge, gaps and challenges in the Southern European Seas (United States)

    Papathanassiou, Evangelos


    New knowledge advances our current understanding on the selection and application of the appropriate tools for assessing the state of the marine environment in the Southern European Seas (SES). Diminishing the lack of knowledge is a prerequisite for sound policy decisions. Although gaps and knowledge are fewer today, the health of marine and coastal ecosystems in the SES is under pressure and shows, in places, some signs of deterioration and declining quality. Overall, there is a lack of data accessibility and long time series in the SES, while in many cases poorly constrained processes cannot really support knowledge-based policy making (e.g. ecosystem functioning, climate change, fisheries management, etc.). New knowledge has to be produced and excellence must be promoted to support sustainable economic growth. At the same time, existing and new capacities have to be upgraded and increased in order to support sustainable convergence between SES countries. There are several gaps that have been identified and processes that have been poorly understood in the SES, mainly from research projects that have been working at basin level. The main research priorities that have been identified from the SeasERA Project for both, the Mediterranean and the Black Sea include: the climate change and its impacts, the hydrological cycle, the ventilation and the inter-basin coupling, the marine biodiversity and the provision of goods and services, the marine protected areas, the deep sea ecosystems, the biological invasions, the marine pollution and the ocean and human health, the renewable energy, the maritime transport, the fisheries and aquaculture activities and the biotechnology and the exploitation of marine resources for industrial application. More important, however, is the fact that the economic, the social and the scientific and the environmental challenges must be collectively tackled. They should have prioritisation and clear objectives as well as data sharing for

  9. Panopticonics: The Control and Surveillance of Black Female Athletes in a Collegiate Athletic Program. (United States)

    Foster, Kevin Michael


    Analyzes black female student athletes' participation in an elite collegiate athletic program by showing how the program maximizes black females' athletic and academic potential through surveillance, control, and discipline. The program instills in black female athletes a model of womanhood whereby they come to expect and achieve academic and…

  10. Young Black Males: Resilience and the Use of Capital to Transform School "Failure" (United States)

    Wright, Cecile; Maylor, Uvanney; Becker, Sophie


    This article addresses the idea of "failure" of young black males with respect to schooling. Perceptions of black masculinity are often linked to "underperformance" in the context of school academic achievement. This article addresses how young black men, by great personal effort, recover from school "failure". It…

  11. Exfoliated layers of black phosphorus as saturable absorber for ultrafast solid-state laser. (United States)

    Zhang, Baitao; Lou, Fei; Zhao, Ruwei; He, Jingliang; Li, Jing; Su, Xiancui; Ning, Jian; Yang, Kejian


    High-quality black phosphorus (BP) saturable absorber mirror (SAM) was successfully fabricated with few-layered BP (phosphorene). By employing the prepared phosphorene SAM, we have demonstrated ultrafast pulse generation from a BP mode-locked bulk laser for the first time to our best knowledge. Pulses as short as 6.1 ps with an average power of 460 mW were obtained at the central wavelength of 1064.1 nm. Considering the direct and flexible band gap for different layers of phosphorene, this work may provide a possible method for fabricating BP SAM to achieve ultrafast solid-state lasers in IR and mid-IR wavelength region.

  12. Measuring the Gap

    Directory of Open Access Journals (Sweden)

    Xinshu She MD, MPH


    Full Text Available China is a large country where rapid development is accompanied by growing inequalities. How economic inequalities translate to health inequalities is unknown. Baseline health assessment is lacking among rural Chinese children. We aimed at assessing baseline student health of rural Chinese children and comparing them with those of urban children of similar ages. A cross-sectional study was conducted using the 2003 Global School-Based Student Health Survey among 100 students Grade 4 to 6 from rural Guizhou, China. Results were summarized and compared with public data from urban Beijing using multivariate logistic regression models. Rural children are more likely to not wash their hands before a meal (odds ratio [OR] = 5.71, P .05. Rural parents are more likely to not know their children’s whereabouts (OR = 1.81, P < .05. Rural children are more than 4 times likely to have serious injuries (OR = 4.64, P < .01 and to be bullied (OR = 4.01, P < .01. In conclusion, school-age rural Chinese children exhibit more health risk behaviors and fewer protective factors at baseline compared to their urban counterparts. Any intervention aimed at improving child health should take this distributive gap into consideration.

  13. Radiating gap filler

    International Nuclear Information System (INIS)


    Full text: In May, corrosion on the outside wall of the over 50 year old Canadian Chalk River reactor vessel caused a heavy water leak and the reactor was shut down triggering worldwide a nuclear medicine shortage. The reactor is also a major supplier of the isotope molybdenum-99 (Mo-99), a precursor of the medically widely used technetium-99 m . To fill the gap in demand, the Australian Nuclear Science and Technology Organisation has now arranged with US company Lantheus Medical Imaging, Inc., a world leader in medical imaging, to supply Mo-99. Subject to pending Australian regulatory processes, the deal is expected to assist in alleviating the world's current nuclear medicine shortage. As ANSTO is currently also the only global commercial supplier that produces Mo-99 from low enriched uranium (LEU) targets, Lantheus will be the first company bringing LEU derived Tc-99 m to the US market. To date, over 95% of Mo-99 is derived from highly enriched uranium (HEU) targets. However, there are concerns regarding proliferation risks associated with HEU targets and for commercial uses production from LEU targets would be desirable. ANSTO says that global Mo-99 supply chain is fragile and limited and it is working closely with nuclear safety and healthy regulators, both domestically and overseas, to expedite all necessary approvals to allow long-term production and export of medical isotopes.

  14. Income-Based Disparities in Early Elementary School Science Achievement (United States)

    Curran, F. Chris


    This study documents gaps in kindergarten and first-grade science achievement by family income and explores the degree to which such gaps can be accounted for by student race/ethnicity, out-of-school activities, parental education, and school fixed effects. In doing so, it expands on prior research that documents disparate rates of science…

  15. Interacting black holes

    International Nuclear Information System (INIS)

    Costa, Miguel S.; Perry, Malcolm J.


    We revisit the geometry representing l collinear Schwarzschild black holes. It is seen that the black holes' horizons are deformed by their mutual gravitational attraction. The geometry has a string like conical singularity that connects the holes but has nevertheless a well defined action. Using standard gravitational thermodynamics techniques we determine the free energy for two black holes at fixed temperature and distance, their entropy and mutual force. When the black holes are far apart the results agree with Newtonian gravity expectations. This analyses is generalized to the case of charged black holes. Then we consider black holes embedded in string/M-theory as bound states of branes. Using the effective string description of these bound states and for large separation we reproduce exactly the semi-classical result for the entropy, including the correction associated with the interaction between the holes

  16. Astrophysical black holes

    CERN Document Server

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


    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.

  17. Reliability and Validity of "Invisible-Gap Filling" Items


    靜, 哲人


    The purpose of this study was to explore the potential of "invisible-gap filling" items primarily as an in-house achievement measure of reading-oriented courses and secondarily as a more general overall-ability measure. More specifically, it compared multiple-matching "invisible-gap filling" items and their "visible" counterparts in terms of item facility, item discrimination, test reliability, and test validity.Eighty-eight Japanese university 1st year students took a 25-item invisible-gap f...

  18. Effects of Cooperative Learning Teams on Student Achievement and Race Relations: Treatment by Race Interactions. (United States)

    Salvin, Robert E.; Oickle, Eileen


    Investigates differences between Black and White students with regard to improvement in academic achievement while working in small, heterogeneous learning teams. Findings indicated that Black students made disproportionately outstanding gains in academic achievement when participating in the team learning approach. (DB)

  19. Black branes as piezoelectrics. (United States)

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


    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.

  20. Naked black holes

    International Nuclear Information System (INIS)

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


    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

  1. Nonextremal stringy black hole

    International Nuclear Information System (INIS)

    Suzuki, K.


    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

  2. Where are LIGO's Big Black Holes? (United States)

    Fishbach, Maya; Holz, Daniel E.


    In LIGO's O1 and O2 observational runs, the detectors were sensitive to stellar mass binary black hole coalescences with component masses up to 100 M⊙, with binaries with primary masses above 40 M⊙ representing over 90% of the total accessible sensitive volume. Nonetheless, of the first 3.9 LIGO detections (GW150914, GW151226, GW170104, and LVT151012), the most massive binary detected was GW150914 with a primary component mass of ~ 36 M⊙ far below the detection mass limit. Furthermore, there are theoretical arguments in favor of an upper mass gap, predicting an absence of black holes in the mass range 50 constraints on the shape of the underlying mass distribution of LIGO's binary black holes. We fit a power-law distribution with an upper mass cutoff to real and simulated BBH mass measurements, finding that the first four detections favor shallow power law slopes α < 3 and an upper mass cutoff Mmax ~ 40 M⊙. We show that with ~10 additional LIGO BBH detections, fitting the BH mass distribution will provide strong evidence for an upper mass gap if one exists.

  3. Black holes as mirrors: quantum information in random subsystems

    International Nuclear Information System (INIS)

    Hayden, Patrick; Preskill, John


    We study information retrieval from evaporating black holes, assuming that the internal dynamics of a black hole is unitary and rapidly mixing, and assuming that the retriever has unlimited control over the emitted Hawking radiation. If the evaporation of the black hole has already proceeded past the ''half-way'' point, where half of the initial entropy has been radiated away, then additional quantum information deposited in the black hole is revealed in the Hawking radiation very rapidly. Information deposited prior to the half-way point remains concealed until the half-way point, and then emerges quickly. These conclusions hold because typical local quantum circuits are efficient encoders for quantum error-correcting codes that nearly achieve the capacity of the quantum erasure channel. Our estimate of a black hole's information retention time, based on speculative dynamical assumptions, is just barely compatible with the black hole complementarity hypothesis

  4. Filling the gaps

    DEFF Research Database (Denmark)

    Tota, Pasqua Marina


    ) with the main aim to achieve basic education for all children, youth and adults. A participant in this process since 2000 is the Global Campaign for Education (GCE), an advocacy network of INGOs, established jointly by Oxfam, ActionAid International, Education International and Global March Against Child Labour....... This article examines the role and impact of these advocacy INGOs in EFA, in terms of the structural conditions created by the current mode of ‘global governance’ in education. In its first section, this article draws a conceptual framework purported to illuminate the way transnational policy in education...

  5. Visual-Motor Test Performance: Race and Achievement Variables. (United States)

    Fuller, Gerald B.; Friedrich, Douglas


    Rural Black and White children of variant academic achievement were tested on the Minnesota Percepto-Diagnostic Test, which consists of six gestalt designs for the subject to copy. Analyses resulted only in a significant achievement effect; when intellectual level was statistically controlled, race was not a significant variable. (Editor/SJL)

  6. Measuring the Pros and Cons of What It Means to Be a Black Man: Development and Validation of the Black Men's Experiences Scale (BMES). (United States)

    Bowleg, Lisa; English, Devin; Del Rio-Gonzalez, Ana Maria; Burkholder, Gary J; Teti, Michelle; Tschann, Jeanne M


    Although extensive research documents that Black people in the U.S. frequently experience social discrimination, most of this research aggregates these experiences primarily or exclusively by race. Consequently, empirical gaps exist about the psychosocial costs and benefits of Black men's experiences at the intersection of race and gender. Informed by intersectionality, a theoretical framework that highlights how multiple social identities intersect to reflect interlocking social-structural inequality, this study addresses these gaps with the qualitative development and quantitative test of the Black Men's Experiences Scale (BMES). The BMES assesses Black men's negative experiences with overt discrimination and microaggressions, as well their positive evaluations of what it means to be Black men. First, we conducted focus groups and individual interviews with Black men to develop the BMES. Next, we tested the BMES with 578 predominantly low-income urban Black men between the ages of 18 and 44. Exploratory factor analysis suggested a 12-item, 3-factor solution that explained 63.7% of the variance. We labeled the subscales: Overt Discrimination, Microaggressions, and Positives: Black Men . Confirmatory factor analysis supported the three-factor solution. As hypothesized, the BMES's subscales correlated with measures of racial discrimination, depression, resilience, and social class at the neighborhood-level. Preliminary evidence suggests that the BMES is a reliable and valid measure of Black men's experiences at the intersection of race and gender.

  7. Measuring the Pros and Cons of What It Means to Be a Black Man: Development and Validation of the Black Men’s Experiences Scale (BMES) (United States)

    Bowleg, Lisa; English, Devin; del Rio-Gonzalez, Ana Maria; Burkholder, Gary J.; Teti, Michelle; Tschann, Jeanne M.


    Although extensive research documents that Black people in the U.S. frequently experience social discrimination, most of this research aggregates these experiences primarily or exclusively by race. Consequently, empirical gaps exist about the psychosocial costs and benefits of Black men’s experiences at the intersection of race and gender. Informed by intersectionality, a theoretical framework that highlights how multiple social identities intersect to reflect interlocking social-structural inequality, this study addresses these gaps with the qualitative development and quantitative test of the Black Men’s Experiences Scale (BMES). The BMES assesses Black men’s negative experiences with overt discrimination and microaggressions, as well their positive evaluations of what it means to be Black men. First, we conducted focus groups and individual interviews with Black men to develop the BMES. Next, we tested the BMES with 578 predominantly low-income urban Black men between the ages of 18 and 44. Exploratory factor analysis suggested a 12-item, 3-factor solution that explained 63.7% of the variance. We labeled the subscales: Overt Discrimination, Microaggressions, and Positives: Black Men. Confirmatory factor analysis supported the three-factor solution. As hypothesized, the BMES’s subscales correlated with measures of racial discrimination, depression, resilience, and social class at the neighborhood-level. Preliminary evidence suggests that the BMES is a reliable and valid measure of Black men’s experiences at the intersection of race and gender. PMID:27087786

  8. PhoneGap for enterprise

    CERN Document Server

    Shotts, Kerri


    This book is intended for developers who wish to use PhoneGap to develop useful, rich, secure mobile applications for their enterprise environment. The book assumes you have working knowledge of PhoneGap, HTML5, CSS3, and JavaScript, and a reasonable understanding of networking and n-tier architectures.

  9. LiGAPS-Beef 2018

    NARCIS (Netherlands)

    Linden, van der A.; Ven, van de G.W.J.; Oosting, S.J.; Ittersum, van M.K.; Boer, de I.J.M.


    LiGAPS-Beef is a mechanistic model to assess potential and feed-limited beef production in different beef production systems across the world. The model is one of the first using concepts of production ecology to simulate livestock production. LiGAPS-Beef consists of a thermoregulation sub-model, a

  10. LiGAPS-Beef 2017

    NARCIS (Netherlands)

    Linden, van der A.; Ven, van de G.W.J.; Oosting, S.J.; Ittersum, van M.K.; Boer, de I.J.M.


    LiGAPS-Beef is a mechanistic model to assess potential and feed-limited beef production in different beef production systems across the world. The model is one of the first using concepts of production ecology to simulate livestock production. LiGAPS-Beef consists of a thermoregulation sub-model, a

  11. False air-bone gap. (United States)

    Rudmin, F


    A single case is reported of a severely hearing-impaired child with a finding of a large air-bone gap on pure-tone audiometry on multiple tests. Exploratory surgery found normal middle ear function. Subsequent audiometry indicated the presence of a false air-bone gap resulting from vibrotactile responses. Test procedures for identifying vibrotactile responses are discussed.

  12. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are ...

  13. The Emissions Gap Report 2014

    DEFF Research Database (Denmark)

    Farrell, Timothy Clifford

    This fifth Emissions Gap report has a different focus from previous years. While it updates the 2020 emissions gap analysis, it gives particular attention to the implications of the global carbon dioxide emissions budget for staying within the 2 °C limit beyond 2020. It does so because countries ...

  14. Bridging the terahertz gap

    International Nuclear Information System (INIS)

    Davies, Giles; Linfield, Edmund


    Over the last century or so, physicists and engineers have progressively explored and conquered the electromagnetic spectrum. Starting with visible light, we have encroached outwards, developing techniques for generating and detecting radiation at both higher and lower frequencies. And as each successive region of the spectrum has been colonized, we have developed technology to exploit the radiation found there. X-rays, for example, are routinely used to image hidden objects. Near-infrared radiation is used in fibre-optic communications and in compact-disc players, while microwaves are used to transmit signals from your mobile phone. But there is one part of the electromagnetic spectrum that has steadfastly resisted our advances. This is the terahertz region, which ranges from frequencies of about 300 GHz to 10 THz (10 x 10 sup 1 sup 2 Hz). This corresponds to wavelengths of between about 1 and 0.03 mm, and lies between the microwave and infrared regions of the spectrum. However, the difficulties involved in making suitably compact terahertz sources and detectors has meant that this region of the spectrum has only begun to be explored thoroughly over the last decade. A particularly intriguing feature of terahertz radiation is that the semiconductor devices that generate radiation at frequencies above and below this range operate in completely different ways. At lower frequencies, microwaves and millimetre- waves can be generated by 'electronic' devices such as those found in mobile phones. At higher frequencies, near-infrared and visible light are generated by 'optical' devices such as semiconductor laser diodes, in which electrons emit light when they jump across the semiconductor band gap. Unfortunately, neither electronic nor optical devices can conveniently be made to work in the terahertz region because the terahertz frequency range sits between the electronic and optical regions of the electromagnetic spectrum. Developing a terahertz source is therefore a

  15. The fluctuating gap model

    International Nuclear Information System (INIS)

    Cao, Xiaobin


    The quasi-one-dimensional systems exhibit some unusual phenomenon, such as the Peierls instability, the pseudogap phenomena and the absence of a Fermi-Dirac distribution function line shape in the photoemission spectroscopy. Ever since the discovery of materials with highly anisotropic properties, it has been recognized that fluctuations play an important role above the three-dimensional phase transition. This regime where the precursor fluctuations are presented can be described by the so called fluctuating gap model (FGM) which was derived from the Froehlich Hamiltonian to study the low energy physics of the one-dimensional electron-phonon system. Not only is the FGM of great interest in the context of quasi-one-dimensional materials, liquid metal and spin waves above T c in ferromagnets, but also in the semiclassical approximation of superconductivity, it is possible to replace the original three-dimensional problem by a directional average over effectively one-dimensional problem which in the weak coupling limit is described by the FGM. In this work, we investigate the FGM in a wide temperature range with different statistics of the order parameter fluctuations. We derive a formally exact solution to this problem and calculate the density of states, the spectral function and the optical conductivity. In our calculation, we show that a Dyson singularity appears in the low energy density of states for Gaussian fluctuations in the commensurate case. In the incommensurate case, there is no such kind of singularity, and the zero frequency density of states varies differently as a function of the correlation lengths for different statistics of the order parameter fluctuations. Using the density of states we calculated with non-Gaussian order parameter fluctuations, we are able to calculate the static spin susceptibility which agrees with the experimental data very well. In the calculation of the spectral functions, we show that as the correlation increases, the quasi

  16. The fluctuating gap model

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Xiaobin


    The quasi-one-dimensional systems exhibit some unusual phenomenon, such as the Peierls instability, the pseudogap phenomena and the absence of a Fermi-Dirac distribution function line shape in the photoemission spectroscopy. Ever since the discovery of materials with highly anisotropic properties, it has been recognized that fluctuations play an important role above the three-dimensional phase transition. This regime where the precursor fluctuations are presented can be described by the so called fluctuating gap model (FGM) which was derived from the Froehlich Hamiltonian to study the low energy physics of the one-dimensional electron-phonon system. Not only is the FGM of great interest in the context of quasi-one-dimensional materials, liquid metal and spin waves above T{sub c} in ferromagnets, but also in the semiclassical approximation of superconductivity, it is possible to replace the original three-dimensional problem by a directional average over effectively one-dimensional problem which in the weak coupling limit is described by the FGM. In this work, we investigate the FGM in a wide temperature range with different statistics of the order parameter fluctuations. We derive a formally exact solution to this problem and calculate the density of states, the spectral function and the optical conductivity. In our calculation, we show that a Dyson singularity appears in the low energy density of states for Gaussian fluctuations in the commensurate case. In the incommensurate case, there is no such kind of singularity, and the zero frequency density of states varies differently as a function of the correlation lengths for different statistics of the order parameter fluctuations. Using the density of states we calculated with non-Gaussian order parameter fluctuations, we are able to calculate the static spin susceptibility which agrees with the experimental data very well. In the calculation of the spectral functions, we show that as the correlation increases, the

  17. Black holes are warm

    International Nuclear Information System (INIS)

    Ravndal, F.


    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)

  18. Black hole candidates

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Black hole candidates. In the case of X-ray sources such as Cyg X-1, the mass of the compact object inferred from combined optical and X-ray data, suggest M_compact object > 3.4 M_sun => Black Hole! A remarkable discovery!! Thus X-ray emitting binary systems ...

  19. Black hole Berry phase

    NARCIS (Netherlands)

    de Boer, J.; Papadodimas, K.; Verlinde, E.


    Supersymmetric black holes are characterized by a large number of degenerate ground states. We argue that these black holes, like other quantum mechanical systems with such a degeneracy, are subject to a phenomenon which is called the geometric or Berry’s phase: under adiabatic variations of the

  20. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm


    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)....

  1. Black hole levitron

    NARCIS (Netherlands)

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


    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

  2. Protecting Black Girls (United States)

    Morris, Monique W.


    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…

  3. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)


    Jan 27, 2016 ... In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of ...

  4. Black Boycott: Gainsville, Florida (United States)

    White, Arthur O.


    A case study of the events precipitating a black student boycott in 1969 in Gainesville, Flordia, when school board manuevering to avoid school integration led to the threatened closing of Lincoln High School, a reputable black community school. Also described are the subsequent transformations of Lincoln into a vocational-technical school and…

  5. Neoliberalism and Black Education. (United States)

    Rich, John Martin


    In contrast to traditional liberals, neoliberals share a commitment to greater economic risk-taking, support for entrepreneurism, a new industrial policy, and a different Federal Role. While New Deal and Great Society liberalism may have been more favorable to blacks, perhaps more balanced and equitable policies for blacks could be developed if…

  6. Lifshitz topological black holes

    International Nuclear Information System (INIS)

    Mann, R.B.


    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.

  7. Legitimizing Blacks in Philosophy

    Directory of Open Access Journals (Sweden)

    Jameliah Shorter-Bourhanou


    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.

  8. Analogue Hawking radiation from astrophysical black-hole accretion

    International Nuclear Information System (INIS)

    Das, Tapas K


    We show that spherical accretion onto astrophysical black holes can be considered as a natural example of an analogue system. We provide, for the first time, an exact analytical scheme for calculating the analogue Hawking temperature and surface gravity for general relativistic accretion onto astrophysical black holes. Our calculation may bridge the gap between the theory of transonic astrophysical accretion and the theory of analogue Hawking radiation. We show that the domination of the analogue Hawking temperature over the actual Hawking temperature may be a real astrophysical phenomenon, though observational tests of this fact will at best be difficult and at worst might prove to be impossible. We also discuss the possibilities of the emergence of analogue white holes around astrophysical black holes. Our calculation is general enough to accommodate accreting black holes with any mass

  9. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    as a star or dispersing altogether. Were we engineers with advanced technology, we might attempt to find that critical amount of energy necessary to form a black hole. However, despite some fears to the contrary, such technology does not exist, so instead we investigate this critical regime numerically. The first step is to pick ...

  10. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    denotes the partial derivatives of . The construction of a numerical method with which ... which configurations form black holes and which disperse (the only two options in this model). The problem in picturing such a space is that it is infinite ..... 4.1 The future: Less symmetry. The work described above all assumes spherical ...

  11. Gene circuit analysis of the terminal gap gene huckebein.

    Directory of Open Access Journals (Sweden)

    Maksat Ashyraliyev


    Full Text Available The early embryo of Drosophila melanogaster provides a powerful model system to study the role of genes in pattern formation. The gap gene network constitutes the first zygotic regulatory tier in the hierarchy of the segmentation genes involved in specifying the position of body segments. Here, we use an integrative, systems-level approach to investigate the regulatory effect of the terminal gap gene huckebein (hkb on gap gene expression. We present quantitative expression data for the Hkb protein, which enable us to include hkb in gap gene circuit models. Gap gene circuits are mathematical models of gene networks used as computational tools to extract regulatory information from spatial expression data. This is achieved by fitting the model to gap gene expression patterns, in order to obtain estimates for regulatory parameters which predict a specific network topology. We show how considering variability in the data combined with analysis of parameter determinability significantly improves the biological relevance and consistency of the approach. Our models are in agreement with earlier results, which they extend in two important respects: First, we show that Hkb is involved in the regulation of the posterior hunchback (hb domain, but does not have any other essential function. Specifically, Hkb is required for the anterior shift in the posterior border of this domain, which is now reproduced correctly in our models. Second, gap gene circuits presented here are able to reproduce mutants of terminal gap genes, while previously published models were unable to reproduce any null mutants correctly. As a consequence, our models now capture the expression dynamics of all posterior gap genes and some variational properties of the system correctly. This is an important step towards a better, quantitative understanding of the developmental and evolutionary dynamics of the gap gene network.

  12. Representation and Salary Gaps by Race-Ethnicity and Gender at Selective Public Universities (United States)

    Li, Diyi; Koedel, Cory


    We use data from 2015-2016 to document faculty representation and wage gaps by race-ethnicity and gender in six fields at selective public universities. Consistent with widely available information, Black, Hispanic, and female professors are underrepresented and White and Asian professors are overrepresented in our data. Disadvantaged minority and…

  13. Early-Life Origins of the Race Gap in Men's Mortality (United States)

    Warner, David F.; Hayward, Mark D.


    Using a life course framework, we examine the early life origins of the race gap in men's all-cause mortality. Using the National Longitudinal Survey of Older Men (1966-1990), we evaluate major social pathways by which early life conditions differentiate the mortality experiences of blacks and whites. Our findings indicate that early life…

  14. Impact of learning orientation on African American children's attitudes toward high-achieving peers. (United States)

    Marryshow, Derrick; Hurley, Eric A; Allen, Brenda A; Tyler, Kenneth M; Boykin, A Wade


    This study examined Ogbu's widely accepted thesis that African American students reject high academic achievement because they perceive its limited utility in a world where their upward mobility is constrained by racial discrimination. Boykin's psychosocial integrity model contends that Black students value high achievement but that discrepancies between their formative cultural experiences and those imposed in school lead them to reject the modes of achievement available in classrooms. Ninety Black children completed a measure of attitudes toward students who achieve via mainstream or African American cultural values. Participants rejected the mainstream achievers and embraced the African American cultural achievers. Moreover, they expected their teachers to embrace the mainstream achievers and reject those who achieved through high-verve behavior. Results suggest that Boykin's thesis is a needed refinement to Ogbu's ideas. They indicate that Black children may reject not high achievement but some of the mainstream cultural values and behaviors on which success in mainstream classrooms is made contingent.

  15. A Capstone Project Using the Gap Analysis Model: Closing the College Readiness Gap for Latino English Language Learners with a Focus on School Support and School Counseling Resources (United States)

    Jimenez, Evelyn


    This capstone project applied Clark and Estes' (2008) gap analysis framework to identify performance gaps, develop perceived root causes, validate the causes, and formulate research-based solutions to present to Trojan High School. The purpose was to examine ways to increase the academic achievement of ELL students, specifically Latinos, by…


    International Nuclear Information System (INIS)

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


    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


    International Nuclear Information System (INIS)



    Since the RHIC Au-Au run in the year 2001 the 200 MHz cavity system was used at storage and a 28 MHz system during injection and acceleration. The rebucketing procedure potentially causes a higher debunching rate of heavy ion beams in addition to amplifying debunching due to other mechanisms. At the end of a four hour store, debunched beam can easily account for more than 50% of the total beam intensity. This effect is even stronger with the achieved high intensities of the RHIC Au-Au run in 2004. A beam abort at the presence of a lot of debunched beam bears the risk of magnet quenching and experimental detector damage due to uncontrolled beam losses. Thus it is desirable to avoid any accumulation of debunched beam from the beginning of each store, in particular to anticipate cases of unscheduled beam aborts due to a system failure. A combination of a fast transverse kickers and the new 2-stage copper collimator system are used to clean the abort gap continuously throughout the store with a repetition rate of 1 Hz. This report gives. an overview of the new gap cleaning procedure and the achieved performance

  18. Gap Surface Plasmon Waveguide Analysis

    DEFF Research Database (Denmark)

    Nielsen, Michael Grøndahl; Bozhevolnyi, Sergey I.


    Plasmonic waveguides supporting gap surface plasmons (GSPs) localized in a dielectric spacer between metal films are investigated numerically and the waveguiding properties at telecommunication wavelengths are presented. Especially, we emphasize that the mode confinement can advantageously be con...

  19. Closing the Cybersecurity Skills Gap

    Directory of Open Access Journals (Sweden)

    Rebecca Vogel


    Full Text Available The current consensus is that there is a worldwide gap in skills needed for a competent cybersecurity workforce. This skills gap has implications for the national security sector, both public and private. Although the view is that this will take a concerted effort to rectify, it presents an opportunity for IT professionals, university students, and aspirants to take-up jobs in national security national intelligence as well military and law enforcement intelligence. This paper examines context of the issue, the nature of the cybersecurity skills gap, and some key responses by governments to address the problem. The paper also examines the emerging employment trends, some of the employment challenges, and what these might mean for practice. The paper argues that the imperative is to close the cyber skills gap by taking advantage of the window of opportunity, allowing individuals interested in moving into the cybersecurity field to do so via education and training.

  20. "Black Like Me": Reframing Blackness for Decolonial Politics (United States)

    Dei, George J. Sefa


    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,…

  1. Customizing Laboratory Information Systems: Closing the Functionality Gap. (United States)

    Gershkovich, Peter; Sinard, John H


    Highly customizable laboratory information systems help to address great variations in laboratory workflows, typical in Pathology. Often, however, built-in customization tools are not sufficient to add all of the desired functionality and improve systems interoperability. Emerging technologies and advances in medicine often create a void in functionality that we call a functionality gap. These gaps have distinct characteristics—a persuasive need to change the way a pathology group operates, the general availability of technology to address the missing functionality, the absence of this technology from your laboratory information system, and inability of built-in customization tools to address it. We emphasize the pervasive nature of these gaps, the role of pathology informatics in closing them, and suggest methods on how to achieve that. We found that a large number of the papers in the Journal of Pathology Informatics are concerned with these functionality gaps, and an even larger proportion of electronic posters and abstracts presented at the Pathology Informatics Summit conference each year deal directly with these unmet needs in pathology practice. A rapid, continuous, and sustainable approach to closing these gaps is critical for Pathology to provide the highest quality of care, adopt new technologies, and meet regulatory and financial challenges. The key element of successfully addressing functionality gaps is gap ownership—the ability to control the entire pathology information infrastructure with access to complementary systems and components. In addition, software developers with detailed domain expertise, equipped with right tools and methodology can effectively address these needs as they emerge.

  2. Closing the Racial Discipline Gap in Classrooms by Changing Teacher Practice (United States)

    Gregory, Anne; Hafen, Christopher A.; Ruzek, Erik; Mikami, Amori Yee; Allen, Joseph P.; Pianta, Robert C.


    Black students are issued school discipline sanctions at rates higher than members of other racial and ethnic groups, underscoring the need for professional development that addresses this gap. In 86 secondary classrooms, a randomized controlled trial examined the effects of a 2-year teacher coaching program, My Teaching Partner Secondary (MTP-S). Results from the second year of coaching and the year after coaching was discontinued replicated previous findings from the first year of coaching—intervention teachers had no significant disparities in discipline referral between Black students and their classmates, compared to teachers in the control condition, for whom racial discipline gaps remained. Thus, MTP-S effects were replicated in the second year of coaching and maintained when coaching was withdrawn. Mediational analyses identified mechanisms for these effects; Black students had a low probability of receiving disciplinary referrals with teachers who increased skills to engage students in high-level analysis and inquiry. PMID:28190913

  3. Chandra X-ray constraints on the candidate Ca-rich gap transient SN 2016hnk (United States)

    Sell, P. H.; Arur, K.; Maccarone, T. J.; Kotak, R.; Knigge, C.; Sand, D. J.; Valenti, S.


    We present a Chandra observation of SN 2016hnk, a candidate Ca-rich gap transient. This observation was specifically designed to test whether or not this transient was the result of the tidal detonation of a white dwarf by an intermediate-mass black hole. Since we detect no X-ray emission 28 d after the discovery of the transient, as predicted from fall-back accretion, we rule out this model. Our upper limit of ˜10 M⊙ does not allow us to rule out a neutron star or stellar-mass black hole detonator due limits on the sensitivity of Chandra to soft X-rays and unconstrained variables tied to the structure of super-Eddington accretion discs. Together with other Chandra and multiwavelength observations, our analysis strongly argues against the intermediate-mass black hole tidal detonation scenario for Ca-rich gap transients more generally.

  4. The Detection and Parameter Estimation of Binary Black Hole Mergers (United States)

    Biwer, Christopher M.

    In this dissertation we study gravitational-wave data analysis techniques for binary neutron star and black hole mergers. During its first observing run, the Advanced Laser Interferometer Gravitational-wave Observatory (Advanced LIGO) reported the first, direct observations of gravitational waves from two binary black hole mergers. We present the results from the search for binary black hole mergers which unambiguously detected the binary black hole mergers. We determine the effect of calibration errors on the detection statistic of the search. Since the search is not designed to precisely measure the astrophysical parameters of the binary neutron star and black hole mergers, we use Bayesian methods to develop a new parameter estimation analysis. We demonstrate the performance of the analysis on the binary black hole mergers detected during Advanced LIGO's first observing run. We use the parameter estimation analysis to assess the ability of gravitational-wave observatories to observe a gap in the black hole mass distribution between 52 M and 133 M due to pair-instability supernovae. Finally, we use simulated signals added to the Advanced LIGO detectors to validate the search and parameter estimation analyses used to publish the detection of the astrophysical events.

  5. Black phosphorus saturable absorber for ultrashort pulse generation

    Energy Technology Data Exchange (ETDEWEB)

    Sotor, J., E-mail:; Sobon, G.; Abramski, K. M. [Laser and Fiber Electronics Group, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370 (Poland); Macherzynski, W.; Paletko, P. [Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, Wroclaw 50-372 (Poland)


    Low-dimensional materials, due to their unique and versatile properties, are very interesting for numerous applications in electronics and optoelectronics. Recently rediscovered black phosphorus, with a graphite-like layered structure, can be effectively exfoliated up to the single atomic layer called phosphorene. Contrary to graphene, it possesses a direct band gap controllable by the number of stacked atomic layers. For those reasons, black phosphorus is now intensively investigated and can complement or replace graphene in various photonics and electronics applications. Here, we demonstrate that black phosphorus can serve as a broadband saturable absorber and can be used for ultrashort optical pulse generation. The mechanically exfoliated ∼300 nm thick layers of black phosphorus were transferred onto the fiber core, and under pulsed excitation at 1560 nm wavelength, its transmission increases by 4.6%. We have demonstrated that the saturable absorption of black phosphorus is polarization sensitive. The fabricated device was used to mode-lock an Er-doped fiber laser. The generated optical solitons with the 10.2 nm bandwidth and 272 fs duration were centered at 1550 nm. The obtained results unambiguously show that black phosphorus can be effectively used for ultrashort pulse generation with performances similar or even better than currently used graphene or carbon nanotubes. This application of black phosphorus proves its great potential to future practical use in photonics.

  6. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan


    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

  7. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)


    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  8. Verb gapping: an action-gap compatibility study. (United States)

    Claus, Berry


    This study addresses the processing of verb-gapping sentences, e.g., John closes a juice bottle and Jim [ ] a lemonade bottle. The goal was to explore if there would be an interaction between language comprehension and motor action not only for overt action verbs but also for gapped verbs. Participants read gapping sentences that either described clockwise or counter-clockwise manual rotations (e.g., closes vs. opens a juice bottle). Adopting a paradigm developed by Zwaan and Taylor (2006), sentence presentation was frame-by-frame. Participants proceeded from frame to frame by turning a knob either clockwise or counter clockwise. Analyses of the frame reading-times yielded a significant effect of compatibility between the linguistically conveyed action and the knob turning for the overt-verb (e.g., closes/opens a juice bottle) as well as for the gapped-verb frame (e.g., a lemonade bottle) - with longer reading times in the match condition than in the mismatch condition - but not for any of the other frames (e.g., and Jim). The results are promising in providing novel evidence for the real-time reactivation of gapped verbs and in suggesting that action simulation is not bound to the processing of overt verbs. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Exploring cross-national differences in gender gaps in education

    NARCIS (Netherlands)

    Langen, A.M.L. van; Bosker, R.J.; Dekkers, H.P.J.M.


    Although the participation rates of females in science, technology, engineering, and mathematics (or STEM) education is poor in most Western countries, considerable differences across countries exist as well. This may be due to differences in the so-called gender achievement gaps, that is, delays of

  10. The Challenge of Gender Gap in Science and Technology Among ...

    African Journals Online (AJOL)

    One of the challenges of university education in Nigeria is the issue of gender imbalance in the choice of pure science and technology courses. While private universities have contributed immensely in narrowing the gap between male and female students in over all admission, much is yet to be achieved in the area of pure ...

  11. Strain sensitivity of band gaps of Sn-containing semiconductors

    DEFF Research Database (Denmark)

    Li, Hong; Castelli, Ivano Eligio; Thygesen, Kristian Sommer


    Tuning of band gaps of semiconductors is a way to optimize materials for applications within photovoltaics or as photocatalysts. One way to achieve this is through applying strain to the materials. We investigate the effect of strain on a range of Sn-containing semiconductors using density...

  12. Urban-Rural Excellence Gaps: Features, Factors, and Implications (United States)

    Hernández-Torrano, Daniel


    The purpose of this study was to examine the presence of excellence gaps (i.e., differences between subgroups of students performing at the highest levels of achievement) in a sample of 563 students nominated as gifted by their teachers in urban, semi-urban, and rural settings in Spain. In general, the results suggested the existence of excellence…

  13. A Critical Policy Analysis of Texas' "Closing the Gaps 2015" (United States)

    Mansfield, Katherine Cumings; Thackik, Stefani Leigh


    This critical policy analysis uses critical race theory to provide a counter narrative to the P-16 initiative in Texas known as "Closing the Gaps 2015". Findings indicate that while these reforms aim to increase educational access and achievement for people of color, they fall short of addressing systemic inequities such as enduring…

  14. Stereotype Threat and the Gender Gap in Political Knowledge (United States)

    McGlone, Matthew S.; Aronson, Joshua; Kobrynowicz, Diane


    Men tend to achieve higher response accuracy than women on surveys of political knowledge. We investigated the possibility that this performance gap is moderated by factors that render the communicative context of a survey intellectually threatening to women and thereby induce stereotype threat. In a telephone survey of college students' political…

  15. Understanding the Black Aesthetic Experience. (United States)

    Curtis, Marvin V.


    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…

  16. The Thermodynamics of Black Holes

    Directory of Open Access Journals (Sweden)

    Wald Robert M.


    Full Text Available We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  17. Black Writers' Views of America. (United States)

    Hairston, Loyle


    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)

  18. Ethnic Differences in Alcohol Use: A Comparison of Black and White College Students in a Small Private University Setting (United States)

    Gover, Kristie S.


    An identified gap in the literature associated with college student alcohol use is the exploration of the problem based on ethnicity, specifically possible differences in use between Black and White college students. The purpose of the present study was to examine differences in alcohol use for Black and White college students at a small private…

  19. The theory of optical black hole lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gaona-Reyes, José L., E-mail:; Bermudez, David, E-mail:


    The event horizon of black holes and white holes can be achieved in the context of analogue gravity. It was proven for a sonic case that if these two horizons are close to each other their dynamics resemble a laser, a black hole laser, where the analogue of Hawking radiation is trapped and amplified. Optical analogues are also very successful and a similar system can be achieved there. In this work we develop the theory of optical black hole lasers and prove that the amplification is also possible. Then, we study the optical system by determining the forward propagation of modes, obtaining an approximation for the phase difference which governs the amplification, and performing numerical simulations of the pulse propagation of our system. - Highlights: • We develop the conditions to obtain the kinematics of the optical black hole laser. • We prove the amplification of Hawking radiation for the optical case. • We derive the forward propagation of modes and check the result of the backward case. • A model is proposed to calculate the phase difference and the amplification rate. • We perform numerical simulations of a pulse between two solitons forming a cavity.

  20. Employment gains and wage declines: the erosion of black women's relative wages since 1980. (United States)

    Pettit, Becky; Ewert, Stephanie


    Public policy initiatives in the 1950s and 1960s, including Affirmative Action and Equal Employment Opportunity law, helped mitigate explicit discrimination in pay, and the expansion of higher education and training programs have advanced the employment fortunes of many American women. By the early 1980s, some scholars proclaimed near equity in pay between black and white women, particularly among young and highly skilled workers. More recent policy initiatives and labor market conditions have been arguably less progressive for black women's employment and earnings: through the 1980s, 1990s, and the first half of the 2000s, the wage gap between black and white women widened considerably. Using data from the Current Population Survey Merged Outgoing Rotation Group (CPS-MORG), this article documents the racial wage gap among women in the United States from 1979 to 2005. We investigate how demographic and labor market conditions influence employment and wage inequality among black and white women over the period. Although shifts in labor supply influence the magnitude of the black-white wage gap among women, structural disadvantages faced by black women help explain the growth in the racial wage gap.

  1. Introducing the Black Hole (United States)

    Ruffini, Remo; Wheeler, John A.


    discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

  2. Colliding black hole solution

    International Nuclear Information System (INIS)

    Ahmed, Mainuddin


    A new solution of Einstein equation in general relativity is found. This solution solves an outstanding problem of thermodynamics and black hole physics. Also this work appears to conclude the interpretation of NUT spacetime. (author)

  3. 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.


    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

  4. Black Teenage Pregnancy

    Directory of Open Access Journals (Sweden)

    Loretta I. Winters


    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. Illuminating black holes (United States)

    Barr, Ian A.; Bull, Anne; O'Brien, Eileen; Drillsma-Milgrom, Katy A.; Milgrom, Lionel R.


    Two-dimensional shadows formed by illuminating vortices are shown to be visually analogous to the gravitational action of black holes on light and surrounding matter. They could be useful teaching aids demonstrating some of the consequences of general relativity.

  6. Black holes with halos (United States)

    Monten, Ruben; Toldo, Chiara


    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.

  7. Black Friday = Broget Branding?

    DEFF Research Database (Denmark)

    Hansen, Heidi


    Black Friday er et godt eksempel på, hvordan ikke kun produktbrands og corporate brands rejser på tværs af landegrænser, men også traditioner som Halloween, Valentines Day og i dette tilfælde den ultimative tilbuds-fredag, som i USA går under navnet Black Friday. Men hvad er Black Friday i Danmark......? Essensen ved Black Friday er lave priser, og det er der ved første øjekast ikke mange brandingmuligheder forbundet ved, hvis man forstår branding som en måde at skabe ekstra værdi omkring sit produkt eller sin virksomhed. Som brand bliver man dog alligevel nødt til at forholde sig til konceptet, da det er...

  8. Patterns of Black Excellence. Ethics and Public Policy Reprint 5. (United States)

    Sowell, Thomas

    The history of the advancement of blacks in the United States is almost a laboratory study of human achievement. But the story of how millions of people developed from the depths of slavery--acquired work skills, personal discipline, human ideals, and the whole complex of knowledge and values required for achievement in a modern society--is a…

  9. Is There a Gap in the Gap? Regional Differences in the Gender Pay Gap


    Hirsch, Boris; König, Marion; Möller, Joachim


    In this paper, we investigate regional differences in the gender pay gap both theoretically and empirically. Within a spatial oligopsony model, we show that more densely populated labour markets are more competitive and constrain employers' ability to discriminate against women. Utilising a large administrative data set for western Germany and a flexible semi-parametric propensity score matching approach, we find that the unexplained gender pay gap for young workers is substantially lower in ...

  10. Mobilizing Black America (United States)


    and financially for childbirth or parenting. - Adolescent Pregnancy Black female teenagers 15 to 19 years old were 140 percent more likely to have a...on adolescent pregnancy teenage sexual activity, and federally funded programs prevention. NATIONAL INSTITUTE OF CHILD HEALTH AND HUMAN DEVELOPMENT...communities? o Access to Health Care: Does everyone have equal access? o Poverty o Racism o Health Insurance o Black Physicians o Summary o Infant Mortality

  11. Black chrome outgassing study

    International Nuclear Information System (INIS)

    Beat, T.


    This report covers why black chrome is of interest, why its outgassing is relevant, how the study was conducted, examples of resultant data, and a conclusion. Black chrome is of interest in several areas of activity. Vacuum outgassing characteristics must be known to establish the pumping speed requirements. How much gas is evolved determines the pump speed required. The species of gas evolved determines the type of pump. The outgassing characteristics must be known to determine needed precleaning steps

  12. Quantum black holes

    International Nuclear Information System (INIS)

    't Hooft, G.


    No particle theory can be complete without gravity. Einstein's theory of gravity is of the Euler-Lagrange form, but standard quantization procedure fails. In quantum gravity the higher order interactions have a dimensionality different form the fundamental ones, because Newton's constant G has dimensions and the renormalization procedure fails. Another problem with quantum gravity is even more mysterious. Suppose that we had regularized the gravitational forces at the small distance end in the way that the weak intermediate vector boson regularized the fundamental 4-fermion interaction vertex of the weak interactions. Then what we discover is that the gravitational forces are unstable. Given sufficiently large amount of matter, it can collapse under its own weight. Classical general relativity tells us what will happen: a black hole is formed. But how is this formulated in quantum theory. S. Hawking observed that when a field theory is quantized in the background metric of a black hole, the black hole actually emits particles in a completely random thermal way. Apparently black holes are just another form of matter unstable against Hawking decay. Unfortunately this picture cannot be complete. The problem is that the quantum version of black holes has infinite phase space, and other symptoms of a run-away solution. Black holes are the heaviest and most compact forms of matter that can be imagined. A complete particle theory can have nothing but a spectrum of black-hole like objects at it high-energy end. This is why it is believed that a resolution of the black hole problem will in time disclose the complete small-distance structure of our world. 6 references

  13. Promoting Achievement for African American Males through Group Work (United States)

    Bailey, Deryl F.; Bradbury-Bailey, Mary E.


    The authors describe how the effective use of groups can promote academic achievement for adolescent African American males. Literature regarding adolescents' and African Americans' experience with groups is reviewed. The authors provide information on academic disidentification and achievement gaps, both critical to understanding the problem of…

  14. Are Teachers Responsible for Low Achievement by Poor Students? (United States)

    Berliner, David C.


    Backers of the No Child Left Behind (NCLB) law based their support on the belief that teachers and administrators primarily were responsible for low levels of achievement by America's poor. This one-sided view about who is responsible for the nation's achievement gap is both inadequate and unsupported by the evidence. The author argues that harsh…

  15. Immigrant Students' Achievements in Croatia, Serbia and Slovenia in Context (United States)

    Šori, Iztok; Šušteric, Nika; Gaber, Slavko


    Achievement gaps between immigrant and native students indicate failure to assure educational equity in the majority of countries assessed by the Programme for International Student Assessment in 2009 (PISA, 2009). The present article explains disparate achievement results in Europe, first testing the hypothesis of old and new democracies. In…

  16. Causticizing for Black Liquor Gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Scott Sinquefeld; James Cantrell; Xiaoyan Zeng; Alan Ball; Jeff Empie


    The cost-benefit outlook of black liquor gasification (BLG) could be greatly improved if the smelt causticization step could be achieved in situ during the gasification step. Or, at a minimum, the increase in causticizing load associated with BLG could be mitigated. A number of chemistries have been proven successful during black liquor combustion. In this project, three in situ causticizing processes (titanate, manganate, and borate) were evaluated under conditions suitable for high temperature entrained flow BLG, and low temperature steam reforming of black liquor. The evaluation included both thermodynamic modeling and lab experimentation. Titanate and manganate were tested for complete direct causticizing (to thus eliminate the lime cycle), and borates were evaluated for partial causticizing (to mitigate the load increase associated with BLG). Criteria included high carbonate conversion, corresponding hydroxide recovery upon hydrolysis, non process element (NPE) removal, and economics. Of the six cases (three chemistries at two BLG conditions), only two were found to be industrially viable: titanates for complete causticizing during high temperature BLG, and borates for partial causticizing during high temperature BLG. These two cases were evaluated for integration into a gasification-based recovery island. The Larsen [28] BLG cost-benefit study was used as a reference case for economic forecasting (i.e. a 1500 tpd pulp mill using BLG and upgrading the lime cycle). By comparison, using the titanate direct causticizing process yielded a net present value (NPV) of $25M over the NPV of BLG with conventional lime cycle. Using the existing lime cycle plus borate autocausticizing for extra capacity yielded a NPV of $16M.

  17. Charged Galileon black holes

    International Nuclear Information System (INIS)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar


    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory

  18. Black holes are neither particle accelerators nor dark matter probes. (United States)

    McWilliams, Sean T


    It has been suggested that maximally spinning black holes can serve as particle accelerators, reaching arbitrarily high center-of-mass energies. Despite several objections regarding the practical achievability of such high energies, and demonstrations past and present that such large energies could never reach a distant observer, interest in this problem has remained substantial. We show that, unfortunately, a maximally spinning black hole can never serve as a probe of high energy collisions, even in principle and despite the correctness of the original diverging energy calculation. Black holes can indeed facilitate dark matter annihilation, but the most energetic photons can carry little more than the rest energy of the dark matter particles to a distant observer, and those photons are actually generated relatively far from the black hole where relativistic effects are negligible. Therefore, any strong gravitational potential could probe dark matter equally well, and an appeal to black holes for facilitating such collisions is unnecessary.

  19. Gender, race & the veteran wage gap. (United States)

    Vick, Brandon; Fontanella, Gabrielle


    This paper analyzes earnings outcomes of Iraq/Afghanistan-era veterans. We utilize the 2009-2013 American Community Survey and a worker-matching methodology to decompose wage differences between veteran and non-veteran workers. Among fully-employed, 25-40 year-olds, veteran workers make 3% less than non-veteran workers. While male veterans make 9% less than non-veterans, female and black veterans experience a wage premium (2% and 7% respectively). Decomposition of the earnings gap identifies some of its sources. Relatively higher rates of disability and lower rates of educational attainment serve to increase the overall wage penalty against veterans. However, veterans work less in low-paying occupations than non-veterans, serving to reduce the wage penalty. Finally, among male and white subgroups, non-veterans earn more in the top quintile due largely to having higher educational attainment and greater representation in higher-paying occupations, such as management. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Determining the ’Gap (United States)


    of social scientists such as Robert Black, Richard Beckhard , and many others who began to study organizations, how they change, and how they adapt.20...Monograph, Fort Leavenworth: School of Advanced Military Studies, United States Army Command and General Staff College, 1996. Swain, Richard M

  1. A Quick Reference on Anion Gap and Strong Ion Gap. (United States)

    Torrente Artero, Carlos


    Metabolic acid-base disorders are common in emergency and critically ill patients. Clinicians may have difficulty recognizing their presence when multiple acid-base derangements are present in a single patient simultaneously. The anion gap and the strong ion gap concepts are useful calculations to identify the components of complex metabolic acid-base associated to the presence of unmeasured anions. This article presents their definition, normal values, indications, limitations, and guidelines for interpretation of changes in the clinical setting. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. The Gamma Gap and All-Cause Mortality.

    Directory of Open Access Journals (Sweden)

    Stephen P Juraschek

    Full Text Available The difference between total serum protein and albumin, i.e. the gamma gap, is a frequently used clinical screening measure for both latent infection and malignancy. However, there are no studies defining a positive gamma gap. Further, whether it is an independent risk factor of mortality is unknown.This study examined the association between gamma gap, all-cause mortality, and specific causes of death (cardiovascular, cancer, pulmonary, or other in 12,260 participants of the National Health and Nutrition Examination Survey (NHANES from 1999-2004. Participants had a comprehensive metabolic panel measured, which was linked with vital status data from the National Death Index. Cause of death was based on ICD10 codes from death certificates. Analyses were performed with Cox proportional hazards models adjusted for mortality risk factors. The mean (SE age was 46 (0.3 years and the mean gamma gap was 3.0 (0.01 g/dl. The population was 52% women and 10% black. During a median follow-up period of 4.8 years (IQR: 3.3 to 6.2 years, there were 723 deaths. The unadjusted 5-year cumulative incidences across quartiles of the gamma gap (1.7-2.7, 2.8-3.0, 3.1-3.2, and 3.3-7.9 g/dl were 5.7%, 4.2%, 5.5%, and 7.8%. After adjustment for risk factors, participants with a gamma gap of ≥3.1 g/dl had a 30% higher risk of death compared to participants with a gamma gap <3.1 g/dl (HR: 1.30; 95%CI: 1.08, 1.55; P = 0.006. Gamma gap (per 1.0 g/dl was most strongly associated with death from pulmonary causes (HR 2.22; 95%CI: 1.19, 4.17; P = 0.01.The gamma gap is an independent risk factor for all-cause mortality at values as low as 3.1 g/dl (in contrast to the traditional definition of 4.0 g/dl, and is strongly associated with death from pulmonary causes. Future studies should examine the biologic pathways underlying these associations.

  3. Winter Responses of Forest Birds to Habitat Corridors and Gaps

    Directory of Open Access Journals (Sweden)

    Colleen Cassady St. Clair


    Full Text Available Forest fragmentation and habitat loss may disrupt the movement or dispersal of forest-dwelling birds. Despite much interest in the severity of these effects and ways of mitigating them, little is known about actual movement patterns in different habitat types. We studied the movement of wintering resident birds, lured by playbacks of mobbing calls, to compare the willingness of forest birds to travel various distances in continuous forest, along narrow corridors (fencerows, and across gaps in forest cover. We also quantified the willingness of Black-capped Chickadees (Poecile atricapillus to cross gaps when alternative forested detour routes were available. All species were less likely to respond to the calls as distance increased to 200 m, although White-breasted Nuthatches (Sitta carolinensis and Hairy Woodpeckers (Picoides villosus were generally less likely to respond than chickadees and Downy Woodpeckers (P. pubescens. Chickadees were as likely to travel in corridors as in continuous forest, but were less likely to cross gaps as the gap distance increased. The other species were less willing to travel in corridors and gaps relative to forest, and the differences among habitats also increased with distance. For chickadees, gap-crossing decisions in the presence of forested detours varied over the range of distances that we tested, and were primarily influenced by detour efficiency (the length of the shortcut relative to the available detour. Over short distances, birds used forested detours, regardless of their efficiency. As absolute distances increased, birds tended to employ larger shortcuts in the open when detour efficiency was low or initial distance in the open was high, but they limited their distance from the nearest forest edge to 25 m. Thus, chickadees were unwilling to cross gaps of > 50 m when they had forested alternatives, yet they sometimes crossed gaps as large as 200 m when no such choice existed. Our results suggest that

  4. Clinical outcome of increased flexion gap after total knee arthroplasty. Can controlled gap imbalance improve knee flexion? (United States)

    Ismailidis, P; Kuster, M S; Jost, B; Giesinger, K; Behrend, H


    Increased range of motion (ROM) while maintaining joint stability is the goal of modern total knee arthroplasty (TKA). A biomechanical study has shown that small increases in flexion gap result in decreased tibiofemoral force beyond 90° flexion. The purpose of this paper was to investigate clinical implications of controlled increased flexion gap. Four hundred and four TKAs were allocated into one of two groups and analysed retrospectively. In the first group (n = 352), flexion gap exceeded extension gap by 2.5 mm, while in the second group (n = 52) flexion gap was equal to the extension gap. The procedures were performed from 2008 to 2012. The patients were reviewed 12 months postoperatively. Objective clinical results were assessed for ROM, mediolateral and sagittal stability. Patient-reported outcome measures were the WOMAC score and the Forgotten Joint Score (FJS-12). After categorizing postoperative flexion into three groups (poor < 90°, satisfactory 91°-119°, good ≥ 120°) significantly more patients in group 1 achieved satisfactory or good ROM (p = 0.006). Group 1 also showed a significantly higher mean FJS-12 (group 1: 73, group 2: 61, p = 0.02). The mean WOMAC score was 11 in the first and 14 in the second group (n.s.). Increase in flexion gap did not influence knee stability. The clinical relevance of this study is that a controlled flexion gap increase of 2.5 mm may have a positive effect on postoperative flexion and patient satisfaction after TKA. Neither knee stability in the coronal and sagittal planes nor complications were influenced by a controlled increase in flexion gap. III.

  5. Eternal and Evanescent Black Holes: It's All Done With Mirrors


    Good, Michael R. R.; Linder, Eric V.


    The analogy between black hole radiation and accelerating mirror radiation (the dynamical Casimir effect) is particularly strong for mirror trajectories giving rise to a constant thermal flux of particles. We present new ways to achieve such thermal plateaus, and customize their finite, semi-infinite, and eternal presence, corresponding to forming/collapsing, complete-evaporation/remnants, and eternal black holes. We find simple expressions for the energy flux in terms of the mirror rapidity ...

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

    International Nuclear Information System (INIS)

    Frolov, Valeri P.; Goswami, Rituparno


    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

  7. Opening complete band gaps in two dimensional locally resonant phononic crystals (United States)

    Zhou, Xiaoling; Wang, Longqi


    Locally resonant phononic crystals (LRPCs) which have low frequency band gaps attract a growing attention in both scientific and engineering field recently. Wide complete locally resonant band gaps are the goal for researchers. In this paper, complete band gaps are achieved by carefully designing the geometrical properties of the inclusions in two dimensional LRPCs. The band structures and mechanisms of different types of models are investigated by the finite element method. The translational vibration patterns in both the in-plane and out-of-plane directions contribute to the full band gaps. The frequency response of the finite periodic structures demonstrate the attenuation effects in the complete band gaps. Moreover, it is found that the complete band gaps can be further widened and lowered by increasing the height of the inclusions. The tunable properties by changing the geometrical parameters provide a good way to open wide locally resonant band gaps.


    Directory of Open Access Journals (Sweden)

    Gherai Dana Simona


    Full Text Available Theme – It is know that the large public and auditors hold different beliefs about the auditors’ duties and responsibilities. In this conditions audit expectation gap represents that level of expectation that remains uncovered. In this study paper, audit expectation gap represents the difference between the achievements of public auditors and the expectations that general public (students have beyond those responsibility. Purpose – The evolution of audit expectation gap has been examined in various countries, but the extent of the concept has not been investigated so much in public area. This study attempts to assess the perceptions of possible future auditors, students, regarding the existence of expectation gap in public area. Literature review – A review of the literature identifies many researches who define the concept since was given the first definition of audit expectation gap as the difference between the levels of expected performance and the results that auditors give, but just a few analysis the public area using students’ knowledge to understand the perception of future users of accounting information or potential bidders of accounting information. Methodology – This paper represents the beginning of a broader study that will be part of the doctoral thesis entitled “Organization and exercise of public audit in Romania”, started in 2009 at University Babes Bolyai from Cluj Napoca, coordinated by PhD Professor Matis Dumitru. The aim of this paper is to explore the findings of an empirical study, made on 352 students, were the primary data used were obtained through a questionnaire technique regarding the audit expectation gap in the public sector in Romania, looking into future to obtain responses using a larger respondent group. Findings – A reasonableness gap was uncovered, there is a gap between the expectation of students regarding the public auditors' profession and their results and there are differences

  9. Black hole physics. Black hole lightning due to particle acceleration at subhorizon scales. (United States)

    Aleksić, J; Ansoldi, S; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; Becerra González, J; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; de Oña Wilhelmi, E; Delgado Mendez, C; Dominis Prester, D; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; García López, R J; Garczarczyk, M; Garrido Terrats, D; Gaug, M; Godinović, N; González Muñoz, A; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Prada Moroni, P G; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Rodriguez Garcia, J; Rügamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzić, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Zanin, R; Kadler, M; Schulz, R; Ros, E; Bach, U; Krauß, F; Wilms, J


    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet. Copyright © 2014, American Association for the Advancement of Science.

  10. Black Sea Energy Security - Present and Future

    Directory of Open Access Journals (Sweden)

    Florinel Iftode


    Full Text Available We chose this theme to highlight the need for continuous and sustained human society to secure energy resources needed to survive, needs reflected in an increasingly in recent years in the strategies adopted at both states, as at the level of international organizations. Achieving security and stability in the wider Black Sea area has been among the priorities of each country's interests in this region. In this context, state and non-state actors were being called to come up with new solutions to achieve those interests. Certainly not in all cases the negotiations were completed or not yet found a generally accepted formula for others to apply, but most of them show off their values. The main environmental threats to security environment in the Black Sea region are represented by ethnic conflicts and territorial secessionism. A significant contribution to the security environment of the Black Sea region has the phenomenon of globalization, which in this region is manifested by a steady increase in traffic and volume of shipping passage of communication, which largely affects the security in the region. Globalization and the need for energy resources in the Black Sea was an important area not only as energy transport route, but as a potential supplier of material energy (oil and natural gas. Black Sea Basin can be stabilized and secured only by the will and input from all States and interested international organizations in pragmatic and effective institutional frameworks, meant to promote and protect the common interests of countries decided to participate in actions aimed at ensuring a stable environment security.

  11. Black hole quantum mechanics in the presence of species

    International Nuclear Information System (INIS)

    Dvali, G.; Gomez, C.; Luest, D.


    Recently within the context of a microscopic quantum theory, the Black Hole's Quantum N-Portrait, it was shown that continuous global symmetries are compatible with quantum black hole physics. In the present paper we revise within the same framework the semi-classical black hole bound on the number of particle species N species . We show that unlike the bound on global charge, the bound on species survives in the quantum picture and gives rise to a new fundamental length-scale, L species = √(N species ) L P , beyond which the resolution of species identities is impossible. This finding nullifies the so-called species problem. This scale sets the size of the lightest quantum black hole in the theory, Planckion. A crucial difference between the gravitational and non-gravitational species emerges. For gravitational species, the lightest black holes are exactly at the scale of perturbative unitarity violation, which is a strong indication for self-UV-completion of gravity. However, non-gravitational species create a gap between the perturbative unitarity scale and the lightest black holes, which must be filled by some unitarity-restoring physics. Thus, self-UV-completion of gravity implies that the number of non-gravitational species must not exceed the gravitational ones. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. The Adaptation Gap Report - a Preliminary Assessment

    DEFF Research Database (Denmark)

    Alverson, Keith; Olhoff, Anne; Noble, Ian

    This first Adaptation Gap report provides an equally sobering assessment of the gap between adaptation needs and reality, based on preliminary thinking on how baselines, future goals or targets, and gaps between them might be defined for climate change adaptation. The report focuses on gaps in de...

  13. Gap junctions and motor behavior

    DEFF Research Database (Denmark)

    Kiehn, Ole; Tresch, Matthew C.


    The production of any motor behavior requires coordinated activity in motor neurons and premotor networks. In vertebrates, this coordination is often assumed to take place through chemical synapses. Here we review recent data suggesting that electrical gap-junction coupling plays an important role...... to the production of motor behavior in adult mammals....

  14. Globalization and the Gender Gap

    NARCIS (Netherlands)

    Oostendorp, R.H.


    There are several theoretical reasons why globalization will have a narrowing as well as a widening effect on the gender wage gap, but little is known about the actual impact, except for some country studies. This study contributes to the literature in three respects. First, it is a large

  15. Project LOCAL - Bridging The Gap (United States)

    Haven, Robert N.


    Project LOCAL, a not-for-profit regional consortium, offers a broad spectrum of in-service training courses tailored to meet the needs of educators in various disciplines and levels of experience. The purpose of these offerings is to bridge the communication gap between innovative centers in computer-oriented education and staff members in Boston…

  16. Talent Management: Bridging the Gap (United States)


    culling continues at each grade. By this process, the model proposes to raise the talent distribution and level. Professional sports use this method... TALENT MANAGEMENT: BRIDGING THE GAP A thesis presented to the Faculty of the U.S. Army Command and General Staff College in...

  17. Skill gap analysis and training needs in Indian aerospace industry

    Directory of Open Access Journals (Sweden)

    Premkumar Balaraman


    Full Text Available Purpose: The main objective of the paper is on assessing the global aerospace industry as well as Indian scenario, and attempts to assess the skill gaps and training needs of Indian aerospace industry.  Design/methodology/approach: The study is qualitative in nature, and employs wide array of qualitative tools which includes desktop study, focus group interviews and secondary sources of information. Around 10 focus groups were used in the study, with each focus group having a minimum of 6 members of experts in the aerospace and allied industries. The study evolved into a 2 staged one, with the first study elucidating the growing importance and potential of aerospace industry, justifying the significance to take forward the second part of the study. And the second study specifically focuses on skill gaps and training needs. Findings and Originality/value: The Study yields varied results on existing generic expectations of aerospace industry, specific needs of aerospace industry, identification of aerospace job categories unique to aerospace industry, key issues of training in Indian scenario and recommendations. The paper in summary reflects the current scenario of aerospace industry potentials for India and its likely impact on skills gap and training needs. Practical implications: Skills gap is a significant gap between an organization’s current capabilities and the skills it needs to achieve its goals. As a number of Global forecasts project, India as an emerging aviation market, the skill gaps in this sector is predicted to be huge and necessitates the study on assessing the skill gaps and its allied training needs. Originality/value: The Study is highly original and first one of its kind in reflecting the current situation of the skills gap and training needs in Indian Aerospace industry. The focus group interviews were conducted with the experts at various levels in the industyr without any bias yielding valid and realtime data for the

  18. Achieving Public Schools (United States)

    Abowitz, Kathleen Knight


    Public schools are functionally provided through structural arrangements such as government funding, but public schools are achieved in substance, in part, through local governance. In this essay, Kathleen Knight Abowitz explains the bifocal nature of achieving public schools; that is, that schools are both subject to the unitary Public compact of…

  19. Merging Black Holes (United States)

    Centrella, Joan


    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. Pulsation of black holes (United States)

    Gao, Changjun; Lu, Youjun; Shen, You-Gen; Faraoni, Valerio


    The Hawking-Penrose singularity theorem states that a singularity forms inside a black hole in general relativity. To remove this singularity one must resort to a more fundamental theory. Using a corrected dynamical equation arising in loop quantum cosmology and braneworld models, we study the gravitational collapse of a perfect fluid sphere with a rather general equation of state. In the frame of an observer comoving with this fluid, the sphere pulsates between a maximum and a minimum size, avoiding the singularity. The exterior geometry is also constructed. There are usually an outer and an inner apparent horizon, resembling the Reissner-Nordström situation. For a distant observer the horizon crossing occurs in an infinite time and the pulsations of the black hole quantum "beating heart" are completely unobservable. However, it may be observable if the black hole is not spherical symmetric and radiates gravitational wave due to the quadrupole moment, if any.

  1. Turbulent black holes. (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis


    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.

  2. Bringing Black Holes Home (United States)

    Furmann, John M.


    Black holes are difficult to study because they emit no light. To overcome this obstacle, scientists are trying to recreate a black hole in the laboratory. The article gives an overview of the theories of Einstein and Hawking as they pertain to the construction of the Large Hadron Collider (LHC) near Geneva, Switzerland, scheduled for completion in 2006. The LHC will create two beams of protons traveling in opposing directions that will collide and create a plethora of scattered elementary particles. Protons traveling in opposite directions at very high velocities may create particles that come close enough to each other to feel their compacted higher dimensions and create a mega force of gravity that can create tiny laboratory-sized black holes for fractions of a second. The experiments carried out with LHC will be used to test modern string theory and relativity.

  3. Coiffured black rings (United States)

    Bena, Iosif; Ross, Simon F.; Warner, Nicholas P.


    We describe a new type of hair on supersymmetric black string and black ring solutions, which produces the largest known violation of black hole uniqueness, parameterized by an arbitrary function and hence an infinite number of continuous parameters. The new solutions can have non-trivial density profiles for the electric fields along the horizon, and yet have a geometry that is regular, although generically not infinitely differentiable, at the horizon. Both neutral and charged probes can cross the horizon without experiencing divergent forces. We also find restricted examples, parameterized by a few arbitrary continuous parameters, where the charge densities fluctuate but the metric does not and hence is completely differentiable. Our new class of solutions owes its existence to a mechanism reminiscent of the Q-ball: in the simplest examples the metric has more symmetry than the matter that supports it.

  4. Black hole gravitohydromagnetics

    CERN Document Server

    Punsly, Brian


    Black hole gravitohydromagnetics (GHM) is developed from the rudiments to the frontiers of research in this book. GHM describes plasma interactions that combine the effects of gravity and a strong magnetic field, in the vicinity (ergosphere) of a rapidly rotating black hole. This topic was created in response to the astrophysical quest to understand the central engines of radio loud extragalactic radio sources. The theory describes a "torsional tug of war" between rotating ergospheric plasma and the distant asymptotic plasma that extracts the rotational inertia of the black hole. The recoil from the struggle between electromagnetic and gravitational forces near the event horizon is manifested as a powerful pair of magnetized particle beams (jets) that are ejected at nearly the speed of light. These bipolar jets feed large-scale magnetized plasmoids on scales as large as millions of light years (the radio lobes of extragalactic radio sources). This interaction can initiate jets that transport energy fluxes exc...

  5. Slowly balding black holes

    International Nuclear Information System (INIS)

    Lyutikov, Maxim; McKinney, Jonathan C.


    The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes N B =eΦ ∞ /(πc(ℎ/2π)), where Φ ∞ ≅2π 2 B NS R NS 3 /(P NS c) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  6. Black widow spider envenomation. (United States)

    Peterson, Michael E


    Black widow spiders are found throughout the continental United States and north into the southern Canadian provinces. Male black widow spiders are of little medical importance. Female black widow spiders can be 20 times larger than males. The female can be identified by the hourglass pattern, red or orange in color, on the ventral aspect of her shiny, globose black abdomen. Black widow spiders control the amount of venom they inject; an estimated 15% of bites to humans are non-envenomating. Cats are very sensitive to the venom and deaths are common. Dogs have severe clinical signs but are considered more resistant than cats. A single bite is capable of delivering a lethal dose of venom to companion animals. There are several toxic components consisting of five or six biologically active proteins. These include a potent mammalian neurotoxin called alpha-latrotoxin, which induces neurotransmitter release from nerve terminals. Acetylcholine, noradrenalin, dopamine, glutamate, and enkephalin systems are all susceptible to the toxin. Onset of clinical signs usually occurs during the first 8 hours post envenomation. The condition is extremely painful in moderate to severe envenomations. Abdominal rigidity without tenderness is a hallmark sign of Latrodectus envenomation. In cats, paralytic signs may occur early and are particularly marked. Hypertension is a significant threat. First aid is of no value in the treatment. The primary treatment for black widow spider envenomation is the administration of specific antivenin, which provides the most permanent and quickest relief of the envenomation syndrome, usually within 30 minutes of infusion. The prognosis of Latrodectus envenomation is uncertain of several days, and complete recovery may take weeks.

  7. Achieving Energy Efficient Ship Operations Under Third Party Management

    DEFF Research Database (Denmark)

    Taudal Poulsen, René; Sornn-Friese, Henrik


    of time to produce and provide reliable energy efficiency information cause energy efficiency gaps. The paper brings together the energy efficiency and ship management literatures, demonstrating how ship management models influence energy efficiency in ship operations. Achieving energy efficiency in ship...... operations is particularly challenging under third party ship management. Finally, the paper discusses management implications for shipping companies, which outsource ship management to third parties.......Profitable energy saving measures are often not fully implemented in shipping, causing energy efficiency gaps. The paper identifies energy efficiency gaps in ship operations, and explores their causes. Lack of information on energy efficiency, lack of energy training at sea and onshore and lack...

  8. Characterizing Black Hole Mergers (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard


    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  9. Superfluid Black Holes. (United States)

    Hennigar, Robie A; Mann, Robert B; Tjoa, Erickson


    We present what we believe is the first example of a "λ-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid ^{4}He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically anti-de Sitter hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  10. Are black holes springlike? (United States)

    Good, Michael R. R.; Ong, Yen Chin


    A (3 +1 )-dimensional asymptotically flat Kerr black hole angular speed Ω+ can be used to define an effective spring constant, k =m Ω+2. Its maximum value is the Schwarzschild surface gravity, k =κ , which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: 2 π T =κ -k . Hooke's law, in the extremal limit, provides the force F =1 /4 , which is consistent with the conjecture of maximum force in general relativity.

  11. Bulletproof Black Man

    DEFF Research Database (Denmark)

    Højer, Henrik


    Netflix’ kommende serie om den sorte Marvel-helt Luke Cage lander snart – midt i de aktuelle racekonflikter i USA. I GIF-anatomien "Bulletproof Black Man" sætter Henrik Højer serien ind i dens amerikanske kontekst.......Netflix’ kommende serie om den sorte Marvel-helt Luke Cage lander snart – midt i de aktuelle racekonflikter i USA. I GIF-anatomien "Bulletproof Black Man" sætter Henrik Højer serien ind i dens amerikanske kontekst....

  12. Virtual Black Holes


    Hawking, Stephen W.


    One would expect spacetime to have a foam-like structure on the Planck scale with a very high topology. If spacetime is simply connected (which is assumed in this paper), the non-trivial homology occurs in dimension two, and spacetime can be regarded as being essentially the topological sum of $S^2\\times S^2$ and $K3$ bubbles. Comparison with the instantons for pair creation of black holes shows that the $S^2\\times S^2$ bubbles can be interpreted as closed loops of virtual black holes. It is ...

  13. Better Physician's 'Black Bags' (United States)


    The "black bag" is outgrowth of astronaut monitoring technology from NASA's Johnson Space Center. Technically known as the portable medical status system, a highly advanced physician's "black bag" weighs less than 30 pounds, yet contains equipment for monitoring and recording vital signs, electrocardiograms, and electroencephalograms. Liquid crystal displays are used to present 15 digits of data simultaneously for long periods of time without excessive use of battery power. Single printed circuit card contains all circuitry required to measure and display vital signs such as heart and respiration rate, temperature, and blood pressure.

  14. Partons and black holes

    International Nuclear Information System (INIS)

    Susskind, L.; Griffin, P.


    A light-front renormalization group analysis is applied to study matter which falls into massive black holes, and the related problem of matter with transplankian energies. One finds that the rate of matter spreading over the black hole's horizon unexpectedly saturates the causality bound. This is related to the transverse growth behavior of transplankian particles as their longitudinal momentum increases. This growth behavior suggests a natural mechanism to implement 't Hooft's scenario that the universe is an image of data stored on a 2 + 1 dimensional hologram-like projection

  15. Lesbian identities in South Africa : Black and White experiences in Johannesburg



    M.A. This dissertation attempts to understand the different meanings attached to lesbian identities by comparing the experiences of black and white lesbian women living in South Africa. Literature of the experiences of black lesbian women, especially in South Africa, is plentiful. Thus, by including white lesbian women in the sample, this dissertation begins to fill a gap in literature and provide some insights into an overall experience of lesbian identity in South Africa. In-depth interv...

  16. Minding and mending the gap: Social psychological interventions to reduce educational disparities. (United States)

    Spitzer, Brian; Aronson, Joshua


    Achievement gaps continue to garner a great deal of attention both in academic and in popular circles. Many students continue to struggle despite broad educational reforms aimed at narrowing these gaps in learning and performance. In this article, we review a number of social psychological interventions that show promise in reducing gaps in achievement, not by addressing structural barriers to achievement, but by helping students cope with threats to their identity that impair intellectual functioning and motivation. For example, interventions involving meditation, role models, emotional reappraisal, growth mindsets, imagining possible selves, self-affirmations, belongingness and cooperative learning have been shown to ameliorate threats to identity and raise achievement. We describe and evaluate these social psychological interventions. Many achievement gaps involve a psychological predicament: a threat to one's social identity or to one's sense of belonging. Students' implicit theories - how they mind the gap - can act as barriers to their success. By helping students cope with these threats, these theory-based interventions represent a genuine advance in the way schools may reduce gaps in achievement. These interventions show how students' educational success depends partly on fluid aspects of context - how tasks are framed, who else is in the room, or what they believe about intelligence. Because of this fluidity, these interventions may not work in all settings. Achievement gaps are ultimately caused by a variety of factors, both objective and subjective that produce inequality. The research reviewed here suggests that even without changes in objective barriers to success, brief psychological interventions can narrow what many see as intractable gaps in academic achievement. © 2015 The British Psychological Society.

  17. Quantum confinement in black phosphorus-based nanostructures (United States)

    Cupo, Andrew; Meunier, Vincent


    The modification of an idealized infinite bulk system by dimensional reduction or structural distortion results in quantum confinement effects (QCEs). For example, dimensional reduction of a black phosphorus structure leads to the realization of few-layer systems, creation of edges and surfaces, nanoribbons, quantum dots, and antidot lattices while structural distortion involves simple bending (including nanotubes) and rippling. Black phosphorus (‘phosphorene’ in the single-layer limit) has been of recent interest due to its relatively large charge carrier mobility and moderate semiconducting band gap, which remains direct irrespective of the number of layers. In this review the state-of-the-art properties of black phosphorus in its dimensionally reduced and structurally distorted forms are discussed, with emphasis on how quantum confinement impacts the material’s properties.

  18. Stacking dependence of carrier transport properties in multilayered black phosphorous. (United States)

    Sengupta, A; Audiffred, M; Heine, T; Niehaus, T A


    We present the effect of different stacking orders on carrier transport properties of multi-layer black phosphorous. We consider three different stacking orders AAA, ABA and ACA, with increasing number of layers (from 2 to 6 layers). We employ a hierarchical approach in density functional theory (DFT), with structural simulations performed with generalized gradient approximation (GGA) and the bandstructure, carrier effective masses and optical properties evaluated with the meta-generalized gradient approximation (MGGA). The carrier transmission in the various black phosphorous sheets was carried out with the non-equilibrium green's function (NEGF) approach. The results show that ACA stacking has the highest electron and hole transmission probabilities. The results show tunability for a wide range of band-gaps, carrier effective masses and transmission with a great promise for lattice engineering (stacking order and layers) in black phosphorous.

  19. Pressure-Induced Electronic Transition in Black Phosphorus (United States)

    Xiang, Z. J.; Ye, G. J.; Shang, C.; Lei, B.; Wang, N. Z.; Yang, K. S.; Liu, D. Y.; Meng, F. B.; Luo, X. G.; Zou, L. J.; Sun, Z.; Zhang, Y.; Chen, X. H.


    In a semimetal, both electrons and holes contribute to the density of states at the Fermi level. The small band overlaps and multiband effects engender novel electronic properties. We show that a moderate hydrostatic pressure effectively suppresses the band gap in the elemental semiconductor black phosphorus. An electronic topological transition takes place at approximately 1.2 GPa, above which black phosphorus evolves into a semimetal state that is characterized by a colossal positive magnetoresistance and a nonlinear field dependence of Hall resistivity. The Shubnikov-de Haas oscillations detected in magnetic field reveal the complex Fermi surface topology of the semimetallic phase. In particular, we find a nontrivial Berry phase in one Fermi surface that emerges in the semimetal state, as evidence of a Dirac-like dispersion. The observed semimetallic behavior greatly enriches the material property of black phosphorus and sets the stage for the exploration of novel electronic states in this material.

  20. Black Elite: The New Market for Highly Educated Black Americans. (United States)

    Freeman, Richard B.

    This examination of the collapse in traditional discriminatory patterns in the market for highly qualified black Americans documents the World War II gain of college trained and related high level black workers, investigates the response of black college students and qualified personnel to the new market setting, and explores the factors that…

  1. Black holes in loop quantum gravity. (United States)

    Perez, Alejandro


    This is a review of results on black hole physics in the context of loop quantum gravity. The key feature underlying these results is the discreteness of geometric quantities at the Planck scale predicted by this approach to quantum gravity. Quantum discreteness follows directly from the canonical quantization prescription when applied to the action of general relativity that is suitable for the coupling of gravity with gauge fields, and especially with fermions. Planckian discreteness and causal considerations provide the basic structure for the understanding of the thermal properties of black holes close to equilibrium. Discreteness also provides a fresh new look at more (at the moment) speculative issues, such as those concerning the fate of information in black hole evaporation. The hypothesis of discreteness leads, also, to interesting phenomenology with possible observational consequences. The theory of loop quantum gravity is a developing program; this review reports its achievements and open questions in a pedagogical manner, with an emphasis on quantum aspects of black hole physics.

  2. Higher spin black holes with soft hair

    Energy Technology Data Exchange (ETDEWEB)

    Grumiller, Daniel [Institute for Theoretical Physics, TU Wien,Wiedner Hauptstrasse 8-10/136, Vienna, A-1040 (Austria); Pérez, Alfredo [Centro de Estudios Científicos (CECs),Av. Arturo Prat 514, Valdivia (Chile); Prohazka, Stefan [Institute for Theoretical Physics, TU Wien,Wiedner Hauptstrasse 8-10/136, Vienna, A-1040 (Austria); Tempo, David; Troncoso, Ricardo [Centro de Estudios Científicos (CECs),Av. Arturo Prat 514, Valdivia (Chile)


    We construct a new set of boundary conditions for higher spin gravity, inspired by a recent “soft Heisenberg hair”-proposal for General Relativity on three-dimensional Anti-de Sitter space. The asymptotic symmetry algebra consists of a set of affine û(1) current algebras. Its associated canonical charges generate higher spin soft hair. We focus first on the spin-3 case and then extend some of our main results to spin-N, many of which resemble the spin-2 results: the generators of the asymptotic W{sub 3} algebra naturally emerge from composite operators of the û(1) charges through a twisted Sugawara construction; our boundary conditions ensure regularity of the Euclidean solutions space independently of the values of the charges; solutions, which we call “higher spin black flowers”, are stationary but not necessarily spherically symmetric. Finally, we derive the entropy of higher spin black flowers, and find that for the branch that is continuously connected to the BTZ black hole, it depends only on the affine purely gravitational zero modes. Using our map to W-algebra currents we recover well-known expressions for higher spin entropy. We also address higher spin black flowers in the metric formalism and achieve full consistency with previous results.

  3. Soft X-ray transients in the Hertzsprung gap (United States)

    Kolb, Ulrich


    We apply the disc instability model for soft X-ray transients to identify system parameters along evolutionary sequences of black hole X-ray binaries (BHXBs) that are consistent with transient behaviour. In particular, we focus on the hitherto neglected group of BHXBs with intermediate-mass giant donor stars. These spend a significant fraction of their X-ray active phase crossing the Hertzsprung gap. Three case B binary sequences with a black hole accretor and 2.5-Msolar initial donor mass are presented in detail. We formulate rules which summarize the behaviour of these sequences and provide an approximate description for case B mass-transfer in intermediate-mass BHXBs. Chiefly, the time-scale of the overall radius expansion is given by the initial donor mass, while the surface appearance is determined by the current donor mass. With these rules we obtain a general overview of transient and persistent behaviour of all intermediate-mass BHXBs by just considering single star sequences of different mass. We find that although systems in the process of crossing the Hertzsprung gap are in general persistently bright, with Eddington or super-Eddington transfer rates, there is a narrow instability strip where transient behaviour is possible. This strip extends over a secondary mass range 2.0<~M_2<~3.5 Msolar. GRO J1655-40 might be such a system. We predict that there are no BHXB transients with (sub)giant donors more massive than 3.5 Msolar, and no neutron star transients in the Hertzsprung gap.

  4. Achieving excellence in training

    International Nuclear Information System (INIS)

    Mangin, A.M.; Solymossy, J.M.


    Operating a nuclear power plant is a uniquely challenging activity, requiring a high degree of competence from all who are involved. Achieving and maintaining this competence requires excellence in training. But what does excellence mean, and how do we achieve it. Based on the experience gained by INPO in plant training evaluations and accreditation activities, this paper describes some of the actions that can be taken to achieve the quality appropriate for nuclear power plant training. These actions are discussed in relation to the four phases of a performance-based training system: (1) needs analysis, (2) program design and development, (3) implementation, and (4) evaluation and improvement

  5. [Achievement of therapeutic objectives]. (United States)

    Mantilla, Teresa


    Therapeutic objectives for patients with atherogenic dyslipidemia are achieved by improving patient compliance and adherence. Clinical practice guidelines address the importance of treatment compliance for achieving objectives. The combination of a fixed dose of pravastatin and fenofibrate increases the adherence by simplifying the drug regimen and reducing the number of daily doses. The good tolerance, the cost of the combination and the possibility of adjusting the administration to the patient's lifestyle helps achieve the objectives for these patients with high cardiovascular risk. Copyright © 2014 Sociedad Española de Arteriosclerosis y Elsevier España, S.L. All rights reserved.

  6. Black strings ending on horizons (United States)

    Haddad, Nidal


    We construct an approximate static gravitational solution of the Einstein equations, with negative cosmological constant, describing a test black string stretching from the boundary of the Schwarzschild-AdS5 black brane toward the horizon. The construction builds on a derivative expansion method, assuming that the black brane metric changes slowly along the black string direction. We provide a solution up to second order in derivatives, and it implies, in particular, that the black string must shrink to zero size at the horizon of the black brane. In the near-horizon region of the black brane, where the two horizons intersect, we provide an exact solution of a cone that describes two intersecting horizons at different temperatures. Moreover, we show that this solution equally describes a thin and long black droplet.

  7. Reflections on a Black Mirror


    Good, Michael R. R.


    A black mirror is an accelerated boundary that produces particles in an exact correspondence to an evaporating black hole. We investigate the spectral dynamics of the particle creation during the formation process.

  8. Quantum aspects of black holes

    CERN Document Server


    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.

  9. Black Sea Bass genetic connectivity (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Microsatellite analysis of black sea bass was undertaken to determine magnitude and direction of mixing of black seabass across the Hatteras boundary, as well as...

  10. Meer bekend over Black Mold

    NARCIS (Netherlands)

    Duyvesteijn, R.G.E.; Kohrman, E.


    In de vollegrondsrozenteelt zorgde Black Mold in 2007 voor een groot aantal mislukte oculaties. In 2008 waren er aanzienlijk minder problemen. Uit onderzoek is meer bekend over de oorzaak en bestrijding van Black Mold.

  11. Aspects of hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Anabalón, Andrés, E-mail: [Departamento de Ciencias, Facultad de Artes Liberales y Facultad de Ingeniería y Ciencias, Universidad Adolfo Ibáñez, Viña del Mar (Chile); Astefanesei, Dumitru [Instituto de Física, Pontificia Universidad Católica de Valparaíso, Casilla 4059, Valparaíso (Chile)


    We review the existence of exact hairy black holes in asymptotically flat, anti-de Sitter and de Sitter space-times. We briefly discuss the issue of stability and the charging of the black holes with a Maxwell field.

  12. Decreased extension gap and valgus alignment after implantation of total knee prosthesis in primary varus knees. (United States)

    Minoda, Yukihide; Nakagawa, Shigeru; Sugama, Ryo; Ikawa, Tessyu; Noguchi, Takahiro; Hirakawa, Masashi; Matsui, Yoshio; Nakamura, Hiroaki


    It was hypothesised that implantation of a total knee prosthesis may change the size and shape of the joint gap. To test this hypothesis, a tensor device was used which was specifically designed to reproduce the conditions before and after implantation, including attachment of the polyethylene insert trial. This study aimed to compare the joint gaps before and after implantation of a total knee prosthesis using this new tensor device. A total of 259 primary varus knees were included in this study. Knees were exposed using a medial parapatellar approach, and the anterior and posterior cruciate ligaments were resected. After the trial reduction, the intraoperative joint gap kinematics was measured using the tensor device. Implantation of a total knee prosthesis decreased the size of the extension joint gap and made it valgus, but did not influence the size or shape of the flexion joint gap. The present findings suggest that the classical gap technique, which creates equal and rectangular extension and flexion joint gaps in the bone cutting surface, results in an imbalance between the extension and flexion joint gaps after implantation. To achieve equal and rectangular extension and flexion joint gaps after implantation, the prepared extension joint gap should be about 2 mm larger than the flexion joint gap and slightly varus before implantation in primary varus knees. Therapeutic study, Level II.

  13. Convergent use of RhoGAP toxins by eukaryotic parasites and bacterial pathogens.

    Directory of Open Access Journals (Sweden)

    Dominique Colinet


    Full Text Available Inactivation of host Rho GTPases is a widespread strategy employed by bacterial pathogens to manipulate mammalian cellular functions and avoid immune defenses. Some bacterial toxins mimic eukaryotic Rho GTPase-activating proteins (GAPs to inactivate mammalian GTPases, probably as a result of evolutionary convergence. An intriguing question remains whether eukaryotic pathogens or parasites may use endogenous GAPs as immune-suppressive toxins to target the same key genes as bacterial pathogens. Interestingly, a RhoGAP domain-containing protein, LbGAP, was recently characterized from the parasitoid wasp Leptopilina boulardi, and shown to protect parasitoid eggs from the immune response of Drosophila host larvae. We demonstrate here that LbGAP has structural characteristics of eukaryotic RhoGAPs but that it acts similarly to bacterial RhoGAP toxins in mammals. First, we show by immunocytochemistry that LbGAP enters Drosophila immune cells, plasmatocytes and lamellocytes, and that morphological changes in lamellocytes are correlated with the quantity of LbGAP they contain. Demonstration that LbGAP displays a GAP activity and specifically interacts with the active, GTP-bound form of the two Drosophila Rho GTPases Rac1 and Rac2, both required for successful encapsulation of Leptopilina eggs, was then achieved using biochemical tests, yeast two-hybrid analysis, and GST pull-down assays. In addition, we show that the overall structure of LbGAP is similar to that of eukaryotic RhoGAP domains, and we identify distinct residues involved in its interaction with Rac GTPases. Altogether, these results show that eukaryotic parasites can use endogenous RhoGAPs as virulence factors and that despite their differences in sequence and structure, eukaryotic and bacterial RhoGAP toxins are similarly used to target the same immune pathways in insects and mammals.

  14. Global Gaps in Clean Energy RD and D

    Energy Technology Data Exchange (ETDEWEB)



    This report seeks to inform decision makers seeking to prioritise RD&D investments in a time of financial uncertainty. It is an update of the December 2009 IEA report Global Gaps in Clean Energy Research, Development and Demonstration, which examined whether rates of LCET investment were sufficient to achieve shared global energy and environmental goals (IEA,2009). It discusses the impact of the green stimulus spending announcements, and provides private sector perspectives on priorities for government RD&D spending. Finally, it includes a revised assessment of the gaps in public RD&D, together with suggestions for possible areas for expanded international collaboration on specific LCETs. The conclusion re-affirms the first Global Gaps study finding that governments and industry need to dramatically increase their spending on RD&D for LCETs.

  15. Black Holes in Higher Dimensions

    Directory of Open Access Journals (Sweden)

    Reall Harvey S.


    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.

  16. Využití GAP modelu kvality služeb ve FITcentru Chrudim


    Pecinová, Markéta


    Title: Using the GAP Model of Service Quality in the FITcentrum Chrudim. Objectives: The aim of this thesis is to analyze through GAP model the causes of the gaps that exist between the various levels of interaction in the process of providing services in the FITcentrum Chrudim. Based on the results was assessed the state of the organization and the solution was designed to achieve a higher quality of service and higher customer satisfaction. Methods: For the research is used GAP model of ser...

  17. Newborn Black Holes (United States)

    Science Teacher, 2005


    Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence. The holes are consuming material falling into them while somehow propelling other material away at great speeds. "First comes a blast of gamma rays followed by intense pulses of x-rays. The energies involved are much…

  18. When Black Holes Collide (United States)

    Baker, John


    Among the fascinating phenomena predicted by General Relativity, Einstein's theory of gravity, black holes and gravitational waves, are particularly important in astronomy. Though once viewed as a mathematical oddity, black holes are now recognized as the central engines of many of astronomy's most energetic cataclysms. Gravitational waves, though weakly interacting with ordinary matter, may be observed with new gravitational wave telescopes, opening a new window to the universe. These observations promise a direct view of the strong gravitational dynamics involving dense, often dark objects, such as black holes. The most powerful of these events may be merger of two colliding black holes. Though dark, these mergers may briefly release more energy that all the stars in the visible universe, in gravitational waves. General relativity makes precise predictions for the gravitational-wave signatures of these events, predictions which we can now calculate with the aid of supercomputer simulations. These results provide a foundation for interpreting expect observations in the emerging field of gravitational wave astronomy.

  19. Scholarly Black Market. (United States)

    Sorooshian, Shahryar


    Fake and unethical publishers' activities are known by most of the readers of Science and Engineering Ethics. This letter tries to draw the readers' attention to the hidden side of some of these publishers' business. Here the black market of scholarly articles, which negatively affects the validity and reliability of research in higher education, as well as science and engineering, will be introduced.

  20. Twistors and Black Holes

    NARCIS (Netherlands)

    Neitzke, A.; Pioline, B.; Vandoren, S.


    Motivated by black hole physics in N = 2,D = 4 supergravity, we study the geometry of quaternionic-K¨ahler manifolds Mobtained by the c-map construction from projective special Kähler manifolds Ms. Improving on earlier treatments, we compute the Käahler potentials on the twistor space Z and Swann

  1. on black ironbark (Eucalyptus

    African Journals Online (AJOL)

    (Eucalyptus sideroxylon). B. Buys. Plant Protection Research Institute, Private Bag X5017,. Stellenbosch, 7600 Republic of South Africa. Received May /984; accepted 28 November /986. Black ironbark trees secrete nectar during the night. Argentine ants collected 42% of the nectar before honeybees started foraging in the ...

  2. Trichomicosis pubis: black variety.


    Neri, I; Frassetto, A; Pasquinelli, G; Patrizi, A


    A case of a 25 year old man with the black variety of trichomicosis pubis is presented on account of its extreme rareity. Scanning electron microscopy confirms that trichomicosis pubis is caused by bacterial colonisation of the pubic hair and shows that bacteria are able to penetrate cuticular horny cells directly through their free plasma membrane.

  3. Suburban Black Lives Matter (United States)

    Lewis-McCoy, R. L'Heureux


    This article explores the range of experiences and meanings of Black life in suburban space. Drawing from educational, historical, and sociological literatures, I argue that an underconsideration of suburban space has left many portraits of educational inequality incomplete. The article outlines the emergence of American suburbs and the formation…

  4. Black Psychology. Third Edition. (United States)

    Jones, Reginald L., Ed.

    This book is the third edition of a resource for advanced students and professionals in black psychology in the form of 41 papers organized under 5 subheadings. The "overview" section includes one classic article and offers a new, world view paper. A "perspectives" section treats Afrocentric, humanistic, historical,…

  5. [Reinvesting in Black Communities]. (United States)

    Shipp, James

    Some of the issues involved in promoting home ownership among blacks and investment in inner city communities are discussed in this paper. The experiences of the Bedford Stuyvesant Restoration Corporation in revitalizing Bedford Stuyvesant are described. Economic barriers to prospective home ownership are identified and strategies and programs…

  6. Black Holes and Entanglement

    International Nuclear Information System (INIS)

    Borsten, L.


    An unexpected interplay between the seemingly disparate fields of M-theory and Quantum Information has recently come to light. We summarise these developments, culminating in a classification of 4-qubit entanglement from the physics of STU black holes. Based on work done in collaboration with D. Dahanayake, M. J. Duff, H. Ebrahim, A. Marrani and W. Rubens.

  7. Black Holes and Entanglement (United States)

    Borsten, L.


    An unexpected interplay between the seemingly disparate fields of M-theory and Quantum Information has recently come to light. We summarise these developments, culminating in a classification of 4-qubit entanglement from the physics of STU black holes. Based on work done in collaboration with D. Dahanayake, M. J. Duff, H. Ebrahim, A. Marrani and W. Rubens.

  8. Gaps in EU Foreign Policy

    DEFF Research Database (Denmark)

    Larsen, Henrik

    of Capability-Expectations Gap in the study of European foreign policy. Through examples from relevant literature, Larsen not only demonstrates how this concept sets up standards for the EU as a foreign policy actor (that are not met by most other international actors) but also shows how this curtails analysis......This book argues that theories of European foreign policy are performative: they create the objects they analyse. In this text, Larsen outlines the performativity approach to the role of theories based on the work of Derrida and goes on to examine the performative role of Christopher Hill's concept...... of EU foreign policy. The author goes on to discuss how the widespread use of the concept of ‘gap' affects the way in which EU foreign policy has been studied; and that it always produces the same result: the EU is an unfulfilled actor outside the realm of “normal” actors in IR. This volume offers new...

  9. Watchable Wildlife: The Black Bear (United States)

    Lynn L. Rogers


    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...

  10. Health Issues Facing Black Women. (United States)

    Reid, Inez Smith

    Black women in the United States experience a high incidence of serious health problems and, as a group, receive insufficient and inadequate medical care. The death rate for black women suffering from breast cancer has increased substantially since 1950. Also of great concern is the high incidence of cervical cancer in low income black women…

  11. Uncovering Black Womanhood in Engineering (United States)

    Gibson, Sheree L.; Espino, Michelle M.


    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…

  12. Warped products and black holes

    International Nuclear Information System (INIS)

    Hong, Soon-Tae


    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

  13. Reading Black Literature With Understanding. (United States)

    Alexander, Jean A.

    This paper is a broad study of the field of black American Literature which outlines the important movements, stereotypes, and trends that have had significant influence upon the literature. The changing stereotypes and archetypes of blacks depicted in American literature from the early concept of blacks as "chattels" to the contemporary concept…

  14. Queering Black Racial Identity Development (United States)

    Johnson, Alandis A.; Quaye, Stephen John


    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. Black silicon with black bus-bar strings

    DEFF Research Database (Denmark)

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


    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...

  16. Homolumo Gap and Matrix Model

    CERN Document Server

    Andric, I; Jurman, D; Nielsen, H B


    We discuss a dynamical matrix model by which probability distribution is associated with Gaussian ensembles from random matrix theory. We interpret the matrix M as a Hamiltonian representing interaction of a bosonic system with a single fermion. We show that a system of second-quantized fermions influences the ground state of the whole system by producing a gap between the highest occupied eigenvalue and the lowest unoccupied eigenvalue.

  17. Filling in biodiversity threat gaps

    DEFF Research Database (Denmark)

    Joppa, L. N.; O'Connor, Brian; Visconti, Piero


    increase to 10,000 times the background rate should species threatened with extinction succumb to pressures they face (4). Reversing these trends is a focus of the Convention on Biological Diversity's 2020 Strategic Plan for Biodiversity and its 20 Aichi Targets and is explicitly incorporated...... into the United Nations' 2030 Agenda for Sustainable Development and its 17 Sustainable Development Goals (SDGs). We identify major gaps in data available for assessing global biodiversity threats and suggest mechanisms for closing them....

  18. BOOK REVIEW: Introduction to Black Hole Physics Introduction to Black Hole Physics (United States)

    Tanaka, Takahiro


    expected in the near future. Such hot topics are presented in Section 10: 'Black Holes and All That Jazz'. I would also consider the historical overview of the research on black holes given in Section 1 to be very interesting. Overall, I strongly recognised the intention of the authors not to go into too much detail; in this sense, I would say that the book has the aspect of a showcase of the frontiers of black hole physics. There are many topics which are very interesting but mathematically a little complicated; however, those subjects are appropriately treated so that the reader will not be overloaded with mathematical complexity. For example, in the discussion of black hole perturbation, only scalar field perturbation is discussed. The authors might have discussed gravitational wave perturbation, but this is much more complicated and the essential physics is mostly included in the simplest example of the scalar field. If I were one of the authors, I would consider adding more detailed explanations about several such advanced topics. However, the authors well know that such a challenge just presents a barrier to young students who are going to read this book, and really it is only an introduction to this interesting research field. This style might be the result of the long experience from the lectures over 30 years: the explanations of the subjects that the authors describe in detail are very carefully presented, avoiding logical gaps. In the preface, the authors state that they tried hard to answer students' questions as much as possible; I think that the authors' method in this respect is very successful.

  19. Prometheus and the Keeler gap (United States)

    Tajeddine, Radwan; Nicholson, Phillip D.; Hedman, Matthew M.; French, Richard G.; Tiscareno, Matthew S.; Burns, Joseph A.


    Linblad resonances with Saturn’s satellites are located at many radii in the rings. While some cause density or bending waves, others hold gap edges from spreading, like the 2:1 resonance with Mimas located at the B-ring edge, the 7:6 resonance with Janus at the A-ring edge, and the 32:31 resonance with Prometheus at the inner edge of the Keeler gap. The latter is the case of study here.Theoretically, the inner edge of the Keeler gap should have 32 regular sinusoidal lobes, where either the maximum or the minimum radius is expected to be aligned with Prometheus and rotating with its mean motion. We show that such is not the case. Fit of occultation data shows the presence of the 32:31 resonance, however, the fit residuals is as high as the amplitude of the resonance amplitude (about 2 km). Analysis of the ISS data, shows irregularities overlapping the lobes (Tiscareno et al. 2005, DPS), that follow Keplerian motion. These irregularities may be due to clumps of particles with different eccentricities than the rest of the edge particles. This phenomenon may be caused by the resonance, as it has not been observed at other circular edges were no resonance is present at their location. The ISS data also shows that the lobe’s minimum/maximum is not perfectly aligned with the longitude of Prometheus, which may be due to libration about the centre of the resonance.

  20. Gap Junctions and Chagas Disease (United States)

    Adesse, Daniel; Goldenberg, Regina Coeli; Fortes, Fabio S.; Jasmin; Iacobas, Dumitru A.; Iacobas, Sanda; de Carvalho, Antonio Carlos Campos; de Narareth Meirelles, Maria; Huang, Huan; Soares, Milena B.; Tanowitz, Herbert B.; Garzoni, Luciana Ribeiro; Spray, David C.


    Gap junction channels provide intercellular communication between cells. In the heart, these channels coordinate impulse propagation along the conduction system and through the contractile musculature, thereby providing synchronous and optimal cardiac output. As in other arrhythmogenic cardiac diseases, chagasic cardiomyopathy is associated with decreased expression of the gap junction protein connexin43 (Cx43) and its gene. Our studies of cardiac myocytes infected with Trypanosoma cruzi have revealed that synchronous contraction is greatly impaired and gap junction immunoreactivity is lost in infected cells. Such changes are not seen for molecules forming tight junctions, another component of the intercalated disc in cardiac myocytes. Transcriptomic studies of hearts from mouse models of Chagas disease and from acutely infected cardiac myocytes in vitro indicate profound remodelling of gene expression patterns involving heart rhythm determinant genes, suggesting underlying mechanisms of the functional pathology. One curious feature of the altered expression of Cx43 and its gene expression is that it is limited in both extent and location, suggesting that the more global deterioration in cardiac function may result in part from spread of damage signals from more seriously compromised cells to healthier ones. PMID:21884887