Science.gov

Sample records for black hole-bulge relations

  1. Black Hole-Bulge Relation for Narrow-Line Objects

    NASA Astrophysics Data System (ADS)

    Bian, Wei-Hao; Zhao, Yong-Heng

    2003-02-01

    It has been thought that narrow-line Seyfert 1 galaxies are likely to be in the early stages of the evolution of active galaxies. To test this suggestion, the ratios of the central massive black hole (MBH) mass to the bulge mass (Mbh/Mbulge) were estimated for 22 Narrow Line AGNs (NL AGNs). It is found that NL AGNs appear to have genuinely lower MBH/Bulge mass ratio (Mbh/Mbulge). The mean log (Mbh/Mbulge) for 22 NL AGNs is -3.9 ± 0.07, which is an order of magnitude lower than that for Broad Line AGNs and quiescent galaxies. We suggest a nonlinear MBH/Bulge relation and find there exists a relation between the Mbh / Mbulge and the velocity dispersion, σ, derived from the [O III ] width. A scenario of MBH growth for NL AGNs is one of our interpretations of the nonline ar MBH/Bulge relation. The MBH growth timescales for 22 NL AGNs were calculated, with a mean value (1.29 ± 0.24) × 108 yr. Another plausible interpretation is also possible: that NL AGNs occur in low-Mbulge galaxies and that in such galaxies Mbh/Mbulge is lower than that in galaxies with a higher Mbulge, if we consider that NL AGNs already have their ``final'' Mbh/Mbulge. More information of the bulge in NL AGNs is needed to clarify the black hole-bulge relation.

  2. Selection effects in the black hole-bulge relation and its evolution

    NASA Astrophysics Data System (ADS)

    Schulze, A.; Wisotzki, L.

    2011-11-01

    We present an investigation of sample selection effects that influence the observed black hole-bulge relations and its evolution with redshift. We provide a common framework in which all kinds of selection effects on the M•-bulge relations can be investigated, but our main emphasis is on the consequences of using broad-line AGN with virial estimates of black hole masses and their host galaxies to search for evolution in the BH-bulge relation. We identified relevant sources of bias that were not discussed in the literature so far. A particularly important effect is caused by the fact that the active fraction among SMBHs varies considerably with BH mass, in the sense that high-mass BHs are less likely to be active than lower mass ones. In the connection with intrinsic scatter of the BH-bulge relation this effect implies a bias towards a low BH mass at given bulge property. This effect adds to the bias caused by working with luminosity or flux limited samples that were already discussed by others. A quantitative prediction of these biases requires (i) a realistic model of the sample selection function, and (ii) knowledge of relevant underlying distribution functions: the distribution of spheroid properties such as velocity dispersions or masses; the active fraction as a function of BH mass, or alternatively the active black hole mass function; and the Eddington ratio distribution function. We employed our formalism together with recently determined distribution functions to investigate how much existing studies of the M•-bulge relation using AGN hosts might suffer from selection biases. For low-redshift AGN samples we can naturally reproduce the flattening of the relation observed in some studies without having to invoke intrinsic differences in the BH-bulge relation between active and inactive galaxies. When extending our analysis to higher redshift samples we are clearly hampered by limited empirical constraints on the various relevant distribution functions

  3. Precise Black Hole Masses from Megamaser Disks: Black Hole-Bulge Relations at Low Mass

    NASA Astrophysics Data System (ADS)

    Greene, Jenny E.; Peng, Chien Y.; Kim, Minjin; Kuo, Cheng-Yu; Braatz, James A.; Impellizzeri, C. M. V.; Condon, James J.; Lo, K. Y.; Henkel, Christian; Reid, Mark J.

    2010-09-01

    The black hole (BH)-bulge correlations have greatly influenced the last decade of efforts to understand galaxy evolution. Current knowledge of these correlations is limited predominantly to high BH masses (M BHgsim108 M sun) that can be measured using direct stellar, gas, and maser kinematics. These objects, however, do not represent the demographics of more typical L < L* galaxies. This study transcends prior limitations to probe BHs that are an order of magnitude lower in mass, using BH mass measurements derived from the dynamics of H2O megamasers in circumnuclear disks. The masers trace the Keplerian rotation of circumnuclear molecular disks starting at radii of a few tenths of a pc from the central BH. Modeling of the rotation curves, presented by Kuo et al., yields BH masses with exquisite precision. We present stellar velocity dispersion measurements for a sample of nine megamaser disk galaxies based on long-slit observations using the B&C spectrograph on the Dupont telescope and the Dual Imaging Spectrograph on the 3.5 m telescope at Apache Point. We also perform bulge-to-disk decomposition of a subset of five of these galaxies with Sloan Digital Sky Survey imaging. The maser galaxies as a group fall below the M BH-σ* relation defined by elliptical galaxies. We show, now with very precise BH mass measurements, that the low-scatter power-law relation between M BH and σ* seen in elliptical galaxies is not universal. The elliptical galaxy M BH-σ* relation cannot be used to derive the BH mass function at low mass or the zero point for active BH masses. The processes (perhaps BH self-regulation or minor merging) that operate at higher mass have not effectively established an M BH-σ* relation in this low-mass regime.

  4. PRECISE BLACK HOLE MASSES FROM MEGAMASER DISKS: BLACK HOLE-BULGE RELATIONS AT LOW MASS

    SciTech Connect

    Greene, Jenny E.; Peng, Chien Y.; Kim, Minjin; Kuo, Cheng-Yu; Braatz, James A.; Impellizzeri, C. M. Violette; Condon, James J.; Lo, K. Y.; Henkel, Christian; Reid, Mark J.

    2010-09-20

    The black hole (BH)-bulge correlations have greatly influenced the last decade of efforts to understand galaxy evolution. Current knowledge of these correlations is limited predominantly to high BH masses (M{sub BH{approx}}>10{sup 8} M{sub sun}) that can be measured using direct stellar, gas, and maser kinematics. These objects, however, do not represent the demographics of more typical L < L* galaxies. This study transcends prior limitations to probe BHs that are an order of magnitude lower in mass, using BH mass measurements derived from the dynamics of H{sub 2}O megamasers in circumnuclear disks. The masers trace the Keplerian rotation of circumnuclear molecular disks starting at radii of a few tenths of a pc from the central BH. Modeling of the rotation curves, presented by Kuo et al., yields BH masses with exquisite precision. We present stellar velocity dispersion measurements for a sample of nine megamaser disk galaxies based on long-slit observations using the B and C spectrograph on the Dupont telescope and the Dual Imaging Spectrograph on the 3.5 m telescope at Apache Point. We also perform bulge-to-disk decomposition of a subset of five of these galaxies with Sloan Digital Sky Survey imaging. The maser galaxies as a group fall below the M{sub BH}-{sigma}{sub *} relation defined by elliptical galaxies. We show, now with very precise BH mass measurements, that the low-scatter power-law relation between M{sub BH} and {sigma}{sub *} seen in elliptical galaxies is not universal. The elliptical galaxy M{sub BH}-{sigma}{sub *} relation cannot be used to derive the BH mass function at low mass or the zero point for active BH masses. The processes (perhaps BH self-regulation or minor merging) that operate at higher mass have not effectively established an M{sub BH}-{sigma}{sub *} relation in this low-mass regime.

  5. THE (BLACK HOLE)-BULGE MASS SCALING RELATION AT LOW MASSES

    SciTech Connect

    Graham, Alister W.; Scott, Nicholas

    2015-01-01

    Several recent papers have reported on the occurrence of active galactic nuclei (AGNs) containing undermassive black holes relative to a linear scaling relation between black hole mass (M {sub bh}) and host spheroid stellar mass (M {sub sph,} {sub *}). However, dramatic revisions to the M {sub bh}-M {sub sph,} {sub *} and M {sub bh}-L {sub sph} relations, based on samples containing predominantly inactive galaxies, have recently identified a new steeper relation at M {sub bh} ≲ (2-10) × 10{sup 8} M {sub ☉}, roughly corresponding to M {sub sph,} {sub *} ≲ (0.3-1) × 10{sup 11} M {sub ☉}. We show that this steeper, quadratic-like M {sub bh}-M {sub sph,} {sub *} relation defined by the Sérsic galaxies, i.e., galaxies without partially depleted cores, roughly tracks the apparent offset of the AGN having 10{sup 5} ≲ M {sub bh}/M {sub ☉} ≲ 0.5 × 10{sup 8}. That is, these AGNs are not randomly offset with low black hole masses, but also follow a steeper (nonlinear) relation. As noted by Busch et al., confirmation or rejection of a possible AGN offset from the steeper M {sub bh}-M {sub sph,} {sub *} relation defined by the Sérsic galaxies will benefit from improved stellar mass-to-light ratios for the spheroids hosting these AGNs. Several implications for formation theories are noted. Furthermore, reasons for possible under- and overmassive black holes, the potential existence of intermediate mass black holes (<10{sup 5} M {sub ☉}), and the new steep (black hole)-(nuclear star cluster) relation, M{sub bh}∝M{sub nc}{sup 2.7±0.7}, are also discussed.

  6. The Black Hole-Bulge Mass Relation in Megamaser Host Galaxies

    NASA Astrophysics Data System (ADS)

    Läsker, Ronald; Greene, Jenny E.; Seth, Anil; van de Ven, Glenn; Braatz, James A.; Henkel, Christian; Lo, K. Y.

    2016-07-01

    We present Hubble Space Telescope (HST) images for nine megamaser disk galaxies with the primary goal of studying photometric BH-galaxy scaling relations. The megamaser disks provide the highest-precision extragalactic BH mass measurements, while our high-resolution HST imaging affords us the opportunity to decompose the complex nuclei of their late-type hosts in detail. Based on the morphologies and shapes of the galaxy nuclei, we argue that most of these galaxies’ central regions contain secularly evolving components (pseudo-bulges), and in many cases we photometrically identify co-existing “classical” bulge components as well. Using these decompositions, we draw the following conclusions. (1) The megamaser BH masses span two orders of magnitude (106-{10}8 {M}⊙ ) while the stellar mass of their spiral host galaxies are all ˜ {10}11 {M}⊙ within a factor of three. (2) The BH masses at a given bulge mass or total stellar mass in the megamaser host spiral galaxies tend to be lower than expected when compared to an extrapolation of the BH-bulge relation based on early-type galaxies. (3) The observed large intrinsic scatter of BH masses in the megamaser host galaxies raises the question of whether scaling relations exist in spiral galaxies. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 12185.

  7. CO Linewidths and the Black Hole - Bulge Relationship for High Redshift QSOs

    NASA Astrophysics Data System (ADS)

    Menezes, K. L.; Shields, G. A.; Massart, C. A.; vanden Bout, P.

    2005-10-01

    Supermassive black holes in galactic nuclei have masses MBH related to the mass and velocity dispersion σ* of the host galaxy. We examine the MBH - σ* in high redshift QSOs, deriving MBH from the broad emission-line widths and σ* from the radio CO lines. At redshifts z = 4 to 6, gigantic black holes appear to exist in relatively modest galaxies.

  8. BLACK-HOLE-BULGE RELATIONSHIP OF POST-STARBURST QUASARS AT z {approx} 0.3

    SciTech Connect

    Hiner, Kyle D.; Canalizo, Gabriela; Wold, Margrethe; Brotherton, Michael S.; Cales, Sabrina L. E-mail: gabriela.canalizo@ucr.edu E-mail: mbrother@uwyo.edu

    2012-09-10

    The M{sub BH}-{sigma}{sub *} relation has been studied extensively for local galaxies, but to date there have been scarce few direct measurements of stellar velocity dispersions for systems beyond the local universe. We investigate black hole and host galaxy properties of six 'post-starburst quasars' (PSQs) at z {approx} 0.3. Spectra of these objects simultaneously display features from the active nucleus including broad emission lines and a host galaxy Balmer absorption series indicative of the post-starburst stellar population. These are the first measurements of {sigma}{sub *} in such objects, and we significantly increase the number of directly measured non-local objects on the M{sub BH}-{sigma}{sub *} diagram. The 'PSQs' of our sample fall on or above the locally defined M{sub BH}-{sigma}{sub *} relation, a result that is consistent with previous M{sub BH}-{sigma}{sub *} studies of samples at z > 0.1. However, they are generally consistent with the M{sub BH}-L{sub bulge} relation. Furthermore, their location on the Faber-Jackson relation suggests that some of the bulges may be dynamically peculiar.

  9. The Black Hole-Bulge Relationship for QSOs at High Redshift

    NASA Astrophysics Data System (ADS)

    Shields, G. A.; Menezes, K. L.; Massart, C. A.; Vanden Bout, P.

    2006-04-01

    We examine the black hole mass-galaxy bulge relationship in high-redshift QSOs. Black hole masses are derived from broad emission lines, and the host galaxy stellar velocity dispersion σ* is estimated from the widths of the radio CO emission lines. At redshifts z>3, the CO line widths are narrower than expected for the black hole mass, indicating that these giant black holes reside in undersized bulges by an order of magnitude or more. The largest black holes (MBH>109 Msolar) evidently grow rapidly in the early universe without commensurate growth of their host galaxies. CO line widths offer a unique opportunity to study AGN host galaxy dynamics at high redshift.

  10. The influence of mergers and ram-pressure stripping on black hole-bulge correlations

    NASA Astrophysics Data System (ADS)

    Ginat, Yonadav Barry; Meiron, Yohai; Soker, Noam

    2016-10-01

    We analyse the scatter in the correlation between supermassive black hole (SMBH) mass and bulge stellar mass of the host galaxy, and infer that it cannot be accounted for by mergers alone. The merger-only scenario, where small galaxies merge to establish a proportionality relation between the SMBH and bulge masses, leads to a scatter around the linear proportionality line that increases with the square root of the SMBH (or bulge) mass. By examining a sample of 103 galaxies, we find that the intrinsic scatter increases more rapidly than expected from the merger-only scenario. The correlation between SMBH masses and their host galaxy properties is therefore more likely to be determined by a negative feedback mechanism that is driven by an active galactic nucleus. We find, a hint, that some galaxies with missing stellar mass reside close to the centre of clusters and speculate that ram-pressure stripping of gas off the young galaxy as it moves near the cluster centre, might explain the missing stellar mass at later times.

  11. How black holes saved relativity

    NASA Astrophysics Data System (ADS)

    Prescod-Weinstein, Chanda

    2016-02-01

    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.

  12. Analytical Relativity of Black Holes

    NASA Astrophysics Data System (ADS)

    Damour, Thibault

    The successful detection and analysis of gravitational wave (GW) signals from coalescing binary black holes necessitates the accurate prior knowledge of the form of the GW signals. This knowledge can be acquired through a synergy between Analytical Relativity (AR) methods and Numerical Relativity (NR) ones. We describe here the most promising AR formalism for describing the motion and radiation of coalescing binary black holes, the Effective One Body (EOB) method, and discuss its comparison with NR simulations.

  13. Relative Deprivation, Rising Expectations, and Black Militancy

    ERIC Educational Resources Information Center

    Abeles, Ronald P.

    1976-01-01

    Investigates the role of relative deprivation (RD) and rising expectations (RE) as mediating variables between social structure and black militancy through secondary analyses of survey data of blacks living in Cleveland and Miami in the late 1960s. Alternative explanations and implications derived from the present data and the theories for the…

  14. Black hole based tests of general relativity

    NASA Astrophysics Data System (ADS)

    Yagi, Kent; Stein, Leo C.

    2016-03-01

    General relativity has passed all solar system experiments and neutron star based tests, such as binary pulsar observations, with flying colors. A more exotic arena for testing general relativity is in systems that contain one or more black holes. Black holes are the most compact objects in the Universe, providing probes of the strongest-possible gravitational fields. We are motivated to study strong-field gravity since many theories give large deviations from general relativity only at large field strengths, while recovering the weak-field behavior. In this article, we review how one can probe general relativity and various alternative theories of gravity by using electromagnetic waves from a black hole with an accretion disk, and gravitational waves from black hole binaries. We first review model-independent ways of testing gravity with electromagnetic/gravitational waves from a black hole system. We then focus on selected examples of theories that extend general relativity in rather simple ways. Some important characteristics of general relativity include (but are not limited to) (i) only tensor gravitational degrees of freedom, (ii) the graviton is massless, (iii) no quadratic or higher curvatures in the action, and (iv) the theory is four-dimensional. Altering a characteristic leads to a different extension of general relativity: (i) scalar-tensor theories, (ii) massive gravity theories, (iii) quadratic gravity, and (iv) theories with large extra dimensions. Within each theory, we describe black hole solutions, their properties, and current and projected constraints on each theory using black hole based tests of gravity. We close this review by listing some of the open problems in model-independent tests and within each specific theory.

  15. Linking the spin evolution of massive black holes to galaxy kinematics

    SciTech Connect

    Sesana, A.; Barausse, E.; Dotti, M.; Rossi, E. M. E-mail: barausse@iap.fr E-mail: emr@strw.leidenuniv.nl

    2014-10-20

    We present the results of a semianalytical model that evolves the masses and spins of massive black holes together with the properties of their host galaxies across the cosmic history. As a consistency check, our model broadly reproduces a number of observations, e.g., the cosmic star formation history; the black hole mass, luminosity, and galaxy mass functions at low redshift; the black hole-bulge mass relation; and the morphological distribution at low redshift. For the first time in a semianalytical investigation, we relax the simplifying assumptions of perfect coherency or perfect isotropy of the gas fueling the black holes. The dynamics of gas is instead linked to the morphological properties of the host galaxies, resulting in different spin distributions for black holes hosted in different galaxy types. We compare our results with the observed sample of spin measurements obtained through broad Kα iron line fitting. The observational data disfavor both accretion along a fixed direction and isotropic fueling. Conversely, when the properties of the accretion flow are anchored to the kinematics of the host galaxy, we obtain a good match between theoretical expectations and observations. A mixture of coherent accretion and phases of activity in which the gas dynamics is similar to that of the stars in bulges (i.e., with a significant velocity dispersion superimposed to a net rotation) best describes the data, adding further evidence in support of the coevolution of massive black holes and their hosts.

  16. Black-Brown Relations and Stereotypes.

    ERIC Educational Resources Information Center

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

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

  17. Black hole mergers: beyond general relativity

    NASA Astrophysics Data System (ADS)

    Stein, Leo; Okounkova, Maria

    2017-01-01

    One hundred years after the birth of general relativity, advanced LIGO has finally directly detected gravitational waves. The source: two black holes merging into one. Advanced LIGO will soon provide the opportunity to test GR, using gravitational waves, in the dynamical strong-field regime-a setting where GR has not yet been tested. GR has passed all weak-field tests with flying colors. Yet it should eventually break down, so we must look to the strong-field. To perform strong-field tests of GR, we need waveform models from theories beyond GR. To date there are no numerical simulations of black hole mergers in theories which differ from GR. The main obstacle is the mathematical one of well-posedness. I will explain how to overcome this obstacle, and demonstrate the success of this approach by presenting the first numerical simulations of black hole mergers in a theory beyond GR.

  18. Black Suburbanization: Has It Changed the Relative Location of Races?

    ERIC Educational Resources Information Center

    Galster, George C.

    1991-01-01

    Analyzes changes in relative decentralization for Blacks in 40 metropolitan statistical areas during the 1970s. Although there is substantial suburbanization among Blacks, measured conventionally, evidence implies that Blacks will gain little if job growth, high-quality education, and superior environments follow Whites as they move further into…

  19. Construction of regular black holes in general relativity

    NASA Astrophysics Data System (ADS)

    Fan, Zhong-Ying; Wang, Xiaobao

    2016-12-01

    We present a general procedure for constructing exact black hole solutions with electric or magnetic charges in general relativity coupled to a nonlinear electrodynamics. We obtain a variety of two-parameter family spherically symmetric black hole solutions. In particular, the singularity at the center of the space-time can be canceled in the parameter space and the black hole solutions become regular everywhere in space-time. We study the global properties of the solutions and derive the first law of thermodynamics. We also generalize the procedure to include a cosmological constant and construct regular black hole solutions that are asymptotic to anti-de Sitter space-time.

  20. Astrophysical phenomena related to supermassive black holes

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2006-12-01

    reactions in stars. In the most active galaxies known, the radiating accretion disc of the central SMBH engine easily outshines the stellar light of the entire galaxy (Blandford 1995). In addition to the light, plasma streams can emerge from the innermost regions at relativistic velocities, returning energy to the host galaxy (host) and creating jets and lobes with strong observational signatures, especially at radio and X-ray wavelengths (Wilson 2003). New insights in the wide field of SMBH/host interaction are often related to the development of new, more sensitive instruments and telescopes. For example the idea, that a high luminosity AGN may result from a merger event between two galaxies, could only develop with the upcoming high resolution and sensitive imaging capabilities needed to detect the highly distorted host galaxy morphologies of (post-)merger galaxies (Heckman et al. 1986). Furthermore multi-wavelength approaches, which combine the results of measurements at different wavelengths, often lead to new conclusions or confirm unsecured hypotheses. Thus developing a new instrument can be as valuable as combining different datasets. I follow both approaches and developed projects which (i) deal with new instrumentation and telescope technology, (ii) combine datasets from different wavelengths and resolutions, and (iii) incorporate recent theoretical models and predictions, which can be verified empirically. While some projects are more focused on investigating the power of new observational techniques, others incorporate acknowledged instruments to probe predictions based on previous observations and models and trace special phenomena of SMBH/host interaction. But in most cases aspects of all three items appear. The SMBH/host interaction results in phenomena at all linear size scales of the system, from the direct accretion of matter onto the central black hole up to radio jets crossing the entire galaxy. Thus interaction effects do not simply concentrate on the

  1. Numerical Relativity, Black Hole Mergers, and Gravitational Waves: Part II

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2012-01-01

    This series of 3 lectures will present recent developments in numerical relativity, and their applications to simulating black hole mergers and computing the resulting gravitational waveforms. In this second lecture, we focus on simulations of black hole binary mergers. We hig hlight the instabilities that plagued the codes for many years, the r ecent breakthroughs that led to the first accurate simulations, and the current state of the art.

  2. Following Black Hole Scaling Relations through Gas-rich Mergers

    NASA Astrophysics Data System (ADS)

    Medling, Anne M.; U, Vivian; Max, Claire E.; Sanders, David B.; Armus, Lee; Holden, Bradford; Mieda, Etsuko; Wright, Shelley A.; Larkin, James E.

    2015-04-01

    We present black hole mass measurements from kinematic modeling of high-spatial resolution integral field spectroscopy of the inner regions of nine nearby (ultra-)luminous infrared galaxies in a variety of merger stages. These observations were taken with OSIRIS and laser guide star adaptive optics on the Keck I and Keck II telescopes, and reveal gas and stellar kinematics inside the spheres of influence of these supermassive black holes. We find that this sample of black holes are overmassive (˜107-9 {{M}}) compared to the expected values based on black hole scaling relations, and suggest that the major epoch of black hole growth occurs in early stages of a merger, as opposed to during a final episode of quasar-mode feedback. The black hole masses presented are the dynamical masses enclosed in ˜25 pc, and could include gas which is gravitationally bound to the black hole but has not yet lost sufficient angular momentum to be accreted. If present, this gas could in principle eventually fuel active galactic nucleus feedback or be itself blown out from the system.

  3. Stereotypes of Black American Women Related to Sexuality and Motherhood.

    PubMed

    Rosenthal, Lisa; Lobel, Marci

    2016-09-01

    Intersectionality theorists and researchers suggest the importance of examining unique stereotypes associated with intersecting group identities. We focus on the unique stereotypes of Black women in the United States related to sexuality and motherhood. In an online experimental study, 435 undergraduates from a Northeastern U.S. university were randomly assigned to one of the four conditions in which they viewed a photograph and read a description of a target young woman. The target's race (Black vs. White) and pregnancy status (pregnant vs. no pregnancy information) were varied. A Black female target (pregnant or not) was perceived more negatively on items related to historically rooted societal stereotypes about sexual activity, sexual risk, motherhood status, and socioeconomic status than was a White female target, but there were no differences on items unrelated to societal stereotypes. A Black target described as pregnant was also perceived as more likely to be a single mother and to need public assistance than was a White target described as pregnant. Current findings, along with evidence that societal stereotypes have damaging effects, underscore the importance of diversifying images of Black women and increasing awareness of how stereotypes affect perceptions of Black women. Findings also highlight the value of research employing intersectionality to understand stereotypes.

  4. Black-Hole Binaries, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Kelly, Bernard J.; Centrella, Joan; Baker, John G.; Kelly, Bernard J.; vanMeter, James R.

    2010-01-01

    Understanding the predictions of general relativity for the dynamical interactions of two black holes has been a long-standing unsolved problem in theoretical physics. Black-hole mergers are monumental astrophysical events ' releasing tremendous amounts of energy in the form of gravitational radiation ' and are key sources for both ground- and spacebased gravitational wave detectors. The black-hole merger dynamics and the resulting gravitational waveforms can only he calculated through numerical simulations of Einstein's equations of general relativity. For many years, numerical relativists attempting to model these mergers encountered a host of problems, causing their codes to crash after just a fraction of a binary orbit cnuld be simulated. Recently ' however, a series of dramatic advances in numerical relativity has ' for the first time, allowed stable / robust black hole merger simulations. We chronicle this remarkable progress in the rapidly maturing field of numerical relativity, and the new understanding of black-hole binary dynamics that is emerging. We also discuss important applications of these fundamental physics results to astrophysics, to gravitationalwave astronomy, and in other areas.

  5. Numerical Relativity, Black Hole Mergers, and Gravitational Waves: Part III

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2012-01-01

    This series of 3 lectures will present recent developments in numerical relativity, and their applications to simulating black hole mergers and computing the resulting gravitational waveforms. In this third and final lecture, we present applications of the results of numerical relativity simulations to gravitational wave detection and astrophysics.

  6. Numerical Relativity, Black Hole Mergers, and Gravitational Waves: Part I

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2012-01-01

    This series of 3 lectures will present recent developments in numerical relativity, and their applications to simulating black hole mergers and computing the resulting gravitational waveforms. In this first lecture, we introduce the basic ideas of numerical relativity, highlighting the challenges that arise in simulating gravitational wave sources on a computer.

  7. Numerical Relativity Simulations for Black Hole Merger Astrophysics

    NASA Technical Reports Server (NTRS)

    Baker, John G.

    2010-01-01

    Massive black hole mergers are perhaps the most energetic astronomical events, establishing their importance as gravitational wave sources for LISA, and also possibly leading to observable influences on their local environments. Advances in numerical relativity over the last five years have fueled the development of a rich physical understanding of general relativity's predictions for these events. Z will overview the understanding of these event emerging from numerical simulation studies. These simulations elucidate the pre-merger dynamics of the black hole binaries, the consequent gravitational waveform signatures ' and the resulting state, including its kick velocity, for the final black hole produced by the merger. Scenarios are now being considered for observing each of these aspects of the merger, involving both gravitational-wave and electromagnetic astronomy.

  8. Merging Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan M.

    2009-01-01

    The final merger of two black holes will emit more energy than all the stars in the observable universe combined. This energy will come in the form of gravitational waves, which are a key prediction of Einstein's general relativity and a new tool for exploring the universe. Observing these mergers with gravitational wave detectors, such as the ground-based LIGO and the space-based LISA, requires knowledge of the radiation waveforms. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes were long plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and w aefo rms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

  9. Overview of EPA activities and research related to black carbon

    EPA Science Inventory

    The purpose of this international presentation is to give an overview of EPA activities related to black carbon (BC). This overview includes some summary information on how EPA defines BC, current knowledge on United States emissions and forecasted emission reductions, and ongoin...

  10. Uncertainty relation and black hole entropy of Kerr spacetime

    NASA Astrophysics Data System (ADS)

    Hu, Shuang-Qi; Zhao, Ren

    2005-07-01

    The properties of thermal radiation are discussed by using a new equation of state density, which is motivated by the generalized uncertainty relation in the quantum gravity. There is no burst at the last stage of the emission of Kerr black hole. When the new equation of state density is utilized to investigate the entropy of a Bosonic field and Fermionic field outside the horizon of a static Kerr black hole, the divergence appearing in the brick wall model is removed, without any cutoff. The entropy proportional to the horizon area is derived from the contribution of the vicinity of the horizon.

  11. Rotating black holes in the teleparallel equivalent of general relativity

    NASA Astrophysics Data System (ADS)

    Nashed, Gamal G. L.

    2016-05-01

    We derive set of solutions with flat transverse sections in the framework of a teleparallel equivalent of general relativity which describes rotating black holes. The singularities supported from the invariants of torsion and curvature are explained. We investigate that there appear more singularities in the torsion scalars than in the curvature ones. The conserved quantities are discussed using Einstein-Cartan geometry. The physics of the constants of integration is explained through the calculations of conserved quantities. These calculations show that there is a unique solution that may describe true physical black hole.

  12. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, John

    2007-01-01

    The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GE0600, as well as the space-based interferometer LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, data analysis, and astrophysics.

  13. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2007-01-01

    This viewgraph presentation reviews the massive black hole (MBH) binaries that are found at the center of most galaxies, "astronomical messenger", gravitational waves (GW), and the use of numerical relativity understand the features of these phenomena. The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity.. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  14. Binary black holes, gravitational waves, and numerical relativity

    NASA Astrophysics Data System (ADS)

    Centrella, Joan M.; Baker, John G.; Boggs, William D.; Kelly, Bernard J.; McWilliams, Sean T.; van Meter, James R.

    2007-07-01

    The final merger of comparable mass binary black holes produces an intense burst of gravitational radiation and is one of the strongest sources for both ground-based and space-based gravitational wave detectors. Since the merger occurs in the strong-field dynamical regime of general relativity, numerical relativity simulations of the full Einstein equations in 3-D are required to calculate the resulting gravitational dynamics and waveforms. While this problem has been pursued for more than 30 years, the numerical codes have long been plagued by various instabilities and, overall, progress was incremental. Recently, however, dramatic breakthrough have occurred, resulting in robust simulations of merging black holes. In this paper, we examine these developments and the exciting new results that are emerging.

  15. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2008-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields. We need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  16. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2006-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. This situation has changed dramatically in the past year, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LISA and LIGO.

  17. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2007-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA

  18. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2008-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  19. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2008-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities. causing them to crash well before the black hole:, in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  20. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2009-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  1. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2007-01-01

    The final merger of two black holes releases a tremendous amount of energy and is one of the brightest sources in the gravitational wave sky. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This talk will take you on this quest for the holy grail of numerical relativity, showing how a spacetime is constructed on a computer to build a simutation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LIGO and LISA.

  2. Binary Black Holes, Gravitational Waves, and Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2007-01-01

    Massive black hole (MBH) binaries are found at the centers of most galaxies. MBH mergers trace galaxy mergers and are strong sources of gravitational waves. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. Since these mergers take place in regions of very strong gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these waveforms. For more than 30 years, scientists have tried to compute these waveforms using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities. causing them to crash well before the black hole:, in the binary could complete even a single orbit. Recently this situation has changed dramatically, with a series of amazing breakthroughs. This presentation shows how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. Focus is on the recent advances that that reveal these waveforms, and the potential for discoveries that arises when these sources are observed by LIGO and LISA.

  3. A Prime Assessment for Black Colleges: Role of Blacks in the Sciences and Related Fields.

    ERIC Educational Resources Information Center

    Branson, Herman

    1978-01-01

    This article examines the need for blacks in science and engineering. From a review of the history of blacks as objects of scientific study from the 1790s to the present a better grasp of the problems confronting blacks can be gained by examining two fields: genetics and psychology. In genetic research on blacks, the results are used not by…

  4. Binary Black Holes, Numerical Relativity, and Gravitational Waves

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2007-01-01

    The final merger of two black holes releases a tremendous amount of energy, more than the combined light from all the stars in the visible universe. This energy is emitted in the form of gravitational waves, and observing these sources with gravitational wave detectors such as LISA requires that we know the pattern or fingerprint of the radiation emitted. Since black hole mergers take place in regions of extreme gravitational fields, we need to solve Einstein's equations of general relativity on a computer in order to calculate these wave patterns. For more than 30 years, scientists have tried to compute these wave patterns. However, their computer codes have been plagued by problems that caused them to crash. This situation has changed dramatically in the past 2 years, with a series of amazing breakthroughs. This talk will take you on this quest for these gravitational wave patterns, showing how a spacetime is constructed on a computer to build a simulation laboratory for binary black hole mergers. We will focus on the recent advances that are revealing these waveforms, and the dramatic new potential for discoveries that arises when these sources will be observed by LISA

  5. Theoretical re-evaluations of the black hole mass-bulge mass relation - I. Effect of seed black hole mass

    NASA Astrophysics Data System (ADS)

    Shirakata, Hikari; Kawaguchi, Toshihiro; Okamoto, Takashi; Makiya, Ryu; Ishiyama, Tomoaki; Matsuoka, Yoshiki; Nagashima, Masahiro; Enoki, Motohiro; Oogi, Taira; Kobayashi, Masakazu A. R.

    2016-10-01

    We explore the effect of varying the mass of a seed black hole on the resulting black hole mass-bulge mass relation at z ˜ 0, using a semi-analytic model of galaxy formation combined with large cosmological N-body simulations. We constrain our model by requiring that the observed properties of galaxies at z ˜ 0 are reproduced. In keeping with previous semi-analytic models, we place a seed black hole immediately after a galaxy forms. When the mass of the seed is set at 105 M⊙, we find that the model results become inconsistent with recent observational results of the black hole mass-bulge mass relation for dwarf galaxies. In particular, the model predicts that bulges with ˜109 M⊙ harbour larger black holes than observed. On the other hand, when we employ seed black holes of 103 M⊙ or select their mass randomly within a 103-5 M⊙ range, the resulting relation is consistent with observation estimates, including the observed dispersion. We find that, to obtain stronger constraints on the mass of seed black holes, observations of less massive bulges at z ˜ 0 are a more powerful comparison than the relations at higher redshifts.

  6. Relative Earnings of Black Men to White Men by Region, Industry.

    ERIC Educational Resources Information Center

    Saunders, Lisa

    1995-01-01

    The earnings gap between black men and white men widened from 1979-89. Black men were more likely to experience declines in regions where they were concentrated. White men's earnings rose relative to black men's in lower-paying industries. (SK)

  7. Competition, Conflict, and Coalitions: Black-Latino/a Relations within Institutions of Higher Education

    ERIC Educational Resources Information Center

    Literte, Patricia E.

    2011-01-01

    This case study examines Black-Latino/a relations at a public university in California, which has a 31% Black and 40% Latino/a student population. In-depth interviews with students and administrators indicate that Black and Latino/a students do recognize that they share similar educational and socioeconomic obstacles; however, there is little to…

  8. Photonic devices based on black phosphorus and related hybrid materials

    NASA Astrophysics Data System (ADS)

    Vitiello, M. S.; Viti, L.

    2016-08-01

    Artificial semiconductor heterostructures played a pivotal role in modern electronic and photonic technologies, providing a highly effective means for the manipulation and control of carriers, from the visible to the far-infrared, leading to the development of highly efficient devices like sources, detectors and modulators. The discovery of graphene and the related fascinating capabilities have triggered an unprecedented interest in devices based on inorganic two-dimensional (2D) materials. Amongst them, black phosphorus (BP) recently showed an extraordinary potential in a variety of applications across micro-electronics and photonics. With an energy gap between the gapless graphene and the larger gap transition metal dichalcogenides, BP can form the basis for a new generation of high-performance photonic devices that could be specifically engineered to comply with different applications, like transparent saturable absorbers, fast photocounductive switches and low noise photodetectors, exploiting its peculiar electrical, thermal and optical anisotropy. This paper will review the latest achievements in black-phosphorus-based THz photonics and discuss future perspectives of this rapidly developing research field.

  9. Black/Brown/White Relations: Race Relations in the 1970s.

    ERIC Educational Resources Information Center

    Willie, Charles V., Ed.

    The collection of papers in this book present an analysis of the effects of institutional racism on all races. The first part of the book deals with seeking definitions of the race problem and explores the various facets of race relations in the 1970s, including: (1) the black view of a national population policy and the fear of racial genocide;…

  10. Generalized Uncertainty Relation and Hawking Radiation of the Black Hole

    NASA Astrophysics Data System (ADS)

    Zhao, Ren; Zhang, Lichun; Wu, Yueqin; Li, Huaifan

    2009-08-01

    Recently, there has been much attention devoted to the correction to the black hole radiation spectrum and the quantum corrections to Bekenstein-Hawking entropy. In particular, many researchers have expressed a vested interest in the coefficient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the radiation spectrum of arbitrary dimension Schwarzschild black hole after considering the generalized uncertainty principle. The correction value of Bekenstein-Hawking entropy is derived.

  11. LOW-MASS AGNs AND THEIR RELATION TO THE FUNDAMENTAL PLANE OF BLACK HOLE ACCRETION

    SciTech Connect

    Gültekin, Kayhan; King, Ashley L.; Miller, Jon M.; Cackett, Edward M.; Pinkney, Jason

    2014-06-20

    We put active galactic nuclei (AGNs) with low-mass black holes on the fundamental plane of black hole accretion—the plane that relates X-ray emission, radio emission, and mass of an accreting black hole—to test whether or not the relation is universal for both stellar-mass and supermassive black holes. We use new Chandra X-ray and Very Large Array radio observations of a sample of black holes with masses less than 10{sup 6.3} M {sub ☉}, which have the best leverage for determining whether supermassive black holes and stellar-mass black holes belong on the same plane. Our results suggest that the two different classes of black holes both belong on the same relation. These results allow us to conclude that the fundamental plane is suitable for use in estimating supermassive black hole masses smaller than ∼10{sup 7} M {sub ☉}, in testing for intermediate-mass black holes, and in estimating masses at high accretion rates.

  12. Black Students of United Methodist-Related Colleges and Universities: An Enrollment Profile.

    ERIC Educational Resources Information Center

    Yamada, Ken

    United Methodist-related colleges and universities maintained black enrollment at 9 percent of the total student body consistently during the period 1976-80, keeping pace with the growth in overall enrollment. Many institutions showed a decline in black student enrollment in 1978, with a significant increase in 1980, particularly in the…

  13. Attitudes about Male-Female Relations among Black Adolescents.

    ERIC Educational Resources Information Center

    Rubin, Roger H.

    1981-01-01

    Examines the relationship of family structure, peer group affiliation, social class, and sex with five dependent variables concerned with attitudes toward dating values, marriage, romanticism, premarital pregnancy, and premarital sexual permissiveness among 85 rural, Black adolescent males and females. Findings suggest general community norms and…

  14. White and Black Teachers' Job Satisfaction: Does Relational Demography Matter?

    ERIC Educational Resources Information Center

    Fairchild, Susan; Tobias, Robert; Corcoran, Sean; Djukic, Maja; Kovner, Christine; Noguera, Pedro

    2012-01-01

    Data on the impact of student, teacher, and principal racial and gender composition in urban schools on teacher work outcomes are limited. This study, a secondary data analysis of White and Black urban public school teachers using data taken from the restricted use 2003-04 Schools and Staffing Survey (SASS), examines the effects of relational…

  15. Blacks in Science and Related Disciplines. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Sammons, Vivian O., Comp.; Dempsey, Denise P., Comp.

    Humankind had its beginnings in Africa. Imhotep, the first scientist, was a man of color, an Egyptian. Africans made great strides in science and medicine prior to slavery. In the United States, blacks have contributed much to the advancement of science and invention; however, history for the most part has not given them credit for these…

  16. Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes

    NASA Astrophysics Data System (ADS)

    Liu, Hang; Meng, Xin-he

    2017-02-01

    Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions d≥4, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter a j = 0 in higher dimensions d≥5, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge δ=0. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotating Kaluza-Klein black holes in asymptotically flat spacetime act the same way, it is found that the charge has no effect in the angular momentum-independence of entropy sum and product in asymptotically flat spactime.

  17. Angular Momentum-Free of the Entropy Relations for Rotating Kaluza-Klein Black Holes

    NASA Astrophysics Data System (ADS)

    Liu, Hang; Meng, Xin-he

    2016-11-01

    Based on a mathematical lemma related to the Vandermonde determinant and two theorems derived from the first law of black hole thermodynamics, we investigate the angular momentum independence of the entropy sum as well as the entropy product of general rotating Kaluza-Klein black holes in higher dimensions. We show that for both non-charged rotating Kaluza-Klein black holes and non-charged rotating Kaluza-Klein-AdS black holes, the angular momentum of the black holes will not be present in entropy sum relation in dimensions d≥4, while the independence of angular momentum of the entropy product holds provided that the black holes possess at least one zero rotation parameter a j = 0 in higher dimensions d≥5, which means that the cosmological constant does not affect the angular momentum-free property of entropy sum and entropy product under the circumstances that charge δ=0. For the reason that the entropy relations of charged rotating Kaluza-Klein black holes as well as the non-charged rotating Kaluza-Klein black holes in asymptotically flat spacetime act the same way, it is found that the charge has no effect in the angular momentum-independence of entropy sum and product in asymptotically flat spactime.

  18. RELATION BETWEEN GLOBULAR CLUSTERS AND SUPERMASSIVE BLACK HOLES IN ELLIPTICALS AS A MANIFESTATION OF THE BLACK HOLE FUNDAMENTAL PLANE

    SciTech Connect

    Snyder, Gregory F.; Hernquist, Lars; Hopkins, Philip F.

    2011-02-10

    We analyze the relation between the mass of the central supermassive black hole (M{sub BH}) and the number of globular clusters (N{sub GC}) in elliptical galaxies and bulges as a ramification of the black hole fundamental plane, the theoretically predicted and observed multi-variable correlation between M{sub BH} and bulge binding energy. Although the tightness of the M{sub BH}-N{sub GC} correlation suggests an unlikely causal link between supermassive black holes and globular clusters (GCs), such a correspondence can exhibit small scatter even if the physical relationship is indirect. We show that the relatively small scatter of the M{sub BH}-N{sub GC} relation owes to the mutual residual correlation of M{sub BH} and N{sub GC} with stellar mass when the velocity dispersion is held fixed. Thus, present observations lend evidence for feedback-regulated models in which the bulge binding energy is most important; they do not necessarily imply any 'special' connection between GCs and M{sub BH}. This raises the question of why N{sub GC} traces the formation of ellipticals and bulges sufficiently well to be correlated with binding energy.

  19. Area functional relation for 5D-Gauss-Bonnet-AdS black hole

    NASA Astrophysics Data System (ADS)

    Pradhan, Parthapratim

    2016-08-01

    We present area (or entropy) functional relation for multi-horizons five dimensional (5D) Einstein-Maxwell-Gauss-Bonnet-AdS black hole. It has been observed by exact and explicit calculation that some complicated function of two or three horizons area is mass-independent whereas the entropy product relation is not mass-independent. We also study the local thermodynamic stability of this black hole. The phase transition occurs at certain condition. Smarr mass formula and first law of thermodynamics have been derived. This mass-independent relation suggests they could turn out to be an universal quantity and further helps us to understanding the nature of black hole entropy (both interior and exterior) at the microscopic level. In the "Appendix", we have derived the thermodynamic products for 5D Einstein-Maxwell-Gauss-Bonnet black hole with vanishing cosmological constant.

  20. Problems related to gravitational waves from binary black holes

    NASA Astrophysics Data System (ADS)

    Tsokaros, Antonios A.

    With three gravitational wave observatories LIGO, GEO, and TAMA in operation the dawn of gravitational wave astronomy is nearly a reality. In the coming decade these earth-based observatories together with the expected space-based, LISA will play a major role in advancing our knowledge of our cosmic habitat. The first targets for gravitational wave detectors like LIGO are the waves emitted by pairs of compact objects (neutron stars and black holes) that orbit each other. Developing an accurate numerical model for these binary coalescence is crucial to maximize the number of events that the gravitational-wave detectors will see and to extract from observed events the physics of the coalescing objects. The first step in studying the dynamics of this sort is to obtain astrophysically realistic initial data sets that represent such binaries. Although for the binary neutron stars that is already achieved, things have proven to be more difficult for the binary black hole case. In this study we analyze Einstein's equations in the presence of a helical killing vector and try to obtain initial data sets by solving five, instead of four, semi-elliptic equations. For the background metric we assumed a linear superposition of two Kerr metrics written in the Kerr-Schild form. A new computational technique with overlapping spherical domains for the solution of such semi-elliptic equations for two black holes of different masses was developed. In addition, motivated by the necessity of predicting realistic waveforms, we investigate the self-force experienced by a static non-minimally-coupled scalar charge outside a Schwarzschild black hole. We find that the finite part of this self-force is zero. To arrive at this result, we employ a Gedankenexperiment where the force is determined from the work required to slowly raise or lower the particle an infinitesimal distance. Our no-self-force result is in disagreement with a previous result of Zel'nikov and Frolov, who have suggested

  1. Relation between CO and Black Carbon from Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Park, S. S.; Kim, J.; Lim, H.; Mok, J.

    2014-12-01

    The Black Carbon (BC) is designated by one of the potential factor for global warming (IPCC, 2007). Furthermore, carbon monoxide (CO) is also important gas to modify chemical, physical and climatological properties of tropospheric chemistry. Both CO and carbonaceous aerosol, especial to the black carbon, are similar emission sources, fuel combustion and biomass burning. Previously, the MODIS-OMI algorithm (MOA) identified the BC amount and its location by using Angstrom Exponent (AE) from MODIS and Aerosol Index (AI) from OMI. In addition, the CO amount has been traced by the Measurement of Pollution in the Troposphere (MOPITT) since 1999. Therefore, the correlation between the AOD of BC (AODBC) and total column densities of CO (TCDCO) can be estimated by MOA and MOPITT. The correlation between AODBC and TCDCO becomes better than that between fine mode AOD and TCDCO in most global regions. Highly correlated case is the region with biomass burning and wild fires. In Southern Africa, however, the correlation coefficient between AODBC and TCDCO is lower than those between fine mode AOD and TCDCO. It is explained by the characteristics of wind fields, sources of aerosols, and distance from the source regions from the difference in the correlation. The results from correlation studies propose the possibilities that CO can be used as surrogates of BC and reference of the validation for the aerosol classification algorithm of BC from satellite measurements.

  2. Black-White Differences in Attitudes Related to Pregnancy among Young Women1

    PubMed Central

    Barber, Jennifer S.; Yarger, Jennifer Eckerman; Gatny, Heather H.

    2015-01-01

    In this paper we use newly available data from the Relationship Dynamics and Social Life (RDSL) study to compare a wide range of attitudes related to pregnancy for 961 Black and white young women. We also investigate the extent to which race differences are mediated by, or net of, family background, childhood socioeconomic status, adolescent experiences related to pregnancy, and current socioeconomic status. Black women are less positive, in general, than white women, toward young non-marital sex, contraception, and childbearing, and have less desire for sex in the upcoming year. This is largely because Black women are more religious than white women, and in part because they are more socioeconomically disadvantaged in young adulthood. However, in spite of these less positive attitudes, Black women are more likely to expect sex without contraception in the next year, and to expect more positive consequences if they were to become pregnant, relative to white women. This is largely because, relative to white women, Black women have higher rates of sex without contraception in adolescence, and in part because they are more likely to have grown up with a single parent. It is unclear whether attitudes toward contraception and pregnancy preceded or are a consequence of adolescent sex without contraception. Some race differences remain unexplained – net of all potential mediators in our models, Black women have less desire for sex in the upcoming year, but are less willing to refuse to have sex with a partner if they think it would make him angry, and expect more positive personal consequences of a pregnancy, relative to white women. In spite of these differences, Black women's desires to achieve and to prevent pregnancy are very similar to white women's desires. PMID:25962867

  3. Economic losses related to internal diseases in Japanese black cattle.

    PubMed

    Inoue, Keiichi; Honda, Takeshi; Oyama, Kenji

    2016-05-01

    The objective of this study was to estimate the direct economic losses due to the condemnation of the liver and large intestine because of internal diseases (multifocal necrosis in the liver (MNL) and inflammation of the large intestine (ILI)), and the indirect losses because of reductions in carcass performance from MNL, bovine abdominal fat necrosis (BFN) and ILI using data from 5383 Japanese Black cattle. Direct losses were estimated by multiplying the price of the condemned part by the frequency of its occurrence owing to the disease. Similarly, indirect losses were estimated as the product of unit carcass price and reduction in carcass weight (CW) due to the disease. The direct impact on the beef cattle industry from MNL and ILI was estimated at around $1.29 million (US$1 = ¥120) per year. A least-squares analysis showed that MNL had no influence on any carcass trait, whereas BFN and ILI significantly reduced CW, rib eye area and darkened the beef. ILI also reduced rib thickness. The indirect losses from BFN and ILI were estimated as a maximum of $131.7 and $256.4 per animal and around $6.26 million and $4.03 million for the industry, respectively, mostly because of the reduction in CW.

  4. Algebraically special space-time in relativity, black holes, and pulsar models

    NASA Technical Reports Server (NTRS)

    Adler, R. J.; Sheffield, C.

    1973-01-01

    The entire field of astronomy is in very rapid flux, and at the center of interest are problems relating to the very dense, rotating, neutron stars observed as pulsars. the hypothesized collapsed remains of stars known as black holes, and quasars. Degenerate metric form, or Kerr-Schild metric form, was used to study several problems related to intense gravitational fields.

  5. Energy-Related Indicators and Breast Cancer Risk among White and Black Women.

    PubMed

    Sanderson, Maureen; Lipworth, Loren; Shen-Miller, David; Nechuta, Sarah; Beeghly-Fadiel, Alicia; Shrubsole, Martha J; Zheng, Wei

    2015-01-01

    Energy-related indicators, including physical activity, energy intake, body mass index (BMI) and adult weight change, have been linked to breast cancer risk. Very few studies of these associations have been conducted among black women, therefore we used the Nashville Breast Health Study (NBHS) to determine whether similar effects were seen in black and white women. The NBHS is a population-based case-control study of breast cancer among women age 25 to 75 years conducted between 2001 and 2010 in and around the Nashville Metropolitan area. Telephone interviews and self-administered food frequency questionnaires were completed with 2,614 incident breast cancer cases ascertained through hospitals and the statewide cancer registry, and 2,306 controls selected using random digit dialing. Among premenopausal white and black women, there was little effect of adult exercise or other energy-related indicators on breast cancer risk, regardless of tumor estrogen receptor (ER) status. The beneficial effect of adult exercise on postmenopausal breast cancer appeared to be comparable between white and black women (highest tertile relative to none - white odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-1.0, p for trend=0.05; black OR 0.7, 95% CI 0.4-1.1, p for trend=0.07); however, among black women the reduction was limited to those with ER-positive disease. White and black women should be encouraged to engage in more physical activity to reduce their risk of postmenopausal breast cancer.

  6. Numerical Relativity and Black Hole Binaries: The historical path to present simulations

    NASA Astrophysics Data System (ADS)

    Laguna, Pablo

    2012-03-01

    The numerical relativity landscape at the turn of the century reached a unique transformative moment. A time with the ripe conditions to solve one of the grand challenges in computational physics: the two-body problem in general relativity. The computational modeling of two black holes as they coalesce is a formidable undertaking, requiring the most powerful hardware, innovative algorithms and creativity. This talk provides a historical perspective of the developments that led to the current success we enjoy of binary black hole simulations as genuine tools of discovery in the new astronomy of gravitational waves.

  7. Relating black carbon content to reduction of snow albedo

    NASA Astrophysics Data System (ADS)

    Brandt, R. E.; Warren, S. G.; Clarke, A. D.

    2011-12-01

    In remote snow of the Northern Hemisphere, the levels of soot pollution are in the parts-per-billion (ppb) range, where the effect on albedo is at the level of a few percent. A reduction of albedo by 1-2% is significant for climate but is difficult to detect experimentally, because snow albedo depends on several other variables. In our work to quantify the climatic effect of black carbon (BC) in snow, we therefore do not directly measure the albedo reduction. Instead, we use a two-step procedure: (1) We collect snow samples, melt and filter them, and analyze the filters spectrophotometrically for BC concentration. (2) We use the BC amount from the filter measurement, together with snow grain size, in a radiative transfer model to compute the albedo reduction. Our radiative transfer model uses the discrete ordinates algorithm DISORT 2.0. We have chosen a representative BC size distribution and optical constants, and have incorporated those of mineral dust as well. While a given mass of BC causes over an order of magnitude more snow albedo reduction compared to dust, a snowpack containing dust mutes the albedo-reducing effect of BC. Because the computed reduction of snow albedo is model-based, it requires experimental verification. We doubt that direct measurement of albedo-reduction will be feasible in nature, because of the vertical variation of both snow grain size and soot content, and because the natural soot content is small. We conclude that what is needed is an artificial snowpack, with uniform grain size and large uniform soot content (ppm not ppb), to produce a large signal on albedo. We have chosen to pursue this experiment outdoors rather than in the laboratory, for the following reasons: (1) The snowpack in the field of view is uniformly illuminated if the source of radiation is the Sun. (2) Visible radiation penetrates into the snow, so photons emerge horizontally distant from where they entered. In the limited width of a laboratory snowpack, radiation

  8. Mixed Layer Depth in the Aegean, Marmara, Black and Azov Seas: Part II: Relation to the Sonic Layer Depth

    DTIC Science & Technology

    2009-03-03

    r.com/ locate / jmarsysMixed layer depth in the Aegean, Marmara, Black and Azov Seas : Part II: Relation to the sonic layer depth Robert W. Helber a...index terms: The Aegean Sea The Black Sea The Azov Sea Keywords: Sound transmission Mixed layer depth Climatologyt analysis of the seasonal evolution of...the sonic layer depth (SLD) relative to the mixed layer depth (MLD) for the Aegean, Marmara, Black, and Azov Seas . SLD identifies the acoustic ducting

  9. Health-Related Quality of Life and Health-Promoting Behaviors in Black Men

    ERIC Educational Resources Information Center

    Calvert, Wilma J.; Isaac,, E. Paulette; Johnson, Sharon

    2012-01-01

    This study examined the health-related quality of life and health-promoting behaviors in a convenience sample of low-income black men. Almost three-fourths reported their overall health as good or better. However, the mean number of recent (that is, past 30 days) mentally unhealthy days was 13.12, and more than half reported frequent (greater than…

  10. Audiovisual Records in the National Archives Relating to Black History. Preliminary Draft.

    ERIC Educational Resources Information Center

    Waffen, Leslie; And Others

    A representative selection of the National Archives and Records Services' audiovisual collection relating to black history is presented. The intention is not to provide an exhaustive survey, but rather to indicate the breadth and scope of materials available for study and to suggest areas for concentrated research. The materials include sound…

  11. Race Relations Stories: How Southeast Asian Refugees Interpret the Ancestral Narration of Black and White Peers

    ERIC Educational Resources Information Center

    Hein, Jeremy; Moore, Christopher D.

    2009-01-01

    The contact hypothesis (Allport 1954) predicts that cross-racial interaction can produce social bonding under certain status, relational, and institutional conditions. We extend this classic theory on ingroups and outgroups using qualitative data on Cambodian and Hmong refugees' recollections of casual conversations about ancestry with black and…

  12. Racism-Related Stress, General Life Stress, and Psychological Functioning among Black American Women

    ERIC Educational Resources Information Center

    Pieterse, Alex L.; Carter, Robert T.; Ray, Kilynda V.

    2013-01-01

    The relationship between general life stress, perceived racism, and psychological functioning was explored in a sample of 118 Black American women. Findings indicate that racism-related stress was not a significant predictor of psychological functioning when controlling for general life stress. Perceived racism was positively associated with…

  13. Black hole radiation with modified dispersion relation in tunneling paradigm: free-fall frame

    NASA Astrophysics Data System (ADS)

    Wang, Peng; Yang, Haitang; Ying, Shuxuan

    2016-01-01

    Due to the exponential high gravitational red shift near the event horizon of a black hole, it might appear that the Hawking radiation would be highly sensitive to some unknown high energy physics. To study the effects of any unknown physics at the Planck scale on the Hawking radiation, the dispersive field theory models have been proposed, which are variations of Unruh's sonic black hole analogy. In this paper, we use the Hamilton-Jacobi method to investigate the dispersive field theory models. The preferred frame is the free-fall frame of the black hole. The dispersion relation adopted agrees with the relativistic one at low energy but is modified near the Planck mass mp. The corrections to the Hawking temperature are calculated for massive and charged particles to {O}( mp^{-2}) and neutral and massless particles with λ =0 to all orders. The Hawking temperature of radiation agrees with the standard one at the leading order. After the spectrum of radiation near the horizon is obtained, we use the brick wall model to compute the thermal entropy of a massless scalar field near the horizon of a 4D spherically symmetric black hole and a 2D one. Finally, the luminosity of a Schwarzschild black hole is calculated by using the geometric optics approximation.

  14. Testing general relativity with black-hole binary observations: results and prospects

    NASA Astrophysics Data System (ADS)

    Vallisneri, Michele

    2017-01-01

    The first two LIGO-Virgo detections of gravitational waves from binary black-hole inspirals offered the first opportunity to test gravitation in its strong-field, relativistic-motion, and radiative sector. The initial tests reported in PRL 116 (2016) probed consistency with the predictions of general relativity, to moderate precision. The space-based observatory LISA will observe black-hole binary signals with much larger SNRs, allowing for even more precise tests. Last, the detection of a binary black-hole stochastic background with pulsar-timing arrays will offer more constraints on the speed and polarizations of gravitational waves. I review these results and examine synergies across the gravitational-wave spectrum. I discuss the main challenges and opportunities from the viewpoint of data analysis, and outline prospects for making contact with current alternative theories of gravitation, in particular those motivated by models of dark energy.

  15. Selection bias in dynamically measured supermassive black hole samples: its consequences and the quest for the most fundamental relation

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Bernardi, Mariangela; Sheth, Ravi K.; Ferrarese, Laura; Graham, Alister W.; Savorgnan, Giulia; Allevato, Viola; Marconi, Alessandro; Läsker, Ronald; Lapi, Andrea

    2016-08-01

    We compare the set of local galaxies having dynamically measured black holes with a large, unbiased sample of galaxies extracted from the Sloan Digital Sky Survey. We confirm earlier work showing that the majority of black hole hosts have significantly higher velocity dispersions σ than local galaxies of similar stellar mass. We use Monte Carlo simulations to illustrate the effect on black hole scaling relations if this bias arises from the requirement that the black hole sphere of influence must be resolved to measure black hole masses with spatially resolved kinematics. We find that this selection effect artificially increases the normalization of the Mbh-σ relation by a factor of at least ˜3; the bias for the Mbh-Mstar relation is even larger. Our Monte Carlo simulations and analysis of the residuals from scaling relations both indicate that σ is more fundamental than Mstar or effective radius. In particular, the Mbh-Mstar relation is mostly a consequence of the Mbh-σ and σ-Mstar relations, and is heavily biased by up to a factor of 50 at small masses. This helps resolve the discrepancy between dynamically based black hole-galaxy scaling relations versus those of active galaxies. Our simulations also disfavour broad distributions of black hole masses at fixed σ. Correcting for this bias suggests that the calibration factor used to estimate black hole masses in active galaxies should be reduced to values of fvir ˜ 1. Black hole mass densities should also be proportionally smaller, perhaps implying significantly higher radiative efficiencies/black hole spins. Reducing black hole masses also reduces the gravitational wave signal expected from black hole mergers.

  16. The black hole-host galaxy relation for very low mass quasars

    NASA Astrophysics Data System (ADS)

    Sanghvi, J.; Kotilainen, J. K.; Falomo, R.; Decarli, R.; Karhunen, K.; Uslenghi, M.

    2014-12-01

    Recently, the relation between the masses of the black hole (MBH) and the host galaxy (Mhost) in quasars has been probed down to the parameter space of MBH ˜ 108 M⊙ and Mhost ˜ 1011 M⊙ at z < 0.5. In this study, we have investigated the MBH-Mhost log-linear relation for a sample of 37 quasars with low black hole masses (107 M⊙ < MBH < 108.3 M⊙) at 0.5 < z < 1.0. The black hole masses were derived using virial mass estimates from Sloan Digital Sky Survey (SDSS) optical spectra. For 25 quasars, we detected the presence of the host galaxy from deep near-infrared H-band imaging, whereas upper limits for the host galaxy luminosity (mass) were estimated for the 12 unresolved quasars. We combined our previous studies with the results from this work to create a sample of 89 quasars at z < 1.0 having a large range of black hole masses (107 M⊙ < MBH < 1010 M⊙) and host galaxy masses (1010 M⊙ < Mhost < 1013 M⊙). Most of the quasars at the low-mass end lie below the extrapolation of the local relation. This apparent break in the linearity of the entire sample is due to increasing fraction of disc-dominated host galaxies in the low-mass quasars. After correcting for the disc component, and considering only the bulge component, the bilinear regression for the entire quasar sample holds over 3.5 dex in both the black hole mass and the bulge mass, and is in very good agreement with the local relation. We advocate secular evolution of discs of galaxies being responsible for the relatively strong disc domination.

  17. Black gay men as sexual subjects: race, racialisation and the social relations of sex among Black gay men in Toronto.

    PubMed

    Husbands, Winston; Makoroka, Lydia; Walcott, Rinaldo; Adam, Barry D; George, Clemon; Remis, Robert S; Rourke, Sean B

    2013-01-01

    In this study of Black gay and bisexual men in Toronto, sexually active survey participants reported on their sexual behaviours with male partners of different ethnoracial backgrounds, and interview participants reflected on how their sexual relationships emerged in the context of race and interracial desire. Most survey participants reported sexual relationships with other Black men. Participants were more likely to be insertive with White and other ethnoracial men than with Black men. A significant number of participants who were receptive or versatile with Black partners switched to the insertive role when their sexual partners were not Black. Interview participants ascribed a sense of fulfilment to their sexual relationships with other Black men, but avoided relationships with White men or interpreted such relationships as either purely sexual and/or inflected by their racialised objectification. Others avoided sexual relationships with other Black men or preferred relationships with White men, sometimes in opposition to experiences of oppressive masculinity from some Black partners but mindful of the possibility of racialised encounters with their White partners. Study participants emerge as informed sexual subjects, self-conscious about their sexual relationships and variously inclined to negotiate or resist racialisation and oppression in the private and public spheres.

  18. Perspectives on Stress, Parenting, and Children’s Obesity-Related Behaviors in Black Families

    PubMed Central

    Parks, Elizabeth P.; Kazak, Anne; Kumanyika, Shiriki; Lewis, Lisa; Barg, Frances K.

    2016-01-01

    Objective In an effort to develop targets for childhood obesity interventions in non-Hispanic-Black (Black) families, this study examined parental perceptions of stress and identified potential links among parental stress and children’s eating patterns, physical activity, and screen-time. Method Thirty-three self-identified Black parents or grandparents of a child aged 3 to 7 years were recruited from a large, urban Black church to participate in semistructured interviews. Interviews were audio-recorded, transcribed, and analyzed using thematic analysis. Results Parents/grandparents described a pathway between how stress affected them personally and their child’s eating, structured (sports/dance) and unstructured (free-play) physical activity, and screen-time usage, as well as strategies to prevent this association. Five themes emerged: stress affects parent behaviors related to food and physical activity variably; try to be healthy even with stress; parent/grandparent stress eating and parenting; stress influences family cooking, food choices, and child free-play; and screen-time use to decrease parent stress. Negative parent/grandparent response to their personal stress adversely influenced food purchases and parenting related to child eating, free-play, and screen-time. Children of parents/grandparents who ate high-fat/high-sugar foods when stressed requested these foods. In addition to structured physical activity, cooking ahead and keeping food in the house were perceived to guard against the effects of stress except during parent cravings. Parent/child screen-time helped decrease parent stress. Conclusion Parents/grandparents responded variably to stress which affected the child eating environment, free-play, and screen-time. Family-based interventions to decrease obesity in Black children should consider how stress influences parents. Targeting parent cravings and coping strategies that utilize structure in eating and physical activity may be useful

  19. Perspectives on Stress, Parenting, and Children's Obesity-Related Behaviors in Black Families.

    PubMed

    Parks, Elizabeth P; Kazak, Anne; Kumanyika, Shiriki; Lewis, Lisa; Barg, Frances K

    2016-12-01

    Objective In an effort to develop targets for childhood obesity interventions in non-Hispanic-Black (Black) families, this study examined parental perceptions of stress and identified potential links among parental stress and children's eating patterns, physical activity, and screen-time. Method Thirty-three self-identified Black parents or grandparents of a child aged 3 to 7 years were recruited from a large, urban Black church to participate in semistructured interviews. Interviews were audio-recorded, transcribed, and analyzed using thematic analysis. Results Parents/grandparents described a pathway between how stress affected them personally and their child's eating, structured (sports/dance) and unstructured (free-play) physical activity, and screen-time usage, as well as strategies to prevent this association. Five themes emerged: stress affects parent behaviors related to food and physical activity variably; try to be healthy even with stress; parent/grandparent stress eating and parenting; stress influences family cooking, food choices, and child free-play; and screen-time use to decrease parent stress. Negative parent/grandparent response to their personal stress adversely influenced food purchases and parenting related to child eating, free-play, and screen-time. Children of parents/grandparents who ate high-fat/high-sugar foods when stressed requested these foods. In addition to structured physical activity, cooking ahead and keeping food in the house were perceived to guard against the effects of stress except during parent cravings. Parent/child screen-time helped decrease parent stress. Conclusion Parents/grandparents responded variably to stress which affected the child eating environment, free-play, and screen-time. Family-based interventions to decrease obesity in Black children should consider how stress influences parents. Targeting parent cravings and coping strategies that utilize structure in eating and physical activity may be useful

  20. Using Simulations of Black Holes to Study General Relativity and the Properties of Inner Accretion Flow

    NASA Astrophysics Data System (ADS)

    Hoormann, Janie Katherine

    2016-06-01

    While Albert Einstein's theory of General Relativity (GR) has been tested extensively in our solar system, it is just beginning to be tested in the strong gravitational fields that surround black holes. As a way to study the behavior of gravity in these extreme environments, I have used and added to a ray-tracing code that simulates the X-ray emission from the accretion disks surrounding black holes. In particular, the observational channels which can be simulated include the thermal and reflected spectra, polarization, and reverberation signatures. These calculations can be performed assuming GR as well as four alternative spacetimes. These results can be used to see if it is possible to determine if observations can test the No-Hair theorem of GR which states that stationary, astrophysical black holes are only described by their mass and spin. Although it proves difficult to distinguish between theories of gravity, it is possible to exclude a large portion of the possible deviations from GR using observations of rapidly spinning stellar mass black holes such as Cygnus X-1. The ray-tracing simulations can furthermore be used to study the inner regions of black hole accretion flows. I examined the dependence of X-ray reverberation observations on the ionization of the disk photosphere. My results show that X-ray reverberation and X-ray polarization provides a powerful tool to constrain the geometry of accretion disks which are too small to be imaged directly. The second part of my thesis describes the work on the balloon-borne X-Calibur hard X-ray polarimetry mission and on the space-borne PolSTAR polarimeter concept.

  1. Further Evidence for a Supermassive Black Hole Mass-Pitch Angle Relation

    NASA Astrophysics Data System (ADS)

    Berrier, Joel C.; Davis, Benjamin L.; Kennefick, Daniel; Kennefick, Julia D.; Seigar, Marc S.; Barrows, Robert Scott; Hartley, Matthew; Shields, Doug; Bentz, Misty C.; Lacy, Claud H. S.

    2013-06-01

    We present new and stronger evidence for a previously reported relationship between galactic spiral arm pitch angle P (a measure of the tightness of spiral structure) and the mass M BH of a disk galaxy's nuclear supermassive black hole (SMBH). We use an improved method to accurately measure the spiral arm pitch angle in disk galaxies to generate quantitative data on this morphological feature for 34 galaxies with directly measured black hole masses. We find a relation of log (M/M ⊙) = (8.21 ± 0.16) - (0.062 ± 0.009)P. This method is compared with other means of estimating black hole mass to determine its effectiveness and usefulness relative to other existing relations. We argue that such a relationship is predicted by leading theories of spiral structure in disk galaxies, including the density wave theory. We propose this relationship as a tool for estimating SMBH masses in disk galaxies. This tool is potentially superior when compared to other methods for this class of galaxy and has the advantage of being unambiguously measurable from imaging data alone.

  2. The Black Hole Mass - Pitch Angle Relation of Type I AGN In Spiral Galaxies

    NASA Astrophysics Data System (ADS)

    Schilling, Amanda; Jones, Logan; Hughes, John A.; Barrows, R. Scott; Kennefick, Julia D.

    2017-01-01

    A relationship between the mass of supermassive black holes, M, at the center of galaxies and the pitch angle, P, a measure of tightness of spiral arms, was recently reported by Berrier, et al. (2013 ApJ 769, 132) for late type galaxies. The relationship, established for a local sample, shows that spiral galaxies with tighter pitch angles host higher mass black holes. In this work, we explore the M-P relation for a sample of 50 low to moderate redshift (0.04relations to estimate black-hole mass. Pitch angles were measured using a 2DFFT technique (Davis, et al., 2012 ApJS 199, 33). We find that the M-P relation for the higher redshift, AGN sample differs from that of the local sample and discuss the possibility of AGN feedback by looking at a proposed Fundamental Plane for late-type galaxies - a correlation between bulge mass, disk mass, and spiral-arm pitch angle (Davis, et al. 2015, ApJ 802, L13).

  3. Probing the nonlinear structure of general relativity with black hole binaries

    NASA Astrophysics Data System (ADS)

    Arun, K. G.; Iyer, B. R.; Qusailah, M. S. S.; Sathyaprakash, B. S.

    2006-07-01

    Observations of the inspiral of massive binary black holes (BBH) in the Laser Interferometer Space Antenna (LISA) and stellar mass binary black holes in the European Gravitational Wave Observatory (EGO) offer an unique opportunity to test the nonlinear structure of general relativity. For a binary composed of two nonspinning black holes, the nonlinear general relativistic effects depend only on the masses of the constituents. In a recent paper, we explored the possibility of a test to determine all the post-Newtonian coefficients in the gravitational wave phasing. However, mutual covariances dilute the effectiveness of such a test. In this paper, we propose a more powerful test in which the various post-Newtonian coefficients in the gravitational wave phasing are systematically measured by treating three of them as independent parameters and demanding their mutual consistency. LISA (EGO) will observe BBH inspirals with a signal-to-noise ratio of more than 1000 (100) and thereby test the self-consistency of each of the nine post-Newtonian coefficients that have so-far been computed, by measuring the lower order coefficients to a relative accuracy of ˜10-5 (respectively, ˜10-4) and the higher order coefficients to a relative accuracy in the range 10-4-0.1 (respectively, 10-3-1).

  4. Further evidence for a supermassive black hole mass-pitch angle relation

    SciTech Connect

    Berrier, Joel C.; Kennefick, Daniel; Kennefick, Julia D.; Hartley, Matthew; Lacy, Claud H. S.; Davis, Benjamin L.; Barrows, Robert Scott; Shields, Doug; Seigar, Marc S.; Bentz, Misty C.

    2013-06-01

    We present new and stronger evidence for a previously reported relationship between galactic spiral arm pitch angle P (a measure of the tightness of spiral structure) and the mass M {sub BH} of a disk galaxy's nuclear supermassive black hole (SMBH). We use an improved method to accurately measure the spiral arm pitch angle in disk galaxies to generate quantitative data on this morphological feature for 34 galaxies with directly measured black hole masses. We find a relation of log (M/M {sub ☉}) = (8.21 ± 0.16) – (0.062 ± 0.009)P. This method is compared with other means of estimating black hole mass to determine its effectiveness and usefulness relative to other existing relations. We argue that such a relationship is predicted by leading theories of spiral structure in disk galaxies, including the density wave theory. We propose this relationship as a tool for estimating SMBH masses in disk galaxies. This tool is potentially superior when compared to other methods for this class of galaxy and has the advantage of being unambiguously measurable from imaging data alone.

  5. Orbit of the OJ287 black hole binary as determined from the General Relativity centenary flare

    NASA Astrophysics Data System (ADS)

    Valtonen, Mauri; Gopakumar, Achamveedu; Mikkola, Seppo; Zola, Staszek; Ciprini, Stefano; Matsumoto, Katsura; Sadakane, Kozo; Kidger, Mark; Gazeas, Kosmas; Nilsson, Kari; Berdyugin, Andrei; Piirola, Vilppu; Jermak, Helen; Baliyan, Kiran; Hudec, Rene; Reichart, Daniel

    2016-05-01

    OJ287 goes through large optical flares twice each 12 years. The times of these flares have been predicted successfully now 5 times using a black hole binary model. In this model a secondary black hole goes around a primary black hole, impacting the accretion disk of the latter twice per orbital period, creating a thermal flare. Together with 6 flares from the historical data base, the set of flare timings determines uniquely the 7 parameters of the model: the two masses, the primary spin, the major axis, eccentricity and the phase of the orbit, plus a time delay parameter that gives the extent of time between accretion disk impacts and the related optical flares. Based on observations by the OJ287-15/16 Collaboration, OJ287 went into the phase of rapid flux rise on November 25, on the centenary of Einstein’s General Relativity, and peaked on December 5. At that time OJ287 was the brightest in over 30 years in optical wavelengths. The flare was of low polarization, and did not extend beyond the optical/UV region of the spectrum. On top of the main flare there were a number of small flares; their excess brightness correlates well with the simultaneous X-ray data. With these properties the main flare qualifies as the marker of the orbit of the secondary going around the primary black hole. Since the orbit solution is strongly over-determined, its parameters are known very accurately, at better than one percent level for the masses and the spin. The next flare is predicted to peak on July 28, 2019.Detailed monitoring of this event should allow us to test, for the first time, the celebrated black hole no-hair theorem for a massive black hole at the 10% level. The present data is consistent with the theorem only at a 30% level. The main difficulty in observing OJ287 from Earth at our predicted epoch is its closeness to the sun. Therefore, it is desirable to monitor OJ287 from a space-based telescope not in the vicinity of Earth. Unfortunately, this unique opportunity

  6. Unequal burden of sleep-related obesity among black and white Americans

    PubMed Central

    Jean-Louis, Girardin; Youngstedt, Shawn; Grandner, Michael; Williams, Natasha J.; Sarpong, Daniel; Zizi, Ferdinand; Ogedegbe, Gbenga

    2015-01-01

    Background This study ascertained whether individuals of the black race/ethnicity are unequally burdened by sleep-related overweight/obesity. Methods Analysis was based on data obtained from Americans (ages, 18–85 years) in the National Health Interview Survey (1977–2009). Sleep duration was coded as either very short sleep (VSS) (≤5 hours), short sleep (SS) (5–6 hours), or long sleep (>8 hours), referenced to 7–8-hour sleepers. Overweight was defined as body mass index (BMI) ≥25.0 and ≤29.9 kg/m2 and obesity, BMI ≥30 kg/m2, referenced to normal weight (BMI = 18.5–24.9 kg/m2). Results Multivariate-adjusted regression analyses indicated that, among whites, VSS was associated with a 10% increased likelihood of being overweight and 51% increased likelihood of being obese, relative to 7–8-hour sleepers. Short sleep was associated with a 13% increased likelihood of being overweight and 45% increased likelihood of being obese. Long sleep was associated with 21% increased likelihood of being obese. Among blacks, VSS was associated with a 76% increased likelihood of being overweight and 81% increased likelihood of being obese. Short sleep was associated with a 16% increased likelihood of being overweight and 32% increased likelihood of being obese. As for the white stratum, long sleep was associated with a 25% increased likelihood of being obese. Conclusion Our investigation demonstrates strong linkages between inadequate sleep and overweight/ obesity among black and white Americans. Although it cannot be said that insufficient sleep causes overweight/obesity, individuals of the black race/ethnicity sleeping ≤5 hours may be unequally burdened by sleep-related overweight/obesity. PMID:26937487

  7. Relating follicly-challenged compact stars to bald black holes: A link between two no-hair properties

    NASA Astrophysics Data System (ADS)

    Yagi, Kent; Yunes, Nicolás

    2015-05-01

    Compact stars satisfy certain no-hair relations through which their multipole moments are given by their mass, spin and quadrupole moment. These relations are approximately independent of their equation of state, relating pressure to density. Such relations are similar to the black hole no-hair theorems, but these possess event horizons inside which information that led to their formation can hide. Compact stars do not possess horizons, so whether their no-hair relations are related to the black hole ones is unclear. We investigate how the two relations are related by studying relations among multipole moments for compact stars with anisotropic pressure as a toy model, which allows such stars to be more compact than those with isotropic pressure. We here show numerically that the compact star no-hair relations approach the black hole ones as the compactness approaches that of a black hole. We also prove analytically that the current dipole moment exactly reaches the black hole limit quadratically in compactness as strongly anisotropic stars approach the black hole limit. We moreover show that compact stars become progressively oblate in this limit, even if prolate at low compactness due to strong anisotropies.

  8. A massive binary black-hole system in OJ 287 and a test of general relativity.

    PubMed

    Valtonen, M J; Lehto, H J; Nilsson, K; Heidt, J; Takalo, L O; Sillanpää, A; Villforth, C; Kidger, M; Poyner, G; Pursimo, T; Zola, S; Wu, J-H; Zhou, X; Sadakane, K; Drozdz, M; Koziel, D; Marchev, D; Ogloza, W; Porowski, C; Siwak, M; Stachowski, G; Winiarski, M; Hentunen, V-P; Nissinen, M; Liakos, A; Dogru, S

    2008-04-17

    Tests of Einstein's general theory of relativity have mostly been carried out in weak gravitational fields where the space-time curvature effects are first-order deviations from Newton's theory. Binary pulsars provide a means of probing the strong gravitational field around a neutron star, but strong-field effects may be best tested in systems containing black holes. Here we report such a test in a close binary system of two candidate black holes in the quasar OJ 287. This quasar shows quasi-periodic optical outbursts at 12-year intervals, with two outburst peaks per interval. The latest outburst occurred in September 2007, within a day of the time predicted by the binary black-hole model and general relativity. The observations confirm the binary nature of the system and also provide evidence for the loss of orbital energy in agreement (within 10 per cent) with the emission of gravitational waves from the system. In the absence of gravitational wave emission the outburst would have happened 20 days later.

  9. The Black Pearl mine, Arizona - Wolframite veins and stockscheider pegmatite related to an albitic stock

    NASA Technical Reports Server (NTRS)

    Schmitz, Christopher; Burt, Donald M.

    1990-01-01

    Wolframite-bearing quartz veins flanked by greisen alteration occur at and near the Black Pearl mine, Yavapai County, Arizona. The veins are genetically related to a small albitite stock, and cut a series of Proterozoic metasedimentary and intrusive rocks. The largest vein, the only one mined, is located at the apex of the stock. Field relations imply that this stock is a late-stage differentiate of time 1.4-Ga anorogenic Lawler Peak batholith, which crops out about 3 km to the south. The albitites are of igneous origin and have suffered only minor deuteric alteration. A thin (1 to 2 m) pegmatite unit ('stockscheider') occurs at the contact of the Black Pearl Albitite stock with the country rocks. Directional indicators and other evidence suggest that the pegmatite was formed in the presence of a volatile-rich fluid phase close to the time of magma emplacement. The sudden change from coarse-grained microcline-rich pegmatite to fine-grained, albite-rich albitite suggests pressure quenching, possibly due to escape of fluids up the Black Pearl vein. Stockscheider-like textures typically occur near the apical contacts of productive plutons. The presence or absence of this texture is a useful guide in prospecting for lithophile metal deposits.

  10. Health-Related Stereotype Threat Predicts Health Services Delays Among Blacks

    PubMed Central

    Taylor, Dexter M.; Dampeer-Moore, Jodi; Van Allen, Katherine L.; Saunders, Darlene R.; Snowden, Cecelia B.; Johnson, Mark B.

    2013-01-01

    To our knowledge, no published research has developed an individual difference measure of health-related stereotype threat (HRST). We adapted existing measures of academic stereotype threat to the health domain on a sample of black college students (N = 280). The resulting health-related stereotype threat scale-24 (HRST-24) was assessed for internal consistency, construct and incremental validity, and whether it explains variance in self-reported delays among four preventive health behaviors—blood pressure and cholesterol assays, physical exams, and routine checkups. After adjusting for several control variables, the HRST-24’s (full scale α = 0.96) perceived black health inferiority (18 items; α = 0.96) and perceived physician racial bias (6 items; α = 0.85) sub-scales explained unique variance in delays among two of the four behaviors including a blood cholesterol check (p < .01) and routine checkup—albeit at marginal levels (p = .063) in the case of the latter. Overall, these data provide preliminary evidence of construct and incremental validity for the HRST-24 among blacks. Recommendations for administering the scale are provided and future directions for HRST research are discussed. PMID:24163710

  11. Establishing a relation between the mass and the spin of stellar-mass black holes.

    PubMed

    Banerjee, Indrani; Mukhopadhyay, Banibrata

    2013-08-09

    Stellar mass black holes (SMBHs), forming by the core collapse of very massive, rapidly rotating stars, are expected to exhibit a high density accretion disk around them developed from the spinning mantle of the collapsing star. A wide class of such disks, due to their high density and temperature, are effective emitters of neutrinos and hence called neutrino cooled disks. Tracking the physics relating the observed (neutrino) luminosity to the mass, spin of black holes (BHs) and the accretion rate (M) of such disks, here we establish a correlation between the spin and mass of SMBHs at their formation stage. Our work shows that spinning BHs are more massive than nonspinning BHs for a given M. However, slowly spinning BHs can turn out to be more massive than spinning BHs if M at their formation stage was higher compared to faster spinning BHs.

  12. The Supermassive Black Hole Mass - Pitch Angle Relation in Spiral Galaxies

    NASA Astrophysics Data System (ADS)

    Kennefick, Daniel; Berrier, J. C.; Kennefick, J. D.; Seigar, M.; Davis, B. L.; Barrows, R. S.; Shields, D.; Lacy, C. H.

    2013-01-01

    We present new and improved evidence for a strong correlation, with low scatter, between supermassive black hole mass and spiral arm pitch angle in disk galaxies. Such a correlation could be a useful tool for developing a SMBH mass function for both local and distant galaxies, because other host galaxy features which correlate with black hole mass either require expensive spectroscopy (as in the M-sigma relation) or work less well for spiral than for other galaxies because of the need to disentangle the bulge component from the disk and bar components (Bulge luminosity or Sersic index). A late-type SMBH mass function derived from pitch angle measurements could complement nicely early-type mass functions derived from these other measurements, especially because the late-type mass function has so far received less attention than the early-type mass function.

  13. Numerical Relativity Simulations of Black Holes Binaries, Neutron Star Binaries, and Neutron Star Oscillations

    NASA Astrophysics Data System (ADS)

    Rosofsky, Shawn; Gold, Roman; Chirenti, Cecilia; Miller, Cole

    2017-01-01

    We present the results of numerical relativity simulations, using the Einstein Toolkit, of black hole binaries, neutron star binaries, and neutron star oscillations. The black hole binary simulations represent the source of LIGO's first gravitational wave detection, GW150914. We compare the gravitational wave output of this simulation with the LIGO data LIGO on GW150914. The neutron star binaries we simulated have different mass ratios and equations of state. These simulations were compared with each other to illustrate the effect of different mass ratios and equations of state on binary evolution and gravitational wave emission. To perform the neutron star oscillation simulations, we applied pressure and density perturbations to the star using specific eigenmodes. These evolutions of the stars were then compared to the expected oscillation frequencies of those excited eigemodes and contrasted with simulations of unperturbed neutron stars.

  14. Binary Dynamics, Black Holes, and Inflationary Perturbations: Applications in General Relativity and Field Theory

    NASA Astrophysics Data System (ADS)

    Gilmore, James Brian

    2010-12-01

    General Relativity is the standard framework by which all gravitational systems are analyzed in modern research, and it provides the theme for all the investigations in this thesis. Beyond this common platform, very different gravitating problems are examined here, and several analytical approaches are used to investigate these systems. Effective field theory, a methodological approach prominent in quantum field theory, plays an important role in the analysis of two of the problems in this thesis. In the first instance, an effective field theory for bound gravitational states is used to compute the interaction Lagrangian of a binary system at the second post-Newtonian order. A metric parametrization based on a temporal Kaluza-Klein decomposition is also used. In this effective field theory calculation, the post-Newtonian results for the equations of motion are elegantly reproduced. In the next problem considered, effective field theory is used to investigate the thermodynamics of compactified charged black holes. The relevant thermodynamic quantities are all computed to second order in the perturbation parameter and finite size effects are incorporated through higher order worldline operators. Complete agreement is found with an exact extremal black hole solution constructed with traditional General Relativistic methods. The results indicate that the addition of charge to a compactified black hole may delay the phase transition to a black string. Finally, the third problem examined here concerns the evolution of perturbations at the end of early universe inflation. General Relativity enters this problem through cosmological perturbation theory. It is shown that the coherent oscillations in the inflaton break down at the comoving post-inflationary horizon size, about 14 e-folds after the end of inflation. This is many e-folds before any known constraints, leading to possible implications for the matching problem of inflation, and the generation of stochastic

  15. UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

    SciTech Connect

    Scott, Nicholas; Graham, Alister W.

    2013-02-15

    We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, M {sub NC}, correlates most tightly with the host galaxy's velocity dispersion: log M {sub NC} = (2.11 {+-} 0.31)log ({sigma}/54) + (6.63 {+-} 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, M {sub NC}{proportional_to}M {sup 0.55{+-}0.15} {sub Gal,dyn}; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.

  16. THE M {sub BH}-L {sub SPHEROID} RELATION AT HIGH AND LOW MASSES, THE QUADRATIC GROWTH OF BLACK HOLES, AND INTERMEDIATE-MASS BLACK HOLE CANDIDATES

    SciTech Connect

    Graham, Alister W.; Scott, Nicholas

    2013-02-20

    From a sample of 72 galaxies with reliable supermassive black hole masses M {sub bh}, we derive the M {sub bh}-(host spheroid luminosity, L) relation for (1) the subsample of 24 core-Sersic galaxies with partially depleted cores, and (2) the remaining subsample of 48 Sersic galaxies. Using K{sub s} -band Two Micron All Sky Survey data, we find the near-linear relation M {sub bh}{proportional_to}L {sup 1.10{+-}0.20} {sub K{sub s}} for the core-Sersic spheroids thought to be built in additive dry merger events, while we find the relation M {sub bh}{proportional_to}L {sup 2.73{+-}0.55}{sub K{sub s}} for the Sersic spheroids built from gas-rich processes. After converting literature B-band disk galaxy magnitudes into inclination- and dust-corrected bulge magnitudes, via a useful new equation presented herein, we obtain a similar result. Unlike with the M {sub bh}-(velocity dispersion) diagram, which is also updated here using the same galaxy sample, it remains unknown whether barred and non-barred Sersic galaxies are offset from each other in the M {sub bh}-L diagram. While black hole feedback has typically been invoked to explain what was previously thought to be a nearly constant M {sub bh}/M {sub Spheroid} mass ratio of {approx}0.2%, we advocate that the near-linear M {sub bh}-L and M {sub bh}-M {sub Spheroid} relations observed at high masses may have instead arisen largely from the additive dry merging of galaxies. We argue that feedback results in a dramatically different scaling relation, such that black hole mass scales roughly quadratically with the spheroid mass in Sersic galaxies. We therefore introduce a revised cold-gas 'quasar' mode feeding equation for semi-analytical models to reflect what we dub the quadratic growth of black holes in Sersic galaxies built amidst gas-rich processes. Finally, we use our new Sersic M {sub bh}-L equations to predict the masses of candidate intermediate mass black holes in almost 50 low-luminosity spheroids containing

  17. HIV-related behaviors among black students attending Historically Black Colleges and Universities (HBCUs) versus white students attending a traditionally white institution (TWI).

    PubMed

    Hou, Su-I

    2009-08-01

    Recent data indicated the unexpected movement of the HIV epidemic in the Southeastern US and the transmission among college students especially in black campuses. The current study is the first one attempted to assess and compare HIV-related behaviors among black students attending Historically Black Colleges and Universities (HBCUs) and white students attending a traditionally white institution (TWI). Black students were recruited from HBCUs (n=222) and white students from a TWI (n=335) via online surveys. The majority of students in both samples were between 18 and 24 years old (mean = 20.65) and self-identified as heterosexual oriented (91%), although the HBCU sample revealed slightly higher proportion of females (81.1% vs. 72.5%). Data indicated different behavioral patterns. Although, both groups reported similar prevalence of oral and anal sex; after adjusting for age and gender, HBCU blacks were more likely to have had vaginal sex (OR = 1.7) and at younger age (16.3 vs. 17.5 years), more likely to have had Sexually Transmitted Infections (OR = 4.4), have been or gotten someone pregnant (OR = 3.6). They were, however, less likely to use alcohol before sex of any type, and more likely to have been tested for HIV (OR = 8.4), ask partner's status (OR = 3.8) or being asked of status (OR = 2.9). Comparing with TWI whites, HBCU blacks also perceived higher risk of HIV infection, higher peer norms toward vaginal and anal sex. The findings showed HBCU students taking more protective behaviors in some aspects while practicing riskier behaviors in others. Results have implications on developing tailored HIV behavioral interventions.

  18. Identification of mitochondrial DNA substitutions related to meat quality in Japanese Black cattle.

    PubMed

    Mannen, H; Morimoto, M L; Oyamat, K; Mukai, F; Tsuji, S

    2003-01-01

    Complete sequences of mitochondrial (mt) genomes of eight Japanese Black cattle were determined to investigate the relationships between mt deoxyribonucleic acid (DNA) displacement loop (D-loop) types and other mtDNA regions and to identify the variation in the coding region that may influence the economic traits. The survey of mitochondrial sequences in the encoding region revealed 14 substitutions including six antonymous substitutions and one in 16S ribosomal ribonucleic acid (rRNA). Three methods of polymorphic DNA analyses (polymerase chain reaction [PCR]-restriction fragment length polymorphism [RFLP], mismatch PCR-RFLP, PCR-single-strand conformation polymorphism [SSCP]) were performed on these seven candidate substitutions (base pair [bp] 2,232, 12,158, 12,908, 13,310, 14,122, 14,140, and 14,565) for 202 Japanese Black cattle. The substitution of bp 13,310 was observed in all samples, but not in the reference sequence, indicating that this is a minor substitution or a sequencing mistake in the reference sequence. The substitutions at bp 14,122, 14,140, and 14,565 were observed in only a few samples, suggesting that these were also minor substitutions. The substitutions at bp 2,232 (16S rRNA), 12,158, and 12,908 (reduced nicotinamide adenine dinucleotide-ubiquinone oxidoreductase chain-5) were closely related to mitochondrial D-loop types that have previously been related to differences in the carcass traits of Japanese Black cattle. Evaluation of the effects on six carcass traits with mixed model procedures suggests that the bp 2,232 substitution affects longissimus muscle area and beef marbling score. The substitution at bp 2,232 is a strong candidate for the mitochondrial effect on meat quality.

  19. THE RELATION BETWEEN BLACK HOLE MASS AND HOST SPHEROID STELLAR MASS OUT TO z {approx} 2

    SciTech Connect

    Bennert, Vardha N.; Auger, Matthew W.; Treu, Tommaso; Woo, Jong-Hak; Malkan, Matthew A. E-mail: tt@physics.ucsb.edu E-mail: woo@astro.snu.ac.kr

    2011-12-01

    We combine Hubble Space Telescope images from the Great Observatories Origins Deep Survey with archival Very Large Telescope and Keck spectra of a sample of 11 X-ray-selected broad-line active galactic nuclei in the redshift range 1 < z < 2 to study the black-hole-mass-stellar-mass relation out to a look-back time of 10 Gyr. Stellar masses of the spheroidal component (M{sub sph,*}) are derived from multi-filter surface photometry. Black hole masses (M{sub BH}) are estimated from the width of the broad Mg II emission line and the 3000 A nuclear luminosity. Comparing with a uniformly measured local sample and taking into account selection effects, we find evolution in the form M{sub BH}/M{sub sph,*}{proportional_to}(1 + z){sup 1.96{+-}}0{sup .55}, in agreement with our earlier studies based on spheroid luminosity. However, this result is more accurate because it does not require a correction for luminosity evolution and therefore avoids the related and dominant systematic uncertainty. We also measure total stellar masses (M{sub host,*}). Combining our sample with data from the literature, we find M{sub BH}/M{sub host,*}{proportional_to}(1 + z){sup 1.15{+-}0.15}, consistent with the hypothesis that black holes (in the range M{sub BH} {approx} 10{sup 8-9} M{sub Sun }) pre-date the formation of their host galaxies. Roughly, one-third of our objects reside in spiral galaxies; none of the host galaxies reveal signs of interaction or major merger activity. Combined with the slower evolution in host stellar masses compared to spheroid stellar masses, our results indicate that secular evolution or minor mergers play a non-negligible role in growing both BHs and spheroids.

  20. Surrogate models of gravitational waveforms from numerical relativity simulations of precessing binary black hole mergers

    NASA Astrophysics Data System (ADS)

    Blackman, Jonathan; Field, Scott; Galley, Chad; Hemberger, Daniel; Scheel, Mark; Schmidt, Patricia; Smith, Rory

    2017-01-01

    Extracting astrophysical parameters and testing general relativity from gravitational wave observations of binary black hole mergers requires high-fidelity signal predictions. The effective-one-body model and phenomenological waveform models have been shown to work well for a subset of the possible parameter space. They could be insufficiently accurate for estimating the parameters of a loud gravitational wave detection in other regions of the parameter space. Numerical relativity (NR) surrogate models attempt to rapidly and accurately interpolate the waveforms from a set of NR simulations over a subset of parameter space. Using the Spectral Einstein Code (SpEC), we have built NR surrogate models for precessing binaries with a restricted spin direction on the smaller black hole, and are actively working on extending this to the full 7d parameter space of non-eccentric binaries. The NR surrogate models typically perform an order of magnitude better than other waveform models when compared to NR waveforms which were not included in the surrogate training set, and can be used in gravitational wave parameter estimation.

  1. Updating the Trainability Tests Literature on Black-White Subgroup Differences and Reconsidering Criterion-Related Validity

    ERIC Educational Resources Information Center

    Roth, Philip L.; Buster, Maury A.; Bobko, Philip

    2011-01-01

    A number of applied psychologists have suggested that trainability test Black-White ethnic group differences are low or relatively low (e.g., Siegel & Bergman, 1975), though data are scarce. Likewise, there are relatively few estimates of criterion-related validity for trainability tests predicting job performance (cf. Robertson & Downs,…

  2. Figurative Language of Disadvantaged Blacks as Related to Poverty, Music, Poetry, Language and Reading.

    ERIC Educational Resources Information Center

    Allen, Walter R.

    The unjustified assumption that black children have limited verbal or articulation skills stems from the fact that blacks use figurative, nonliteral, and nonstandard language in the classroom. The language that most disadvantaged blacks learn at home and bring to the classroom is a restricted form born out of poverty and limited exposure to good…

  3. Perspectives on Stress, Parenting, and Children's Obesity-Related Behaviors in Black Families

    ERIC Educational Resources Information Center

    Parks, Elizabeth P.; Kazak, Anne; Kumanyika, Shiriki; Lewis, Lisa; Barg, Frances K.

    2016-01-01

    Objective: In an effort to develop targets for childhood obesity interventions in non-Hispanic-Black (Black) families, this study examined parental perceptions of stress and identified potential links among parental stress and children's eating patterns, physical activity, and screen-time. Method: Thirty-three self-identified Black parents or…

  4. 20 CFR 422.512 - Applications and related forms used in the black lung benefits program.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... black lung benefits program. 422.512 Section 422.512 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... black lung benefits program. (a) Application forms. The following forms are prescribed for use in... Act of 1969, as amended by the Black Lung Benefits Act of 1972: SSA-46—Application for Benefits...

  5. 20 CFR 422.512 - Applications and related forms used in the black lung benefits program.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... black lung benefits program. 422.512 Section 422.512 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... black lung benefits program. (a) Application forms. The following forms are prescribed for use in... Act of 1969, as amended by the Black Lung Benefits Act of 1972: SSA-46—Application for Benefits...

  6. 20 CFR 422.512 - Applications and related forms used in the black lung benefits program.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... black lung benefits program. 422.512 Section 422.512 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... black lung benefits program. (a) Application forms. The following forms are prescribed for use in... Act of 1969, as amended by the Black Lung Benefits Act of 1972: SSA-46—Application for Benefits...

  7. 20 CFR 422.512 - Applications and related forms used in the black lung benefits program.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... black lung benefits program. 422.512 Section 422.512 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... black lung benefits program. (a) Application forms. The following forms are prescribed for use in... Act of 1969, as amended by the Black Lung Benefits Act of 1972: SSA-46—Application for Benefits...

  8. 20 CFR 422.512 - Applications and related forms used in the black lung benefits program.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... black lung benefits program. 422.512 Section 422.512 Employees' Benefits SOCIAL SECURITY ADMINISTRATION... black lung benefits program. (a) Application forms. The following forms are prescribed for use in... Act of 1969, as amended by the Black Lung Benefits Act of 1972: SSA-46—Application for Benefits...

  9. Bulk supertranslation memories: A concept reshaping the vacua and black holes of general relativity

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey

    2016-07-01

    The memory effect is a prediction of general relativity on the same footing as the existence of gravitational waves. The memory effect is understood at future null infinity as a transition induced by null radiation from a Poincaré vacuum to another vacuum. Those are related by a supertranslation, which is a fundamental symmetry of asymptotically flat spacetimes. In this paper, I argue that finite supertranslation diffeomorphisms should be extended into the bulk spacetime consistently with canonical charge conservation. It then leads to fascinating geometrical features of gravitational Poincaré vacua. I then argue that in the process of black hole merger or gravitational collapse, dramatic but computable memory effects occur. They lead to a final stationary metric which qualitatively deviates from the Schwarzschild metric.

  10. Stellar Populations across the Black Hole Mass-Velocity Dispersion Relation

    NASA Astrophysics Data System (ADS)

    Martín-Navarro, Ignacio; Brodie, Jean P.; van den Bosch, Remco C. E.; Romanowsky, Aaron J.; Forbes, Duncan A.

    2016-11-01

    Coevolution between supermassive black holes (BH) and their host galaxies is universally adopted in models for galaxy formation. In the absence of feedback from active galactic nuclei (AGNs), simulated massive galaxies keep forming stars in the local universe. From an observational point of view, however, such coevolution remains unclear. We present a stellar population analysis of galaxies with direct BH mass measurements and the BH mass-σ relation as a working framework. We find that over-massive BH galaxies, i.e., galaxies lying above the best-fitting BH mass-σ line, tend to be older and more α-element-enhanced than under-massive BH galaxies. The scatter in the BH mass-σ-[α/Fe] plane is significantly lower than that in the standard BH mass-σ relation. We interpret this trend as an imprint of AGN feedback on the star formation histories of massive galaxies.

  11. Pathways to HIV-Related Behavior Among Heterosexual, Rural Black Men: A Person-Centered Analysis.

    PubMed

    Kogan, Steven M; Cho, Junhan; Barnum, Stacey; Barton, Allen; Hicks, Megan R; Brown, Geoffrey L

    2015-12-23

    We investigated the psychosocial mechanisms linking personal and contextual risk factors to HIV-related behavior among 498 rural Black men. We characterized HIV-related behavior in terms of profile groups and hypothesized that contextual and personal risk factors (childhood adversity, community disadvantage, incarceration, and racial discrimination) would predict HIV-related behavior indirectly via two psychosocial mechanisms: impulsivity and negative relational schemas. Study results documented three HIV-related behavior profile groups. The Safer group reported low levels of risky behavior. The Risk-Taking group reported inconsistent condom use and elevated substance use. The Multiple Partners group reported the highest numbers of partners and relatively consistent condom use. Risk factors predicted profile groups directly and indirectly through psychosocial mechanisms. Impulsivity mediated the association between community disadvantage and membership in the risk-taking group. Negative relational schemas mediated the associations of childhood experiences and community disadvantage with membership in the multiple partners group. Specificity in pathways suggests the need for targeted interventions based on multidimensional characterizations of risk behavior.

  12. Fast and Accurate Prediction of Numerical Relativity Waveforms from Binary Black Hole Coalescences Using Surrogate Models.

    PubMed

    Blackman, Jonathan; Field, Scott E; Galley, Chad R; Szilágyi, Béla; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A

    2015-09-18

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. Using reduced order modeling techniques, we construct an accurate surrogate model, which is evaluated in a millisecond to a second, for numerical relativity (NR) waveforms from nonspinning binary black hole coalescences with mass ratios in [1, 10] and durations corresponding to about 15 orbits before merger. We assess the model's uncertainty and show that our modeling strategy predicts NR waveforms not used for the surrogate's training with errors nearly as small as the numerical error of the NR code. Our model includes all spherical-harmonic _{-2}Y_{ℓm} waveform modes resolved by the NR code up to ℓ=8. We compare our surrogate model to effective one body waveforms from 50M_{⊙} to 300M_{⊙} for advanced LIGO detectors and find that the surrogate is always more faithful (by at least an order of magnitude in most cases).

  13. Tests of general relativity from gravitational wave observations of binary black holes

    NASA Astrophysics Data System (ADS)

    Del Pozzo, Walter

    2017-01-01

    Gravitational waves emitted during the coalescence of compact binary systems carry a wealth of information about the merging objects, the remnant object as well as their interaction with space-time. The description of the dynamics of such systems is based on solutions of the theory of general relativity. For any given physical configuration of masses, spins and orbital motion, general relativity predicts the dynamical evolution of the binary system as well as the corresponding gravitational wave signal. During the coalescence of extremely compact objects such as binary black holes, the typical curvature and velocity at play are such that, from the observation of the gravitational wave signal, we can access the most extreme dynamical regimes of gravity. In such conditions, we can test our understanding of gravity by looking for potential departures between the solutions of general relativity and the actual dynamics of space-time. The LIGO observations GW150914 and GW151226 provided wonderful testing grounds for general relativity in the, up to now unaccessible, strong-field dynamical regime of gravity. During my talk, I will review and discuss several of the tests that have been devised to detect violations of the predictions of general relativity from the observation of gravitational waves from coalescing binary systems. The discussion will be based on the results of the analysis of GW150914 and GW151226. Finally, I will conclude by discussing some of the future prospects of extending the current state-of-the-art methodologies to further aspects of general relativity.

  14. The Influence of Racism-Related Stress on the Academic Motivation of Black and Latino/a Students

    ERIC Educational Resources Information Center

    Reynolds, Amy L.; Sneva, Jacob N.; Beehler, Gregory P.

    2010-01-01

    This study examined the effects of racism-related stress on the academic and psychological factors affecting the success of 151 Black and Latino/a college students enrolled at several predominantly White universities in the northeastern United States. Institutional racism-related stress was negatively correlated with extrinsic motivation but…

  15. Monitoring contaminant exposure: Relative concentrations of organochlorines in three tissues of American black ducks

    USGS Publications Warehouse

    Hall, R.J.; Haseltine, S.D.; Geissler, P.H.

    1989-01-01

    Comparison of organochlorine residues in wildlife must often be made to regulatory standards or to values of known biological significance; this is difficult when dissimilar tissues are analyzed and results are expressed on different bases. To relate levels in the different tissues used for regulatory and monitoring purposes and for biological assessments, we exposed American black ducks to mixtures of three organochlorines. Differences in residue burdens among tissues were not statistically significant when levels were expressed on a lipid weight basis. Levels of heptachlor and Aroclor 1254 in one tissue can be accurately predicted from those in another; such predictions for endrin are less reliable. Lipid weight based residue concentrations in wings may be used to predict whether levels in fat exceed residue standards set for human health or approach those associated with effects on populations of species sampled.

  16. Modified Dispersion Relations: from Black-Hole Entropy to the Cosmological Constant

    NASA Astrophysics Data System (ADS)

    Garattini, Remo

    2012-07-01

    Quantum Field Theory is plagued by divergences in the attempt to calculate physical quantities. Standard techniques of regularization and renormalization are used to keep under control such a problem. In this paper we would like to use a different scheme based on Modified Dispersion Relations (MDR) to remove infinities appearing in one loop approximation in contrast to what happens in conventional approaches. In particular, we apply the MDR regularization to the computation of the entropy of a Schwarzschild black hole from one side and the Zero Point Energy (ZPE) of the graviton from the other side. The graviton ZPE is connected to the cosmological constant by means of of the Wheeler-DeWitt equation.

  17. Black bear habitat use in relation to food availability in the Interior Highlands of Arkansas

    USGS Publications Warehouse

    Clark, Joseph D.; Clapp, Daniel L.; Smith, Kimberly G.; Ederington, Belinda

    1994-01-01

    A black bear (Ursus americanus) food value index (FVI) was developed and calculated for forest cover type classifications on Ozark Mountain (White Rock) and Ouachita Mountain (Dry Creek) study areas in western Arkansas. FVIs are estimates of bear food production capabilities of the major forest cover types and were calculated using percent cover, mean fruit production scorings, and the dietary percentage of each major plant food species as variables. Goodness-of-fit analyses were used to determine use of forest cover types by 23 radio-collared female bears. Habitat selection by forest cover type was not detected on White Rock but was detected on Dry Creek. Use of habitats on Dry Creek appeared to be related to food production with the exception of regeneration areas, which were used less than expected but had a high FVI ranking. In general, pine cover types had low FVI rankings and were used less than expected by bears. Forest management implications are discussed. 

  18. Cognitive-motivational influences on the task-related help-seeking behavior of black children.

    PubMed

    Nelson-Le Gall, S; Jones, E

    1990-04-01

    The present study examined the relation between children's mastery motivation, self-assessment of performance, and task-related help-seeking behavior during task performance. Average-achieving black American children, varying in mastery motivation as measured by subscales of the Harter's Intrinsic-Extrinsic Orientation in the Classroom Scale, performed a multitrial verbal task and were given the opportunity to seek help on each trial after making a tentative response and assessing their performance by rating their confidence in the correctness of the response. A response-contingent payoff system was implemented to encourage children to restrict their help seeking to those instances in which they perceived that they could not make a correct response without assistance. As predicted, children's self-assessments of performance, regardless of their accuracy, appeared to influence help seeking more than the actual performance outcomes. Neither children's self-assessments of performance nor their overall rate of help seeking varied with level of measured mastery motivation. However, the type of help sought varied as expected with mastery motivation. Children characterized by high intrinsic orientations toward independent mastery in academic achievement contexts sought indirect help (i.e., hints) more often than they sought direct help (i.e., answers), whereas children characterized by low intrinsic orientations toward independent mastery showed no preference. These differences in motivational orientation influenced requests for help only when children perceived their initial solutions to be incorrect. These findings are discussed in the context of the analyses of help seeking as an instrumental learning and achievement strategy. The implications of the findings for analyses of black children's achievement styles are highlighted.

  19. Examining the Association Between Body Mass Index and Weight Related Quality of Life in Black and White Women

    PubMed Central

    Ard, Jamy D.; Beasley, T. Mark; Fernandez, Jose R.; Howard, Virginia J.; Kolotkin, Ronnete L.; Crosby, Ross D.; Affuso, Olivia

    2017-01-01

    Obesity not only increases risk for morbidity/mortality, but also impacts the quality of life of obese individuals. In the United States, black women have the highest prevalence of obesity of any other group with approximately 80% of black women over age 20 having a body mass index (BMI) ≥25 kg/m2. We aimed to examine the association between BMI and quality of life in this high risk population compared to this association in white women, using the Impact of Weight on Quality of Life (IWQOL)-Lite questionnaire. Data from 172 black women (mean BMI= 35.7; age=40.5) and 171 white women (mean BMI= 35.5; age=40.4) were collected between 2000 and 2010 analyzed in 2010. The mean IWQOL-Lite total score was 81.6 for black women compared to 66.9 for white women, a statistically significant difference. Hierarchical linear regression models revealed a significant BMI-by-race interaction indicating that the relationship between BMI and IWQOL-Lite score was moderated by race. Our findings suggest notable differences in weight-related quality of life in black and white women. At similar BMIs, black women consistently reported better quality of life than white women on all IWQOL-Lite subscales. The greatest difference in IWQOL-Lite scores between black and white women was seen in the self-esteem subscale. Additional research is needed to understand how to incorporate the weight perspectives of black women into weight management messages and interventions.

  20. Disk Assembly and the M BH-σ e Relation of Supermassive Black Holes

    NASA Astrophysics Data System (ADS)

    Debattista, Victor P.; Kazantzidis, Stelios; van den Bosch, Frank C.

    2013-03-01

    Recent Hubble Space Telescope observations have revealed that a majority of active galactic nuclei (AGNs) at z ~ 1-3 are resident in isolated disk galaxies, contrary to the usual expectation that AGNs are triggered by mergers. Here we develop a new test of the cosmic evolution of supermassive black holes (SMBHs) in disk galaxies by considering the local population of SMBHs. We show that substantial SMBH growth in spiral galaxies is required as disks assemble. SMBHs exhibit a tight relation between their mass and the velocity dispersion of the spheroid within which they reside, the M •-σ e relation. In disk galaxies the bulge is the spheroid of interest. We explore the evolution of the M •-σ e relation when bulges form together with SMBHs on the M •-σ e relation and then slowly re-form a disk around them. The formation of the disk compresses the bulge, raising its σ e . We present evidence for such compression in the form of larger velocity dispersion of classical bulges compared with elliptical galaxies at the same mass. This compression leads to an offset in the M •-σ e relation if it is not accompanied by an increased M •. We quantify the expected offset based on photometric data and show that, on average, SMBHs must grow by ~50%-65% just to remain on the M •-σ e relation. We find no significant offset in the M •-σ e relations of classical bulges and of ellipticals, implying that SMBHs have been growing along with disks. Our simulations demonstrate that SMBH growth is necessary for the local population of disk galaxies to have remained on the M •-σ e relation.

  1. Reproduction of black-crowned night-herons related to predation and contaminants

    USGS Publications Warehouse

    Blus, L.J.; Rattner, B.A.; Melancon, M.J.; Henny, C.J.

    1996-01-01

    Reproductive characteristics were studied at five colonies of Black-crowned Night-Herons (Nycticorax nycticorax) in south central Washington (4) and north central Oregon (1) in 1991. Predation (primarily avian) was a major factor that adversely affected reproductive success in three colonies and was relatively unimportant in two colonies. The mean number of young surviving to 14 days of age in each colony ranged from 0.47 to 1.94 per nesting female (includes recycling efforts). Unadjusted nest success at each I colony ranged from 31 to 84% (including recycling efforts). Clutch size and incidence of recycling also varied markedly by colony. Residues of DDE, total PCBs, and related compounds were relatively low in most eggs, and mean eggshell thinning by colony ranged from 7 to 11 %. Cytochrome P-450 enzyme (EROD, PROD, and BROD) induction in livers of pipped embryos by colony ranged from low to average in comparison with other colonies throughout the U.S. Residues of dioxins (TCDD) and furans (TCDF) in eggs were generally low and apparently had little influence on reproductive success at any of the colonies.

  2. HIV-related stigma among African, Caribbean, and Black youth in Windsor, Ontario.

    PubMed

    Mihan, Robert; Kerr, Jelani; Maticka-Tyndale, Eleanor

    2016-01-01

    HIV-related stigma has been shown to undermine prevention, care, treatment, and the well-being of people living with HIV. A disproportion burden of HIV infection, as well as elevated levels of HIV-related stigma, is evidenced in sub-Saharan African (SSA) and African-diasporic populations. This study explores factors that influence HIV-related stigma among 16- to 25-year-old youth residing in a Canadian city who identify as African, Caribbean, or Black. Stigma, as rooted in cultural norms and beliefs and related social institutions, combined with insights from research on stigma in SSA and African-diasporic populations, guided the development of a path analytic structural equation model predicting levels of HIV-related stigmatizing attitudes. The model was tested using survey responses of 510 youth to estimate the direct and indirect influences of ethno-religious identity, religious service attendance, time in Canada, HIV/AIDS knowledge, HIV-testing history, sexual health service contact, and gender on HIV-related stigma. Statistically significant negative associations were found between levels of stigma and knowledge and HIV-testing history. Ethno-religious identity and gender had both direct and indirect effects on stigma. African-Muslim participants had higher levels of stigma, lower knowledge, and were less likely to have been tested for HIV infection than other ethno-religious groups. Male participants had higher levels of stigma and lower knowledge than women. Time in Canada had only indirect effects on stigma, with participants in Canada for longer periods having higher knowledge and less likely to have been tested than more recent arrivals. While the strength of the effect of knowledge on stigmatizing attitudes in this research is consistent with other research on stigma and evaluations of stigma-reduction programs, the path analytic results provide additional information about how knowledge and HIV-testing function as mediators of non

  3. Black Lives, White Lives. Three Decades of Race Relations in America.

    ERIC Educational Resources Information Center

    Blauner, Bob

    This book explores the racial experience and consciousness of black and white Americans within the context of their lives over the course of 20 years. The subjects of this book, 16 blacks and 12 whites, were interviewed in 1968, again in 1978-79, and for a third time in 1986. They speak in their own words about how their lives unfolded, how their…

  4. Dark-matter haloes and the M-σ relation for supermassive black holes

    NASA Astrophysics Data System (ADS)

    Larkin, Adam C.; McLaughlin, Dean E.

    2016-10-01

    We develop models of two-component spherical galaxies to establish scaling relations linking the properties of spheroids at z = 0 (total stellar masses, effective radii Re and velocity dispersions within Re) to the properties of their dark-matter haloes at both z = 0 and higher redshifts. Our main motivation is the widely accepted idea that the accretion-driven growth of supermassive black holes (SMBHs) in protogalaxies is limited by quasar-mode feedback and gas blow-out. The SMBH masses, MBH, should then be connected to the dark-matter potential wells at the redshift zqso of the blow-out. We specifically consider the example of a power-law dependence on the maximum circular speed in a protogalactic dark-matter halo: M_{BH}∝ V^4_{d,pk}, as could be expected if quasar-mode feedback were momentum-driven. For haloes with a given Vd,pk at a given zqso ≥ 0, our model scaling relations give a typical stellar velocity dispersion σap(Re) at z = 0. Thus, they transform a theoretical MBH-Vd,pk relation into a prediction for an observable MBH-σap(Re) relation. We find the latter to be distinctly non-linear in log-log space. Its shape depends on the generic redshift evolution of haloes in a Λ cold dark matter cosmology and the systematic variation of stellar-to-dark matter mass fraction at z = 0, in addition to any assumptions about the physics underlying the MBH-Vd,pk relation. Despite some clear limitations of the form we use for MBH versus Vd,pk, and even though we do not include any SMBH growth through dry mergers at low redshift, our results for MBH-σap(Re) compare well to data for local early types if we take zqso ˜ 2-4.

  5. The relative stability of black hole threshold solutions in gravitational collapse

    NASA Astrophysics Data System (ADS)

    Brasoveanu, Theodor; Pretorius, Frans

    2012-03-01

    We present numerical studies of the relative stability of critical solutions in problems of gravitational collapse. These strong-field solutions to Einstein equations, initially discovered by M. Choptuik, arise at the threshold of black hole formation. We study the evolution of systems with multiple matter sources (such as scalar or Yang-Mills fields) that exhibit the same type of threshold solution when studied individually and only interact with each other gravitationally. Given the unstable nature of critical solutions, the central question that we address is how does matter of one type behave in the presence of a critical solution of another type of matter. Preliminary results, using adaptive grid techniques to solve Einstein equations coupled to matter, indicate that the near-critical solution of the combined system seems to switch from one type of threshold to another, as the critical point is approached in parameter space. The overall dynamics (exhibiting time-periodicity or self-similarity) depends on the relative amounts of energy present in the system and on the overlapping region of the fields.

  6. Black yeasts and their filamentous relatives: principles of pathogenesis and host defense.

    PubMed

    Seyedmousavi, Seyedmojtaba; Netea, Mihai G; Mouton, Johan W; Melchers, Willem J G; Verweij, Paul E; de Hoog, G Sybren

    2014-07-01

    Among the melanized fungi, the so-called "black yeasts" and their filamentous relatives are particularly significant as agents of severe phaeohyphomycosis, chromoblastomycosis, and mycetoma in humans and animals. The pathogenicity and virulence of these fungi may differ significantly between closely related species. The factors which probably are of significance for pathogenicity include the presence of melanin and carotene, formation of thick cell walls and meristematic growth, presence of yeast-like phases, thermo- and perhaps also osmotolerance, adhesion, hydrophobicity, assimilation of aromatic hydrocarbons, and production of siderophores. Host defense has been shown to rely mainly on the ingestion and elimination of fungal cells by cells of the innate immune system, especially neutrophils and macrophages. However, there is increasing evidence supporting a role of T-cell-mediated immune responses, with increased interleukin-10 (IL-10) and low levels of gamma interferon (IFN-γ) being deleterious during the infection. There are no standardized therapies for treatment. It is therefore important to obtain in vitro susceptibilities of individual patients' fungal isolates in order to provide useful information for selection of appropriate treatment protocols. This article discusses the pathogenesis and host defense factors for these fungi and their severity, chronicity, and subsequent impact on treatment and prevention of diseases in human or animal hosts.

  7. Black Yeasts and Their Filamentous Relatives: Principles of Pathogenesis and Host Defense

    PubMed Central

    Netea, Mihai G.; Mouton, Johan W.; Melchers, Willem J. G.; Verweij, Paul E.; de Hoog, G. Sybren

    2014-01-01

    SUMMARY Among the melanized fungi, the so-called “black yeasts” and their filamentous relatives are particularly significant as agents of severe phaeohyphomycosis, chromoblastomycosis, and mycetoma in humans and animals. The pathogenicity and virulence of these fungi may differ significantly between closely related species. The factors which probably are of significance for pathogenicity include the presence of melanin and carotene, formation of thick cell walls and meristematic growth, presence of yeast-like phases, thermo- and perhaps also osmotolerance, adhesion, hydrophobicity, assimilation of aromatic hydrocarbons, and production of siderophores. Host defense has been shown to rely mainly on the ingestion and elimination of fungal cells by cells of the innate immune system, especially neutrophils and macrophages. However, there is increasing evidence supporting a role of T-cell-mediated immune responses, with increased interleukin-10 (IL-10) and low levels of gamma interferon (IFN-γ) being deleterious during the infection. There are no standardized therapies for treatment. It is therefore important to obtain in vitro susceptibilities of individual patients' fungal isolates in order to provide useful information for selection of appropriate treatment protocols. This article discusses the pathogenesis and host defense factors for these fungi and their severity, chronicity, and subsequent impact on treatment and prevention of diseases in human or animal hosts. PMID:24982320

  8. An Examination of the Relationship between General Life Stress, Racism-Related Stress, and Psychological Health among Black Men

    ERIC Educational Resources Information Center

    Pieterse, Alex L.; Carter, Robert T.

    2007-01-01

    This study explored the relationship among general life stress, racism-related stress, and psychological health in a sample of 220 Black men. Participants completed a personal data form, the Perceived Stress Scale (S. Cohen, T. Kamarck, & R. Mermelstein, 1983), a modified version of the Schedule of Racist Events (H. Landrine & E. A. Klonoff,…

  9. 75 FR 8045 - Hearing on the Department of Justice's Actions Related to the New Black Panther Party Litigation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... From the Federal Register Online via the Government Publishing Office COMMISSION ON CIVIL RIGHTS Hearing on the Department of Justice's Actions Related to the New Black Panther Party Litigation and its Enforcement of Section 11(b) of the Voting Rights Act Correction Notice document 2010-3168 appearing on...

  10. A Local Baseline of the Black Hole Mass Scaling Relations for Active Galaxies. III.The MBH - σ Relation

    NASA Astrophysics Data System (ADS)

    Bennert, Vardha N.; Treu, Tommaso; Auger, Matthew W.; Cosens, Maren; Park, Daeseong; Rosen, Rebecca; Harris, Chelsea E.; Malkan, Matthew A.; Woo, Jong-Hak

    2015-08-01

    We create a baseline of the black hole (BH) mass (MBH)—stellar-velocity dispersion (σ) relation for active galaxies, using a sample of 66 local (0.02relation for our Seyfert-1 galaxy sample has the same intercept and scatter as that of reverberation-mapped AGNs as well as that of quiescent galaxies, consistent with the hypothesis that our single epoch MBH estimator and sample selection function do not introduce significant biases. Barred galaxies, merging galaxies, and those hosting pseudo-bulges do not represent outliers in the MBH-σ relation. This is in contrast with previous work, although no firm conclusion can be drawn on this matter due to the small sample size and limited resolution of the SDSS images.

  11. Motherhood, Psychological Risks, and Resources in Relation to Alcohol Use Disorder: Are There Differences between Black and White Women?

    PubMed

    Balan, Sundari; Widner, Gregory; Chen, Hsing-Jung; Hudson, Darrell; Gehlert, Sarah; Price, Rumi Kato

    2014-04-20

    Rates of alcohol use disorders (AUD) are generally low among women who have ever had children (mothers) compared to women who have never had children (nonmothers), presenting a motherhood advantage. It is unclear if this advantage accrues to "Black" and "White" women alike. Using National Epidemiological Survey on Alcohol and Related Conditions (NESARC) wave 2 cross-sectional data that is rich in alcohol use and psychological measures, we examined the following: (a) if motherhood is protective for past-year AUD among Black (N = 4, 133) and White women (N = 11, 017); (b) potential explanatory psychological mechanisms; and (c) the role of race. Prevalence of a past-year DSM-IV AUD was lower among White mothers compared to White nonmothers, but this same advantage was not observed for Black women. Perceived stress was a risk for all women, but race-ethnic segregated social networks and perceived discrimination predicted current AUD for Black mothers. Unlike White mothers, current psychological factors but not family history of alcohol problems predicted AUD for Black mothers. Future prospective studies should address the mechanisms by which race, motherhood, and psychological factors interactively affect AUD in women.

  12. Selection bias in dynamically-measured super-massive black hole samples: its consequences and the quest for the most fundamental relation

    NASA Astrophysics Data System (ADS)

    Shankar, Francesco; Bernardi, M.; Sheth, R. K.; Weinberg, D. H.; Miralda-Escudé, J.; Ferrarese, L.; Graham, A.; Sesana, A.; Lapi, A.; Marconi, A.; Allevato, V.; Savorgnan, G.; Laesker, R.

    2016-08-01

    We compare the set of local galaxies having dynamically measured black holes with a large, unbiased sample of galaxies extracted from the Sloan Digital Sky Survey. We confirm earlier work showing that the majority of black hole hosts have significantly higher velocity dispersions sigma than local galaxies of similar stellar mass. We use Monte-Carlo simulations to illustrate the effect on black hole scaling relations if this bias arises from the requirement that the black hole sphere of influence must be resolved to measure black hole masses with spatially resolved kinematics. We find that this selection effect artificially increases the normalization of the Mbh-sigma relation by a factor of at least ~3; the bias for the Mbh-Mstar relation is even larger. Our Monte Carlo simulations and analysis of the residuals from scaling relations both indicate that sigma is more fundamental than Mstar or effective radius. In particular, the Mbh-Mstar relation is mostly a consequence of the Mbh-sigma and sigma-Mstar relations, and is heavily biased by up to a factor of 50 at small masses. This helps resolve the discrepancy between dynamically-based black hole-galaxy scaling relations versus those of active galaxies. Our simulations also disfavour broad distributions of black hole masses at fixed sigma. Correcting for this bias suggests that the calibration factor used to estimate black hole masses in active galaxies should be reduced to values of fvir~1. Black hole mass densities should also be proportionally smaller, perhaps implying significantly higher radiative efficiencies/black hole spins. Reducing black hole masses also reduces the gravitational wave signal expected from black hole mergers.

  13. Exploring the genomic diversity of black yeasts and relatives (Chaetothyriales, Ascomycota).

    PubMed

    Teixeira, M M; Moreno, L F; Stielow, B J; Muszewska, A; Hainaut, M; Gonzaga, L; Abouelleil, A; Patané, J S L; Priest, M; Souza, R; Young, S; Ferreira, K S; Zeng, Q; da Cunha, M M L; Gladki, A; Barker, B; Vicente, V A; de Souza, E M; Almeida, S; Henrissat, B; Vasconcelos, A T R; Deng, S; Voglmayr, H; Moussa, T A A; Gorbushina, A; Felipe, M S S; Cuomo, C A; de Hoog, G Sybren

    2017-03-01

    phaeohyphomycosis. An expansion was found in protein degrading peptidase enzyme families S12 (serine-type D-Ala-D-Ala carboxypeptidases) and M38 (isoaspartyl dipeptidases). Based on genomic information, a wide range of abilities of melanin biosynthesis was revealed; genes related to metabolically distinct DHN, DOPA and pyomelanin pathways were identified. The MAT (MAting Type) locus and other sex-related genes were recognized in all 23 black fungi. Members of the asexual genera Fonsecaea and Cladophialophora appear to be heterothallic with a single copy of either MAT-1-1 or MAT-1-2 in each individual. All Capronia species are homothallic as both MAT1-1 and MAT1-2 genes were found in each single genome. The genomic synteny of the MAT-locus flanking genes (SLA2-APN2-COX13) is not conserved in black fungi as is commonly observed in Eurotiomycetes, indicating a unique genomic context for MAT in those species. The heterokaryon (het) genes expansion associated with the low selective pressure at the MAT-locus suggests that a parasexual cycle may play an important role in generating diversity among those fungi.

  14. Relative growth of black holes and the stellar components of galaxies

    NASA Astrophysics Data System (ADS)

    Menci, N.; Fiore, F.; Bongiorno, A.; Lamastra, A.

    2016-10-01

    Recent observations indicate that the mass of supermassive black holes (SMBHs) correlate differently with different galaxy stellar components. Comparing such observations with the results of "ab initio" galaxy formation models can provide insight on the mechanisms leading to the growth of SMBHs. Here we use a state-of-the-art semi-analytic model of galaxy formation to investigate the correlation of the different galaxy stellar components with the mass of the central SMBH. The stellar mass in the disc, in the bulge, and in the pseudo-bulge of galaxies is related to quiescent star formation, to galaxy interactions, and to the loss of angular momentum following disc instabilities, respectively. Consistently with recent findings, we find that while the predicted bulge masses are tightly correlated with the SMBH masses, the correlation between the latter and the galactic discs shows a much larger scatter, in particular when bulgeless galaxies are considered. In addition, we obtain that the predicted masses of pseudo-bulges shows little or no-correlation with the masses of SMBHs. We track the histories of merging, star formation, and SMBH accretion to investigate the physical processes at the origin of such findings within the context of cosmological models of galaxy formation. Finally, we discuss the effects of variations of our assumed fiducial model on the results.

  15. On the theoretical framework of magnetized outflows from stellar-mass black holes and related observations

    NASA Astrophysics Data System (ADS)

    Christodoulou, D. M.; Contopoulos, I.; Kazanas, D.; Steiner, J. F.; Papadopoulos, D. B.; Laycock, S. G. T.

    2016-09-01

    The spins of stellar-mass black holes (BHs) and the power outputs of their jets are measurable quantities. Unfortunately, the currently employed methods do not agree and the results are controversial. Two major issues concern the measurements of BH spin and beam (jet) power. The former issue can be resolved by future observations. But the latter issue can be resolved now, if we pay attention to what is expected from theoretical considerations. The question of whether a correlation has been found between the power outputs of few objects and the spins of their BHs is moot because BH beam power does not scale with the square of the spin of the BH. We show that the theoretical BH beam power is a strongly non-linear function of spin that cannot be approximated by a quadratic relation, as is generally stated when the influence of the magnetic field is not accounted for in the Blandford & Znajek model. The BH beam power of ballistic jets should scale a lot more steeply with BH spin irrespective of the magnetic field assumed to thread the horizon and the spin range considered. This behaviour may already be visible in the analyses of radio observations by Narayan & McClintock and Russell et al. In agreement with previous studies, we also find that the power output that originates in the inner regions of the surrounding accretion discs is higher than that from the BHs and it cannot be ignored in investigations of continuous compact jets from these systems.

  16. Validating the effective-one-body model of spinning, precessing binary black holes against numerical relativity

    NASA Astrophysics Data System (ADS)

    Babak, Stanislav; Taracchini, Andrea; Buonanno, Alessandra

    2017-01-01

    In Abbott et al. [Phys. Rev. X 6, 041014 (2016), 10.1103/PhysRevX.6.041014], the properties of the first gravitational wave detected by LIGO, GW150914, were measured by employing an effective-one-body (EOB) model of precessing binary black holes whose underlying dynamics and waveforms were calibrated to numerical-relativity (NR) simulations. Here, we perform the first extensive comparison of such an EOBNR model to 70 precessing NR waveforms that span mass ratios from 1 to 5, dimensionless spin magnitudes up to 0.5, generic spin orientations, and length of about 20 orbits. We work in the observer's inertial frame and include all ℓ=2 modes in the gravitational-wave polarizations. We introduce new prescriptions for the EOB ringdown signal concerning its spectrum and time of onset. For total masses between 10 M⊙ and 200 M⊙ , we find that precessing EOBNR waveforms have unfaithfulness within about 3% to NR waveforms when considering the Advanced-LIGO design noise curve. This result is obtained without recalibration of the inspiral-plunge signal of the underlying nonprecessing EOBNR model. The unfaithfulness is computed with maximization over time and phase of arrival, sky location, and polarization of the EOBNR waveform, and it is averaged over sky location and polarization of the NR signal. We also present comparisons between NR and EOBNR waveforms in a frame that tracks the orbital precession.

  17. Diet-related die-off of captive black-crowned night herons

    USGS Publications Warehouse

    Carpenter, J.W.; Spann, J.W.; Novilla, M.N.

    1979-01-01

    Several species of herons, which are top-level consumers in aquatic food chains, have experienced population declines in certain areas o f their normal range (7,13) -- areas in which elevated levels of various environmental pollutants are known to occur. (6) To determine the effects of environmental contaminants on the Ardeidae, a colony of black-crowned night herons (Nycticorax nycticorax) was established in 1972 at the Patuxent Wildlife Research Center. The night heron was selected as the model species because of its widespread occurrence and its ability to survive and reproduce in captivity. Birds for the colony were obtained from either the New York Zoological Park and Dallas Zoo or were wild-caught along the Maryland and Virginia coasts in 1972, 1973, and 1975. This report describes a die-off in the colony following a change in the origina of their food source. The data suggest that the mortality was diet-related, most likely caused by vitamin E deficiency. Excessive dietary thiaminase may have resulted in concurrent thiamine deficiency, but evidence for this is equivocal.

  18. Employment gains and wage declines: the erosion of black women's relative wages since 1980.

    PubMed

    Pettit, Becky; Ewert, Stephanie

    2009-08-01

    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.

  19. The Local Black Hole Mass Function Derived from the MBH-Pitch Angle and the MBH-Sersic Index Relations

    NASA Astrophysics Data System (ADS)

    Mutlu Pakdil, Burcin; Seigar, Marc S.; Davis, Benjamin L.

    2016-01-01

    We determined the local supermassive black hole mass function (BHMF) for all galaxy types with complementing the local BHMF for spiral galaxies derived by Davis et al. (2014). We used the empirical relation between supermassive black hole mass and the Sersic index for early type (E/S0) galaxies from the same parent sample with Davis et al. (2014), which is selected from galaxies in the Carnegie-Irvine Galaxy Survey (CGS) which is a very complete sample of the nearby galaxies.The observational simplicity of our approach and direct measurements from the statistically tightest correlations with black hole mass, which are the Sersic index for E/S0 galaxies and pitch angle for spiral galaxies, make it straightforward to estimate an accurate local BHMF. Integrating over the best-fitting mass function, the local mass density of SMBHs from early- and late-type galaxies combined is ρ=3.61+3.80-1.75 x105 M⊙ Mpc-3. The errors are estimated from Monte Carlo simulations which include uncertainities in the emprical relations and measurement errors in both Sersic index and Pitch angle. Assuming supermassive black holes form via baryonic accretion, we find that 0.013+0.013-0.006 per cent of baryons are contained in SMBHs at the centers of galaxies in the local universe.

  20. RELATIONS BETWEEN CENTRAL BLACK HOLE MASS AND TOTAL GALAXY STELLAR MASS IN THE LOCAL UNIVERSE

    SciTech Connect

    Reines, Amy E.; Volonteri, Marta

    2015-11-10

    Scaling relations between central black hole (BH) mass and host galaxy properties are of fundamental importance to studies of BH and galaxy evolution throughout cosmic time. Here we investigate the relationship between BH mass and host galaxy total stellar mass using a sample of 262 broad-line active galactic nuclei (AGNs) in the nearby universe (z < 0.055), as well as 79 galaxies with dynamical BH masses. The vast majority of our AGN sample is constructed using Sloan Digital Sky Survey spectroscopy and searching for Seyfert-like narrow-line ratios and broad Hα emission. BH masses are estimated using standard virial techniques. We also include a small number of dwarf galaxies with total stellar masses M{sub stellar} ≲ 10{sup 9.5} M{sub ⊙} and a subsample of the reverberation-mapped AGNs. Total stellar masses of all 341 galaxies are calculated in the most consistent manner feasible using color-dependent mass-to-light ratios. We find a clear correlation between BH mass and total stellar mass for the AGN host galaxies, with M{sub BH} ∝ M{sub stellar}, similar to that of early-type galaxies with dynamically detected BHs. However, the relation defined by the AGNs has a normalization that is lower by more than an order of magnitude, with a BH-to-total stellar mass fraction of M{sub BH}/M{sub stellar} ∼ 0.025% across the stellar mass range 10{sup 8} ≤ M{sub stellar}/M{sub ⊙} ≤ 10{sup 12}. This result has significant implications for studies at high redshift and cosmological simulations in which stellar bulges cannot be resolved.

  1. The evaluation of Pat-Pat related injuries in the western black sea region of Turkey

    PubMed Central

    2011-01-01

    Background Accidents caused by motorized vehicle in the agricultural sector are frequently observed. In Turkey; accidents arising from motorized vehicles, named Pat-Pat, which are used by farmers in the Western Black Sea region is not unusual. Methods One hundred five patients who were brought into the Emergency Department of Duzce University, Medical Faculty Hospital between September 2009 and August 2010 due to Pat-Pat related accidents were evaluated. Results The cases consisted of 73 (69.5%) males and 32 (30.5%) females, ranging from 2 to 73 years of age. In the 10-39 age group, a total of 63 (60.0%) cases were determined. The months when the greatest rate of cases applied to the hospital consisted of July, August, September and the season is summer. The cases were exposed to trauma in roads in 54 (51.4%), and 51 (48.6%) occurred in agricultural area without roads. Eighty seven (82.9%) cases were injured due to the overturning of vehicle. The patients were brought to the hospital using a private vehicle in 54 (51.4%) of the cases and in 51 (48.6%) cases, 112 ambulance system was used. The cases were determined to apply to the hospital most frequently between 6 pm-12 am. The injuries frequently consisted of head-neck and spine traumas, thorax traumas and upper extremity traumas. In 55 (52.4%) cases, open wound-laceration was determined. Seventy five (71.4%) cases were treated in the Emergency Department, and 28 (26.7%) were hospitalized. Three (2.9%) cases were deceased. Conclusions Serious injuries can occur in Pat-Pat related accidents, and careful systematic physical examination should be conducted. In order to prevent these accidents, education of farm operators and engineering studies on the mechanics and safety of these vehicles should be taken and legal regulations should be created. PMID:21699689

  2. Cosmic Evolution of Black Holes And Spheroids. 1, the M(BH)-Sigma Relation at Z=0.36

    SciTech Connect

    Woo, Jong-Hak; Treu, Tommaso; Malkan, Matthew A.; Blandford, Roger D.; /KIPAC, Menlo Park

    2006-04-17

    We test the evolution of the correlation between black hole mass and bulge velocity dispersion (M{sub BH} - {sigma}), using a carefully selected sample of 14 Seyfert 1 galaxies at z = 0.36 {+-} 0.01. We measure velocity dispersion from stellar absorption lines around Mgb (5175 {angstrom}) and Fe (5270 {angstrom}) using high S/N Keck spectra, and estimate black hole mass from the H{beta} line width and the optical luminosity at 5100 {angstrom}, based on the empirically calibrated photo-ionization method. We find a significant offset from the local relation, in the sense that velocity dispersions were smaller for given black hole masses at z = 0.36 than locally. We investigate various sources of systematic uncertainties and find that those cannot account for the observed offset. The measured offset is {Delta} log M{sub BH} = 0.62 {+-} 0.10 {+-} 0.25, i.e. {Delta} log {sigma} = 0.15 {+-} 0.03 {+-} 0.06, where the error bars include a random component and an upper limit to the systematics. At face value, this result implies a substantial growth of bulges in the last 4 Gyr, assuming that the local M{sub BH} - {sigma} relation is the universal evolutionary end-point. Along with two samples of active galaxies with consistently determined black hole mass and stellar velocity dispersion taken from the literature, we quantify the observed evolution with the best fit linear relation, {Delta} log M{sub BH} = (1.66 {+-} 0.43)z + (0.04 {+-} 0.09) with respect to the local relationship of Tremaine et al. (2002), and {Delta} log M{sub BH} = (1.55 {+-} 0.46)z +(0.01 {+-} 0.12) with respect to that of Ferrarese (2002). This result is consistent with the growth of black holes predating the final growth of bulges at these mass scales (<{sigma}> = 170 km s{sup -1}).

  3. Correlates of Age Onset of Type 2 Diabetes Among Relatively Young Black and White Adults in a Community

    PubMed Central

    Nguyen, Quoc Manh; Xu, Ji-Hua; Chen, Wei; Srinivasan, Sathanur R.; Berenson, Gerald S.

    2012-01-01

    OBJECTIVE The risk factors for middle-age onset of type 2 diabetes are well known. However, information is scant regarding the age onset of type 2 diabetes and its correlates in community-based black and white relatively young adults. RESEARCH DESIGN AND METHODS This prospective cohort study consisted of normoglycemic (n = 2,459) and type 2 diabetic (n = 144) adults aged 18–50 years who were followed for an average of 16 years. RESULTS The incidence rate of the onset of type 2 diabetes was 1.6, 4.3, 3.9, and 3.4 per 1,000 person-years for age-groups 18–29, 30–39, and 40–50 and total sample, respectively. Incidences of diabetes increased with age by race and sex groups (P for trend ≤0.01); higher in black females versus white females and blacks versus whites in total sample (P < 0.05). In a multivariable Cox model, baseline parental diabetes (hazard ratio [HR] 5.24) and plasma insulin were significantly associated with diabetes incidence at the youngest age (18–29 years); black race, BMI, and glucose at age 30–39 years; female sex, parental diabetes (HR 2.44), BMI, ratio of triglycerides and HDL cholesterol (TG/HDL-C ratio), and glucose at age 40–50 years; and black race, parental diabetes (HR 2.44), BMI, TG/HDL-C ratio, and glucose in whole cohort. Further, patients with diabetes, regardless of age onset, displayed a significantly higher prevalence of maternal history of diabetes at baseline (P < 0.01). CONCLUSIONS In relatively young adults, predictability of baseline cardiometabolic risk factors along with race, sex, and parental history of diabetes for the onset of type 2 diabetes varied by age-group. These findings have implications for early prevention and intervention in relatively young adults. PMID:22399694

  4. THE SUPERMASSIVE BLACK HOLE MASS-SPHEROID STELLAR MASS RELATION FOR SERSIC AND CORE-SERSIC GALAXIES

    SciTech Connect

    Scott, Nicholas; Graham, Alister W; Schombert, James

    2013-05-01

    We have examined the relationship between supermassive black hole mass (M{sub BH}) and the stellar mass of the host spheroid (M{sub sph,*}) for a sample of 75 nearby galaxies. To derive the spheroid stellar masses we used improved Two Micron All Sky Survey K{sub s}-band photometry from the ARCHANGEL photometry pipeline. Dividing our sample into core-Sersic and Sersic galaxies, we find that they are described by very different M{sub BH}-M{sub sph,*} relations. For core-Sersic galaxies-which are typically massive and luminous, with M{sub BH} {approx}> 2 Multiplication-Sign 10{sup 8} M{sub Sun }-we find M{sub BH}{proportional_to} M{sub sph,*}{sup 0.97{+-}0.14}, consistent with other literature relations. However, for the Sersic galaxies-with typically lower masses, M{sub sph,*} {approx}< 3 Multiplication-Sign 10{sup 10} M{sub Sun }-we find M{sub BH}{proportional_to}M{sub sph,*}{sup 2.22{+-}0.58}, a dramatically steeper slope that differs by more than 2 standard deviations. This relation confirms that, for Sersic galaxies, M{sub BH} is not a constant fraction of M{sub sph,*}. Sersic galaxies can grow via the accretion of gas which fuels both star formation and the central black hole, as well as through merging. Their black hole grows significantly more rapidly than their host spheroid, prior to growth by dry merging events that produce core-Sersic galaxies, where the black hole and spheroid grow in lockstep. We have additionally compared our Sersic M{sub BH}-M{sub sph,*} relation with the corresponding relation for nuclear star clusters, confirming that the two classes of central massive object follow significantly different scaling relations.

  5. 'Triply cursed': racism, homophobia and HIV-related stigma are barriers to regular HIV testing, treatment adherence and disclosure among young Black gay men.

    PubMed

    Arnold, Emily A; Rebchook, Gregory M; Kegeles, Susan M

    2014-06-01

    In the USA, young Black gay men are disproportionately impacted upon by HIV. In this qualitative study consisting of in-depth interviews with 31 young Black gay men and nine service providers, where we used thematic analysis to guide our interpretations, we found that HIV-related stigma and homophobia, within the larger societal context of racism, were related to sexual risk behaviour, reluctance to obtain HIV testing or care, lower adherence to treatment medication, and non-disclosure of a positive HIV status to sexual partners. Participants experienced homophobia and HIV-related stigma from churches and families within the Black community and from friends within the Black gay community, which otherwise provide support in the face of racism. Vulnerability to HIV was related to strategies that young Black gay men enacted to avoid being stigmatised or as a way of coping with alienation and rejection.

  6. Black holes and fundamental fields in numerical relativity: Initial data construction and evolution of bound states

    NASA Astrophysics Data System (ADS)

    Okawa, Hirotada; Witek, Helvi; Cardoso, Vitor

    2014-05-01

    Fundamental fields are a natural outcome in cosmology and particle physics and might therefore serve as a proxy for more complex interactions. The equivalence principle implies that all forms of matter gravitate, and one therefore expects relevant, universal imprints of new physics in strong field gravity, such as that encountered close to black holes. Fundamental fields in the vicinities of supermassive black holes give rise to extremely long-lived, or even unstable, configurations, which slowly extract angular momentum from the black hole or simply evolve nonlinearly over long time scales, with important implications for particle physics and gravitational-wave physics. Here, we perform a fully nonlinear study of scalar-field condensates around rotating black holes. We provide novel ways to specify initial data for the Einstein—Klein—Gordon system, with potential applications in a variety of scenarios. Our numerical results confirm the existence of long-lived bar modes, which act as lighthouses for gravitational wave emission: the scalar field condenses outside the black hole geometry and acts as a constant frequency gravitational-wave source for very long time scales. This effect could turn out to be a potential signature of beyond standard model physics and also a promising source of gravitational waves for future gravitational-wave detectors.

  7. A SCALING RELATION BETWEEN MEGAMASER DISK RADIUS AND BLACK HOLE MASS IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Wardle, Mark; Yusef-Zadeh, Farhad E-mail: zadeh@northwestern.edu

    2012-05-10

    Several thin, Keplerian, sub-parsec megamaser disks have been discovered in the nuclei of active galaxies and used to precisely determine the mass of their host black holes. We show that there is an empirical linear correlation between the disk radius and the black hole mass. We demonstrate that such disks are naturally formed by the partial capture of molecular clouds passing through the galactic nucleus and temporarily engulfing the central supermassive black hole. Imperfect cancellation of the angular momenta of the cloud material colliding after passing on opposite sides of the hole leads to the formation of a compact disk. The radial extent of the disk is determined by the efficiency of this process and the Bondi-Hoyle capture radius of the black hole, and naturally produces the empirical linear correlation of the radial extent of the maser distribution with black hole mass. The disk has sufficient column density to allow X-ray irradiation from the central source to generate physical and chemical conditions conducive to the formation of 22 GHz H{sub 2}O masers. For initial cloud column densities {approx}< 10{sup 23.5} cm{sup -2} the disk is non-self-gravitating, consistent with the ordered kinematics of the edge-on megamaser disks; for higher cloud columns the disk would fragment and produce a compact stellar disk similar to that observed around Sgr A* at the galactic center.

  8. Winter movements of American black ducks in relation to natural and impounded wetlands in New Jersey

    USGS Publications Warehouse

    Conroy, M.J.; Costanzo, G.R.; Stotts, D.B.; Whitman, William R.; Meredith, William H.

    1987-01-01

    Radio telemetry was used to follow the movements and habitat use of female American Black ducks (Anas rubripes) trapped at Brigantine Division. Edwin B. Forsythe NWR (BNW) during three field seasons (1983-1896). Use of the BNWR impoundments was strongly associated with open vs. closed hunting seasons and with presence or absence of ice cover. Black ducks primarily used the impoundments for daytime roost sites and fed in saltmarsh areas at night during the hunting season. Following the hunting season use generally dispersed to saltmarsh and inland freshwater habitats. Freeze-up of the impoundments resulted in dispersal of black ducks to saltmarsh, inland freshwater, or areas to the south of New Jersey. We conclude that the BNWR impoundments only partially meet the habitat requirements of wintering black ducks. Access to saltmarsh habitats for feeding, and to inland freshwater habitats during periods of hard freeze, may be critical. The utility of the BNWR impoundments to black ducks, needs to be considered in conjunction with the availability of these other important habitats.

  9. A prospective epidemiological study on odontogenic tumours in a black African population, with emphasis on the relative frequency of ameloblastoma.

    PubMed

    Oginni, F O; Stoelinga, P J W; Ajike, S A; Obuekwe, O N; Olokun, B Aluko; Adebola, R A; Adeyemo, W L; Fasola, O; Adesina, O A; Akinbami, B O; Iwegbu, I O; Ogunmuyiwa, S A; Obimakinde, O S; Uguru, C C

    2015-09-01

    The persistent view in the literature is that the relative frequency of ameloblastomas is higher in the black population than in Caucasians. The aim of this study was to determine the relative frequency of all odontogenic tumours (OT) in a 100% black population and to compare our findings with those of previous studies. A prospective study was undertaken of all patients presenting with OT to all 16 Nigerian departments of oral and maxillofacial surgery over a 4-year period. The following data were obtained: patient demographics, delay to presentation, extent of the lesion, and histological diagnosis. Six hundred and twenty-two cases were studied. A slight male preponderance was observed (male to female ratio 1.17:1). Patients ranged in age from 5 to 89 years, with a peak incidence in the third decade. The relative frequency of OT was 0.99 per million and that of ameloblastoma was 0.76 per million. Ameloblastoma was the most prevalent OT (76.5%), followed by adenomatoid odontogenic tumours (5.6%), odontogenic myxoma (4.5%), and keratocystic odontogenic tumours (KCOT) (3.1%). The relative frequency of ameloblastoma among Nigerians was not different from frequencies reported previously among Caucasian and Tanzanian black populations. KCOTs were, however, rarely diagnosed in Nigerians as compared to the white population in the Western world.

  10. Do US Black Women Experience Stress-Related Accelerated Biological Aging?

    PubMed Central

    Hicken, Margaret T.; Pearson, Jay A.; Seashols, Sarah J.; Brown, Kelly L.; Cruz, Tracey Dawson

    2010-01-01

    We hypothesize that black women experience accelerated biological aging in response to repeated or prolonged adaptation to subjective and objective stressors. Drawing on stress physiology and ethnographic, social science, and public health literature, we lay out the rationale for this hypothesis. We also perform a first population-based test of its plausibility, focusing on telomere length, a biomeasure of aging that may be shortened by stressors. Analyzing data from the Study of Women's Health Across the Nation (SWAN), we estimate that at ages 49–55, black women are 7.5 years biologically “older” than white women. Indicators of perceived stress and poverty account for 27% of this difference. Data limitations preclude assessing objective stressors and also result in imprecise estimates, limiting our ability to draw firm inferences. Further investigation of black-white differences in telomere length using large-population-based samples of broad age range and with detailed measures of environmental stressors is merited. PMID:20436780

  11. Green and black tea intake in relation to prostate cancer risk among Singapore Chinese

    PubMed Central

    Montague, Julia A.; Wu, Anna H.; Genkinger, Jeanine M.; Koh, Woon-Puay; Wong, Alvin S.; Wang, Renwei; Yuan, Jian-Min; Yu, Mimi C.

    2013-01-01

    Purpose Tea is one of the most commonly consumed beverages worldwide. To date, observational data from prospective cohort studies investigating the relationship between green and black tea intake and prostate cancer risk are sparse and equivocal. In a population-based, prospective cohort study of Chinese men in Singapore, we investigated the relationship between green and black tea intake and prostate cancer risk. Methods Tea consumption data for 27,293 men were collected at baseline (between 1993 and 1998) using a validated food frequency questionnaire. After an average of 11.2 years of follow-up, 298 men had developed prostate cancer. Proportional hazards regression methods were used to assess the associations between tea intake and prostate cancer risk. Results There was no association between daily green tea intake and prostate cancer risk, compared with no green tea intake [hazard ratio (HR) = 1.08; 95 % confidence interval (CI) 0.79, 1.47]. For black tea, a statistically significant positive association and trend were observed for daily intake compared with no black tea intake (HR = 1.41, 95 % CI 1.03, 1.92; p for trend <0.01) Conclusions Few prospective data are available from populations that have both a high level and wide range of black and green tea intake; this study represents a unique opportunity to evaluate their individual effects on prostate cancer risk. Our findings support the notion that green tea intake does not protect against prostate cancer and that black tea intake may increase prostate cancer risk. PMID:22864870

  12. Alcohol outlet density and related use in an urban Black population in Philadelphia public housing communities

    PubMed Central

    Cederbaum, Julie A.; Petering, Robin; Hutchinson, M. Katherine; He, Amy S.; Wilson, John P.; Jemmott, John B.; Jemmott, Loretta Sweet

    2014-01-01

    Adolescent alcohol use behaviors are influenced by familial patterns and neighborhood factors. This work explored the influence of individual, family, and environment on alcohol use. Baseline data from a randomized controlled trial with Black mothers son dyads (n=382) were paired with census tract and alcohol control board data. Among mothers, younger age, along with neighborhood factors of alcohol outlet density, race, and education were significantly associated with use. Among sons, older age and alcohol outlet density in the neighborhood predicted use. Findings highlight neighborhood influence, beyond family qualities, as a significant determinant of disadvantaged Black mothers’ alcohol use. Implications for public health policy are discussed. PMID:25463915

  13. How Adaptive and Maladaptive Perfectionism Relate to Positive and Negative Psychological Functioning: Testing a Stress-Mediation Model in Black and White Female College Students

    ERIC Educational Resources Information Center

    Chang, Edward C.; Watkins, Angela; Banks, Kira Hudson

    2004-01-01

    This study assessed racial variations in how adaptive and maladaptive perfectionism relate to psychological functioning in a sample of 150 Black and 150 White female college students. Comparative results indicated that Black women, as compared with White women, reported less adaptive perfectionism, less life satisfaction, greater stress, and…

  14. Spectral methods in general relativity and large Randall-Sundrum II black holes

    SciTech Connect

    Abdolrahimi, Shohreh; Cattoën, Céline; Page, Don N.; Yaghoobpour-Tari, Shima E-mail: celine.cattoen-gilbert@canterbury.ac.nz E-mail: yaghoobp@ualberta.ca

    2013-06-01

    Using a novel numerical spectral method, we have found solutions for large static Randall-Sundrum II (RSII) black holes by perturbing a numerical AdS{sub 5}-CFT{sub 4} solution to the Einstein equation with a negative cosmological constant Λ that is asymptotically conformal to the Schwarzschild metric. We used a numerical spectral method independent of the Ricci-DeTurck-flow method used by Figueras, Lucietti, and Wiseman for a similar numerical solution. We have compared our black-hole solution to the one Figueras and Wiseman have derived by perturbing their numerical AdS{sub 5}-CFT{sub 4} solution, showing that our solution agrees closely with theirs. We have obtained a closed-form approximation to the metric of the black hole on the brane. We have also deduced the new results that to first order in 1/(−ΛM{sup 2}), the Hawking temperature and entropy of an RSII static black hole have the same values as the Schwarzschild metric with the same mass, but the horizon area is increased by about 4.7/(−Λ)

  15. Comparative Studies of Blacks and Whites in the United States. Quantitative Studies in Social Relations Series.

    ERIC Educational Resources Information Center

    Miller, Kent S., Ed.; Dreger, Ralph Mason, Ed.

    The contents of this book are organized in seventeen chapters, as follows: (1) "Perspective and Overview," K. S. Miller and R. M. Dreger; (2) "Racial Experimenter Effects," J. M. Sattler; (3) "Behavior-genetic Analysis and its Biosocial Consequences," J. Hirsch; (4) Biological Substrata," R. M. Malina; (5) "Language Abilities of Black Americans,"…

  16. Relational Mentoring of Doctoral Social Work Students at Historically Black Colleges and Universities

    ERIC Educational Resources Information Center

    Ross-Sheriff, Fariyal; Berry Edwards, Janice; Orme, Julie

    2017-01-01

    This article explores the distinctive mentoring experiences of social work doctoral students at historically black colleges and universities (HBCUs). With a philosophical emphasis on social justice, self-determination, racial identity and pride, and social integration, social work faculty at HBCUs mentor African American and other students in PhD…

  17. The relative role of galaxy mergers and cosmic flows in feeding black holes

    SciTech Connect

    Bellovary, Jillian; Brooks, Alyson; Volonteri, Marta; Governato, Fabio; Quinn, Thomas; Wadsley, James

    2013-12-20

    Using a set of zoomed-in cosmological simulations of high-redshift progenitors of massive galaxies, we isolate and trace the history of gas that is accreted by central supermassive black holes. We determine the origins of the accreted gas, in terms of whether it entered the galaxy during a merger event or was smoothly accreted. Furthermore, we designate whether the smoothly accreted gas is accreted via a cold flow or is shocked upon entry into the halo. For moderate-mass (10{sup 6}-10{sup 7} M {sub ☉}) black holes at z ∼ 4, there is a preference to accrete cold flow gas as opposed to gas of shocked or merger origin. However, this result is a consequence of the fact that the entire galaxy has a higher fraction of gas from cold flows. In general, each black hole tends to accrete the same fractions of smooth- and merger-accreted gas as is contained in its host galaxy, suggesting that once gas enters a halo it becomes well-mixed, and its origins are erased. We find that the angular momentum of the gas upon halo entry is a more important factor; black holes preferentially accrete gas that had low angular momentum when it entered the galaxy, regardless of whether it was accreted smoothly or through mergers.

  18. On Relating Health Care Policy to the Provision of Health Care to Black Families.

    ERIC Educational Resources Information Center

    Darity, William A.

    This paper addresses health and social issues as well as other socioeconomic problems which affect the black family, and the development of appropriate policy and programs to deal with those problems. Data on infant mortality, life expectancy, maternal mortality, physician and dental visits, and some selected death rates from specific causes are…

  19. The Relative Economic Status of Chinese, Japanese, Black, and White Men in California.

    ERIC Educational Resources Information Center

    Wong, Harold H.

    This study hypothesizes that Chinese, Japanese, and blacks in California earn less at each level of education and age than do whites, and that the situation is not improving. Hypothesized reasons include a lower return on education, exclusion from high earning occupations, nonadvancement within an occupation, and greater unemployment. A basic…

  20. The overlap of numerical relativity, perturbation theory and post-Newtonian theory in the binary black hole problem

    NASA Astrophysics Data System (ADS)

    Le Tiec, Alexandre

    2014-09-01

    Inspiralling and coalescing binary black holes are promising sources of gravitational radiation. The orbital motion and gravitational-wave emission of such system can be modeled using a variety of approximation schemes and numerical methods in general relativity: The post-Newtonian (PN) formalism, black hole perturbation theory (BHP), numerical relativity (NR) simulations and the effective one-body (EOB) model. We review recent work at the multiple interfaces of these analytical and numerical techniques, emphasizing the use of coordinate-invariant relationships to perform meaningful comparisons. Such comparisons provide independent checks of the validity of the various calculations, they inform the development of a universal, semi-analytical model of the binary dynamics and gravitational-wave emission and they help to delineate the respective domains of validity of each approximation method. For instance, several recent comparisons suggest that perturbation theory may find applications in a broader range of physical problems than previously thought, including the radiative inspiral of intermediate mass-ratio and comparable-mass black hole binaries.

  1. Radiative, two-temperature simulations of low-luminosity black hole accretion flows in general relativity

    NASA Astrophysics Data System (ADS)

    Sądowski, Aleksander; Wielgus, Maciek; Narayan, Ramesh; Abarca, David; McKinney, Jonathan C.; Chael, Andrew

    2017-04-01

    We present a numerical method that evolves a two-temperature, magnetized, radiative, accretion flow around a black hole, within the framework of general relativistic radiation magnetohydrodynamics. As implemented in the code KORAL, the gas consists of two sub-components - ions and electrons - which share the same dynamics but experience independent, relativistically consistent, thermodynamical evolution. The electrons and ions are heated independently according to a prescription from the literature for magnetohydrodynamical turbulent dissipation. Energy exchange between the particle species via Coulomb collisions is included. In addition, electrons gain and lose energy and momentum by absorbing and emitting synchrotron and bremsstrahlung radiation and through Compton scattering. All evolution equations are handled within a fully covariant framework in the relativistic fixed-metric space-time of the black hole. Numerical results are presented for five models of low-luminosity black hole accretion. In the case of a model with a mass accretion rate dot{M}˜ 4× 10^{-8} dot{M}_Edd, we find that radiation has a negligible effect on either the dynamics or the thermodynamics of the accreting gas. In contrast, a model with a larger dot{M}˜ 4× 10^{-4} dot{M}_Edd behaves very differently. The accreting gas is much cooler and the flow is geometrically less thick, though it is not quite a thin accretion disc.

  2. COSMIC EVOLUTION OF BLACK HOLES AND SPHEROIDS. V. THE RELATION BETWEEN BLACK HOLE MASS AND HOST GALAXY LUMINOSITY FOR A SAMPLE OF 79 ACTIVE GALAXIES

    SciTech Connect

    Park, Daeseong; Woo, Jong-Hak; Bennert, Vardha N.; Treu, Tommaso; Auger, Matthew W.; Malkan, Matthew A. E-mail: woo@astro.snu.ac.kr E-mail: vbennert@calpoly.edu E-mail: malkan@astro.ucla.edu

    2015-02-01

    We investigate the cosmic evolution of the black hole (BH) mass-bulge luminosity relation using a sample of 52 active galaxies at z ∼ 0.36 and z ∼ 0.57 in the BH mass range of 10{sup 7.4}-10{sup 9.1} M {sub ☉}. By consistently applying multicomponent spectral and structural decomposition to high-quality Keck spectra and high-resolution Hubble Space Telescope images, BH masses (M {sub BH}) are estimated using the Hβ broad emission line combined with the 5100 Å nuclear luminosity, and bulge luminosities (L {sub bul}) are derived from surface photometry. Comparing the resulting M {sub BH} – L {sub bul} relation to local active galaxies and taking into account selection effects, we find evolution of the form M {sub BH}/L {sub bul}∝(1 + z){sup γ} with γ = 1.8 ± 0.7, consistent with BH growth preceding that of the host galaxies. Including an additional sample of 27 active galaxies with 0.5 < z < 1.9 taken from the literature and measured in a consistent way, we obtain γ = 0.9 ± 0.7 for the M {sub BH} – L {sub bul} relation and γ = 0.4 ± 0.5 for the M {sub BH}-total host galaxy luminosity (L {sub host}) relation. The results strengthen the findings from our previous studies and provide additional evidence for host galaxy bulge growth being dominated by disk-to-bulge transformation via minor mergers and/or disk instabilities.

  3. Scaling relations between black holes and their host galaxies: comparing theoretical and observational measurements, and the impact of selection effects

    NASA Astrophysics Data System (ADS)

    DeGraf, C.; Di Matteo, T.; Treu, T.; Feng, Y.; Woo, J.-H.; Park, D.

    2015-11-01

    We use the high-resolution simulation MassiveBlackII to examine scaling relations between black hole (BH) mass and host galaxy properties (σ, total M* and LV), finding good agreement with recent observational data, especially at the high-mass end. We find Gaussian intrinsic scatter (˜half the observed scatter) about all three relations, except among the most massive objects. Below z ˜ 2 the slope of the relations remain roughly z-independent, and only steepen by 50 per cent by z ˜ 4. The normalization of the σ, LV relations evolve by 0.3, 0.43 dex, while the M* correlation does not evolve out to at least z ˜ 2. Testing for selection biases, we find MBH- or M*-selected samples have steeper slopes than random samples, suggesting a constant-mass selection function can exhibit faster evolution than a random sample. We find a potential bias among high-LBH subsamples due to their more massive hosts, but that bright (active) active galactic nuclei exhibit no intrinsic bias relative to fainter (inactive) BHs in equivalent-mass hosts. Finally, we show that BHs below the local relation tend to grow faster than their host (72 per cent of BHs >0.3 dex below the mean relation have an MBH-M* trajectory steeper than the local relation), while those above have shallower trajectories (only 14 per cent are steeper than local). Thus BHs tend to grow faster than their hosts until surpassing the local relation, when their growth is suppressed, bringing them back towards the mean relation.

  4. Why Black Officers Still Fail

    DTIC Science & Technology

    2010-03-01

    White youth is smaller than it once was. They all pointed to the fact that today’s youth, both white and black, tend to be attracted to rap music and...papers touching on the experiences of black officers as they relate to representation, promotions, influence , and culture. They can best be...they relate to Black officer representation in the Army, Black officer promotion rates, Black officer influence on policy and decision making, black

  5. Perceived racial, sexual identity, and homeless status-related discrimination among Black adolescents and young adults experiencing homelessness: Relations with depressive symptoms and suicidality.

    PubMed

    Gattis, Maurice N; Larson, Andrea

    2016-01-01

    There is a dearth of empirical evidence that addresses how racial minority, sexual minority, and homeless statuses, with their accompanying experiences of stigma and discrimination, are related to mental health in adolescent and young adult populations. The current study addresses this gap by examining the associations between multiple forms of discrimination, depressive symptoms, and suicidality in a sample of 89 Black adolescents and young adults (52% female; 47% nonheterosexual, ages 16-24) experiencing homelessness. Results from a series of ordinary least squares and logistic regressions suggested that perceived homelessness stigma and racial discrimination were associated with higher levels of depressive symptoms, controlling for gender, age, and other types of discrimination, while perceived sexual identity discrimination showed no association. Having ever spent a homeless night on the street, an indicator of homelessness severity, accounted for a substantial amount of the association between homelessness stigma and depressive symptoms. In contrast, suicidality was not significantly associated with any measure of discrimination, homelessness severity, or personal characteristics. We also found no indication that the associations between perceived discrimination targeted at racial and homelessness statuses and mental health differed by sexual minority status. Our results suggest that depressive symptoms and suicidality are prevalent among Black homeless youth, and that depressive symptoms are particularly associated with racial discrimination and indicators of homelessness. The roles of discrimination and a lack of safe housing may be taken into account when designing programs and policies that address the mental health of Black adolescents and young adults experiencing homelessness.

  6. Intermediate-mass-ratio black-hole binaries: numerical relativity meets perturbation theory.

    PubMed

    Lousto, Carlos O; Nakano, Hiroyuki; Zlochower, Yosef; Campanelli, Manuela

    2010-05-28

    We study black-hole binaries in the intermediate-mass-ratio regime 0.01≲q≲0.1 with a new technique that makes use of nonlinear numerical trajectories and efficient perturbative evolutions to compute waveforms at large radii for the leading and nonleading (ℓ, m) modes. As a proof-of-concept, we compute waveforms for q=1/10. We discuss applications of these techniques for LIGO and VIRGO data analysis and the possibility that our technique can be extended to produce accurate waveform templates from a modest number of fully nonlinear numerical simulations.

  7. A new type of nonsingular black-hole solution in general relativity

    NASA Astrophysics Data System (ADS)

    Klinkhamer, F. R.

    2014-05-01

    Certain exact solutions of the Einstein field equations over nonsimply-connected manifolds are reviewed. These solutions are spherically symmetric and have no curvature singularity. They provide a regularization of the standard Schwarzschild solution with a curvature singularity at the center. Spherically symmetric collapse of matter in ℝ4 may result in these nonsingular black-hole solutions, if quantum-gravity effects allow for topology change near the center or if nontrivial topology is already present as a remnant from a quantum spacetime foam.

  8. Relative Content of Black Carbon in Submicron Aerosol as a Sign of the Effect of Forest Fire Smokes

    SciTech Connect

    Kozlov, V.S.; Panchenko, M.V.; Yauscheva, E.P.

    2005-03-18

    Biomass burning occurs often in regions containing vast forest tracts and peat-bogs. These processes are accompanied by the emission of a large amount of aerosol particles and crystal carbon (black carbon [BC], soot). BC is the predominant source of solar absorption in atmospheric aerosol, which impacts climate. (Jacobson 2001; Rozenberg 1982). In this paper, we analyze the results of laboratory and field investigations that focused on the relative content of BC in aerosol particles. Main attention is given to the study of possibility using this parameter as an informative sign for estimating the effect of remote forest fire smokes on the near-ground aerosol composition.

  9. Serum immune-related proteins are differentially expressed during hibernation in the American black bear.

    PubMed

    Chow, Brian A; Donahue, Seth W; Vaughan, Michael R; McConkey, Brendan; Vijayan, Mathilakath M

    2013-01-01

    Hibernation is an adaptation to conserve energy in the face of extreme environmental conditions and low food availability that has risen in several animal phyla. This phenomenon is characterized by reduced metabolic rate (∼25% of the active basal metabolic rate in hibernating bears) and energy demand, while other physiological adjustments are far from clear. The profiling of the serum proteome of the American black bear (Ursus americanus) may reveal specific proteins that are differentially modulated by hibernation, and provide insight into the remarkable physiological adaptations that characterize ursid hibernation. In this study, we used differential gel electrophoresis (DIGE) analysis, liquid chromatography coupled to tandem mass spectrometry, and subsequent MASCOT analysis of the mass spectra to identify candidate proteins that are differentially expressed during hibernation in captive black bears. Seventy serum proteins were identified as changing by ±1.5 fold or more, out of which 34 proteins increased expression during hibernation. The majority of identified proteins are involved in immune system processes. These included α2-macroglobulin, complement components C1s and C4, immunoglobulin μ and J chains, clusterin, haptoglobin, C4b binding protein, kininogen 1, α2-HS-glycoprotein, and apoplipoproteins A-I and A-IV. Differential expression of a subset of these proteins identified by proteomic analysis was also confirmed by immunodetection. We propose that the observed serum protein changes contribute to the maintenance of the hibernation phenotype and health, including increased capacities for bone maintenance and wound healing during hibernation in bears.

  10. The adrenocorical stress-response of Black-legged Kittiwake chicks in relation to dietary restrictions

    USGS Publications Warehouse

    Kitaysky, A.S.; Piatt, John F.; Wingfield, J.C.; Romano, M.

    1999-01-01

    In this study we examined hormonal responses of Black-legged Kittiwake (Rissa tridactyla) chicks to experimental variations in energy content and nutritional quality (low or high lipid to protein ratio, LPR) of their food. Starting at the age of 10 days, chicks were fed either high or low LPR fish at 30, 50, 70 and 100% of ad libitum energy intake. After 20 days of treatment, chicks were exposed to a standardized acute handling and restraint stress protocol, where a baseline sample was taken immediately after taking a chick from the nest, and three additional blood samples were taken at intervals up to 50 min. Testosterone and corticosterone titres in plasma were measured via radioimmunoassay. We found that baseline testosterone levels were not significantly affected by the experimental treatments. Food-restricted chicks had elevated baseline and acute stress-induced levels of corticosterone compared to chicks fed ad libitum. An elevation of circulating levels of corticosterone in energetically stressed individuals was further magnified by low nutritional quality of food. Baseline and acute stress-induced corticosterone levels of chicks were negatively correlated with their fat reserves. We conclude that the physiological condition of Black-legged Kittiwake chicks can be assessed reliably by measuring circulating levels of corticosterone. We discuss short- and long-term effects of elevated corticosterone secretion in food-stressed nest-bound chicks.

  11. The adrenocortical stress-response of Black-legged Kittiwake chicks in relation to dietary restrictions

    USGS Publications Warehouse

    Kitaysky, A.S.; Piatt, J.F.; Wingfield, J.C.; Romano, M.

    1999-01-01

    In this study we examined hormonal responses of Black-legged Kittiwake (Rissa tridactyla) chicks to experimental variations in energy content and nutritional quality (low or high lipid to protein ratio, LPR) of their food. Starting at the age of 10 days, chicks were fed either high or low LPR fish at 30, 50, 70 and 100% of ad libitum energy intake. After 20 days of treatment, chicks were exposed to a standardized acute handling and restraint stress protocol, where a baseline sample was taken immediately after taking a chick from the nest, and three additional blood samples were taken at intervals up to 50 min. Testosterone and corticosterone titres in plasma were measured via radioimmunoassay. We found that baseline testosterone levels were not significantly affected by the experimental treatments. Food-restricted chicks had elevated baseline and acute stress-induced levels of corticosterone compared to chicks fed ad libitum. An elevation of circulating levels of corticosterone in energetically stressed individuals was further magnified by low nutritional quality of food. Baseline and acute stress-induced corticosterone levels of chicks were negatively correlated with their fat reserves. We conclude that the physiological condition of Black-legged Kittiwake chicks can be assessed reliably by measuring circulating levels of corticosterone. We discuss short-and long-term effects of elevated corticosterone secretion in food-stressed nest-bound chicks.

  12. High Energy Plasmas, General Relativity and Collective Modes in the Vicinity of Black Holes*

    NASA Astrophysics Data System (ADS)

    Coppi, B.

    2009-05-01

    Plasmas around black holes can take different equilibrium configurations^1 from those known from fluid theory as the vertical Lorentz compression due to plasma currents can overtake that of the gravitational force. In a disk with a ``seed'' magnetic field, axisymmetric modes as well as tri-dimensional spirals can be excited by the combined effects of the radial gradient of the plasma rotation frequency and of the plasma pressure gradient^2. The spirals' properties depend strongly on their vertical structure^3. Axisymmetric modes can produce vertical counter-flows of thermal energy and particles and be candidates for the origin of the winds emanating from disks in Active Galactic Nuclei (AGN's)^2. The excitation of radially localized density spirals corotating with the plasma near a black hole can provide an explanation for^4 the observed Quasi Periodic Oscillations (QPO's) of the X-ray emission from compact objects. Convective spiral modes^3 that are purely oscillatory in time and not localized radially can acquire their amplitudes from coupling to unstable modes and provide transport^3 of angular momentum toward the outer region of the disk structure.*Sponsored in part by the U.S. DOE. ^1B. Coppi and F. Rousseau, Ap. J., 641, 458 (2006). ^2B. Coppi, Europhys. Letters 82, 19001 (2008). ^3B. Coppi, MIT/LNS Report 08/08, submitted to A&A (2008). ^4B. Coppi and P. Rebusco, Paper P5.154, E.P.S. Conf. Pl. Phys. (Crete, 2008).

  13. A note on black-hole physics, cosmic censorship, and the charge-mass relation of atomic nuclei

    NASA Astrophysics Data System (ADS)

    Hod, Shahar

    2016-02-01

    Arguing from the cosmic censorship principle, one of the fundamental cornerstones of black-hole physics, we have recently suggested the existence of a universal upper bound relating the maximal electric charge of a weakly self-gravitating system to its total mass: Z(A)≤slant {Z}*(A)\\equiv {α }-1/3{A}2/3, where Z is the number of protons in the system, A is the total baryon (mass) number, and α ={e}2/{{\\hslash }}c is the dimensionless fine-structure constant. In order to test the validity of this suggested bound, we here explore the Z(A) functional relation of atomic nuclei as deduced from the Weizsäcker semi-empirical mass formula. It is shown that all atomic nuclei, including the meta-stable maximally charged ones, conform to the suggested charge-mass upper bound. Our results support the validity of the cosmic censorship conjecture in black-hole physics.

  14. The Megamaser Cosmology Project: precise black hole mass measurement and the implication for the M BH-σ* relation

    NASA Astrophysics Data System (ADS)

    Kuo, Cheng-Yu; Braatz, James A.; Condon, James J.; Impellizzeri, Caterina M. V.; Lo, Kwok-Yung; Zaw, Ingyin; Henkel, Christian; Reid, Mark J.; Greene, Jenny E.; Gao, Feng; Zhao, Wei

    2016-02-01

    We made dynamical black hole mass measurements from nineteen Seyfert 2 galaxies which host sub-parsec H2O maser disks using the H2O megamaser technique. The nearly perfect Keplerian rotation curves in many of these maser systems guarantee the high accuracy and precision of the black hole mass measurements. With the stellar velocity dispersion (σ*) of the galaxy bulges measured with the Dupont 2.5 m telescope at Las Campanas Observatory in the South and the Apache Point Observatory (APO) 3.5m telescope in the North, we found that H2O maser galaxies, most of which host pseudo bulges rather than classical bulges, do not all follow the M BH -σ* relation shown in the literature. This result is well consistent with the latest findings by Kormendy & Ho (2013) that only early type galaxies and galaxies with classical bulges follow a tight MBH-σ* relation. Such a tight correlation may not exist in pseudo bulge galaxies.

  15. Labor market segmentation and relative black/white teenage birth rates.

    PubMed

    Mccrate, E

    1990-01-01

    "Teenage mothers typically have lower educational attainment than other women. Most observers have argued that this is a major reason for their greater risk of poverty. This article takes the opposite view: that circumstances associated with poverty contribute to a greater likelihood of teenage childbearing. In particular, poor educational quality and the chances of secondary sector employment are more common for black women, regardless of their age at first birth. Hence the payoffs to education may be quite low for these women, which may be the reason for early motherhood. This argument is presented in terms of segmented labor market theory. Data to support it is presented from the [U.S.] National Longitudinal Survey of Youth. Other common explanations of teenage motherhood are critiqued."

  16. Historical emissions of black and organic carbon aerosol from energy-related combustion, 1850-2000 - article no. GB2018

    SciTech Connect

    Bond, T.C.; Bhardwaj, E.; Dong, R.; Jogani, R.; Jung, S.K.; Roden, C.; Streets, D.G.; Trautmann, N.M.

    2007-05-15

    We present an emission inventory of primary black carbon (BC) and primary organic carbon (OC) aerosols from fossil fuel and biofuel combustion between 1850 and 2000. We reconstruct fossil fuel consumption and represent changes in technology on a national and sectoral basis. Our estimates rely on new estimates of biofuel consumption, and updated emission factors for old technologies. Emissions of black carbon increase almost linearly, totaling about 1000 Gg in 1850, 2200 Gg in 1900, 3000 Gg in 1950, and 4400 Gg in 2000. Primary organic carbon shows a similar pattern, with emissions of 4100 Gg, 5800 Gg, 6700 Gg, and 8700 Gg in 1850, 1900, 1950, and 2000, respectively. Biofuel is responsible for over half of BC emission until about 1890, and dominates energy-related primary OC emission throughout the entire period. Coal contributes the greatest fraction of BC emission between 1880 and 1975, and is overtaken by emissions from biofuel around 1975, and by diesel engines around 1990. Previous work suggests a rapid rise in BC emissions between 1950 and 2000. This work supports a more gradual increase between 1950 and 2000, similar to the increase between 1850 and 1925; implementation of clean technology is a primary reason.

  17. Leukocyte Telomere Length in Healthy White and Black Adolescents: Relations to Race, Sex, Adiposity, Adipokines and Physical Activity

    PubMed Central

    Zhu, Haidong; Wang, Xiaoling; Gutin, Bernard; Davis, Catherine L.; Keeton, Daniel; Thomas, Jeffrey; Stallmann-Jorgensen, Inger; Mooken, Grace; Bundy, Vanessa; Snieder, Harold; van der Harst, Pim; Dong, Yanbin

    2010-01-01

    Objectives To examine the relations of race, sex, adiposity, adipokines and physical activity to telomere length in adolescents. Study design Leukocyte telomere length (T/S ratio) was assessed cross-sectionally in 667 adolescents (aged 14–18 years, 48% blacks, 51% girls) using a quantitative PCR method. Generalized Estimating Equations analyses were performed. Results Black adolescents had longer telomeres than white adolescents (age and sex adjusted T/S ratio ± SE: 1.32 ± 0.01 vs. 1.27 ± 0.01, p=0.014) and girls had longer telomeres than boys (age and race adjusted T/S ratio ± SE: 1.31 ± 0.01 vs. 1.27 ± 0.01, p=0.007). None of the adiposity or adipokine measures explained a significant proportion of the variance in telomere length. Vigorous physical activity was positively associated with telomere length (adjusted R2=0.019, p=0.009) and accounted for 1.9% of the total variance only in girls. Conclusion This study, conducted in a biracial adolescent cohort, demonstrated that: (1) race and sex differences in telomere length have already emerged during adolescence; (2) adiposity and adipokines are not associated with telomere length at this age; and (3) the anti-aging effect of vigorous physical activity may begin in youth especially in girls. PMID:20855079

  18. Comparing Black hole Shadow Widths in the Equatorial Plane for General Relativity and Selected Alternative Theories of Gravity

    NASA Astrophysics Data System (ADS)

    Graber, James

    2017-01-01

    Results from ongoing efforts to measure the black hole shadows expected from Sgr A* and M87, e.g. by the Event-Horizon Telescope, could soon confirm or refute the Kerr nature of the black-hole shadow, thereby helping confirm or refute General Relativity. It is fairly easy to precisely calculate the width of the shadow of a compact, cylindrically symmetric rotating object in its equatorial plane. We have calculated these shadow widths for three different metrics: 1) the standard Kerr metric, 2) a rotating perturbed Kerr object with a quadrupole moment similar to a neutron star's, as computed by Frutos-Alfaro based on the earlier Manko et al. neutron-star metric, and 3) also for a new rotating metric based on the Yilmaz exponential metric. For reasonable (plausible) parameter values, the differences in calculated shadow widths are of the order of ten percent, which may be difficult to measure. We graphically present comparisons between the expected Kerr value for the shadow width, and the widths computed for the alternative metrics as a numerically computed function of the rotation and the quadrupole moment. If time allows, we may present similar calculations and graphs for the shadow widths of rotating compact objects from other alternative theories of gravity.

  19. Development of the black soldier fly (Diptera: Stratiomyidae) in relation to temperature.

    PubMed

    Tomberlin, Jeffery K; Adler, Peter H; Myers, Heidi M

    2009-06-01

    The black soldier fly, Hermetia illucens L., was reared on a grain-based diet at 27, 30, and 36 degrees C. Survival of 4- to 6-d-old larvae to adults averaged 74-97% at 27 and 30 degrees C but was only 0.1% at 36 degrees C. Flies required a mean of approximately 4 d (11%) longer to complete larval and pupal development at 27 degrees C than at 30 degrees C. At 27 and 30 degrees C, females weighed an average of 17-19% more than males but required an average of 0.6-0.8 d (3.0-4.3%) longer to complete larval development. At both temperatures, adult females lived an average of approximately 3.5 d less than adult males. The duration of larval development was a significant predictor of adult longevity. Temperature differences of even 3 degrees C produce significant fitness tradeoffs for males and females, influencing life history attributes and having practical applications for forensic entomology.

  20. Black Talk and Black Education

    ERIC Educational Resources Information Center

    Abrahams, Roger D.

    1969-01-01

    Demonstrates the need for cultural relativity in avoiding stereotyped reactions to the language of the lower-class black child. Appears in "The Florida FL Reporter special anthology issue, "Linguistic-Cultural Differences and American Education. The central portion of this essay is part of the opening argument of the author's forthcoming book…

  1. Black raspberries suppress colonic adenoma development in ApcMin/+ mice: relation to metabolite profiles.

    PubMed

    Pan, Pan; Skaer, Chad W; Wang, Hsin-Tzu; Stirdivant, Steven M; Young, Matthew R; Oshima, Kiyoko; Stoner, Gary D; Lechner, John F; Huang, Yi-Wen; Wang, Li-Shu

    2015-10-01

    Freeze-dried black raspberries (BRBs) have demonstrated chemopreventive effects in a dietary intervention trial with human colorectal cancer patients. The aim of this study was to investigate BRB-caused metabolite changes using the Apc(Min/+) mouse as a model of human colorectal cancer. Wild-type (WT) mice were fed control diet, and Apc(Min/+) mice were fed either control diet or control diet supplemented with 5% BRBs for 8 weeks. Colonic and intestinal polyp size and number were measured. A non-targeted metabolomic analysis was conducted on colonic mucosa, liver and fecal specimens. Eight weeks of BRB treatment significantly decreased intestinal and colonic polyp number and size in Apc(Min/+) mice. The apc gene mutation significantly changed 52 metabolites in colonic mucosa associated with increased amino acid and decreased lipid metabolites, as well as 39 liver and 8 fecal metabolites. BRBs significantly reversed 23 apc-regulated metabolites, including 13 colonic mucosa, 8 liver and 2 fecal metabolites that were involved in amino acid, glutathione, lipid and nucleotide metabolism. Of these, changes in eight metabolites were linearly correlated with decreased colonic polyp number and size in BRB-treated Apc(Min/+) mice. Elevated levels of putrescine and linolenate in Apc(Min/+) mice were significantly decreased by BRBs. Ornithine decarboxylase expression, the key enzyme in putrescine generation, was fully suppressed by BRBs. These results suggest that BRBs produced beneficial effects against colonic adenoma development in Apc(Min/+) mice and modulated multiple metabolic pathways. The metabolite changes produced by BRBs might potentially reflect the BRB-mediated chemopreventive effects in colorectal cancer patients.

  2. Racial and Ethnic-Related Stressors as Predictors of Perceived Stress and Academic Performance for African American Students at a Historically Black College and University

    ERIC Educational Resources Information Center

    Greer, Tawanda M.

    2008-01-01

    The purpose of this investigation was to determine whether racial and ethnic-related stressors were associated with overall levels of perceived stress and academic performance among African American students at a historically Black college and university (HBCU). Hierarchical regression analyses were used to test racial and ethnic-related stressors…

  3. Black hole hair removal

    NASA Astrophysics Data System (ADS)

    Banerjee, Nabamita; Mandal, Ipsita; Sen, Ashoke

    2009-07-01

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

  4. Microlensing of Sub-parsec Massive Binary Black Holes in Lensed QSOs: Light Curves and Size-Wavelength Relation

    NASA Astrophysics Data System (ADS)

    Yan, Chang-Shuo; Lu, Youjun; Yu, Qingjuan; Mao, Shude; Wambsganss, Joachim

    2014-04-01

    Sub-parsec binary massive black holes (BBHs) have long been thought to exist in many QSOs but remain observationally elusive. In this paper, we propose a novel method to probe sub-parsec BBHs through microlensing of lensed QSOs. If a QSO hosts a sub-parsec BBH in its center, it is expected that the BBH is surrounded by a circumbinary disk, each component of the BBH is surrounded by a small accretion disk, and a gap is opened by the secondary component in between the circumbinary disk and the two small disks. Assuming such a BBH structure, we generate mock microlensing light curves for some QSO systems that host BBHs with typical physical parameters. We show that microlensing light curves of a BBH QSO system at the infrared-optical-UV bands can be significantly different from those of corresponding QSO system with a single massive black hole (MBH), mainly because of the existence of the gap and the rotation of the BBH (and its associated small disks) around the center of mass. We estimate the half-light radii of the emission region at different wavelengths from mock light curves and find that the obtained half-light radius versus wavelength relations of BBH QSO systems can be much flatter than those of single MBH QSO systems at a wavelength range determined by the BBH parameters, such as the total mass, mass ratio, separation, accretion rates, etc. The difference is primarily due to the existence of the gap. Such unique features on the light curves and half-light radius-wavelength relations of BBH QSO systems can be used to select and probe sub-parsec BBHs in a large number of lensed QSOs to be discovered by current and future surveys, including the Panoramic Survey Telescope and Rapid Response System, the Large Synoptic Survey telescope, and Euclid.

  5. THE L{proportional_to}{sigma}{sup 8} CORRELATION FOR ELLIPTICAL GALAXIES WITH CORES: RELATION WITH BLACK HOLE MASS

    SciTech Connect

    Kormendy, John; Bender, Ralf E-mail: bender@mpe.mpg.de

    2013-05-20

    We construct the Faber-Jackson correlation between velocity dispersion {sigma} and total galaxy luminosity L{sub V} separately for elliptical galaxies with and without cores. The coreless ellipticals show the well-known, steep relationship dlog {sigma}/dlog L{sub V} = 0.268 or L{sub V} {proportional_to}{sigma}{sup 3.74}. This corresponds to dlog {sigma}/dlog M = 0.203, where M is the stellar mass and we use M/L{proportional_to}L {sup 0.32}. In contrast, the velocity dispersions of core ellipticals increase much more slowly with L{sub V} and M: dlog {sigma}/dlog L{sub V} = 0.120, L{sub V} {proportional_to}{sigma}{sup 8.33}, and dlog {sigma}/dlog M = 0.091. Dissipationless major galaxy mergers are expected to preserve {sigma} according to the simplest virial-theorem arguments. However, numerical simulations show that {sigma} increases slowly in dry major mergers, with dlog {sigma}/dlog M {approx_equal} +0.15. In contrast, minor mergers cause {sigma} to decrease, with dlog {sigma}/dlog M {approx_equal} -0.05. Thus, the observed relation argues for dry major mergers as the dominant growth mode of the most massive ellipticals. This is consistent with what we know about the formation of cores. We know no viable way to explain galaxy cores except through dissipationless mergers of approximately equal-mass galaxies followed by core scouring by binary supermassive black holes. The observed, shallow {sigma}{proportional_to}L{sub V}{sup +0.12} relation for core ellipticals provides further evidence that they formed in dissipationless and predominantly major mergers. Also, it explains the observation that the correlation of supermassive black hole mass with velocity dispersion, M{sub .}{proportional_to}{sigma}{sup 4}, ''saturates'' at high M{sub .} such that M{sub .} becomes almost independent of {sigma}.

  6. Microlensing of sub-parsec massive binary black holes in lensed QSOs: Light curves and size-wavelength relation

    SciTech Connect

    Yan, Chang-Shuo; Lu, Youjun; Mao, Shude; Yu, Qingjuan; Wambsganss, Joachim E-mail: luyj@nao.cas.cn

    2014-04-01

    Sub-parsec binary massive black holes (BBHs) have long been thought to exist in many QSOs but remain observationally elusive. In this paper, we propose a novel method to probe sub-parsec BBHs through microlensing of lensed QSOs. If a QSO hosts a sub-parsec BBH in its center, it is expected that the BBH is surrounded by a circumbinary disk, each component of the BBH is surrounded by a small accretion disk, and a gap is opened by the secondary component in between the circumbinary disk and the two small disks. Assuming such a BBH structure, we generate mock microlensing light curves for some QSO systems that host BBHs with typical physical parameters. We show that microlensing light curves of a BBH QSO system at the infrared-optical-UV bands can be significantly different from those of corresponding QSO system with a single massive black hole (MBH), mainly because of the existence of the gap and the rotation of the BBH (and its associated small disks) around the center of mass. We estimate the half-light radii of the emission region at different wavelengths from mock light curves and find that the obtained half-light radius versus wavelength relations of BBH QSO systems can be much flatter than those of single MBH QSO systems at a wavelength range determined by the BBH parameters, such as the total mass, mass ratio, separation, accretion rates, etc. The difference is primarily due to the existence of the gap. Such unique features on the light curves and half-light radius-wavelength relations of BBH QSO systems can be used to select and probe sub-parsec BBHs in a large number of lensed QSOs to be discovered by current and future surveys, including the Panoramic Survey Telescope and Rapid Response System, the Large Synoptic Survey telescope, and Euclid.

  7. The stress of being contaminated? Adrenocortical function and reproduction in relation to persistent organic pollutants in female black legged kittiwakes.

    PubMed

    Tartu, Sabrina; Angelier, Frédéric; Herzke, Dorte; Moe, Børge; Bech, Claus; Gabrielsen, Geir W; Bustnes, Jan Ove; Chastel, Olivier

    2014-04-01

    High levels of environmental pollutants such as persistent organic pollutants (POPs) including PCB and DDT have been found in the Arctic and many of those pollutants may impair reproduction through endocrine disruption. Nevertheless, their effects on stress hormones remain poorly understood, especially in free-ranging birds. Corticosterone, the principal glucocorticoid in birds, can indirectly impair reproduction. The aim of the present study was to examine the relationships between POPs and reproduction through their potential consequences on different reproductive traits (breeding decision, egg-laying date, breeding success) and corticosterone secretion (baseline and stress-induced levels). We addressed those questions in an Arctic population of female black-legged kittiwakes during the pre-breeding stage and measured several legacy POPs (PCBs and pesticides: HCB, p,p'-DDE, CHL) in whole blood. POP levels were not related to breeding decision neither to breeding success, whereas females with high levels of pesticides laid their eggs earlier in the season. We found a negative relationship between POP levels and body condition index in non-breeding females. Black-legged kittiwakes with higher levels of PCB showed stronger adrenocortical response when subjected to a capture-handling stress protocol. We suggest that PCBs may disrupt corticosterone secretion whereas the positive relationship between pesticides and egg-laying date could either originate from a direct effect of pesticides or may be related to other confounding factors such as age or individual's quality. Although no direct negative reproduction output of POPs was found in this study, it is possible that the most contaminated individuals would be more sensitive to environmental stress and would be less able to maintain parental investment than less polluted individuals.

  8. Holocene sea level and climate change in the Black Sea: Multiple marine incursions related to freshwater discharge events

    USGS Publications Warehouse

    Martin, R.E.; Leorri, E.; McLaughlin, P.P.

    2007-01-01

    Repeated marine invasions of the Black Sea during the Holocene have been inferred by many eastern scientists as resulting from episodes of marine inflow from the Mediterranean beneath a brackish outflow from the Black Sea. We support this scenario but a fundamental question remains: What caused the repeated marine invasions? We offer an hypothesis for the repeated marine invasions of the Black Sea based on: (1) the overall similarity of sea-level curves from both tectonically quiescent and active margins of the Black Sea and their similarity to a sequence stratigraphic record from the US mid-Atlantic coast. The similarity of the records from two widely-separated regions suggests their common response to documented Holocene climate ocean-atmosphere reorganizations (coolings); (2) the fact that in the modern Black Sea, freshwater runoff from surrounding rivers dominates over evaporation, so that excess runoff might have temporarily raised Black Sea level (although the Black Sea would have remained brackish). Following the initial invasion of the Black Sea by marine Mediterranean waters (through the Marmara Sea) in the early Holocene, repeated marine incursions were modulated, or perhaps even caused, by freshwater discharge to the Black Sea. Climatic amelioration (warming) following each documented ocean-atmosphere reorganization during the Holocene likely shifted precipitation patterns in the surrounding region and caused mountain glaciers to retreat, increasing freshwater runoff above modern values and temporarily contributing to an increase of Black Sea level. Freshwater-to-brackish water discharges into the Black Sea initially slowed marine inflow but upon mixing of runoff with more marine waters beneath them and their eventual exit through the Bosphorus, marine inflow increased again, accounting for the repeated marine invasions. The magnitude of the hydrologic and sea-level fluctuations became increasingly attenuated through the Holocene, as reflected by Black

  9. The Relation between Globular Cluster Systems and Supermassive Black Holes in Spiral Galaxies: The Case Study of NGC 4258

    NASA Astrophysics Data System (ADS)

    González-Lópezlira, Rosa A.; Lomelí-Núñez, Luis; Álamo-Martínez, Karla; Órdenes-Briceño, Yasna; Loinard, Laurent; Georgiev, Iskren Y.; Muñoz, Roberto P.; Puzia, Thomas H.; Bruzual A., Gustavo; Gwyn, Stephen

    2017-02-01

    We aim to explore the relationship between globular cluster total number, {N}{GC}, and central black hole mass, M •, in spiral galaxies, and compare it with that recently reported for ellipticals. We present results for the Sbc galaxy NGC 4258, from Canada–France–Hawaii Telescope data. Thanks to water masers with Keplerian rotation in a circumnuclear disk, NGC 4258 has the most precisely measured extragalactic distance and supermassive black hole mass to date. The globular cluster (GC) candidate selection is based on the ({u}* -{i}\\prime ) versus ({i}\\prime -{K}s) diagram, which is a superb tool to distinguish GCs from foreground stars, background galaxies, and young stellar clusters, and hence can provide the best number counts of GCs from photometry alone, virtually free of contamination, even if the galaxy is not completely edge-on. The mean optical and optical-near-infrared colors of the clusters are consistent with those of the Milky Way and M 31, after extinction is taken into account. We directly identify 39 GC candidates; after completeness correction, GC luminosity function extrapolation, and correction for spatial coverage, we calculate a total {N}{GC}=144+/- {31}-36+38 (random and systematic uncertainties, respectively). We have thus increased to six the sample of spiral galaxies with measurements of both M • and {N}{GC}. NGC 4258 has a specific frequency {S}{{N}}=0.4+/- 0.1 (random uncertainty), and is consistent within 2σ with the {N}{GC} versus M • correlation followed by elliptical galaxies. The Milky Way continues to be the only spiral that deviates significantly from the relation.

  10. The Local Black Hole Mass Function Derived from the MBH-P and the MBH-n Relations

    NASA Astrophysics Data System (ADS)

    Mutlu-Pakdil, Burçin; Seigar, Marc S.; Davis, Benjamin L.

    2016-10-01

    We present a determination of the supermassive black hole (SMBH) mass function for early- and late-type galaxies in the nearby universe (z < 0.0057), established from a volume-limited sample consisting of a statistically complete collection of the brightest spiral galaxies in the southern hemisphere. The sample is defined by limiting luminosity (redshift-independent) distance, D L = 25.4 Mpc, and a limiting absolute B-band magnitude, {{M}}B=-19.12. These limits define a sample of 140 spiral, 30 elliptical (E), and 38 lenticular (S0) galaxies. We established the Sérsic index distribution for early-type (E/S0) galaxies in our sample. Davis et al. established the pitch angle distribution for their sample, which is identical to our late-type (spiral) galaxy sample. We then used the pitch angle and the Sérsic index distributions in order to estimate the SMBH mass function for our volume-limited sample. The observational simplicity of our approach relies on the empirical relation between the mass of the central SMBH and the Sérsic index for an early-type galaxy or the logarithmic spiral-arm pitch angle for a spiral galaxy. Our SMBH mass function agrees well at the high-mass end with previous values in the literature. At the low-mass end, although inconsistencies exist in previous works that still need to be resolved, our work is more in line with expectations based on modeling of black hole evolution.

  11. Vocal repertoire of free-ranging black howler monkeys' (Alouatta pigra): Call types, contexts, and sex-related contributions.

    PubMed

    Briseño-Jaramillo, Margarita; Biquand, Véronique; Estrada, Alejandro; Lemasson, Alban

    2017-01-17

    Alouatta species utter the most powerful primate vocalizations in the Neotropics and are well-known for their loud and long-lasting male howling bouts. However, the diversity of acoustic structures used in these howling bouts, as well as in non-howling contexts, and the relative contribution of the different group members to the entire vocal repertoire, needed to be explored further. This report provides the first detailed description of the vocal repertoire of black howler monkeys (Alouatta pigra), focusing on acoustic structures and contexts of emission of both loud and soft calls as well as on the contribution rate of males and females to the different call types. Three free-ranging social groups of black howler monkeys living in Palenque National Park, Mexico were monitored. We identified twelve acoustically discriminable call types, eight described previously and four described here for the first time. A few call types were systematically emitted either isolated or during howling bouts, but most of them could be heard in both calling contexts. Three call types were emitted only by females and two only by males. Adult males' call rates (for the seven shared call types) were higher than those of females but only when considering calls emitted within howling bouts. Our contextual analysis enabled us to divide call types into potential functional categories, according to their degree of contribution, to intra-group versus inter-group interactions and to neutral-positive versus negative situations. We then discussed how socio-ecological factors, notably sex differences in social behaviors, may explain the variability found in the vocal repertoire of this species and compared our findings with the literature on other primate species.

  12. The M {sub BH} versus M {sub G}σ{sup 2} relation and the accretion of supermassive black holes

    SciTech Connect

    Feoli, A.

    2014-03-20

    We propose a possible scenario that can explain the physical processes underlying the relation log{sub 10}(M {sub BH}) = b + mlog{sub 10}(M {sub G}σ{sup 2}/c {sup 2}) between the mass M {sub BH} of supermassive black holes, growing in the center of many galaxies, and the kinetic energy of the corresponding bulges (M {sub G} being the bulge mass and σ the velocity dispersion). In a series of papers, this scaling law proved to be very useful to describe the evolution of galaxies thanks to its close similarity to the Hertzsprung-Russell diagram. Studying the relation with different samples of galaxies, we have generally found a slope that can vary between two extremal theoretical possibilities, m = 3/4 and m = 1. We will try to describe a possible scenario compatible with the second one. Finally, we also examine a case of a relation that is linear, not in kinetic energy, but in momentum parameter.

  13. Sequestration of soil nitrogen as tannin-protein complexes may improve the competitive ability of sheep laurel (Kalmia angustifolia) relative to black spruce (Picea mariana).

    PubMed

    Joanisse, G D; Bradley, R L; Preston, C M; Bending, G D

    2009-01-01

    The role of litter tannins in controlling soil nitrogen (N) cycling may explain the competitive ability of Kalmia relative to black spruce (Picea mariana), although this has not been demonstrated experimentally. Here, the protein-precipitation capacities of purified tannins and leaf extracts from Kalmia and black spruce were compared. The resistance to degradation of tannin-protein precipitates from both species were compared by monitoring carbon (C) and N dynamics in humus amended with protein, purified tannins or protein-tannin precipitates. The purity of the precipitates was verified using solid-state (13)C nuclear magnetic resonance (NMR) spectra. The ability of mycorrhizal fungi associated with both species to grow on media amended with tannin-protein complexes as the principal N source was also compared. The protein precipitation capacity of Kalmia tannins was superior to those of black spruce. Humus amended with protein increased both mineral and microbial N, whereas humus amended with tannin-protein precipitates increased dissolved organic N. Mycorrhizal fungi associated with Kalmia showed better growth than those associated with black spruce when N was provided as tannin-protein precipitates. These data suggest that Kalmia litter increases the amount of soil N sequestered as tannin-protein complexes, which may improve the competitive ability of Kalmia relative to black spruce by favouring N uptake by mycorrhizas associated with the former.

  14. A Comprehensive Reevaluation of the Relation Between Black Hole Mass and Bulge Luminosity in Nearby Active Galaxies

    NASA Astrophysics Data System (ADS)

    Ho, Luis

    2010-09-01

    The scaling relations between black hole {BH} mass and bulge properties serve as powerful tools to study the interplay between BH growth and galaxy formation. The BH mass-bulge luminosity relation for galaxies hosting AGNs holds special promise because it can be more easily traced out to earlier epochs when both BH growth and star formation were more active. Recent studies suggest that at higher redshifts BH growth outpaced bulge assembly, but this potentially very important result critically depends on our knowledge of the local scaling relations, which are still poorly known. In an archival study approved for Cycle 15, we characterized, for the first time, the intrinsic scatter of the BH mass-bulge luminosity relation and its dependence on AGN properties for a sample of 45 local quasars containing the most massive BHs hosted by early-type galaxies. Our analysis employs a sophisticated new technique to decompose the two-dimensional structure of the host galaxies with unprecedented accuracy. Here we propose to extend our program to a large, comprehensive sample of 223 lower mass, lower luminosity AGNs at z < 0.35, most of which are hosted by disk galaxies. We will derive accurate photometric parameters for the bulge, taking into account, when necessary complex components such as bars, spiral arms, and nonaxisymmetric structures. We will use these measurements to reevaluate the slope, zero point, and scatter of the BH mass-bulge luminosity relation, and their possible dependence on AGN and host galaxy properties. Combined with our previous analysis, our study covers the largest possible dynamic range in BH mass, AGN luminosity, and host galaxy morphological type. It will serve as a fundamental reference point for all future investigations of the cosmic evolution of the BH-host scaling relations.

  15. Relational Teaching with Black Boys: Strategies for Learning at a Single-Sex Middle School for Boys of Color

    ERIC Educational Resources Information Center

    Nelson, Joseph Derrick

    2016-01-01

    Background/Context: Positive teacher-student relationships are critical for Black boys' learning across single-sex and coeducational environments. Limited attention to these relationships by school professionals is rooted in deficit-oriented conceptions of boyhood and Black masculinity. The popular message of deficiency and pathology is clear:…

  16. The Declining Relative Status of Black Women Workers, 1980-2002

    ERIC Educational Resources Information Center

    Dozier, Raine

    2010-01-01

    During the 1980s and 1990s, industrial restructuring led to a marked increase in wage inequality. Women, however, were not as negatively affected by declining manufacturing employment because their pay was relatively low within the industry, and their already high representation in the service sector provided access to newly created opportunities.…

  17. Black Sea mud volcanoes and their relation to the search for methane gas hydrates and environmental security

    NASA Astrophysics Data System (ADS)

    Shnyukov, Evgeny; Yanko-Hombach, Valentina; Motnenko, Irena

    2016-04-01

    As of today, the number of known offshore mud volcanoes in the Black Sea is 68. The areas possessing the greatest abundance include the northern part of the Black Sea (Sorokin trough, Tuapsinskaya trough, Shatskiy arch) and the Kerch downfold (the area south of the Kerch peninsula). An intensive study of mud volcanoes has been performed in the course of on-shore and off-shore expeditions carried out by Ukrainian scientists since 1990. They brought to light new geological, geophysical, and geochemical data on the properties of mud volcanoes by (1) high resolution hydro-acoustic, seismic-acoustic, and gravity methods, (2) geothermal observations of the thermal regime of the water and uppermost sediments, (3) gravity core sampling of bottom deposits, (4) dredges and buckets, and (5) study of these samples by lithological, geochemical, paleontological, and biological methods. Methane gas hydrates have been recovered in about 28 localities largely associated with mud volcanoes below 600-700 m water depth, which suggests their close genetic relationships. Age of the sediments hosting methane gas hydrates as well as their lithological properties (e.g., grain-size) vary significantly. Relatively coarse-grained sediments make better hydrate reservoirs than fine-grained sediments. The area of the Black Sea suitable for gas hydrate formation is estimated at 288,100 km2, representing about 68% of the total Black Sea, or almost 91% of the deep-water basin; the volume of gas hydrates has been set at 4.8 km3 corresponding to 0.1-11012 m3 of free methane. A peculiar morphological structure of the sea bottom - conical hills (anticlinals) with low geostatic pressure and subsidence in their central part - provide a target in the search for underwater mud volcanoes. Our data show that such structures are formed by mud breccia and rock debris that are brought to the surface by methane flows, which escape along tectonic ruptures from the deep part of the lithosphere located beneath a

  18. BOOK REVIEW Cracking the Einstein Code: Relativity and the Birth of Black Hole Physics With an Afterword by Roy Kerr Cracking the Einstein Code: Relativity and the Birth of Black Hole Physics With an Afterword by Roy Kerr

    NASA Astrophysics Data System (ADS)

    Carr, Bernard

    2011-02-01

    General relativity is arguably the most beautiful scientific theory ever conceived but its status within mainstream physics has vacillated since it was proposed in 1915. It began auspiciously with the successful explanation of the precession of Mercury and the dramatic confirmation of light-bending in the 1919 solar eclipse expedition, which turned Einstein into an overnight celebrity. Though little noticed at the time, there was also Karl Schwarzschild's discovery of the spherically symmetric solution in 1916 (later used to predict the existence of black holes) and Alexander Friedmann's discovery of the cosmological solution in 1922 (later confirmed by the discovery of the cosmic expansion). Then for 40 years the theory was more or less forgotten, partly because most physicists were turning their attention to the even more radical developments of quantum theory but also because the equations were too complicated to solve except in situations involving special symmetries or very weak gravitational fields (where general relativity is very similar to Newtonian theory). Furthermore, it was not clear that strong gravitational fields would ever arise in the real universe and, even if they did, it seemed unlikely that Einstein's equations could then be solved. So research in relativity became a quiet backwater as mainstream physics swept forward in other directions. Even Einstein lost interest, turning his attention to the search for a unified field theory. This book tells the remarkable story of how the tide changed in 1963, when the 28-year-old New Zealand mathematician Roy Kerr discovered an exact solution of Einstein's equations which represents a rotating black hole, thereby cracking the code of the title. The paper was just a few pages long, it being left for others to fill in the extensive beautiful mathematics which underlay the result, but it ushered in a golden age of relativity and is now one of the most cited works in physics. Coincidentally, Kerr

  19. Differences in substance use, psychosocial characteristics and HIV-related sexual risk behavior between Black men who have sex with men only (BMSMO) and Black men who have sex with men and women (BMSMW) in six US cities.

    PubMed

    Dyer, Typhanye P; Regan, Rotrease; Wilton, Leo; Harawa, Nina T; Ou, San San; Wang, Lei; Shoptaw, Steve

    2013-12-01

    We assessed associations in substance use, psychosocial characteristics, and HIV-related sexual risk behaviors, comparing characteristics of Black men who only have sex with other men only (BMSMO; n = 839) to Black men who have sex with men and women (BMSMW; n = 590). The study analyzed baseline data from the HIV Prevention Trials Network Brothers Study (HPTN 061), a feasibility study of a multi-component intervention for Black MSM in six US cities. Bivariate analyses compared BMSMO to BMSMW along demographics, substance use, psychosocial characteristics, and HIV-related sexual risk behaviors. Logistic regression models then assessed multivariable associations between being BMSMW and the odds of engaging in HIV-related sexual risk behaviors. Adjusted analyses revealed that BMSMW remained more likely to have unprotected anal intercourse while under the influence of alcohol (AOR: 1.45; 95 % CI:1.11-1.90) and were more likely to receive money/drugs for sex (AOR: 2.11; 95 % CI:1.48-3.03), compared to BMSMO. Substance use is an important factor to be considered when developing risk-reduction interventions for BMSMW. Structural interventions that address factors that may contribute to exchange sex among these men are also warranted.

  20. The Relation of Racial Identity, Ethnic Identity, and Racial Socialization to Discrimination-Distress: A Meta-Analysis of Black Americans

    ERIC Educational Resources Information Center

    Lee, Debbiesiu L.; Ahn, Soyeon

    2013-01-01

    This meta-analysis synthesized the results of 27 studies examining the relations of racial identity, ethnic identity, and racial socialization to discrimination-distress for Black Americans. The purpose was to uncover which constructs connected to racial identity, ethnic identity, and racial socialization most strongly correlate with racial…

  1. Limited Life Opportunities for Black and Latino Youth. Report on a Public Hearing by the Los Angeles County Commission on Human Relations (Compton, California, April 26, 1990).

    ERIC Educational Resources Information Center

    Los Angeles County Commission on Human Relations, CA.

    The Los Angeles County Commission on Human Relations held a public hearing to examine the effects of poverty on the hundreds of thousands of low income Blacks and Latinos under the age of 18 residing in Los Angeles County (California). The Commission's findings, recommendations, and concerns are presented. The following findings are presented: (1)…

  2. ON THE COSMIC EVOLUTION OF THE SCALING RELATIONS BETWEEN BLACK HOLES AND THEIR HOST GALAXIES: BROAD-LINE ACTIVE GALACTIC NUCLEI IN THE zCOSMOS SURVEY

    SciTech Connect

    Merloni, A.; Bongiorno, A.; Brusa, M.; Bolzonella, M.; Comastri, A.; Gilli, R.; Lusso, E.; Mignoli, M.; Civano, F.; Elvis, M.; Hao, H.; Fiore, F.; Jahnke, K.; Koekemoer, A. M.; Mainieri, V.; Miyaji, T.; Renzini, A.; Salvato, M.; Silverman, J.; Trump, J.

    2010-01-01

    We report on the measurement of the physical properties (rest-frame K-band luminosity and total stellar mass) of the hosts of 89 broad-line (type-1) active galactic nuclei (AGNs) detected in the zCOSMOS survey in the redshift range 1 < z < 2.2. The unprecedented multi-wavelength coverage of the survey field allows us to disentangle the emission of the host galaxy from that of the nuclear black hole in their spectral energy distributions (SEDs). We derive an estimate of black hole masses through the analysis of the broad Mg II emission lines observed in the medium-resolution spectra taken with VIMOS/VLT as part of the zCOSMOS project. We found that, as compared to the local value, the average black hole to host-galaxy mass ratio appears to evolve positively with redshift, with a best-fit evolution of the form (1+z){sup 0.68+}-{sup 0.12+0.6{sub -0.3}}, where the large asymmetric systematic errors stem from the uncertainties in the choice of initial mass function, in the calibration of the virial relation used to estimate BH masses and in the mean QSO SED adopted. On the other hand, if we consider the observed rest-frame K-band luminosity, objects tend to be brighter, for a given black hole mass, than those on the local M{sub BH}-M{sub K} relation. This fact, together with more indirect evidence from the SED fitting itself, suggests that the AGN hosts are likely actively star-forming galaxies. A thorough analysis of observational biases induced by intrinsic scatter in the scaling relations reinforces the conclusion that an evolution of the M{sub BH}-M{sub *} relation must ensue for actively growing black holes at early times: either its overall normalization, or its intrinsic scatter (or both) appear to increase with redshift. This can be interpreted as signature of either a more rapid growth of supermassive black holes at high redshift, a change of structural properties of AGN hosts at earlier times, or a significant mismatch between the typical growth times of

  3. How does thinking in Black and White terms relate to eating behavior and weight regain?

    PubMed

    Palascha, Aikaterini; van Kleef, Ellen; van Trijp, Hans C M

    2015-05-01

    This study explores the role of dichotomous thinking on eating behavior and its association with restraint eating and weight regain in a wide range of people. In a web-based survey with 241 adults, dichotomous thinking and behavioral outcomes related to eating (restraint eating, weight regain, body mass index, dieting) were assessed. Results showed that eating-specific dichotomous thinking (dichotomous beliefs about food and eating) mediates the association between restraint eating and weight regain. We conclude that holding dichotomous beliefs about food and eating may be linked to a rigid dietary restraint, which in turn impedes people's ability to maintain a healthy weight.

  4. Cystic Fibrosis Related Liver Disease—Another Black Box in Hepatology

    PubMed Central

    Staufer, Katharina; Halilbasic, Emina; Trauner, Michael; Kazemi-Shirazi, Lili

    2014-01-01

    Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments. PMID:25093717

  5. Cystic fibrosis related liver disease--another black box in hepatology.

    PubMed

    Staufer, Katharina; Halilbasic, Emina; Trauner, Michael; Kazemi-Shirazi, Lili

    2014-08-04

    Due to improved medical care, life expectancy in patients with cystic fibrosis (CF) has veritably improved over the last decades. Importantly, cystic fibrosis related liver disease (CFLD) has become one of the leading causes of morbidity and mortality in CF patients. However, CFLD might be largely underdiagnosed and diagnostic criteria need to be refined. The underlying pathomechanisms are largely unknown, and treatment strategies with proven efficacy are lacking. This review focuses on current invasive and non-invasive diagnostic standards, the current knowledge on the pathophysiology of CFLD, treatment strategies, and possible future developments.

  6. Shaping the relation between the mass of supermassive black holes and the velocity dispersion of galactic bulges

    NASA Astrophysics Data System (ADS)

    Chan, M. H.

    2013-05-01

    I use the fact that the radiation emitted by the accretion disk of supermassive black hole can heat up the surrounding gas in the protogalaxy to achieve hydrostatic equilibrium during the galaxy formation. The correlation between the black hole mass M BH and velocity dispersion σ thus naturally arises. The result generally agrees with empirical fittings from observational data, even with M BH ≤106 M ⊙. This model provides a clear picture on how the properties of the galactic supermassive black holes are connected with the kinetic properties of the galactic bulges.

  7. Physical mapping of black spot disease resistance/susceptibility-related genome regions in Japanese pear (Pyrus pyrifolia) by BAC-FISH.

    PubMed

    Yamamoto, Masashi; Terakami, Shingo; Takada, Norio; Yamamoto, Toshiya

    2016-06-01

    Black spot disease, caused by Alternaria alternata Japanese pear pathotype, is one of the most harmful diseases in Japanese pear cultivation. In the present study, the locations of black spot disease resistance/susceptibility-related genome regions were studied by fluorescence in situ hybridization using BAC clone (BAC-FISH) on Japanese pear (Pyrus pyrifolia (Burm. f.) Nakai) chromosomes. Root tips of self-pollinated seedlings of 'Osa Gold' were used as materials. Chromosome samples were prepared by the enzymatic maceration and air-drying method. The BAC clone adjacent to the black spot disease-related gene was labeled as a probe for FISH analysis. Black spot disease-related genome regions were detected in telomeric positions of two medium size chromosomes. These two sites and six telomeric 18S-5.8S-25S rDNA sites were located on different chromosomes as determined from the results of multi-color FISH. The effectiveness of the physical mapping of useful genes on pear chromosomes achieved by the BAC-FISH method was unequivocally demonstrated.

  8. The Origin of the Intrinsic Scatter in the Relation Between Black Hole Mass and Bulge Luminosity for Nearby Active Galaxies

    NASA Astrophysics Data System (ADS)

    Kim, Minjin; Ho, Luis C.; Peng, Chien Y.; Barth, Aaron J.; Im, Myungshin; Martini, Paul; Nelson, Charles H.

    2008-11-01

    We investigate the origin of the intrinsic scatter in the correlation between black hole mass (MBH) and bulge luminosity (Lbul) in a sample of 45 massive, local (zlesssim 0.35) type 1 active galactic nuclei (AGNs). We derive MBH from published optical spectra assuming a spherical broad-line region, and Lbul from detailed two-dimensional decomposition of archival optical Hubble Space Telescope images. AGNs follow the MBH - Lbul relation of inactive galaxies, but the zero point is shifted by an average of Δ log MBH ≈ - 0.3 dex. We show that the magnitude of the zero point offset, which is responsible for the intrinsic scatter in the MBH - Lbul relation, is correlated with several AGN and host galaxy properties, all of which are ultimately related to, or directly impact, the BH mass accretion rate. At a given bulge luminosity, sources with higher Eddington ratios have lower MBH. The zero point offset can be explained by a change in the normalization of the virial product used to estimate MBH, in conjunction with modest BH growth (~10%-40%) during the AGN phase. Galaxy mergers and tidal interactions appear to play an important role in regulating AGN fueling in low-redshift AGNs. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Data Archive at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555. These observations are associated with program AR-10969 and GO-9763.

  9. Reproduction of black-crowned night-herons related to predation and contaminants in Oregon and Washington, USA

    USGS Publications Warehouse

    Blus, L.J.; Rattner, B.A.; Melancon, M.J.; Henny, C.J.

    1997-01-01

    We studied reproductive characteristics of Black-crowned Night-Herons (Nycticorax nycticorax) at four colonies in south central Washington and one colony in north central Oregon in 1991. Nest success, adjusted using the Mayfield method, was significantly different between colonies and ranged from 12-84% to hatching and 12-73% to 14 days post-hatching. The mean number of young surviving to 14 days of age in each colony ranged from 0.47-1.94 per nesting female (includes recycling efforts that involve laying more than one clutch). They were marked intercolony differences in clutch size and incidence of recycling. Predation (primarily avian) was a major factor that adversely affected nest success in three colonies and was relatively unimportant in two colonies. Residues of DDE, total polychlorinated biphenyls, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and other compounds in eggs were generally low and apparently had little influence on reproductive success at any of the colonies. Mean eggshell thinning ranged from 7-1 1 % in comparison to a pre-1947 norm for eggs measured in museum collections. Cytochrome P450 enzyme (EROD, PROD, and BROD) induction in livers of pipped embryos by colony ranged from low to average in comparison with other colonies throughout the U.S. Average EROD and BROD activities were highest at Sand Dune Island and were lowest at Potholes Reservoir which was designated the reference colony. In relation to our study of three of the five colonies in the early 1980s, residues of DDE and several related compounds appeared to decline, nest predation rates increased, and nest success decreased at all three colonies.

  10. Reproduction of Black-crowned Night-Herons related to predation and contaminants in Oregon and Washington, USA

    USGS Publications Warehouse

    Blus, L.J.; Rattner, B.A.; Melancon, M.J.; Henny, C.J.

    1997-01-01

    We studied reproductive characteristics of Black-crowned Night-Herons (Nycitcorax nycticorax) at 4 colonies in south central Washington and 1 colony in north central Oregon in 1991. Nest success, adjusted using the Mayfield method, was significantly different between colonies and ranged from 12-84% to hatching and 12-73% to 14 days post-hatching. The mean number of young surviving to 14 days of age in each colony ranged from 0.47-1.94 per nesting female (includes recycling efforts that involve laying more than 1 clutch). There were marked intercolony differences in clutch size and incidence of recycling. Predation (primarily avian) was a major factor that adversely affected nest success in 3 colonies and was relatively unimportant in 2 colonies. Residues of DDE, total polychlorinated biphenyls, 2,3,7,8-tetrachlorodibenzo-p-dioxin, and other compounds in eggs were generally low and apparently had little influence on reproductive success at any of the colonies. Mean eggshell thinning ranged from 7-11% in comparison to a pre-1947 norm for eggs measured in museum collections. Cytochrome P450 enzyme (EROD, PROD, and BROD) induction in livers of pipped embryos by colony ranged from low to average in comparison with other colonies throughout the U.S. Average EROD and BROD activities were highest at Sand Dune Island and were lowest at Potholes Reservoir which was designated the reference colony. In relation to our study of 3 of the 5 colonies in the early 1980s, residues of DDE and several related compounds appeared to decline, nest predation rates increased, and nest success decreased at all 3 colonies.

  11. Breeding biology and relation of pollutants to black skimmers and gull-billed terns in South Carolina

    USGS Publications Warehouse

    Blus, Lawrence J.; Stafford, Charles J.

    1980-01-01

    The breeding biology and relation of pollutants to black skimmers (Ryn chops niger) and gull-billed terns (Gelochelidon nilotica) were investigated in South Carolina from 1969 through 1975. With few exceptions, the two species nested together in colonies located on barrier islands. We located 10 colonies, 7 of which were on the Cape Romain National Wildlife Refuge (Cape Romain); references were located that described nesting on seven other islands in South Carolina that no longer support colonies. Gull-billed terns nested from early May through July; the skimmers started later (late May) but also continued later (early September). Both species nested in areas subject to tidal flooding, and the two species persisted in nesting in several colonies despite intense predation by rats and gulls. Estimated reproductive success varied greatly from year to year and colony to colony; success in most colonies seemed low, particularly for the gull-billed tern. Residues of organochlorine pollutants in several eggs seemed of sufficient magnitude to induce adverse effects on reproductivity and eggshell thickness: however, the overall effect of organochlorines appeared negligible. Maximum numbers of nests located in a single year were 790 for the skimmer and 340 for the gull-billed tern: the total breeding population in South Carolina is unknown. Although nesting islands at Cape Romain and Deveaux Bank are sanctuaries for nesting birds, both species will continue to lose nesting habitat as additional sea islands are developed and inhabited by man.

  12. Improved effective-one-body description of coalescing nonspinning black-hole binaries and its numerical-relativity completion

    NASA Astrophysics Data System (ADS)

    Damour, Thibault; Nagar, Alessandro; Bernuzzi, Sebastiano

    2013-04-01

    We improve the effective-one-body (EOB) description of nonspinning coalescing black-hole binaries by incorporating several recent analytical advances, notably: (i) logarithmic contributions to the conservative dynamics; (ii) resummed horizon-absorption contribution to the orbital angular momentum loss; and (iii) a specific radial component of the radiation-reaction force implied by consistency with the azimuthal one. We then complete this analytically improved EOB model by comparing it to accurate numerical-relativity (NR) simulations performed by the Caltech-Cornell-CITA group for mass ratios q=(1,2,3,4,6). In particular, the comparison to NR data allows us to determine with high accuracy (˜10-4) the value of the main EOB radial potential: A(u;ν), where u=GM/(Rc2) is the interbody gravitational potential and ν=q/(q+1)2 is the symmetric mass ratio. We introduce a new technique for extracting from NR data an intrinsic measure of the phase evolution [Qω(ω) diagnostics]. Aligning the NR-completed EOB quadrupolar waveform and the NR one at low frequencies, we find that they keep agreeing (in phase and amplitude) within the NR uncertainties throughout the evolution for all mass ratios considered. We also find good agreement for several subdominant multipoles without having to introduce and tune any extra parameters.

  13. The Nearest Black Holes

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); Garcia, M.

    2003-01-01

    The goal of this program is to study black holes, both in our Galaxy and in nearby galaxies. We aim to study both 'stellar mass' x-ray binaries containing black holes (both in our Galaxy and in nearby galaxies), and super-massive black holes in nearby galaxies. This program facilitates this study by funding related travel, computer equipment, and partial salary for a post-doc.

  14. The Nearest Black Holes

    NASA Technical Reports Server (NTRS)

    Garcia, M.; Oliversen, Ronald J. (Technical Monitor)

    2004-01-01

    The goal of this program is to study black holes, both in our Galaxy and in nearby galaxies. We aim to study both 'stellar mass' x-ray binaries containing black holes (both in our Galaxy and in nearby galaxies), and super-massive black holes in nearby galaxies. This program facilitate this study by funding related travel, computer equipment, and partial salary for a post-doc.

  15. COSMIC EVOLUTION OF BLACK HOLES AND SPHEROIDS. IV. THE M{sub BH}-L{sub sph} RELATION

    SciTech Connect

    Bennert, Vardha Nicola; Treu, Tommaso; Le Bris, Alexandre; Auger, Matthew W.; Woo, Jong-Hak; Malkan, Matthew A.; Gallagher, Sarah; Blandford, Roger D. E-mail: tt@physics.ucsb.ed E-mail: woo@astro.ucla.ed E-mail: alexandrelebris@gmail.co E-mail: rdb@slac.stanford.ed

    2010-01-10

    From high-resolution images of 23 Seyfert-1 galaxies at z = 0.36 and z = 0.57 obtained with the Near-Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope (HST), we determine host-galaxy morphology, nuclear luminosity, total host-galaxy luminosity, and spheroid luminosity. Keck spectroscopy is used to estimate black hole mass (M{sub BH}). We study the cosmic evolution of the M{sub BH}-spheroid luminosity (L{sub sph}) relation. In combination with our previous work, totaling 40 Seyfert-1 galaxies, the covered range in BH mass is substantially increased, allowing us to determine for the first time intrinsic scatter and correct evolutionary trends for selection effects. We re-analyze archival HST images of 19 local reverberation-mapped active galaxies to match the procedure adopted at intermediate redshift. Correcting spheroid luminosity for passive luminosity evolution and taking into account selection effects, we determine that at fixed present-day V-band spheroid luminosity, M{sub BH}/L{sub sph} propor to(1 + z){sup 2.8+}-{sup 1.2}. When including a sample of 44 quasars out to z = 4.5 taken from the literature, with luminosity and BH mass corrected to a self-consistent calibration, we extend the BH mass range to over 2 orders of magnitude, resulting in M{sub BH}/L{sub sph} propor to(1 + z){sup 1.4+}-{sup 0.2}. The intrinsic scatter of the relation, assumed constant with redshift, is 0.3 +- 0.1 dex (<0.6 dex at 95% CL). The evolutionary trend suggests that BH growth precedes spheroid assembly. Interestingly, the M{sub BH}-total-host-galaxy-luminosity relation is apparently non-evolving. It hints at either a more fundamental relation or that the spheroid grows by a redistribution of stars. However, the high-z sample does not follow this relation, indicating that major mergers may play the dominant role in growing spheroids above z approx = 1.

  16. A LOCAL BASELINE OF THE BLACK HOLE MASS SCALING RELATIONS FOR ACTIVE GALAXIES. I. METHODOLOGY AND RESULTS OF PILOT STUDY

    SciTech Connect

    Bennert, Vardha Nicola; Auger, Matthew W.; Treu, Tommaso; Woo, Jong-Hak; Malkan, Matthew A. E-mail: mauger@physics.ucsb.edu E-mail: woo@astro.snu.ac.kr

    2011-01-10

    We present high-quality Keck/LRIS long-slit spectroscopy of a pilot sample of 25 local active galaxies selected from the SDSS (0.02 {<=}z {<=} 0.1; M{sub BH}>10{sup 7} M{sub sun}) to study the relations between black hole mass (M{sub BH}) and host-galaxy properties. We determine stellar kinematics of the host galaxy, deriving stellar-velocity dispersion profiles and rotation curves from three spectral regions (including CaH and K, MgIb triplet, and Ca II triplet). In addition, we perform surface photometry on SDSS images, using a newly developed code for joint multi-band analysis. BH masses are estimated from the width of the H{beta} emission line and the host-galaxy free 5100 A active galactic nucleus (AGN) luminosity. Combining results from spectroscopy and imaging allows us to study four M{sub BH} scaling relations: M{sub BH}-{sigma}, M{sub BH}-L{sub sph}, M{sub BH}-M{sub sph,*}, and M{sub BH}-M{sub sph,dyn}. We find the following results. First, stellar-velocity dispersions determined from aperture spectra (e.g., SDSS fiber spectra or unresolved data from distant galaxies) can be biased, depending on aperture size, AGN contamination, and host-galaxy morphology. However, such a bias cannot explain the offset seen in the M{sub BH}-{sigma} relation at higher redshifts. Second, while the CaT region is the cleanest to determine stellar-velocity dispersions, both the MgIb region, corrected for Fe II emission, and the CaHK region, although often swamped by the AGN power-law continuum and emission lines, can give results accurate to within a few percent. Third, the M{sub BH} scaling relations of our pilot sample agree in slope and scatter with those of other local active and inactive galaxies. In the next papers of the series we will quantify the scaling relations, exploiting the full sample of {approx}100 objects.

  17. Black holes

    PubMed Central

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

    2001-01-01

    Recent progress in black hole research is illustrated by three examples. We discuss the observational challenges that were met to show that a supermassive black hole exists at the center of our galaxy. Stellar-size black holes have been studied in x-ray binaries and microquasars. Finally, numerical simulations have become possible for the merger of black hole binaries. PMID:11553801

  18. Black holes.

    PubMed

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

    2001-09-11

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

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

    PubMed Central

    Logie, Carmen H.; Jenkinson, Jesse I. R.; Earnshaw, Valerie; Tharao, Wangari; Loutfy, Mona R.

    2016-01-01

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

  20. Evidence for black holes.

    PubMed

    Begelman, Mitchell C

    2003-06-20

    Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity.

  1. On the formation of compact, massive subsystems in stellar clusters and its relation with intermediate-mass black holes

    NASA Astrophysics Data System (ADS)

    Arca-Sedda, M.

    2016-01-01

    During their evolution, star clusters undergo mass segregation, by which the orbits of the most massive stars shrink, while the lighter stars move outwards from the cluster centre. In this context, recent observations and dynamical modelling of several galactic and extragalactic globular clusters (GCs) suggest that most of them show, close to their centre, an overabundance of mass whose nature is still matter of debate. For instance, many works show that orbitally segregated stars may collide with each other in a runaway fashion, leading to the formation of a very massive star or an intermediate-mass black hole (IMBH) with a mass comparable to the observed mass excess. On the other hand, segregated stars can form a dense system if the IMBH formation fails. In this paper we study the early formation phase of a dense, massive subsystem (MSS) in several GCs models using a recently developed semi-analytical treatment of the mass segregation process. In order to investigate how the MSS properties depend on the host cluster properties, we varied initial mass function (IMF), total mass, spatial distribution and metallicity of our models. Our results show how the IMF contributes to determine the final mass of the MSS, while the metallicity and the spatial distribution play a minor role. The method presented in this paper allowed us to provide scaling relations that connect the MSS mass and the host cluster mass in agreement with the observed correlation. In order to follow the early formation stage of the MSSs and improve our statistical results, we performed several N-body simulations of stellar clusters with masses between 103 and 2 × 105 M⊙.

  2. Effective-one-body waveforms calibrated to numerical relativity simulations: Coalescence of nonprecessing, spinning, equal-mass black holes

    SciTech Connect

    Pan Yi; Buonanno, Alessandra; Buchman, Luisa T.; Chu, Tony; Scheel, Mark A.; Kidder, Lawrence E.; Pfeiffer, Harald P.

    2010-04-15

    We present the first attempt at calibrating the effective-one-body (EOB) model to accurate numerical relativity simulations of spinning, nonprecessing black-hole binaries. Aligning the EOB and numerical waveforms at low frequency over a time interval of 1000M, we first estimate the phase and amplitude errors in the numerical waveforms and then minimize the difference between numerical and EOB waveforms by calibrating a handful of EOB-adjustable parameters. In the equal-mass, spin aligned case, we find that phase and fractional amplitude differences between the numerical and EOB (2,2) mode can be reduced to 0.01 radian and 1%, respectively, over the entire inspiral waveforms. In the equal-mass, spin antialigned case, these differences can be reduced to 0.13 radian and 1% during inspiral and plunge, and to 0.4 radian and 10% during merger and ringdown. The waveform agreement is within numerical errors in the spin aligned case while slightly over numerical errors in the spin antialigned case. Using Enhanced LIGO and Advanced LIGO noise curves, we find that the overlap between the EOB and the numerical (2,2) mode, maximized over the initial phase and time of arrival, is larger than 0.999 for binaries with total mass 30M{sub {center_dot}-}200M{sub {center_dot}}. In addition to the leading (2,2) mode, we compare four subleading modes. We find good amplitude and frequency agreements between the EOB and numerical modes for both spin configurations considered, except for the (3,2) mode in the spin antialigned case. We believe that the larger difference in the (3,2) mode is due to the lack of knowledge of post-Newtonian spin effects in the higher modes.

  3. Foraging strategies of black-fronted titi monkeys (Callicebus nigrifrons) in relation to food availability in a seasonal tropical forest.

    PubMed

    Nagy-Reis, Mariana B; Setz, Eleonore Z F

    2017-01-01

    Many primates have to cope with a temporal scarcity in food availability that shapes their foraging strategies. Here we investigated the changes in diet, activity, and ranging behavior of a group of black-fronted titi monkeys (Callicebus nigrifrons) according to the availability of the main high-nutritional-density item in their diet and the foraging strategy adopted when this food is scarce. We monitored one habituated group using instantaneous scan sampling over 1 year (533 h of observation, 61 days) in a seasonal tropical forest fragment (245 ha). We simultaneously collected data on food availability with fruit traps. The titi monkeys consumed fleshy fruits, the main high-nutritional-density item of their diet, in accordance with its availability, and the availability of this item modulated the ingestion of vegetative plant parts, a relatively low-nutritional-density food. During high fleshy fruit availability, the titi monkeys consumed more fleshy fruits, flowers, and invertebrates. They also traveled more, but concentrated their activity in a central area of their home range. Conversely, during fleshy fruit scarcity, they increased the breadth of their diet, switching to one richer in seeds and vegetative plant parts, and with greater plant diversity. At the same time, they reduced most energy-demanding activities, traveling less and over shorter distances, but using their home range more broadly. Corroborating the optimal foraging theory, titi monkeys altered foraging strategies according to temporal food fluctuations and responded to low fleshy fruit availability by changing their diet, activity, and ranging behavior. The adoption of a low-cost/low-yield strategy allowed us to classify them as energy minimizers.

  4. Supermassive Black Holes

    NASA Astrophysics Data System (ADS)

    Loeb, Abraham

    2007-04-01

    Recent data indicates that almost all galaxies possess a supermassive black hole at their center. When gas accretes onto the black hole it heats-up and shines, resulting in the appearance of a bright quasar. The earliest quasars are found to exist only a billion years after the big-bang. I will describe recent observations of both the nearest and the most distant supermassive black holes in the universe. The formation and evolution of the black hole population can be described in the context of popular models for galaxy formation. I will describe the key questions that drive current research on supermassive black holes and present theoretical work on the radiative and hydrodynamic effects that quasars have on their cosmic habitat. Within the coming decade it would be possible to test general relativity by monitoring over time, and possibly even imaging, the polarized emission from hot spots around the black hole in the center of our Galaxy (SgrA*).

  5. Aspects of black-fly control and entomology in the New World in relation to the Simulium problem in Nigeria*

    PubMed Central

    Crosskey, R. W.

    1959-01-01

    A general account is given of insecticidal control of black-flies in North and Central America, and the problems are contrasted with those arising in the control of Simulium damnosum Theo. in Nigeria. Some recent biological observations on Canadian black-flies are described, and it is emphasized that these have materially contributed to successful control. It is pointed out that S. damnosum control is being practised in the absence of much fundamental biological knowledge of this pest. Entomological aspects of onchocerciasis in Mexico and Guatemala are discussed, and compared with S. damnosum and its relationship to onchocerciasis in Nigeria. PMID:13813021

  6. Beyond the Black-White Binary of U.S. Race Relations: A Next Step in Religious Education

    ERIC Educational Resources Information Center

    Goto, Courtney T.

    2017-01-01

    Many if not most people in the academy as well as the public sphere tend to regard race and racism in the United States in terms of a default frame of reference (i.e., a paradigm): the black-white binary. Although this frame is constructive as well as compelling, it displays serious liabilities. This article outlines, for religious educators, nine…

  7. Coping and Social Support as Mediators of the Relation of Optimism to Depressive Symptoms among Black College Students

    ERIC Educational Resources Information Center

    Mosher, Catherine E.; Prelow, Hazel M.; Chen, William W.; Yackel, Molly E.

    2006-01-01

    This investigation examines mechanisms through which optimism may influence psychological adjustment among 133 Black college students. Specifically, this study evaluates the extent to which active and avoidant coping and social support account for the association between optimism and depressive symptoms. Participants completed questionnaires that…

  8. Toward a Relational Perspective on Young Black and Latino Males: The Contextual Patterns of Disclosure as Coping

    ERIC Educational Resources Information Center

    Knight, David J.

    2014-01-01

    In this article, David J. Knight investigates where and when Black and Latino male adolescents engage in self-disclosure--sharing their emotions, thoughts, and social perceptions--with their peers. Building from asset-based research and ecological theories of development, Knight analyzes in-depth interviews and finds that these adolescents may…

  9. Observing Black Hole Spin

    NASA Astrophysics Data System (ADS)

    Reynolds, Christopher S.

    2015-08-01

    Black hole spin is important in both the fundamental physics and astrophysics realms. In fundamental terms, many extensions and alternatives to General Relativity (GR) reveal themselves through effects related to (or at least of the same order as) spin. Astrophysically, spin is a fossil record of how black holes have grown and may, in addition, be an important source of energy (e.g., powering relativistic jets from black hole systems). I shall review recent progress on observational studies of black hole spin, especially those made in the X-ray waveband. We now have multiple techniques that can be applied in our search for black hole spin; I shall discuss the concordance (or, sometimes, lack thereof) between these techniques. Finally, I shall discuss what we can expect in the next few years with the launch of new X-ray instrumentation as well as the deployment of the Event Horizon Telescope.

  10. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans

    PubMed Central

    Lumpkins, Crystal Y.; Bae, Jiyang; Cameron, Glen T.

    2010-01-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy. PMID:22822291

  11. Generating Conflict for Greater Good: Utilizing Contingency Theory to Assess Black and Mainstream Newspapers as Public Relations Vehicles to Promote Better Health among African Americans.

    PubMed

    Lumpkins, Crystal Y; Bae, Jiyang; Cameron, Glen T

    2010-03-01

    The potential use of strategic conflict management ( Wilcox and Cameron, 2006; Cameron, Wilcox, Reber and Shin ( in press) as a health advocacy tool in US African-American and mainstream newspapers, arguing that escalation of conflict can increase effectiveness of health-related news releases. For health communicators focusing on at-risk populations with poor health outcomes, such goals would include increased awareness of health problems and solutions, along with increased motivation arising from indignation over health disparities. Content analysis of 1,197 stories in 24 Black and 12 mainstream newspapers showed that more conflict factors were present in Black vs. mainstream newspapers, suggesting a way to strategically place health messages in news releases disseminated to newspapers that motivate at-risk publics to better health. The findings suggest that conflict factors such as racial disparity data regarding health issues may enhance media advocacy.

  12. THE MASSIVE-BLACK-HOLE-VELOCITY-DISPERSION RELATION AND THE HALO BARYON FRACTION: A CASE FOR POSITIVE ACTIVE GALACTIC NUCLEUS FEEDBACK

    SciTech Connect

    Silk, Joseph; Nusser, Adi E-mail: adi@physics.technion.ac.i

    2010-12-10

    Force balance considerations put a limit on the rate of active galactic nucleus radiation momentum output, L/c, capable of driving galactic superwinds and reproducing the observed M{sub BH}-{sigma} relation between black hole mass and spheroid velocity dispersion. We show that black holes cannot supply enough momentum in radiation to drive the gas out by pressure alone. Energy-driven winds give a M{sub BH}-{sigma} scaling favored by a recent analysis but also fall short energetically once cooling is incorporated. We propose that outflow triggering of star formation by enhancing the intercloud medium turbulent pressure and squeezing clouds can supply the necessary boost and suggest possible tests of this hypothesis. Our hypothesis simultaneously can account for the observed halo baryon fraction.

  13. Black Students.

    ERIC Educational Resources Information Center

    Edwards, Harry

    The black student revolt did not start with the highly publicized activities of the black students at San Francisco State College. The roots of the revolt lie deeply imbedded within the history and structure of the overall black liberation struggle in America. The beginnings of this revolt can be found in the students of Southern Negro colleges in…

  14. Black Psychology.

    ERIC Educational Resources Information Center

    Jones, Reginald L., Ed.

    The contents of the present volume, designed to bring together in a single place writings by the new black psychologists and other black social and behavioral scientists, are organized in seven parts, as follows: Part I, "Black Psychology: Perspectives," includes articles by Cedric Clark, Wade W. Nobles, Doris P. Mosby, Joseph White, and William…

  15. On the instability of the n = 1 Einstein-Yang-Mills black holes and mathematically related systems.

    NASA Astrophysics Data System (ADS)

    Wald, R. M.

    1992-01-01

    The usual approach to analyze the linear stability of a static solution of some system of equations consists of searching for linearized solutions which satisfy suitable boundary conditions spatially and which grow exponentially in time. In the case of the n = 1 Einstein-Yang-Mills (EYM) black hole, an interesting situation occurs. There exists a perturbation which grows exponentially in time-and spatially decreases to zero at the horizon-but nevertheless is physically singular on the horizon. Thus, this unstable mode is unacceptable as initial data, and the question arises as to whether the n = 1 EYM black hole is stable. The author analyzes this issue here in the more general case. He proves that there exists smooth initial data of compact support in M which give rise to a solution which grows unboundedly with time. This implies that the n = 1 EYM black hole and other mathematically similar systems are unstable despite the nonexistence of physically acceptable exponentially growing modes.

  16. Illuminating black holes

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

    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.

  17. Adolescent experiences of violence and relation to violence perpetration beyond young adulthood among an urban sample of Black and African American males.

    PubMed

    Reed, Elizabeth; Lawrence, Danielle A; Santana, M C; Welles, C Seth L; Horsburgh, C Robert; Silverman, Jay G; Rich, John A; Raj, Anita

    2014-02-01

    The purpose of this study is to determine if experiences of physical violence during early and late adolescence (12-21 years) places urban Black males at increased risk for interpersonal violence perpetration beyond young adulthood (30 years and older). Participants of this cross-sectional study were Black and African American men (N = 455) between the ages of 30 and 65 years, recruited from four urban clinical sites in the Northeast. Multivariate logistic regression models were used to analyze the relation of adolescent experiences of violence to: (1) past 6 month street violence involvement and (2) past year intimate partner violence perpetration. Ten percent of the sample reported that they experienced adolescent victimization. Men reporting adolescent victimization were significantly more likely to report past 6-month street violence involvement (Adjusted Odds Ratio (AOR) = 3.2, 95 % CI = 1.7-6.3) and past 6 month intimate partner violence perpetration (AOR = 2.8, 95 % CI = 1.8-5.4) compared to men who did not report such victimization. Study findings suggest that in order to prevent adulthood perpetration of violence, more work is needed to address experiences of victimization among young Black males, particularly violence experienced during adolescence.

  18. ADIPOQ, ADIPOR1, and ADIPOR2 Polymorphisms in Relation to Serum Adiponectin Levels and Body Mass Index in Black and White Women

    PubMed Central

    Cohen, Sarah S.; Gammon, Marilie D.; North, Kari E.; Millikan, Robert C.; Lange, Ethan M.; Williams, Scott M.; Zheng, Wei; Cai, Qiuyin; Long, Jirong; Smith, Jeffrey R.; Signorello, Lisa B.; Blot, William J.; Matthews, Charles E.

    2012-01-01

    Adiponectin is an adipose-secreted protein with influence on several physiologic pathways including those related to insulin sensitivity, inflammation, and atherogenesis. Adiponectin levels are highly heritable and several single nucleotide polymorphisms (SNPs) in adiponectin-related genes (ADIPOQ, ADIPOR1, ADIPOR2) have been examined in relation to circulating adiponectin levels and obesity phenotypes, but despite differences in adiponectin levels and obesity prevalence by race, few studies have included black participants. Using cross-sectional interview data and blood samples collected from 990 black and 977 white women enrolled in the Southern Community Cohort Study from 2002 to 2006, we examined 25 SNPs in ADIPOQ, 19 in ADIPOR1, and 27 in ADIPOR2 in relation to serum adiponectin levels and body mass index (BMI) using race-stratified linear regression models adjusted for age and percentage African ancestry. SNP rs17366568 in ADIPOQ was significantly associated with serum adiponectin levels in white women only (adjusted mean adiponectin levels = 15.9 for G/G genotype, 13.7 for A/G, and 9.3 for A/A, p=0.00036). No other SNPs were associated with adiponectin or BMI among blacks or whites. Because adiponectin levels as well as obesity are highly heritable and vary by race but associations with polymorphisms in the ADIPOQ, ADIPOR1, and ADIPOR2 genes have been few in this and other studies, future work including large populations from diverse racial groups is needed to detect additional genetic variants that influence adiponectin and BMI. PMID:21273992

  19. Black phosphorus gas sensors.

    PubMed

    Abbas, Ahmad N; Liu, Bilu; Chen, Liang; Ma, Yuqiang; Cong, Sen; Aroonyadet, Noppadol; Köpf, Marianne; Nilges, Tom; Zhou, Chongwu

    2015-05-26

    The utilization of black phosphorus and its monolayer (phosphorene) and few-layers in field-effect transistors has attracted a lot of attention to this elemental two-dimensional material. Various studies on optimization of black phosphorus field-effect transistors, PN junctions, photodetectors, and other applications have been demonstrated. Although chemical sensing based on black phosphorus devices was theoretically predicted, there is still no experimental verification of such an important study of this material. In this article, we report on chemical sensing of nitrogen dioxide (NO2) using field-effect transistors based on multilayer black phosphorus. Black phosphorus sensors exhibited increased conduction upon NO2 exposure and excellent sensitivity for detection of NO2 down to 5 ppb. Moreover, when the multilayer black phosphorus field-effect transistor was exposed to NO2 concentrations of 5, 10, 20, and 40 ppb, its relative conduction change followed the Langmuir isotherm for molecules adsorbed on a surface. Additionally, on the basis of an exponential conductance change, the rate constants for adsorption and desorption of NO2 on black phosphorus were extracted for different NO2 concentrations, and they were in the range of 130-840 s. These results shed light on important electronic and sensing characteristics of black phosphorus, which can be utilized in future studies and applications.

  20. The Black Community: Diversity and Unity.

    ERIC Educational Resources Information Center

    Blackwell, James E.

    The black community is defined in this book as a diversified set of interrelated structures and aggregates of people who are held together by the forces of racism. The need for theoretical perspectives for understanding black-white relations and for analyzing the nature of the black community is explained. The black family, patterns of family…

  1. Hierarchical data-driven approach to fitting numerical relativity data for nonprecessing binary black holes with an application to final spin and radiated energy

    NASA Astrophysics Data System (ADS)

    Jiménez-Forteza, Xisco; Keitel, David; Husa, Sascha; Hannam, Mark; Khan, Sebastian; Pürrer, Michael

    2017-03-01

    Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs). It is still computationally prohibitive to cover the BBH parameter space exhaustively, making phenomenological fitting formulas for BBH waveforms and final-state properties important for practical applications. We describe a general hierarchical bottom-up fitting methodology to design and calibrate fits to numerical relativity simulations for the three-dimensional parameter space of quasicircular nonprecessing merging BBHs, spanned by mass ratio and by the individual spin components orthogonal to the orbital plane. Particular attention is paid to incorporating the extreme-mass-ratio limit and to the subdominant unequal-spin effects. As an illustration of the method, we provide two applications, to the final spin and final mass (or equivalently: radiated energy) of the remnant black hole. Fitting to 427 numerical relativity simulations, we obtain results broadly consistent with previously published fits, but improving in overall accuracy and particularly in the approach to extremal limits and for unequal-spin configurations. We also discuss the importance of data quality studies when combining simulations from diverse sources, how detailed error budgets will be necessary for further improvements of these already highly accurate fits, and how this first detailed study of unequal-spin effects helps in choosing the most informative parameters for future numerical relativity runs.

  2. Three studies of factors affecting the attitudes of blacks and females toward the pursuit of science and science-related careers

    NASA Astrophysics Data System (ADS)

    Hill, Oliver W.; Pettus, W. Clinton; Hedin, Barbara A.

    This study involved the development of an instrument, the Science Career Predictor Scale (SCPS), which assesses seven factors thought to be involved with science career choices: teacher/counselor encouragement, participation in science-related hobbies and activities, academic self-image, science-related career interest, parental encouragement and support, the perceived relevance of mathematics and science, and mathematics and science ability. This instrument was administered to a sample of 522 middle and high school students, and a sample of 185 students from an historically black university, and the effects of such factors as sex, race, personal acquaintance with a scientist, and type of community (rural or urban) on the above-mentioned variables were ascertained using a multivariate analysis of covariance with age as the covariate. A separate study on a sample of 81 high school students looked at race and gender differences in critical thinking abilities as measured by the Watson-Glaser Critical Thinking appraisal, and how these abilities correlated with scores on the Science Career Predictor Scale. These studies produced several significant findings. Female subjects did produce significantly lower scores on the career interest factor. Black students actually had significantly higher science-career preference scores than their white counterparts. However, blacks scored significantly lower on the measure of critical thinking ability. Across both races and both sexes, however, the major factor affecting science-related career decisions appears to be personal contact with a scientist. The implications of these findings are discussed, along with possible strategies for increasing the participation of these groups in science.

  3. The Relative Impact of Socioeconomic Status and Childhood Trauma on Black-White Differences in Paranoid Personality Disorder Symptoms

    PubMed Central

    Iacovino, Juliette M.; Jackson, Joshua J.; Oltmanns, Thomas F.

    2015-01-01

    The current study examines mechanisms of racial differences in symptoms of paranoid personality disorder (PPD) in a sample of adults ages 55–64 from the St. Louis, MO area. Socioeconomic status (SES) and childhood trauma were tested as intervening variables in the association between race and PPD symptoms using structural equation modeling. PPD symptoms were modeled as a latent variable composed of items from the PPD scales of the Multi-Source Assessment of Personality Pathology self and informant reports and the Structured Interview for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM–IV) Personality. Childhood trauma was measured using the Traumatic Life Events Questionnaire, and SES was a composite of parent education, participant education, and annual household income. Blacks exhibited higher levels of PPD symptoms across the 3 personality measures, reported significantly lower SES, and reported greater childhood trauma. The proposed model was a good fit to the data, and the effect of race on PPD symptoms operated mainly through SES. The indirect effect through SES was stronger for males. Findings suggest that racial differences in PPD symptoms are partly explained by problems more commonly experienced by Black individuals. PMID:24661172

  4. Relationship between Human Immunodeficiency Virus (HIV) Knowledge, HIV-Related Stigma, and HIV Testing among Young Black Adults in a Southeastern City

    PubMed Central

    Okumu, Eunice; Jolly, David H.; Alston, Le’Marus; Eley, Natalie T.; Laws, Michelle; MacQueen, Kathleen M.

    2017-01-01

    The southeast is identified as the epicenter of the nation’s human immunodeficiency virus (HIV) epidemic, accounting for nearly 44% of all persons living with a HIV diagnosis in the United States. HIV stigma and knowledge have been cited as some of the complex factors increasing risk of acquiring HIV within African-American communities. We sought to understand how HIV knowledge and HIV-related stigma impact HIV testing experience among young Black adults who completed a community-based participatory research survey in a Southeastern city. Survey measures were developed with active engagement among the research team and community members, with the goal of balancing community knowledge, interests and concerns with scientific considerations, and the realities of funding and the project timeline. A total of 508 of the 513 audio computer-assisted self-interview questionnaires completed were analyzed. Eighty-one percent of participants had ever tested and had an intention-to-test for HIV in the next 12 months. Overall, analyses revealed low HIV-related stigma and relatively moderate to high HIV knowledge among young Black adults in the Southeastern city. Logistic regression indicated that having ever tested for HIV was positively correlated with HIV knowledge [odds ratio (OR): 1.50; 95% confidence interval (CI): 1.23–1.84, p < 0.001], but inversely correlated with low HIV-related stigma (OR: 0.08; 95% CI: 0.01–0.76, p < 0.03). However, there were no significant relationships between HIV-related stigma, HIV knowledge, and intention-to test for HIV in the future. These findings suggest that reducing HIV-related stigma and increasing HIV knowledge are not sufficient in promoting HIV testing (i.e., intention-to-test) among young Black adults in this city, unless specific emphasis is placed on addressing internalized HIV-related stigma and misperceptions about HIV prevention and control. PMID:28349049

  5. Satellite observation of bio-optical indicators related to North-Western Black Sea coastal zone changes

    NASA Astrophysics Data System (ADS)

    Zoran, Maria

    Satellite remote sensing provides a means for locating, identifying and mapping certain coastal zone features and assessing of spatio-temporal changes.The Romanian coastal zone of the Black Sea is a mosaic of complex, interacting ecosystems, exposed to dramatic changes due to natural and anthropogenic causes (increase in the nutrient and pollutant load of rivers input, industrial and municipal wastewater pollution along the coast, and dumping on the open sea). This study focuses on the assessment of coastal zone land cover changes based on the fusion of satellite remote sensing data.The evaluation of coastal zone landscapes is based upon different sub-functions which refer to landscape features such as water, soil, land-use, buildings, groundwater, biotope types. Mixed pixels result when the sensor's instantaneous field-of-view includes more than one land cover class on the ground. Based on different satellite data (Landsat TM, ETM, SAR ERS, IKONOS, Quickbird, and MODIS) was performed object recognition for North-Western Black Sea coastal zone. Preliminary results show significant coastline position changes of North Western Black Sea during the period of 1987-2007 and urban growth of Constantza town. Also the change in the position of the coastline is examined and linked to the urban expansion in order to determine if the changes are natural or anthropogenic. A distinction is made between landfill/sedimentation processes on the one hand and dredging/erosion processes on the other. Waves play an important role for shoreline configuration. Wave pattern could induce erosion and sedimentation. A quasi-linear model was used to model the rate of shoreline change. The vectors of shoreline were used to compare with wave spectra model in order to examine the accuracy of the coastal erosion model. The shoreline rate modeled from vectors data of SAR ERS-1 has a good correlation with a quasi-linear model. Wave refraction patterns are a good index for shoreline erosion. A coast

  6. Relativity

    NASA Astrophysics Data System (ADS)

    Stephani, Hans

    2004-02-01

    Preface; Notation; Part I. Special Relativity: 1. Introduction: inertial systems and Galilei invariance of classical mechanics; 2. Light propagation in moving coordinate systems and Lorentz transformations; 3. Our world as a Minkowski space; 4. Mechanics of special relativity; 5. Optics of plane waves; 6. Four-dimensional vectors and tensors; 7. Electrodynamics in vacuo; 8. Transformation properties of electromagnetic fields: examples; 9. Null vectors and the algebraic properties of electromagnetic field tensors; 10. Charged point particles and their field; 11. Pole-dipole particles and their field; 12. Electrodynamics in media; 13. Perfect fluids and other physical theories; Part II. Riemannian Geometry: 14. Introduction: the force-free motion of particles in Newtonian mechanics; 15. Why Riemannian geometry?; 16. Riemannian space; 17. Tensor algebra; 18. The covariant derivative and parallel transport; 19. The curvature tensor; 20. Differential operators, integrals and integral laws; 21. Fundamental laws of physics in Riemannian spaces; Part III. Foundations of Einstein's Theory of Gravitation: 22. The fundamental equations of Einstein's theory of gravitation; 23. The Schwarzschild solution; 24. Experiments to verify the Schwarzschild metric; 25. Gravitational lenses; 26. The interior Schwarzschild solution; Part IV. Linearized Theory of Gravitation, Far Fields and Gravitational Waves: 27. The linearized Einstein theory of gravity; 28. Far fields due to arbitrary matter distributions and balance equations for momentum and angular momentum; 29. Gravitational waves; 30. The Cauchy problem for the Einstein field equations; Part V. Invariant Characterization of Exact Solutions: 31. Preferred vector fields and their properties; 32. The Petrov classification; 33. Killing vectors and groups of motion; 34. A survey of some selected classes of exact solutions; Part VI. Gravitational Collapse and Black Holes: 35. The Schwarzschild singularity; 36. Gravitational collapse

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

    PubMed

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

    2013-04-01

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

  8. Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon.

    PubMed

    Duggal, K L

    2016-01-01

    A new technique is used to study a family of time-dependent null horizons, called "Evolving Null Horizons" (ENHs), of generalized Robertson-Walker (GRW) space-time [Formula: see text] such that the metric [Formula: see text] satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in [Formula: see text]. Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems.

  9. The BlackBerry Project: The Hidden World of Adolescents’ Text Messaging and Relations With Internalizing Symptoms

    PubMed Central

    Underwood, Marion K.; Ehrenreich, Samuel E.; More, David; Solis, Jerome S.; Brinkley, Dawn Y.

    2013-01-01

    In this naturalistic study of adolescents’ text messaging, participants (N = 172, 81 girls, age 14) were given BlackBerry devices configured to save their text messages to a secure archive for coding. Two, 2-day transcripts collected four months apart within the same academic year were microcoded for content. Results showed that most text message utterances were positive or neutral, and that adolescents sent text messages primarily to peers and to romantic partners. Only a few sex differences emerged. Frequency of text messages containing negative talk positively predicted overall internalizing symptoms and anxious depression. Text messaging about sex was positively associated with overall internalizing and somatic complaints for girls, but not for boys. PMID:25750494

  10. Generalized Robertson-Walker Space-Time Admitting Evolving Null Horizons Related to a Black Hole Event Horizon

    PubMed Central

    2016-01-01

    A new technique is used to study a family of time-dependent null horizons, called “Evolving Null Horizons” (ENHs), of generalized Robertson-Walker (GRW) space-time (M¯,g¯) such that the metric g¯ satisfies a kinematic condition. This work is different from our early papers on the same issue where we used (1 + n)-splitting space-time but only some special subcases of GRW space-time have this formalism. Also, in contrast to previous work, we have proved that each member of ENHs is totally umbilical in (M¯,g¯). Finally, we show that there exists an ENH which is always a null horizon evolving into a black hole event horizon and suggest some open problems. PMID:27722202

  11. Discoid lupus erythematosus-related squamous cell carcinoma of the lip in an HIV-seropositive black male.

    PubMed

    Molomo, Edward M; Bouckaert, Michael; Khammissa, Razia A G; Motswaledi, Hendrick M; Lemmer, Johan; Feller, Liviu

    2015-01-01

    Discoid lupus erythematosus (DLE) is an autoimmune disease commonly affecting sun-exposed areas of the skin. Subjects with DLE have high-levels of plasmacytoid dendritic cells -derived interferon-α, which mediates both loss of immune tolerance to self-antigens and exaggerated inflammatory state, and supports proliferation and differentiation of hyperactive B-cells. In a few cases, DLE of the lips, scalp, ears or nose may eventually progress to squamous cell carcinoma (SCC). Photosensitivity and the long-standing immune-mediated chronic inflammation and dysregulated healing characterized by atrophy, hypopigmentation or scarring inherent to DLE are risk factors for progression to SCC. We review some aspects of the pathogenesis of DLE and the possible roles of inflammation and photosensitivity in the carcinomatous transformation of DLE keratinocytes, and present an illustrative case of DLE of the lower lip in an HIV-tuberculosis co-infected black person, that progressed to SCC.

  12. Black Suicide and the Relational System: Theoretical and Empirical Implications of Communal and Familial Ties. Discussion Papers No. 481-78.

    ERIC Educational Resources Information Center

    Davis, Robert

    The findings of a national study of black suicide are reported in this paper. A suitable explanation is sought for the increasing suicide rate among young blacks. The possibility of a link between suicide and the weakening of black community and family ties is explored. Specifically, the isolating effects of inmigration and living alone are…

  13. Black Appalachians.

    ERIC Educational Resources Information Center

    Waage, Fred, Ed.; Cabbell, Ed, Ed.

    1986-01-01

    This issue of "Now and Then" focuses on black Appalachians, their culture, and their history. It contains local histories, articles, and poems and short stories by Appalachian blacks. Articles include: "A Mountain Artist's Landscape," a profile of artist Rita Bradley by Pat Arnow; "A Part and Apart," a profile of…

  14. The relation of racial identity, ethnic identity, and racial socialization to discrimination-distress: a meta-analysis of Black Americans.

    PubMed

    Lee, Debbiesiu L; Ahn, Soyeon

    2013-01-01

    This meta-analysis synthesized the results of 27 studies examining the relations of racial identity, ethnic identity, and racial socialization to discrimination-distress for Black Americans. The purpose was to uncover which constructs connected to racial identity, ethnic identity, and racial socialization most strongly correlate with racial discrimination and psychological distress. Discrimination significantly related to aspects of racial identity, including immersion-emersion, public regard, encounter, Afrocentricity/racial centrality/private regard, and internalization. Distress significantly correlated with preencounter/assimilation, encounter, public regard, immersion-emersion, and Afrocentricity/racial centrality/private regard. Several of these relationships were significantly moderated by the measure of racial identity or demographic variables (gender or age). Implications of these findings are discussed.

  15. Relation among cytochrome P450, Ah-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos

    SciTech Connect

    Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W. . Patuxent Environmental Science Center); Tillitt, D.E. . Midwest Science Center)

    1994-11-01

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P450-associated mono-oxygenates and cytochrome P450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r[sup 2] often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the AH receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.

  16. Relation among cytochrome P450, Ah-active PCB congeners and dioxin equivalents in pipping black- crowned night-heron embryos

    USGS Publications Warehouse

    Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillitt, D.E.

    1994-01-01

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P450-associated monooxygenases and cytochrome P450 proteins, induced up to 85- fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r super(2) often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah- active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.

  17. Relation among cytochrome P450, AH-active PCB congeners and dioxin equivalents in pipping black-crowned night-heron embryos

    USGS Publications Warehouse

    Rattner, B.A.; Hatfield, J.S.; Melancon, M.J.; Custer, T.W.; Tillitt, D.E.

    1994-01-01

    Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from a relatively uncontaminated site (next to Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, Lake Michigan, WI; Bair Island, San Francisco Bay, CA; West Marin Island, San Francisco Bay, CA). Hepatic cytochrome P-450-associated monooxygenases and cytochrome P-450 proteins, induced up to 85-fold relative to the reference site, were associated with concentrations of total polychlorinated biphenyls (PCBs) and 11 PCB congeners that are presumed to express toxicity through the arylhydrocarbon (Ah) receptor. Multiple regression revealed that up to 86% of the variation of cytochrome P450 measurements was accounted for by variation in the concentration of these PCB congeners. Toxic equivalents (TEQs) of sample extracts, predicted mathematically (summed product of PCB congener concentrations and toxic equivalency factors), and dioxin equivalents (TCDD-EQs), derived by bioassay (ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells), were greatest in Cat Island samples. Cytochrome P450-associated monooxygenases and cytochrome P450 proteins were related to TEQs and TCDD-EQs; adjusted r-2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data extend previous observations in heron embryos of an association between P450 and total PCB burdens to include Ah-active PCB congeners, and presumably other compounds, which interact similarly with the Ah receptor. Benzyloxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase, and cytochrome P450 1A appear to be the most reliable measures of exposure to Ah-active PCB congeners in black-crowned night-heron embryos. These findings provide further evidence that cytochrome P450-associated parameters have considerable value as a biomarker for assessing environmental contamination of wetlands.

  18. TESTS OF GENERAL RELATIVITY IN THE STRONG-GRAVITY REGIME BASED ON X-RAY SPECTROPOLARIMETRIC OBSERVATIONS OF BLACK HOLES IN X-RAY BINARIES

    SciTech Connect

    Krawczynski, Henric

    2012-08-01

    Although general relativity (GR) has been tested extensively in the weak-gravity regime, similar tests in the strong-gravity regime are still missing. In this paper, we explore the possibility to use X-ray spectropolarimetric observations of black holes in X-ray binaries to distinguish between the Kerr metric and the phenomenological metrics introduced by Johannsen and Psaltis (which are not vacuum solutions of Einstein's equation) and thus to test the no-hair theorem of GR. To this end, we have developed a numerical code that calculates the radial brightness profiles of accretion disks and parallel transports the wave vector and polarization vector of photons through the Kerr and non-GR spacetimes. We used the code to predict the observational appearance of GR and non-GR accreting black hole systems. We find that the predicted energy spectra and energy-dependent polarization degree and polarization direction do depend strongly on the underlying spacetime. However, for large regions of the parameter space, the GR and non-GR metrics lead to very similar observational signatures, making it difficult to observationally distinguish between the two types of models.

  19. Relation of Childhood Sexual Abuse, Intimate Partner Violence, and Depression to Risk Factors for HIV Among Black Men Who Have Sex With Men in 6 US Cities

    PubMed Central

    Wilton, Leo; Magnus, Manya; Wang, Lei; Wang, Jing; Dyer, Typhanye Penniman; Koblin, Beryl A.; Hucks-Ortiz, Christopher; Fields, Sheldon D.; Shoptaw, Steve; Stephenson, Rob; O’Cleirigh, Conall; Cummings, Vanessa

    2015-01-01

    Objectives. We assessed the relation of childhood sexual abuse (CSA), intimate partner violence (IPV), and depression to HIV sexual risk behaviors among Black men who have sex with men (MSM). Methods. Participants were 1522 Black MSM recruited from 6 US cities between July 2009 and December 2011. Univariate and multivariable logistic regression models were used. Results. Participants reported sex before age 12 years with someone at least 5 years older (31.1%), unwanted sex when aged 12 to 16 years (30%), IPV (51.8%), and depression (43.8%). Experiencing CSA when aged 12 to 16 years was inversely associated with any receptive condomless anal sex with a male partner (adjusted odds ratio [AOR] = 0.50; 95% confidence interval [CI] = 0.29, 0.86). Pressured or forced sex was positively associated with any receptive anal sex (AOR = 2.24; 95% CI = 1.57, 3.20). Experiencing CSA when younger than 12 years, physical abuse, emotional abuse, having been stalked, and pressured or forced sex were positively associated with having more than 3 male partners in the past 6 months. Among HIV-positive MSM (n = 337), CSA between ages 12 and 16 years was positively associated with having more than 3 male partners in the past 6 months. Conclusions. Rates of CSA, IPV, and depression were high, but associations with HIV sexual risk outcomes were modest. PMID:26469666

  20. Spatial variability of soil organic carbon in relation to environmental factors of a typical small watershed in the black soil region, northeast China.

    PubMed

    Jian-Bing, Wei; Du-Ning, Xiao; Xing-Yi, Zhang; Xiu-Zhen, Li; Xiao-Yu, Li

    2006-10-01

    A total of 292 soil samples were taken from surface soil (0-20 cm) of a typical small watershed-Tongshuang in the black soil region of Heilongjiang province, northeast China in June 2005 for examining the concentration of soil organic carbon (SOC). Spatial variability of SOC in relation to topography and land use was evaluated using classical statistics, geostatistics and geographic information system (GIS) analyses. The objective of this study was to provide a scientific basis for land management targeting at improving soil quality in this region. Classical statistical analysis results indicated that the variability of SOC was moderate (C (V) = 0.30). Slope position and land use types were discriminating factors for its spatial variability. Geostatistics analyses showed that SOC had a strong spatial autocorrelation, which was mainly induced by structural factors. Mean concentration of SOC in surface soil was 2.27% in this watershed, which was a very low level in the northern black soil region of northeast China. In this small watershed, present soil and water conservation measures played an important role in controlling soil loss. But SOC's restoration was unsatisfactory. Nearly three-quarters of the area had worrisome productivity. How to improve SOC concentration targeting at soil fertility is a pressing need in the future.

  1. A LOCAL BASELINE OF THE BLACK HOLE MASS SCALING RELATIONS FOR ACTIVE GALAXIES. II. MEASURING STELLAR VELOCITY DISPERSION IN ACTIVE GALAXIES

    SciTech Connect

    Harris, Chelsea E.; Bennert, Vardha N.; Auger, Matthew W.; Treu, Tommaso; Woo, Jong-Hak; Malkan, Matthew A. E-mail: mauger@physics.ucsb.edu E-mail: vbennert@calpoly.edu E-mail: malkan@astro.ucla.edu

    2012-08-01

    We derive spatially resolved stellar kinematics for a sample of 84 out of 104 observed local (0.02 < z < 0.09) galaxies hosting type-1 active galactic nuclei (AGNs), based on long-slit spectra obtained at the 10 m W. M. Keck-1 Telescope. In addition to providing central stellar velocity dispersions, we measure major axis rotation curves and velocity dispersion profiles using three separate wavelength regions, including the prominent Ca H and K, Mg Ib, and Ca II NIR stellar features. In this paper, we compare kinematic measurements of stellar velocity dispersion obtained for different apertures, wavelength regions, and signal-to-noise ratios, and provide recipes to cross-calibrate the measurements reducing systematic effects to the level of a few percent. We also provide simple recipes based on readily observable quantities such as global colors and Ca H and K equivalent width that will allow observers of high-redshift AGN hosts to increase the probability of obtaining reliable stellar kinematic measurements from unresolved spectra in the region surrounding the Ca H and K lines. In subsequent papers in this series, we will combine this unprecedented spectroscopic data set with surface photometry and black hole mass measurements to study in detail the scaling relations between host galaxy properties and black hole mass.

  2. Differential accumulation of phenolic compounds and expression of related genes in black- and yellow-seeded Brassica napus.

    PubMed

    Qu, Cunmin; Fu, Fuyou; Lu, Kun; Zhang, Kai; Wang, Rui; Xu, Xinfu; Wang, Min; Lu, Junxing; Wan, Huafang; Zhanglin, Tang; Li, Jiana

    2013-07-01

    Developing yellow-seeded Brassica napus (rapeseed) with improved qualities is a major breeding goal. The intermediate and final metabolites of the phenylpropanoid and flavonoid pathways affect not only oil quality but also seed coat colour of B. napus. Here, the accumulation of phenolic compounds was analysed in the seed coats of black-seeded (ZY821) and yellow-seeded (GH06) B. napus. Using toluidine blue O staining and liquid chromatography-mass spectrometry, histochemical and biochemical differences were identified in the accumulation of phenolic compounds between ZY821 and GH06. Two and 13 unique flavonol derivatives were detected in ZY821 and GH06, respectively. Quantitative real-time PCR analysis revealed significant differences between ZY821 and GH06 in the expression of common phenylpropanoid biosynthetic genes (BnPAL and BnC4H), common flavonoid biosynthetic genes (BnTT4 and BnTT6), anthocyanin- and proanthocyandin-specific genes (BnTT3 and BnTT18), proanthocyandin-specific genes (BnTT12, BnTT10, and BnUGT2) and three transcription factor genes (BnTTG1, BnTTG2, and BnTT8) that function in the flavonoid biosynthetic pathway. These data provide insight into pigment accumulation in B. napus, and serve as a useful resource for researchers analysing the formation of seed coat colour and the underlying regulatory mechanisms in B. napus.

  3. Relations of zoned pegmatites to other pegmatites, granite, and metamorphic rocks in the southern Black Hills, South Dakota

    USGS Publications Warehouse

    Norton, J.J.; Redden, J.A.

    1990-01-01

    The pegmatite field and the Harney Peak Granite of the southern Black Hills, South Dakota, form an igneous system that progresses from slightly biotitic muscovite granite through layered pegmatitic granite, with alternating sodic and potassic rocks, to simple plagioclase-quartz-perthite pegmatites, and on to zoned pegmatites. Most of the country rocks are Lower Proterozoic mica schists. At 1700 Ga, intrusion of the Harney Peak Granite created a large dome in these rocks, a thermal aureole with a staurolite, a first sillimanite isograd, and a small area of metamorphism above the second sillimanite isograd. The zoned pegmatites have a strong tendency to occur in clusters, and the types of pegmatites are different in different clusters. A less obvious tendency is a regional zonation in which rare-mineral pegmatites become more abundant and muscovite pegmatites less abundant toward the outskirts of the region. The composition of the granite indicates that its magma originated by partial melting of metasedimentary mica schists similar to those at the present surface. The pegmatitic nature of most of the granite probably reflects exsolution of an aqueous phase. -from Authors

  4. Morphology and chemical composition relation of Rapana thomasiana shell sampled from the Romanian Coast of the Black Sea

    NASA Astrophysics Data System (ADS)

    Sereanu, Viviana; Meghea, Irina; Vasile, Gabriela; Simion, Marius; Mihai, Mihaela

    2016-09-01

    Rapana thomasiana is a predatory gastropod and a successful invader, which is found in abundance in the Black Sea. The aim of this study is to determine whether there is a relationship between morphology and chemical composition of rapana shell and therefore if the maturation of R. thomasiana shells, quantified by morphological parameters, has influence on their mineralization level, assessed by chemical composition analysis. For this purpose, integer individuals of R. thomasiana were collected from Limanu, Midia Cape and Vadu-Corbu beaches and morphological parameters of shells, such as length (L), mass (m), thickness (th) were investigated using specific mathematical statistic methods. Characteristic features of rapana whelk were found according to the corresponding marine substrate. Age classification was done using Bhattacharya method which has divided R. thomasiana population within three to four age-groups. In order to determine if there are significant differences between age classes in terms of chemical composition, for each determined age-group a chemical analysis was conducted. In this respect, the mineral content and total organic carbon (TOC) determined, showed in general, statistically significant differences (p<0.025 and p>0.975) among Ca, Mg and organic C values for almost all age-classes. The statistical trend suggests a slight growth of the organic matter and a drop of mineral composition with age.

  5. Investigating AGN black hole masses and the MBH-σe relation for low surface brightness galaxies

    NASA Astrophysics Data System (ADS)

    Subramanian, S.; Ramya, S.; Das, M.; George, K.; Sivarani, T.; Prabhu, T. P.

    2016-01-01

    We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of low surface brightness (LSB) galaxies. Using data from the Sloan Digital Sky Survey (SDSS), we derived the virial black hole (BH) masses of 24 galaxies from their broad Hα parameters. We find that our estimates of nuclear BH masses lie in the range 105-107 M⊙, with a median mass of 5.62 × 106 M⊙. The bulge stellar velocity dispersion σe was determined from the underlying stellar spectra. We compared our results with the existing BH mass-velocity dispersion (MBH-σe) correlations and found that the majority of our sample lie in the low BH mass regime and below the MBH-σe correlation. We analysed the effects of any systematic bias in the MBH estimates, the effects of galaxy orientation in the measurement of σe and the increase of σe due to the presence of bars and found that these effects are insufficient to explain the observed offset in MBH-σe correlation. Thus, the LSB galaxies tend to have low-mass BHs which probably are not in co-evolution with the host galaxy bulges. A detailed study of the nature of the bulges and the role of dark matter in the growth of the BHs is needed to further understand the BH-bulge co-evolution in these poorly evolved and dark matter dominated systems.

  6. Assessment of shoreline vegetation in relation to use by molting black brant Branta bernicla nigricans on the Alaska Coastal Plain

    USGS Publications Warehouse

    Weller, Milton W.; Jensen, K.C.; Taylor, Eric J.; Miller, Mark W.; Bollinger, Karen S.; Derksen, Dirk V.; Esler, Daniel N.; Markon, Carl J.

    1994-01-01

    To evaluate the importance of large thaw lakes on the Alaska Coastal Plain for molting Pacific black brant Branta bernicla nigricans, distribution and life form of shoreline vegetation were assessed using several scales: satellite imagery, point-intercept transects, cover quadrats, and a parameter for water regime. Brant population and distribution estimates from aerial surveys were used to classify large lakes into high, moderate, and low use. Correlations between brant and abundance of their preferred feeding site - moss flats - were best demonstrated by satellite imagery. Intercepts and cover ratings were not correlated, presumably because these techniques were less efficient at assessing area. General observations suggested that the presence of islands, large ice floes, and possibly other physical attributes of the habitat, influenced brant distribution. This area is unique because of low-lying, drained-lake basins that have ideal combinations of moss flats and large water areas where brant seek protection disturbance is vital to the success of this declining species because alternate habitats may not be available elsewhere on the Coastal Plain. in water or on ice floes. Protection of the area from disturbance is vital to the success of this declining species because alternate habitats may not be available elsewhere on the Coastal Plain.

  7. Germinated Thai Black Rice Extract Protects Experimental Diabetic Rats from Oxidative Stress and Other Diabetes-Related Consequences

    PubMed Central

    Chaiyasut, Chaiyavat; Sivamaruthi, Bhagavathi Sundaram; Pengkumsri, Noppawat; Keapai, Waranya; Kesika, Periyanaina; Saelee, Manee; Tojing, Parichart; Sirilun, Sasithorn; Chaiyasut, Khontaros; Peerajan, Sartjin; Lailerd, Narissara

    2016-01-01

    Background: Diabetes mellitus (DM), particularly type 2 DM (T2DM), is one of the most common metabolic disorder worldwide. The prevention measures and treatment strategies for DM are improving steadily. The current study explains the impact of germination on phytochemical content of Thai black rice (BR), and the influence of germinated BR extract (GBRE) supplementation on diabetic conditions in rats. Methods: BR was germinated and the phenolic, anthocyanin, and γ-aminobutyric acid (GABA) content of the extract were analyzed using HPLC and spectrophotometric methods. Streptozotocin-induced diabetic rats were supplemented with high and low doses of GBRE. The plasma glucose, insulin, cholesterol, triglyceride levels, antioxidant status, and antioxidant enzyme levels of treated animals were assessed using ELISA and spectrophotometric methods. Results: Germination enhanced the GABA content of BR, and GBRE intervention improved the total antioxidant capacity and antioxidant enzymes levels in diabetic rats. The plasma glucose, cholesterol, triglyceride levels, insulin resistance and glucose tolerance were reduced, and the degree of insulin secretion in rat plasma was significantly increased upon GBRE treatment. Both pre and post-treatment approaches showed the anti-diabetic ability of GBRE. In most of the analyzed parameters, GBRE was quite equal to the performance of drug-metformin. Conclusions: GBRE supplementation helps prevent and manage the consequences of DM. PMID:28036014

  8. Differential accumulation of phenolic compounds and expression of related genes in black- and yellow-seeded Brassica napus

    PubMed Central

    Qu, Cunmin; Fu, Fuyou; Lu, Kun; Zhang, Kai; Wang, Rui; Xu, Xinfu; Wang, Min; Lu, Junxing; Wan, Huafang; Zhanglin, Tang; Li, Jiana

    2013-01-01

    Developing yellow-seeded Brassica napus (rapeseed) with improved qualities is a major breeding goal. The intermediate and final metabolites of the phenylpropanoid and flavonoid pathways affect not only oil quality but also seed coat colour of B. napus. Here, the accumulation of phenolic compounds was analysed in the seed coats of black-seeded (ZY821) and yellow-seeded (GH06) B. napus. Using toluidine blue O staining and liquid chromatography–mass spectrometry, histochemical and biochemical differences were identified in the accumulation of phenolic compounds between ZY821 and GH06. Two and 13 unique flavonol derivatives were detected in ZY821 and GH06, respectively. Quantitative real-time PCR analysis revealed significant differences between ZY821 and GH06 in the expression of common phenylpropanoid biosynthetic genes (BnPAL and BnC4H), common flavonoid biosynthetic genes (BnTT4 and BnTT6), anthocyanin- and proanthocyandin-specific genes (BnTT3 and BnTT18), proanthocyandin-specific genes (BnTT12, BnTT10, and BnUGT2) and three transcription factor genes (BnTTG1, BnTTG2, and BnTT8) that function in the flavonoid biosynthetic pathway. These data provide insight into pigment accumulation in B. napus, and serve as a useful resource for researchers analysing the formation of seed coat colour and the underlying regulatory mechanisms in B. napus. PMID:23698630

  9. Unemployment among Black Youths, Demographics, and Crime.

    ERIC Educational Resources Information Center

    Calvin, Allen D.

    1981-01-01

    Erroneous conclusions relating to the interrelationship among unemployment rates, demographics, and crime rates of Black youths are discussed. A reexamination of the data shows that crime by Black youths bears a close relationship with prevailing economic conditions. (Author/RC)

  10. Teaching the Black Experience.

    ERIC Educational Resources Information Center

    Kirschenbaum, Howard

    1968-01-01

    Instructional materials and teaching approaches can be used to get students to seriously and constructively confront problems in race relations which they will eventually have to solve. For example, Richard Wright's "Black Boy," an anthology of Negro poetry or a collection of poems on race relations, and such films as "Where is Prejudice?" can…

  11. Fidelity and breeding probability related to population density and individual quality in black brent geese Branta bernicla nigricans

    USGS Publications Warehouse

    Sedinger, J.S.; Chelgren, N.D.; Ward, D.H.; Lindberg, M.S.

    2008-01-01

    1. Patterns of temporary emigration (associated with non-breeding) are important components of variation in individual quality. Permanent emigration from the natal area has important implications for both individual fitness and local population dynamics. 2. We estimated both permanent and temporary emigration of black brent geese (Branta bernicla nigricans Lawrence) from the Tutakoke River colony, using observations of marked brent geese on breeding and wintering areas, and recoveries of ringed individuals by hunters. We used the likelihood developed by Lindberg, Kendall, Hines & Anderson 2001 (Combining band recovery data and Pollock's robust design to model temporary and permanent emigration. Biometrics, 57, 273-281) to assess hypotheses and estimate parameters. 3. Temporary emigration (the converse of breeding) varied among age classes up to age 5, and differed between individuals that bred in the previous years vs. those that did not. Consistent with the hypothesis of variation in individual quality, individuals with a higher probability of breeding in one year also had a higher probability of breeding the next year. 4. Natal fidelity of females ranged from 0.70 ?? 0.07-0.96 ?? 0.18 and averaged 0.83. In contrast to Lindberg et al. (1998), we did not detect a relationship between fidelity and local population density. Natal fidelity was negatively correlated with first-year survival, suggesting that competition among individuals of the same age for breeding territories influenced dispersal. Once females nested at the Tutakoke River, colony breeding fidelity was 1.0. 5. Our analyses show substantial variation in individual quality associated with fitness, which other analyses suggest is strongly influenced by early environment. Our analyses also suggest substantial interchange among breeding colonies of brent geese, as first shown by Lindberg et al. (1998).

  12. Microorganisms and typical organic matter responsible for lacustrine "black bloom".

    PubMed

    Feng, Ziyan; Fan, Chengxin; Huang, Weiyi; Ding, Shiming

    2014-02-01

    Identifying the causation of the black substance in lacustrine "black bloom" is of great significance for forecasting and preventing black bloom in many waters of the world. In this research, an array of black bloom was simulated in a laboratory to investigate how microorganisms and organic matter affect black bloom. Sulphate-reducing bacteria (SRB) are the main biological factor, and protein is the key organic factor contributing to lacustrine black bloom. The black colour of black bloom is strongly associated with a relatively high SRB population density. Hydrogen sulphide concentration can serve as a predictor of black bloom.

  13. Genome-wide association study for carcass traits, fatty acid composition, chemical composition, sugar, and the effects of related candidate genes in Japanese Black cattle.

    PubMed

    Sasago, Nanae; Abe, Tsuyoshi; Sakuma, Hironori; Kojima, Takatoshi; Uemoto, Yoshinobu

    2017-01-01

    We performed a genome-wide association study (GWAS) and candidate gene analysis to: (i) evaluate the effectiveness of the GWAS in our small population by performing GWAS for carcass weight (CW) and fatty acid composition; (ii) detect novel candidate regions affecting non-CW carcass traits, chemical composition and sugar; and (iii) evaluate the association of the candidate genes previously detected in CW and fatty acid composition with other economically important traits. A total of 574 Japanese Black cattle and 40 657 Single nucleotide polymorphisms were used. In addition, candidate gene analyses were performed to evaluate the association of three CW-related genes and two fatty acid-related genes with carcass traits, fatty acid composition, chemical composition and sugar. The significant regions with the candidate genes were detected for CW and fatty acid composition, and these results showed that a significant region would be detectable despite the small sample size. The novel candidate regions were detected on BTA23 for crude protein and on BTA19 for fructose. CW-related genes associated with the rib-eye area and fatty acid composition were identified, and fatty acid-related genes had no relationship with other traits. Moreover, the favorable allele of CW-related genes had an unfavorable effect on fatty acid composition.

  14. Milankovitch climate cyclicity and its effect on relative sea level changes and organic carbon storage, Late Cretaceous black shales of Colombia and Venezuela

    SciTech Connect

    Villamil, T.; Kauffman, E.G. )

    1993-02-01

    The Late Cretaceous Villeta Group and La Luna Formation shows remarkable depositional cyclicity attributable to Milankovitch climate cycles. Each 30-60 cm thick hemicycle is composed of a basal gray shale, a medial black, organic-rich shale, and an upper gray shale with a dense argillaceous limestone cap. Fourier time-series analysis revealed peak frequencies of 500, 100, and 31 ka (blending 21 and 42 ka data). ThiS cyclicity reflects possibly wet cooler (shale) to dry, possibly warm (limestone) climatic changes and their influence on relative sea level, sedimentation rates/patterns, productivity, water chemistry and stratification. Wet/cool hemicycles may produce slight lowering of sealevel, increased rates of clay sedimentation, diminished carbonate production, water stratification, increased productivity among noncalcareous marine plankton, and increased Corg production and storage. Dry/warm hemicycles may produce a slight rise in sealevel, and return to normal marine conditions with low Corg storage. Source rock quality may depend upon the predominance of wet over dry climatic phases. Differences between climate-forced cyclicity and random facies repetition, are shown by contrasting observed lithological patterns and geochemical signals with litho- and chemostratigraphy generated from random models. Accomodation space plots (Fischer plots) for cyclically interbedded black shale-pelagic limestone sequences, allowed prediction of facies behavior, shoreline architecture, and quantitative analysis of relative sea level. The synchroneity of Milankovitch cycles and changes in hemicycle stacking patterns, were tested against a new high-resolution event-chronostratigraphic and biostratigraphic framework for NW South America. Geochemical spikes and hemicycle stacking patterns occur consistently throughout the sections measured, supporting the correlation potential of cyclostratigraphy.

  15. Signal enhancement in electrospray laser desorption/ionization mass spectrometry by using a black oxide-coated metal target and a relatively low laser fluence.

    PubMed

    Kononikhin, Alexey; Huang, Min-Zong; Popov, Igor; Kostyukevich, Yury; Kukaev, Evgeny; Boldyrev, Alexey; Spasskiy, Alexander; Leypunskiy, Ilya; Shiea, Jentaie; Nikolaev, Eugene

    2013-01-01

    The electrospray Laser desorption/ionization (ELDI) method is actively used for direct sample analysis and ambient mass spectrometry imaging. The optimizing of Laser desorption conditions is essential for this technology. In this work, we propose using a metal target with a black oxide (Fe3O4) coating to increase the signal in ELDI-MS for peptides and small proteins. The experiments were performed on an LTQ-FT mass spectrometer equipped with a home-made ELDI ion source. A cutter blade with black oxide coating was used as a target. A nitrogen laser was used with the following parameters: 337 nm, pulse duration 4ns, repetition rate 10 Hz, fluence to approximately 700 Jm(-2). More than a five times signal increase was observed for a substance P peptide when a coated and a non-coated metal target were compared. No ion signal was observed for proteins if the same fluence and the standard stainless steel target were used. With the assistance of the Fe3O4 coated metal target and a relatively low laser fluence < or =700 Jm(-2)), proteins such as insulin, ubiquitin and myoglobin were successfully ionized. It was demonstrated that the Fe3O4-coated metal target can be used efficiently to assist laser desorption and thus significantly increase the analyte signal in ELDI-MS. A relatively low laser fluence (< or = 700 Jm(-2)) was enough to desorb peptides and proteins (up to 17 kDal with the assistance of the Fe3O4-coated metal target under ambient conditions.

  16. Sleeping sites, sleeping trees, and sleep-related behaviors of black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Central Yunnan, China.

    PubMed

    Fan, Peng-Fei; Jiang, Xue-Long

    2008-02-01

    Data on sleep-related behaviors were collected for a group of central Yunnan black crested gibbons (Nomascus concolor jingdongensis) at Mt. Wuliang, Yunnan, China from March 2005 to April 2006. Members of the group usually formed four sleeping units (adult male and juvenile, adult female with one semi-dependent black infant, adult female with one dependent yellow infant, and subadult male) spread over different sleeping trees. Individuals or units preferred specific areas to sleep; all sleeping sites were situated in primary forest, mostly (77%) between 2,200 and 2,400 m in elevation. They tended to sleep in the tallest and thickest trees with large crowns on steep slopes and near important food patches. Factors influencing sleeping site selection were (1) tree characteristics, (2) accessibility, and (3) easy escape. Few sleeping trees were used repeatedly by the same or other members of the group. The gibbons entered the sleeping trees on average 128 min before sunset and left the sleeping trees on average 33 min after sunrise. The lag between the first and last individual entering the trees was on average 17.8 min. We suggest that sleep-related behaviors are primarily adaptations to minimize the risk of being detected by predators. Sleeping trees may be chosen to make approach and attack difficult for the predator, and to provide an easy escape route in the dark. In response to cold temperatures in a higher habitat, gibbons usually sit and huddle together during the night, and in the cold season they tend to sleep on ferns and/or orchids.

  17. Merging Black Holes

    NASA Technical Reports Server (NTRS)

    Centrella, John

    2009-01-01

    The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GEO600, as well as the space-based LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

  18. Merging Black Holes

    NASA Astrophysics Data System (ADS)

    Centrella, Joan

    2009-05-01

    The final merger of two black holes is expected to be the strongest gravitational wave source for ground-based interferometers such as LIGO, VIRGO, and GEO600, as well as the space-based LISA. Observing these sources with gravitational wave detectors requires that we know the radiation waveforms they emit. And, when the black holes merge in the presence of gas and magnetic fields, various types of electromagnetic signals may also be produced. Since these mergers take place in regions of extreme gravity, we need to solve Einstein's equations of general relativity on a computer. For more than 30 years, scientists have tried to compute black hole mergers using the methods of numerical relativity. The resulting computer codes have been plagued by instabilities, causing them to crash well before the black holes in the binary could complete even a single orbit. Within the past few years, however, this situation has changed dramatically, with a series of remarkable breakthroughs. This talk will focus on new simulations that are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics.

  19. Characterizing Black Hole Mergers

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

    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.

  20. Feasibility study to develop a marketing plan and strategy for increasing the participation of minority business enterprises and black colleges and universities in energy-related industries

    SciTech Connect

    Not Available

    1983-01-31

    This study was designed to identify and test an alternative method for more effective means of involving Minority Business Enterprises (MBEs) and historically Black colleges and universities (HBCUs) in energy-related business opportunities. Based upon the analysis of MBE and HBCU technical assistance programs, DOD's, DOE's, and TVA's procurement processes and the results of the test used to validate the adaptability of a performance tested alternative marketing system to energy-related industries. Based on the findings and conclusions of this study and in order to meet the objectives of: (1) increasing participation of MBEs and HBCUs in TVA and energy-related industries; (2) ensuring that the statutory objectives of Title VI of the Civil Rights Act of 1964 and Public Law 95-507 are achieved in the public and private energy market sectors; and (3) meeting President Reagan's goal of realizing $22 billion in minority contracts within the next three years, BTW recommends that the Portfolio System be adapted, demonstrated, installed and deployed in large-scale, complex, energy-related research and development facilities and power utilities' procurement programs.

  1. Merging Black Holes

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2012-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as future. space-based detectors. Since the merger takes place in the regime of strong dynamical gravity, computing the resulting gravitational waveforms requires solving the full Einstein equations of general relativity on a computer. For many years, numerical codes designed to simulate black hole mergers were plagued by a host of instabilities. However, recent breakthroughs have conquered these instabilities and opened up this field dramatically. This talk will focus on.the resulting 'gold rush' of new results that is revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wave detection, testing general relativity, and astrophysics

  2. Merging Black Holes

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2010-01-01

    The final merger of two black holes is expected to be the strongest source of gravitational waves for both ground-based detectors such as LIGO and VIRGO, as well as the space-based LISA. 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 are revealing the dynamics and waveforms of binary black hole mergers, and their applications in gravitational wove detection, testing general relativity, and astrophysics.

  3. Black raspberry: Korean vs. American

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This fact sheet shows Korean black raspberry (Rubus coreanus) fruit, flower, and leaf features that distinguish them from their Rubus relatives, black raspberry (R. occidentalis) native to America. Common names with fruit characteristics, including berry size and pigment fingerprints, are summarized...

  4. Whites' Beliefs about Blacks' Opportunity.

    ERIC Educational Resources Information Center

    Kluegel, James R.; Smith, Eliot R.

    1982-01-01

    Cites data which show that Whites tend to perceive widespread reverse discrimination, to see Blacks' opportunities as having greatly improved in recent years, and to deny structural limits to Black opportunity. Posits that these perceptions are related to (1) prevailing public beliefs about stratification and (2) peoples' own social positions and…

  5. Health Policies and Black Americans.

    ERIC Educational Resources Information Center

    Willis, David P., Ed.

    This collection of essays focuses on the impact of health policy on black Americans by examining the relation between public policy and the distribution of health needs and effects. The book includes an introduction by David P. Willis and is divided into seven sections. Section I, "Who Are Black Americans?" includes the following…

  6. Associations between HIV-related stigma, racial discrimination, gender discrimination, and depression among HIV-positive African, Caribbean, and Black women in Ontario, Canada.

    PubMed

    Logie, Carmen; James, Llana; Tharao, Wangari; Loutfy, Mona

    2013-02-01

    Abstract African, Caribbean, and Black (ACB) women are greatly overrepresented in new HIV infections in comparison with Canada's general population. Social and structural factors such as HIV-related stigma, gender discrimination, and racial discrimination converge to increase vulnerability to HIV infection among ACB women by reducing access to HIV prevention services. Stigma and discrimination also present barriers to treatment, care, and support and may contribute to mental health problems. We administered a cross-sectional survey to HIV-positive ACB women (n=173) across Ontario in order to examine the relationships between HIV-related stigma, gender discrimination, racial discrimination, and depression. One-third of participants reported moderate/severe depression scores using the Beck Depression Inventory Fast-Screen guidelines. Hierarchical block regression, moderation, and mediation analyses were conducted to measure associations between independent (HIV-related stigma, gender discrimination, racial discrimination), moderator/mediator (social support, resilient coping), and dependent (depression) variables. Findings included: (1) HIV-related stigma was associated with increased depression; (2) resilient coping was associated with reduced depression but did not moderate the influence of HIV-related stigma on depression; and (3) the effects of HIV-related stigma on depression were partially mediated through resilient coping. HIV-related stigma, gender discrimination, and racial discrimination were significantly correlated with one another and with depression, highlighting the salience of examining multiple intersecting forms of stigma. Generalizability of findings may be limited due to nonrandom sampling. Findings emphasize the importance of multi-component interventions, including building resilient coping skills, mental health promotion and assessment, and stigma reduction programs.

  7. Association of the expression levels in the skeletal muscle and a SNP in the CDC10 gene with growth-related traits in Japanese Black beef cattle.

    PubMed

    Tong, B; Li, G P; Sasaki, S; Muramatsu, Y; Ohta, T; Kose, H; Yamada, T

    2015-04-01

    Growth performance, as well as marbling, is the main breeding objective in Japanese Black (JB) cattle, the major beef breed in Japan. The septin 7 (CDC10) gene, involved in cellular proliferation, is located within a genomic region of a quantitative trait locus for growth-related traits. In this study, we first showed that the expression levels of the CDC10 gene in the skeletal muscle were higher in JB steers with extremely high growth performance than in JB steers with extremely low growth, using real-time PCR. Further, a single nucleotide polymorphism (SNP), NC_007302.5:g.63264949G>C, was detected in the promoter region of the CDC10 gene and genotyped in three Japanese cattle breeds (known as 'Wagyu' in Japan) and the Brown Swiss dairy cattle breed. All four cattle populations showed a moderate genetic diversity at the SNP of the CDC10 gene. An association analysis indicated that the SNP was associated with growth-related traits in JB cattle. These findings suggest possible effects of the expression levels in the skeletal muscle and the SNP of the CDC10 gene on growth-related traits in JB cattle. The CDC10 SNP may be useful for effective marker-assisted selection to increase beef productivity in JB beef cattle.

  8. Hidden Structures of Black Holes

    NASA Astrophysics Data System (ADS)

    Vercnocke, Bert

    2010-11-01

    This thesis investigates two main topics concerning black holes in extensions of general relativity inspired by string theory. First, the structure of the equations of motion underlying black hole solutions is considered, in theories of D-dimensional gravity coupled to scalars and vectors. For solutions preserving supersymmetry, the equations of motion have a dramatic simplification: they become first-order instead of the second-order equations one would expect. Recently, it was found that this is a feature some non-supersymmetric black hole solutions exhibit as well. We investigate if this holds more generally, by examining what the conditions are to have first-order equations for the scalar fields of non-supersymmetric black holes, that mimic the form of their supersymmetric counterparts. This is illustrated in examples. Second, the structure of black holes themselves is investigated. String theory has been successful in explaining the Bekenstein-Hawking entropy for (mainly supersymmetric) black holes from a microscopic perspective. However, it is not fully established what the interpretation of the corresponding 'microstates' should be in the gravitational description where the black hole picture is valid. There have been recent advances to understand the nature of black hole microstates in the gravity regime, such as the fuzzball proposal. A related idea says that black hole configurations with multiple centers are related to microstates of single-centered black holes. We report on work relating both pictures. As an aside, a relation between violations of causality for certain spacetimes (presence of closed timelike curves in the geometry) and a breakdown of unitarity in the dual conformal field theory is given.

  9. Future Directions in Research on Racism-Related Stress and Racial-Ethnic Protective Factors for Black Youth.

    PubMed

    Jones, Shawn C T; Neblett, Enrique W

    2016-05-04

    Research on racism-related stress and racial-ethnic protective factors represents an important enterprise for optimizing the mental health of African American and other racial and ethnic minority youth. However, there has been a relative dearth of work on these factors in the clinical psychology research literature, and more work is needed in outlets such as these. To this end, the current article adopts a developmental psychopathology framework and uses recent empirical findings to outline our current understanding of racism-related stress and racial-ethnic protective factors (i.e., racial identity, racial socialization, Africentric worldview) for African American youth. We then provide nine recommendations-across basic, applied, and broader/cross-cutting research lines-that we prioritize as essential to advancing the future scientific investigation of this crucial research agenda. Within and across these recommendations, we issue a charge to researchers and clinicians alike, with the ultimate goal of alleviating the negative mental health impact that racism-related stress can have on the well-being and mental health of African American and other racial and ethnic minority youth.

  10. Relations Among Maternal Racial Identity, Maternal Parenting Behavior, and Child Outcomes in Low-Income, Urban, Black Families

    ERIC Educational Resources Information Center

    Halgunseth, Linda C.; Ispa, Jean M.; Csizmadia, Annamaria; Thornburg, Kathy R.

    2005-01-01

    This study examined maternal racial identity and its relations to maternal depression, maternal age, maternal parenting behavior, and 5-year-old children's social and cognitive outcomes. Participants included 62 African American mother-child dyads enrolled in the Early Head Start Research and Evaluation Project. Mothers completed measures on their…

  11. African (Black) Psychology: Issues and Synthesis.

    ERIC Educational Resources Information Center

    Baldwin, Joseph A.

    1986-01-01

    Reviews the recent attempts of Black psychologists and social scientists to formulate a conceptual-operational framework for the study of psychological phenomena as they bear on the cultural-survival conditions of Black-African people. Outlines issues and problems in the attempt to define African (Black) psychology and discusses its relation to…

  12. The Family Hero in Black Alcoholism Families.

    ERIC Educational Resources Information Center

    Brisbane, Francis L.

    1989-01-01

    Uses data from 20 case studies of Black adult female children of alcoholic parents to discuss Family Hero role often assumed by oldest or only female child in Black alcoholism families. Explains how female-dominated survival role of Family Hero in Black families is significantly more related to racial and cultural factors than numbers alone may…

  13. Black Task Force Report: Project on Ethnicity.

    ERIC Educational Resources Information Center

    Delaney, Anita J., Ed.

    The major aim of this report is to develop a model of mental health service delivery to the urban, low-income black community. The model assumes that racism and poverty have placed constraints on the development and functioning of systems related to the black family and that the family is the primary source of mental health in the black community.…

  14. Two Views of Black and White Swimmers

    ERIC Educational Resources Information Center

    McClure, John W.

    1972-01-01

    Examines the nature-nurture question particularly in relation to body density and attitude of black and white swimmers. No claim is made to posing a definitive answer to the problems facing the prospective black swimmer, but it is contended that many black students can succeed in the water if a positive climate for learning is established. (SB)

  15. Numerical Simulation of Black Holes

    NASA Astrophysics Data System (ADS)

    Teukolsky, Saul

    2003-04-01

    Einstein's equations of general relativity are prime candidates for numerical solution on supercomputers. There is some urgency in being able to carry out such simulations: Large-scale gravitational wave detectors are now coming on line, and the most important expected signals cannot be predicted except numerically. Problems involving black holes are perhaps the most interesting, yet also particularly challenging computationally. One difficulty is that inside a black hole there is a physical singularity that cannot be part of the computational domain. A second difficulty is the disparity in length scales between the size of the black hole and the wavelength of the gravitational radiation emitted. A third difficulty is that all existing methods of evolving black holes in three spatial dimensions are plagued by instabilities that prohibit long-term evolution. I will describe the ideas that are being introduced in numerical relativity to deal with these problems, and discuss the results of recent calculations of black hole collisions.

  16. Differential effects of stress and African ancestry on preterm birth and related traits among US born and immigrant Black mothers

    PubMed Central

    Tsai, Hui-Ju; Surkan, Pamela J.; Yu, Stella M.; Caruso, Deanna; Hong, Xiumei; Bartell, Tami R.; Wahl, Anastacia D.; Sampankanpanich, Claire; Reily, Anne; Zuckerman, Barry S.; Wang, Xiaobin

    2017-01-01

    Abstract Preterm birth (PTB, <37 weeks of gestation) is influenced by a wide range of environmental, genetic and psychosocial factors, and their interactions. However, the individual and joint effects of genetic factors and psychosocial stress on PTB have remained largely unexplored among U.S. born versus immigrant mothers. We studied 1121 African American women from the Boston Birth Cohort enrolled from 1998 to 2008. Regression-based analyses were performed to examine the individual and joint effects of genetic ancestry and stress (including lifetime stress [LS] and stress during pregnancy [PS]) on PTB and related traits among U.S. born and immigrant mothers. Significant associations between LS and PTB and related traits were found in the total study population and in immigrant mothers, including gestational age, birthweight, PTB, and spontaneous PTB; but no association was found in U.S. born mothers. Furthermore, significant joint associations of LS (or PS) and African ancestral proportion (AAP) on PTB were found in immigrant mothers, but not in U.S. born mothers. Although, overall, immigrant women had lower rates of PTB compared to U.S. born women, our study is one of the first to identify a subset of immigrant women could be at significantly increased risk of PTB and related outcomes if they have high AAP and are under high LS or PS. In light of the growing number of immigrant mothers in the U.S., our findings may have important clinical and public health implications. PMID:28151865

  17. Merging Black Holes

    NASA Technical Reports Server (NTRS)

    Centrella, Joan; Baker, John G.; Kelly, Bernard J.; vanMeter, James R.

    2010-01-01

    Black-hole mergers take place in regions of very strong and dynamical gravitational fields, and are among the strongest sources of gravitational radiation. Probing these mergers requires solving the full set of Einstein's equations of general relativity numerically. For more than 40 years, progress towards this goal has been very slow, as numerical relativists encountered a host of difficult problems. Recently, several breakthroughs have led to dramatic progress, enabling stable and accurate calculations of black-hole mergers. This article presents an overview of this field, including impacts on astrophysics and applications in gravitational wave data analysis.

  18. An Examination of Black Male First-Generation College Students' Reports of the Social Supports that Have Buffering Effects on Their School-Related Stress and Help Them Achieve Academic Success in College

    ERIC Educational Resources Information Center

    Harrington, Anthony C.

    2011-01-01

    The purpose of this exploratory, case study of Black male first-generation college students at Carthen College was three-fold. First, it was designed to elicit participants' descriptions of the stress they experienced related to school and being a student. Second, the study aimed to describe and then rate how important that source of support was…

  19. Noncommutative black hole thermodynamics

    SciTech Connect

    Banerjee, Rabin; Majhi, Bibhas Ranjan; Samanta, Saurav

    2008-06-15

    We give a general derivation, for any static spherically symmetric metric, of the relation T{sub h}=(K/2{pi}) connecting the black hole temperature (T{sub h}) with the surface gravity (K), following the tunneling interpretation of Hawking radiation. This derivation is valid even beyond the semi-classical regime, i.e. when quantum effects are not negligible. The formalism is then applied to a spherically symmetric, stationary noncommutative Schwarzschild space-time. The effects of backreaction are also included. For such a black hole the Hawking temperature is computed in a closed form. A graphical analysis reveals interesting features regarding the variation of the Hawking temperature (including corrections due to noncommutativity and backreaction) with the small radius of the black hole. The entropy and tunneling rate valid for the leading order in the noncommutative parameter are calculated. We also show that the noncommutative Bekenstein-Hawking area law has the same functional form as the usual one.

  20. Polluting Black space.

    PubMed

    Bonam, Courtney M; Bergsieker, Hilary B; Eberhardt, Jennifer L

    2016-11-01

    Social psychologists have long demonstrated that people are stereotyped on the basis of race. Researchers have conducted extensive experimental studies on the negative stereotypes associated with Black Americans in particular. Across 4 studies, we demonstrate that the physical spaces associated with Black Americans are also subject to negative racial stereotypes. Such spaces, for example, are perceived as impoverished, crime-ridden, and dirty (Study 1). Moreover, these space-focused stereotypes can powerfully influence how connected people feel to a space (Studies 2a, 2b, and 3), how they evaluate that space (Studies 2a and 2b), and how they protect that space from harm (Study 3). Indeed, processes related to space-focused stereotypes may contribute to social problems across a range of domains-from racial disparities in wealth to the overexposure of Blacks to environmental pollution. Together, the present studies broaden the scope of traditional stereotyping research and highlight promising new directions. (PsycINFO Database Record

  1. Bringing Black Holes Home

    NASA Astrophysics Data System (ADS)

    Furmann, John M.

    2003-03-01

    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.

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

    PubMed

    Sutton, Madeline Y; Parks, Carolyn P

    2013-06-01

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

  3. Counseling Blacks

    ERIC Educational Resources Information Center

    Vontress, Clemmont E.

    1970-01-01

    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…

  4. Black English.

    ERIC Educational Resources Information Center

    Bailey, Charles-James N.

    This paper, presented as part of a military lecture series given by the Division of Continuing Education and Community Service Speakers' Bureau of the University of Hawaii to military personnel at Schofield Barracks and Fort Shafter, investigates the origins and present status of Black English. A discussion of early studies in the Gullah dialect…

  5. Black America.

    ERIC Educational Resources Information Center

    San Francisco Unified School District, CA.

    This is a selected bibliography of some good and some outstanding audio-visual educational materials in the library of the Educational Materials Bureau, Audio-Visual Education Section, that may be considered by particular interest in the study of black Americans. The bibliography is arranged alphabetically within these subject areas: I. African…

  6. String-Corrected Black Holes

    SciTech Connect

    Hubeny, Veronika; Maloney, Alexander; Rangamani, Mukund

    2005-02-07

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

  7. Mobilizing Black America

    DTIC Science & Technology

    1993-04-01

    birth weight . Low birth weight today is a major contributor to the high infant death rate. Low birth weight is considered as weighing less than 2,500...syndrome o Disorders relating to short gestations unspecified low birth weight o Respiratory distress syndrome The above causes of death accounted for...syndrome. Different causes of death were found in the black community; unspecified low birth weight and disorders relating to short gestation followed

  8. Cardiometabolic Biomarkers in Young Black Girls: Relations to Body Fatness and Aerobic Fitness, and Effects of a Randomized Physical Activity Trial

    PubMed Central

    Gutin, Bernard; Harris, Ryan A.; Howe, Cheryl A.; Johnson, Maribeth H.; Zhu, Haidong; Dong, Yanbin

    2011-01-01

    There is little evidence from randomized trials showing that physical activity alone influences biomarker profiles in youths. This study tested two hypotheses: (i) that elevated body fatness and poor fitness would be associated with unfavorable levels of cardiometabolic biomarkers in 8–12-y-old black girls (n = 242) and (ii) that a 10-mo PA intervention would have favorable effects on the fatness-related cardiometabolic biomarkers. At baseline, all fatness indices (i.e., percent body fat, visceral adipose tissue, BMI, and waist circumference) were significantly (P < 0.05) associated with unfavorable levels of insulin, glucose, systolic BP, diastolic BP, triglycerides, C-reactive protein (CRP), and fibrinogen. Aerobic fitness was significantly (P < 0.05) associated with favorable levels of insulin, CRP, fibrinogen, and HDL2. The PA intervention had significant and favorable effects on fitness, fatness, and two biomarkers—resting heart rate and LDL cholesterol. More research is needed to clarify what types of interventions can enhance the cardiometabolic health of youths. PMID:22007244

  9. War-Related Post-Traumatic Stress Disorder in Black, Hispanic, and Majority White Vietnam Veterans: The Roles of Exposure and Vulnerability

    PubMed Central

    Dohrenwend, Bruce P.; Turner, J. Blake; Turse, Nicholas A.; Lewis-Fernandez, Roberto; Yager, Thomas J.

    2008-01-01

    Elevated prevalence rates of chronic PTSD have been reported for Black and Hispanic Vietnam veterans. There has been no comprehensive explanation of these group differences. Moreover, previous research has relied on retrospective reports of war-zone stress and on PTSD assessments that fail to distinguish between prevalence and incidence. These limitations are addressed by use of record-based exposure measures and clinical diagnoses of a sub-sample of veterans from the National Vietnam Veterans Readjustment Study (NVVRS). Compared with majority whites, the Black elevation is explained by Blacks' greater exposure; the Hispanic elevation, by Hispanics' greater exposure, younger age, lesser education, and lower Armed Forces Qualification Test scores. PTSD elevation in Hispanics versus Blacks is accounted for mainly by Hispanics' younger age. PMID:18404630

  10. Slowly balding black holes

    SciTech Connect

    Lyutikov, Maxim; McKinney, Jonathan C.

    2011-10-15

    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{sub B}=e{Phi}{sub {infinity}}/({pi}c({h_bar}/2{pi})), where {Phi}{sub {infinity}}{approx_equal}2{pi}{sup 2}B{sub NS}R{sub NS}{sup 3}/(P{sub 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.

  11. When Black Holes Collide

    NASA Technical Reports Server (NTRS)

    Baker, John

    2010-01-01

    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.

  12. Variations on Black Themes: English, Black Literature.

    ERIC Educational Resources Information Center

    Randolph, Gloria D.

    Variations on Black Themes, an introductory course in the study of black literature, permits students to make cursory examination of representative works of many black writers for the purpose of identifying major writers and recurring themes. The course content includes: introduction to some works of major Black American authors; identification of…

  13. Black Holes and Firewalls

    NASA Astrophysics Data System (ADS)

    Polchinski, Joseph

    2015-04-01

    Our modern understanding of space, time, matter, and even reality itself arose from the three great revolutions of the early twentieth century: special relativity, general relativity, and quantum mechanics. But a century later, this work is unfinished. Many deep connections have been discovered, but the full form of a unified theory incorporating all three principles is not known. Thought experiments and paradoxes have often played a key role in figuring out how to fit theories together. For the unification of general relativity and quantum mechanics, black holes have been an important arena. I will talk about the quantum mechanics of black holes, the information paradox, and the latest version of this paradox, the firewall. The firewall points to a conflict between our current theories of spacetime and of quantum mechanics. It may lead to a new understanding of how these are connected, perhaps based on quantum entanglement.

  14. Seasonal changes in the expression of energy metabolism-related genes in white adipose tissue and skeletal muscle in female Japanese black bears.

    PubMed

    Shimozuru, Michito; Nagashima, Akiko; Tanaka, Jun; Tsubota, Toshio

    2016-01-01

    Bears undergo annual cycles in body mass: rapid fattening in autumn (i.e., hyperphagia), and mass loss in winter (i.e., hibernation). To investigate how Japanese black bears (Ursus thibetanus japonicus) adapt to such extreme physiological conditions, we analyzed changes in the mRNA expression of energy metabolism-related genes in white adipose tissues and skeletal muscle throughout three physiological stages: normal activity (June), hyperphagia (November), and hibernation (March). During hyperphagia, quantitative real-time polymerase chain reaction analysis revealed the upregulation of de novo lipogenesis-related genes (e.g., fatty acid synthase and diacylglycerol O-acyltransferase 2) in white adipose tissue, although the bears had been maintained with a constant amount of food. In contrast, during the hibernation period, we observed a downregulation of genes involved in glycolysis (e.g., glucose transporter 4) and lipogenesis (e.g., acetyl-CoA carboxylase 1) and an upregulation of genes in fatty acid catabolism (e.g., carnitine palmitoyltransferase 1A) in both tissue types. In white adipose tissues, we observed upregulation of genes involved in glyceroneogenesis, including pyruvate carboxylase and phosphoenolpyruvate carboxykinase 1, suggesting that white adipose tissue plays a role in the recycling of circulating free fatty acids via re-esterification. In addition, the downregulation of genes involved in amino acid catabolism (e.g., alanine aminotransferase) and the TCA cycle (e.g., pyruvate carboxylase) indicated a role of skeletal muscle in muscle protein sparing and pyruvate recycling via the Cori cycle. These examples of coordinated transcriptional regulation would contribute to rapid mass gain during the pre-hibernation period and to energy preservation and efficient energy production during the hibernation period.

  15. Black Holes, Thermodynamics, and Quantum Theory

    NASA Astrophysics Data System (ADS)

    Wald, Robert

    2017-01-01

    A black hole is a region of ``no escape'' that remains behind after a body has undergone complete gravitational collapse. It is truly remarkable that (i) black holes obey the ordinary laws of thermodynamics, (ii) the entropy of a black hole is given by a simple formula involving geometrical properties of its event horizon, and (iii) quantum theory plays an essential role in the thermodynamic properties of black holes. In this talk, I will review some of the key developments related to these properties of black holes, which fascinated me as a graduate student and continue to fascinate me now.

  16. Formation of Supermassive Black Holes in Galactic Bulges: A Rotating Collapse Model Consistent with the M(sub BH-sigma) Relation

    NASA Technical Reports Server (NTRS)

    Adams, Fred C.; Graff, David S.; Mbonye, Manasse; Richstone, Douglas O.

    2003-01-01

    Motivated by the observed correlation between black hole masses M(sub BH) and the velocity dispersion sigma of host galaxies, we develop a theoretical model of black hole formation in galactic bulges (this paper generalizes an earlier ApJ Letter). The model assumes an initial state specified by a uniform rotation rate OMEGA and a density distribution of the form rho = a(sup 2)(sub eff)per2piGR(sup 2)(so that a(sub eff)is an effective transport speed). The black hole mass is determined when the centrifugal radius of the collapse flow exceeds the capture radius of the central black hole (for Schwarzschild geometry). This model reproduces the observed correlation between the estimated black hole masses and the velocity dispersions of galactic bulges, i.e., M(sub BH) approximately equal to 10(sup 8) solar mass(sigma per 200 kilometers per second)(sup 4) where sigma = the square root of 2a(sub eff). To obtain this normalization, the rotation rate OMEGA approximately equal to 2 x 10(exp -15) rad per second. The model also defines a bulge mass scale M(sub B). If we identify the scale M(sub B) with the bulge mass, the model determines the ratio mu(sub B) of black hole mass to the host mass: mu(sub B) approximately equal to 0.0024(sigma per 200 kilometer per second), again in reasonable agreement with observed values. In this scenario, supermassive black holes form quickly (in approximately 10(exp 5) yr) and are born rapidly rotating (with a per M approximately 0.9). This paper also shown how these results depend on the assumed initial conditions; the most important quantity is the initial distribution of specific angular momentum in the precollapse state.

  17. Quantum mechanics of black holes.

    PubMed

    Witten, Edward

    2012-08-03

    The popular conception of black holes reflects the behavior of the massive black holes found by astronomers and described by classical general relativity. These objects swallow up whatever comes near and emit nothing. Physicists who have tried to understand the behavior of black holes from a quantum mechanical point of view, however, have arrived at quite a different picture. The difference is analogous to the difference between thermodynamics and statistical mechanics. The thermodynamic description is a good approximation for a macroscopic system, but statistical mechanics describes what one will see if one looks more closely.

  18. Gasification of black liquor

    DOEpatents

    Kohl, Arthur L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

  19. Gasification of black liquor

    DOEpatents

    Kohl, A.L.

    1987-07-28

    A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediately above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone. 2 figs.

  20. Smoking Cessation among Blacks.

    ERIC Educational Resources Information Center

    Stotts, R. Craig; And Others

    1991-01-01

    Lung cancer is a serious health problem among blacks, with a mortality rate of 119 per 100,000 black males, compared to 81 per 100,000 for white males. Smoking cessation efforts are most successful when tailored to the black community, using black community networks and broadcast media for black audiences. (SLD)

  1. Contemporary Black Theatre.

    ERIC Educational Resources Information Center

    Thomas, Pearl

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

  2. Modelling the cosmological co-evolution of supermassive black holes and galaxies - I. BH scaling relations and the AGN luminosity function

    NASA Astrophysics Data System (ADS)

    Marulli, Federico; Bonoli, Silvia; Branchini, Enzo; Moscardini, Lauro; Springel, Volker

    2008-04-01

    We model the cosmological co-evolution of galaxies and their central supermassive black holes (BHs) within a semi-analytical framework developed on the outputs of the Millennium Simulation. This model, described in detail by Croton et al. and De Lucia and Blaizot, introduces a `radio mode' feedback from active galactic nuclei (AGN) at the centre of X-ray emitting atmospheres in galaxy groups and clusters. Thanks to this mechanism, the model can simultaneously explain: (i) the low observed mass dropout rate in cooling flows; (ii) the exponential cut-off in the bright end of the galaxy luminosity function and (iii) the bulge-dominated morphologies and old stellar ages of the most massive galaxies in clusters. This paper is the first of a series in which we investigate how well this model can also reproduce the physical properties of BHs and AGN. Here we analyse the scaling relations, the fundamental plane and the mass function of BHs, and compare them with the most recent observational data. Moreover, we extend the semi-analytic model to follow the evolution of the BH mass accretion and its conversion into radiation, and compare the derived AGN bolometric luminosity function with the observed one. While we find for the most part a very good agreement between predicted and observed BH properties, the semi-analytic model underestimates the number density of luminous AGN at high redshifts, independently of the adopted Eddington factor and accretion efficiency. However, an agreement with the observations is possible within the framework of our model, provided it is assumed that the cold gas fraction accreted by BHs at high redshifts is larger than at low redshifts.

  3. Relations between and among contaminant concentrations and biomarkers in black bass (Micropterus spp.) and common carp (Cyprinus carpio) from large U.S. rivers, 1995-2004

    USGS Publications Warehouse

    Hinck, J.E.; Schmitt, C.J.; Ellersieck, Mark R.; Tillitt, D.E.

    2008-01-01

    Environmental contaminant and biomarker monitoring data from major U.S. river basins were summarized for black bass (Micropterus spp.) and common carp (Cyprinus carpio) sampled over a nine year period. Cumulative frequency distributions revealed taxon differences for many organochlorine residue concentrations, elemental contaminant concentrations, and biomarkers, but few gender differences were evident for chemical concentrations. Concentrations of dacthal, pentachloroanisole, p,p???-DDE, endosulfan sulfate, barium, cadmium, copper, manganese, lead, selenium, vanadium, and zinc were greater in carp than bass, but concentrations of mercury and magnesium were greater in bass. Gender differences were evident in bass for mercury and in carp for zinc, but the differences were small compared to taxon differences. Greater vitellogenin concentrations, 17??-estradiol concentrations, 17??-estradiol/11-ketotestosterone ratios, and percent oocyte atresia in female carp compared to female bass may be related to the sequential spawning of carp. Regression analyses indicated that as much as 78% of biomarker variation was explained by chemical contaminant concentrations. Sites grouped consistently by river basin in the chemical contaminant principal components analysis (PCA) models and were driven by mercury, magnesium, barium, mirex, and oxychlordane. PCA models for the biomarkers did not group the sites by basin for either bass or carp. Statistical analyses and data interpretation were limited by the study design. The implications of these limitations are discussed. Recommendations to be considered during the planning of future monitoring studies include the exclusion of gender- and species-specific sampling for certain chemical contaminants considering analytical methods with appropriate sensitivities; and allowing for the addition of new chemical and biological variables as methods and information needs evolve. ?? The Royal Society of Chemistry.

  4. Relations between and among contaminant concentrations and biomarkers in black bass (Micropterus spp.) and common carp (Cyprinus carpio) from large U.S. rivers, 1995-2004.

    PubMed

    Hinck, Jo Ellen; Schmitt, Christopher J; Ellersieck, Mark R; Tillitt, Donald E

    2008-12-01

    Environmental contaminant and biomarker monitoring data from major U.S. river basins were summarized for black bass (Micropterus spp.) and common carp (Cyprinus carpio) sampled over a nine year period. Cumulative frequency distributions revealed taxon differences for many organochlorine residue concentrations, elemental contaminant concentrations, and biomarkers, but few gender differences were evident for chemical concentrations. Concentrations of dacthal, pentachloroanisole, p,p'-DDE, endosulfan sulfate, barium, cadmium, copper, manganese, lead, selenium, vanadium, and zinc were greater in carp than bass, but concentrations of mercury and magnesium were greater in bass. Gender differences were evident in bass for mercury and in carp for zinc, but the differences were small compared to taxon differences. Greater vitellogenin concentrations, 17beta-estradiol concentrations, 17beta-estradiol/11-ketotestosterone ratios, and percent oocyte atresia in female carp compared to female bass may be related to the sequential spawning of carp. Regression analyses indicated that as much as 78% of biomarker variation was explained by chemical contaminant concentrations. Sites grouped consistently by river basin in the chemical contaminant principal components analysis (PCA) models and were driven by mercury, magnesium, barium, mirex, and oxychlordane. PCA models for the biomarkers did not group the sites by basin for either bass or carp. Statistical analyses and data interpretation were limited by the study design. The implications of these limitations are discussed. Recommendations to be considered during the planning of future monitoring studies include the exclusion of gender- and species-specific sampling for certain chemical contaminants considering analytical methods with appropriate sensitivities; and allowing for the addition of new chemical and biological variables as methods and information needs evolve.

  5. Consumption of coffee, green tea, oolong tea, black tea, chocolate snacks and the caffeine content in relation to risk of diabetes in Japanese men and women.

    PubMed

    Oba, Shino; Nagata, Chisato; Nakamura, Kozue; Fujii, Kaori; Kawachi, Toshiaki; Takatsuka, Naoyoshi; Shimizu, Hiroyuki

    2010-02-01

    Although the inverse association between coffee consumption and risk of diabetes has been reported numerous times, the role of caffeine intake in this association has remained unclear. We evaluated the consumption of coffee and other beverages and food containing caffeine in relation to the incidence of diabetes. The study participants were 5897 men and 7643 women in a community-based cohort in Takayama, Japan. Consumption of coffee, green tea, oolong tea, black tea and chocolate snacks were measured with a semi-quantitative FFQ in 1992. At the follow-up survey in 2002, the development of diabetes and the time of diagnosis were reported. To assess the association, age, smoking status, BMI, physical activity, education in years, alcohol consumption, total energy intake, fat intake and women's menopausal status were adjusted. Among men who consumed one cup per month to six cups per week and among those who consumed one cup per d or more, the associated hazard ratios were 0.69 (95 % CI 0.50, 0.97) and 0.69 (95 % CI 0.49, 0.98) compared with those who drank little to no coffee, with a P value for trend of 0.32. The hazard ratios for women with the same coffee consumption patterns were 1.08 (95 % CI 0.74, 1.60) and 0.70 (95 % CI 0.44, 1.12), with a P value for trend of 0.03. The association between estimated total caffeine intake and risk of diabetes was insignificant both among men and among women. The results imply that coffee consumption decreased the risk of developing diabetes. The protective effect may exist aside from the influence of caffeine intake.

  6. The Black Hole Experiment Gallery

    NASA Astrophysics Data System (ADS)

    Gould, R.; Dussault, M.; Griswold, A.; Reinfeld, E.; Steel, S.

    2008-06-01

    We report preliminary findings from the development and prototyping of the Black Hole Experiment Gallery, a NASA and NSF-funded national traveling exhibition and related educational materials on black holes. Among the innovations described are partnerships with community-based programs that enable culturally diverse youth to collaborate in exhibit development; and computer-networked technology that helps personalize visitors' exhibit experiences through the creation of a ``digital diary,'' that extends learning beyond the gallery, and that collects embedded evaluation data.

  7. Black Sea

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Black Sea in eastern Russia is experiencing an ongoing phytoplankton bloom. This image, the most recent in a series that began in early may, shows the waters to be even more colorful than before. part of the increased brightness may be due to the presence of sun glint , especially in the center of the sea. However, more organisms appear to be present as well, their photosynthetic pigments reflecting different wavelengths of light.This Moderate Resolution Imaging Spectroradiometer (MODIS) image was captured on June 15, 2002.

  8. Rotating black holes in dilatonic Einstein-Gauss-Bonnet theory.

    PubMed

    Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen

    2011-04-15

    We construct generalizations of the Kerr black holes by including higher-curvature corrections in the form of the Gauss-Bonnet density coupled to the dilaton. We show that the domain of existence of these Einstein-Gauss-Bonnet-dilaton (EGBD) black holes is bounded by the Kerr black holes, the critical EGBD black holes, and the singular extremal EGBD solutions. The angular momentum of the EGBD black holes can exceed the Kerr bound. The EGBD black holes satisfy a generalized Smarr relation. We also compare their innermost stable circular orbits with those of the Kerr black holes and show the existence of differences which might be observable in astrophysical systems.

  9. Strong gravitational lensing by Kiselev black hole

    NASA Astrophysics Data System (ADS)

    Younas, Azka; Jamil, Mubasher; Bahamonde, Sebastian; Hussain, Saqib

    2015-10-01

    We investigate the gravitational lensing scenario due to Schwarzschild-like black hole surrounded by quintessence (Kiselev black hole). We work for the special case of Kiselev black hole where we take the state parameter wq=-2/3 . For the detailed derivation and analysis of the bending angle involved in the deflection of light, we discuss three special cases of Kiselev black hole: nonextreme, extreme, and naked singularity. We also calculate the approximate bending angle and compare it with the exact bending angle. We found the relation of bending angles in the decreasing order as: naked singularity, extreme Kiselev black hole, nonextreme Kiselev black hole, and Schwarzschild black hole. In the weak field approximation, we compute the position and total magnification of relativistic images as well.

  10. More Hidden Black Hole Dangers

    NASA Technical Reports Server (NTRS)

    Wanjek, Christopher

    2003-01-01

    Black holes such as GRO J1655-40 form from collapsed stars. When stars at least eight times more massive than our Sun exhaust their fuel supply, they no longer have the energy to support their tremendous bulk. These stars explode as supernovae, blasting their outer envelopes into space. If the core is more than three times the mass of the Sun, it will collapse into a singularity, a single point of infinite density.Although light cannot escape black holes, astronomers can see black holes by virtue of the hot, glowing gas often stolen from a neighboring star that orbits these objects. From our vantage point, the light seems to flicker. The Rossi Explorer has recorded this flickering (called quasiperiodic oscillations, or QPOs) around many black holes. QPOs are produced by gas very near the innermost stable orbit the closest orbit a blob of gas can maintain before falling pell-mell into the black hole. As gas whips around the black hole at near light speed, gravity pulls the gas in one direction, then another, adding to the flickering. The QPO is related to the speed and size of this orbit and the mass of the black hole.

  11. Magnetic fields around black holes

    NASA Astrophysics Data System (ADS)

    Garofalo, David A. G.

    Active Galactic Nuclei are the most powerful long-lived objects in the universe. They are thought to harbor supermassive black holes that range from 1 million solar masses to 1000 times that value and possibly greater. Theory and observation are converging on a model for these objects that involves the conversion of gravitational potential energy of accreting gas to radiation as well as Poynting flux produced by the interaction of the rotating spacetime and the electromagnetic fields originating in the ionized accretion flow. The presence of black holes in astrophysics is taking center stage, with the output from AGN in various forms such as winds and jets influencing the formation and evolution of the host galaxy. This dissertation addresses some of the basic unanswered questions that plague our current understanding of how rotating black holes interact with their surrounding magnetized accretion disks to produce the enormous observed energy. Two magnetic configurations are examined. The first involves magnetic fields connecting the black hole with the inner accretion disk and the other involves large scale magnetic fields threading the disk and the hole. We study the effects of the former type by establishing the consequences that magnetic torques between the black hole and the inner accretion disk have on the energy dissipation profile. We attempt a plausible explanation to the observed "Deep Minimum" state in the Seyfert galaxy MCG-6- 30-15. For the latter type of magnetic geometry, we study the effects of the strength of the magnetic field threading the black hole within the context of the cherished Blandford & Znajek mechanism for black hole spin energy extraction. We begin by addressing the problem in the non-relativistic regime where we find that the black hole-threading magnetic field is stronger for greater disk thickness, larger magnetic Prandtl number, and for a larger accretion disk. We then study the problem in full relativity where we show that our

  12. Black widow spider

    MedlinePlus

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

  13. Larval distribution and behavior of Chrysomya rufifacies (Macquart) (Diptera:Calliphoridae) relative to other species on Florida black bear(Carnivora:Ursidae) carcasses decompsing in North Central Florida.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Larval interactions of blow flies were documented daily temporally and spatially on 5 black bear carcasses from June – November, 2002. Cochliomyia macellaria or Chrysomya megacephala larvae were collected first, then Chrysomya rufifacies oviposited in multiple locations on the carcasses uninhabited...

  14. Performance of the Black Head Start Children on the Vane Kindergarten Test and the Stanford-Binet as Related to Age and Sex Variables

    ERIC Educational Resources Information Center

    Dube, Gary G.; Rudolph, Jeffrey A.

    1978-01-01

    Assesses the concurrent validity of the Vane Kindergarten Test with low socioeconomic status black preschool children with the Stanford-Binet as the external criterion. Also examines its feasibility with children below the age of 4 1/2. (Author/RK)

  15. U.S. Professional Association Initiatives Related to Black South Africans: An Analysis and An Inventory. Information Exchange: Working Paper #2.

    ERIC Educational Resources Information Center

    Gottlieb, Julie D.

    The nature and level of activity among U.S. private sector groups seeking to expand educational opportunities for black South Africans is examined. The Information Exchange of the Institute of International Education (South African Programs) did research on such categories of organizations as foundations, church groups, educational institutions,…

  16. Why Black-on-Black Homicide?

    ERIC Educational Resources Information Center

    Jeff, Morris F. X., Jr.

    1981-01-01

    The causes of homicides committed against Blacks by Blacks are examined. Major preventive measures are said to be equal opportunity, better jobs, reduction of racial discrimination, elimination of organized crime, removal of drugs from community, and better schools. (JCD)

  17. Black hole collapse and democratic models

    NASA Astrophysics Data System (ADS)

    Jansen, Aron; Magán, Javier M.

    2016-11-01

    We study the evolution of black hole entropy and temperature in collapse scenarios in asymptotically anti-de Sitter spacetime, finding three generic lessons. First, entropy evolution is extensive. Second, at large times, entropy and temperature ring with twice the frequency of the lowest quasinormal mode. Third, the entropy oscillations saturate black hole area theorems in general relativity. The first two features are characteristic of entanglement dynamics in "democratic" models. Solely based on general relativity and the Bekenstein-Hawking entropy formula, our results point to democratic models as microscopic theories of black holes. The third feature can be taken as a prediction for microscopic models of black hole physics.

  18. Dependence of Aerosol Light Absorption and Single-Scattering Albedo On Ambient Relative Humidity for Sulfate Aerosols with Black Carbon Cores

    NASA Technical Reports Server (NTRS)

    Redemann, Jens; Russell, Philip B.; Hamill, Patrick

    2001-01-01

    Atmospheric aerosols frequently contain hygroscopic sulfate species and black carbon (soot) inclusions. In this paper we report results of a modeling study to determine the change in aerosol absorption due to increases in ambient relative humidity (RH), for three common sulfate species, assuming that the soot mass fraction is present as a single concentric core within each particle. Because of the lack of detailed knowledge about various input parameters to models describing internally mixed aerosol particle optics, we focus on results that were aimed at determining the maximum effect that particle humidification may have on aerosol light absorption. In the wavelength range from 450 to 750 nm, maximum absorption humidification factors (ratio of wet to 'dry=30% RH' absorption) for single aerosol particles are found to be as large as 1.75 when the RH changes from 30 to 99.5%. Upon lesser humidification from 30 to 80% RH, absorption humidification for single particles is only as much as 1.2, even for the most favorable combination of initial ('dry') soot mass fraction and particle size. Integrated over monomodal lognormal particle size distributions, maximum absorption humidification factors range between 1.07 and 1.15 for humidification from 30 to 80% and between 1.1 and 1.35 for humidification from 30 to 95% RH for all species considered. The largest humidification factors at a wavelength of 450 nm are obtained for 'dry' particle size distributions that peak at a radius of 0.05 microns, while the absorption humidification factors at 700 nm are largest for 'dry' size distributions that are dominated by particles in the radius range of 0.06 to 0.08 microns. Single-scattering albedo estimates at ambient conditions are often based on absorption measurements at low RH (approx. 30%) and the assumption that aerosol absorption does not change upon humidification (i.e., absorption humidification equal to unity). Our modeling study suggests that this assumption alone can

  19. Black holes in the milky way galaxy.

    PubMed

    Filippenko, A V

    1999-08-31

    Extremely strong observational evidence has recently been found for the presence of black holes orbiting a few relatively normal stars in our Milky Way Galaxy and also at the centers of some galaxies. The former generally have masses of 4-16 times the mass of the sun, whereas the latter are "supermassive black holes" with millions to billions of solar masses. The evidence for a supermassive black hole in the center of our galaxy is especially strong.

  20. Black holes in the Milky Way Galaxy

    PubMed Central

    Filippenko, Alexei V.

    1999-01-01

    Extremely strong observational evidence has recently been found for the presence of black holes orbiting a few relatively normal stars in our Milky Way Galaxy and also at the centers of some galaxies. The former generally have masses of 4–16 times the mass of the sun, whereas the latter are “supermassive black holes” with millions to billions of solar masses. The evidence for a supermassive black hole in the center of our galaxy is especially strong. PMID:10468548

  1. Surface currents and their relations with the satellite-derived temperature for the Black Sea large- and meso-scale circulation features

    SciTech Connect

    Ilyin, Y.P.; Lemeshko, E.M.; Sur, H.I.

    1997-06-01

    In spring-time of 1993,94 both CTD, ADCP and satellite infrared measurements were carried out in the framework of CoMSBlack international program. The ADCP current vectors and thermal structures at the sea surface displayed very good agreement. The velocity maxima coincide with the temperature gradient locations of the Black Sea Rim Current and the vector directions correspond to satellite derived flow configuration. Satellite data assist essentially in the interpretation of ADCP currents data and explain the several peculiarities in vectors distribution as the manifestations of meso-scale dynamic features. The reformation of temperature field took place and it was seen from the satellite observations. These changes are also reflected in current fields peculiarities in spring and summer seasons. The results reflect the effect of the Black Sea flow field transformation from winter type to summer one.

  2. The Flight of Blacks from Central-City Public Schools.

    ERIC Educational Resources Information Center

    Katzman, Martin T.

    1983-01-01

    Discusses the suburbanization of the Black population and declining Black public school enrollment in big cities. Examines the causes and consequences of this trend and its relation, if any, to White flight. (CMG)

  3. Perspectives: Black Holes

    NASA Technical Reports Server (NTRS)

    Dolan, Joseph F.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    When asked to discuss Cyg XR-1, E. E. Salpeter once concluded, 'A black hole in Cyg X(R)-1 is the most conservative hypothesis.' Recent observations now make it likely that a black hole in Cyg XR-1 is the only hypothesis tenable. Chandrasekhar first showed that compact stars - those with the inward force of gravity on their outer layers balanced by the pressure generated by the Pauli exclusion principle acting on its electrons (in white dwarfs) or nucleons (in neutron stars) - have a maximum mass. Equilibrium is achieved at a minimum of the total energy of the star, which is the sum of the positive Fermi energy and the negative gravitational energy. The maximum mass attainable in equilibrium is found by setting E = 0: M(max) = 1.5 M(Sun). If the mass of the star is larger than this, then E can be decreased without bound by decreasing the star's radius and increasing its (negative) gravitational energy. No equilibrium value of the radius exist, and general relativity predicts that gravitational collapse to a point occurs. This point singularity is a black hole.

  4. The Black Hole Universe Model

    NASA Astrophysics Data System (ADS)

    Zhang, Tianxi

    2014-06-01

    The black hole universe model is a multiverse model of cosmology recently developed by the speaker. According to this new model, our universe is a fully grown extremely supermassive black hole, which originated from a hot star-like black hole with several solar masses, and gradually grew up from a supermassive black hole with million to billion solar masses to the present state with trillion-trillion solar masses by accreting ambient matter or merging with other black holes. The entire space is structured with infinite layers or universes hierarchically. The innermost three layers include the universe that we live, the inside star-like and supermassive black holes called child universes, and the outside space called mother universe. The outermost layer is infinite in mass, radius, and entropy without an edge and limits to zero for both the matter density and absolute temperature. All layers are governed by the same physics and tend to expand physically in one direction (outward or the direction of increasing entropy). The expansion of a black hole universe decreases its density and temperature but does not alter the laws of physics. The black hole universe evolves iteratively and endlessly without a beginning. When one universe expands out, a new similar one is formed from inside star-like and supermassive black holes. In each of iterations, elements are resynthesized, matter is reconfigurated, and the universe is renewed rather than a simple repeat. The black hole universe is consistent with the Mach principle, observations, and Einsteinian general relativity. It has only one postulate but is able to explain all phenomena occurred in the universe with well-developed physics. The black hole universe does not need dark energy for acceleration and an inflation epoch for flatness, and thus has a devastating impact on the big bang model. In this talk, I will present how this new cosmological model explains the various aspects of the universe, including the origin

  5. Erratic Black Hole Regulates Itself

    NASA Astrophysics Data System (ADS)

    2009-03-01

    't entirely understand, the other one gets the upper hand." GRS 1915+105 Chandra X-ray Image of GRS 1915+105 The latest Chandra results also show that the wind and the jet carry about the same amount of matter away from the black hole. This is evidence that the black hole is somehow regulating its accretion rate, which may be related to the toggling between mass expulsion via either a jet or a wind from the accretion disk. Self-regulation is a common topic when discussing supermassive black holes, but this is the first clear evidence for it in stellar-mass black holes. "It is exciting that we may be on the track of explaining two mysteries at the same time: how black hole jets can be shut down and also how black holes regulate their growth," said co-author Julia Lee, assistant professor in the Astronomy department at the Harvard-Smithsonian Center for Astrophysics. "Maybe black holes can regulate themselves better than the financial markets!" Although micro-quasars and quasars differ in mass by factors of millions, they should show a similarity in behavior when their very different physical scales are taken into account. People Who Read This Also Read... Chandra Data Reveal Rapidly Whirling Black Holes Jet Power and Black Hole Assortment Revealed in New Chandra Image Celebrate the International Year of Astronomy Ghost Remains After Black Hole Eruption "If quasars and micro-quasars behave very differently, then we have a big problem to figure out why, because gravity treats them the same," said Neilsen. "So, our result is actually very reassuring, because it's one more link between these different types of black holes." The timescale for changes in behavior of a black hole should vary in proportion to the mass. For example, an hour-long timescale for changes in GRS 1915 would correspond to about 10,000 years for a supermassive black hole that weighs a billion times the mass of the Sun. "We cannot hope to explore at this level of detail in any single supermassive black hole

  6. Rotating black holes and Coriolis effect

    NASA Astrophysics Data System (ADS)

    Chou, Chia-Jui; Wu, Xiaoning; Yang, Yi; Yuan, Pei-Hung

    2016-10-01

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the suitable boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  7. Binary black hole merger dynamics and waveforms

    NASA Technical Reports Server (NTRS)

    Baker, John G.; Centrella, Joan; Choi, Dae-II; Koppitz, Michael; vanMeter, James

    2006-01-01

    We apply recently developed techniques for simulations of moving black holes to study dynamics and radiation generation in the last few orbits and merger of a binary black hole system. Our analysis produces a consistent picture from the gravitational wave forms and dynamical black hole trajectories for a set of simulations with black holes beginning on circular-orbit trajectories at a variety of initial separations. We find profound agreement at the level of 1% among the simulations for the last orbit, merger and ringdown, resulting in a final black hole with spin parameter a/m = 0.69. Consequently, we are confident that this part of our waveform result accurately represents the predictions from Einstein's General Relativity for the final burst of gravitational radiation resulting from the merger of an astrophysical system of equal-mass non-spinning black holes. We also find good agreement at a level of roughly 10% for the radiation generated in the preceding few orbits.

  8. Black Hole Interior in Quantum Gravity.

    PubMed

    Nomura, Yasunori; Sanches, Fabio; Weinberg, Sean J

    2015-05-22

    We discuss the interior of a black hole in quantum gravity, in which black holes form and evaporate unitarily. The interior spacetime appears in the sense of complementarity because of special features revealed by the microscopic degrees of freedom when viewed from a semiclassical standpoint. The relation between quantum mechanics and the equivalence principle is subtle, but they are still consistent.

  9. NUMMO, A Black Theatre Journal, Summer, 1978.

    ERIC Educational Resources Information Center

    Morrison, Carl F., Jr., Ed.

    The entries in this journal represent the second annual publication of selected material dealing with the topic of black theatre. Articles describe an evening with the Frank Silvera Writers Workshop in Harlem, relate an interview with Vinie Burrows, explore the thinking of black scholars and artists on the elements of the African-American theatre…

  10. Black Women in the Emerging Services Economy.

    ERIC Educational Resources Information Center

    Woody, Bette

    1989-01-01

    Examines the impact of a services economy on the work and income of Black women in relation to current labor theory, employment patterns of Black and White women, and future policy implications. Discusses the growing feminization of poverty as the product of a growing subculture of low-wage work. (JS)

  11. Life Satisfaction Among Black Urban Elderly

    ERIC Educational Resources Information Center

    Jackson, James S.; And Others

    1977-01-01

    Multiple regression analysis of interview data from 102 non-institutionalized retired black men and women in a large urban area revealed a number of factors related to life satisfaction. Results are supportive of previous findings in whites, but questions raised regarding the applicability of prior findings to black aged. (Author)

  12. Family Size and the Black American.

    ERIC Educational Resources Information Center

    Population Bulletin, 1975

    1975-01-01

    In the past, many family planning and population organizations have paid relatively little attention to black fears of birth control coercion and to the writings, speeches, and attitudes that have resulted. Nor have they considered the history and reasons for black sensitivity on the subject of planned family size. This bulletin puts some of these…

  13. Black Males in College: An Endangered Species?

    ERIC Educational Resources Information Center

    Fuhrmann, Barbara S.; And Others

    Because relatively few black males successfully complete college, this study sought to determine how black male freshmen at a predominantly white university differed from other freshmen in their values, aspirations, and assumptions about college life. In the fall of 1989, the ACT Entering Student Survey, plus 30 locally developed questions, was…

  14. The Black Black Woman and the Black Middle Class.

    ERIC Educational Resources Information Center

    Jeffers, Trellie

    1981-01-01

    Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

  15. Upper bound on the radii of black-hole photonspheres

    NASA Astrophysics Data System (ADS)

    Hod, Shahar

    2013-11-01

    One of the most remarkable predictions of the general theory of relativity is the existence of black-hole “photonspheres”, compact null hypersurfaces on which massless particles can orbit the central black hole. We prove that every spherically-symmetric asymptotically flat black-hole spacetime is characterized by a photonsphere whose radius is bounded from above by rγ⩽3M, where M is the total ADM mass of the black-hole spacetime. It is shown that hairy black-hole configurations conform to this upper bound. In particular, the null circular geodesic of the (bald) Schwarzschild black-hole spacetime saturates the bound.

  16. A Dancing Black Hole

    NASA Astrophysics Data System (ADS)

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

    2002-04-01

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

  17. Can It Really Be This Black and White? An Analysis of the Relative Importance of Ethnic Group and Other Sociodemographic Factors to Patterns of Drug Use and Related Risk among Young Londoners

    ERIC Educational Resources Information Center

    McCambridge, Jim; Strang, John

    2005-01-01

    Two hundred regular users of illegal drugs, aged 16-20, were recruited by peers in ten further education colleges across inner London. Data collected by self-completion questionnaire are presented on patterns of cigarette, alcohol, cannabis, stimulant and other drug use among White, Black and Asian ethnic groups. Multiple and logistic regression…

  18. Periodic X-ray Modulation and its Possible Relation with Eccentricity in Black Hole Binaries : Long-Term Swift/BAT and RXTE/ASM Data Analysis

    NASA Astrophysics Data System (ADS)

    Ghosh, Arindam; Chakrabarti, Sandip Kumar

    2016-07-01

    X-ray binary orbits are expected to have some eccentricity, albeit small. Stellar companion of a black hole orbiting in an eccentric orbit will experience modulating tidal force with a periodicity same as that of the orbital period which will result in a modulation of accretion rates, seed photon flux, and flux of inverse Comptonized harder X-rays as well. Timing analysis of long-term X-ray data (1.5-12 keV) of RXTE/ASM and all sky survey data (15-50 keV) of Swift/BAT satellites reveal this periodicity in several black hole candidates. If this modulation is assumed to be solely due to tidal effects (without taking other effects, such as eclipses, reflection from winds, super-hump phenomena etc. into account), the RMS-value of the peak in power density spectrum allows us to estimate eccentricities of these orbits. We present these very interesting results. We show that our results generally agree with independent studies of these parameters.

  19. A Particle Probing Thermodynamics in Rotating AdS Black Hole

    NASA Astrophysics Data System (ADS)

    Gwak, Bogeun; Lee, Bum-Hoon

    2016-07-01

    We briefly review the thermodynamics of a probe particle absorption to a black hole in this proceeding. The particle energy has a relation to its momenta at the horizon of the black hole. Following this relation, the particle infinitesimally changes the black hole mass and momenta. Under these changes, the changes of properties of the black hole are consistent with the laws of thermodynamics.

  20. Black Holes and the Information Paradox

    NASA Astrophysics Data System (ADS)

    't Hooft, Gerard

    In electromagnetism, like charges repel, opposite charges attract. A remarkable feature of the gravitational force is that like masses attract. This gives rise to an instability: the more mass you have, the stronger the attractive force, until an inevitable implosion follows, leading to a "black hole". It is in the black hole where an apparent conflict between Einstein's General Relativity and the laws of Quantum Mechanics becomes manifest. Most physicists now agree that a black hole should be described by a Schrödinger equation, with a Hermitean Hamiltonian, but this requires a modification of general relativity. Both General Relativity and Quantum mechanics are shaking on their foundations.

  1. Thermodynamic phase transition in the rainbow Schwarzschild black hole

    SciTech Connect

    Gim, Yongwan; Kim, Wontae E-mail: wtkim@sogang.ac.kr

    2014-10-01

    We study the thermodynamic phase transition in the rainbow Schwarzschild black hole where the metric depends on the energy of the test particle. Identifying the black hole temperature with the energy from the modified dispersion relation, we obtain the modified entropy and thermodynamic energy along with the modified local temperature in the cavity to provide well defined black hole states. It is found that apart from the conventional critical temperature related to Hawking-Page phase transition there appears an additional critical temperature which is of relevance to the existence of a locally stable tiny black hole; however, the off-shell free energy tells us that this black hole should eventually tunnel into the stable large black hole. Finally, we discuss the reason why the temperature near the horizon is finite in the rainbow black hole by employing the running gravitational coupling constant, whereas it is divergent near the horizon in the ordinary Schwarzschild black hole.

  2. Formation of black hole and emission of gravitational waves.

    PubMed

    Nakamura, Takashi

    2006-12-01

    Numerical simulations were performed for the formation process of rotating black holes. It is suggested that Kerr black holes are formed for wide ranges of initial parameters. The nature of gravitational waves from a test particle falling into a Kerr black hole as well as the development of 3D numerical relativity for the coalescing binary neutron stars are discussed.

  3. Formation of black hole and emission of gravitational waves

    PubMed Central

    Nakamura, Takashi

    2006-01-01

    Numerical simulations were performed for the formation process of rotating black holes. It is suggested that Kerr black holes are formed for wide ranges of initial parameters. The nature of gravitational waves from a test particle falling into a Kerr black hole as well as the development of 3D numerical relativity for the coalescing binary neutron stars are discussed. PMID:25792793

  4. Much More than Power: The Pedagogy of Promiscuous Black Feminism

    ERIC Educational Resources Information Center

    Huckaby, M. Francyne

    2013-01-01

    This paper explores promiscuous black feminism by juxtaposing black feminism, Foucualt's poststructuralism, and my grandmother. The tensions created by these juxtapositions illuminate the ways black feminism and poststructuralism are resources and challenges to each other, and how both offer understandings of the relations at play that shape…

  5. Black Holes: A Selected Bibliography.

    ERIC Educational Resources Information Center

    Fraknoi, Andrew

    1991-01-01

    Offers a selected bibliography pertaining to black holes with the following categories: introductory books; introductory articles; somewhat more advanced articles; readings about Einstein's general theory of relativity; books on the death of stars; articles on the death of stars; specific articles about Supernova 1987A; relevant science fiction…

  6. Body Image Satisfaction among Blacks

    ERIC Educational Resources Information Center

    Gustat, Jeanette; Carton, Thomas W.; Shahien, Amir A.; Andersen, Lori

    2017-01-01

    Satisfaction with body image is a factor related to health outcomes. The purpose of this study is to examine the relationship between body image satisfaction and body size perception in an urban, Black community sample in New Orleans, Louisiana. Only 42.2% of respondents were satisfied with their body image and 44.1% correctly perceived their body…

  7. NASA's Chandra Finds Black Holes Are "Green"

    NASA Astrophysics Data System (ADS)

    2006-04-01

    Black holes are the most fuel efficient engines in the Universe, according to a new study using NASA's Chandra X-ray Observatory. By making the first direct estimate of how efficient or "green" black holes are, this work gives insight into how black holes generate energy and affect their environment. The new Chandra finding shows that most of the energy released by matter falling toward a supermassive black hole is in the form of high-energy jets traveling at near the speed of light away from the black hole. This is an important step in understanding how such jets can be launched from magnetized disks of gas near the event horizon of a black hole. Illustration of Fuel for a Black Hole Engine Illustration of Fuel for a Black Hole Engine "Just as with cars, it's critical to know the fuel efficiency of black holes," said lead author Steve Allen of the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University, and the Stanford Linear Accelerator Center. "Without this information, we cannot figure out what is going on under the hood, so to speak, or what the engine can do." Allen and his team used Chandra to study nine supermassive black holes at the centers of elliptical galaxies. These black holes are relatively old and generate much less radiation than quasars, rapidly growing supermassive black holes seen in the early Universe. The surprise came when the Chandra results showed that these "quiet" black holes are all producing much more energy in jets of high-energy particles than in visible light or X-rays. These jets create huge bubbles, or cavities, in the hot gas in the galaxies. Animation of Black Hole in Elliptical Galaxy Animation of Black Hole in Elliptical Galaxy The efficiency of the black hole energy-production was calculated in two steps: first Chandra images of the inner regions of the galaxies were used to estimate how much fuel is available for the black hole; then Chandra images were used to estimate the power required to produce

  8. Spacetime and orbits of bumpy black holes

    SciTech Connect

    Vigeland, Sarah J.; Hughes, Scott A.

    2010-01-15

    Our Universe contains a great number of extremely compact and massive objects which are generally accepted to be black holes. Precise observations of orbital motion near candidate black holes have the potential to determine if they have the spacetime structure that general relativity demands. As a means of formulating measurements to test the black hole nature of these objects, Collins and Hughes introduced ''bumpy black holes'': objects that are almost, but not quite, general relativity's black holes. The spacetimes of these objects have multipoles that deviate slightly from the black hole solution, reducing to black holes when the deviation is zero. In this paper, we extend this work in two ways. First, we show how to introduce bumps which are smoother and lead to better behaved orbits than those in the original presentation. Second, we show how to make bumpy Kerr black holes--objects which reduce to the Kerr solution when the deviation goes to zero. This greatly extends the astrophysical applicability of bumpy black holes. Using Hamilton-Jacobi techniques, we show how a spacetime's bumps are imprinted on orbital frequencies, and thus can be determined by measurements which coherently track the orbital phase of a small orbiting body. We find that in the weak field, orbits of bumpy black holes are modified exactly as expected from a Newtonian analysis of a body with a prescribed multipolar structure, reproducing well-known results from the celestial mechanics literature. The impact of bumps on strong-field orbits is many times greater than would be predicted from a Newtonian analysis, suggesting that this framework will allow observations to set robust limits on the extent to which a spacetime's multipoles deviate from the black hole expectation.

  9. Black lenses in string theory

    NASA Astrophysics Data System (ADS)

    Kunduri, Hari K.; Lucietti, James

    2016-09-01

    We present a new supersymmetric, asymptotically flat, black hole solution to five-dimensional U (1 )3 supergravity which is regular on and outside an event horizon of lens space topology L (2 ,1 ). The solution has seven independent parameters and uplifts to a family of 1 /8 -supersymmetric D1-D5-P black brane solutions to type IIB supergravity. The decoupling limit is asymptotically AdS3×S3×T4 , with a near-horizon geometry that is a twisted product of the near-horizon geometry of the extremal Bañados-Teitelboim-Zanelli black hole and L (2 ,1 )×T4, although it is not (locally) a product space in the bulk. We show that the decoupling limit of a special case of the black lens is related to that of a black ring by spectral flow, thereby supplying an account of its entropy. Analogous solutions of U (1 )N supergravity are also presented.

  10. NASA Now: Black Holes

    NASA Video Gallery

    In this NASA Now episode, Dr. Daniel Patnaude talks about how his team discovered a baby black hole, why this is important and how black holes create tidal forces. Throughout his discussion, Patnau...

  11. Black nightshade poisoning

    MedlinePlus

    ... when someone eats pieces of the black nightshade plant. This article is for information only. DO NOT ... Found Poisons are found in the black nightshade plant, especially in the unripened fruit and leaves. Symptoms ...

  12. Black Soybean Seed Coat Extract Prevents Hydrogen Peroxide-Mediated Cell Death via Extracellular Signal-Related Kinase Signalling in HepG2 Cells.

    PubMed

    Hashimoto, Naoto; Oki, Tomoyuki; Sasaki, Kazunori; Suda, Ikuo; Okuno, Shigenori

    2015-01-01

    Oxidative stress reduces cell viability and contributes to disease processes. Flavonoids including anthocyanins and proanthocyanidins reportedly induce intracellular antioxidant defence systems. Thus, in this study, we examined the antioxidant effects of a commercial extract from black soybean seed coats (BE), which are rich in anthocyanin and proanthocyanidin, and investigated the associated intracellular mechanisms in HepG2 cells. HepG2 cells treated with hydrogen peroxide (HPO) showed 60% viability, whereas pretreatment with BE-containing media for 2 h ameliorated HPO-mediated cell death by up to 90%. Pretreatment with BE for 2 h partially blocked HPO-mediated activation of ERK in HepG2 cells, and that for 1 h led to a 20% increase in intracellular total protein phosphatase (PP) activity, which is known to deactivate protein kinases. These results indicate that BE prevents HPO-mediated cell damage by inhibiting ERK signalling, potentially via PPs.

  13. Separability of the massive Dirac equation in 5-dimensional Myers-Perry black hole geometry and its relation to a rank-three Killing-Yano tensor

    SciTech Connect

    Wu Shuangqing

    2008-09-15

    The Dirac equation for the electron around a five-dimensional rotating black hole with two different angular momenta is separated into purely radial and purely angular equations. The general solution is expressed as a superposition of solutions derived from these two decoupled ordinary differential equations. By separating variables for the massive Klein-Gordon equation in the same spacetime background, I derive a simple and elegant form for the Staeckel-Killing tensor, which can be easily written as the square of a rank-three Killing-Yano tensor. I have also explicitly constructed a symmetry operator that commutes with the scalar Laplacian by using the Staeckel-Killing tensor, and the one with the Dirac operator by the Killing-Yano tensor admitted by the five-dimensional Myers-Perry metric, respectively.

  14. Black and gold howler monkeys (Alouatta caraya) as sentinels of ecosystem health: patterns of zoonotic protozoa infection relative to degree of human-primate contact.

    PubMed

    Kowalewski, Martin M; Salzer, Johanna S; Deutsch, Joseph C; Raño, Mariana; Kuhlenschmidt, Mark S; Gillespie, Thomas R

    2011-01-01

    Exponential expansion of human populations and human activities within primate habitats has resulted in high potential for pathogen exchange creating challenges for biodiversity conservation and global health. Under such conditions, resilient habitat generalists such as black and gold howler monkeys (Alouatta caraya) may act as effective sentinels to overall ecosystem health and alert us to impending epidemics in the human population. To better understand this potential, we examined noninvasively collected fecal samples from black and gold howler monkeys from remote, rural, and village populations in Northern Argentina. We examined all samples (n=90) for the zoonotic protozoa Cryptosporidium sp. and Giardia sp. via immunofluorescent antibody (IFA) detection. All samples were negative for Cryptosporidium sp. The prevalence of Giardia sp. was significantly higher at the rural site (67%) compared with the remote forest (57%) and village (40%) sites. A lack of Cryptosporidium sp. in all samples examined suggests that this pathogen is not a natural component of the howler parasite communities at these sites and that current land-use patterns and livestock contact are not exposing Argentine howler monkeys to this pathogen. High prevalence of Giardia sp. at all sites suggests that howler monkeys may serve as a viable reservoir for Giardia. Significantly higher prevalence of Giardia sp. at the rural site, where primate-livestock contact is highest, suggests the presence of multiple Giardia clades or increased exposure to Giardia through repeated zoonotic transmission among nonhuman primates, livestock, and/or people. These results highlight the need for future research into the epidemiology, cross-species transmission ecology, and clinical consequences of Giardia and other infectious agents not only in humans and livestock, but also in the wild animals that share their environments.

  15. Black Hole Thermodynamics

    NASA Astrophysics Data System (ADS)

    Israel, Werner

    This chapter reviews the conceptual developments on black hole thermodynamics and the attempts to determine the origin of black hole entropy in terms of their horizon area. The brick wall model and an operational approach are discussed. An attempt to understand at the microlevel how the quantum black hole acquires its thermal properties is included. The chapter concludes with some remarks on the extension of these techniques to describing the dynamical process of black hole evaporation.

  16. Accelerating black diholes and static black dirings

    SciTech Connect

    Teo, Edward

    2006-01-15

    We show how a recently discovered black-ring solution with a rotating 2-sphere can be turned into two new solutions of Einstein-Maxwell-dilaton theory. The first is a four-dimensional solution describing a pair of oppositely charged, extremal black holes--known as a black dihole--undergoing uniform acceleration. The second is a five-dimensional solution describing a pair of concentric, static extremal black rings carrying opposite dipole charges--a so-called black diring. The properties of both solutions, which turn out to be formally very similar, are analyzed in detail. We also present, in an appendix, an accelerating version of the Zipoy-Voorhees solution in four-dimensional Einstein gravity.

  17. Black Veterans Return

    ERIC Educational Resources Information Center

    Fendrich, James; Pearson, Michael

    1970-01-01

    This is a survey study of black veterans' attitudes toward white authorities, the "law and order controversy, racial separatism, violence, and black identification. Results of the survey are held to suggest that alienation will move a substantial proportion of these veterans into the black radical movement. (KG)

  18. Black Studies Perspectives

    ERIC Educational Resources Information Center

    Adams, Russell L.

    1977-01-01

    Discusses the proposition that the black studies movement is but a continuing aspect of our general battle for survival and liberation in a fluctuatingly hostile environment, and that a part of what is seen today in the black studies movement is but a fluctuation in a fight and an expression of black collective awareness dating back to the…

  19. The Black Woman.

    ERIC Educational Resources Information Center

    Browne, Juanita M.

    The Black woman has been the transmitter of culture in the black community. Two of the important roles of African women were perpetuated during slavery and continue until today. They are her role in economic endeavor and her close bond with her children. The woman in African society was additionally politically significant. The black woman has…

  20. Asymmetric Black Diholes

    SciTech Connect

    Manko, V. S.; Sanchez-Mondragon, J.; Ruiz, E.

    2009-05-01

    In the present paper we enlarge the list of black dihole spacetimes by introducing the notion of asymmetric black diholes which describe configurations composed of two static charged black holes endowed with unequal masses and equal but opposite charges. The asymmetric dihole solutions are considered both in the Einstein-Maxwell and Einstein-Maxwell-dilaton theories.

  1. Violent flickering in Black Holes

    NASA Astrophysics Data System (ADS)

    2008-10-01

    Unique observations of the flickering light from the surroundings of two black holes provide new insights into the colossal energy that flows at their hearts. By mapping out how well the variations in visible light match those in X-rays on very short timescales, astronomers have shown that magnetic fields must play a crucial role in the way black holes swallow matter. Flickering black hole ESO PR Photo 36/08 Flickering black hole Like the flame from a candle, light coming from the surroundings of a black hole is not constant -- it flares, sputters and sparkles. "The rapid flickering of light from a black hole is most commonly observed at X-ray wavelengths," says Poshak Gandhi, who led the international team that reports these results. "This new study is one of only a handful to date that also explore the fast variations in visible light, and, most importantly how these fluctuations relate to those in X-rays." The observations tracked the shimmering of the black holes simultaneously using two different instruments, one on the ground and one in space. The X-ray data were taken using NASA's Rossi X-ray Timing Explorer satellite. The visible light was collected with the high speed camera ULTRACAM, a visiting instrument at ESO's Very Large Telescope (VLT), recording up to 20 images a second. ULTRACAM was developed by team members Vik Dhillon and Tom Marsh. "These are among the fastest observations of a black hole ever obtained with a large optical telescope," says Dhillon. To their surprise, astronomers discovered that the brightness fluctuations in the visible light were even more rapid than those seen in X-rays. In addition, the visible-light and X-ray variations were found not to be simultaneous, but to follow a repeated and remarkable pattern: just before an X-ray flare the visible light dims, and then surges to a bright flash for a tiny fraction of a second before rapidly decreasing again. None of this radiation emerges directly from the black hole, but from the

  2. Black Hole Battery

    NASA Astrophysics Data System (ADS)

    Levin, Janna; D'Orazio, Daniel

    2016-03-01

    Black holes are dark dead stars. Neutron stars are giant magnets. As the neutron star orbits the black hole, an electronic circuit forms that generates a blast of power just before the black hole absorbs the neutron star whole. The black hole battery conceivably would be observable at cosmological distances. Possible channels for luminosity include synchro-curvature radiation, a blazing fireball, or even an unstable, short-lived black hole pulsar. As suggested by Mingarelli, Levin, and Lazio, some fraction of the battery power could also be reprocessed into coherent radio emission to populate a subclass of fast radio bursts.

  3. No supermassive black hole in M33?

    PubMed

    Merritt, D; Ferrarese, L; Joseph, C L

    2001-08-10

    We observed the nucleus of M33, the third-brightest galaxy in the Local Group, with the Space Telescope Imaging Spectrograph at a resolution at least a factor of 10 higher than previously obtained. Rather than the steep rise expected within the radius of gravitational influence of a supermassive black hole, the random stellar velocities showed a decrease within a parsec of the center of the galaxy. The implied upper limit on the mass of the central black hole is only 3000 solar masses, about three orders of magnitude lower than the dynamically inferred mass of any other supermassive black hole. Detecting black holes of only a few thousand solar masses is observationally challenging, but it is critical to establish how supermassive black holes relate to their host galaxies, and which mechanisms influence the formation and evolution of both.

  4. Cosmic microwave background radiation of black hole universe

    NASA Astrophysics Data System (ADS)

    Zhang, T. X.

    2010-11-01

    Modifying slightly the big bang theory, the author has recently developed a new cosmological model called black hole universe. This new cosmological model is consistent with the Mach principle, Einsteinian general theory of relativity, and observations of the universe. The origin, structure, evolution, and expansion of the black hole universe have been presented in the recent sequence of American Astronomical Society (AAS) meetings and published recently in a scientific journal: Progress in Physics. This paper explains the observed 2.725 K cosmic microwave background radiation of the black hole universe, which grew from a star-like black hole with several solar masses through a supermassive black hole with billions of solar masses to the present universe with hundred billion-trillions of solar masses. According to the black hole universe model, the observed cosmic microwave background radiation can be explained as the black body radiation of the black hole universe, which can be considered as an ideal black body. When a hot and dense star-like black hole accretes its ambient materials and merges with other black holes, it expands and cools down. A governing equation that expresses the possible thermal history of the black hole universe is derived from the Planck law of black body radiation and radiation energy conservation. The result obtained by solving the governing equation indicates that the radiation temperature of the present universe can be ˜2.725 K if the universe originated from a hot star-like black hole, and is therefore consistent with the observation of the cosmic microwave background radiation. A smaller or younger black hole universe usually cools down faster. The characteristics of the original star-like or supermassive black hole are not critical to the physical properties of the black hole universe at present, because matter and radiation are mainly from the outside space, i.e., the mother universe.

  5. IMAGES OF BLACK AMERICANS

    PubMed Central

    Fiske, Susan T.; Bergsieker, Hilary B.; Russell, Ann Marie; Williams, Lyle

    2013-01-01

    Images of Black Americans are becoming remarkably diverse, enabling Barack Obama to defy simple-minded stereotypes and succeed. Understood through the Stereotype Content Model’s demonstrably fundamental trait dimensions of perceived warmth and competence, images of Black Americans show three relevant patterns. Stereotyping by omission allows non-Blacks to accentuate the positive, excluding any lingering negativity but implying it by its absence; specifically, describing Black Americans as gregarious and passionate suggests warmth but ignores competence and implies its lack. Obama’s credentials prevented him from being cast as incompetent, though the experience debate continued. His legendary calm and passionate charisma saved him on the warmth dimension. Social class subtypes for Black Americans differentiate dramatically between low-income Blacks and Black professionals, among both non-Black and Black samples. Obama clearly fit the moderately warm, highly competent Black-professional subtype. Finally, the campaign’s events (and nonevents) allowed voter habituation to overcome non-Blacks’ automatic emotional vigilance to Black Americans. PMID:24235974

  6. The Black Executive: A Challenge for Psychiatry

    PubMed Central

    Boone, Lillian Ruth

    1982-01-01

    The task of developing a body of knowledge about specific problems, both intrapsychic and psychosocial, which influence a black executive's maturation, must be initiated. There is currently a definite interest, among black executives, in obtaining access to appropriate psychotherapeutic intervention. A psychobiographical approach facilitates development of a construct for analysis of, and insight into, transference phenomena that translate into organization based behavioral responses to the black executive. Analysis of frequently encountered organizational ethos and also stimulus-response mechanisms in the black executive lead to formulation of viable conclusions for resolution of conflict. Modes of recognition of specific conflict with authority in the black executive psychotherapy patient include examination of (1) defense mechanisms frequently encountered in response to authority conflicts, (2) stated intentions of the patient in relation to career development, and (3) the affective stance of the patient. Psychobiographical issues very often have a direct developmental influence on black familial conceptualizations of authority. Childrearing practices and parentally based ego ideals and other aspects of development are linked to analogues in adult human behavior frequently observed among black executives. Suggestions for therapeutic directions involve affective and thematic strategies, all contingent upon a productive, informed, therapeutic effort. The therapeutic relationship is a most important element in the treatment strategy with the black executive. PMID:7120460

  7. From navigation to negotiation: an examination of the lived experiences of Black gay male alumni of historically Black colleges and universities.

    PubMed

    Ford, Obie

    2015-01-01

    This research presents an examination of Black gay men and their lived experiences while undergraduates at historically Black colleges and universities (HBCUs). Based on 10 in-depth interviews with self-identified Black gay men, the author presents four emergent themes, which reveal the complex ways in which Black gay men navigate and negotiate the intersections of their multiple identities as related to race, sexual orientation, and gender at HBCUs. The findings of this research have implications for larger discussions of community, Black masculinity, and gay identity in predominantly Black and non-Black contexts.

  8. Larval Distribution and Behavior of Chrysomya rufifacies (Macquart) (Diptera: Calliphoridae) Relative to Other Species on Florida Black Bear (Carnivora: Ursidae) Decomposing Carcasses.

    PubMed

    Swiger, S L; Hogsette, J A; Butler, J F

    2014-02-01

    Larval interactions of dipteran species, blow flies in particular, were observed and documented daily over time and location on five black bear carcasses in Gainesville, FL, USA, from June 2002 - September 2004. Cochliomyia macellaria (Fabricius) or Chrysomya megacephala (Fabricius) larvae were collected first, after which Chrysomya rufifacies (Macquart) oviposited on the carcasses in multiple locations (i.e., neck, anus, and exposed flesh) not inhabited already by the other blow fly larvae. Within the first week of decomposition, C. rufifacies larvae grew to ≥12 mm, filling the carcasses with thousands of larvae and replacing the other calliphorid larvae either through successful food source competition or by predation. As a result, C. macellaria and C. megacephala were not collected past their third instar feeding stage. The blow fly species, C. megacephala, C. macellaria, Lucilia caeruleiviridis (Macquart), Phormia regina (Meigen), Lucilia sericata (Meigen), and C. rufifacies, completed two developmental cycles in the 88.5-kg carcass. This phenomenon might serve to complicate or prevent the calculation of an accurate postmortem interval.

  9. Influence of mining-related activities on concentrations of metals in water and sediment from streams of the Black Hills, South Dakota

    USGS Publications Warehouse

    May, T.W.; Wiedmeyer, Ray H.; Gober, J.; Larson, S.

    2001-01-01

    Water and sediment samples were collected from streams in Spearfish Creek, Whitewood Creek, and Bear Butte Creek watersheds in the Black Hills, SD, an area impacted by gold mining operations. Arsenic concentrations that exceeded the U.S. Environmental Protection Agency's Maximum Concentration Limit of 50 ??g/L for drinking water were found in water from Annie Creek, a tributary of Spearfish Creek, and from Whitewood Creek. Gold Run, a tributary of Whitewood Creek, and Annie Creek contained Se concentrations in water that exceeded the EPA Ecotox threshold of 5 ??g/L and were classified as a high hazard for Se accumulation from water into the planktonic food chain and for resultant toxicity to fish and aquatic birds. Concentrations of As, Cd, Cu, Hg, Ni, Pb, and Zn in sediment exceeded EPA Ecotox thresholds in one or more of the watersheds suggesting potential adverse ecological effects. Sediment from Rubicon Creek, a tributary of Spearfish Creek, contained Se concentrations high enough (4.0 ??g/g) to be a moderate hazard for accumulation from sediments into the benthic food chain, with resultant dietary toxicity to fish and aquatic birds. These results are discussed in light of historical mining activities and recent clean-up and reclamation efforts. Based on the results and comparisons to Ecotox tresholds, further studies of ecological effects are warranted.

  10. Influence of rice whole-crop silage diet on growth performance, carcass and meat characteristics and muscle-related gene expression in Japanese Black steers.

    PubMed

    Shibata, Masahiro; Hikino, Yasuko; Imanari, Mai; Matsumoto, Kazunori; Yamamoto, Naoyuki

    2016-07-01

    The present study investigated the influence of a diet largely comprising rice whole-crop silage (rWCS) on growth performance, carcass and meat characteristics, and expression of genes involved in muscle growth of Japanese Black steers. Steers were randomly separated into rWCS-fed (rWCS ad libitum and restricted feeding of concentrate) and concentrate-fed groups. Total digestible nutrient intake and daily gain (DG) decreased in rWCS-fed steers in comparison with concentrate-fed steers, whereas dressed carcass weight and final body weight did not significantly differ between the groups. Decreases in drip loss in the muscle of rWCS-fed steers may be caused by α-tocopherol and β-carotene in muscle. Feeding large amounts of rWCS to steers may maintain quantitative productivity of beef steers equally to a concentrate-based diet, and improve the qualitative productivity. Results of gene expression suggest that activation of skeletal muscle growth in rWCS-fed steers may occur at the late fattening period owing to a decrease in myostatin and increase in myosin heavy chain gene expression. Preadipocyte factor-1 and myostatin genes may be strongly involved in the control of lipid accumulation. This rearing system would allow beef production to switch to rWCS-based diets from concentrate-based diets.

  11. Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops)

    PubMed Central

    Lotterhos, Katie E; Dick, Stefan J; Haggarty, Dana R

    2014-01-01

    Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes. PMID:24567745

  12. Insects in relation to black locust culture on surface-mine spoil in Kentucky, with emphasis on the locust twig borer, Ecdytolopha insiticiana Zell. (Lepidoptera: Tortricidae)

    SciTech Connect

    Thoeny, W.T.

    1986-01-01

    This research evaluated the impacts of herbivorous insects, emphasizing the locust twig borer, Ecdytolopha insiticiana Zeller, on black locust, Robinia pseudoacacia L., coppice production on a coal surface-mine spoil site in southeastern Kentucky. The natural history of E. insiticiana was also studied. The locust twig borer was a persistent and damaging pest in first-year coppice, which provided suitable larval habitat throughout the growing season. The locust leafminer, Odontota dorsalis (Thunberg), fed minimally on first-year coppice foliage except during 1983, when trees were severely drought-stressed. Soil-applied granular carbofuran significantly reduced infestations. Lindane stem treatments were not effective, but entire-tree applications did reduce herbivory. Stump sprouts with reduced levels of herbivory grew significantly taller than controls at both spacings in 1983, but only at the more dense spacing in 1984. Blacklight trap collections revealed two generations/year, and adults were present from early May until late August. Four species of hymenopterous and two species of dipterous parasitoids were recovered from E. insiticiana larvae.

  13. Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops).

    PubMed

    Lotterhos, Katie E; Dick, Stefan J; Haggarty, Dana R

    2014-02-01

    Marine reserves networks are implemented as a way to mitigate the impact of fishing on marine ecosystems. Theory suggests that a reserve network will function synergistically when connected by dispersal, but the scale of dispersal is often unknown. On the Pacific coast of the United States and Canada, both countries have recently implemented a number of rockfish conservation areas (RCAs) to protect exploited rockfish species, but no study has evaluated the connectivity within networks in each country or between the two countries. We used isolation-by-distance theory to estimate the scale of dispersal from microsatellite data in the black rockfish, Sebastes melanops, and compared this estimate with the distance between RCAs that would protect this species. Within each country, we found that the distance between RCAs was generally within the confidence intervals of mean dispersal per generation. The distance between these two RCA networks, however, was greater than the average dispersal per generation. The data were also consistent with a genetic break between southern Oregon and central Oregon. We discuss whether additional nearshore RCAs in southern Oregon and Washington would help promote connectivity between RCA's for shallow-water rockfishes.

  14. School Composition and the Black-White Achievement Gap. NCES 2015-018

    ERIC Educational Resources Information Center

    Bohrnstedt, G.; Kitmitto, S.; Ogut, B.; Sherman, D.; Chan, D.

    2015-01-01

    School Composition and the Black-White Achievement Gap explores public schools' demographic composition, in particular, the proportion of Black students enrolled in schools (also referred to "Black student density" in schools) and its relation to the Black-White achievement gap. This NCES study, the first of its kind, used the 2011 NAEP…

  15. Critical Race Theory and the Perspectives of Black Men Teachers in the Los Angeles Public Schools.

    ERIC Educational Resources Information Center

    Lynn, Marvin

    2002-01-01

    Used critical race theory to examine black male teachers' perspectives on their racial identity in relation to their connection and responsibility toward students, noting trends in educational research and theory (black teachers as invisible or inconsequential and more nuanced understandings of black teachers' roles in urban schools). Black male…

  16. Intergroup Stereotypes of Working Class Blacks and Whites: Implications for Stereotype Threat.

    ERIC Educational Resources Information Center

    Niemann, Yolanda Flores; O'Connor, Elizabeth; McClorie, Randall

    1998-01-01

    Examined stereotypes of urban blacks and whites at a flea market with 68 black respondents, and at another flea market with 20 white respondents. Cluster-analysis results show that blacks have a relatively complex, multidimensional representation of themselves and of whites, while whites seem to have a more simplistic and negative view of blacks.…

  17. Black Holes (With 16 figures)

    NASA Astrophysics Data System (ADS)

    Novikov, Igor

    Astrophysics of Black Holes Introduction The Origin of Stellar Black Holes A Nonrotating Black Hole Introduction Schwarzschild Gravitational Field Motion of Photons Along the Radial Direction Radial Motion of Nonrelativistic Particles The Puzzle of the Gravitational Radius R and T Regions Two Types of T-Regions Gravitational Collapse and White Holes Eternal Black Hole? Black Hole Celestial Mechanics Circular Motion Around a Black Hole Gravitational Capture of Particles by a Black Hole Corrections for Gravitational Radiation A Rotating Black Hole Introduction Gravitational Field of a Rotating Black Hole Specific Reference Frames General Properties of the Spacetime of a Rotating Black Hole; - Spacetime Inside the Horizon Celestial Mechanics of a Rotating Black Hole Motion of Particle in the Equatorial Plane Motion of Particles off the Equatorial Plane Peculiarities of the Gravitational Capture of Bodies by a Rotating - Black Hole Electromagnetic Fields Near a Black Hole Introduction Maxwell's Equations in the Neighborhood of a Rotating Black Hole Stationary Electrodynamics Boundary Conditions at the Event Horizon Electromagnetic Fields in Vacuum Magnetosphere of a Black Hole Some Aspects of Physics of Black Holes, Wormholes, and Time Machines Observational Appearence of the Black Holes in the Universe Black Holes in the Interstellar Medium Disk Accretion Black Holes in Stellar Binary Systems Black Holes in Galactic Centers Dynamical Evidence for Black Holes in Galaxy Nuclei Primordial Black Holes Acknowledgements References

  18. Developing Reading Potential in Black Remedial High School Freshmen.

    ERIC Educational Resources Information Center

    Knott, Gladys P.

    1979-01-01

    Suggests that knowledge of relational structures in combination with techniques for determining the meaning of unknown lexical terms assists Black disabled readers in improving their reading performance. (FL)

  19. NASA Observatory Confirms Black Hole Limits

    NASA Astrophysics Data System (ADS)

    2005-02-01

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

  20. Surfing a Black Hole

    NASA Astrophysics Data System (ADS)

    2002-10-01

    Ageorges, Chris Lidman, Alan F.M. Moorwood, Jason Spyromilio and Norbert Hubin (ESO) and Karl M. Menten (Max-Planck-Institut für Radioastronomie, Bonn, Germany). [3]: The NACO facility has two major components, CONICA and NAOS . The COudé Near-Infrared CAmera (CONICA) was developed by a German Consortium, with an extensive ESO collaboration. The Consortium consists of Max-Planck-Institut für Astronomie (MPIA) (Heidelberg) and the Max-Planck-Institut für Extraterrestrische Physik (MPE) (Garching). The Nasmyth Adaptive Optics System (NAOS) was developed, with the support of INSU-CNRS, by a French Consortium in collaboration with ESO. The French consortium consists of Office National d'Etudes et de Recherches Aérospatiales (ONERA) , Laboratoire d'Astrophysique de Grenoble (LAOG) and Observatoire de Paris (DESPA and DASGAL). [4]: In Albert Einstein's Theory of General Relativity, any mass has a characteristic radius, the "event horizon", or "Schwarzschild radius" named after the German astrophysicist Karl Schwarzschild . Within this radius, even light cannot escape the pull of the gravitational force. The radius for a 2.6 ± 0.2 million solar masses black hole (as the one at the centre of the Milky Way galaxy) is about 7.7 million km (26 light-seconds). [5]: Astronomical distances are often expressed in the time it takes the light, travelling at 300,000 km/sec, to cover them. 1 light-hour = 1.08 10 9 km; 1 light-day = 2.6 10 10 km; 1 light-month = 7.8 10 11 km; 1 light-year = 9.5 10 12 km. [6]: Earlier NACO images have been published in ESO PR 25/01 , ESO PR Photos 04a-c/02 , ESO PR Photos 19a-c/02 and ESO PR Photos 21a-c/02. [7]: S2 is an otherwise "normal" star, but some 15 times more massive and 7 times larger than the Sun. Its orbit around the Black Hole is comparatively stable. Even though it moves relatively close to the Black Hole in the present orbit, S2 would have to be at least 70 times closer (about 16 light-minutes from the Black Hole) before it would risk

  1. Effect on tumor necrosis factor-α production and antioxidant ability of black alder, as factors related to its anti-inflammatory properties.

    PubMed

    Acero, Nuria; Muñoz-Mingarro, Dolores

    2012-06-01

    Alders exhibit several uses in different areas and also offer some nutritional and medicinal values. The bark and leaves from black alder [Alnus glutinosa (L.) Gaertn] are used in folk medicine for the treatment of inflammatory processes and other health disorders. This study assessed if an extract of A. glutinosa stem bark exhibits some biological properties linked to improving the inflammatory state, which could partly justify its ethnopharmacological use. Therefore, various aspects of antioxidant activity as well as the effect on tumor necrosis factor-α (TNF-α) production were evaluated. The phytochemical study revealed the presence of terpenes, saponins, tannins, flavonoids, and anthraquinones (by high-performance thin-layer chromatography). The betulinic acid content in the extract, determined by reversed-phase high-performance liquid chromatography (validated method), was 0.72±0.027%. In addition, high amounts for total phenols as well as flavonoids were determined. The extract exhibited a 2,2'-diphenylpicrylhydrazyl radical scavenging capacity similar to that of ascorbic acid and had a significant effect on superoxide anion scavenging, superior to that of ascorbic acid. It was also able to protect HeLa cells from induced oxidative stress. In the TNF-α assay, levels of this citokine were depressed by the extract in HL-60 cells. To test the effect of the extract on cell proliferation, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed. According to the results, the antioxidant properties displayed by the extract of A. glutinosa stem bark, together with the effect on TNF-α levels, suggest that these activities, linked to a successful reduction in inflammatory processes, may support, in part, its ethnopharmacological use.

  2. Effect on Tumor Necrosis Factor-α Production and Antioxidant Ability of Black Alder, as Factors Related to Its Anti-Inflammatory Properties

    PubMed Central

    Acero, Nuria

    2012-01-01

    Abstract Alders exhibit several uses in different areas and also offer some nutritional and medicinal values. The bark and leaves from black alder [Alnus glutinosa (L.) Gaertn] are used in folk medicine for the treatment of inflammatory processes and other health disorders. This study assessed if an extract of A. glutinosa stem bark exhibits some biological properties linked to improving the inflammatory state, which could partly justify its ethnopharmacological use. Therefore, various aspects of antioxidant activity as well as the effect on tumor necrosis factor-α (TNF-α) production were evaluated. The phytochemical study revealed the presence of terpenes, saponins, tannins, flavonoids, and anthraquinones (by high-performance thin-layer chromatography). The betulinic acid content in the extract, determined by reversed-phase high-performance liquid chromatography (validated method), was 0.72±0.027%. In addition, high amounts for total phenols as well as flavonoids were determined. The extract exhibited a 2,2′-diphenylpicrylhydrazyl radical scavenging capacity similar to that of ascorbic acid and had a significant effect on superoxide anion scavenging, superior to that of ascorbic acid. It was also able to protect HeLa cells from induced oxidative stress. In the TNF-α assay, levels of this citokine were depressed by the extract in HL-60 cells. To test the effect of the extract on cell proliferation, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed. According to the results, the antioxidant properties displayed by the extract of A. glutinosa stem bark, together with the effect on TNF-α levels, suggest that these activities, linked to a successful reduction in inflammatory processes, may support, in part, its ethnopharmacological use. PMID:22424456

  3. Zircon evidence for a ~200 k.y. supereruption-related thermal flare-up in the Miocene southern Black Mountains, western Arizona, USA

    NASA Astrophysics Data System (ADS)

    McDowell, Susanne M.; Miller, Calvin F.; Mundil, Roland; Ferguson, Charles A.; Wooden, Joseph L.

    2014-07-01

    The Silver Creek caldera (southern Black Mountains, western Arizona) is the source of the 18.8 Ma, >700 km3 Peach Spring Tuff (PST) supereruption, the largest eruption generated in the Colorado River Extensional Corridor (CREC) of the southwestern United States. Within and immediately surrounding the caldera is a sequence of volcanics and intrusions ranging in age from ~19 to 17 Ma. These units offer a record of magmatic processes prior to, during, and immediately following the PST eruption. To investigate the thermal evolution of the magmatic center that produced the PST, we applied a combination of Ti-in-zircon thermometry, zircon saturation thermometry, and high-precision U-Pb CA-TIMS zircon dating to representative pre- and post-supereruption volcanic and intrusive units from the caldera and its environs. Similar to intracaldera PST zircons, zircons from a pre-PST trachytic lava (19 Ma) and a post-PST caldera intrusion (18.8 Ma) yield exceptionally high-Ti concentrations (most >20 ppm, some up to nearly 60 ppm), corresponding to calculated temperatures that exceed 900 °C. In these units, Ti-in-zircon temperatures typically surpass zircon saturation temperatures (ZSTs), suggesting the entrainment of zircon that had grown in hotter environments within the magmatic system. Titanium concentrations in younger volcanic and intrusive units (~18.7-17.5 Ma) decline through time, corresponding to an average cooling rate of 10-3.5 °C/year. The ~200 k.y. thermal peak evident at Silver Creek caldera is spatially limited: elsewhere in the Miocene record of the northern CREC, Ti-in-zircon concentrations and ZSTs are much lower, suggesting that felsic magmas were generally substantially cooler.

  4. Estimated range of black carbon dry deposition and the related snow albedo reduction over Himalayan glaciers during dry pre-monsoon periods

    NASA Astrophysics Data System (ADS)

    Yasunari, Teppei J.; Tan, Qian; Lau, K.-M.; Bonasoni, Paolo; Marinoni, Angela; Laj, Paolo; Ménégoz, Martin; Takemura, Toshihiko; Chin, Mian

    2013-10-01

    One of the major factors attributed to the accelerated melting of Himalayan glaciers is the snow darkening effect of atmospheric black carbon (BC). The BC is the result of incomplete fossil fuel combustion from sources such as open biomass burning and wood burning cooking stoves. One of the key challenges in determining the darkening effect is the estimation uncertainty of BC deposition (BCD) rate on surface snow cover. Here we analyze the variation of BC dry deposition in seven different estimates based on different dry deposition methods which include different atmospheric forcings (observations and global model outputs) and different spatial resolutions. The seven simulations are used to estimate the uncertainty range of BC dry deposition over the southern Himalayas during pre-monsoon period (March-May) in 2006. Our results show BC dry deposition rates in a wide range of 270-4700 μg m-2 during the period. Two global models generate higher BC dry deposition rates due to modeled stronger surface wind and simplification of complicated sub-grid surface conditions in this region. Using ice surface roughness and observation-based meteorological data, we estimate a better range of BC dry deposition rate of 900-1300 μg m-2. Under dry and highly polluted conditions, aged snow and sulfate-coated BC are expected to possibly reduce visible albedo by 4.2-5.1%. Our results suggest that for estimating aerosol-induced snow darkening effects of Himalaya snowpacks using global and regional models, realistic physical representation of ice or snow surface roughness and surface wind speed are critical in reducing uncertainties on the estimate of BC deposition over snow surface.

  5. Host location, survival and fecundity of the Oriental rat flea Xenopsylla cheopis (Siphonaptera: Pulicidae) in relation to black rat Rattus rattus (Rodentia: Muridae) host age and sex.

    PubMed

    Mears, S; Clark, F; Greenwood, M; Larsen, K S

    2002-10-01

    Host choice and fecundity are two factors that may contribute to the variation in flea counts observed when assessing the potential risk of flea-borne transmission of pathogens from rodents to humans. Using the black rat, Rattus rattus Linnaeus, as host the effects of age and sex on host choice and fecundity of the Oriental rat flea, Xenopsylla cheopis Rothschild, were examined experimentally at 25 degrees C and 80% rh. During the first two days of emergence from cocoons, female fleas dominated the sex ratio by 4:1 but from the third day onwards this switched to a male-dominated sex ratio of 4:1. The sex of the flea did not influence their host-seeking behaviour. Newly emerged fleas of both sexes were not influenced by the rat's presence and at seven days old both sexes demonstrated similar levels of attraction toward the rat host. The sex of the rat did not affect flea host-seeking behaviour. There was a 50-70% decline in the initial number of adult fleas during the first week after their release onto a rat host, and this decline was greatest on juvenile rats. Flea fecundity was also significantly lower on juvenile rat hosts but no differences due to the sex of the rat were observed. This experimental study supports the hypothesis that differences in flea count due to host sex, reported in field surveys, result from sexual differences in host behaviour and not from discriminatory host-seeking behaviour by X. cheopis. Differences in flea count due to host age may be affected by differences in X. cheopis fecundity, which may itself be mediated by host behaviour such as grooming.

  6. Psycho-social factors related to willingness to use pre-exposure prophylaxis for HIV prevention among Black men who have sex with men attending a community event

    PubMed Central

    Eaton, Lisa A.; Driffin, Daniel D.; Smith, Harlan; Conway-Washington, Christopher; White, Denise; Cherry, Chauncey

    2015-01-01

    OBJECTIVES In the US, Black men who have sex with men (BMSM) are disproportionately affected by HIV/AIDS. Pre-exposure prophylaxis (PrEP) holds tremendous promise for curbing the HIV/AIDS epidemic among these men. However, many psycho-social components must be addressed in order to effectively implement this prevention tool among BMSM. METHODS We assessed PrEP knowledge and use, health care access experiences, race-based medical mistrust, sexual partners and behaviors, and drug and alcohol use among 699 men attending a community event in the southeastern US. We used generalized linear modeling to assess factors associated with their willingness to use PrEP. RESULTS Three hundred ninety-eight men reported being BMSM and HIV negative status. Among these men, 60% reported being willing to use PrEP. Lack of being comfortable with talking to a health care provider about having sex with men, not having discussed having sex with a man with a health care provider, race-based medical mistrust, and alcohol consumption and substance use were all identified as barriers to willingness to use PrEP. Sexual risk taking, including number of sex partners and STI diagnosis, was not associated with willingness to use PrEP. CONCLUSIONS Findings from the current paper demonstrate the importance of acknowledging the role of various psycho-social factors in the uptake of PrEP. It is imperative that we prioritize research into better understanding these barriers as the failure to do so will impede the tremendous potential of this prevention technology. PMID:25001553

  7. Multipole moments of bumpy black holes

    SciTech Connect

    Vigeland, Sarah J.

    2010-11-15

    General relativity predicts the existence of black holes, compact objects whose spacetimes depend only on their mass, spin, and charge in vacuum (the 'no-hair' theorem). As various observations probe deeper into the strong fields of black hole candidates, it is becoming possible to test this prediction. Previous work suggested that such tests can be performed by measuring whether the multipolar structure of black hole candidates has the form that general relativity demands, and introduced a family of 'bumpy black hole' spacetimes to be used for making these measurements. These spacetimes have generalized multipoles, where the deviation from the Kerr metric depends on the spacetime's 'bumpiness'. In this paper, we show how to compute the Geroch-Hansen moments of a bumpy black hole, demonstrating that there is a clean mapping between the deviations used in the bumpy black hole formalism and the Geroch-Hansen moments. We also extend our previous results to define bumpy black holes whose current moments, analogous to magnetic moments of electrodynamics, deviate from the canonical Kerr value.

  8. Black Hole Solutions and Pair Creation of Black Holes in Three, Four and Higher Dimensional Spacetimes

    NASA Astrophysics Data System (ADS)

    Dias, Oscar J. C.

    2004-10-01

    Black holes, first found as solutions of Einstein's General Relativity, are important in astrophysics, since they result from the gravitational collapse of a massive star or a cluster of stars, and in physics since they reveal properties of the fundamental physics, such as thermodynamic and quantum properties of gravitation. In order to better understand the black hole physics we need exact solutions that describe one or more black holes. In this thesis we study exact solutions in three, four and higher dimensional spacetimes. The study in 3-dimensions is important due to the simplification of the problem, while the discussion in higher dimensions is essential due to the fact that many theories indicate that extra dimensions exist in our universe. In this thesis, in any of the dimensions mentioned above, we study exact solutions with a single black hole and exact solutions that describe a pair of uniformly accelerated black holes (C-metric), with the acceleration source being well identified. This later solutions are then used to study in detail the quantum process of black hole pair creation in an external field. We also compute the gravitational radiation released during this pair creation process. KEYWORDS: Exact black hole solutions; Pair of accelerated black holes, C-metric, Ernst solution; Pair creation of black holes; Gravitational radiation; D-dimensional spacetimes; Cosmological constant backgrounds.

  9. Gauge dependence and self-force from Galilean to Einsteinian free fall, compact stars falling into black holes, Hawking radiation and the Pisa tower at the general relativity centennial

    NASA Astrophysics Data System (ADS)

    Spallicci, Alessandro D. A. M.; van Putten, Maurice H. P. M.

    2016-08-01

    Obviously, in Galilean physics, the universality of free fall implies an inertial frame, which in turns implies that the mass m of the falling body is omitted (because it is a test mass; put otherwise, the center of mass of the system coincides with the center of the main, and fixed, mass M; or else, we consider only a homogeneous gravitational field). Conversely, an additional (in the opposite or same direction) acceleration proportional to m/M would rise either for an observer at the center of mass of the system, or for an observer at a fixed distance from the center of mass of M. These elementary, but overlooked, considerations fully respect the equivalence principle (EP) and the (local) identity of an inertial or a gravitational pull for an observer in the Einstein cabin. They value as fore-runners of the self-force and gauge dependency in general relativity. Because of its importance in teaching and in the history of physics, coupled to the introductory role to Einstein’s EP, the approximate nature of Galilei’s law of free fall is explored herein. When stepping into general relativity, we report how the geodesic free fall into a black hole was the subject of an intense debate again centered on coordinate choice. Later, we describe how the infalling mass and the emitted gravitational radiation affect the free fall motion of a body. The general relativistic self-force might be dealt with to perfectly fit into a geodesic conception of motion. Then, embracing quantum mechanics, real black holes are not classical static objects any longer. Free fall has to handle the Hawking radiation, and leads us to new perspectives on the varying mass of the evaporating black hole and on the varying energy of the falling mass. Along the paper, we also estimate our findings for ordinary masses being dropped from a Galilean or Einsteinian Pisa-like tower with respect to the current state of the art drawn from precise measurements in ground and space laboratories, and to the

  10. Numerical simulations of black-hole spacetimes

    NASA Astrophysics Data System (ADS)

    Chu, Tony

    This thesis covers various aspects of the numerical simulation of black-hole spacetimes according to Einstein's general theory of relativity, using the Spectral Einstein Code developed by the Caltech-Cornell-CITA collaboration. The first topic is improvement of binary-black-hole initial data. One such issue is the construction of binary-black-hole initial data with nearly extremal spins that remain nearly constant during the initial relaxation in an evolution. Another concern is the inclusion of physically realistic tidal deformations of the black holes to reduce the high-frequency components of the spurious gravitational radiation content, and represents a first step in incorporating post-Newtonian results in constraint-satisfying initial data. The next topic is the evolution of black-hole binaries and the gravitational waves they emit. The first spectral simulation of two inspiralling black holes through merger and ringdown is presented, in which the black holes are nonspinning and have equal masses. This work is extended to perform the first spectral simulations of two inspiralling black holes with moderate spins and equal masses, including the merger and ringdown. Two configurations are considered, in which both spins are either anti-aligned or aligned with the orbital angular momentum. Highly accurate gravitational waveforms are computed for all these cases, and are used to calibrate waveforms in the effective-one-body model. The final topic is the behavior of quasilocal black-hole horizons in highly dynamical situations. Simulations of a rotating black hole that is distort ed by a pulse of ingoing gravitational radiation are performed. Multiple marginally outer trapped surfaces are seen to appear and annihilate with each other during the evolution, and the world tubes th ey trace out are all dynamical horizons. The dynamical horizon and angular momentum flux laws are evaluated in this context, and the dynamical horizons are contrasted with the event horizon

  11. Early black hole signals at the LHC

    SciTech Connect

    Koch, Ben; Bleicher, Marcus; Stoecker, Horst

    2007-10-26

    The production of mini black holes due to large extra dimensions is a speculative but possible scenario. We survey estimates for di-jet suppression, and multi-mono-jet emission due to black hole production. We further look for a possible sub-scenario which is the formation of a stable or meta-stable black hole remnant (BHR). We show that the beauty of such objects is, that they are relatively easy to observe, even in the early phase of LHC running.

  12. Central black hole masses of galaxies

    NASA Astrophysics Data System (ADS)

    Fan, Jun-Hui

    2003-11-01

    In this paper, the stellar velocity dispersions in the host galaxies are used to estimate the central black hole masses for a sample of elliptical galaxies. We find that the central black hole masses are in the range of 10(5.5-9.5)Modot. Based on the estimated masses in this paper and those by Woo & Urry (2002) and the measured host galaxy absolute magnitude, a relation, log (MBH/Modot) = -(0.25±4.3×10-3)MR + (2.98±0.208) is found for central black hole mass and the host galaxy magnitude. Some discussions are presented.

  13. Early black hole signals at the LHC

    NASA Astrophysics Data System (ADS)

    Koch, Ben; Bleicher, Marcus; Stöcker, Horst

    2007-10-01

    The production of mini black holes due to large extra dimensions is a speculative but possible scenario. We survey estimates for di-jet suppression, and multi-mono-jet emission due to black hole production. We further look for a possible sub-scenario which is the formation of a stable or meta-stable black hole remnant (BHR). We show that the beauty of such objects is, that they are relatively easy to observe, even in the early phase of LHC running.

  14. Three charge supertubes and black hole hair

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Kraus, Per

    2004-08-01

    We construct finite size, supersymmetric, tubular D-brane configurations with three charges, two angular momenta and several brane dipole moments. In type IIA string theory these are tubular configurations with D0, D4 and F1 charge, as well as D2, D6 and NS5 dipole moments. These multicharge generalizations of supertubes might have interesting consequences for the physics of the D1-D5-P black hole. We study the relation of the tubes to the spinning Breckenridge-Myers-Peet-Vafa black hole, and find that they have properties consistent with describing some of the hair of this black hole.

  15. FORCE-FEEDING BLACK HOLES

    SciTech Connect

    Begelman, Mitchell C.

    2012-04-10

    We propose that the growth of supermassive black holes is associated mainly with brief episodes of highly super-Eddington infall of gas ({sup h}yperaccretion{sup )}. This gas is not swallowed in real time, but forms an envelope of matter around the black hole that can be swallowed gradually, over a much longer timescale. However, only a small fraction of the black hole mass can be stored in the envelope at any one time. We argue that any infalling matter above a few percent of the hole's mass is ejected as a result of the plunge in opacity at temperatures below a few thousand degrees kelvin, corresponding to the Hayashi track. The speed of ejection of this matter, compared to the velocity dispersion {sigma} of the host galaxy's core, determines whether the ejected matter is lost forever or returns eventually to rejoin the envelope, from which it can be ultimately accreted. The threshold between matter recycling and permanent loss defines a relationship between the maximum black hole mass and {sigma} that resembles the empirical M{sub BH}-{sigma} relation.

  16. Uniformly accelerated black holes

    NASA Astrophysics Data System (ADS)

    Letelier, Patricio S.; Oliveira, Samuel R.

    2001-09-01

    The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

  17. What Black Educators are Saying.

    ERIC Educational Resources Information Center

    Wright, Nathan, Jr., Ed.

    Contents of this book are comprised of five groups of articles: Part I. The Black Educator: "Education for black humanism; a way of approaching it," Preston Wilcox; "The new black dimension in our society," Olivia Pearl Stokes; "The black teacher and black Power," Leslie Campbell; and, "The difference," Leslie Campbell. Part II. The White…

  18. Asymptotic black holes

    NASA Astrophysics Data System (ADS)

    Ho, Pei-Ming

    2017-04-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  19. Destruction and recreation of black holes

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Even though the existence of the gravitationally collapsed concentrations of matter in space known as ‘black holes’ is accepted at all educational levels in our society, the basis for the black hole concept is really only the result of approximate calculations done over 40 years ago. The concept of the black hole is an esoteric subject, and recently the mathematical and physical frailties of the concept have come to light in an interesting round of theoretical shuffling. The recent activity in theorizing about black holes began about 10 years ago, when Cambridge University mathematican Stephen Hawking calculated that black holes could become unstable by losing mass and thus ‘evaporate.’ Hawking's results were surprisingly well received, considering the lack of theoretical understanding of the relations between quantum mechanics and relativity. (There is no quantized theory of gravitation, even today.) Nonetheless, his semiclassical calculations implied that the rate of ‘evaporation’ of a black hole would be slower than the rate of degradation of the universe. In fact, based on these and other calculations, the British regard Hawking as ‘the nearest thing we have to a new Einstein’ [New Scientist, Oct. 9, 1980]. Within the last few months, Frank Tipler, provocative mathematical physicist at the University of Texas, has reexamined Hawking's calculations [Physical Review Letters, 45, 941, 1980], concluding, in simple terms, (1) that because of possible vital difficulties in the assumptions, the very concept of black holes could be wrong; (2) that Hawkings' evaporation hypothesis is so efficient that a black hole once created must disappear in less than a second; or (3) that he, Tipler, may be wrong. The latter possibility has been the conclusion of physicist James Bardeen of the University of Washington, who calculated that black hole masses do evaporate but they do so according to Hawking's predicted rate and that Tipler's findings cause only a second

  20. Feasibility study to develop a marketing plan and strategy for increasing the participation of minority business enterprises and black colleges and universities in energy-related industries. Final report

    SciTech Connect

    Not Available

    1983-01-31

    This study was designed to identify and test an alternative method for more effective means of involving Minority Business Enterprises (MBEs) and historically Black colleges and universities (HBUs) in energy-related business opportunities. Based upon the analysis of MBE and HBCU technical assistance programs, DOD's DOE's, and TVA's procurement processes and the results of the test used to validate the adaptability of a performance tested alternative marketing system to energy-related industries. Based on the findings and conclusions of this study and in order to meet the objectives of: (1) increasing participation of MBEs and HBCUs in TVA and energy-related industries; (2) ensuring that the statutory objectives of Title VI of the Civil Rights Act of 1964 and Public Law 95-507 are achieved in the public and private energy market sectors; and (3) meeting President Reagan's goal of realizing $22 billion in minority contracts within the next three years, BTW recommends that the Portfolio System be adapted, demonstrated, installed and deployed in large-scale, complex, energy-related research and development facilities and power utilities' procurement programs.

  1. Local temperature for dynamical black holes

    SciTech Connect

    Hayward, Sean A.; Di Criscienzo, R.; Nadalini, M.; Vanzo, L.; Zerbini, S.

    2009-05-01

    A local Hawking temperature was recently derived for any future outer trapping horizon in spherical symmetry, using a Hamilton-Jacobi tunneling method, and is given by a dynamical surface gravity as defined geometrically. Descriptions are given of the operational meaning of the temperature, in terms of what observers measure, and its relation to the usual Hawking temperature for static black holes. Implications for the final fate of an evaporating black hole are discussed.

  2. Infectious hypodermal and hematopoietic necrosis virus (IHHNV)-related sequences in the genome of the black tiger prawn Penaeus monodon from Africa and Australia.

    PubMed

    Tang, Kathy F J; Lightner, Donald V

    2006-06-01

    We found an infectious hypodermal and hematopoietic necrosis virus (IHHNV)-related sequence within the shrimp genome in populations of Penaeus monodon from Africa and Australia. IHHNV is a single-stranded DNA virus that has caused severe mortality and stunted growth in penaeid shrimp. Recently, IHHNV-related sequences were found in samples of P. monodon from Madagascar and Tanzania. These sequences vary considerably (14 and 8%, respectively) from that of IHHNV found in association with viral epidemics. Laboratory bioassays were carried out with P. monodon and Litopenaeus vannamei to determine if either of these IHHNV-related sequences is infectious. We used juvenile and adult P. monodon containing the virus-related sequences from four geographic regions to generate inocula and tissues for feeding. Specific pathogen free P. monodon and L. vannamei were used as indicator shrimp. During the 2-4 week bioassays, none of the indicator shrimp showed signs of infection or disease. Results of both PCR assays and histological examination of the indicator shrimp were negative for IHHNV infection, indicating that the Africa type IHHNV-related sequences are not infectious. With the shrimp containing the Madagascar type IHHNV-related sequence (designated as type A), we performed genome walking at the 3' end of the virus-related sequence and found that this virus-related sequence is part of the P. monodon genome. A fragment of 1.9 kb flanking sequence was cloned and sequenced. Sequence analysis showed that this flanking sequence contains shrimp microsatellite DNA. Also, its translated amino acid sequence was highly similar to a retrotransposon. This result provides molecular evidence that the type A IHHNV-related sequence is shrimp DNA. This sequence was found in the P. monodon collected from Africa and Australia.

  3. Black hole as a magnetic monopole within exponential nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Kruglov, S. I.

    2017-03-01

    We perform the gauge covariant quantization of the exponential model of nonlinear electrodynamics. Magnetically charged black holes, in the framework of our model are considered, and the regular black hole solution is obtained in general relativity. The asymptotic black hole solution at r → ∞ is found. We calculate the magnetic mass of the black hole and the metric function which are expressed via the parameter β of the model and the magnetic charge. The thermodynamic properties and thermal stability of regular black holes are analysed. We calculate the Hawking temperature of black holes and their heat capacity at the constant magnetic charge. We find a point where the temperature changes the sign that corresponds to the first-order phase transition. It is shown that at critical point, where the heat capacity diverges, there is a phase transition of the second-order. We obtain the parameters of the model when the black hole is stable.

  4. Phanerozoic black shales and the Wilson Cycle

    NASA Astrophysics Data System (ADS)

    Trabucho-Alexandre, J.; Hay, W. W.; de Boer, P. L.

    2011-09-01

    The spatial and temporal distribution of black shales is related to the development of the environments in which they accumulate and to a propitious combination of environmental variables. Whereas much has been done in recent years to improve our understanding of the mechanisms behind the temporal distribution of black shales in the Phanerozoic, the interpretation of the palaeogeographical distribution of black shales is still dominated by an oversimplistic set of three uniformitarian depositional models that do not capture the complexity and dynamics of environments of black shale accumulation. These three models, the restricted circulation, the (open) ocean oxygen minimum and the continental shelf models, are in fact a uniformitarian simplification of the variety of depositional environments that arise and coexist throughout the course of a basin's Wilson Cycle, i.e. the dynamic sequence of events and stages that characterise the evolution of an ocean basin, from the opening continental rift to the closing orogeny. We examine the spatial distribution of black shales in the context of the Wilson Cycle using examples from the Phanerozoic. It is shown that the geographical distribution of black shales, their position in the basin infill sequence and their nature (e.g. type of organic matter, lithology) depend on basin evolution because the latter controls the development of sedimentary environments where black shales may be deposited.

  5. Primordial black holes in globular clusters

    NASA Technical Reports Server (NTRS)

    Sigurdsson, Steinn; Hernquist, Lars

    1993-01-01

    It has recently been recognized that significant numbers of medium-mass back holes (of order 10 solar masses) should form in globular clusters during the early stages of their evolution. Here we explore the dynamical and observational consequences of the presence of such a primordial black-hole population in a globular cluster. The holes initially segregate to the cluster cores, where they form binary and multiple black-hole systems. The subsequent dynamical evolution of the black-hole population ejects most of the holes on a relatively short timescale: a typical cluster will retain between zero and four black holes in its core, and possibly a few black holes in its halo. The presence of binary, triple, and quadruple black-hole systems in cluster cores will disrupt main-sequence and giant stellar binaries; this may account for the observed anomalies in the distribution of binaries in globular clusters. Furthermore, tidal interactions between a multiple black-hole system and a red giant star can remove much of the red giant's stellar envelope, which may explain the puzzling absence of larger red giants in the cores of some very dense clusters.

  6. Attractiveness of black Shannon trap for phlebotomines.

    PubMed

    Galati, E A; Nunes, V L; Dorval, M E; Cristaldo, G; Rocha, H C; Gonçalves-Andrade, R M; Naufel, G

    2001-07-01

    A white Shannon-type trap was used for captures of female sand flies in the search for natural infection with flagellates, however, due to its low productivity and as a large number of phlebotomines settled on the researchers' black clothes, we decided to compare the relative attractiveness of black and white Shannon-type traps for sand flies. Several pairs of black and white traps were placed side by side in front of caves in four areas in the Serra da Bodoquena, Bonito county, State of Mato Grosso do Sul, Brazil, for a total of 12 observations and 44 h of capture. The experiment resulted in 889 phlebotomines captured, 801 on the black and 88 on the white trap, representing 13 species. The hourly Williams' means were 8.67 and 1.24, respectively, and the black/white ratio was 7.0:1.0. Lutzomyia almerioi, an anthropophilic species closely associated with caves, was predominant (89%). Only two other species, Nyssomyia whitmani and Psathyromyia punctigeniculata, also anthropophilic, were significantly attracted to the black rather than to the white trap (chi(2) test; p < or = 0.01). The difference between the diversity index of the two traps was not significant at level 0.05. The black trap in these circumstances was much more productive than the white, especially for anthropophilic species.

  7. Black hole entanglement and quantum error correction

    NASA Astrophysics Data System (ADS)

    Verlinde, Erik; Verlinde, Herman

    2013-10-01

    It was recently argued in [1] that black hole complementarity strains the basic rules of quantum information theory, such as monogamy of entanglement. Motivated by this argument, we develop a practical framework for describing black hole evaporation via unitary time evolution, based on a holographic perspective in which all black hole degrees of freedom live on the stretched horizon. We model the horizon as a unitary quantum system with finite entropy, and do not postulate that the horizon geometry is smooth. We then show that, with mild assumptions, one can reconstruct local effective field theory observables that probe the black hole interior, and relative to which the state near the horizon looks like a local Minkowski vacuum. The reconstruction makes use of the formalism of quantum error correcting codes, and works for black hole states whose entanglement entropy does not yet saturate the Bekenstein-Hawking bound. Our general framework clarifies the black hole final state proposal, and allows a quantitative study of the transition into the "firewall" regime of maximally mixed black hole states.

  8. Galaxy Bulges and Their Massive Black Holes: A Review

    NASA Astrophysics Data System (ADS)

    Graham, Alister W.

    With references to both key and often forgotten pioneering works, this article starts by presenting a review into how we came to believe in the existence of massive black holes at the centers of galaxies. It then presents the historical development of the near-linear (black hole)-(host spheroid) mass relation, before explaining why this has recently been dramatically revised. Past disagreement over the slope of the (black hole)-(velocity dispersion) relation is also explained, and the discovery of sub-structure within the (black hole)-(velocity dispersion) diagram is discussed. As the search for the fundamental connection between massive black holes and their host galaxies continues, the competing array of additional black hole mass scaling relations for samples of predominantly inactive galaxies are presented.

  9. Social Media Use and HIV-Related Risk Behaviors in Young Black and Latino Gay and Bi Men and Transgender Individuals in New York City: Implications for Online Interventions.

    PubMed

    Patel, Viraj V; Masyukova, Mariya; Sutton, Desmond; Horvath, Keith J

    2016-04-01

    Urban young men who have sex with men (YMSM) and transgender women continue to experience high rates of new HIV infections in the USA, yet most of this population is not reached by current prevention interventions. The rate of Internet and social media use among youth is high. However, continually updated understanding of the associations between social media access and use and HIV risk behaviors is needed to reach and tailor technology-delivered interventions for those most vulnerable to HIV-racially and ethnically diverse urban YMSM and transgender persons. Thus, we conducted an in-person, venue-based cross-sectional survey among young gay, bisexual, and transgender individuals at locations primarily visited by Black and Latino gay and bisexual and transgender individuals in New York City to understand social media use and how it may relate to HIV risk behaviors to inform social media-based interventions. Among 102 primarily Black and Latino gay and bisexual men (75.5 %) and transgender women (19.6 %), over 90 % were under 30 years of age, 18.6 % reported homelessness in the past 6 months, and 10.8 % reported having HIV. All participants used social media, most accessed these platforms most often via a mobile device (67.6 %) and most logged on multiple times per day (87.3 %). Participants used social media to seek sex partners (56.7 %), exchange sex for money or clothes (19.6 %), and exchange sex for drugs (9.8 %). These results confirm prior studies demonstrating the feasibility of using social media platforms to reach at-risk, urban youth. Of particular concern is the association between recent STI and exchanging sex for money/clothes and drugs. Interventions using social media for young, urban minority MSM and transgender populations should incorporate risk reduction modules addressing exchange partners and promote frequent and regular HIV/STI testing.

  10. In situ measurements of particle number concentration, chemically resolved size distributions and black carbon content of traffic-related emissions on German motorways, rural roads and in city traffic

    NASA Astrophysics Data System (ADS)

    Schneider, J.; Kirchner, U.; Borrmann, S.; Vogt, R.; Scheer, V.

    2008-06-01

    In-situ measurements of various properties of traffic-related aerosol particles have been performed with a mobile laboratory. The measured aerosol quantities include particle chemical composition (sulfate, nitrate, total organic matter, ammonium, black carbon) as well as particle size distributions covering diameters from 10 to 300 nm, and total particle number density. Additionally, gas phase emissions (CO2, NO, NO2) were monitored. We performed six measurement drives in the vicinity of the city of Aachen (population ca. 260,000) at 50.8°N, 6.1°E in Germany on motorways, rural roads, and in the inner city of Aachen in June 2005. The results indicate that the main influence of traffic on the aerosol properties results in soot particles coated with organic matter, having a modal diameter around 100 nm ("soot mode"). The abundance of these particles was found to be highest in the inner city traffic. Nucleation mode particles (around 30 nm) have been observed occasionally during truck chasings on motorways. These particles consisted mainly of organic compounds but included possibly also a sulfuric acid core. Data observed under "motorway background" conditions were similar to the rural regional road data. Highest number concentrations have been observed during truck chasings. Comparison between non-refractory (here with respect to 600 °C) and total particle volume indicated a higher contribution of refractory material under all traffic-influenced conditions compared to rural road data. Fuel specific emission ratios were derived for a subset of 18 truck-chasing experiments, yielding (8.3±5.8)×1015 kg-1 for particle number, 224±136 mg kg-1 for black carbon, 125±125 mg kg-1 for organic matter, 17±12 g kg-1 for NO and 18±14 g kg-1 for NOx (mean values and standard deviations).

  11. Revisiting Black Holes as Dark Matter

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2017-02-01

    Could dark matter be made of intermediate-mass black holes formed in the beginning of the universe? A recent study takes a renewed look at this question.Galactic LurkersThe nature of dark matter has long been questioned, but the recent discovery of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory (LIGO) has renewed interest in the possibility that dark matter could consist of primordial black holes in the mass range of 101000 solar masses.The relative amounts of the different constituents of the universe. Dark matter makes up roughly 27%. [ESA/Planck]According to this model, the extreme density of matter present during the universes early expansion led to the formation of a large number of intermediate-mass black holes. These black holes now hide in the halos of galaxies, constituting the mass that weve measured dynamically but remains unseen.LIGOs first gravitational-wave detection revealed the merger of two black holes that were both tens of solar masses in size. If primordial black holes are indeed a major constituent of dark matter, then LIGOs detection is consistent with what we would expect to find: occasional mergers of the intermediate-mass black holes that formed in the early universe and now lurk in galactic halos.Quasar MicrolensingTheres a catch, however. If there truly were a large number of intermediate-mass primordial black holes hiding in galactic halos, they wouldnt go completely unnoticed: we would see signs of their presence in the gravitational microlensing of background quasars. Unseen primordial black holes in a foreground galaxy could cause an image of a background quasar to briefly brighten which would provide us with clear evidence of such black holes despite our not being able to detect them directly.A depiction of quasar microlensing (click for a closer look!). The microlensing object in the foreground galaxy could be a star (as depicted), a primordial black hole, or any other compact object. [NASA

  12. Black holes in binary stellar systems and galactic nuclei

    NASA Astrophysics Data System (ADS)

    Cherepashchuk, A. M.

    2014-04-01

    In the last 40 years, following pioneering papers by Ya B Zeldovich and E E Salpeter, in which a powerful energy release from nonspherical accretion of matter onto a black hole (BH) was predicted, many observational studies of black holes in the Universe have been carried out. To date, the masses of several dozen stellar-mass black holes (M_BH = (4{-}20) M_\\odot) in X-ray binary systems and of several hundred supermassive black holes (M_BH = (10^{6}{-}10^{10}) M_\\odot) in galactic nuclei have been measured. The estimated radii of these massive and compact objects do not exceed several gravitational radii. For about ten stellar-mass black holes and several dozen supermassive black holes, the values of the dimensionless angular momentum a_* have been estimated, which, in agreement with theoretical predictions, do not exceed the limiting value a_* = 0.998. A new field of astrophysics, so-called black hole demography, which studies the birth and growth of black holes and their evolutionary connection to other objects in the Universe, namely stars, galaxies, etc., is rapidly developing. In addition to supermassive black holes, massive stellar clusters are observed in galactic nuclei, and their evolution is distinct from that of supermassive black holes. The evolutionary relations between supermassive black holes in galactic centers and spheroidal stellar components (bulges) of galaxies, as well as dark-matter galactic haloes are brought out. The launch into Earth's orbit of the space radio interferometer RadioAstron opened up the real possibility of finally proving that numerous discovered massive and highly compact objects with properties very similar to those of black holes make up real black holes in the sense of Albert Einstein's General Relativity. Similar proofs of the existence of black holes in the Universe can be obtained by intercontinental radio interferometry at short wavelengths \\lambda \\lesssim 1 mm (the international program, Event Horizon Telescope).

  13. Black Holes Have Simple Feeding Habits

    NASA Astrophysics Data System (ADS)

    2008-06-01

    The biggest black holes may feed just like the smallest ones, according to data from NASA’s Chandra X-ray Observatory and ground-based telescopes. This discovery supports the implication of Einstein's relativity theory that black holes of all sizes have similar properties, and will be useful for predicting the properties of a conjectured new class of black holes. The conclusion comes from a large observing campaign of the spiral galaxy M81, which is about 12 million light years from Earth. In the center of M81 is a black hole that is about 70 million times more massive than the Sun, and generates energy and radiation as it pulls gas in the central region of the galaxy inwards at high speed. In contrast, so-called stellar mass black holes, which have about 10 times more mass than the Sun, have a different source of food. These smaller black holes acquire new material by pulling gas from an orbiting companion star. Because the bigger and smaller black holes are found in different environments with different sources of material to feed from, a question has remained about whether they feed in the same way. Using these new observations and a detailed theoretical model, a research team compared the properties of M81's black hole with those of stellar mass black holes. The results show that either big or little, black holes indeed appear to eat similarly to each other, and produce a similar distribution of X-rays, optical and radio light. AnimationMulti-wavelength Images of M81 One of the implications of Einstein's theory of General Relativity is that black holes are simple objects and only their masses and spins determine their effect on space-time. The latest research indicates that this simplicity manifests itself in spite of complicated environmental effects. "This confirms that the feeding patterns for black holes of different sizes can be very similar," said Sera Markoff of the Astronomical Institute, University of Amsterdam in the Netherlands, who led the study

  14. TOPICAL REVIEW: Quasinormal modes of black holes and black branes

    NASA Astrophysics Data System (ADS)

    Berti, Emanuele; Cardoso, Vitor; Starinets, Andrei O.

    2009-08-01

    Quasinormal modes are eigenmodes of dissipative systems. Perturbations of classical gravitational backgrounds involving black holes or branes naturally lead to quasinormal modes. The analysis and classification of the quasinormal spectra require solving non-Hermitian eigenvalue problems for the associated linear differential equations. Within the recently developed gauge-gravity duality, these modes serve as an important tool for determining the near-equilibrium properties of strongly coupled quantum field theories, in particular their transport coefficients, such as viscosity, conductivity and diffusion constants. In astrophysics, the detection of quasinormal modes in gravitational wave experiments would allow precise measurements of the mass and spin of black holes as well as new tests of general relativity. This review is meant as an introduction to the subject, with a focus on the recent developments in the field.

  15. Recruiting Blacks into Journalism.

    ERIC Educational Resources Information Center

    Tipton, Leonard; And Others

    Despite significant progress in the recruitment of black journalists, adequate representation of blacks in newsrooms remains an acute concern. The results of (1) statistical monitoring by organizations such as the Newspaper Fund, (2) searching of trade press and academic journal articles for insights into the problem, (3) an open-ended…

  16. Cultural Vignette: Black Americans.

    ERIC Educational Resources Information Center

    Bell, Ida; And Others

    Developed as part of a multicultural research project conducted in the San Diego Community College District, this booklet presents the findings of an eight-member research team about various elements of Black American culture and history. The booklet begins with a brief history of Black Americans from the time of the arrival of the first slaves to…

  17. Black Craftsmen Through History.

    ERIC Educational Resources Information Center

    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…

  18. Black Studies Year One.

    ERIC Educational Resources Information Center

    Long, Richard A.

    Though Dubois tried to begin a series of scientific studies on the Negro problem in America more than 70 years ago, only recently have attempts been made to present a true history of the Black man in institutions of higher learning. Until that time, the experience of the Black man was defined in Euro-American terms, or in most cases was completely…

  19. Lexicon of Black English.

    ERIC Educational Resources Information Center

    Dillard, J. L.

    The purpose of this volume is to demonstrate that the fields of linguistics, dialectology, language education, and early reading would be well served by a word book of the Black English vernacular. Chapters are devoted to discussion of the social significance of a lexicon of Black English vernacular, the terminology of sex and lovemaking, religion…

  20. Black Families. Interdisciplinary Perspectives.

    ERIC Educational Resources Information Center

    Cheatham, Harold E., Ed.; Stewart, James B., Ed.

    Since the early 1960s, the black family has been characterized as pathological. This six-part collection of 18 research studies presents alternative approaches to understanding the special characteristics of black families. Part I, "Theoretical and Methodological Perspectives," comprises a comparison of the pioneering work of W. E. B. Du…

  1. Neoliberalism and Black Education.

    ERIC Educational Resources Information Center

    Rich, John Martin

    1986-01-01

    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…

  2. Protecting Black Girls

    ERIC Educational Resources Information Center

    Morris, Monique W.

    2016-01-01

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

  3. Fifty shades of black

    NASA Astrophysics Data System (ADS)

    Cartwright, Jon

    2015-11-01

    Creating dark materials that prevent reflections has become hot competition recently, with Guinness World Records having to keep revising the darkest substance yet created. But depending on who's asking, the best black may not be the blackest black, as Jon Cartwright discovers.

  4. The Black College Mystique

    ERIC Educational Resources Information Center

    Willie, Charles V.; Reddick, Richard J.; Brown, Ronald

    2005-01-01

    This study compares the culture of black colleges and universities a generation ago with those that exist today, and makes projections into the future, based on a comprehensive review of professional literature and an analysis of the management skills of contemporary black college leaders. The book considers the assets and liabilities of…

  5. The Black Woman's Burden

    ERIC Educational Resources Information Center

    Hayes, Dianne

    2012-01-01

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

  6. Black Males Left Behind

    ERIC Educational Resources Information Center

    Mincy, Ronald B., Ed.

    2006-01-01

    Despite the overall economic gains in the 1990s, many young black men continue to have the poorest life chances of anyone in our society. Joblessness and low earnings among these less-educated young adults are contributing to reductions in marriage, increases in nonmarital childbearing, and a host of other social problems. In "Black Males…

  7. Constraining the last 7 billion years of galaxy evolution in semi-analytic models

    NASA Astrophysics Data System (ADS)

    Mutch, Simon J.; Poole, Gregory B.; Croton, Darren J.

    2013-01-01

    We investigate the ability of the Croton et al. semi-analytic model to reproduce the evolution of observed galaxies across the final 7 billion years of cosmic history. Using Monte Carlo Markov Chain techniques we explore the available parameter space to produce a model which attempts to achieve a statistically accurate fit to the observed stellar mass function at z = 0 and z ≈ 0.8, as well as the local black hole-bulge relation. We find that in order to be successful we are required to push supernova feedback efficiencies to extreme limits which are, in some cases, unjustified by current observations. This leads us to the conclusion that the current model may be incomplete. Using the posterior probability distributions provided by our fitting, as well as the qualitative details of our produced stellar mass functions, we suggest that any future model improvements must act to preferentially bolster star formation efficiency in the most massive haloes at high redshift.

  8. Salinity-related variation in gene expression in wild populations of the black-chinned tilapia from various West African coastal marine, estuarine and freshwater habitats

    NASA Astrophysics Data System (ADS)

    Tine, Mbaye; McKenzie, David J.; Bonhomme, François; Durand, Jean-Dominique

    2011-01-01

    This study measured the relative expression of the genes coding for Na +, K +-ATPase 1α(NAKA), voltage-dependent anion channel (VDAC), cytochrome c oxidase-1 (COX), and NADH dehydrogenase (NDH), in gills of six wild populations of a West African tilapia species, acclimatised to a range of seasonal (rainy or dry) salinities in coastal, estuarine and freshwater sites. Previous laboratory experiments have demonstrated that these genes, involved in active ion transport, oxidative phosphorylation, and intra-cellular ATP transport, are relatively over-expressed in gill tissues of this species acclimated to high salinity. Positive correlations between relative expression and ambient salinity were found for all genes in the wild populations (Spearman rank correlation, p < 0.05), although for some genes these were only significant in either the rainy season or dry season. Most significantly, however, relative expression was positively correlated amongst the four genes, indicating that they are functionally interrelated in adaptation of Sarotherodon melanotheron to salinity variations in its natural environment. In the rainy season, when salinity was unstable and ranged between zero and 37 psu across the sites, overall mean expression of the genes was higher than in the dry season, which may have reflected more variable particularly sudden fluctuations in salinity and poorer overall water quality. In the dry season, when the salinity is more stable but ranged between zero and 100 psu across the sites, NAKA, NDH and VDAC expression revealed U-shaped relationships with lowest relative expression at salinities approaching seawater, between 25 and 45 psu. Although it is not simple to establish direct relationship between gene expression levels and energy requirement for osmoregulation, these results may indicate that costs of adaptation to salinity are lowest in seawater, the natural environment of this species. While S. melanotheron can colonise environments with extremely

  9. Black holes and beyond

    SciTech Connect

    Mathur, Samir D.

    2012-11-15

    The black hole information paradox forces us into a strange situation: we must find a way to break the semiclassical approximation in a domain where no quantum gravity effects would normally be expected. Traditional quantizations of gravity do not exhibit any such breakdown, and this forces us into a difficult corner: either we must give up quantum mechanics or we must accept the existence of troublesome 'remnants'. In string theory, however, the fundamental quanta are extended objects, and it turns out that the bound states of such objects acquire a size that grows with the number of quanta in the bound state. The interior of the black hole gets completely altered to a 'fuzzball' structure, and information is able to escape in radiation from the hole. The semiclassical approximation can break at macroscopic scales due to the large entropy of the hole: the measure in the path integral competes with the classical action, instead of giving a subleading correction. Putting this picture of black hole microstates together with ideas about entangled states leads to a natural set of conjectures on many long-standing questions in gravity: the significance of Rindler and de Sitter entropies, the notion of black hole complementarity, and the fate of an observer falling into a black hole. - Highlights: Black-Right-Pointing-Pointer The information paradox is a serious problem. Black-Right-Pointing-Pointer To solve it we need to find 'hair' on black holes. Black-Right-Pointing-Pointer In string theory we find 'hair' by the fuzzball construction. Black-Right-Pointing-Pointer Fuzzballs help to resolve many other issues in gravity.

  10. Interior of a charged distorted black hole

    SciTech Connect

    Abdolrahimi, Shohreh; Frolov, Valeri P.; Shoom, Andrey A.

    2009-07-15

    We study the interior of a charged, nonrotating distorted black hole. We consider static and axisymmetric black holes, and focus on a special case when an electrically charged distorted solution is obtained by the Harrison-Ernst transformation from an uncharged one. We demonstrate that the Cauchy horizon of such a black hole remains regular, provided the distortion is regular at the event horizon. The shape and the inner geometry of both the outer and inner (Cauchy) horizons are studied. We demonstrate that there exists a duality between the properties of the horizons. Proper time of a free fall of a test particle moving in the interior of the distorted black hole along the symmetry axis is calculated. We also study the property of the curvature in the inner domain between the horizons. Simple relations between the 4D curvature invariants and the Gaussian curvature of the outer and inner horizon surfaces are found.

  11. Black hole evaporation rates without spacetime.

    PubMed

    Braunstein, Samuel L; Patra, Manas K

    2011-08-12

    Verlinde recently suggested that gravity, inertia, and even spacetime may be emergent properties of an underlying thermodynamic theory. This vision was motivated in part by Jacobson's 1995 surprise result that the Einstein equations of gravity follow from the thermodynamic properties of event horizons. Taking a first tentative step in such a program, we derive the evaporation rate (or radiation spectrum) from black hole event horizons in a spacetime-free manner. Our result relies on a Hilbert space description of black hole evaporation, symmetries therein which follow from the inherent high dimensionality of black holes, global conservation of the no-hair quantities, and the existence of Penrose processes. Our analysis is not wedded to standard general relativity and so should apply to extended gravity theories where we find that the black hole area must be replaced by some other property in any generalized area theorem.

  12. Primordial Black Holes from First Principles (Overview)

    NASA Astrophysics Data System (ADS)

    Lam, Casey; Bloomfield, Jolyon; Moss, Zander; Russell, Megan; Face, Stephen; Guth, Alan

    2017-01-01

    Given a power spectrum from inflation, our goal is to calculate, from first principles, the number density and mass spectrum of primordial black holes that form in the early universe. Previously, these have been calculated using the Press- Schechter formalism and some demonstrably dubious rules of thumb regarding predictions of black hole collapse. Instead, we use Monte Carlo integration methods to sample field configurations from a power spectrum combined with numerical relativity simulations to obtain a more accurate picture of primordial black hole formation. We demonstrate how this can be applied for both Gaussian perturbations and the more interesting (for primordial black holes) theory of hybrid inflation. One of the tools that we employ is a variant of the BBKS formalism for computing the statistics of density peaks in the early universe. We discuss the issue of overcounting due to subpeaks that can arise from this approach (the ``cloud-in-cloud'' problem). MIT UROP Office- Paul E. Gray (1954) Endowed Fund.

  13. Black Hole Observations - Towards the Event Horizon

    NASA Astrophysics Data System (ADS)

    Britzen, Silke

    Black Holes are probably the most elusive solutions of Einstein's theory of General Relativity. Despite numerous observations of the direct galactic environment and indirect influence of astrophysical black holes (e.g. jets, variable emission across the wavelength spectrum, feedback processes, etc.) -- a direct proof of their existence is still lacking. This article highlights some aspects deduced from many observations and concentrates on the experimental results with regard to black holes with masses from millions to billions of solar masses. The focus will be on the challenges and remaining questions. The Event Horizon Telescopce (EHT) project to image the photon sphere of Sgr A* and its potential is briefly sketched. This instrumental approach shall lead to highest resolution observations of the supermassive black hole at the center of the Milky Way (Sgr A*).

  14. Spatial Variation in the Storages and Age-Related Dynamics of Forest Carbon Sequestration in Different Climate Zones—Evidence from Black Locust Plantations on the Loess Plateau of China

    PubMed Central

    Li, Taijun; Ren, Bowen; Wang, Dahui; Liu, Guobin

    2015-01-01

    Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China’s Loess Plateau to assess the variation in C stocks and age-related dynamics. Our results demonstrated that black locust forests of the semi-humid zone stored significantly more C than did forests in the semi-arid zone, across the chronosequence (p < 0.001). The C carrying capacity of the plantations was measured at 166.4 Mg C ha−1 (1 Mg = 106 g) in the semi-humid zone, while the semi-arid zone had a capacity of only 79.4 Mg C ha−1. Soil organic C (SOC) increased continuously with stand age in the semi-arid zone (R2 = 0.84, p = 0.010). However, in the semi-humid zone, SOC declined sharply by 47.8% after the initial stage (5 to 10 y). The C stock in trees increased continuously with stand age in the semi-humid zone (R2 = 0.83, p = 0.011), yet in the semi-arid zone, it decreased dramatically from 43.0 Mg C ha−1 to 28.4 Mg C ha−1 during the old forest stage (38 to 56 y). The shift from being a net C sink to a net C source occurred at the initial stage in the semi-humid zone versus at the old forest stage in the semi-arid zone after reforestation. Surprisingly, with the exception of the initial and later stages (55 y), the patterns of C allocation among trees, soils, understory and litter were not statistically different between the two climate zones. Our results suggest that climate factors can alter the potential amount and age-related dynamics of forest C sequestration. PMID:25799100

  15. Spatial variation in the storages and age-related dynamics of forest carbon sequestration in different climate zones-evidence from black locust plantations on the Loess Plateau of China.

    PubMed

    Li, Taijun; Ren, Bowen; Wang, Dahui; Liu, Guobin

    2015-01-01

    Knowledge about the long-term influences of climate change on the amount of potential carbon (C) sequestration in forest ecosystems, including age-related dynamics, remains unclear. This study used two similar age-sequences of black locust forests (Robinia pseudoacacia L.) in the semi-arid and semi-humid zones of China's Loess Plateau to assess the variation in C stocks and age-related dynamics. Our results demonstrated that black locust forests of the semi-humid zone stored significantly more C than did forests in the semi-arid zone, across the chronosequence (p < 0.001). The C carrying capacity of the plantations was measured at 166.4 Mg C ha-1 (1 Mg = 106 g) in the semi-humid zone, while the semi-arid zone had a capacity of only 79.4 Mg C ha-1. Soil organic C (SOC) increased continuously with stand age in the semi-arid zone (R2 = 0.84, p = 0.010). However, in the semi-humid zone, SOC declined sharply by 47.8% after the initial stage (5 to 10 y). The C stock in trees increased continuously with stand age in the semi-humid zone (R2 = 0.83, p = 0.011), yet in the semi-arid zone, it decreased dramatically from 43.0 Mg C ha-1 to 28.4 Mg C ha-1 during the old forest stage (38 to 56 y). The shift from being a net C sink to a net C source occurred at the initial stage in the semi-humid zone versus at the old forest stage in the semi-arid zone after reforestation. Surprisingly, with the exception of the initial and later stages (55 y), the patterns of C allocation among trees, soils, understory and litter were not statistically different between the two climate zones. Our results suggest that climate factors can alter the potential amount and age-related dynamics of forest C sequestration.

  16. The genome of black raspberry (Rubus occidentalis).

    PubMed

    VanBuren, Robert; Bryant, Doug; Bushakra, Jill M; Vining, Kelly J; Edger, Patrick P; Rowley, Erik R; Priest, Henry D; Michael, Todd P; Lyons, Eric; Filichkin, Sergei A; Dossett, Michael; Finn, Chad E; Bassil, Nahla V; Mockler, Todd C

    2016-09-01

    Black raspberry (Rubus occidentalis) is an important specialty fruit crop in the US Pacific Northwest that can hybridize with the globally commercialized red raspberry (R. idaeus). Here we report a 243 Mb draft genome of black raspberry that will serve as a useful reference for the Rosaceae and Rubus fruit crops (raspberry, blackberry, and their hybrids). The black raspberry genome is largely collinear to the diploid woodland strawberry (Fragaria vesca) with a conserved karyotype and few notable structural rearrangements. Centromeric satellite repeats are widely dispersed across the black raspberry genome, in contrast to the tight association with the centromere observed in most plants. Among the 28 005 predicted protein-coding genes, we identified 290 very recent small-scale gene duplicates enriched for sugar metabolism, fruit development, and anthocyanin related genes which may be related to key agronomic traits during black raspberry domestication. This contrasts patterns of recent duplications in the wild woodland strawberry F. vesca, which show no patterns of enrichment, suggesting gene duplications contributed to domestication traits. Expression profiles from a fruit ripening series and roots exposed to Verticillium dahliae shed insight into fruit development and disease response, respectively. The resources presented here will expedite the development of improved black and red raspberry, blackberry and other Rubus cultivars.

  17. Black holes in magnetic monopoles

    NASA Technical Reports Server (NTRS)

    Lee, Kimyeong; Nair, V. P.; Weinberg, Erick J.

    1991-01-01

    We study magnetically charged classical solutions of a spontaneously broken gauge theory interacting with gravity. We show that nonsingular monopole solutions exist only if the Higgs field vacuum expectation value v is less than or equal to a critical value v sub cr, which is of the order of the Planck mass. In the limiting case, the monopole becomes a black hole, with the region outside the horizon described by the critical Reissner-Nordstrom solution. For v less than v sub cr, we find additional solutions which are singular at f = 0, but which have this singularity hidden within a horizon. These have nontrivial matter fields outside the horizon, and may be interpreted as small black holes lying within a magnetic monopole. The nature of these solutions as a function of v and of the total mass M and their relation to the Reissner-Nordstrom solutions is discussed.

  18. The next Black America: Obstacles amidst opportunities for Black families.

    PubMed

    Armah, Tichianaa

    2015-09-01

    In this article, the author offers personal accounts on how she feels about the current Black America and obstacles that people face reaching for opportunities for Black families. Focus relies on the current state of Black America, poverty, schools, academic achievement, raising children in the next Black America and much more. (PsycINFO Database Record

  19. Black Studies and Black People in the Future

    ERIC Educational Resources Information Center

    Stewart, James B.

    1976-01-01

    Suggests that the demise of Black Studies would foreshadow the future deterioration of the material conditions of black people, a situation which all elements of the black community want to preclude as a possible future for black people. (Author/AM)

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

    ERIC Educational Resources Information Center

    Stern, Mark; Hussain, Khuram

    2015-01-01

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

  1. Untapped Resources: "Styling" in Black Students' Writing for Black Audiences.

    ERIC Educational Resources Information Center

    Redd, Teresa M.

    Two studies compared the impact of black and white audiences on black students' writing style. In the first study, eight students in an all-black intermediate composition class completed one argumentative draft addressed to black opponents and one addressed to white opponents on two different topics. The essays were examined for stylistic features…

  2. ULTRAMASSIVE BLACK HOLE COALESCENCE

    SciTech Connect

    Khan, Fazeel Mahmood; Holley-Bockelmann, Kelly; Berczik, Peter E-mail: k.holley@vanderbilt.edu

    2015-01-10

    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.

  3. Wasting Time: Black Participation in the Combat Arms Branches

    DTIC Science & Technology

    2009-04-15

    you are a young black male or female you will find little in the way of strategic communications that will sway your decision to pursue an Army career...Corps and Army/Theater level Commands. None of the items mentioned above is readily available to the young Black male or female seeking informational...trends directly related to Minority Service in the combat arms branches of the United States Army. In other words the young black male or female

  4. Hairy Black Holes in Theories with Massive Gravitons

    NASA Astrophysics Data System (ADS)

    Volkov, Mikhail S.

    This is a brief survey of the known black hole solutions in the theories of ghost-free bigravity and massive gravity. Various black holes exist in these theories, in particular those supporting a massive graviton hair. However, it seems that solutions which could be astrophysically relevant are the same as in General Relativity, or very close to them. Therefore, the no-hair conjecture essentially applies, and so it would be hard to detect the graviton mass by observing black holes.

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

    NASA Astrophysics Data System (ADS)

    2003-09-01

    -energy particles have been detected around both types of black holes. Why do some stellar black holes spin rapidly and others not? One possibility is that differences in spin are imparted at birth when a massive star collapses. Another possibility is that the spin rate depends on how long the black hole has been devouring matter from its companion star, a process that makes the black hole spin faster. Black holes with more rapid spin, XTE J1650-500 and GX 339-4, have low-mass companion stars. These relatively long-lived stars may have been feeding the black hole for longer, allowing it to spin up to faster rates. Cygnus X-1 with its short-lived companion star may not have not time to spin up. Miller is a National Science Foundation Astronomy & Astrophysics Postdoctoral Fellow. His primary collaborators in this work were Walter Lewin if the Massachusetts Institute of Technology in Cambridge, Andrew Fabian of the University of Cambridge, UK, and Chris Reynolds of the University of Maryland, College Park. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the Office of Space Science, NASA Headquarters, Washington. Northrop Grumman of Redondo Beach, Calif., formerly TRW, Inc., was the prime development contractor for the observatory. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.

  6. Black Pete through the Eyes of Dutch Children

    PubMed Central

    Mesman, Judi; Janssen, Sofie; van Rosmalen, Lenny

    2016-01-01

    The traditional figure of Black Pete seen during the December festivities around Sinterklaas (the Dutch Santa Claus) in the Netherlands has sparked fierce debates about his racial stereotypical characteristics and his potentially negative effects on children’s opinions about black people. The Black Pete phenomenon has even been discussed by the United Nations Committee on the Elimination of Racial Discrimination, resulting in a report urging the Netherlands to eliminate this form of racial stereotyping. The adult debate about Black Pete is clearly important, but Sinterklaas is essentially a children’s holiday. Surprisingly, there have never been any systematic studies to examine children’s views on Black Pete. The current study is the first to do so. In a sample of 201 children aged 5–7 years, we collected free descriptions of Black Pete, asked children to group him in relation to other figures, and to assign characteristics to him and comparison figures. The results showed that (1) Children are clearly aware of Black Pete’s skin color and subordinate status; (2) Children associate Black Pete more with clowns than with black people; (3) Children evaluate Black Pete very positively, but the positive characteristics do not generalize to their evaluation of black people. The findings illustrate the deep-rooted childhood origins of many Dutch people’s affection for Black Pete and their lack of awareness of his relation to racial stereotypes. This explains the resistance to changing the Black Pete figure and the slowness of the change process on this front. PMID:27322583

  7. Measuring Black Hole Spin

    NASA Astrophysics Data System (ADS)

    Garmire, Gordon

    1999-09-01

    WE PROPOSE TO CARRY OUT A SYSTEMATIC STUDY OF EMISSION AND ABSORPTION SPECTRAL FEATURES THAT ARE OFTEN SEEN IN X-RAY SPECTRA OF BLACK HOLE BINARIES. THE EXCELLENT SENSITIVITY AND ENERGY RESOLUTION OF THE ACIS/HETG COMBINATION WILL NOT ONLY HELP RESOLVE AMBIGUITIES IN INTERPRETING THESE FEATURES, BUT MAY ALLOW MODELLING OF THE EMISSION LINE PROFILES IN DETAIL. THE PROFILES MAY CONTAIN INFORMATION ON SUCH FUNDAMENTAL PROPERTIES AS THE SPIN OF BLACK HOLES. THEREFORE, THIS STUDY COULD LEAD TO A MEASUREMENT OF BLACK HOLE SPIN FOR SELECTED SOURCES. THE RESULT CAN THEN BE DIRECTLY COMPARED WITH THOSE FROM PREVIOUS STUDIES BASED ON INDEPENDENT METHODS.

  8. The Price of "Black Dominance."

    ERIC Educational Resources Information Center

    Hoberman, John

    2000-01-01

    Discusses the harmful effects of stereotyping black males as athletes, noting that over-identification with athletes and the world of physical performance limits black children's development by discouraging academic achievement. Examines the negative influence of mass media focus on black athletes, rappers, and stylized ghetto blackness. Discusses…

  9. Black Writers' Views of America.

    ERIC Educational Resources Information Center

    Davis, Angela

    1979-01-01

    Contrary to their portrayal in "Black Macho and the Myth of the Superwoman," Black women were not passive in the Black liberation movement of the 1960s. Wallace does not acknowledge the organizing efforts of both Black men and women to challenge racism and sexism within the larger capitalist system. (Author/EB)

  10. Guide to the Black Novel.

    ERIC Educational Resources Information Center

    Lederer, Richard

    1969-01-01

    The nature of black literature raises questions about a black aesthetic and the universality of black expression. Central in the writings of Richard Wright and Ralph Ellison are the black man's confusion of identity, stemming from his invisibility in a white America, and the crimes of ignorance and blindness perpetrated on him by whites and by…

  11. Black Poverty: Past and Future.

    ERIC Educational Resources Information Center

    Smith, James P.

    The current debate over cutbacks in social programs for the black poor tends to overlook two fundamental realities. First, there has been a significant, long-term reduction in the number of black poor. Although black poverty remains at unacceptably high levels, a majority of blacks are now members of the middle class. Several factors have…

  12. Feminism and Black Women's Studies.

    ERIC Educational Resources Information Center

    Hooks, Bell

    1989-01-01

    Women's studies programs have largely ignored Black women. Until Black women's studies courses are developed, feminist scholarship on Black women will not advance, and the contributions of Black women to women's rights movements and African American literature and scholarship may be neglected. (DM)

  13. Soft Hair on Black Holes.

    PubMed

    Hawking, Stephen W; Perry, Malcolm J; Strominger, Andrew

    2016-06-10

    It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

  14. Soft Hair on Black Holes

    NASA Astrophysics Data System (ADS)

    Hawking, Stephen W.; Perry, Malcolm J.; Strominger, Andrew

    2016-06-01

    It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

  15. Constraints on black hole remnants

    SciTech Connect

    Giddings, S.B. )

    1994-01-15

    One possible fate of information lost to black holes is its preservation in black hole remnants. It is argued that a type of effective field theory describes such remnants (generically referred to as informons). The general structure of such a theory is investigated and the infinite pair production problem is revisited. A toy model for remnants clarifies some of the basic issues; in particular, infinite remnant production is not suppressed simply by the large internal volumes as proposed in cornucopion scenarios. Criteria for avoiding infinite production are stated in terms of couplings in the effective theory. Such instabilities remain a problem barring what would be described in that theory as a strong coupling conspiracy. The relation to Euclidean calculations of cornucopion production is sketched, and potential flaws in that analysis are outlined. However, it is quite plausible that pair production of ordinary black holes (e.g., Reissner-Noerdstrom or others) is suppressed due to strong effective couplings. It also remains an open possibility that a microsopic dynamics can be found yielding an appropriate strongly coupled effective theory of neutral informons without infinite pair production.

  16. Black Studies in Schools: A Review of Current Policies and Programs. Education U.S.A. Special Report.

    ERIC Educational Resources Information Center

    Levey, Rose Marie Walker

    This review, by the editors of "Education U.S.A.," surveys school systems across the country and lists outstanding programs relating to black studies in schools. Contents include: black studies--pros and cons; black studies and the schools--where do they stand?; black studies and the states--what have they done?; and, case studies of the fifteen…

  17. Black holes in full quantum gravity

    NASA Astrophysics Data System (ADS)

    Krasnov, Kirill; Rovelli, Carlo

    2009-12-01

    Quantum black holes have been studied extensively in quantum gravity and string theory, using various semiclassical or background-dependent approaches. We explore the possibility of studying black holes in the full non-perturbative quantum theory, without recurring to semiclassical considerations, and in the context of loop quantum gravity. We propose a definition of a quantum black hole as the collection of the quantum degrees of freedom that do not influence observables at infinity. From this definition, it follows that for an observer at infinity a black hole is described by an SU(2) intertwining operator. The dimension of the Hilbert space of such intertwiners grows exponentially with the horizon area. These considerations shed some light on the physical nature of the microstates contributing to the black hole entropy. In particular, it can be seen that the microstates being counted for the entropy have the interpretation of describing different horizon shapes. The space of black hole microstates described here is related to the one arrived at recently by Engle et al (2009, arXiv:0905.3168) and sometime ago by Smolin (1995, J. Math. Phys. 36 6417), but obtained here directly within the full quantum theory.

  18. Star formation around supermassive black holes.

    PubMed

    Bonnell, I A; Rice, W K M

    2008-08-22

    The presence of young massive stars orbiting on eccentric rings within a few tenths of a parsec of the supermassive black hole in the galactic center is challenging for theories of star formation. The high tidal shear from the black hole should tear apart the molecular clouds that form stars elsewhere in the Galaxy, and transport of stars to the galactic center also appears unlikely during their lifetimes. We conducted numerical simulations of the infall of a giant molecular cloud that interacts with the black hole. The transfer of energy during closest approach allows part of the cloud to become bound to the black hole, forming an eccentric disk that quickly fragments to form stars. Compressional heating due to the black hole raises the temperature of the gas up to several hundred to several thousand kelvin, ensuring that the fragmentation produces relatively high stellar masses. These stars retain the eccentricity of the disk and, for a sufficiently massive initial cloud, produce an extremely top-heavy distribution of stellar masses. This potentially repetitive process may explain the presence of multiple eccentric rings of young stars in the presence of a supermassive black hole.

  19. Binary Black Hole Mergers and Recoil Kicks

    NASA Technical Reports Server (NTRS)

    Centrella, Joan; Baker, J.; Choi, D.; Koppitz, M.; vanMeter, J.; Miller, C.

    2006-01-01

    Recent developments in numerical relativity have made it possible to follow reliably the coalescence of two black holes from near the innermost stable circular orbit to final ringdown. This opens up a wide variety of exciting astrophysical applications of these simulations. Chief among these is the net kick received when two unequal mass or spinning black holes merge. The magnitude of this kick has bearing on the production and growth of supermassive black holes during the epoch of structure formation, and on the retention of black holes in stellar clusters. Here we report the first accurate numerical calculation of this kick, for two nonspinning black holes in a 1.5:1 mass ratio, which is expected based on analytic considerations to give a significant fraction of the maximum possible recoil. We have performed multiple runs with different initial separations, orbital angular momenta, resolutions, extraction radii, and gauges. The full range of our kick speeds is 86-116 kilometers per second, and the most reliable runs give kicks between 86 and 97 kilometers per second. This is intermediate between the estimates from two recent post-Newtonian analyses and suggests that at redshifts z greater than 10, halos with masses less than 10(exp 9) M(sub SUN) will have difficulty retaining coalesced black holes after major mergers.

  20. Introducing the Black Hole

    ERIC Educational Resources Information Center

    Ruffini, Remo; Wheeler, John A.

    1971-01-01

    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)

  1. Black Hole Simulation

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This graphic shows the computer simulation of a black hole from start to finish. Plasma is falling slowly toward the black hole in a (at the upper left). The plasma has a magnetic field, shown by the white lines. It picks up speed as it falls toward the hole in b (at the upper right), c (lower left) and d (lower right). However, the rotating black hole twists up space itself (and the magnetic field lines) and ejects electromagnetic power along the north and south poles above the black hole. The red and white color shows the immense electromagnetic power output, which eventually will pick up particles and form squirting jets. This simulation was conducted using supercomputers at Japan's National Institute for Fusion Science.

  2. Janus black holes

    NASA Astrophysics Data System (ADS)

    Bak, Dongsu; Gutperle, Michael; Janik, Romuald A.

    2011-10-01

    In this paper Janus black holes in A dS 3 are considered. These are static solutions of an Einstein-scalar system with broken translation symmetry along the horizon. These solutions are dual to interface conformal field theories at finite temperature. An approximate solution is first constructed using perturbation theory around a planar BTZ blackhole. Numerical and exact solutions valid for all sets of parameters are then found and compared. Using the exact solution the thermodynamics of the system is analyzed. The entropy associated with the Janus black hole is calculated and it is found that the entropy of the black Janus is the sum of the undeformed black hole entropy and the entanglement entropy associated with the defect.

  3. Blacks in Appalachia

    ERIC Educational Resources Information Center

    Allen, Fayetta A.

    1974-01-01

    More than 1.3 million blacks live in Appalachian region reaching from Mississippi to New York State. Their existence and plight are ignored; they are colonized, exploited, and have few or no outlets for redress. (Author)

  4. Structure of Black Male Students Academic Achievement in Science

    NASA Astrophysics Data System (ADS)

    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.

  5. Socioeconomic factors affecting local support for black bear recovery strategies.

    PubMed

    Morzillo, Anita T; Mertig, Angela G; Hollister, Jeffrey W; Garner, Nathan; Liu, Jianguo

    2010-06-01

    There is global interest in recovering locally extirpated carnivore species. Successful efforts to recover Louisiana black bear in Louisiana have prompted interest in recovery throughout the species' historical range. We evaluated support for three potential black bear recovery strategies prior to public release of a black bear conservation and management plan for eastern Texas, United States. Data were collected from 1,006 residents living in proximity to potential recovery locations, particularly Big Thicket National Preserve. In addition to traditional logistic regression analysis, we used conditional probability analysis to statistically and visually evaluate probabilities of public support for potential black bear recovery strategies based on socioeconomic characteristics. Allowing black bears to repopulate the region on their own (i.e., without active reintroduction) was the recovery strategy with the greatest probability of acceptance. Recovery strategy acceptance was influenced by many socioeconomic factors. Older and long-time local residents were most likely to want to exclude black bears from the area. Concern about the problems that black bears may cause was the only variable significantly related to support or non-support across all strategies. Lack of personal knowledge about black bears was the most frequent reason for uncertainty about preferred strategy. In order to reduce local uncertainty about possible recovery strategies, we suggest that wildlife managers focus outreach efforts on providing local residents with general information about black bears, as well as information pertinent to minimizing the potential for human-black bear conflict.

  6. Socioeconomic Factors Affecting Local Support for Black Bear Recovery Strategies

    NASA Astrophysics Data System (ADS)

    Morzillo, Anita T.; Mertig, Angela G.; Hollister, Jeffrey W.; Garner, Nathan; Liu, Jianguo

    2010-06-01

    There is global interest in recovering locally extirpated carnivore species. Successful efforts to recover Louisiana black bear in Louisiana have prompted interest in recovery throughout the species’ historical range. We evaluated support for three potential black bear recovery strategies prior to public release of a black bear conservation and management plan for eastern Texas, United States. Data were collected from 1,006 residents living in proximity to potential recovery locations, particularly Big Thicket National Preserve. In addition to traditional logistic regression analysis, we used conditional probability analysis to statistically and visually evaluate probabilities of public support for potential black bear recovery strategies based on socioeconomic characteristics. Allowing black bears to repopulate the region on their own (i.e., without active reintroduction) was the recovery strategy with the greatest probability of acceptance. Recovery strategy acceptance was influenced by many socioeconomic factors. Older and long-time local residents were most likely to want to exclude black bears from the area. Concern about the problems that black bears may cause was the only variable significantly related to support or non-support across all strategies. Lack of personal knowledge about black bears was the most frequent reason for uncertainty about preferred strategy. In order to reduce local uncertainty about possible recovery strategies, we suggest that wildlife managers focus outreach efforts on providing local residents with general information about black bears, as well as information pertinent to minimizing the potential for human-black bear conflict.

  7. Big Black Holes Mean Bad News for Stars (diagram)

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] Poster Version Suppression of Star Formation from Supermassive Black Holes

    This diagram illustrates research from NASA's Galaxy Evolution Explorer showing that black holes -- once they reach a critical size -- can put the brakes on new star formation in elliptical galaxies.

    In this graph, galaxies and their supermassive black holes are indicated by the drawings (the black circle at the center of each galaxy represents the black hole). The relative masses of the galaxies and their black holes are reflected in the sizes of the drawings. Blue indicates that the galaxy has new stars, while red means the galaxy does not have any detectable new stars.

    The Galaxy Evolution Explorer observed the following trend: the biggest galaxies and black holes (shown in upper right corner) are more likely to have no observable star formation (red) than the smaller galaxies with smaller black holes. This is evidence that black holes can create environments unsuitable for stellar birth.

    The white line in the diagram illustrates that, for any galaxy no matter what the mass, its black hole must reach a critical size before it can shut down star formation.

  8. From the Tunnels into the Treetops: New Lineages of Black Yeasts from Biofilm in the Stockholm Metro System and Their Relatives among Ant-Associated Fungi in the Chaetothyriales

    PubMed Central

    Hubka, Vit; Thureborn, Olle; Lundberg, Johannes; Sallstedt, Therese; Wedin, Mats; Ivarsson, Magnus

    2016-01-01

    Rock-inhabiting fungi harbour species-rich, poorly differentiated, extremophilic taxa of polyphyletic origin. Their closest relatives are often well-known species from various biotopes with significant pathogenic potential. Speleothems represent a unique rock-dwelling habitat, whose mycobiota are largely unexplored. Isolation of fungi from speleothem biofilm covering bare granite walls in the Kungsträdgården metro station in Stockholm yielded axenic cultures of two distinct black yeast morphotypes. Phylogenetic analyses of DNA sequences from six nuclear loci, ITS, nuc18S and nuc28S rDNA, rpb1, rpb2 and β-tubulin, support their placement in the Chaetothyriales (Ascomycota). They are described as a new genus Bacillicladium with the type species B. lobatum, and a new species Bradymyces graniticola. Bacillicladium is distantly related to the known five chaetothyrialean families and is unique in the Chaetothyriales by variable morphology showing hyphal, meristematic and yeast-like growth in vitro. The nearest relatives of Bacillicladium are recruited among fungi isolated from cardboard-like construction material produced by arboricolous non-attine ants. Their sister relationship is weakly supported by the Maximum likelihood analysis, but strongly supported by Bayesian inference. The genus Bradymyces is placed amidst members of the Trichomeriaceae and is ecologically undefined; it includes an opportunistic animal pathogen while two other species inhabit rock surfaces. ITS rDNA sequences of three species accepted in Bradymyces and other undescribed species and environmental samples were subjected to phylogenetic analysis and in-depth comparative analysis of ITS1 and ITS2 secondary structures in order to study their intraspecific variability. Compensatory base change criterion in the ITS2 secondary structure supported delimitation of species in Bradymyces, which manifest a limited number of phenotypic features useful for species recognition. The role of fungi in the

  9. Seasonal dynamics of Trichodina spp. on whiting (Merlangius merlangus)in relation to organic pollution on the eastern Black Sea coast of Turkey.

    PubMed

    Ogut, Hamdi; Palm, Harry W

    2005-06-01

    It was determined that there is a relationship between prevalence and mean densities of Trichodina spp. on Merlangius merlangus and organic pollution, measured as levels of nitrite, nitrate and phosphate in the surrounding environment. Monthly, two left anterior gill arcs of 60 M. merlangus (unless otherwise stated) captured with hook and line were fixed in 10% formalin. The number of Trichodina spp. was determined by counting all of the cells with a grid slide. The two right anterior gill arcs were used to prepare dry smears to picture the morphology of the trichodinids and to determine species composition. High levels of prevalence and densities of the protozoan were observed during the late fall, winter and early spring months. Then, prevalence decreased to lower levels but never below 60%, an indication of the important role of M. merlangus for Trichodina spp. in the studied region. A multivariate analysis revealed that the magnitude of prevalence was related to the level of all three parameters: nitrite, nitrate and phosphate (r2=0.59). However, a much stronger relationship between prevalence and nitrate, phosphate, oxygen and temperature (r2=0.89) was detected. Consequently, the seasonal parasite prevalence and density were affected by organic pollution. The timing for a high prevalence and mean densities of this parasite also suggests that primary production may be responsible for the observed seasonal variation in prevalence and mean densities. By using the model describing the relationship between the water quality parameters and the prevalence data of Trichodina spp. recalculated values and observed field data corresponded closely.

  10. Numerical Relativity

    NASA Technical Reports Server (NTRS)

    Baker, John G.

    2009-01-01

    Recent advances in numerical relativity have fueled an explosion of progress in understanding the predictions of Einstein's theory of gravity, General Relativity, for the strong field dynamics, the gravitational radiation wave forms, and consequently the state of the remnant produced from the merger of compact binary objects. I will review recent results from the field, focusing on mergers of two black holes.

  11. Thermodynamics and luminosities of rainbow black holes

    SciTech Connect

    Mu, Benrong; Wang, Peng; Yang, Haitang E-mail: pengw@scu.edu.cn

    2015-11-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is ''Gravity's rainbow'', where the spacetime background felt by a test particle would depend on its energy. Focusing on the ''Amelino-Camelia dispersion relation'' which is E{sup 2} = m{sup 2}+p{sup 2}[1−η(E/m{sub p}){sup n}] with n > 0, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of η and n in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with η < 0 and n ≥ 2. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of η and n.

  12. Thermodynamics and luminosities of rainbow black holes

    NASA Astrophysics Data System (ADS)

    Mu, Benrong; Wang, Peng; Yang, Haitang

    2015-11-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is ``Gravity's rainbow'', where the spacetime background felt by a test particle would depend on its energy. Focusing on the ``Amelino-Camelia dispersion relation'' which is E2 = m2+p2[1-η(E/mp)n] with n > 0, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of η and n in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with η < 0 and n >= 2. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of η and n.

  13. Charged Galileon black holes

    SciTech Connect

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar E-mail: christos.charmousis@th.u-psud.fr

    2015-05-01

    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.

  14. Searching for Black Holes

    NASA Technical Reports Server (NTRS)

    Garcia, M.

    1998-01-01

    Our UV/VIS work concentrates on black hole X-ray nova. These objects consist of two stars in close orbit, one of which we believe is a black hole - our goal is to SHOW that one is a black hole. In order to reach this goal we carry out observations in the Optical, UV, IR and X-ray bands, and compare the observations to theoretical models. In the past year, our UV/VIS grant has provided partial support (mainly travel funds and page charges) for work we have done on X-ray nova containing black holes and neutron stars. We have been very successful in obtaining telescope time to support our project - we have completed approximately a dozen separate observing runs averaging 3 days each, using the MMT (5M), Lick 3M, KPNO 2.1M, CTIO 4M, CTIO 1.5M, and the SAO/WO 1.2M telescopes. These observations have allowed the identification of one new black hole (Nova Oph 1977), and allowed the mass of another to be measured (GS2000+25). Perhaps our most exciting new result is the evidence we have gathered for the existence of 'event horizons' in black hole X-ray nova.

  15. Modelling Gravitational Radiation from Binary Black Holes

    NASA Technical Reports Server (NTRS)

    Centrella, Joan

    2006-01-01

    The final merger and coalescence of binary black holes is a key source of strong gravitational waves for the LISA mission. Observing these systems will allow us to probe the formation of cosmic structure to high redshifts and test general relativity directly in the strong-field, dynamical regime. Recently, major breakthroughs have been made in modeling black hole mergers using numerical relativity. This talk will survey these exciting developments, focusing on the gravitational waveforms and the recoil kicks produced from non-equal mass mergers.

  16. Can Blacks Be Racists? Black-on-Black Principal Abuse in an Urban School Setting

    ERIC Educational Resources Information Center

    Khalifa, Muhammad

    2015-01-01

    This study examines Black student and parental perceptions of exclusionary practices of Black school principals. I ask why students and parents viewed two Black principals as contributing to abusive and exclusionary school environments that marginalized Black students. After a two-year ethnographic study, it was revealed that exclusionary…

  17. Asymptotically charged BTZ black holes in gravity's rainbow

    NASA Astrophysics Data System (ADS)

    Hendi, S. H.

    2016-04-01

    Motivated by the wide applications of BTZ black holes and interesting results of gravity's rainbow, we consider three dimensional rainbow solutions and investigate their thermodynamic properties. In addition to investigate black holes thermodynamics related to AdS/CFT correspondence, one may regard gravity's rainbow to encode quantum gravity effects into the black hole solutions. We take into account the various models of linear and nonlinear electrodynamics and study their effects on the gravity's rainbow spacetime. We also examine thermal stability and find that obtained three dimensional rainbow black holes are thermally stable.

  18. On the Møller Energy Associated with Black Holes

    NASA Astrophysics Data System (ADS)

    Saltı, Mustafa; Aydogdu, Oktay

    2006-12-01

    In this paper, we consider both Einstein's theory of general relativity and the teleparallel gravity (the tetrad theory of gravitation) analogs of the energy-momentum definition of Møller in order to explicitly evaluate the energy distribution (due to matter and fields including gravity) associated with a general black hole model which includes several well-known black holes. To calculate the special cases of energy distribution, here we consider eight different types of black hole models such as anti-de Sitter Cmetric with spherical topology, charged regular black hole, conformal scalar dyon black hole, dyadosphere of a charged black hole, regular black hole, charged topological black hole, charged massless black hole with a scalar field, and the Schwarzschild-de Sitter space-time. Our teleparallel gravitational result is also independent of the teleparallel dimensionless coupling constant, which means that it is valid not only in teleparallel equivalent of general relativity but also in any teleparallel model. This paper also sustains (a) the importance of the energy-momentum definitions in the evaluation of the energy distribution of a given spacetime and (b) the viewpoint of Lessner that the Møller energy-momentum complex is the powerful concept to calculate energy distribution in a given space-time.

  19. Learning about Black-Hole Formation from Gravitational Waves

    NASA Astrophysics Data System (ADS)

    Kesden, Michael H.

    2017-01-01

    The first observing run of the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) discovered gravitational waves from two binary black-hole mergers. Although astrophysical black holes are simple objects fully characterized by their masses and spins, key features of binary black-hole formation such as mass transfer, natal kicks, and common-envelope evolution can misalign black-hole spins with the orbital angular momentum of the binary. These misaligned spins will precess as gravitational-wave emission causes the black holes to inspiral to separations at which the waves are detectable by observatories like LIGO. Spin precession modulates the amplitude and frequency of the gravitational waves observed by LIGO, allowing it to not only test general relativity but also reveal the secrets of black-hole formation. This talk will briefly describe those elements of binary black-hole formation responsible for initial spin misalignments, how spin precession and radiation reaction in general relativity determine how spins evolve from formation until the black holes enter LIGO’s sensitivity band, and how spin-induced gravitational-wave modulation in band can be used as a diagnostic of black-hole formation.

  20. Black Sea Becomes Turquoise

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image shows bright, turquoise-colored swirls across the surface of the Black Sea, signifying the presence of a large phytoplankton bloom. Scientists have observed similar blooms recurring annually, roughly this same time of year. The Sea of Azov, which is the smaller body of water located just north of the Black Sea in this image, also shows a high level of color variance. The brownish pixels in the Azov are probably due to sediments carried in from high waters and snowmelt from upstream. This scene was acquired by the Moderate Resolution Imaging Spectroradiometer, flying aboard NASA's Terra satellite, on May 14, 2002. According to the Black Sea Environment Programme's Marine Hydrophysical Institute, the Black Sea is ?one of the marine areas of the world most damaged by human activities.? The coastal zone around these Eastern European inland water bodies is densely populated'supporting a permanent population of roughly 16 million people and another 4 million tourists each year. Six countries border with the Black Sea, including Ukraine to the north, Russia and Georgia to the east, Turkey to the south, and Bulgaria and Romania to the west. Because it is isolated from the world's oceans, and because there is an extensive drainage network of rivers that empty into it, the Black Sea has a unique and delicate water balance which is very important for supporting its marine ecosystem. Of particular concern to scientists is the salinity, water level, and nutrient levels of the Black Sea's waters, all of which are, unfortunately, being impacted by human activities. Within the last three decades the combination of increased nutrient loads from human sources together with pollution and over-harvesting of fisheries has resulted in a sharp decline in water quality. Scientists from each of the Black Sea's bordering nations are currently working together to study the issues and formulate a joint, international strategy for saving this unique marine ecosystem