Neighborhood Foreclosures, Racial/Ethnic Transitions, and Residential Segregation

PubMed Central

Hall, Matthew; Crowder, Kyle; Spring, Amy

2015-01-01

In this article, we use data on virtually all foreclosure events between 2005 and 2009 to calculate neighborhood foreclosure rates for nearly all block groups in the United States to assess the impact of housing foreclosures on neighborhood racial/ethnic change and on broader patterns of racial residential segregation. We find that the foreclosure crisis was patterned strongly along racial lines: black, Latino, and racially integrated neighborhoods had exceptionally high foreclosure rates. Multilevel models of racial/ethnic change reveal that foreclosure concentrations were linked to declining shares of whites and expanding shares of black and Latino residents. Results further suggest that these compositional shifts were driven by both white population loss and minority growth, especially from racially mixed settings with high foreclosure rates. To explore the impact of these racially selective migration streams on patterns of residential segregation, we simulate racial segregation assuming that foreclosure rates remained at their 2005 levels throughout the crisis period. Our simulations suggest that the foreclosure crisis increased racial segregation between blacks and whites by 1.1 dissimilarity points, and between Latinos and whites by 2.2 dissimilarity points. PMID:26120142

Drivers of precipitation change: An energetic understanding

NASA Astrophysics Data System (ADS)

Richardson, T.; Forster, P.; Andrews, T.

2016-12-01

Future precipitation changes are highly uncertain. Different drivers of anthropogenic climate change can cause very different hydrological responses, which could have significant societal implications. Changes in precipitation are tightly linked to the atmospheric energy budget due to the latent heat released through condensation. Through analysis of the atmospheric energy budget we make significant steps forward in understanding and predicting the precipitation response to different forcings. Here we analyse the response to five targeted forcing scenarios (perturbed CO2, CH4, black carbon, sulphate and solar insolation) across eight climate models participating in the Precipitation Driver and Response Model Intercomparison Project (PDRMIP). The resulting changes are split into a rapid adjustment component, due to the near-instantaneous changes in the atmospheric energy budget, and a feedback component which scales with surface temperature change. Globally, CO2 and black carbon produce large negative adjustments in precipitation due to the increase in atmospheric absorption. However, over land it is sulphate and solar forcing which produce the largest precipitation adjustments due to changes in horizontal energy transport associated with rapid circulation changes. Globally, the precipitation feedback response is very consistent between forcing scenarios, driven mainly by increased longwave cooling. The feedback response differs significantly over land and sea, with a larger feedback over the oceans. We use the PDRMIP results to construct a simple model for precipitation change over land and sea based on surface temperature change and top of the atmosphere forcing. The simple model matches well with CMIP5 ensemble mean precipitation change for RCP8.5. Simulated changes in land mean precipitation can be estimated well using the rapid adjustment and feedback framework, and understood through simple energy budget arguments. Up until present day the effects of temperature change on land mean precipitation have been entirely masked by sulphate forcing. However, as projected sulphate forcing decreases, and warming continues, the temperature driven increase in land mean precipitation soon dominates.

Supermassive black holes do not correlate with galaxy disks or pseudobulges.

PubMed

Kormendy, John; Bender, R; Cornell, M E

2011-01-20

The masses of supermassive black holes are known to correlate with the properties of the bulge components of their host galaxies. In contrast, they seem not to correlate with galaxy disks. Disk-grown 'pseudobulges' are intermediate in properties between bulges and disks; it has been unclear whether they do or do not correlate with black holes in the same way that bulges do. At stake in this issue are conclusions about which parts of galaxies coevolve with black holes, possibly by being regulated by energy feedback from black holes. Here we report pseudobulge classifications for galaxies with dynamically detected black holes and combine them with recent measurements of velocity dispersions in the biggest bulgeless galaxies. These data confirm that black holes do not correlate with disks and show that they correlate little or not at all with pseudobulges. We suggest that there are two different modes of black-hole feeding. Black holes in bulges grow rapidly to high masses when mergers drive gas infall that feeds quasar-like events. In contrast, small black holes in bulgeless galaxies and in galaxies with pseudobulges grow as low-level Seyfert galaxies. Growth of the former is driven by global processes, so the biggest black holes coevolve with bulges, but growth of the latter is driven locally and stochastically, and they do not coevolve with disks and pseudobulges.

Educational Differences in U.S. Adult Mortality: A Cohort Perspective*

PubMed Central

Masters, Ryan K.; Hummer, Robert A.; Powers, Daniel A.

2014-01-01

We use hierarchical cross-classified random-effects models to simultaneously measure age, period, and cohort patterns of mortality risk between 1986 and 2006 for non-Hispanic white and non-Hispanic black men and women with less than a high school education, a high school education, and more than a high school education. We examine all-cause mortality risk and mortality risk from heart disease, lung cancer, and unpreventable cancers. Findings reveal that temporal reductions in black and white men’s and women’s mortality rates were driven entirely by cohort changes in mortality. Findings also demonstrate that disparate cohort effects between education groups widened the education gap in all-cause mortality risk and mortality risk from heart disease and lung cancer across this time period. Educational disparities in mortality risk from unpreventable cancers, however, did not change. This research uncovers widening educational differences in adult mortality and demonstrates that a cohort perspective provides valuable insights for understanding recent temporal changes in U.S. mortality risk. PMID:25346542

The Merger-Free Growth of Galaxies and Supermassive Black Holes

NASA Astrophysics Data System (ADS)

Simmons, Brooke; Smethurst, Rebecca; Lintott, Chris; Martin, Garreth; Kaviraj, Sugata; Devriendt, Julien; Galaxy Zoo Team

2018-01-01

There is now clear evidence that the merger-driven pathway to black hole and galaxy growth is only half the story. Merger-free evolution contributes roughly equally to the overall growth of black holes in the Universe and is also responsible for a significant amount of galaxy growth over cosmic time. A recent study examining the growth of black holes in unambiguously disk-dominated galaxies shows these black holes reach quasar-like luminosities and black hole masses typical of those hosted in bulge-dominated and elliptical galaxies with major mergers in their evolutionary histories. However, while there appears to be no correlation between the size of the black hole and upper limits on the host galaxy bulges, the fitted correlation between black hole mass and total galaxy stellar mass in these merger-free systems is fully consistent with the canonical relationship based on merger-driven systems. There is further evidence via comparison between observed populations and cosmological simulations confirming that bulgeless systems are generally consistent with having merger-free histories. If bulgeless and disk-dominated galaxies are indeed signatures of systems with no violent mergers in their formation histories, the same correlation between black hole and galaxy in these systems versus that seen in elliptical galaxy samples indicates the black hole-galaxy connection must originate with a process more fundamental than the dynamical configuration of a galaxy's stars.

Still Flies in Buttermilk: Black Male Faculty, Critical Race Theory, and Composite Counterstorytelling

ERIC Educational Resources Information Center

Griffin, Rachel Alicia; Ward, LaCharles; Phillips, Amanda R.

2014-01-01

Driven by critical race theory, this essay employs composite counterstorytelling to narrate the experiences of black male faculty on traditionally white campuses. Situated at the intersections of race and gender, our composite counterstory is richly informed by 11 interviews with black male faculty alongside critical race scholarship that…

Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying

NASA Astrophysics Data System (ADS)

Richardson, T. B.; Forster, P. M.; Andrews, T.; Boucher, O.; Faluvegi, G.; Fläschner, D.; Kasoar, M.; Kirkevâg, A.; Lamarque, J.-F.; Myhre, G.; Olivié, D.; Samset, B. H.; Shawki, D.; Shindell, D.; Takemura, T.; Voulgarakis, A.

2018-03-01

Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.

Theory-driven intervention improves calcium intake, osteoporosis knowledge, and self-efficacy in community-dwelling older Black adults.

PubMed

Babatunde, Oyinlola T; Himburg, Susan P; Newman, Frederick L; Campa, Adriana; Dixon, Zisca

2011-01-01

To assess the effectiveness of an osteoporosis education program to improve calcium intake, knowledge, and self-efficacy in community-dwelling older Black adults. Randomized repeated measures experimental design. Churches and community-based organizations. Men and women (n = 110) 50 years old and older from 3 south Florida counties. Participants randomly assigned to either of 2 groups: Group 1 (experimental group) or Group 2 (wait-list control group). Group 1 participated in 6 weekly education program sessions immediately following baseline assessment, and Group 2 started the program following Group 1's program completion. A tested curriculum was adapted to meet the needs of the target population. Dietary calcium intake, osteoporosis knowledge, health beliefs, and self-efficacy. Descriptive and summary statistics, repeated measures analysis of variance, and regression analysis. Of the total participants, 84.6% completed the study (mean age = 70.2 years). Overall, an educational program developed with a theoretical background was associated with improvement in calcium intake, knowledge, and self-efficacy, with no effect on most health belief subscales. Assigned group was the major predictor of change in calcium intake. A theory-driven approach is valuable in improving behavior to promote bone health in this population. Health professionals should consider using more theory-driven approaches in intervention studies. Copyright © 2011 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

Black Sea outflow response to Holocene meltwater events.

PubMed

Herrle, Jens O; Bollmann, Jörg; Gebühr, Christina; Schulz, Hartmut; Sheward, Rosie M; Giesenberg, Annika

2018-03-06

During the Holocene, North American ice sheet collapse and rapid sea-level rise reconnected the Black Sea with the global ocean. Rapid meltwater releases into the North Atlantic and associated climate change arguably slowed the pace of Neolithisation across southeastern Europe, originally hypothesized as a catastrophic flooding that fueled culturally-widespread deluge myths. However, we currently lack an independent record linking the timing of meltwater events, sea-level rise and environmental change with the timing of Neolithisation in southeastern Europe. Here, we present a sea surface salinity record from the Northern Aegean Sea indicative of two meltwater events at ~8.4 and ~7.6 kiloyears that can be directly linked to rapid declines in the establishment of Neolithic sites in southeast Europe. The meltwater events point to an increased outflow of low salinity water from the Black Sea driven by rapid sea level rise >1.4 m following freshwater outbursts from Lake Agassiz and the final decay of the Laurentide ice sheet. Our results shed new light on the link between catastrophic sea-level rise and the Neolithisation of southeastern Europe, and present a historical example of how coastal populations could have been impacted by future rapid sea-level rise.

Trajectories of Ethnoracial Diversity in American Communities, 1980–2010*

PubMed Central

Hall, Matthew; Tach, Laura; Lee, Barrett A.

2017-01-01

The ethnoracial makeup of the U.S. population has undergone transformative change during recent decades, with the non-Hispanic white share of the population shrinking while the minority shares expand. Yet this trend toward greater racial diversity is not universal throughout the nation. Here we propose a framework of segmented change, which incorporates both spatial assimilation and ethnic stratification theories, to better understand variation in patterns of diversification across American communities. Our research applies growth mixture models to decennial census data on places for the 1980–2010 period, finding that trajectories of ethnoracial diversity are much more uneven than popularly claimed. Moreover, types of diversity change are stratified by initial racial composition. While places with mostly-white populations in 1980 underwent extensive diversification, places with larger shares of Hispanics and (especially) blacks in 1980 exhibited less uniform movement toward diversity and were more likely to remain racially homogeneous. Analysis of the underlying group-specific pathways of change indicates that the diversification of white communities was driven largely by Hispanic growth; when areas with a black presence did diversify, it occurred via contracting white populations. These racially conditioned and locally variable patterns emphasize the segmented nature of diversity change in American society. PMID:29398737

Spectral and Timing States in Black Hole Binaries

NASA Astrophysics Data System (ADS)

Wilms, J.

Results on the long term variability of galactic black hole candidates are reviewed. I mainly present the results of a > 2 year long campaign with RXTE to monitor the canonical soft state black hole candidates LMC X-1 and LMC X-3 using monthly observations. These observations are presented within the context of the RXTE-ASM long term quasi-periodic variability on timescales of about 150d. For LMC X-3, times of low ASM count rate are correlated with a significant hardening of the X-ray spectrum. The observation with the lowest flux during the whole monitoring campaign can be modeled with a simple γ=1.7 power law -- a hard state spectrum. Since these spectral hardenings occur on the 150 d timescale it is probable that they are associated with periodic changes in the accretion rate. Possible causes for this behavior are discussed, e.g. a wind driven limit-cycle or long-term variability of the donor star.

Identity and the Role of the State.

ERIC Educational Resources Information Center

Harvey, Luli

1997-01-01

Examples of marginalized nonformal learning in Britain that is driven by a search for alternative value systems include initiatives among Kurdish refugees, Blacks seeking identity through black studies, women sharing their stories, the resurgence of Irish culture, and the green movement. (SK)

The influence of environment, sex, and innate timing mechanisms on body temperature patterns of free-ranging black-tailed prairie dogs (Cynomys ludovicianus).

PubMed

Lehmer, Erin M; Bossenbroek, Jonathan M; Van Horne, Beatrice

2003-01-01

Mechanisms that influence body temperature patterns in black-tailed prairie dogs are not well understood. Previous research on both free-ranging and laboratory populations of black-tailed prairie dogs (Cynomys ludovicianus) has suggested that reductions in ambient temperature and food and water deprivation are the primary factors that stimulate torpor in this species. In other species, however, torpor has been shown to be influenced by a multitude of factors, including innate circadian and circannual timing mechanisms, energy status, and reproductive behaviors. Our objective was to clarify the influence of weather, sex, and intrinsic timing mechanisms on the body temperature patterns of free-ranging black-tailed prairie dogs. We monitored body temperatures of eight adult (>1 yr) prairie dogs from November 1999 to June 2000. Prairie dogs showed distinct daily and seasonal body temperature patterns, which reflected changes in ambient temperatures that occurred during these periods. These patterns of daily and seasonal heterothermy suggest that body temperature patterns of black-tailed prairie dogs may be driven by an innate timing mechanism. All prairie dogs entered torpor intermittently throughout winter and spring. Torpor bouts appeared to be influenced by precipitation and reductions in ambient temperature. Our results also suggest that reproductive behaviors and circadian timing may influence torpor in this species.

Post-Disaster Fertility: Hurricane Katrina and the Changing Racial Composition of New Orleans.

PubMed

Seltzer, Nathan; Nobles, Jenna

2017-06-01

Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences-beyond migration-driven population change-generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster's wake.

The Cenomanian-Turonian Oceanic Anoxic Event 2 (OAE2) in the Western Interior US and Gulf of Mexico: Decoupled Black Shale Deposition and Carbon Isotope Excursion

NASA Astrophysics Data System (ADS)

Lowery, C.; Snedden, J.; Cunningham, R.; Barrie, C.; Leckie, R. M.

2016-12-01

The largest carbon isotope excursions (CIEs) of the Cretaceous are associated with widespread evidence for marine anoxia and have been termed Oceanic Anoxic Events (OAEs). OAEs were originally thought to be globally-correlative intervals of black shales, but black shale deposition is an inherently provincial phenomenon driven by local conditions, and black shales associated with individual OAEs are often slightly diachronous and can be absent in some regions. Workers currently favor a definition of OAEs that is focused on the positive carbon isotope excursion driven by the global burial of organic matter and resulting carbon cycle perturbation; i.e., recording the global, rather than local, changes. While this is certainly the best way to define a global event, differences in the expression of the event between regions can be used to study the nature of the event itself. The greater Gulf of Mexico region in southern North America offers an excellent example of the diachroneity of black shale deposition and anoxia during one of the largest OAEs, the Cenomanian-Turonian OAE2. The Western Interior Seaway (WIS), flooded the interior of North America from the Gulf of Mexico up through the Canadian Arctic. In Texas and elsewhere across the WIS, high marine organic matter deposition and proxies for anoxia (especially benthic foraminifera and redox sensitive trace metals) are common before the event, but decrease at its onset, and in some places increase again after the event. Further south, across the Mexican shelf, deeper shelf environments remain dysoxic/anoxic through the event, while several carbonate platforms remain oxygenated during the event, but drown and record anoxic bottom waters shortly afterward. Here, we present new bulk carbonate and organic carbon isotopes and planktic and benthic foraminiferal populations from a 90 m core in southern Mississippi, USA, to present the first record of OAE2 from the northern Gulf of Mexico. In particular, we use foraminiferal populations to study the local redox conditions before, during, and after OAE2, and compare them to records from Mexico and across the WIS in order to understand regional patterns of environmental change, their underlying paleoclimatic and paleoceanographic drivers, and what this reveals about the overall development of OAE2.

Black shale deposition during Toarcian super-greenhouse driven by sea level

NASA Astrophysics Data System (ADS)

Hermoso, M.; Minoletti, F.; Pellenard, P.

2013-12-01

One of the most elusive aspects of the Toarcian oceanic anoxic event (T-OAE) is the paradox between carbon isotopes that indicate intense global primary productivity and organic carbon burial at a global scale, and the delayed expression of anoxia in Europe. During the earliest Toarcian, no black shales were deposited in the European epicontinental seaways, and most organic carbon enrichment of the sediments postdated the end of the overarching positive trend in the carbon isotopes that characterises the T-OAE. In the present study, we have attempted to establish a sequence stratigraphic framework for Early Toarcian deposits recovered from a core drilled in the Paris Basin using a combination of mineralogical (quartz and clay relative abundance) and geochemical (Si, Zr, Ti and Al) measurements. Combined with the evolution in redox sensitive elements (Fe, V and Mo), the data suggest that expression of anoxia was hampered in European epicontinental seas during most of the T-OAE (defined by the positive carbon isotope trend) due to insufficient water depth that prevented stratification of the water column. Only the first stratigraphic occurrence of black shales in Europe corresponds to the "global" event. This interval is characterised by >10% Total Organic Carbon (TOC) content that contains relatively low concentration of molybdenum compared to subsequent black shale horizons. Additionally, this first black shale occurrence is coeval with the record of the major negative Carbon Isotope Excursion (CIE), likely corresponding to a period of transient greenhouse intensification likely due to massive injection of carbon into the atmosphere-ocean system. As a response to enhanced weathering and riverine run-off, increased fresh water supply to the basin may have promoted the development of full anoxic conditions through haline stratification of the water column. In contrast, post T-OAE black shales during the serpentinum and bifrons Zones were restricted to epicontinental seas (higher Mo to TOC ratios) during a period of relative high sea level, and carbon isotopes returning to pre-T-OAE values. Comparing palaeoredox proxies with the inferred sequence stratigraphy for Sancerre suggests that episodes of short-term organic carbon enrichment were primarily driven by third-order sea level changes. These black shales exhibit remarkably well-expressed higher-frequency cyclicities in the oxygen availability in the water column whose nature has still to be determined through cyclostratigraphic analysis.

Black shale deposition during Toarcian super-greenhouse driven by sea level

NASA Astrophysics Data System (ADS)

Hermoso, M.; Minoletti, F.; Pellenard, P.

2013-07-01

One of the most elusive aspects of the Toarcian Oceanic Anoxic Event (T-OAE) is the paradox between carbon isotopes that indicate intense global primary productivity and organic carbon burial at a global scale, and the delayed expression of anoxia in Europe. During the earliest Toarcian, no black shales were deposited in the European epicontinental seaways, and most organic carbon enrichment of the sediments postdated the T-OAE (defined by the overarching positive trend in the carbon isotopes). In the present studied, we have attempted to establish a sequence stratigraphy framework for Early Toarcian deposits recovered from a core drilled in the Paris Basin using a combination of mineralogical (quartz and clay relative abundance) and geochemical (Si, Zr, Ti and Al) measurements. Combined with the evolution in redox sensitive elements (Fe, V and Mo), the data suggest that expression of anoxia was hampered in European epicontinental seas during most of the T-OAE due to insufficient water depth that prevented stratification of the water column. Only the first stratigraphic occurrence of black shales in Europe corresponds to the "global" event. This interval is characterised by > 10% Total Organic Carbon (TOC) content that contains relatively low concentration of molybdenum compared to subsequent black shale horizons. Additionally, this first black shale occurrence is coeval with the record of the major negative Carbon Isotope Excursion (CIE), likely corresponding to a period of transient greenhouse intensification likely due to massive injection of carbon into the Atmosphere-Ocean system. As a response to enhanced weathering and riverine run-off, increased fresh water supply to the basin may have promoted the development of full anoxic conditions through haline stratification of the water column. In contrast, post T-OAE black shales were restricted to epicontinental seas (higher Mo to TOC ratios) during a period of relative high sea level, and carbon isotopes returning to pre-T-OAE values. Comparing palaeoredox proxies with the inferred sequence stratigraphy for Sancerre suggests that episodes of short-term organic carbon enrichment were primarily driven by third-order sea level changes. These black shales exhibit remarkably well-expressed higher-frequency cyclicities in the concentration of redox-sensitive elements such as iron or vanadium whose nature has still to be determined through cyclostratigraphic analysis.

Hidden Homicide Increases in the USA, 1999–2005

PubMed Central

Hu, Guoqing; Webster, Daniel

2008-01-01

Prior to 1999, dramatic fluctuations in homicide rates were driven by changes in the rates of firearm homicide among men aged 15–24. Since 2000, the overall homicide rate has appeared stable, masking any changes in population subgroups. We analyzed recent trends in homicide rates by weapon, age, race, gender, state, and urbanization to determine whether the risk of victimization increased substantially during 1999–2005 for demographic subgroups. The analysis of WISQARS™ data and Wonder data from Centers for Disease Control and Prevention revealed no trend in the homicide rate nationally between 1999 and 2005; this obscured large increases in firearm homicide rates among black men aged 25–44 and among white men aged 25–34. Between 1999 and 2005, for ages 25–44 combined, the increase for black men was 31% compared with 12% for white men. Significant increases among men aged 25–44 occurred in Alabama, California, Michigan, Minnesota, Nebraska, Nevada, New Jersey, Ohio, Pennsylvania, Texas, and Washington. The firearm homicide rate increased the most in large central metropolitan areas (+32%) and large fringe metropolitan areas (+30%) for men aged 25–44. We conclude that the recent, unrecognized increases in firearm homicide among men aged 25–44, especially black men, in large metropolitan areas merit the attention of policymakers. PMID:18509760

Racial disparities in stage-specific colorectal cancer mortality rates from 1985 to 2008.

PubMed

Robbins, Anthony S; Siegel, Rebecca L; Jemal, Ahmedin

2012-02-01

Since the early 1980s, colorectal cancer (CRC) mortality rates for whites and blacks in the United States have been diverging as a result of earlier and larger reductions in death rates for whites. We examined whether this mortality pattern varies by stage at diagnosis. The Incidence-Based Mortality database of the Surveillance, Epidemiology, and End Results (SEER) Program was used to examine data from the nine original SEER regions. Our main outcome measures were changes in stage-specific mortality rates by race. From 1985 to 1987 to 2006 to 2008, CRC mortality rates decreased for each stage in both blacks and whites, but for every stage, the decreases were smaller for blacks, particularly for distant-stage disease. For localized stage, mortality rates decreased 30.3% in whites compared with 13.2% in blacks; for regional stage, declines were 48.5% in whites compared with 34.0% in blacks; and for distant stage, declines were 32.6% in whites compared with 4.6% in blacks. As a result, the black-white rate ratios increased from 1.17 (95% CI, 0.98 to 1.39) to 1.41 (95% CI, 1.21 to 1.63) for localized disease, from 1.03 (95% CI, 0.93 to 1.14) to 1.30 (95% CI, 1.17 to 1.44) for regional disease, and from 1.21 (95% CI, 1.10 to 1.34) to 1.72 (95% CI, 1.58 to 1.86) for distant-stage disease. In absolute terms, the disparity in distant-stage mortality rates accounted for approximately 60% of the overall black-white mortality disparity. The black-white disparities in CRC mortality increased for each stage of the disease, but the overall disparity in overall mortality was largely driven by trends for late-stage disease. Concerted efforts to prevent or detect CRC at earlier stages in blacks could improve the worsening black- white disparities.

Impacts of climate change on the formation and stability of late Quaternary sand sheets and falling dunes, Black Mesa region, southern Colorado Plateau, USA

USGS Publications Warehouse

Ellwein, Amy L.; Mahan, Shannon; McFadden, Leslie D.

2015-01-01

Widely used predictive models of eolian system dynamics are typically based entirely on climatic variables and do not account for landscape complexity and geomorphic history. Climate-only assumptions fail to give accurate predictions of the dynamics of this and many other dune fields. A growing body of work suggests that eolian deposits in wind-driven semiarid climates may be more strongly related to increases in sediment supply than to increases in aridity.

How to model AGN feedback in cosmological simulations?

NASA Astrophysics Data System (ADS)

Sijacki, Debora

2015-08-01

Hydrodynamical cosmological simulations are one of the most powerful tools to study the formation and evolution of galaxies in the fully non-linear regime. Despite several recent successes in simulating Milky Way look-alikes, self-consistent, ab-initio models are still a long way off. In this talk I will review numerical and physical uncertainties plaguing current state-of-the-art cosmological simulations of galaxy formation. I will then discuss which feedback mechanisms are needed to reproduce realistic stellar masses and galaxy morphologies in the present day Universe and argue that the black hole feedback is necessary for the quenching of massive galaxies. I will then demonstrate how black hole - host galaxy scaling relations depend on galaxy morphology and colour, highlighting the implications for the co-evolutionary picture between galaxies and their central black holes. In the second part of the talk I will present a novel method that permits to resolve gas flows around black holes all the way from large cosmological scales to the Bondi radii of black holes themselves. I will demonstrate that with this new numerical technique it is possible to estimate much more accurately gas properties in the vicinity of black holes than has been feasible before in galaxy and cosmological simulations, allowing to track reliably gas angular momentum transport from Mpc to pc scales. Finally, I will also discuss if AGN-driven outflows are more likely to be energy- or momentum-driven and what implications this has for the redshift evolution of black hole - host galaxy scaling relations.

Supported black phosphorus nanosheets as hydrogen-evolving photocatalyst achieving 5.4% energy conversion efficiency at 353 K.

PubMed

Tian, Bin; Tian, Bining; Smith, Bethany; Scott, M C; Hua, Ruinian; Lei, Qin; Tian, Yue

2018-04-11

Solar-driven water splitting using powdered catalysts is considered as the most economical means for hydrogen generation. However, four-electron-driven oxidation half-reaction showing slow kinetics, accompanying with insufficient light absorption and rapid carrier combination in photocatalysts leads to low solar-to-hydrogen energy conversion efficiency. Here, we report amorphous cobalt phosphide (Co-P)-supported black phosphorus nanosheets employed as photocatalysts can simultaneously address these issues. The nanosheets exhibit robust hydrogen evolution from pure water (pH = 6.8) without bias and hole scavengers, achieving an apparent quantum efficiency of 42.55% at 430 nm and energy conversion efficiency of over 5.4% at 353 K. This photocatalytic activity is attributed to extremely efficient utilization of solar energy (~75% of solar energy) by black phosphorus nanosheets and high-carrier separation efficiency by amorphous Co-P. The hybrid material design realizes efficient solar-to-chemical energy conversion in suspension, demonstrating the potential of black phosphorus-based materials as catalysts for solar hydrogen production.

Dual jets from binary black holes.

PubMed

Palenzuela, Carlos; Lehner, Luis; Liebling, Steven L

2010-08-20

The coalescence of supermassive black holes--a natural outcome when galaxies merge--should produce gravitational waves and would likely be associated with energetic electromagnetic events. We have studied the coalescence of such binary black holes within an external magnetic field produced by the expected circumbinary disk surrounding them. Solving the Einstein equations to describe black holes interacting with surrounding plasma, we present numerical evidence for possible jets driven by these systems. Extending the process described by Blandford and Znajek for a single, spinning black hole, the picture that emerges suggests that the electromagnetic field extracts energy from the orbiting black holes, which ultimately merge and settle into the standard Blandford-Znajek scenario. Emissions along these jets could potentially be observable at large distances.

Incidence and Progression of Chronic Kidney Disease in Black and White Individuals with Type 2 Diabetes.

PubMed

Gerber, Claire; Cai, Xuan; Lee, Jungwha; Craven, Timothy; Scialla, Julia; Souma, Nao; Srivastava, Anand; Mehta, Rupal; Paluch, Amanda; Hodakowski, Alexander; Frazier, Rebecca; Carnethon, Mercedes R; Wolf, Myles Selig; Isakova, Tamara

2018-06-07

Type 2 diabetes and associated CKD disproportionately affect blacks. It is uncertain if racial disparities in type 2 diabetes-associated CKD are driven by biologic factors that influence propensity to CKD or by differences in type 2 diabetes care. We conducted a post hoc analysis of 1937 black and 6372 white participants of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial to examine associations of black race with change in eGFR and risks of developing microalbuminuria, macroalbuminuria, incident CKD (eGFR<60 ml/min per 1.73m 2 , ≥25% decrease from baseline eGFR, and eGFR slope <-1.6 ml/min per 1.73 m 2 per year), and kidney failure or serum creatinine >3.3 mg/dl. During a median follow-up that ranged between 4.4 and 4.7 years, 278 black participants (58 per 1000 person-years) and 981 white participants (55 per 1000 person-years) developed microalbuminuria, 122 black participants (16 per 1000 person-years) and 374 white participants (14 per 1000 person-years) developed macroalbuminuria, 111 black participants (21 per 1000 person-years) and 499 white participants (28 per 1000 person-years) developed incident CKD, and 59 black participants (seven per 1000 person-years) and 178 white participants (six per 1000 person-years) developed kidney failure or serum creatinine >3.3 mg/dl. Compared with white participants, black participants had lower risks of incident CKD (hazard ratio, 0.73; 95% confidence intervals, 0.57 to 0.92). There were no significant differences by race in eGFR decline or in risks of microalbuminuria, macroalbuminuria, and kidney failure or of serum creatinine >3.3 mg/dl. Black participants enrolled in a randomized controlled trial had lower rates of incident CKD compared with white participants. Rates of eGFR decline, microalbuminuria, macroalbuminuria, and kidney failure did not vary by race. Copyright © 2018 by the American Society of Nephrology.

Effect of nuclear stars gravity on quasar radiation feedback on the parsec-scale

NASA Astrophysics Data System (ADS)

Yang, Xiao-Hong; Bu, De-Fu

2018-05-01

It is often suggested that a super massive black hole is embedded in a nuclear bulge of size of a few 102 parsec . The nuclear stars gravity is not negligible near ˜10parsec. In order to study the effect of nuclear stars gravity on quasar radiation feedback on the parsec scale, we have simulated the parsec scale flows irradiated by a quasar by taking into account the gravitational potential of both the black hole and the nuclear star cluster. We find that the effect of nuclear stars gravity on the parsec-scale flows is related to the fraction of X-ray photons in quasar radiation. For the models in which the fraction of X-ray photons is not small (e.g. the X-ray photons contribute to 20% of the quasar radiation), the nuclear stars gravity is very helpful to collimate the outflows driven by UV photons, significantly weakens the outflow power at the outer boundary and significantly enhances the net accretion rate onto the black hole. For the models in which X-ray photons are significantly decreased (e.g. the X-ray photons contribute to 5% of the quasar radiation), the nuclear stars gravity can just slightly change properties of outflow and slightly enhance the net accretion rate onto the black hole.

The effects of prospective mate quality on investments in healthy body weight among single women.

PubMed

Harris, Matthew C; Cronin, Christopher J

2017-02-01

This paper examines how a single female's investment in healthy body weight is affected by the quality of single males in her marriage market. A principle concern in estimation is the presence of market-level unobserved heterogeneity that may be correlated with changes in single male quality, measured as earning potential. To address this concern, we employ a differencing strategy that normalizes the exercise behaviors of single women to those of their married counterparts. Our main results suggest that when potential mate quality in a marriage market decreases, single black women invest less in healthy body weight. For example, we find that a 10 percentage point increase in the proportion of low quality single black males leads to a 5-10% decrease in vigorous exercise taken by single black females. Results for single white women are qualitatively similar, but not consistent across specifications. These results highlight the relationship between male and female human capital acquisition that is driven by participation in the marriage market. Our results suggest that programs designed to improve the economic prospects of single males may yield positive externalities in the form of improved health behaviors, such as more exercise, particularly for single black females. Copyright © 2016 Elsevier B.V. All rights reserved.

Endotoxemia and the host systemic response during experimental gingivitis.

PubMed

Wahaidi, Vivian Y; Kowolik, Michael J; Eckert, George J; Galli, Dominique M

2011-05-01

To assess endotoxemia episodes and subsequent changes in serum inflammatory biomarkers using the experimental gingivitis model. Data from 50 healthy black and white adult males and females were compared for serum concentrations of endotoxin, and serum biomarkers [neutrophil oxidative activity, interleukin (IL)-1β, IL-6, IL-8, C-reactive protein (CRP), and fibrinogen] at baseline, at 3 weeks of experimental gingivitis, and after 2 weeks of recovery. Means were compared using repeated measures analysis of variance. Endotoxemia was reported in 56% of the serum samples at 3 weeks of induced gingivitis. At 2 weeks of recovery, endotoxin levels decreased to levels similar to those reported at baseline. Neutrophil oxidative activity increased significantly following 3 weeks of gingivitis versus baseline (p<0.05). In the endotoxin-negative group this increase was associated with the black subjects whereas in the endotoxin-positive group change in neutrophil activity was driven by the female subpopulation. Serum cytokines, CRP, and fibrinogen levels did not change during the study. Experimental gingivitis was associated with endotoxemia and hyperactivity of circulating neutrophils, but not with changes in systemic levels of cytokines and acute-phase proteins. This may be attributed to the mild nature and the short duration of the induced gingivitis. © 2011 John Wiley & Sons A/S.

Endotoxemia and the host systemic response during experimental gingivitis

PubMed Central

Wahaidi, Vivian Y.; Kowolik, Michael J.; Eckert, George J.; Galli, Dominique M.

2011-01-01

Aim To assess endotoxemia episodes and subsequent changes in serum inflammatory biomarkers using the experimental gingivitis model Materials and Methods Data from 50 healthy black and white adult males and females were compared for serum concentrations of endotoxin, and serum biomarkers [neutrophil oxidative activity, interleukin (IL)-1β, IL-6, IL-8, C-reactive protein, and fibrinogen] at baseline, at 3 weeks of experimental gingivitis, and after 2 weeks of recovery. Means were compared using repeated measures ANOVA. Results Endotoxemia was reported in 56% of the serum samples at three weeks of induced gingivitis. At two weeks of recovery, endotoxin levels decreased to levels similar to those reported at baseline. Neutrophil oxidative activity increased significantly following three weeks of gingivitis versus baseline (p<0.05). In the endotoxin-negative group this increase was associated with the black subjects whereas in the endotoxin-positive group change in neutrophil activity was driven by the female subpopulation. Serum cytokines, CRP, and fibrinogen levels did not change during the study. Conclusions Experimental gingivitis was associated with endotoxemia and hyperactivity of circulating neutrophils, but not with changes in systemic levels of cytokines and acute phase proteins. This may be attributed to the mild nature and the short duration of the induced gingivitis. PMID:21320151

Weak Hydrological Sensitivity to Temperature Change over Land, Independent of Climate Forcing

NASA Technical Reports Server (NTRS)

Samset, B. H.; Myhre, G.; Forster, P. M.; Hodnebrog, O.; Andrews, T.; Boucher, O.; Faluvegi, G.; Flaeschner, D.; Kasoar, M.; Kharin, V.;

Multiple strategies to identify HIV-positive black men who have sex with men and transgender women in New York City: a cross-sectional analysis of recruitment results.

PubMed

Franks, Julie; Mannheimer, Sharon B; Hirsch-Moverman, Yael; Hayes-Larson, Eleanor; Colson, Paul W; Ortega, Hugo; El-Sadr, Wafaa M

2018-03-01

Black men who have sex with men and transgender women are at high risk for HIV infection, but are more likely to be unaware of their infection or not in care for diagnosed HIV compared to other races. Respondent driven sampling has been advanced as a method to reach stigmatized and hidden populations for HIV testing. We compared strategies to recruit black, substance-using men who have sex with men and transgender women to identify newly diagnosed HIV infection, or those previously diagnosed but not in care. The STAR (Seek, Test, and Retain) study (ClinicalTrials.gov NCT01790360) used several recruitment strategies to identify black, substance-using men who have sex with men and transgender women with undiagnosed HIV infection or with previously diagnosed HIV infection but who were not in HIV care. Respondent-driven sampling, community-based recruitment and online advertising were used to recruit participants. Incentivized peer referral was integrated into all recruitment strategies. Participants completed interviewer-administered questionnaires and HIV testing. Demographic and HIV risk-related characteristics and recruitment strategy were summarized and stratified by HIV status. Associations were tested using Pearson's chi-squared, Fisher's exact, and Wilcoxon rank sum tests. Factors associated with HIV-positive diagnosis at p < 0.1 were included in a multivariable logistic regression model. From July 2012 through October 2015, the study enrolled 1929 participants; 96.3% men who have sex with men and 3.7% transgender women. Behavioural risk factors included recent condomless anal sex (55.6%) and recent substance use during sex (73.1%). HIV prevalence was 8.7%. In multivariable analysis, significant associations with HIV infection included being transgender; non-Hispanic black; gay/homosexual orientation; not homeless; and less likely to have insufficient income for necessities. Among recruitment strategies, respondent driven sampling was least effective in identifying HIV-positive participants. Integrating multiple recruitment strategies yielded a large sample of black men who have sex with men and transgender women at substantial risk for HIV. Respondent-driven sampling was less effective than other strategies at identifying men who have sex with men and transgender women with HIV. © 2018 The Authors. Journal of the International AIDS Society published by John Wiley & sons Ltd on behalf of the International AIDS Society.

Can Black Hole Relax Unitarily?

NASA Astrophysics Data System (ADS)

Solodukhin, S. N.

2005-03-01

We review the way the BTZ black hole relaxes back to thermal equilibrium after a small perturbation and how it is seen in the boundary (finite volume) CFT. The unitarity requires the relaxation to be quasi-periodic. It is preserved in the CFT but is not obvious in the case of the semiclassical black hole the relaxation of which is driven by complex quasi-normal modes. We discuss two ways of modifying the semiclassical black hole geometry to maintain unitarity: the (fractal) brick wall and the worm-hole modification. In the latter case the entropy comes out correctly as well.

Chemical potential driven phase transition of black holes in anti-de Sitter space

NASA Astrophysics Data System (ADS)

Galante, Mario; Giribet, Gaston; Goya, Andrés; Oliva, Julio

2015-11-01

Einstein-Maxwell theory conformally coupled to a scalar field in D dimensions may exhibit a phase transition at low temperature whose end point is an asymptotically anti-de Sitter black hole with a scalar field profile that is regular everywhere outside and on the horizon. This provides a tractable model to study the phase transition of hairy black holes in anti-de Sitter space in which the backreaction on the geometry can be solved analytically.

Theory-Driven Intervention Improves Calcium Intake, Osteoporosis Knowledge, and Self-Efficacy in Community-Dwelling Older Black Adults

ERIC Educational Resources Information Center

Babatunde, Oyinlola T.; Himburg, Susan P.; Newman, Frederick L.; Campa, Adriana; Dixon, Zisca

2011-01-01

Objective: To assess the effectiveness of an osteoporosis education program to improve calcium intake, knowledge, and self-efficacy in community-dwelling older Black adults. Design: Randomized repeated measures experimental design. Setting: Churches and community-based organizations. Participants: Men and women (n = 110) 50 years old and older…

Sulfide-driven arsenic mobilization from arsenopyrite and black shale pyrite

USGS Publications Warehouse

Zhu, W.; Young, L.Y.; Yee, N.; Serfes, M.; Rhine, E.D.; Reinfelder, J.R.

2008-01-01

We examined the hypothesis that sulfide drives arsenic mobilization from pyritic black shale by a sulfide-arsenide exchange and oxidation reaction in which sulfide replaces arsenic in arsenopyrite forming pyrite, and arsenide (As-1) is concurrently oxidized to soluble arsenite (As+3). This hypothesis was tested in a series of sulfide-arsenide exchange experiments with arsenopyrite (FeAsS), homogenized black shale from the Newark Basin (Lockatong formation), and pyrite isolated from Newark Basin black shale incubated under oxic (21% O2), hypoxic (2% O2, 98% N2), and anoxic (5% H2, 95% N2) conditions. The oxidation state of arsenic in Newark Basin black shale pyrite was determined using X-ray absorption-near edge structure spectroscopy (XANES). Incubation results show that sulfide (1 mM initial concentration) increases arsenic mobilization to the dissolved phase from all three solids under oxic and hypoxic, but not anoxic conditions. Indeed under oxic and hypoxic conditions, the presence of sulfide resulted in the mobilization in 48 h of 13-16 times more arsenic from arsenopyrite and 6-11 times more arsenic from isolated black shale pyrite than in sulfide-free controls. XANES results show that arsenic in Newark Basin black shale pyrite has the same oxidation state as that in FeAsS (-1) and thus extend the sulfide-arsenide exchange mechanism of arsenic mobilization to sedimentary rock, black shale pyrite. Biologically active incubations of whole black shale and its resident microorganisms under sulfate reducing conditions resulted in sevenfold higher mobilization of soluble arsenic than sterile controls. Taken together, our results indicate that sulfide-driven arsenic mobilization would be most important under conditions of redox disequilibrium, such as when sulfate-reducing bacteria release sulfide into oxic groundwater, and that microbial sulfide production is expected to enhance arsenic mobilization in sedimentary rock aquifers with major pyrite-bearing, black shale formations. ?? 2008 Elsevier Ltd. All rights reserved.

Man made deltas?

NASA Astrophysics Data System (ADS)

Maselli, V.; Trincardi, F.

2014-12-01

During the last few millennia, southern European fluvio-deltaic systems have evolved in response to changes in the hydrological cycle, mostly driven by high-frequency climate oscillations and increasing anthropic pressure on natural landscapes. The review of geochronological and historical data documents that the bulk of the four largest northern Mediterranean and Black Sea deltas (Ebro, Rhone, Po and Danube) formed during two short and synchronous intervals during which anthropogenic land cover change was the main driver for enhanced sediment production. These two major growth phases occurred under contrasting climatic regimes and were both followed by generalized delta retreat, supporting the hypothesis of human-driven delta progradation. Delta retreat, in particular, was the consequence of reduced soil erosion for renewed afforestation after the fall of the Roman Empire, and of river dams construction that overkilled the still increasing sediment production in catchment basins since the Industrial Era. In this second case, in particular, the effect of a reduced sediment flux to the coasts is amplified by the sinking of modern deltas, due to land subsidence and sea level rise, that hampers delta outbuilding and increases the vulnerability of coastal zone to marine erosion and flooding.

Urban Preparation: Young Black Men Moving from Chicago's South Side to Success in Higher Education

ERIC Educational Resources Information Center

Warren, Chezare A.

2017-01-01

Chezare A. Warren chronicles the transition of a cohort of young Black males from Urban Prep Charter Academy for Young Men to their early experiences in higher education. A rich and closely observed account of a mission-driven school and its students, "Urban Preparation" makes a significant contribution to our understanding of how young…

INTRINSIC ELECTROMAGNETIC VARIABILITY IN CELESTIAL OBJECTS CONTAINING RAPIDLY SPINNING BLACK HOLES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Fan, E-mail: fnzhang@bnu.edu.cn; Department of Physics and Astronomy, West Virginia University, P.O. Box 6315, Morgantown, WV 26506

2016-02-10

Analytical studies have raised the concern that a mysterious expulsion of magnetic field lines by a rapidly spinning black hole (dubbed the black hole Meissner effect) would shut down the Blandford–Znajek process and quench the jets of active galactic nuclei and microquasars. This effect is, however, not seen observationally or in numerical simulations. Previous attempts at reconciling the predictions with observations have proposed several mechanisms to evade the Meissner effect. In this paper, we identify a new evasion mechanism and discuss its observational significance. Specifically, we show that the breakdown of stationarity is sufficient to remove the expulsion of themore » magnetic field at all multipole orders, and that the associated temporal variation is likely turbulent because of the existence of efficient mechanisms for sharing energy across different modes. Such an intrinsic (as opposed to being driven externally by, e.g., changes in the accretion rate) variability of the electromagnetic field can produce the recorded linear correlation between microvariability amplitudes and mean fluxes, help create magnetic randomness and seed sheared magnetic loops in jets, and lead to a better theoretical fit to the X-ray microvariability power spectral density.« less

Intrinsic Electromagnetic Variability in Celestial Objects Containing Rapidly Spinning Black Holes

NASA Astrophysics Data System (ADS)

Zhang, Fan

2016-02-01

Analytical studies have raised the concern that a mysterious expulsion of magnetic field lines by a rapidly spinning black hole (dubbed the black hole Meissner effect) would shut down the Blandford-Znajek process and quench the jets of active galactic nuclei and microquasars. This effect is, however, not seen observationally or in numerical simulations. Previous attempts at reconciling the predictions with observations have proposed several mechanisms to evade the Meissner effect. In this paper, we identify a new evasion mechanism and discuss its observational significance. Specifically, we show that the breakdown of stationarity is sufficient to remove the expulsion of the magnetic field at all multipole orders, and that the associated temporal variation is likely turbulent because of the existence of efficient mechanisms for sharing energy across different modes. Such an intrinsic (as opposed to being driven externally by, e.g., changes in the accretion rate) variability of the electromagnetic field can produce the recorded linear correlation between microvariability amplitudes and mean fluxes, help create magnetic randomness and seed sheared magnetic loops in jets, and lead to a better theoretical fit to the X-ray microvariability power spectral density.

Black hole shadow in an expanding universe with a cosmological constant

NASA Astrophysics Data System (ADS)

Perlick, Volker; Tsupko, Oleg Yu.; Bisnovatyi-Kogan, Gennady S.

2018-05-01

We analytically investigate the influence of a cosmic expansion on the shadow of the Schwarzschild black hole. We suppose that the expansion is driven by a cosmological constant only and use the Kottler (or Schwarzschild-de Sitter) spacetime as a model for a Schwarzschild black hole embedded in a de Sitter universe. We calculate the angular radius of the shadow for an observer who is comoving with the cosmic expansion. It is found that the angular radius of the shadow shrinks to a nonzero finite value if the comoving observer approaches infinity.

Dosing of selective serotonin reuptake inhibitors in children and adults before and after the FDA black-box warning

PubMed Central

Bushnell, Greta A; Stürmer, Til; Swanson, Sonja A; White, Alice; Azrael, Deborah; Pate, Virginia; Miller, Matthew

2016-01-01

Objective Prior research evaluated various effects of the antidepressant black-box warning on the risk of suicidality in children, but the dosing of antidepressants has not been considered. This study estimated, relative to the FDA warnings, whether the initial antidepressant dose prescribed decreased and the proportion augmenting dose on the second fill increased. Method The study utilized the LifeLink Health Plan Claims Database. The study cohort consisted of commercially insured children (5–17 years), young adults (18–24 years), and adults (25–64 years) initiating an SSRI (citalopram, fluoxetine, paroxetine, or sertraline) from 1/1/2000 to 12/31/2009. Dose-per-day was determined by days supply, strength, and quantity dispensed. Initiation on low dose, defined based on guidelines, and dose augmentations (dose increase >1mg/day) on the second prescription were considered across time periods related to the antidepressant warnings. Results Of 51,948 children who initiated an SSRI, 15% initiated on low dose in the period before the 2004 black-box warning and 31% in the period after the warning (a 16 percentage-point change); there was a smaller percentage-point change in young adults (6%) and adults (3%). The overall increase in dose augmentations in children and young adults was driven by the increase in patients initiating on a low dose. Conclusions As guidelines recommend children initiate antidepressant treatment on low dose, findings that an increased proportion of commercially insured children initiated an SSRI on low dose after the 2004 black-box warning suggest prescribing practices surrounding SSRI dosing improved in children following the warning but dosing practices still fall short of guidelines. PMID:26567938

Post-merger evolution of a neutron star-black hole binary with neutrino transport

NASA Astrophysics Data System (ADS)

Foucart, Francois; O'Connor, Evan; Roberts, Luke; Duez, Matthew D.; Haas, Roland; Kidder, Lawrence E.; Ott, Christian D.; Pfeiffer, Harald P.; Scheel, Mark A.; Szilagyi, Bela

2015-06-01

We present a first simulation of the post-merger evolution of a black hole-neutron star binary in full general relativity using an energy-integrated general-relativistic truncated moment formalism for neutrino transport. We describe our implementation of the moment formalism and important tests of our code, before studying the formation phase of an accretion disk after a black hole-neutron star merger. We use as initial data an existing general-relativistic simulation of the merger of a neutron star of mass 1.4 M⊙ with a black hole of mass 7 M⊙ and dimensionless spin χBH=0.8 . Comparing with a simpler leakage scheme for the treatment of the neutrinos, we find noticeable differences in the neutron-to-proton ratio in and around the disk, and in the neutrino luminosity. We find that the electron neutrino luminosity is much lower in the transport simulations, and that both the disk and the disk outflows are less neutron rich. The spatial distribution of the neutrinos is significantly affected by relativistic effects, due to large velocities and curvature in the regions of strongest emission. Over the short time scale evolved, we do not observe purely neutrino-driven outflows. However, a small amount of material (3 ×10-4M⊙ ) is ejected in the polar region during the circularization of the disk. Most of that material is ejected early in the formation of the disk, and is fairly neutron rich (electron fraction Ye˜0.15 - 0.25 ). Through r-process nucleosynthesis, that material should produce high-opacity lanthanides in the polar region, and could thus affect the light curve of radioactively powered electromagnetic transients. We also show that by the end of the simulation, while the bulk of the disk remains neutron rich (Ye˜0.15 - 0.2 and decreasing), its outer layers have a higher electron fraction: 10% of the remaining mass has Ye>0.3 . As that material would be the first to be unbound by disk outflows on longer time scales, and as composition evolution is slower at later times, the changes in Ye experienced during the formation phase of the disk could have an impact on nucleosynthesis outputs from neutrino-driven and viscously driven outflows. Finally, we find that the effective viscosity due to momentum transport by neutrinos is unlikely to have a strong effect on the growth of the magnetorotational instability in the post-merger accretion disk.

Sacrificial Protective Coating Materials that can be Regenerated In-Situ to Enable High Performance Membranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malati, Peter; Ganguli, Rahul; Mehrotra, Vivek

In the pulp and paper industry, weak black liquor concentration is carried out using energy intensive evaporators. Briefly, after wood digestion, water is evaporated to concentrate weak black liquor to the point where the black liquor can be burned in a recovery boiler, which ultimately leads to the recovery of digestion chemicals. Because it is less energy intensive than heat-driven separation, pressure-driven separation of water from black liquor using membranes could reduce the energy usage by 55 trillion Btu yr -1 and carbon dioxide emissions by more than 11 million metric tons CO 2 per year if the first twomore » evaporators are replaced. However, weak black liquor is a hot, corrosive, and highly fouling feed with organic molecules, colloids, and ions that clog membranes within hours of operation. We have shown that membrane-based concentration of weak black liquor is feasible, but only with our antifouling and anti-clogging technology that is based on a sacrificial Bio-inspired Living Skin concept. This concept is based on a conformal coating that is formed at the membrane surface and within the pores. Weak foulant adhesion dramatically decreases membrane fouling while the superhydrophilicity of the coating increases the water permeability. Moreover, the coating can be completely removed during backflushing, which removes foulants that may irreversibly adhere to the coating over long periods of time. The skin shedding completely regenerates the membrane surface and pores, restoring the original flux. This is followed by in-situ recoating, using the existing membrane plumbing and pumps, which essentially creates a brand new membrane surface.« less

Projections of white and black older adults without living kin in the United States, 2015 to 2060.

PubMed

Verdery, Ashton M; Margolis, Rachel

2017-10-17

Close kin provide many important functions as adults age, affecting health, financial well-being, and happiness. Those without kin report higher rates of loneliness and experience elevated risks of chronic illness and nursing facility placement. Historical racial differences and recent shifts in core demographic rates suggest that white and black older adults in the United States may have unequal availability of close kin and that this gap in availability will widen in the coming decades. Whereas prior work explores the changing composition and size of the childless population or those without spouses, here we consider the kinless population of older adults with no living close family members and how this burden is changing for different race and sex groups. Using demographic microsimulation and the United States Census Bureau's recent national projections of core demographic rates by race, we examine two definitions of kinlessness: those without a partner or living children, and those without a partner, children, siblings, or parents. Our results suggest dramatic growth in the size of the kinless population as well as increasing racial disparities in percentages kinless. These conclusions are driven by declines in marriage and are robust to different assumptions about the future trajectory of divorce rates or growth in nonmarital partnerships. Our findings draw attention to the potential expansion of older adult loneliness, which is increasingly considered a threat to population health, and the unequal burden kinlessness may place on black Americans.

Post-Disaster Fertility: Hurricane Katrina and the Changing Racial Composition of New Orleans

PubMed Central

Seltzer, Nathan; Nobles, Jenna

2017-01-01

Large-scale climate events can have enduring effects on population size and composition. Natural disasters affect population fertility through multiple mechanisms, including displacement, demand for children, and reproductive care access. Fertility effects, in turn, influence the size and composition of new birth cohorts, extending the reach of climate events across generations. We study these processes in New Orleans during the decade spanning Hurricane Katrina. We combine census data, ACS data, and vital statistics data to describe fertility in New Orleans and seven comparison cities. Following Katrina, displacement contributed to a 30% decline in birth cohort size. Black fertility fell, and remained 4% below expected values through 2010. By contrast, white fertility increased by 5%. The largest share of births now occurs to white women. These fertility differences—beyond migration-driven population change—generate additional pressure on the renewal of New Orleans as a city in which the black population is substantially smaller in the disaster’s wake. PMID:29200546

Protein kinase CK2 modulates IL-6 expression in inflammatory breast cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drygin, Denis, E-mail: ddrygin@cylenepharma.com; Ho, Caroline B.; Omori, Mayuko

Highlights: Black-Right-Pointing-Pointer We examine the potential cross-talk between CK2 and IL-6. Black-Right-Pointing-Pointer Inhibition of CK2 by siRNA or CX-4945 inhibits expression of IL-6 in models of IBC. Black-Right-Pointing-Pointer Treatment of IBC patient in the clinic with CX-4945 reduces her IL-6 plasma levels. Black-Right-Pointing-Pointer We demonstrate that CK2 is a potential therapeutic target for IL-6 driven diseases. -- Abstract: Inflammatory breast cancer is driven by pro-angiogenic and pro-inflammatory cytokines. One of them Interleukin-6 (IL-6) is implicated in cancer cell proliferation and survival, and promotes angiogenesis, inflammation and metastasis. While IL-6 has been shown to be upregulated by several oncogenes, the mechanismmore » behind this phenomenon is not well characterized. Here we demonstrate that the pleotropic Serine/Threonine kinase CK2 is implicated in the regulation of IL-6 expression in a model of inflammatory breast cancer. We used siRNAs targeted toward CK2 and a selective small molecule inhibitor of CK2, CX-4945, to inhibit the expression and thus suppress the secretion of IL-6 in in vitro as well as in vivo models. Moreover, we report that in a clinical trial, CX-4945 was able to dramatically reduce IL-6 levels in plasma of an inflammatory breast cancer patient. Our data shed a new light on the regulation of IL-6 expression and position CX-4945 and potentially other inhibitors of CK2, for the treatment of IL-6-driven cancers and possibly other diseases where IL-6 is instrumental, including rheumatoid arthritis.« less

Momentum-driven Winds from Radiatively Efficient Black Hole Accretion and Their Impact on Galaxies

NASA Astrophysics Data System (ADS)

Brennan, Ryan; Choi, Ena; Somerville, Rachel S.; Hirschmann, Michaela; Naab, Thorsten; Ostriker, Jeremiah P.

2018-06-01

We explore the effect of momentum-driven winds representing radiation-pressure-driven outflows from accretion onto supermassive black holes in a set of numerical hydrodynamical simulations. We explore two matched sets of cosmological zoom-in runs of 24 halos with masses ∼1012.0–1013.4 M ⊙ run with two different feedback models. Our “NoAGN” model includes stellar feedback via UV heating, stellar winds and supernovae, photoelectric heating, and cosmic X-ray background heating from a metagalactic background. Our fiducial “MrAGN” model is identical except that it also includes a model for black hole seeding and accretion, as well as heating and momentum injection associated with the radiation from black hole accretion. Our MrAGN model launches galactic outflows, which result in both “ejective” feedback—the outflows themselves that drive gas out of galaxies—and “preventative” feedback, which suppresses the inflow of new and recycling gas. As much as 80% of outflowing galactic gas can be expelled, and accretion can be suppressed by as much as a factor of 30 in the MrAGN runs when compared with the NoAGN runs. The histories of NoAGN galaxies are recycling dominated, with ∼70% of material that leaves the galaxy eventually returning, and the majority of outflowing gas reaccretes on 1 Gyr timescales without AGN feedback. Outflowing gas in the MrAGN runs has a higher characteristic velocity (500–1000 km s‑1 versus 100–300 km s‑1 for outflowing NoAGN gas) and travels as far as a few megaparsecs. Only ∼10% of ejected material is reaccreted in the MrAGN galaxies.

Turn the temperature to turquoise: cues for colour change in the male chameleon grasshopper (Kosciuscola tristis) (Orthoptera: Acrididae).

PubMed

Umbers, Kate D L

2011-09-01

Rapid, reversible colour change is unusual in animals, but is a feature of male chameleon grasshoppers (Kosciuscola tristis). Understanding what triggers this colour change is paramount to developing hypotheses explaining its evolutionary significance. In a series of manipulative experiments the author quantified the effects of temperature, and time of day, as well as internal body temperature, on the colour of male K. tristis. The results suggest that male chameleon grasshoppers change colour primarily in response to temperature and that the rate of colour change varies considerably, with the change from black to turquoise occurring up to 10 times faster than the reverse. Body temperature changed quickly (within 10min) in response to changes in ambient temperature, but colour change did not match this speed and thus colour is decoupled from internal temperature. This indicates that male colour change is driven primarily by ambient temperature but that their colour does not necessarily reflect current internal temperature. I propose several functional hypotheses for male colour change in K. tristis. Copyright © 2011 Elsevier Ltd. All rights reserved.

PrEP Chicago: A randomized controlled peer change agent intervention to promote the adoption of pre-exposure prophylaxis for HIV prevention among young Black men who have sex with men.

PubMed

Young, Lindsay E; Schumm, Phil; Alon, Leigh; Bouris, Alida; Ferreira, Matthew; Hill, Brandon; Khanna, Aditya S; Valente, Thomas W; Schneider, John A

2018-02-01

Advances in biomedical prevention strategies such as pre-exposure prophylaxis (PrEP) represent a new opportunity for reducing HIV incidence among young Black men who have sex with men, for whom the number of new HIV infections continues to rise. However, studies have documented low rates of PrEP uptake in this community. Research suggests that the peer networks of young Black men who have sex with men play important roles in their sexual health decisions. PrEP Chicago is a randomized controlled trial network intervention designed to increase PrEP uptake among young Black men who have sex with men living in Chicago. The aims of this study are twofold. Aim 1 is to estimate the effectiveness of a peer change agent intervention for (1) increasing the number of referrals made to a PrEP information line, (2) increasing the rate of PrEP adoption among non-participant peers, and (3) increasing PrEP knowledge, attitudes, and intentions among participants. Aim 2 is to determine the individual and network variables that explain peer change agent effectiveness. PrEP Chicago is a social network intervention that utilizes the influence of peer change agents to link young Black men who have sex with men in Chicago to PrEP. Young Black men who have sex with men were recruited using respondent-driven sampling. Once screened for eligibility, participants were randomly assigned to either one of two treatment sequences: (1) intervention treatment in Year 1 followed by a minimal contact attention control in Year 2 or (2) the minimal contact attention control in Year 1 followed by treatment in Year 2. The treatment consists of a PrEP/peer change agent training workshop followed by booster calls for 12 months. The attention control consists of a sex diary activity designed to help participants assess sexual risk. Psychosocial, sexual health, and network data are collected from all participants at baseline and at 12- and 24-month follow-ups. In total, 423 participants aged 18-35 have been enrolled (more than 100% target enrollment) and have completed baseline data collection. A majority of participants in both intervention and control groups reported having heard of PrEP before enrolling in the study, yet also reported having had no current or prior experience taking PrEP. Statistical analyses await completion of Year 1 of the trial in March 2018. PrEP Chicago addresses a gap in HIV prevention research and intervention design by utilizing the existing social networks among young Black men who have sex with men as mechanisms for information diffusion, behavioral influence, social support, and empowerment. Therefore, interventions that leverage peer influence processes to facilitate PrEP uptake are promising strategies to improve sexual health engagement and overcome disparities in outcomes among this at-risk population.

Thermally driven microfluidic pumping via reversible shape memory polymers

NASA Astrophysics Data System (ADS)

Robertson, J. M.; Rodriguez, R. X.; Holmes, L. R., Jr.; Mather, P. T.; Wetzel, E. D.

2016-08-01

The need exists for autonomous microfluidic pumping systems that utilize environmental cues to transport fluid within a network of channels for such purposes as heat distribution, self-healing, or optical reconfiguration. Here, we report on reversible thermally driven microfluidic pumping enabled by two-way shape memory polymers. After developing a suitable shape memory polymer (SMP) through variation in the crosslink density, thin and flexible microfluidic devices were constructed by lamination of plastic films with channels defined by laser-cutting of double-sided adhesive film. SMP blisters integrated into the devices provide thermally driven pumping, while opposing elastic blisters are used to generate backpressure for reversible operation. Thermal cycling of the device was found to drive reversible fluid flow: upon heating to 60 °C, the SMP rapidly contracted to fill the surface channels with a transparent fluid, and upon cooling to 8 °C the flow reversed and the channel re-filled with black ink. Combined with a metallized backing layer, this device results in refection of incident light at high temperatures and absorption of light (at the portions covered with channels) at low temperatures. We discuss power-free, autonomous applications ranging from thermal regulation of structures to thermal indication via color change.

Filling a SMBH accretion disk atmosphere at small and intermediate radii

NASA Astrophysics Data System (ADS)

Karas, Vladimir; Czerny, Bozena; Kunneriath, Devaky

2017-08-01

The medium above an accretion disk is highly diluted and hot. An efficient mechanism to deliver particles and dust grains is an open question; apparently, different processes must be in operation. We discuss an interplay of two different scenarios, where the material is elevated from the plane of an equatorial accretion disk into a corona near a supermassive black hole: (i) an electromagnetically induced transport, which can be driven by magnetic field of stars passing across an accretion disk (Karas et al., 2017); and (ii) radiatively driven acceleration by radiation emerging from the disk (Czerny et al 2015), which can launch a dusty wind near above the dust sublimation radius. The former process can operate in the vicinity of a supermassive black hole (SMBH) surrounded by a dense nuclear star-cluster. The latter process involves the effect of radiation pressure from various sources - stars, accretion disc, and the central accreting SMBH; it can help filling the Broad-Line Region against the vertical component of the black hole gravitational attraction and the accretion disk self-gravity at radius about a few $\\times 10^3 R_g$.

Direct Observation of Accretion onto a Hypernova's Newly Formed Black Hole

NASA Astrophysics Data System (ADS)

Milisavljevic, Dan

2017-09-01

Models of energetic core-collapse supernovae and long-duration gamma-ray bursts often invoke engine-driven scenarios associated with the formation of compact objects that input energy into the explosion. To date, only indirect evidence of black holes or magnetars formed in these events exists from observations obtained when the explosions are most luminous. Here we request a modest 15 ks Chandra pilot observation of the exceptionally important nearby hypernova SN2002ap to test models that predict X-ray emission associated with its remnant black hole to be detectable after 15 yr of ejecta expansion. Direct observation a newly formed "baby" black hole would be a landmark discovery capable of opening up new ways to investigate fundamental aspects of the core collapse process.

Black Hole Formation in Randall-Sundrum II Braneworlds.

PubMed

Wang, Daoyan; Choptuik, Matthew W

2016-07-01

We present the first numerical study of the full dynamics of a braneworld scenario, working within the framework of the single brane model of Randall and Sundrum. In particular, we study the process of gravitational collapse driven by a massless scalar field which is confined to the brane. Imposing spherical symmetry on the brane, we show that the evolutions of sufficiently strong initial configurations of the scalar field result in black holes that have finite extension into the bulk. Furthermore, we find preliminary evidence that the black holes generated form a unique sequence, irrespective of the details of the initial data. The black hole solutions we obtain from dynamical evolutions are consistent with those previously computed from a static vacuum ansatz.

Making the Case for the Outlier: Researcher Reflections of an African-American Female Deputy Superintendent Who Decided to Close the Achievement Gap

ERIC Educational Resources Information Center

Beard, Karen Stansberry

2012-01-01

This article presents researcher reflections of a case study of a Black female deputy superintendent who made the value-driven decision to close the achievement gap in her district. I posit that she is an outlier because she is Black and female in a predominantly white male field of practice, she effectively closed the achievement gap through her…

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

PubMed Central

Thomas, Kevin J. A.

2014-01-01

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

Very Broad [O III] λλ4959, 5007 Emission from the NGC 4472 Globular Cluster RZ 2109 and Implications for the Mass of Its Black Hole X-Ray Source

NASA Astrophysics Data System (ADS)

Zepf, Stephen E.; Stern, Daniel; Maccarone, Thomas J.; Kundu, Arunav; Kamionkowski, Marc; Rhode, Katherine L.; Salzer, John J.; Ciardullo, Robin; Gronwall, Caryl

2008-08-01

We present Keck LRIS spectroscopy of the black hole-hosting globular cluster RZ 2109 in the Virgo elliptical galaxy NGC 4472. We find that this object has extraordinarily broad [O III] λ5007 and [O III] λ4959 emission lines, with velocity widths of approximately 2000 km s-1. This result has significant implications for the nature of this accreting black hole system and the mass of the globular cluster black hole. We show that the broad [O III] λ5007 emission must arise from material driven at high velocity from the black hole system. This is because the volume available near the black hole is too small by many orders of magnitude to have enough [O III]-emitting atoms to account for the observed L([O III] λ5007) at high velocities, even if this volume is filled with oxygen at the critical density for [O III] λ5007. The Balmer emission is also weak, indicating the observed [O III] is not due to shocks. We therefore conclude that the [O III] λλ4959, 5007 is produced by photoionization of material driven across the cluster. The only known way to drive significant material at high velocity is for a system accreting mass near or above its Eddington limit, which indicates a stellar-mass black hole. Since it is dynamically implausible to form an accreting stellar-mass black hole system in a globular cluster with an intermediate-mass black hole (IMBH), it appears this massive globular cluster does not have an IMBH. We discuss further tests of this conclusion, and its implications for the MBH - Mstellar and MBH - σ relations. Based on observations made at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation.

Racial bias is associated with ingroup death rate for Blacks and Whites: Insights from Project Implicit.

PubMed

Leitner, Jordan B; Hehman, Eric; Ayduk, Ozlem; Mendoza-Denton, Rodolfo

2016-10-20

Research suggests that, among Whites, racial bias predicts negative ingroup health outcomes. However, little is known about whether racial bias predicts ingroup health outcomes among minority populations. The aim of the current research was to understand whether racial bias predicts negative ingroup health outcomes for Blacks. We compiled racial bias responses from 250,665 Blacks and 1,391,632 Whites to generate county-level estimates of Blacks' and Whites' implicit and explicit biases towards each other. We then examined the degree to which these biases predicted ingroup death rate from circulatory-related diseases. In counties where Blacks harbored more implicit bias towards Whites, Blacks died at a higher rate. Additionally, consistent with previous research, in counties where Whites harbored more explicit bias towards Blacks, Whites died at a higher rate. These links between racial bias and ingroup death rate were independent of county-level socio-demographic characteristics, and racial biases from the outgroup in the same county. Findings indicate that racial bias is related to negative ingroup health outcomes for both Blacks and Whites, though this relationship is driven by implicit bias for Blacks, and explicit bias for Whites. Copyright © 2016 Elsevier Ltd. All rights reserved.

Outflow-driven Transients from the Birth of Binary Black Holes. II. Primary-induced Accretion Transients

NASA Astrophysics Data System (ADS)

Kimura, Shigeo S.; Murase, Kohta; Mészáros, Peter

2017-12-01

We discuss the electromagnetic radiation from newborn binary black holes (BBHs). As a consequence of the evolution of massive stellar binaries, a binary consisting of a primary black hole (BH) and a secondary Wolf–Rayet star is expected as a BBH progenitor system. We investigate optical transients from the birth of BBHs powered by the Bondi–Hoyle–Lyttleton accretion onto the primary BH, which occur ∼1–10 Gyr earlier than gravitational-wave signals at the BH–BH merger. When the secondary massive star collapses into a BH, it may eject a fraction of its outer material and may form a disk around the primary BH and induces a powerful disk wind. These primary-induced winds can lead to optical transients with a kinetic energy of ∼1047–3 × 1048 erg, an ejecta velocity of 108–109 cm s‑1, a duration of a few days, and an absolute magnitude ranging from about ‑11 to ‑14. The light curves and late-time spectra of these transients are distinctive from those of ordinary supernovae, and detection of this type of transient is possible by future optical transient surveys if the event rate of this transient is comparable to the merger rate of BBHs. This paper focuses on the emissions from disk-driven transients induced by the primary BH, different from Paper I, which focuses on wind-driven transients from the tidally locked secondary massive star.

Probing the Magnetic Field Structure in Sgr A* on Black Hole Horizon Scales with Polarized Radiative Transfer Simulations

NASA Astrophysics Data System (ADS)

Gold, Roman; McKinney, Jonathan C.; Johnson, Michael D.; Doeleman, Sheperd S.

2017-03-01

Magnetic fields are believed to drive accretion and relativistic jets in black hole accretion systems, but the magnetic field structure that controls these phenomena remains uncertain. We perform general relativistic (GR) polarized radiative transfer of time-dependent three-dimensional GR magnetohydrodynamical simulations to model thermal synchrotron emission from the Galactic Center source Sagittarius A* (Sgr A*). We compare our results to new polarimetry measurements by the Event Horizon Telescope (EHT) and show how polarization in the visibility (Fourier) domain distinguishes and constrains accretion flow models with different magnetic field structures. These include models with small-scale fields in disks driven by the magnetorotational instability as well as models with large-scale ordered fields in magnetically arrested disks. We also consider different electron temperature and jet mass-loading prescriptions that control the brightness of the disk, funnel-wall jet, and Blandford-Znajek-driven funnel jet. Our comparisons between the simulations and observations favor models with ordered magnetic fields near the black hole event horizon in Sgr A*, though both disk- and jet-dominated emission can satisfactorily explain most of the current EHT data. We also discuss how the black hole shadow can be filled-in by jet emission or mimicked by the absence of funnel jet emission. We show that stronger model constraints should be possible with upcoming circular polarization and higher frequency (349 GHz) measurements.

Last hired, first fired? Black-white unemployment and the business cycle.

PubMed

Couch, Kenneth A; Fairlie, Robert

2010-02-01

Studies have tested the claim that blacks are the last hired during periods of economic growth and the first fired in recessions by examining the movement of relative unemployment rates over the business cycle. Any conclusion drawn from this type of analysis must be viewed as tentative because cyclical movements in the underlying transitions into and out of unemployment are not examined. Using Current Population Survey data matched across adjacent months from 1989-2004, this article provides the first detailed examination of labor market transitions for prime-age black and white men to test the last hired, first fired hypothesis. Considerable evidence is presented that blacks are the first fired as the business cycle weakens. However no evidence is found that blacks are the last hired. Instead, blacks appear to be initially hired from the ranks of the unemployed early in the business cycle and later are drawn from nonparticipation. The narrowing of the racial unemployment gap near the peak of the business cycle is driven by a reduction in the rate of job loss for blacks rather than increases in hiring.

Last Hired, First Fired? Black-White Unemployment and the Business Cycle

PubMed Central

COUCH, KENNETH A.; FAIRLIE, ROBERT

2010-01-01

Studies have tested the claim that blacks are the last hired during periods of economic growth and the first fired in recessions by examining the movement of relative unemployment rates over the business cycle. Any conclusion drawn from this type of analysis must be viewed as tentative because cyclical movements in the underlying transitions into and out of unemployment are not examined. Using Current Population Survey data matched across adjacent months from 1989–2004, this article provides the first detailed examination of labor market transitions for prime-age black and white men to test the last hired, first fired hypothesis. Considerable evidence is presented that blacks are the first fired as the business cycle weakens. However, no evidence is found that blacks are the last hired. Instead, blacks appear to be initially hired from the ranks of the unemployed early in the business cycle and later are drawn from nonparticipation. The narrowing of the racial unemployment gap near the peak of the business cycle is driven by a reduction in the rate of job loss for blacks rather than increases in hiring. PMID:20355692

A Concept of the Differentially Driven Three Wheeled Robot

NASA Astrophysics Data System (ADS)

Kelemen, M.; Colville, D. J.; Kelemenová, T.; Virgala, I.; Miková, L.

2013-08-01

The paper deals with the concept of a differentially driven three wheeled robot. The main task for the robot is to follow the navigation black line on white ground. The robot also contains anti-collision sensors for avoiding obstacles on track. Students learn how to deal with signals from sensors and how to control DC motors. Students work with the controller and develop the locomotion algorithm and can attend a competition

Electrically Driven Photonic Crystal Nanocavity Devices

DTIC Science & Technology

2012-01-01

material, here gallium arsenide and indium arsenide self- assembled quantum dots (QDs). QDs are preferred for the gain medium because they can have...blue points ) and 150 K (green points ). The black lines are linear fits to the above threshold output power of the lasers, which are used to find the...SHAMBAT et al.: ELECTRICALLY DRIVEN PHOTONIC CRYSTAL NANOCAVITY DEVICES 1707 Fig. 13. (a) Tilted SEM picture of a fabricated triple cavity device. The in

Winds of Change

NASA Image and Video Library

2010-03-05

Observation Date: 1 pointing on Dec 4, 2000 and 9 pointings between Nov 18 and Dec 5, 2008. Distance Estimate: About 50 million light years away. This is a composite image of NGC 1068, one of the nearest and brightest galaxies containing a rapidly growing supermassive black hole. The X-ray images and spectra obtained using Chandra's High Energy Transmission Grating Spectrometer show that a strong wind is being driven away from the center of NGC 1068 at a rate of about a million miles per hour. This wind is likely generated as surrounding gas is accelerated and heated as it swirls toward the black hole. A portion of the gas is pulled into the black hole, but some of it is blown away. High energy X-rays produced by the gas near the black hole heat the ouflowing gas, causing it to glow at lower X-ray energies. X-ray data from the Chandra X-ray Observatory are shown in red, optical data from the Hubble Space Telescope in green and radio data from the Very Large Array in blue. The spiral structure of NGC 1068 is shown by the X-ray and optical data, and a jet powered by the central supermassive black hole is shown by the radio data. This Chandra study is much deeper than previous X-ray observations. Using this data, researchers believe that each year several times the mass of our sun is being deposited out to large distances, about 3,000 light years from the black hole. The wind likely carries enough energy to heat the surrounding gas and suppress extra star formation. These results help explain how a supermassive black hole can alter the evolution of its host galaxy. It has long been suspected that material blown away from a black hole can affect its environment, but a key question has been whether such "black hole blowback" typically delivers enough power to have a significant impact. NGC 1068 is located about 50 million light years from Earth and contains a supermassive black hole about twice as massive as the one in the middle of the Milky Way Galaxy. Image Credit: X-ray (NASA/CXC/ MIT/C.Canizares, D.Evans et al), Optical (NASA/STScI), Radio (NSF/ NRAO/VLA)

Acceleration of black hole universe

NASA Astrophysics Data System (ADS)

Zhang, T. X.; Frederick, C.

2014-01-01

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

Where to Focus Efforts to Reduce the Black-White Disparity In Stroke Mortality: Incidence vs. Case-Fatality?

PubMed Central

Howard, George; Moy, Claudia S.; Howard, Virginia J.; McClure, Leslie A.; Kleindorfer, Dawn O.; Kissela, Brett M.; Judd, Suzanne E.; Unverzagt, Fredrick W.; Soliman, Elsayed Z.; Safford, Monika M.; Cushman, Mary; Flaherty, Matthew L.; Wadley, Virginia G.

2016-01-01

Background and Purpose At age 45, Blacks have a stroke mortality approximately 3-times greater than their White counterparts, with a declining disparity at older ages. We assess whether this Black-White disparity in stroke mortality is attributable to a Black-White disparity in stroke incidence versus a disparity in case-fatality. Methods We first assess if Black-White differences in stroke mortality within 29,681 participants in the REasons for Geographic And Racial Differences in Stroke (REGARDS) cohort reflect national Black-White differences in stroke mortality, and then assess the degree to which Black-White differences in stroke incidence or 30-day case-fatality after stroke contribute to the disparities in stroke mortality. Results The pattern of stroke mortality within the study mirrors the national pattern, with the Black-to-White hazard ratio of approximately 4.0 at age 45 decreasing to approximately 1.0 at age 85. The pattern of Black-to-White disparities in stroke incidence shows a similar pattern, but no evidence of a corresponding disparity in stroke case-fatality. Discussion These findings show that the Black-White differences in stroke mortality are largely driven by differences in stroke incidence, with case fatality playing at most a minor role. Therefore to reduce the Black-White disparity in stroke mortality, interventions need to focus on prevention of stroke in Blacks. PMID:27256672

AGN Space Telescope and Optical Reverberation Mapping Project. IV. Velocity-Delay Mapping of Broad Emission Lines in NGC 5548

NASA Astrophysics Data System (ADS)

Horne, Keith D.; Agn Storm Team

2015-01-01

Two-dimensional velocity-delay maps of AGN broad emission line regions can be recovered by modelling observations of reverberating emission-line profiles on the assumption that the line profile variations are driven by changes in ionising radiation from a compact source near the black hole. The observable light travel time delay resolves spatial structure on iso-delay paraboloids, while the doppler shift resolves kinematic structure along the observer's line-of-sight. Velocity-delay maps will be presented and briefly discussed for the Lyman alpha, CIV and Hbeta line profiles based on the HST and ground-based spectrophotometric monitoring of NGC 5548 during the 2014 AGN STORM campaign.

Stroke incidence is decreasing in whites but not in blacks: a population-based estimate of temporal trends in stroke incidence from the Greater Cincinnati/Northern Kentucky Stroke Study.

PubMed

Kleindorfer, Dawn O; Khoury, Jane; Moomaw, Charles J; Alwell, Kathleen; Woo, Daniel; Flaherty, Matthew L; Khatri, Pooja; Adeoye, Opeolu; Ferioli, Simona; Broderick, Joseph P; Kissela, Brett M

2010-07-01

Although other studies (in largely white populations) have found that stroke incidence declined during the 1990s, we previously reported that stroke incidence in our population (18% of which was black) did not change during that decade and that incidence rates in blacks were significantly higher than in whites. We sought to update temporal trends in stroke incidence by adding new data obtained from our large, biracial population in 2005. The objective of this study was to examine temporal trends in stroke incidence and case-fatality within a large biracial population over time by comparing stroke incidence rates from 1993 to 1994, 1999, and 2005. Within the Greater Cincinnati/Northern Kentucky population of 1.3 million, all strokes among area residents were ascertained at all local hospitals during July 1993 to June 19/94 and calendar years 1999 and 2005. A sampling scheme was used to ascertain cases in the out-of-hospital setting. Only first-ever strokes were included in this analysis. Race-specific incidence rates, standardized to the 2000 US Census population, and case-fatality rates were calculated. The number of physician-confirmed first-ever strokes in patients >or=20 years of age was 1942 in 1993 to 1994, 2041 in 1999, and 1921 in 2005. In all study periods, blacks had higher stroke incidence than whites, and case-fatality rates were similar between races. In contrast to previous study periods, we found a significant decrease in overall stroke incidence in 2005. When stratified by race and stroke subtype, this change was driven by a decrease in ischemic stroke incidence among whites, whereas ischemic stroke incidence in blacks was unchanged. Hemorrhagic stroke incidence was unchanged in both races. For the first time, we report a significant decrease in stroke incidence within our population, which is consistent with other reports in the literature. This decrease was found only among whites, which suggests a worsening of the racial disparity in stroke incidence.

Stroke Incidence is Decreasing in Whites, but Not in Blacks: A Population-Based Estimate of Temporal Trends in Stroke Incidence from the Greater Cincinnati/Northern Kentucky Stroke Study

PubMed Central

Kleindorfer, Dawn; Khoury, Jane; Moomaw, Charles J.; Alwell, Kathleen; Woo, Daniel; Flaherty, Matthew L.; Khatri, Pooja; Adeoye, Opeolu; Ferioli, Simona; Broderick, Joseph P.; Kissela, Brett M.

2010-01-01

Context While other studies (in largely white populations) have found that stroke incidence declined during the 1990s, we previously reported that stroke incidence in our population (18% of which was black) did not change during that decade and that incidence rates in blacks were significantly higher than in whites. We sought to update temporal trends in stroke incidence by adding new data obtained from our large, bi-racial population in 2005. Objective To examine temporal trends in stroke incidence and case fatality within a large, biracial population over time, by comparing stroke incidence rates from 1993/94, 1999, and 2005. Design, Setting, and Participants Within the Greater Cincinnati/Northern Kentucky population of 1.3 million, all strokes among area residents were ascertained at all local hospitals during 7/93-6/94 and calendar years 1999 and 2005. A sampling scheme was used to ascertain cases in the out-of-hospital setting. Only first-ever strokes were included in this analysis. Race-specific incidence rates, standardized to the 2000 U.S. Census population, and case-fatality rates were calculated. Results The number of physician-confirmed first-ever strokes in patients ≥20 years of age was 1,942 in 1993/94, 2,041 in 1999, and 1,921 in 2005. In all study periods, blacks had higher stroke incidence than whites, and case fatality rates were similar between races. In contrast to previous study periods, we found a significant decrease in overall stroke incidence in 2005. When stratified by race and stroke subtype, this change was driven by a decrease in ischemic stroke incidence among whites, while ischemic stroke incidence in blacks was unchanged. Hemorrhagic stroke incidence was unchanged in both races. Discussion For the first time, we report a significant decrease in stroke incidence within our population, which is consistent with other reports in the literature. This decrease was found only among whites, which suggests a worsening of the racial disparity in stroke incidence. PMID:20489177

The black and white coatings on Ti-6Al-4V alloy or pure titanium by plasma electrolytic oxidation in concentrated silicate electrolyte

NASA Astrophysics Data System (ADS)

Han, Jun-xiang; Cheng, Yu-lin; Tu, Wen-bin; Zhan, Ting-Yan; Cheng, Ying-liang

2018-01-01

Black TiO2 has triggered scientific interest due to its unique properties such as enhanced solar-driven photocatalytic activity. In this paper, plasma electrolytic oxidation (PEO) treatment of Ti-6Al-4V alloy has been carried out in concentrated sodium silicate electrolyte. Silica-based black and white TiO2 coatings respectively have been obtained by controlling the oxidation time. The black coating, which was formed with a short treatment time, shows good corrosion resistance and the black appearance can be attributed to the presence of Ti2+ and Ti3+ in the coating. The lower valence titanium ions are absent in the white coatings and they also contain relatively higher Na content compared to the black coatings. The white coatings have great surface roughnesses and super hydrophilicity. The bonding strengths of the black and white coatings on the Ti-6Al-4V alloy are ∼14.4 and 4.3 MPa, respectively. The vanadium contributes little to the black appearance of the coating on Ti6Al4V alloy, since the same phenomena occur for the PEO of a pure titanium substrate.

Galaxy evolution. Black hole feedback in the luminous quasar PDS 456.

PubMed

Nardini, E; Reeves, J N; Gofford, J; Harrison, F A; Risaliti, G; Braito, V; Costa, M T; Matzeu, G A; Walton, D J; Behar, E; Boggs, S E; Christensen, F E; Craig, W W; Hailey, C J; Matt, G; Miller, J M; O'Brien, P T; Stern, D; Turner, T J; Ward, M J

2015-02-20

The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband x-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10(46) ergs per second is enough to provide the feedback required by models of black hole and host galaxy coevolution. Copyright © 2015, American Association for the Advancement of Science.

Constructing Black Titania with Unique Nanocage Structure for Solar Desalination.

PubMed

Zhu, Guilian; Xu, Jijian; Zhao, Wenli; Huang, Fuqiang

2016-11-23

Solar desalination driven by solar radiation as heat source is freely available, however, hindered by low efficiency. Herein, we first design and synthesize black titania with a unique nanocage structure simultaneously with light trapping effect to enhance light harvesting, well-crystallized interconnected nanograins to accelerate the heat transfer from titania to water and with opening mesopores (4-10 nm) to facilitate the permeation of water vapor. Furthermore, the coated self-floating black titania nanocages film localizes the temperature increase at the water-air interface rather than uniformly heating the bulk of the water, which ultimately results in a solar-thermal conversion efficiency as high as 70.9% under a simulated solar light with an intensity of 1 kW m -2 (1 sun). This finding should inspire new black materials with rationally designed structure for superior solar desalination performance.

BINARY BLACK HOLES, GAS SLOSHING, AND COLD FRONTS IN THE X-RAY HALO HOSTING 4C+37.11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrade-Santos, Felipe; Bogdán, Ákos; Forman, William R.

We analyzed deep Chandra ACIS-I exposures of the cluster-scale X-ray halo surrounding the radio source 4C+37.11. This remarkable system hosts the closest resolved pair of super-massive black holes and an exceptionally luminous elliptical galaxy, the likely product of a series of past mergers. We characterize the halo with r {sub 500} ∼ 0.95 Mpc, M {sub 500} = 2.5 ± 0.2 × 10{sup 14} M {sub ⊙}, kT = 4.6 ± 0.2 keV, and a gas mass of M {sub g,500} = 2.2 ± 0.1 × 10{sup 13} M {sub ⊙}. The gas mass fraction within r {sub 500} ismore » f {sub g} = 0.09 ± 0.01. The entropy profile shows large non-gravitational heating in the central regions. We see several surface brightness jumps, associated with substantial temperature and density changes but approximate pressure equilibrium, implying that these are sloshing structures driven by a recent merger. A residual intensity image shows a core spiral structure closely matching that seen in the Perseus cluster, although at z = 0.055 the spiral pattern is less distinct. We infer that the most recent merger occurred 1–2 Gyr ago and that the event that brought the two observed super-massive black holes to the system core is even older. Under this interpretation, the black hole binary pair has, unusually, remained at a parsec-scale separation for more than 2 Gyr.« less

Prioritizing material recovery for end-of-life printed circuit boards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Xue, E-mail: xxw6590@rit.edu; Gaustad, Gabrielle, E-mail: gabrielle.gaustad@rit.edu

2012-10-15

Highlights: Black-Right-Pointing-Pointer Material recovery driven by composition, choice of ranking, and weighting. Black-Right-Pointing-Pointer Economic potential for new recycling technologies quantified for several metrics. Black-Right-Pointing-Pointer Indicators developed for materials incurring high eco-toxicity costs. Black-Right-Pointing-Pointer Methodology useful for a variety of stakeholders, particularly policy-makers. - Abstract: The increasing growth in generation of electronic waste (e-waste) motivates a variety of waste reduction research. Printed circuit boards (PCBs) are an important sub-set of the overall e-waste stream due to the high value of the materials contained within them and potential toxicity. This work explores several environmental and economic metrics for prioritizing the recovery ofmore » materials from end-of-life PCBs. A weighted sum model is used to investigate the trade-offs among economic value, energy saving potentials, and eco-toxicity. Results show that given equal weights for these three sustainability criteria gold has the highest recovery priority, followed by copper, palladium, aluminum, tin, lead, platinum, nickel, zinc, and silver. However, recovery priority will change significantly due to variation in the composition of PCBs, choice of ranking metrics, and weighting factors when scoring multiple metrics. These results can be used by waste management decision-makers to quantify the value and environmental savings potential for recycling technology development and infrastructure. They can also be extended by policy-makers to inform possible penalties for land-filling PCBs or exporting to the informal recycling sector. The importance of weighting factors when examining recovery trade-offs, particularly for policies regarding PCB collection and recycling are explored further.« less

Photonically driven DNA nanomachine with hybrid functions towards cell measurement

NASA Astrophysics Data System (ADS)

Ogura, Yusuke; Nishimura, Takahiro; Yamada, Kenji; Tanida, Jun

2018-02-01

Physical properties of a cell are often valuable information about the status of the cell, and developing technologies to measure such properties is important to enhance the progress in, for example, diagnosis of diseases. In this paper, we present a photonically driven DNA nanomachine with hybrid functions: providing a physical operation to a cell and reporting the cell's response. The DNA nanomachine can be controlled according to optical signals, and therefore the measurement is achieved locally at designated positions and at desired times. Black hole quenchers (BHQs) are introduced to drive the DNA nanomachine using light. When the DNA nanomachine is irradiated with the light at the excitation wavelength of the BHQs, the thermal energy is produced from the BHQs to drive the DNA nanomachine. To demonstrate a basic functionality, we constructed a DNA nanomachine that transformed between a linear conformation and a hairpin-like conformation depending on the presence or absence of a controlling DNA. This conformation change will be able to provide a force to deform cells as a physical operation. The response of the cell is reported as fluorescence resonance energy transfer (FRET) signals. An experimental result demonstrated that the FRET signal changed according to the presence or absence of the controlling DNA. The method is expected to be useful in measuring the stiffness of a cell.

Respondent-Driven Sampling in a Multi-Site Study of Black and Latino Men Who Have Sex with Men.

PubMed

Murrill, Christopher S; Bingham, Trista; Lauby, Jennifer; Liu, Kai-Lih; Wheeler, Darrell; Carballo-Diéguez, Alex; Marks, Gary; Millett, Gregorio A

2016-02-01

Respondent-driven sampling (RDS) was used to recruit four samples of Black and Latino men who have sex with men (MSM) in three metropolitan areas to measure HIV prevalence and sexual and drug use behaviors. We compared demographic and behavioral risk characteristics of participants across sites, assessed the extent to which the RDS statistical adjustment procedure provides estimates that differ from the crude results, and summarized our experiences using RDS. From June 2005 to March 2006 a total of 2,235 MSM were recruited and interviewed: 614 Black MSM and 516 Latino MSM in New York City, 540 Black MSM in Philadelphia, and 565 Latino MSM in Los Angeles County. Crude point estimates for demographic characteristics, behavioral risk factors and HIV prevalence were calculated for each of the four samples. RDS Analysis Tool was used to obtain population-based estimates of each sampled population's characteristics. RDS adjusted estimates were similar to the crude estimates for each study sample on demographic characteristics such as age, income, education and employment status. Adjusted estimates of the prevalence of risk behaviors were lower than the crude estimates, and for three of the study samples, the adjusted HIV prevalence estimates were lower than the crude estimates. However, even the adjusted HIV prevalence estimates were higher than what has been previously estimated for these groups of MSM in these cities. Each site faced unique circumstances in implementing RDS. Our experience in using RDS among Black and Latino MSM resulted in diverse recruitment patterns and uncertainties in the estimated HIV prevalence and risk behaviors by study site. Copyright © 2016. Published by Elsevier Inc.

Strong disk winds traced throughout outbursts in black-hole X-ray binaries

NASA Astrophysics Data System (ADS)

Tetarenko, B. E.; Lasota, J.-P.; Heinke, C. O.; Dubus, G.; Sivakoff, G. R.

2018-02-01

Recurring outbursts associated with matter flowing onto compact stellar remnants (such as black holes, neutron stars and white dwarfs) in close binary systems provide a way of constraining the poorly understood accretion process. The light curves of these outbursts are shaped by the efficiency of angular-momentum (and thus mass) transport in the accretion disks, which has traditionally been encoded in a viscosity parameter, α. Numerical simulations of the magneto-rotational instability that is believed to be the physical mechanism behind this transport yield values of α of roughly 0.1–0.2, consistent with values determined from observations of accreting white dwarfs. Equivalent viscosity parameters have hitherto not been estimated for disks around neutron stars or black holes. Here we report the results of an analysis of archival X-ray light curves of 21 outbursts in black-hole X-ray binaries. By applying a Bayesian approach to a model of accretion, we determine corresponding values of α of around 0.2–1.0. These high values may be interpreted as an indication either of a very high intrinsic rate of angular-momentum transport in the disk, which could be sustained by the magneto-rotational instability only if a large-scale magnetic field threads the disk, or that mass is being lost from the disk through substantial outflows, which strongly shape the outburst in the black-hole X-ray binary. The lack of correlation between our estimates of α and the accretion state of the binaries implies that such outflows can remove a substantial fraction of the disk mass in all accretion states and therefore suggests that the outflows correspond to magnetically driven disk winds rather than thermally driven ones, which require specific radiative conditions.

Strong disk winds traced throughout outbursts in black-hole X-ray binaries.

PubMed

Tetarenko, B E; Lasota, J-P; Heinke, C O; Dubus, G; Sivakoff, G R

2018-02-01

Recurring outbursts associated with matter flowing onto compact stellar remnants (such as black holes, neutron stars and white dwarfs) in close binary systems provide a way of constraining the poorly understood accretion process. The light curves of these outbursts are shaped by the efficiency of angular-momentum (and thus mass) transport in the accretion disks, which has traditionally been encoded in a viscosity parameter, α. Numerical simulations of the magneto-rotational instability that is believed to be the physical mechanism behind this transport yield values of α of roughly 0.1-0.2, consistent with values determined from observations of accreting white dwarfs. Equivalent viscosity parameters have hitherto not been estimated for disks around neutron stars or black holes. Here we report the results of an analysis of archival X-ray light curves of 21 outbursts in black-hole X-ray binaries. By applying a Bayesian approach to a model of accretion, we determine corresponding values of α of around 0.2-1.0. These high values may be interpreted as an indication either of a very high intrinsic rate of angular-momentum transport in the disk, which could be sustained by the magneto-rotational instability only if a large-scale magnetic field threads the disk, or that mass is being lost from the disk through substantial outflows, which strongly shape the outburst in the black-hole X-ray binary. The lack of correlation between our estimates of α and the accretion state of the binaries implies that such outflows can remove a substantial fraction of the disk mass in all accretion states and therefore suggests that the outflows correspond to magnetically driven disk winds rather than thermally driven ones, which require specific radiative conditions.

Probing the Magnetic Field Structure in Sgr A* on Black Hole Horizon Scales with Polarized Radiative Transfer Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gold, Roman; McKinney, Jonathan C.; Johnson, Michael D.

Magnetic fields are believed to drive accretion and relativistic jets in black hole accretion systems, but the magnetic field structure that controls these phenomena remains uncertain. We perform general relativistic (GR) polarized radiative transfer of time-dependent three-dimensional GR magnetohydrodynamical simulations to model thermal synchrotron emission from the Galactic Center source Sagittarius A* (Sgr A*). We compare our results to new polarimetry measurements by the Event Horizon Telescope (EHT) and show how polarization in the visibility (Fourier) domain distinguishes and constrains accretion flow models with different magnetic field structures. These include models with small-scale fields in disks driven by the magnetorotationalmore » instability as well as models with large-scale ordered fields in magnetically arrested disks. We also consider different electron temperature and jet mass-loading prescriptions that control the brightness of the disk, funnel-wall jet, and Blandford–Znajek-driven funnel jet. Our comparisons between the simulations and observations favor models with ordered magnetic fields near the black hole event horizon in Sgr A*, though both disk- and jet-dominated emission can satisfactorily explain most of the current EHT data. We also discuss how the black hole shadow can be filled-in by jet emission or mimicked by the absence of funnel jet emission. We show that stronger model constraints should be possible with upcoming circular polarization and higher frequency (349 GHz) measurements.« less

Racial bias in implicit danger associations generalizes to older male targets.

PubMed

Lundberg, Gustav J W; Neel, Rebecca; Lassetter, Bethany; Todd, Andrew R

2018-01-01

Across two experiments, we examined whether implicit stereotypes linking younger (~28-year-old) Black versus White men with violence and criminality extend to older (~68-year-old) Black versus White men. In Experiment 1, participants completed a sequential priming task wherein they categorized objects as guns or tools after seeing briefly-presented facial images of men who varied in age (younger versus older) and race (Black versus White). In Experiment 2, we used different face primes of younger and older Black and White men, and participants categorized words as 'threatening' or 'safe.' Results consistently revealed robust racial biases in object and word identification: Dangerous objects and words were identified more easily (faster response times, lower error rates), and non-dangerous objects and words were identified less easily, after seeing Black face primes than after seeing White face primes. Process dissociation procedure analyses, which aim to isolate the unique contributions of automatic and controlled processes to task performance, further indicated that these effects were driven entirely by racial biases in automatic processing. In neither experiment did prime age moderate racial bias, suggesting that the implicit danger associations commonly evoked by younger Black versus White men appear to generalize to older Black versus White men.

“Black Swans” of Hydrology: Can our Models Address the Science of Hydrologic Change?

NASA Astrophysics Data System (ADS)

Kumar, P.

2009-12-01

Coupled models of terrestrial hydrology and climate have grown in complexity leading to better understanding of the coupling between the hydrosphere, biosphere, and the climate system. During the past two decades, these models have evolved through generational changes as they have grown in sophistication in their ability to resolve spatial heterogeneity as well as vegetation dynamics and biogeochemistry. These developments have, in part, been driven by data collection efforts ranging from focused field campaigns to long-term observational networks, advances in remote sensing and other measurement technologies, along with sophisticated estimation and assimilation methods. However, the hydrologic cycle is changing leading to unexpected and unanticipated behavior through emergent dynamics and patterns that are not part of the historical milieu. Is there a new thinking that is needed to address this challenge? The goal of this talk is to draw from the modeling developments in the past two decades to foster a debate for moving forward.

Weak hydrological sensitivity to temperature change over land, independent of climate forcing

NASA Astrophysics Data System (ADS)

Samset, Bjorn H.

2017-04-01

As the global surface temperature changes, so will patterns and rates of precipitation. Theoretically, these changes can be understood in terms of changes to the energy balance of the atmosphere, caused by introducing drivers of climate change such as greenhouse gases, aerosols and altered insolation. Climate models, however, disagree strongly in their prediction of precipitation changes, both for historical and future emission pathways, and per degree of surface warming in idealized experiments. The latter value, often termed the apparent hydrological sensitivity, has also been found to differ substantially between climate drivers. Here, we present the global and regional hydrological sensitivity (HS) to surface temperature changes, for perturbations to CO2, CH4, sulfate and black carbon concentrations, and solar irradiance. Based on results from 10 climate models participating in the Precipitation Driver and Response Model Intercomparison Project (PDRMIP), we show how modeled global mean precipitation increases by 2-3 % per kelvin of global mean surface warming, independent of driver, when the effects of rapid adjustments are removed. Previously reported differences in response between drivers are therefore mainly ascribable to rapid atmospheric adjustment processes. All models show a sharp contrast in behavior over land and over ocean, with a strong surface temperature driven (slow) ocean HS of 3-5 %/K, while the slow land HS is only 0-2 %/K. Separating the response into convective and large-scale cloud processes, we find larger inter-model differences, in particular over land regions. Large-scale precipitation changes are most relevant at high latitudes, while the equatorial HS is dominated by convective precipitation changes. Black carbon stands out as the driver with the largest inter-model slow HS variability, and also the strongest contrast between a weak land and strong sea response. Convective precipitation in the Arctic and large scale precipitation around the Equator are found to be topics where further model investigations and observational constraints may provide rapid improvements to modelling of the precipitation response to future, CO2 dominated climate change.

Direct formation of supermassive black holes via multi-scale gas inflows in galaxy mergers.

PubMed

Mayer, L; Kazantzidis, S; Escala, A; Callegari, S

2010-08-26

Observations of distant quasars indicate that supermassive black holes of billions of solar masses already existed less than a billion years after the Big Bang. Models in which the 'seeds' of such black holes form by the collapse of primordial metal-free stars cannot explain the rapid appearance of these supermassive black holes because gas accretion is not sufficiently efficient. Alternatively, these black holes may form by direct collapse of gas within isolated protogalaxies, but current models require idealized conditions, such as metal-free gas, to prevent cooling and star formation from consuming the gas reservoir. Here we report simulations showing that mergers between massive protogalaxies naturally produce the conditions for direct collapse into a supermassive black hole with no need to suppress cooling and star formation. Merger-driven gas inflows give rise to an unstable, massive nuclear gas disk of a few billion solar masses, which funnels more than 10(8) solar masses of gas to a sub-parsec-scale gas cloud in only 100,000 years. The cloud undergoes gravitational collapse, which eventually leads to the formation of a massive black hole. The black hole can subsequently grow to a billion solar masses on timescales of about 10(8) years by accreting gas from the surrounding disk.

The role of environment in the observed Fundamental Plane of radio Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Shabala, Stanislav S.

2018-05-01

The optical Fundamental Plane of black hole activity relates radio continuum luminosity of Active Galactic Nuclei to [O III] luminosity and black hole mass. We examine the environments of low redshift (z < 0.2) radio-selected AGN, quantified through galaxy clustering, and find that halo mass provides similar mass scalings to black hole mass in the Fundamental Plane relations. AGN properties are strongly environment-dependent: massive haloes are more likely to host radiatively inefficient (low-excitation) radio AGN, as well as a higher fraction of radio luminous, extended sources. These AGN populations have different radio - optical luminosity scaling relations, and the observed mass scalings in the parent AGN sample are built up by combining populations preferentially residing in different environments. Accounting for environment-driven selection effects, the optical Fundamental Plane of supermassive black holes is likely to be mass-independent, as predicted by models.

Nonthermal plasmas around black holes, relevant collective modes, new configurations, and magnetic field amplification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coppi, B., E-mail: coppi@mit.edu

The radiation emission from Shining Black Holes is most frequently observed to have nonthermal features. It is therefore appropriate to consider relevant collective processes in plasmas surrounding black holes that contain high energy particles with nonthermal distributions in momentum space. A fluid description with significant temperature anisotropies is the simplest relevant approach. These anisotropies are shown to have a critical influence on: (a) the existence and characteristics of stationary plasma and field ring configurations, (b) the excitation of “thermo-gravitational modes” driven by temperature anisotropies and gradients that involve gravity and rotation, (c) the generation of magnetic fields over macroscopic scalemore » distances, and (d) the transport of angular momentum.« less

The effect of gauge conditions on waveforms from binary black hole coalescence

NASA Astrophysics Data System (ADS)

Bentivegna, Eloisa; Laguna, Pablo; Shoemaker, Deirdre

2006-11-01

Over the past year and a half, a number of groups have produced stable runs of a binary black hole system evolving through merger and ringdown. In [2][3], in particular, the tremendous speedup to the field was driven by special sets of gauge evolution equations, capable of handling several issues that have traditionally plagued black hole simulations: avoiding the singularity, guaranteeing a constraint satisfying solution at least in the exterior region, and advecting the holes through the numerical grid. Since several successful recipes have already been proposed, the goal of this study is to review them and analyze the consistency of the published results. A preliminary comparison of the waveform outcome of each different gauge prescription is presented.

Simulated responses of terrestrial aridity to black carbon and sulfate aerosols

NASA Astrophysics Data System (ADS)

Lin, L.; Gettelman, A.; Xu, Y.; Fu, Q.

2016-01-01

Aridity index (AI), defined as the ratio of precipitation to potential evapotranspiration (PET), is a measure of the dryness of terrestrial climate. Global climate models generally project future decreases of AI (drying) associated with global warming scenarios driven by increasing greenhouse gas and declining aerosols. Given their different effects in the climate system, scattering and absorbing aerosols may affect AI differently. Here we explore the terrestrial aridity responses to anthropogenic black carbon (BC) and sulfate (SO4) aerosols with Community Earth System Model simulations. Positive BC radiative forcing decreases precipitation averaged over global land at a rate of 0.9%/°C of global mean surface temperature increase (moderate drying), while BC radiative forcing increases PET by 1.0%/°C (also drying). BC leads to a global decrease of 1.9%/°C in AI (drying). SO4 forcing is negative and causes precipitation a decrease at a rate of 6.7%/°C cooling (strong drying). PET also decreases in response to SO4 aerosol cooling by 6.3%/°C cooling (contributing to moistening). Thus, SO4 cooling leads to a small decrease in AI (drying) by 0.4%/°C cooling. Despite the opposite effects on global mean temperature, BC and SO4 both contribute to the twentieth century drying (AI decrease). Sensitivity test indicates that surface temperature and surface available energy changes dominate BC- and SO4-induced PET changes.

Climate change and habitat fragmentation drive the occurrence of Borrelia burgdorferi, the agent of Lyme disease, at the northeastern limit of its distribution

PubMed Central

Simon, Julie A; Marrotte, Robby R; Desrosiers, Nathalie; Fiset, Jessica; Gaitan, Jorge; Gonzalez, Andrew; Koffi, Jules K; Lapointe, Francois-Joseph; Leighton, Patrick A; Lindsay, Lindsay R; Logan, Travis; Milord, Francois; Ogden, Nicholas H; Rogic, Anita; Roy-Dufresne, Emilie; Suter, Daniel; Tessier, Nathalie; Millien, Virginie

2014-01-01

Lyme borreliosis is rapidly emerging in Canada, and climate change is likely a key driver of the northern spread of the disease in North America. We used field and modeling approaches to predict the risk of occurrence of Borrelia burgdorferi, the bacteria causing Lyme disease in North America. We combined climatic and landscape variables to model the current and future (2050) potential distribution of the black-legged tick and the white-footed mouse at the northeastern range limit of Lyme disease and estimated a risk index for B. burgdorferi from these distributions. The risk index was mostly constrained by the distribution of the white-footed mouse, driven by winter climatic conditions. The next factor contributing to the risk index was the distribution of the black-legged tick, estimated from the temperature. Landscape variables such as forest habitat and connectivity contributed little to the risk index. We predict a further northern expansion of B. burgdorferi of approximately 250–500 km by 2050 – a rate of 3.5–11 km per year – and identify areas of rapid rise in the risk of occurrence of B. burgdorferi. Our results will improve understanding of the spread of Lyme disease and inform management strategies at the most northern limit of its distribution. PMID:25469157

Comprehensive Lipidome-Wide Profiling Reveals Dynamic Changes of Tea Lipids during Manufacturing Process of Black Tea.

PubMed

Li, Jia; Hua, Jinjie; Zhou, Qinghua; Dong, Chunwang; Wang, Jinjin; Deng, Yuliang; Yuan, Haibo; Jiang, Yongwen

2017-11-22

As important biomolecules in Camellia sinensis L., lipids undergo substantial changes during black tea manufacture, which is considered to contribute to tea sensory quality. However, limited by analytical capacity, detailed lipid composition and its dynamic changes during black tea manufacture remain unclear. Herein, we performed tea lipidome profiling using high resolution liquid chromatography coupled to mass spectrometry (LC-MS), which allows simultaneous and robust analysis of 192 individual lipid species in black tea, covering 17 (sub)classes. Furthermore, dynamic changes of tea lipids during black tea manufacture were investigated. Significant alterations of lipid pattern were revealed, involved with chlorophyll degradation, metabolic pathways of glycoglycerolipids, and other extraplastidial membrane lipids. To our knowledge, this report presented most comprehensive coverage of lipid species in black tea. This study provides a global and in-depth metabolic map of tea lipidome during black tea manufacture.

A Data-Driven Simulation of HIV Spread Among Young Men Who Have Sex With Men: Role of Age and Race Mixing and STIs.

PubMed

Beck, Ekkehard C; Birkett, Michelle; Armbruster, Benjamin; Mustanski, Brian

2015-10-01

Young men who have sex with men (YMSM) in the United States have a high HIV incidence with substantial racial disparities that are poorly understood. We use a data-driven simulation model to understand the impact of network-level mechanisms and sexually transmitted infections on the spread of HIV among YMSM. We designed and parameterized a stochastic agent-based network simulation model using results of a longitudinal cohort study of YMSM in Chicago. Within this model, YMSM formed and dissolved partnerships over time, and partnership types were stratified by length of partnership, sex, and age of the partner. In each partnership, HIV, gonorrhea, and chlamydia could be transmitted. Counterfactual scenarios were run to examine drivers of HIV. Over a 15-year simulation, the HIV epidemic among YMSM continued to rise, with Latino/white YMSM facing a steeper increase in the HIV burden compared with black YMSM. YMSM in partnerships with older MSM, in particular black YMSM with older black MSM, were at highest risk for HIV, and 1 infection prevented with an older partner would prevent 0.8 additional infections among YMSM. Additionally, racial disparities in HIV were driven by differences in the HIV prevalence of YMSM partners. Finally, of all HIV infections among YMSM, 14.6% were attributable to NG and CT infections. Network-level mechanisms and sexually transmitted infections play a significant role in the spread of HIV and in racial disparities among YMSM. HIV prevention efforts should target YMSM across race, and interventions focusing on YMSM partnerships with older MSM might be highly effective.

A data-driven simulation of HIV spread among young men who have sex with men: the role of age and race mixing, and STIs

PubMed Central

BECK, Ekkehard C.; BIRKETT, Michelle; ARMBRUSTER, Benjamin; MUSTANSKI, Brian

2015-01-01

Objective Young men who have sex with men (YMSM) in the U.S. have a high HIV incidence with substantial racial disparities that are poorly understood. We use a data-driven simulation model to understand the impact of network-level mechanisms and STI infections on the spread of HIV among YMSM. Methods We designed and parameterized a stochastic agent-based network simulation model using results of a longitudinal cohort study of YMSM in Chicago. Within this model, YMSM formed and dissolved partnerships over time, and partnership-types were stratified by length of partnership, sex and age of the partner. In each partnership, HIV, gonorrhea and chlamydia could be transmitted. Counterfactual scenarios were run to examine drivers of HIV. Results Over a 15 year simulation, the HIV epidemic among YMSM continued to rise with Latino/White YMSM facing a steeper increase in the HIV burden compared to Black YMSM. YMSM in partnerships with older MSM, in particular Black YMSM with older Black MSM, were at highest risk for HIV and one infection prevented with an older partner would prevent 0.8 additional infections among YMSM. Additionally, racial disparities in HIV were driven by differences in the HIV prevalence of YMSM partners. Finally, of all HIV infections among YMSM, 14.6% were attributable to NG and CT infections. Conclusion Network-level mechanisms and STI infections play a significant role in the spread of HIV, and in racial disparities among YMSM. HIV prevention efforts should target YMSM across race, and interventions focusing on YMSM partnerships with older MSM might be highly effective. PMID:26102448

Predicting sea-level rise vulnerability of terrestrial habitat and wildlife of the Northwestern Hawaiian Islands

USGS Publications Warehouse

Reynolds, Michelle H.; Berkowitz, Paul; Courtot, Karen N.; Krause, Crystal M.; Reynolds, Michelle H.; Berkowitz, Paul; Courtot, Karen N.; Krause, Crystal M.

2012-01-01

If current climate change trends continue, rising sea levels may inundate low-lying islands across the globe, placing island biodiversity at risk. Recent models predict a rise of approximately one meter (1 m) in global sea level by 2100, with larger increases possible in areas of the Pacific Ocean. Pacific Islands are unique ecosystems home to many endangered endemic plant and animal species. The Northwestern Hawaiian Islands (NWHI), which extend 1,930 kilometers (km) beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahanaumokuakea Marine National Monument. These NWHI support the largest tropical seabird rookery in the world, providing breeding habitat for 21 species of seabirds, 4 endemic land bird species and essential foraging, breeding, or haul-out habitat for other resident and migratory wildlife. In recent years, concern has grown about the increasing vulnerability of the NWHI and their wildlife populations to changing climatic patterns, particularly the uncertainty associated with potential impacts from global sea-level rise (SLR) and storms. In response to the need by managers to adapt future resource protection strategies to climate change variability and dynamic island ecosystems, we have synthesized and down scaled analyses for this important region. This report describes a 2-year study of a remote northwestern Pacific atoll ecosystem and identifies wildlife and habitat vulnerable to rising sea levels and changing climate conditions. A lack of high-resolution topographic data for low-lying islands of the NWHI had previously precluded an extensive quantitative model of the potential impacts of SLR on wildlife habitat. The first chapter (chapter 1) describes the vegetation and topography of 20 islands of Papahanaumokuakea Marine National Monument, the distribution and status of wildlife populations, and the predicted impacts for a range of SLR scenarios. Furthermore, this chapter explores the potential effects of SLR on wildlife breeding habitats for each island. The subsequent chapter (chapter 2) details a study of the Laysan Island ecosystem, describing a quantitative model that incorporates SLR, storm wave, and rising groundwater inundation. Wildlife, storm, and oceanographic data allowed for an assessment of the phenological and spatial vulnerability of Laysan Island's breeding bird species to SLR and storms. Using remote sensing and geospatial techniques, we estimated topography, classified vegetation, modeled SLR, and evaluated a range of climate change scenarios. On the basis of high-resolution airborne data collected during 2010-11 (root-mean-squared error = 0.05-0.18 m), we estimated the maximum elevation of 20 individual islands extending from Kure Atoll to French Frigate Shoals (range: 1.8-39.7 m) and computed the mean elevation (1.7 m, standard deviation 1.1 m) across all low-lying islands. We also analyzed general climate models to describe rainfall and temperature scenarios expected to influence adaptation of some plants and animals for this region. Outcomes for the NWHI predicted an increase in temperature of 1.8-2.6 degrees Celsius (°C) and an annual decrease in precipitation of 24.7-76.3 millimeters (mm) across the NWHI by 2100. Our models of passive SLR (excluding wave-driven effects, erosion, and accretion) showed that approximately 4 percent of the total land area in the NWHI will be lost with scenarios of +1.0 m of SLR and 26 percent will be lost with +2.0 m of SLR. Some atolls are especially vulnerable to SLR. For example, at Pearl and Hermes Atoll our analysis indicated substantial habitat losses with 43 percent of the land area inundated at +1.0 m SLR and 92 percent inundated at +2.0 m SLR. Across the NWHI, seven islands will be completely submerged with +2.0 m SLR. The limited global ranges of some tropical nesting birds make them particularly vulnerable to climate change impacts in the NWHI. Climate change scenarios and potential SLR impacts presented here emphasize the need for early climate change adaptation and mitigation planning, especially for species with limited breeding distributions and/or ranges restricted primarily to the low-lying NWHI: Cyperus pennatiformis var. bryanii, Black-footed Albatross (Phoebastria nigripes), Laysan Albatross (P. immutabilis), Bonin Petrel (Pterodroma hypoleuca), Gray-backed Tern (Onychoprion lunatus), Laysan Teal (Anas laysanensis), Laysan Finch (Telespiza cantans), and Hawaiian monk seal (Monachus schauinslandi). Furthermore, SLR scenarios that include the effects of wave dynamics and groundwater rise may indicate amplified vulnerability to climate change driven habitat loss on low-lying islands. In chapter 2, we incorporated the combined effects of SLR, dynamic wave-driven inundation, and rising groundwater in a quantitative study specifically for the Laysan Island ecosystem. This is the first hydrodynamic model to simulate the combined impacts of SLR and wave-driven inundation in the NWHI. We developed a high-resolution digital elevation model (mean vertical accuracy of 0.32 m) for the island. Then using recent satellite imagery, geospatial models, and historical oceanographic, storm, and biological data we estimated potential inundation extent, habitat loss, and wildlife population impacts for a range of potential SLR scenarios (0.00, +0.50, +1.00, +1.50, and +2.00 m) that may occur over the next century. Additionally, we estimated the carrying capacity of Laysan Island for five species based on the available population monitoring data and described how potential losses in nesting habitat could influence population dynamics for Black-footed Albatross, Laysan Albatross, Red-footed Booby (Sula sula), Laysan Teal, and Laysan Finch. For some other seabird populations (Masked Booby, S. dactylatra; Brown Booby, S. leucogaster; Great Frigatebird, Fregata minor; and Sooty Tern, Onychoprion fuscata), we used recent colony distribution data, land cover maps, and nesting behavior to estimate potential losses of nesting habitat from SLR and wave-driven inundation. We observed far greater potential impacts of SLR to wildlife with the dynamic wave-driven modeling approach than with the passive modeling approach. Depending on SLR scenario and coastal orientation, during storms under a +2.00 m SLR scenario, the wave-driven inundation model predicted three times more inundation than the passive model (17.2 percent of total terrestrial area versus 4.6 percent, respectively). Large-wave events generally added 1 m of water height to passive inundation surfaces, therefore our dynamic models (during storm events) forecasted comparable inundation extents earlier than passive models. Although wave-driven water levels were highest in the northwest quadrant of Laysan Island, the greatest extent of inundation occurred in the southeast where coastal dunes less than 3 m above mean sea level provide little protection from wave-driven inundation. When wave-driven inundation was included in the SLR model for Laysan Island greater nesting habitat loss and potential impacts on wildlife population dynamics were predicted. The consequences of habitat loss due to SLR may be worse for species with colonies in the wave-exposed coastal zones (for example, Black-footed Albatross) and for populations already near the island's carrying capacity (for example, Laysan Teal). Species whose peak incubation and chick-rearing periods coincide with seasonally high wave heights also will be increasingly vulnerable, especially those species nesting on the ground in areas vulnerable to inundation, such as Gray-backed Tern and Black-footed Albatross. Other species that have space for population growth, or are not restricted to a narrow range of habitat types on Laysan (for instance, Sooty Terns), may be less sensitive to habitat loss from SLR over the next century. Our assessments of inundation risk, habitat loss, and wildlife species vulnerability synthesize current knowledge about individual islands and contribute to a broader understanding of the impacts of inundation from SLR and storm-induced waves. Yet, most NWHI and their bird populations lack monitoring data to evaluate adaptations to and impacts of climate change. Exceptions include some data sets from long-term monitoring of wildlife populations, tides, or weather at French Frigate Shoals, Laysan Island, and Midway Atoll. These data sets are potentially valuable baselines, which could be informative for adaptive learning (integrating management and science) to predict, adapt, and mitigate the effects of climate change on NWHI wildlife in the future. This study provides the first quantitative vulnerability assessment for all of the low-lying NWHI, and results identify biological communities, locales, and resident endangered species of Papahanaumokuakea Marine National Monument expected to be at risk from SLR. This report is also intended as a reference for managers and conservation planners, a tool to identify and potentially reduce uncertainty, and a starting place for developing climate change monitoring priorities and future scientific studies.

Role of Climate Change in Global Predictions of Future Tropospheric Ozone and Aerosols

NASA Technical Reports Server (NTRS)

Liao, Hong; Chen, Wei-Ting; Seinfeld, John H.

2006-01-01

A unified tropospheric chemistry-aerosol model within the Goddard Institute for Space Studies general circulation model II is applied to simulate an equilibrium CO2-forced climate in the year 2100 to examine the effects of climate change on global distributions of tropospheric ozone and sulfate, nitrate, ammonium, black carbon, primary organic carbon, secondary organic carbon, sea salt, and mineral dust aerosols. The year 2100 CO2 concentration as well as the anthropogenic emissions of ozone precursors and aerosols/aerosol precursors are based on the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (SRES) A2. Year 2100 global O3 and aerosol burdens predicted with changes in both climate and emissions are generally 5-20% lower than those simulated with changes in emissions alone; as exceptions, the nitrate burden is 38% lower, and the secondary organic aerosol burden is 17% higher. Although the CO2-driven climate change alone is predicted to reduce the global O3 concentrations over or near populated and biomass burning areas because of slower transport, enhanced biogenic hydrocarbon emissions, decomposition of peroxyacetyl nitrate at higher temperatures, and the increase of O3 production by increased water vapor at high NOx levels. The warmer climate influences aerosol burdens by increasing aerosol wet deposition, altering climate-sensitive emissions, and shifting aerosol thermodynamic equilibrium. Climate change affects the estimates of the year 2100 direct radiative forcing as a result of the climate-induced changes in burdens and different climatological conditions; with full gas-aerosol coupling and accounting for ozone and direct radiative forcings by the O2, sulfate, nitrate, black carbon, and organic carbon are predicted to be +0.93, -0.72, -1.0, +1.26, and -0.56 W m(exp -2), respectively, using present-day climate and year 2100 emissions, while they are predicted to be +0.76, -0.72, 0.74, +0.97, and -0.58 W m(exp -2), respectively, with year 2100 climate and emissions.

Light in Thermal Environments (LITE) Workshop

NASA Technical Reports Server (NTRS)

1993-01-01

Light emitted from high temperature black smokers (350 C) at mid-ocean ridge spreading centers has been documented, but the source of this light and its photochemical and biological consequences have yet to be investigated. Preliminary studies indicate that thermal radiation alone might account for the 'glow' and that a novel photoreceptor in shrimp colonizing black smoker chimneys may detect this 'glow.' A more controversial question is whether there may be sufficient photon flux of appropriate wavelengths to support geothermally-driven photosynthesis (GDP) by microorganisms. Although only a very low level of visible and near infrared light may be emitted from any single hydrothermal vent, several aspects of the light make it of more than enigmatic interest. First, the light is clearly linked to geophysical (and perhaps geochemical) processes; its attributes may serve as powerful index parameters for monitoring change in these processes. Second, while the glow at a vent orifice is a very local phenomenon, more expansive subsurface environments may be illuminated, thereby increasing the spatial scale at which biological consequences of this light might be considered. Third, in contrast to intermittent bioluminescent light sources in the deep sea, the light emitted at vents almost certainly glows or flickers continuously over the life of the individual black smokers (years to decades); collectively, light emitted from black smokers along the ocean's spreading centers superimposed on background Cerenkov radiation negates the concept of the deep sea as an environment devoid of abiotic light. Finally, the history of hydrothermal activity predates the origin of life; light in the deep sea has been a continuous phenomenon on a geological time scale and may have served either as a seed or refugium for the evolution of biological photochemical reactions or adaptations.

Climate-driven introduction of the Black Death and successive plague reintroductions into Europe.

PubMed

Schmid, Boris V; Büntgen, Ulf; Easterday, W Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr

2015-03-10

The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe.

Climate-driven introduction of the Black Death and successive plague reintroductions into Europe

PubMed Central

Büntgen, Ulf; Easterday, W. Ryan; Ginzler, Christian; Walløe, Lars; Bramanti, Barbara; Stenseth, Nils Chr.

2015-01-01

The Black Death, originating in Asia, arrived in the Mediterranean harbors of Europe in 1347 CE, via the land and sea trade routes of the ancient Silk Road system. This epidemic marked the start of the second plague pandemic, which lasted in Europe until the early 19th century. This pandemic is generally understood as the consequence of a singular introduction of Yersinia pestis, after which the disease established itself in European rodents over four centuries. To locate these putative plague reservoirs, we studied the climate fluctuations that preceded regional plague epidemics, based on a dataset of 7,711 georeferenced historical plague outbreaks and 15 annually resolved tree-ring records from Europe and Asia. We provide evidence for repeated climate-driven reintroductions of the bacterium into European harbors from reservoirs in Asia, with a delay of 15 ± 1 y. Our analysis finds no support for the existence of permanent plague reservoirs in medieval Europe. PMID:25713390

Negative impacts of high temperatures on growth of black spruce forests intensify with the anticipated climate warming.

PubMed

Girardin, Martin P; Hogg, Edward H; Bernier, Pierre Y; Kurz, Werner A; Guo, Xiao Jing; Cyr, Guillaume

2016-02-01

An increasing number of studies conclude that water limitations and heat stress may hinder the capacity of black spruce (Picea mariana (Mill.) B.S.P.) trees, a dominant species of Canada's boreal forests, to grow and assimilate atmospheric carbon. However, there is currently no scientific consensus on the future of these forests over the next century in the context of widespread climate warming. The large spatial extent of black spruce forests across the Canadian boreal forest and associated variability in climate, demography, and site conditions pose challenges for projecting future climate change responses. Here we provide an evaluation of the impacts of climate warming and drying, as well as increasing [CO2 ], on the aboveground productivity of black spruce forests across Canada south of 60°N for the period 1971 to 2100. We use a new extensive network of tree-ring data obtained from Canada's National Forest Inventory, spatially explicit simulations of net primary productivity (NPP) and its drivers, and multivariate statistical modeling. We found that soil water availability is a significant driver of black spruce interannual variability in productivity across broad areas of the western to eastern Canadian boreal forest. Interannual variability in productivity was also found to be driven by autotrophic respiration in the warmest regions. In most regions, the impacts of soil water availability and respiration on interannual variability in productivity occurred during the phase of carbohydrate accumulation the year preceding tree-ring formation. Results from projections suggest an increase in the importance of soil water availability and respiration as limiting factors on NPP over the next century due to warming, but this response may vary to the extent that other factors such as carbon dioxide fertilization, and respiration acclimation to high temperature, contribute to dampening these limitations. © 2015 Her Majesty the Queen in Right of Canada. Reproduced with the permission of the Minister of Natural Resources Canada.

Two classes of volcanic plumes on Io

USGS Publications Warehouse

McEwen, A.S.; Soderblom, L.A.

1983-01-01

Comparison of Voyager 1 and Voyager 2 images of the south polar region of Io has revealed that a major volcanic eruption occured there during the period between the two spacecraft encounters. An annular deposit ???1400 km in diameter formed around the Aten Patera caldera (311??W, 48??S), the floor of which changed from orange to red-black. The characteristics of this eruption are remarkably similar to those described earlier for an eruption centered on Surt caldera (338??W, 45??N) that occured during the same period, also at high latitude, but in the north. Both volcanic centers were evidently inactive during the Voyager 1 and 2 encounters but were active sometime between the two. The geometric and colorimetric characteristics, as well as scale of the two annular deposits, are virtually identical; both resemble the surface features formed by the eruption of Pele (255??W, 18??S). These three very large plume eruptions suggest a class of eruption distinct from that of six smaller plumes observed to be continously active by both Voyagers 1 and 2. The smaller plumes, of which Prometheus is the type example, are longer-lived, deposit bright, whitish material, erupt at velocities of ???0.5 km sec-1, and are concentrated at low latitudes in an equatorial belt around the satellite. The very large Pele-type plumes, on the other hand, are relatively short-lived, deposit darker red materials, erupt at ???1.0 km sec-1, and (rather than restricted to a latitudinal band) are restricted in longitude from 240?? to 360??W. Both direct thermal infrared temperature measurements and the implied color temperatures for quenched liquid sulfur suggest that hot spot temperatures of ???650??K are associated with the large plumes and temperatures 650??K), sulfur is a low-viscosity fluid (orange and black, respectively); at other temperatures it is either solid or has a high viscosity. As a result, there will be two zones in Io's crust in which liquid sulfur will flow freely: a shallow zone of orange sulfur and a deeper zone of black sulfur. A low-temperature system driven by SO2 heated to 400 to 400??K by the orange sulfur zone seems the best model for the small plumes; a system driven by sulfur heated to >650??K by hot or even molten silicates in the black sulfur zone seems the best explanation for the large plume class. The large Pele-type plumes are apparently concentrated in a region of the satellite in which a thinner sulfur-rich crust overlies the tidally heated silicate lithosphere, so the black sulfur zone may be fairly shallow in this region. The Prometheus-type plumes are possibly confined to the equatorial belt by some process that concentrates SO2 fluid in the equatorial crust. ?? 1983.

Australian black field crickets show changes in neural gene expression associated with socially-induced morphological, life-history, and behavioral plasticity.

PubMed

Kasumovic, Michael M; Chen, Zhiliang; Wilkins, Marc R

2016-10-24

Ecological and evolutionary model organisms have provided extensive insight into the ecological triggers, adaptive benefits, and evolution of life-history driven developmental plasticity. Despite this, we still have a poor understanding of the underlying genetic changes that occur during shifts towards different developmental trajectories. The goal of this study is to determine whether we can identify underlying gene expression patterns that can describe the different life-history trajectories individuals follow in response to social cues of competition. To do this, we use the Australian black field cricket (Teleogryllus commodus), a species with sex-specific developmental trajectories moderated by the density and quality of calls heard during immaturity. In this study, we manipulated the social information males and females could hear by rearing individuals in either calling or silent treatments. We next used RNA-Seq to develop a reference transcriptome to study changes in brain gene expression at two points prior to sexual maturation. We show accelerated development in both sexes when exposed to calling; changes were also seen in growth, lifespan, and reproductive effort. Functional relationships between genes and phenotypes were apparent from ontological enrichment analysis. We demonstrate that increased investment towards traits such as growth and reproductive effort were often associated with the expression of a greater number of genes with similar effect, thus providing a suite of candidate genes for future research in this and other invertebrate organisms. Our results provide interesting insight into the genomic underpinnings of developmental plasticity and highlight the potential of a genomic exploration of other evolutionary theories such as condition dependence and sex-specific developmental strategies.

Americans misperceive racial economic equality.

PubMed

Kraus, Michael W; Rucker, Julian M; Richeson, Jennifer A

2017-09-26

The present research documents the widespread misperception of race-based economic equality in the United States. Across four studies ( n = 1,377) sampling White and Black Americans from the top and bottom of the national income distribution, participants overestimated progress toward Black-White economic equality, largely driven by estimates of greater current equality than actually exists according to national statistics. Overestimates of current levels of racial economic equality, on average, outstripped reality by roughly 25% and were predicted by greater belief in a just world and social network racial diversity (among Black participants). Whereas high-income White respondents tended to overestimate racial economic equality in the past, Black respondents, on average, underestimated the degree of past racial economic equality. Two follow-up experiments further revealed that making societal racial discrimination salient increased the accuracy of Whites' estimates of Black-White economic equality, whereas encouraging Whites to anchor their estimates on their own circumstances increased their tendency to overestimate current racial economic equality. Overall, these findings suggest a profound misperception of and unfounded optimism regarding societal race-based economic equality-a misperception that is likely to have any number of important policy implications.

Multi-epoch analysis of the X-ray spectrum of the active galactic nucleus in NGC 5506

NASA Astrophysics Data System (ADS)

Sun, Shangyu; Guainazzi, Matteo; Ni, Qingling; Wang, Jingchun; Qian, Chenyang; Shi, Fangzheng; Wang, Yu; Bambi, Cosimo

2018-05-01

We present a multi-epoch X-ray spectroscopy analysis of the nearby narrow-line Seyfert I galaxy NGC 5506. For the first time, spectra taken by Chandra, XMM-Newton, Suzaku, and NuSTAR - covering the 2000-2014 time span - are analyzed simultaneously, using state-of-the-art models to describe reprocessing of the primary continuum by optical thick matter in the AGN environment. The main goal of our study is determining the spin of the supermassive black hole (SMBH). The nuclear X-ray spectrum is photoelectrically absorbed by matter with column density ≃ 3 × 1022 cm-2. A soft excess is present at energies lower than the photoelectric cut-off. Both photo-ionized and collisionally ionized components are required to fit it. This component is constant over the time-scales probed by our data. The spectrum at energies higher than 2 keV is variable. We propose that its evolution could be driven by flux-dependent changes in the geometry of the innermost regions of the accretion disk. The black hole spin in NGC ,5506 is constrained to be 0.93± _{ 0.04 }^{0.04} at 90% confidence level for one interesting parameter.

The Dynamics of Truncated Black Hole Accretion Disks. II. Magnetohydrodynamic Case

NASA Astrophysics Data System (ADS)

Hogg, J. Drew; Reynolds, Christopher S.

2018-02-01

We study a truncated accretion disk using a well-resolved, semi-global magnetohydrodynamic simulation that is evolved for many dynamical times (6096 inner disk orbits). The spectral properties of hard-state black hole binary systems and low-luminosity active galactic nuclei are regularly attributed to truncated accretion disks, but a detailed understanding of the flow dynamics is lacking. In these systems the truncation is expected to arise through thermal instability driven by sharp changes in the radiative efficiency. We emulate this behavior using a simple bistable cooling function with efficient and inefficient branches. The accretion flow takes on an arrangement where a “transition zone” exists in between hot gas in the innermost regions and a cold, Shakura & Sunyaev thin disk at larger radii. The thin disk is embedded in an atmosphere of hot gas that is fed by a gentle outflow originating from the transition zone. Despite the presence of hot gas in the inner disk, accretion is efficient. Our analysis focuses on the details of the angular momentum transport, energetics, and magnetic field properties. We find that the magnetic dynamo is suppressed in the hot, truncated inner region of the disk which lowers the effective α-parameter by 65%.

Astrophysics of Super-Massive Black Hole Mergers

NASA Technical Reports Server (NTRS)

Schnittman, Jeremy D.

2013-01-01

We present here an overview of recent work in the subject of astrophysical manifestations of super-massive black hole (SMBH) mergers. This is a field that has been traditionally driven by theoretical work, but in recent years has also generated a great deal of interest and excitement in the observational astronomy community. In particular, the electromagnetic (EM) counterparts to SMBH mergers provide the means to detect and characterize these highly energetic events at cosmological distances, even in the absence of a space-based gravitational-wave observatory. In addition to providing a mechanism for observing SMBH mergers, EM counterparts also give important information about the environments in which these remarkable events take place, thus teaching us about the mechanisms through which galaxies form and evolve symbiotically with their central black holes.

DISCOVERY OF A PSEUDOBULGE GALAXY LAUNCHING POWERFUL RELATIVISTIC JETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kotilainen, Jari K.; Olguín-Iglesias, Alejandro; León-Tavares, Jonathan

Supermassive black holes launching plasma jets at close to the speed of light, producing gamma-rays, have ubiquitously been found to be hosted by massive elliptical galaxies. Since elliptical galaxies are generally believed to be built through galaxy mergers, active galactic nuclei (AGN) launching relativistic jets are associated with the latest stages of galaxy evolution. We have discovered a pseudobulge morphology in the host galaxy of the gamma-ray AGN PKS 2004-447. This is the first gamma-ray emitter radio-loud AGN found to have been launched from a system where both the black hole and host galaxy have been actively growing via secularmore » processes. This is evidence of an alternative black hole–galaxy co-evolutionary path to develop powerful relativistic jets, which is not merger driven.« less

Taking the Pulse of a Black Hole System

NASA Astrophysics Data System (ADS)

2011-01-01

Using two NASA X-ray satellites, astronomers have discovered what drives the "heartbeats" seen in the light from an unusual black hole system. These results give new insight into the ways that black holes can regulate their intake and severely curtail their growth. This study examined GRS 1915+105 (GRS 1915 for short), a binary system in the Milky Way galaxy containing a black hole about 14 times more massive than the Sun that is feeding off material from a companion star. As this material falls towards the black hole, it forms a swirling disk that emits X-rays. The black hole in GRS 1915 has been estimated to rotate at the maximum possible rate, allowing material in the inner disk to orbit very close to the black hole, at a radius only 20% larger than the event horizon, where the material travels at 50% the speed of light. Using the Chandra X-ray Observatory and the Rossi X-ray Timing Explorer (RXTE), researchers monitored this black hole system over a period of eight hours. As they watched, GRS 1915 gave off a short, bright pulse of X-ray light approximately every 50 seconds, varying in brightness by a factor of about three. This type of rhythmic cycle closely resembles an electrocardiogram of a human heart -- though at a slower pace. "Trying to understand the physics of this 'heartbeat state' is a little like trying to understand how a person's heart beats by watching changes in the blood flow through their veins," said Joey Neilsen, a graduate student at Harvard University, who presented these results from his dissertation at the American Astronomical Society (AAS) meeting in Seattle, Wash. It was previously known that GRS 1915 can develop such heartbeats when its mass consumption rate is very high. After monitoring it with the special combination of Chandra and RXTE, Neilsen and his collaborators realized that they could use the pulses to figure out what controls how much material the black hole consumes. "With each beat, the black hole pumps an enormous amount of energy into its surroundings," said Neilsen. "All that energy has profound consequences for the disk, even very far from the black hole." Changes in the X-ray spectrum observed by RXTE during each heartbeat reveal that the inner region of the disk, at only a few times the radius of the black hole's event horizon, emits enough radiation to push material away from the black hole. Eventually the disk gets so bright and so hot that it essentially disintegrates and plunges towards the black hole. Then the cycle begins again. "This behavior is a clear and startling demonstration of the power of radiation in the fight against gravity," said co-author Ron Remillard of the Massachusetts Institute of Technology. "During the heartbeat state, radiation prevents the black hole from ingesting as much material as it would otherwise." Neilsen and his colleagues estimated that the rate at which material falls onto the black hole changes by about a factor of ten during each cycle, with the maximum rate coinciding with the X-ray pulse. Between pulses, the inner part of the disk refills from material farther away from the black hole. The astronomers also used Chandra's high-resolution spectrograph to study the effects of this heartbeat variation on regions of the disk very far from the black hole, at distances of about 100,000 to a million times the radius of the event horizon. By analyzing the Chandra spectrum, they found a very strong wind being driven away from the outer parts of the disk. The wind changed significantly in just 5 seconds, nearly 100 times faster than has ever been seen in a wind from a stellar-mass black hole. The researchers concluded that the strong X-ray pulse from the inner disk must heat the outer disk. This heating process launches a wind, so that each new pulse drives more wind from the disk. The rate of mass expelled in this wind is remarkably high, as much as 25 times the maximum rate at which matter falls onto the black hole. "All that energy blows away an enormous amount of matter, equivalent to one third the mass of the Moon per day! This effectively forces the black hole onto a severe diet, and we think it eventually has real consequences for the system's heartbeat," said co-author Julia Lee, associate professor in the Astronomy department at Harvard and Neilsen's thesis advisor. This massive wind drains material from the outer disk and after a couple weeks, this depletion affects the inner disk, causing the black hole to feed much more slowly and its X-ray brightness to decrease substantially. Unable to power such strong variations in the disk and the wind, GRS 1915's 'heart' ceases to beat. This remarkable system then likely begins one of its 13 other known patterns of variation. Neilsen is a winner of the Roger Doxsey Travel Prize, which provides graduate students within one year of receiving or receipt of their PhD a monetary prize to enable the oral presentation of their dissertation research at an AAS meeting. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. More information, including images and other multimedia, can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

An analysis of the changes on intermediate products during the thermal processing of black garlic.

PubMed

Yuan, Heng; Sun, Linjuan; Chen, Min; Wang, Jun

2018-01-15

The thermal processing of black garlic was simulated. Fresh garlic was incubated at 55°C with 80% humidity and sampled every 5 or 10days. The changes in relevant products were as follows: the fructan content was decreased by 84.79%, and the fructose content was increased by 508.11%. The contents of Maillard reaction intermediate products were first increased and then decreased. The colour of garlic gradually became dark and the pH decreased from 6.13 to 4.00. By analyzing these changes, the mechanism of black garlic formation and the changes on the Maillard reaction were revealed. The sweetness of black garlic resulted mainly from the fructose that was produced, and the black colour was largely due to the Maillard reaction between fructose/glucose and amino acids. An understanding of this process is useful to explain the formation mechanism of black garlic and could lead to better control of the quality of black garlic. Copyright © 2017 Elsevier Ltd. All rights reserved.

Implicit and Explicit Racial Attitudes Changed During Black Lives Matter.

PubMed

Sawyer, Jeremy; Gampa, Anup

2018-07-01

Lab-based interventions have been ineffective in changing individuals' implicit racial attitudes for more than brief durations, and exposure to high-status Black exemplars like Obama has proven ineffective in shifting societal-level racial attitudes. Antiracist social movements, however, offer a potential societal-level alternative for reducing racial bias. Racial attitudes were examined before and during Black Lives Matter (BLM) and its high points of struggle with 1,369,204 participants from 2009 to 2016. After controlling for changes in participant demographics, overall implicit attitudes were less pro-White during BLM than pre-BLM, became increasingly less pro-White across BLM, and were less pro-White during most periods of high BLM struggle. Considering changes in implicit attitudes by participant race, Whites became less implicitly pro-White during BLM, whereas Blacks showed little change. Regarding explicit attitudes, Whites became less pro-White and Blacks became less pro-Black during BLM, each moving toward an egalitarian "no preference" position.

The Afro-American Work/Family Nexus: An Exploratory Analysis.

ERIC Educational Resources Information Center

Collins, Patricia Hill

1986-01-01

Sketches out a framework linking black labor market trends in the post World War II era to actual and potential changes in black family patterns. Summarizes selected scholarship and then provides a gender-specific analysis of the changing employment status of black Americans. Urgres that links be made between black family life and the political…

Bringing automatic stereotyping under control: implementation intentions as efficient means of thought control.

PubMed

Stewart, Brandon D; Payne, B Keith

2008-10-01

The evidence for whether intentional control strategies can reduce automatic stereotyping is mixed. Therefore, the authors tested the utility of implementation intentions--specific plans linking a behavioral opportunity to a specific response--in reducing automatic bias. In three experiments, automatic stereotyping was reduced when participants made an intention to think specific counterstereotypical thoughts whenever they encountered a Black individual. The authors used two implicit tasks and process dissociation analysis, which allowed them to separate contributions of automatic and controlled thinking to task performance. Of importance, the reduction in stereotyping was driven by a change in automatic stereotyping and not controlled thinking. This benefit was acquired with little practice and generalized to novel faces. Thus, implementation intentions may be an effective and efficient means for controlling automatic aspects of thought.

Microwavable thermal energy storage material

DOEpatents

Salyer, I.O.

1998-09-08

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

Microwavable thermal energy storage material

DOEpatents

Salyer, Ival O.

1998-09-08

A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

Fuzzy spaces topology change as a possible solution to the black hole information loss paradox

NASA Astrophysics Data System (ADS)

Silva, C. A. S.

2009-06-01

The black hole information loss paradox is one of the most intricate problems in modern theoretical physics. A proposal to solve this is one related with topology change. However it has found some obstacles related to unitarity and cluster decomposition (locality). In this Letter we argue that modelling the black hole's event horizon as a noncommutative manifold - the fuzzy sphere - we can solve the problems with topology change, getting a possible solution to the black hole information loss paradox.

Cytotoxic T lymphocyte-dependent tumor growth inhibition by a vascular endothelial growth factor-superantigen conjugate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Qingwen; State Key Laboratory of Genetic Engineering, Fudan University, Shanghai 200433; Jiang, Songmin

2012-11-02

Highlights: Black-Right-Pointing-Pointer We construct and purify a fusion protein VEGF-SEA. Black-Right-Pointing-Pointer VEGF-SEA strongly repressed the growth of murine solid sarcoma 180 (S180) tumors. Black-Right-Pointing-Pointer T cells driven by VEGF-SEA were accumulated around tumor cells bearing VEGFR by mice image model. Black-Right-Pointing-Pointer VEGF-SEA can serve as a tumor targeting agent and sequester CTLs into the tumor site. Black-Right-Pointing-Pointer The induced CTLs could release the cytokines, perforins and granzyme B to kill the tumor cells. -- Abstract: T cells are major lymphocytes in the blood and passengers across the tumor vasculature. If these T cells are retained in the tumor site, amore » therapeutic potential will be gained by turning them into tumor-reactive cytotoxic T lymphocytes (CTLs). A fusion protein composed of human vascular endothelial growth factor (VEGF) and staphylococcal enterotoxin A (SEA) with a D227A mutation strongly repressed the growth of murine solid sarcoma 180 (S180) tumors (control versus VEGF-SEA treated with 15 {mu}g, mean tumor weight: 1.128 g versus 0.252 g, difference = 0.876 g). CD4{sup +} and CD8{sup +} T cells driven by VEGF-SEA were accumulated around VEGFR expressing tumor cells and the induced CTLs could release the tumoricidal cytokines, such as interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha). Meanwhile, intratumoral CTLs secreted cytolytic pore-forming perforin and granzyme B proteins around tumor cells, leading to the death of tumor cells. The labeled fusion proteins were gradually targeted to the tumor site in an imaging mice model. These results show that VEGF-SEA can serve as a tumor targeting agent and sequester active infiltrating CTLs into the tumor site to kill tumor cells, and could therefore be a potential therapeutical drug for a variety of cancers.« less

The Paradox of Success at a No-Excuses School

ERIC Educational Resources Information Center

Golann, Joanne W.

2015-01-01

No recent reform has had so profound an effect as no-excuses schools in increasing the achievement of low-income black and Hispanic students. In the past decade, no-excuses schools--whose practices include extended instructional time, data-driven instruction, ongoing professional development, and a highly structured disciplinary system--have…

Equilibrium configurations of perfect fluid orbiting Schwarzschild-de Sitter black holes

NASA Astrophysics Data System (ADS)

Stuchlík, Z.; Slaný, P.; Hledík, S.

2000-11-01

The hydrodynamical structure of perfect fluid orbiting Schwarzschild-de Sitter black holes is investigated for configurations with uniform distribution of angular momentum density. It is shown that in the black-hole backgrounds admitting the existence of stable circular geodesics, closed equipotential surfaces with a cusp, allowing the existence of toroidal accretion disks, can exist. Two surfaces with a cusp exist for the angular momentum density smaller than the one corresponding to marginally bound circular geodesics; the equipotential surface corresponding to the marginally bound circular orbit has just two cusps. The outer cusp is located nearby the static radius where the gravitational attraction is compensated by the cosmological repulsion. Therefore, due to the presence of a repulsive cosmological constant, the outflow from thick accretion disks can be driven by the same mechanism as the accretion onto the black hole. Moreover, properties of open equipotential surfaces in vicinity of the axis of rotation suggest a strong collimation effects of the repulsive cosmological constant acting on jets produced by the accretion disks.

Input-driven versus turnover-driven controls of simulated changes in soil carbon due to land-use change

NASA Astrophysics Data System (ADS)

Nyawira, S. S.; Nabel, J. E. M. S.; Brovkin, V.; Pongratz, J.

2017-08-01

Historical changes in soil carbon associated with land-use change (LUC) result mainly from the changes in the quantity of litter inputs to the soil and the turnover of carbon in soils. We use a factor separation technique to assess how the input-driven and turnover-driven controls, as well as their synergies, have contributed to historical changes in soil carbon associated with LUC. We apply this approach to equilibrium simulations of present-day and pre-industrial land use performed using the dynamic global vegetation model JSBACH. Our results show that both the input-driven and turnover-driven changes generally contribute to a gain in soil carbon in afforested regions and a loss in deforested regions. However, in regions where grasslands have been converted to croplands, we find an input-driven loss that is partly offset by a turnover-driven gain, which stems from a decrease in the fire-related carbon losses. Omitting land management through crop and wood harvest substantially reduces the global losses through the input-driven changes. Our study thus suggests that the dominating control of soil carbon losses is via the input-driven changes, which are more directly accessible to human management than the turnover-driven ones.

Growing massive black holes in a Local Group environment: the central supermassive, slowly sinking and ejected populations

NASA Astrophysics Data System (ADS)

Micic, Miroslav; Holley-Bockelmann, Kelly; Sigurdsson, Steinn

2011-06-01

We explore the growth of ≤107 M⊙ black holes that reside at the centres of spiral and field dwarf galaxies in a Local Group type of environment. We use merger trees from a cosmological N-body simulation known as Via Lactea 2 (VL-2) as a framework to test two merger-driven semi-analytic recipes for black hole growth that include dynamical friction, tidal stripping and gravitational wave recoil in over 20 000 merger tree realizations. First, we apply a Fundamental Plane limited (FPL) model to the growth of Sgr A*, which drives the central black hole to a maximum mass limited by the black hole Fundamental Plane after every merger. Next, we present a new model that allows for low-level prolonged gas accretion (PGA) during the merger. We find that both models can generate an Sgr A* mass black hole. We predict a population of massive black holes in local field dwarf galaxies - if the VL-2 simulation is representative of the growth of the Local Group, we predict up to 35 massive black holes (≤106 M⊙) in Local Group field dwarfs. We also predict that hundreds of ≤105 M⊙ black holes fail to merge, and instead populate the Milky Way halo, with the most massive of them at roughly the virial radius. In addition, we find that there may be hundreds of massive black holes ejected from their hosts into the nearby intergalactic medium due to gravitational wave recoil. We discuss how the black hole population in the Local Group field dwarfs may help to constrain the growth mechanism for Sgr A*.

Global Warming in the 21st Century: An Alternate Scenario

NASA Technical Reports Server (NTRS)

Hansen, James E.; Sato, Makiko; Ruedy, Reto; Lacis, Andrew; Oinas, Valdar

2000-01-01

A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven by non-CO2 greenhouse gases (GHGs), such as CFCs, CH4 and N2O, not by the products of fossil fuel burning, CO2 and aerosols, whose positive and negative climate forcings are partially offsetting. The growth rate of non-CO2 GHGs has declined in the past decade. If sources of CH4 and O3 precursors were reduced in the future, the change of climate forcing by non-CO2 GHGs In the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO2 emissions, this could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition-specific longterm global monitoring of aerosol properties.

Luminescence ages for alluvial-fan deposits in Southern Death Valley: Implications for climate-driven sedimentation along a tectonically active mountain front

USGS Publications Warehouse

Sohn, M.F.; Mahan, S.A.; Knott, J.R.; Bowman, D.D.

2007-01-01

Controversy exists over whether alluvial-fan sedimentation along tectonically active mountain fronts is driven by climatic changes or tectonics. Knowing the age of sedimentation is the key to understanding the relationship between sedimentation and its cause. Alluvial-fan deposits in Death Valley and throughout the arid southwestern United States have long been the subjects of study, but their ages have generally eluded researchers until recently. Most mapping efforts have recognized at least four major relative-age groupings (Q1 (oldest), Q2, Q3, and Q4 (youngest)), using observed changes in surface soils and morphology, relation to the drainage net, and development of desert pavement. Obtaining numerical age determinations for these morphologic stages has proven challenging. We report the first optically stimulated luminescence (OSL) ages for three of these four stages deposited within alluvial-fans along the tectonically active Black Mountains of Death Valley. Deposits showing distinct, remnant bar and swale topography (Q3b) have OSL ages from 7 to 4 ka., whereas those with moderate to poorly developed desert pavement and located farther above the active channel (Q3a) have OSL ages from 17 to 11 ka. Geomorphically older deposits with well-developed desert pavement (Q2d) have OSL ages ???25 ka. Using this OSL-based chronology, we note that alluvial-fan deposition along this tectonically active mountain front corresponds to both wet-to-dry and dry-to-wet climate changes recorded globally and regionally. These findings underscore the influence of climate change on alluvial fan deposition in arid and semi-arid regions. ?? 2007 Elsevier Ltd and INQUA.

Staying in the Hood: Black Lesbian and Transgender Women and Identity Management in North Philadelphia.

PubMed

Brooks, Siobhan

2016-12-01

The concept Don't Ask, Don't Tell regarding Black LGBT sexuality in Black communities has been an acceptable form of identity management for Black LGBT people. In other words, Black LGBT people are accepted as long as they are not vocal about their sexuality. However, this is changing with the issue of gay marriage, which is creating a space where Black LGBT people are more open about their gender identity and sexuality in heterosexual Black spaces. This new form of openness allows Black LGBT people to "stay in" their communities, as opposed to coming out. In this article I examine how Black LGBT women in North Philadelphia stay in their communities: being politically active regarding LGBT issues, disengaging from LGBT issues, passing, and educating straight Black people about issues affecting the Black LGBT community. I conclude with implications of staying in and intersectionality among Black heterosexual and LGBT women fighting for social change.

The Crisis in Black and Black.

ERIC Educational Resources Information Center

Hutchinson, Earl Ofari

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

Local biomass burning is a dominant cause of the observed precipitation reduction in southern Africa

PubMed Central

Hodnebrog, Øivind; Myhre, Gunnar; Forster, Piers M.; Sillmann, Jana; Samset, Bjørn H.

2016-01-01

Observations indicate a precipitation decline over large parts of southern Africa since the 1950s. Concurrently, atmospheric concentrations of greenhouse gases and aerosols have increased due to anthropogenic activities. Here we show that local black carbon and organic carbon aerosol emissions from biomass burning activities are a main cause of the observed decline in southern African dry season precipitation over the last century. Near the main biomass burning regions, global and regional modelling indicates precipitation decreases of 20–30%, with large spatial variability. Increasing global CO2 concentrations further contribute to precipitation reductions, somewhat less in magnitude but covering a larger area. Whereas precipitation changes from increased CO2 are driven by large-scale circulation changes, the increase in biomass burning aerosols causes local drying of the atmosphere. This study illustrates that reducing local biomass burning aerosol emissions may be a useful way to mitigate reduced rainfall in the region. PMID:27068129

Modes of occurrence of mercury and other trace elements in coals from the warrior field, Black Warrior Basin, Northwestern Alabama

USGS Publications Warehouse

Diehl, S.F.; Goldhaber, M.B.; Hatch, J.R.

2004-01-01

The mineralogic residence and abundance of trace metals is an important environmental issue. Data from the USGS coal quality database show that potentially toxic elements, including Hg, As, Mo, Se, Cu, and Tl are enriched in a subset of coal samples in the Black Warrior Basin of Alabama, USA. Although the coal as-mined typically is low in these elements, localized enrichments occur in high-pyrite coals and near faults. Microscopic analyses demonstrate that the residence of these elements is dominantly in a late-stage pyrite associated with structurally disrupted coal. Further, our data suggest addition of Hg to the coal matrix as well. The source of these trace elements was hydrothermal fluids driven into the Black Warrior Basin by Alleghanian age tectonism. ?? 2004 Published by Elsevier B.V.

Simulated responses of terrestrial aridity to black carbon and sulfate aerosols

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, L.; Gettelman, A.; Xu, Y.

Aridity index (AI), defined as the ratio of precipitation to potential evapotranspiration (PET), is a measure of the dryness of terrestrial climate. Global climate models generally project future decreases of AI (drying) associated with global warming scenarios driven by increasing greenhouse gas and declining aerosols. Given their different effects in the climate system, scattering and absorbing aerosols may affect AI differently. In this work, we explore the terrestrial aridity responses to anthropogenic black carbon (BC) and sulfate (SO 4) aerosols with Community Earth System Model simulations. Positive BC radiative forcing decreases precipitation averaged over global land at a rate ofmore » 0.9%/°C of global mean surface temperature increase (moderate drying), while BC radiative forcing increases PET by 1.0%/°C (also drying). BC leads to a global decrease of 1.9%/°C in AI (drying). SO 4 forcing is negative and causes precipitation a decrease at a rate of 6.7%/°C cooling (strong drying). PET also decreases in response to SO 4 aerosol cooling by 6.3%/°C cooling (contributing to moistening). Thus, SO 4 cooling leads to a small decrease in AI (drying) by 0.4%/°C cooling. Despite the opposite effects on global mean temperature, BC and SO 4 both contribute to the twentieth century drying (AI decrease). Sensitivity test indicates that surface temperature and surface available energy changes dominate BC- and SO 4-induced PET changes.« less

Simulated responses of terrestrial aridity to black carbon and sulfate aerosols

DOE PAGES

Lin, L.; Gettelman, A.; Xu, Y.; ...

2016-01-27

Aridity index (AI), defined as the ratio of precipitation to potential evapotranspiration (PET), is a measure of the dryness of terrestrial climate. Global climate models generally project future decreases of AI (drying) associated with global warming scenarios driven by increasing greenhouse gas and declining aerosols. Given their different effects in the climate system, scattering and absorbing aerosols may affect AI differently. In this work, we explore the terrestrial aridity responses to anthropogenic black carbon (BC) and sulfate (SO 4) aerosols with Community Earth System Model simulations. Positive BC radiative forcing decreases precipitation averaged over global land at a rate ofmore » 0.9%/°C of global mean surface temperature increase (moderate drying), while BC radiative forcing increases PET by 1.0%/°C (also drying). BC leads to a global decrease of 1.9%/°C in AI (drying). SO 4 forcing is negative and causes precipitation a decrease at a rate of 6.7%/°C cooling (strong drying). PET also decreases in response to SO 4 aerosol cooling by 6.3%/°C cooling (contributing to moistening). Thus, SO 4 cooling leads to a small decrease in AI (drying) by 0.4%/°C cooling. Despite the opposite effects on global mean temperature, BC and SO 4 both contribute to the twentieth century drying (AI decrease). Sensitivity test indicates that surface temperature and surface available energy changes dominate BC- and SO 4-induced PET changes.« less

Simulated responses of terrestrial aridity to black carbon and sulfate aerosols: LIN: SIMULATED RESPONSES ARIDITY

DOE PAGES

Lin, L.; Gettelman, A.; Xu, Y.; ...

2016-01-27

Aridity index (AI), defined as the ratio of precipitation to potential evapotranspiration (PET), is a measure of the dryness of terrestrial climate. Global climate models generally project future decreases of AI (drying) associated with global warming scenarios driven by increasing greenhouse gas and declining aerosols. Given their different effects in the climate system, scattering and absorbing aerosols may affect AI differently. Here we explore the terrestrial aridity responses to anthropogenic black carbon (BC) and sulfate (SO4) aerosols with Community Earth System Model simulations. Positive BC radiative forcing decreases precipitation averaged over global land at a rate of 0.9%/°C of globalmore » mean surface temperature increase (moderate drying), while BC radiative forcing increases PET by 1.0%/°C (also drying). BC leads to a global decrease of 1.9%/°C in AI (drying). SO4 forcing is negative and causes precipitation a decrease at a rate of 6.7%/°C cooling (strong drying). PET also decreases in response to SO4 aerosol cooling by 6.3%/°C cooling (contributing to moistening). Thus, SO4 cooling leads to a small decrease in AI (drying) by 0.4%/°C cooling. Despite the opposite effects on global mean temperature, BC and SO4 both contribute to the twentieth century drying (AI decrease). Sensitivity test indicates that surface temperature and surface available energy changes dominate BC- and SO4-induced PET changes.« less

A Natural Alliance: The New Role for Black Women

ERIC Educational Resources Information Center

Rickman, Geraldine

1974-01-01

Black women represent the legitimate instruments by which the women's movement and the black movement can forge a power wedge for accomplishing significant change that will benefit both groups--namely, change relating to legal, economic, social, educational, and political issues. (Author)

Reflection from the strong gravity regime in a lensed quasar at redshift z = 0.658.

PubMed

Reis, R C; Reynolds, M T; Miller, J M; Walton, D J

2014-03-13

The co-evolution of a supermassive black hole with its host galaxy through cosmic time is encoded in its spin. At z > 2, supermassive black holes are thought to grow mostly by merger-driven accretion leading to high spin. It is not known, however, whether below z ≈ 1 these black holes continue to grow by coherent accretion or in a chaotic manner, though clear differences are predicted in their spin evolution. An established method of measuring the spin of black holes is through the study of relativistic reflection features from the inner accretion disk. Owing to their greater distances from Earth, there has hitherto been no significant detection of relativistic reflection features in a moderate-redshift quasar. Here we report an analysis of archival X-ray data together with a deep observation of a gravitationally lensed quasar at z = 0.658. The emission originates within three or fewer gravitational radii from the black hole, implying a spin parameter (a measure of how fast the black hole is rotating) of a = 0.87(+0.08)(-0.15) at the 3σ confidence level and a > 0.66 at the 5σ level. The high spin found here is indicative of growth by coherent accretion for this black hole, and suggests that black-hole growth at 0.5 ≤ z ≤ 1 occurs principally by coherent rather than chaotic accretion episodes.

Seeking Sanctuary: (Re)Claiming the Power of Historically Black Colleges and Universities as Places of Black Refuge

ERIC Educational Resources Information Center

Mobley, Steve D., Jr.

2017-01-01

Historically, Black colleges and universities (HBCUs) have consistently functioned as engines of social change and racial uplift and are among the few places where Black culture is placed at the forefront, appreciated, and sustained. Today and in the future, it will be paramount for HBCUs to not only embody their eminent legacies of social change,…

A case study of the impact of inaccurate cause-of-death reporting on health disparity tracking: New York City premature cardiovascular mortality.

PubMed

Johns, Lauren E; Madsen, Ann M; Maduro, Gil; Zimmerman, Regina; Konty, Kevin; Begier, Elizabeth

2013-04-01

Heart disease death overreporting is problematic in New York City (NYC) and other US jurisdictions. We examined whether overreporting affects the premature (< 65 years) heart disease death rate disparity between non-Hispanic Blacks and non-Hispanic Whites in NYC. We identified overreporting hospitals and used counts of premature heart disease deaths at reference hospitals to estimate corrected counts. We then corrected citywide, age-adjusted premature heart disease death rates among Blacks and Whites and a White-Black premature heart disease death disparity. At overreporting hospitals, 51% of the decedents were White compared with 25% at reference hospitals. Correcting the heart disease death counts at overreporting hospitals decreased the age-adjusted premature heart disease death rate 10.1% (from 41.5 to 37.3 per 100,000) among Whites compared with 4.2% (from 66.2 to 63.4 per 100,000) among Blacks. Correction increased the White-Black disparity 6.1% (from 24.6 to 26.1 per 100,000). In 2008, NYC's White-Black premature heart disease death disparity was underestimated because of overreporting by hospitals serving larger proportions of Whites. Efforts to reduce overreporting may increase the observed disparity, potentially obscuring any programmatic or policy-driven advances.

The mass function of black holes 1

NASA Astrophysics Data System (ADS)

Natarajan, Priyamvada; Volonteri, Marta

2012-05-01

In this paper, we compare the observationally derived black hole mass function (BHMF) of luminous (>1045-1046 erg s-1) broad-line quasars (BLQSOs) at 1 < z < 4.5 drawn from the Sloan Digital Sky Survey (SDSS) presented by Kelly et al., with models of merger-driven black hole (BH) growth in the context of standard hierarchical structure formation models. In these models, we explore two distinct black hole seeding prescriptions at the highest redshifts: 'light seeds'- remnants of Population III stars and 'massive seeds' that form from the direct collapse of pre-galactic discs. The subsequent merger triggered mass build-up of the black hole population is tracked over cosmic time under the assumption of a fixed accretion rate as well as rates drawn from the distribution derived by Merloni & Heinz. Four model snapshots at z= 1.25, 2, 3.25 and 4.25 are compared with the SDSS-derived BHMFs of BLQSOs. We find that the light seed models fall short of reproducing the observationally derived mass function of BLQSOs at MBH > 109 M⊙ throughout the redshift range; the massive seed models with a fixed accretion rate of 0.3 Edd, or with accretion rates drawn from the Merloni & Heinz distribution provide the best fit to the current observational data at z > 2, although they overestimate the high-mass end of the mass function at lower redshifts. At low redshifts, a drastic drop in the accretion rate is observed and this is explained as arising due to the diminished gas supply available due to consumption by star formation or changes in the geometry of the inner feeding regions. Therefore, the overestimate at the high-mass end of the black hole mass function for the massive seed models can be easily modified, as the accretion rate is likely significantly lower at these epochs than what we assume. For the Merloni & Heinz model, examining the Eddington ratio distributions fEdd, we find that they are almost uniformly sampled from fEdd= 10-2 to 1 at z≃ 1, while at high redshift, current observations suggest accretion rates close to Eddington, if not mildly super-Eddington, at least for these extremely luminous quasars. Our key findings are that the duty cycle of super-massive black holes powering BLQSOs increases with increasing redshift for all models and models with Population III remnants as black hole seeds are unable to fit the observationally derived BHMFs for BLQSOs, lending strong support for the massive seeding model.

Thermal Disk Winds in X-Ray Binaries: Realistic Heating and Cooling Rates Give Rise to Slow, but Massive, Outflows

NASA Astrophysics Data System (ADS)

Higginbottom, N.; Proga, D.; Knigge, C.; Long, K. S.

2017-02-01

A number of X-ray binaries exhibit clear evidence for the presence of disk winds in the high/soft state. A promising driving mechanism for these outflows is mass loss driven by the thermal expansion of X-ray heated material in the outer disk atmosphere. Higginbottom & Proga recently demonstrated that the properties of thermally driven winds depend critically on the shape of the thermal equilibrium curve, since this determines the thermal stability of the irradiated material. For a given spectral energy distribution, the thermal equilibrium curve depends on an exact balance between the various heating and cooling mechanisms at work. Most previous work on thermally driven disk winds relied on an analytical approximation to these rates. Here, we use the photoionization code cloudy to generate realistic heating and cooling rates which we then use in a 2.5D hydrodynamic model computed in ZEUS to simulate thermal winds in a typical black hole X-ray binary. We find that these heating and cooling rates produce a significantly more complex thermal equilibrium curve, with dramatically different stability properties. The resulting flow, calculated in the optically thin limit, is qualitatively different from flows calculated using approximate analytical rates. Specifically, our thermal disk wind is much denser and slower, with a mass-loss rate that is a factor of two higher and characteristic velocities that are a factor of three lower. The low velocity of the flow—{v}\\max ≃ 200 km s-1—may be difficult to reconcile with observations. However, the high mass-loss rate—15 × the accretion rate—is promising, since it has the potential to destabilize the disk. Thermally driven disk winds may therefore provide a mechanism for state changes.

Psychosocial stress and 13-year BMI change among blacks: the Pitt County Study.

PubMed

Fowler-Brown, Angela G; Bennett, Gary G; Goodman, Melody S; Wee, Christina C; Corbie-Smith, Giselle M; James, Sherman A

2009-11-01

Adverse psychosocial exposures may partially drive the high rates of obesity among blacks. The objective of this study was to prospectively examine the relationship between perceived psychosocial stress and percent change in BMI among adult black men and women. We used data from 756 women and 416 men who were participants in the Pitt County Study, a community-based, prospective cohort study of blacks in eastern North Carolina. Participants were aged 25-50 years of age on entry into the study in 1988 and follow-up was obtained in 2001. Using multivariable linear regression, we calculated the adjusted mean percentage change in BMI over the follow-up period for each tertile of baseline measures of the Perceived Stress Scale (low, medium, and high), adjusted for potential confounders. For black women, higher levels of psychosocial stress at baseline predicted higher adjusted percentage increase in BMI over the 13-year follow-up: low stress 12.0% (95% CI 9.6-14.4), medium stress 16.3% (95% CI 13.7-18.9), and high stress 15.5% (95% CI 13.1-17.8). For black men, perceived stress was not associated with percent BMI change. These data suggest that interventions targeting obesity in black women should consider the potential impact of emotional stress on weight change.

Input-driven versus turnover-driven controls of simulated changes in soil carbon due to land-use change

NASA Astrophysics Data System (ADS)

Nyawira, Sylvia; Nabel, Julia; Brovkin, Victor; Pongratz, Julia

2017-04-01

Modelling studies estimate a global loss in soil carbon caused by land-use changes (LUCs) over the last century. Although it is known that this loss stems from the changes in quantity of litter inputs from the vegetation to the soil (input-driven) and the changes in turnover of carbon in the soil (turnover-driven) associated with LUC, the individual contribution of these two controls to the total changes have not been assessed. Using the dynamic global vegetation model JSBACH, we apply a factor separation approach to isolate the contribution of the input-driven and turnover-driven changes, as well as their synergies, to the total changes in soil carbon from LUC. To assess how land management through crop and wood harvest influences the controls, we compare our results for simulations with and without land management. Our results reveal that for the afforested regions both the input-driven and turnover-driven changes generally result in soil carbon gain, whereas deforested regions exhibit a loss. However, for regions where croplands have increased at the expense of grasslands and pastures, the input-driven changes result in a loss that is partly offset by a gain via the turnover-driven changes. This gain stems from a decrease in the fire-related carbon losses when grasslands or pastures are replaced with croplands. Omitting land management reduces the carbon losses in regions where natural vegetation has been converted to croplands and enhances the gain in afforested regions. The global simulated losses are substantially reduced from 54.0 Pg C to 22.0 Pg C, with the input-driven losses reducing from 54.7 Pg C to 24.9 Pg C. Our study shows that the dominating control of soil carbon losses is through the input-driven changes, which are more directly influenced by human management than the turnover-driven ones.

Laboratory plate tectonics: a new experiment.

PubMed

Gans, R F

1976-03-26

A "continent" made of a layer of hexagonally packed black polyethylene spheres floating in clear silicon oil breaks into subcontinents when illuminated by an ordinary incandescent light bulb. This experiment may be a useful model of plate tectonics driven by horizontal temperature gradients. Measurements of the spreading rate are made to establish the feasibility of this model.

A Novel Approach for Determining Source–Receptor Relationships in Model Simulations: A Case Study of Black Carbon Transport in Northern Hemisphere Winter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Po-Lun; Gattiker, J. R.; Liu, Xiaohong

2013-06-27

A Gaussian process (GP) emulator is applied to quantify the contribution of local and remote emissions of black carbon (BC) on the BC concentrations in different regions using a Latin Hypercube sampling strategy for emission perturbations in the offline version of the Community Atmosphere Model Version 5.1 (CAM5) simulations. The source-receptor relationships are computed based on simulations constrained by a standard free-running CAM5 simulation and the ERA-Interim reanalysis product. The analysis demonstrates that the emulator is capable of retrieving the source-receptor relationships based on a small number of CAM5 simulations. Most regions are found susceptible to their local emissions. Themore » emulator also finds that the source-receptor relationships retrieved from the model-driven and the reanalysis-driven simulations are very similar, suggesting that the simulated circulation in CAM5 resembles the assimilated meteorology in ERA-Interim. The robustness of the results provides confidence for applying the emulator to detect dose-response signals in the climate system.« less

Dynamically important magnetic fields near supermassive black holes in radio-loud AGN

NASA Astrophysics Data System (ADS)

Savolainen, Tuomas; Zamaninasab, Mohammad; Clausen-Brown, Eric; Tchekhovskoy, Alexander

The powerful radio jets ejected from the vicinity of accreting supermassive black holes in active galactic nuclei are thought to be formed by magnetic forces. However, there is little observational evidence of the actual strength of the magnetic fields in the jet-launching region, and in the accretion disks, of AGN. We have collected from the literature jet magnetic field estimates determined by very long baseline interferometry observations of the opacity-driven core-shift effect for 76 blazars and radio galaxies. We show that the jet magnetic flux of these radio-loud AGN tightly correlates with their accretion disk luminosity -- over seven orders of magnitude in accretion power. Moreover, the estimated magnetic flux threading the black hole quantitatively agrees with the saturation value expected in the magnetically arrested disk scenario. This implies that black holes in many, if not most, of the radio-loud AGN are surrounded by accretion disks that have dynamically important magnetic fields. Such disks behave very differently from the standard model disks with sub-equipartition magnetic fields, which may have important consequences for attempts to interpret disk spectral energy distributions or signatures of the possible black hole shadow in mm-VLBI images.

On the origin of the HLX-1 outbursts

NASA Astrophysics Data System (ADS)

Sun, Mouyuan; Gu, Wei-Min; Yan, Zhen; Wu, Qingwen; Liu, Tong

2016-11-01

HLX-1, currently the best intermediate-mass black hole candidate, has undergone seven violent outbursts, each with a peak X-ray luminosity of Lpeak,X ˜ 1042 erg s-1. Interestingly, the properties of the HLX-1 outbursts evolve with time. In this work, we aim to constrain the physical parameters of the central engine of the HLX-1 outbursts in the framework of the black hole accretion. We find that the physical properties of the HLX-1 outbursts are consistent with being driven by the radiation pressure instability. This scenario can explain the evolution of the recurrent time-scales of the HLX-1 outbursts as a function of the durations.

Trends in group inequalities and interindividual inequalities in BMI in the United States, 1993-2012.

PubMed

Krishna, Aditi; Razak, Fahad; Lebel, Alexandre; Smith, George Davey; Subramanian, S V

2015-03-01

Marked increases in mean body mass index (BMI) and prevalence of obesity and overweight in the United States are well known. However, whether these average increases were accompanied by changing dispersion (or SD) remains understudied. We investigated population-level changes in the BMI distribution over time to understand how changes in dispersion reflect between-group compared with within-group inequalities in weight gain in the United States. Using data from the Behavioral Risk Factor Surveillance System survey (1993-2012), we analyzed associations between mean, SD, and median BMI and BMI at the 5th and 95th percentiles for 3,050,992 non-Hispanic white, non-Hispanic black, and Hispanic men and women aged 25-64 y. Overall, an increase of 1.0 in mean BMI (in kg/m²) was associated with an increase of 0.70 (95% CI: 0.67, 0.73) in the SD of BMI. A change of 1.0 in median BMI was associated with a change of 0.18 (95% CI: 0.14, 0.21) in the BMI value at the 5th percentile compared with a change of 2.94 (95% CI: 2.81, 3.07) at the 95th percentile. Quantile-quantile plots showed unequal changes in the BMI distribution, with pronounced changes at higher percentiles. Similar patterns were observed in subgroups stratified by sex, race-ethnicity, and education with non-Hispanic black women and women with less than a high school education having highest mean BMI, SD of BMI, and BMI values at the 5th and 95th percentiles. Mean BMI and the percentage of overweight and obese individuals do not fully describe population changes in BMI. Increases in within-group inequality in BMI represent an underrecognized characteristic of population-level weight gain. Crucially, similar increases in dispersion within groups suggest that growing inequalities in BMI at the population level are not driven by these socioeconomic and demographic factors. Future research should focus on understanding factors driving inequalities in weight gain between individuals. © 2015 American Society for Nutrition.

Erratic Black Hole Regulates Itself

NASA Astrophysics Data System (ADS)

2009-03-01

New results from NASA's Chandra X-ray Observatory have made a major advance in explaining how a special class of black holes may shut off the high-speed jets they produce. These results suggest that these black holes have a mechanism for regulating the rate at which they grow. Black holes come in many sizes: the supermassive ones, including those in quasars, which weigh in at millions to billions of times the mass of the Sun, and the much smaller stellar-mass black holes which have measured masses in the range of about 7 to 25 times the Sun's mass. Some stellar-mass black holes launch powerful jets of particles and radiation, like seen in quasars, and are called "micro-quasars". The new study looks at a famous micro-quasar in our own Galaxy, and regions close to its event horizon, or point of no return. This system, GRS 1915+105 (GRS 1915 for short), contains a black hole about 14 times the mass of the Sun that is feeding off material from a nearby companion star. As the material swirls toward the black hole, an accretion disk forms. This system shows remarkably unpredictable and complicated variability ranging from timescales of seconds to months, including 14 different patterns of variation. These variations are caused by a poorly understood connection between the disk and the radio jet seen in GRS 1915. Chandra, with its spectrograph, has observed GRS 1915 eleven times since its launch in 1999. These studies reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole. The wind is believed to shut down the jet by depriving it of matter that would have otherwise fueled it. Conversely, once the wind dies down, the jet can re-emerge. "We think the jet and wind around this black hole are in a sort of tug of war," said Joseph Neilsen, Harvard graduate student and lead author of the paper appearing in the journal Nature. "Sometimes one is winning and then, for reasons we don'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 system," said Lee. "So, we can learn a tremendous amount about black holes by just studying stellar-mass black holes like this one." It is not known what causes the jet to turn on again once the wind dies down, and this remains one of the major unsolved mysteries in astronomy. "Every major observatory, ground and space, has been used to study this black hole for the past two decades," said Neilsen. "Although we still don't have all the answers, we think our work is a step in the right direction." This was work made using Chandra's High Energy Transmission Gratings Spectrometer. These results appear in the March 26th issue of Nature. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

The Impatient Press: Placing Black Newspapers in the Ideologies of Black Progress.

ERIC Educational Resources Information Center

Caspari, Genevieve G.

Unlike its white counterpart, the black press has historically exceeded its role of information source. Specialized black media were founded to decry racial conflict and gain civil rights. Only rarely, and secondarily, have black papers achieved commercial success. The purposes of black papers have changed with the society they serve. Ideologies…

The Black Lives Matter Movement and Historically Black Colleges and Universities

ERIC Educational Resources Information Center

Gasman, Marybeth

2017-01-01

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

Can singular examples change implicit attitudes in the real-world?

PubMed Central

Roos, Leslie E.; Lebrecht, Sophie; Tanaka, James W.; Tarr, Michael J.

2013-01-01

Implicit attitudes about social groups persist independently of explicit beliefs and can influence not only social behavior, but also medical and legal practices. Although examples presented in the laboratory can alter such implicit attitudes, it is unclear whether the same influence is exerted by real-world exemplars. Following the 2008 US election, Plant et al. reported that the Implicit Association Test or “IAT” revealed a decrease in negative implicit attitudes toward African-Americans. However, a large-scale study also employing the IAT found little evidence for a change in implicit attitudes pre- and post-election. Here we present evidence that the 2008 US election may have facilitated at least a temporary change in implicit racial attitudes in the US. Our results rely on the Affective Lexical Priming Score or “ALPS” and pre- and post-election measurements for both US and non-US participants. US students who, pre-election, exhibited negative associations with black faces, post-election showed positive associations with black faces. Canadian students pre- and post-election did not show a similar shift. To account for these findings, we posit that the socio-cognitive processes underlying ALPS are different from those underlying the IAT. Acknowledging that we cannot form a causal link between an intervening real-world event and laboratory-measured implicit attitudes, we speculate that our findings may be driven by the fact that the 2008 election campaign included extremely positive media coverage of President Obama and prominently featured his face in association with positive words—similar to the structure of ALPS. Even so, our real-world finding adds to the literature demonstrating the malleability of implicit attitudes and has implications for how we understand the socio-cognitive mechanisms underlying stereotypes. PMID:24046756

Resource-driven encounters among consumers and implications for the spread of infectious disease

PubMed Central

Flynn, Jason M.

2017-01-01

Animals share a variety of common resources, which can be a major driver of conspecific encounter rates. In this work, we implement a spatially explicit mathematical model for resource visitation behaviour in order to examine how changes in resource availability can influence the rate of encounters among consumers. Using simulations and asymptotic analysis, we demonstrate that, under a reasonable set of assumptions, the relationship between resource availability and consumer conspecific encounters is not monotonic. We characterize how the maximum encounter rate and associated critical resource density depend on system parameters like consumer density and the maximum distance from which consumers can detect and respond to resources. The assumptions underlying our theoretical model and analysis are motivated by observations of large aggregations of black-backed jackals at carcasses generated by seasonal outbreaks of anthrax among herbivores in Etosha National Park, Namibia. As non-obligate scavengers, black-backed jackals use carcasses as a supplemental food resource when they are available. While jackals do not appear to acquire disease from ingesting anthrax carcasses, changes in their movement patterns in response to changes in carcass abundance do alter jackals' conspecific encounter rate in ways that may affect the transmission dynamics of other diseases, such as rabies. Our theoretical results provide a method to quantify and analyse the hypothesis that the outbreak of a fatal disease among herbivores can potentially facilitate outbreaks of an entirely different disease among jackals. By analysing carcass visitation data, we find support for our model's prediction that the number of conspecific encounters at resource sites decreases with additional increases in resource availability. Whether or not this site-dependent effect translates to an overall decrease in encounters depends, unexpectedly, on the relationship between the maximum distance of detection and the resource density. PMID:29021163

Evaporation-driven instability of the precorneal tear film.

PubMed

Peng, Cheng-Chun; Cerretani, Colin; Braun, Richard J; Radke, C J

2014-04-01

Tear-film instability is widely believed to be a signature of eye health. When an interblink is prolonged, randomly distributed ruptures occur in the tear film. "Black spots" and/or "black streaks" appear in 15 to 40 s for normal individuals. For people who suffer from dry eye, tear-film breakup time (BUT) is typically less than a few seconds. To date, however, there is no satisfactory quantitative explanation for the origin of tear rupture. Recently, it was proposed that tear-film breakup is related to locally high evaporative thinning. A spatial variation in the thickness of the tear-film lipid layer (TFLL) may lead to locally elevated evaporation and subsequent tear-film breakup. We examine the local-evaporation-driven tear-film-rupture hypothesis in a one-dimensional (1-D) model for the evolution of a thin aqueous tear film overriding the cornea subject to locally elevated evaporation at its anterior surface and osmotic water influx at its posterior surface. Evaporation rate depends on mass transfer both through the coating lipid layer and through ambient air. We establish that evaporation-driven tear-film breakup can occur under normal conditions but only for higher aqueous evaporation rates. Predicted roles of environmental conditions, such as wind speed and relative humidity, on tear-film stability agree with clinical observations. More importantly, locally elevated evaporation leads to hyperosmolar spots in the tear film and, hence, vulnerability to epithelial irritation. In addition to evaporation rate, tear-film instability depends on the strength of healing flow from the neighboring region outside the breakup region, which is determined by the surface tension at the tear-film surface and by the repulsive thin-film disjoining pressure. This study provides a physically consistent and quantitative explanation for the formation of black streaks and spots in the human tear film during an interblink. Copyright © 2013 Elsevier B.V. All rights reserved.

Quenching star formation with quasar outflows launched by trapped IR radiation

NASA Astrophysics Data System (ADS)

Costa, Tiago; Rosdahl, Joakim; Sijacki, Debora; Haehnelt, Martin G.

2018-06-01

We present cosmological radiation-hydrodynamic simulations, performed with the code RAMSES-RT, of radiatively-driven outflows in a massive quasar host halo at z = 6. Our simulations include both single- and multi-scattered radiation pressure on dust from a quasar and are compared against simulations performed with thermal feedback. For radiation pressure-driving, we show that there is a critical quasar luminosity above which a galactic outflow is launched, set by the equilibrium of gravitational and radiation forces. While this critical luminosity is unrealistically high in the single-scattering limit for plausible black hole masses, it is in line with a ≈ 3 × 10^9 M_⊙ black hole accreting at its Eddington limit, if infrared (IR) multi-scattering radiation pressure is included. The outflows are fast (v ≳ 1000 km s^{-1}) and strongly mass-loaded with peak mass outflow rates ≈ 10^3 - 10^4 M_⊙ yr^{-1}, but short-lived (< 10 Myr). Outflowing material is multi-phase, though predominantly composed of cool gas, forming via a thermal instability in the shocked swept-up component. Radiation pressure- and thermally-driven outflows both affect their host galaxies significantly, but in different, complementary ways. Thermally-driven outflows couple more efficiently to diffuse halo gas, generating more powerful, hotter and more volume-filling outflows. IR radiation, through its ability to penetrate dense gas via diffusion, is more efficient at ejecting gas from the bulge. The combination of gas ejection through outflows with internal pressurisation by trapped IR radiation leads to a complete shut down of star formation in the bulge. We hence argue that radiation pressure-driven feedback may be an important ingredient in regulating star formation in compact starbursts, especially during the quasar's `obscured' phase.

Plague dynamics are driven by climate variation.

PubMed

Stenseth, Nils Chr; Samia, Noelle I; Viljugrein, Hildegunn; Kausrud, Kyrre Linné; Begon, Mike; Davis, Stephen; Leirs, Herwig; Dubyanskiy, V M; Esper, Jan; Ageyev, Vladimir S; Klassovskiy, Nikolay L; Pole, Sergey B; Chan, Kung-Sik

2006-08-29

The bacterium Yersinia pestis causes bubonic plague. In Central Asia, where human plague is still reported regularly, the bacterium is common in natural populations of great gerbils. By using field data from 1949-1995 and previously undescribed statistical techniques, we show that Y. pestis prevalence in gerbils increases with warmer springs and wetter summers: A 1 degrees C increase in spring is predicted to lead to a >50% increase in prevalence. Climatic conditions favoring plague apparently existed in this region at the onset of the Black Death as well as when the most recent plague pandemic arose in the same region, and they are expected to continue or become more favorable as a result of climate change. Threats of outbreaks may thus be increasing where humans live in close contact with rodents and fleas (or other wildlife) harboring endemic plague.

Gravitational signature of Schwarzschild black holes in dynamical Chern-Simons gravity

NASA Astrophysics Data System (ADS)

Molina, C.; Pani, Paolo; Cardoso, Vitor; Gualtieri, Leonardo

2010-06-01

Dynamical Chern-Simons gravity is an extension of general relativity in which the gravitational field is coupled to a scalar field through a parity-violating Chern-Simons term. In this framework, we study perturbations of spherically symmetric black hole spacetimes, assuming that the background scalar field vanishes. Our results suggest that these spacetimes are stable, and small perturbations die away as a ringdown. However, in contrast to standard general relativity, the gravitational waveforms are also driven by the scalar field. Thus, the gravitational oscillation modes of black holes carry imprints of the coupling to the scalar field. This is a smoking gun for Chern-Simons theory and could be tested with gravitational-wave detectors, such as LIGO or LISA. For negative values of the coupling constant, ghosts are known to arise, and we explicitly verify their appearance numerically. Our results are validated using both time evolution and frequency domain methods.

Jet Power vs. Black Hole Mass in Blazars: Exploring the Relationship in the Context of the B-Z Mechanism

NASA Astrophysics Data System (ADS)

Fernandes, Sunil; Schlegel, E.

2012-01-01

Recently, a tentative negative correlation between jet power and BH mass in a sample of GeV-TeV BL Lac objects(Zhang et al 2011). It was suggested that spin energy extraction could play a significant role in producing the jets and the jets are not purely accretion driven. Broderick et al (2011) recently explored the relationship between jet power and radio core luminosity building on Blanford et al (1979) theoretical work. Using this work we have studied the relationship between radio core luminosity (as a stand in for jet power) and black hole mass and have found a possible positive correlation in a sample of nearby BL Lac objects. The present poster attempts to explore this relationship in the context of the Blanford-Znajek mechanism which predicts jet power increases with black hole mass, spin rate, and accretion rate.

Wind and solar powered turbine

NASA Technical Reports Server (NTRS)

Wells, I. D.; Koh, J. L.; Holmes, M. (Inventor)

1984-01-01

A power generating station having a generator driven by solar heat assisted ambient wind is described. A first plurality of radially extendng air passages direct ambient wind to a radial flow wind turbine disposed in a centrally located opening in a substantially disc-shaped structure. A solar radiation collecting surface having black bodies is disposed above the fist plurality of air passages and in communication with a second plurality of radial air passages. A cover plate enclosing the second plurality of radial air passages is transparent so as to permit solar radiation to effectively reach the black bodies. The second plurality of air passages direct ambient wind and thermal updrafts generated by the black bodies to an axial flow turbine. The rotating shaft of the turbines drive the generator. The solar and wind drien power generating system operates in electrical cogeneration mode with a fuel powered prime mover.

Gravitational signature of Schwarzschild black holes in dynamical Chern-Simons gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molina, C.; Pani, Paolo; Cardoso, Vitor

2010-06-15

Dynamical Chern-Simons gravity is an extension of general relativity in which the gravitational field is coupled to a scalar field through a parity-violating Chern-Simons term. In this framework, we study perturbations of spherically symmetric black hole spacetimes, assuming that the background scalar field vanishes. Our results suggest that these spacetimes are stable, and small perturbations die away as a ringdown. However, in contrast to standard general relativity, the gravitational waveforms are also driven by the scalar field. Thus, the gravitational oscillation modes of black holes carry imprints of the coupling to the scalar field. This is a smoking gun formore » Chern-Simons theory and could be tested with gravitational-wave detectors, such as LIGO or LISA. For negative values of the coupling constant, ghosts are known to arise, and we explicitly verify their appearance numerically. Our results are validated using both time evolution and frequency domain methods.« less

General Relativistic Simulations of Magnetized Plasmas Around Merging Supermassive Black Holes

NASA Technical Reports Server (NTRS)

Giacomazzo, Bruno; Baker, John G.; Miller, M. Coleman; Reynolds, Christopher S.; van Meter, James R.

2012-01-01

Coalescing supermassive black hole binaries are produced by the mergers of galaxies and are the most powerful sources of gravitational waves accessible to space-based gravitational observatories. Some such mergers may occur in the presence of matter and magnetic fields and hence generate an electromagnetic counterpart. In this paper we present the first general relativistic simulations of magnetized plasma around merging supermassive black holes using the general relativistic magnetohydrodynamic code Whisky. By considering different magnetic field strengths, going from non-magnetically dominated to magnetically dominated regimes, we explore how magnetic fields affect the dynamics of the plasma and the possible emission of electromagnetic signals. In particular we observe, total amplification of the magnetic field of approx 2 orders of magnitude which is driven by the accretion onto the binary and that leads to stronger electromagnetic signals than in the force-free regime where such amplifications are not possible.

Black Political Socialization and Political Change: The Black Panther Party Platform as a "Model" of Radical Political Socialization

ERIC Educational Resources Information Center

McLemore, Leslie Burl

1975-01-01

Considers the potential impact of black revolutionary nationalism--cultural and military--upon the social patterns of black people, arguing that a racial, cultural, and military approach through black organizations with a highly developed system of communications holds the key to black salvation in America. (Author/JM)

Costs and global impacts of black carbon abatement strategies

NASA Astrophysics Data System (ADS)

Rypdal, Kristin; Rive, Nathan; Berntsen, Terje K.; Klimont, Zbigniew; Mideksa, Torben K.; Myhre, Gunnar; Skeie, Ragnhild B.

2009-09-01

Abatement of particulate matter has traditionally been driven by health concerns rather than its role in global warming. Here we assess future abatement strategies in terms of how much they reduce the climate impact of black carbon (BC) and organic carbon (OC) from contained combustion. We develop global scenarios which take into account regional differences in climate impact, costs of abatement and ability to pay, as well as both the direct and indirect (snow-albedo) climate impact of BC and OC. To represent the climate impact, we estimate consistent region-specific values of direct and indirect global warming potential (GWP) and global temperature potential (GTP). The indirect GWP has been estimated using a physical approach and includes the effect of change in albedo from BC deposited on snow. The indirect GWP is highest in the Middle East followed by Russia, Europe and North America, while the total GWP is highest in the Middle East, Africa and South Asia. We conclude that prioritizing emission reductions in Asia represents the most cost-efficient global abatement strategy for BC because Asia is (1) responsible for a large share of total emissions, (2) has lower abatement costs compared to Europe and North America and (3) has large health cobenefits from reduced PM10 emissions.

Ecology-driven stereotypes override race stereotypes.

PubMed

Williams, Keelah E G; Sng, Oliver; Neuberg, Steven L

2016-01-12

Why do race stereotypes take the forms they do? Life history theory posits that features of the ecology shape individuals' behavior. Harsh and unpredictable ("desperate") ecologies induce fast strategy behaviors such as impulsivity, whereas resource-sufficient and predictable ("hopeful") ecologies induce slow strategy behaviors such as future focus. We suggest that individuals possess a lay understanding of ecology's influence on behavior, resulting in ecology-driven stereotypes. Importantly, because race is confounded with ecology in the United States, we propose that Americans' stereotypes about racial groups actually reflect stereotypes about these groups' presumed home ecologies. Study 1 demonstrates that individuals hold ecology stereotypes, stereotyping people from desperate ecologies as possessing faster life history strategies than people from hopeful ecologies. Studies 2-4 rule out alternative explanations for those findings. Study 5, which independently manipulates race and ecology information, demonstrates that when provided with information about a person's race (but not ecology), individuals' inferences about blacks track stereotypes of people from desperate ecologies, and individuals' inferences about whites track stereotypes of people from hopeful ecologies. However, when provided with information about both the race and ecology of others, individuals' inferences reflect the targets' ecology rather than their race: black and white targets from desperate ecologies are stereotyped as equally fast life history strategists, whereas black and white targets from hopeful ecologies are stereotyped as equally slow life history strategists. These findings suggest that the content of several predominant race stereotypes may not reflect race, per se, but rather inferences about how one's ecology influences behavior.

Stellar dynamics around a massive black hole - II. Resonant relaxation

NASA Astrophysics Data System (ADS)

Sridhar, S.; Touma, Jihad R.

2016-06-01

We present a first-principles theory of resonant relaxation (RR) of a low-mass stellar system orbiting a more massive black hole (MBH). We first extend the kinetic theory of Gilbert to include the Keplerian field of a black hole of mass M•. Specializing to a Keplerian stellar system of mass M ≪ M•, we use the orbit-averaging method of Sridhar & Touma to derive a kinetic equation for RR. This describes the collisional evolution of a system of N ≫ 1 Gaussian rings in a reduced 5-dim space, under the combined actions of self-gravity, 1 post-Newtonian (PN) and 1.5 PN relativistic effects of the MBH and an arbitrary external potential. In general geometries, RR is driven by both apsidal and nodal resonances, so the distinction between scalar RR and vector RR disappears. The system passes through a sequence of quasi-steady secular collisionless equilibria, driven by irreversible two-ring correlations that accrue through gravitational interactions, both direct and collective. This correlation function is related to a `wake function', which is the linear response of the system to the perturbation of a chosen ring. The wake function is easier to appreciate, and satisfies a simpler equation, than the correlation function. We discuss general implications for the interplay of secular dynamics and non-equilibrium statistical mechanics in the evolution of Keplerian stellar systems towards secular thermodynamic equilibria, and set the stage for applications to the RR of axisymmetric discs in Paper III.

Cardiorespiratory Fitness Change and Mortality Risk Among Black and White Patients: Henry Ford Exercise Testing (FIT) Project.

PubMed

Ehrman, Jonathan K; Brawner, Clinton A; Al-Mallah, Mouaz H; Qureshi, Waqas T; Blaha, Michael J; Keteyian, Steven J

2017-10-01

Little is known about the relationship of change in cardiorespiratory fitness and mortality risk in Black patients. This study assessed change in cardiorespiratory fitness and its association with all-cause mortality risk in Black and White patients. This is a retrospective, longitudinal, observational cohort study of 13,345 patients (age = 55 ± 11 years; 39% women; 26% black) who completed 2 exercise tests, at least 12 months apart at Henry Ford Hospital, Detroit, Mich. All-cause mortality was identified through April 2013. Data were analyzed in 2015-2016 using Cox regression to calculate hazard ratios (HR) for risk of mortality associated with change in sex-specific cardiorespiratory fitness. Mean time between the tests was 3.4 years (interquartile range 1.9-5.6 years). During 9.1 years (interquartile range 6.3-11.6 years) of follow-up, there were 1931 (14%) deaths (16.5% black, 13.7% white). For both races, change in fitness from Low to the Intermediate/High category resulted in a significant reduction of death risk (HR 0.65 [95% confidence interval (CI), 0.49-0.87] for Black; HR 0.41 [95% CI, 0.34-0.51] for White). Each 1-metabolic-equivalent-of-task increase was associated with a reduced mortality risk in black (HR 0.84 [95% CI, 0.81-0.89]) and white (HR 0.87 [95% CI, 0.82-0.86]) patients. There was no interaction by race. Among black and white patients, change in cardiorespiratory fitness from Low to Intermediate/High fitness was associated with a 35% and 59% lower risk of all-cause mortality, respectively. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk management policy and black-box warnings: a qualitative analysis of US FDA proceedings.

PubMed

Cook, Daniel M; Gurugubelli, Rama K; Bero, Lisa A

2009-01-01

The US FDA increasingly applies risk management to drug safety policy. Little is known about the process by which the FDA approves labelling changes. Although advisory committees can recommend any of the risk management tools, including the use of 'black-box warnings', it is unknown whether they deliberate on these questions or how they apply the principles of risk minimization or management during their considerations of drug licensing. To examine the process by which risk management is considered by the FDA, including the role of FDA advisory committees. We also aimed to identify and describe drug labelling changes and additions, including the prevalence of black-box warnings. We electronically obtained publicly available information regarding drug approvals, drug revisions and advisory committee meetings over 3 years (2004-6) from the FDA. Data in the form of meeting transcripts and full histories of labelling changes were collected on drugs discussed by advisory committees. We then searched and qualitatively analysed the meeting transcripts to identify themes in the discussion. We also created a database of all prescription drug labelling changes for 3 years and examined which drugs have had the most changes. We describe the risk management consideration process and report the frequency and characteristics of labelling changes. Excerpts from the transcripts are selected to illustrate both typical and atypical features of the discussion. A total of 174 black-box changes were made in the 3-year period of our study, of which 77 were new black-box warnings and 97 were revisions in black-box warnings. Of 77 new black-box warning additions, only 11 drugs were discussed by the advisory committees. Of the 17 most frequently revised drug labels in these 3 years, two were discussed in the advisory committee meetings. Advisory meeting discussions revealed confusion about black-box warnings and emphasized potential consequences of the warnings rather than their content. The safety labelling of drugs on the market is changed often. Panels of advisors consider only a few drugs, rarely discuss the labelling requirements, and display confusion about applying black-box warnings. The creation and application of black-box warnings on prescription medications should receive closer attention from the FDA and its advisors.

The close environments of accreting massive black holes are shaped by radiative feedback.

PubMed

Ricci, Claudio; Trakhtenbrot, Benny; Koss, Michael J; Ueda, Yoshihiro; Schawinski, Kevin; Oh, Kyuseok; Lamperti, Isabella; Mushotzky, Richard; Treister, Ezequiel; Ho, Luis C; Weigel, Anna; Bauer, Franz E; Paltani, Stephane; Fabian, Andrew C; Xie, Yanxia; Gehrels, Neil

2017-09-27

The majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies across the electromagnetic spectrum. The origin of this trend may be driven by the increase in the inner radius of the obscuring material with incident luminosity, which arises from the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism that regulates obscuration unclear. Here we report a systematic multi-wavelength survey of hard-X-ray-selected black holes that reveals that radiative feedback on dusty gas is the main physical mechanism that regulates the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas is located within a few to tens of parsecs of the accreting supermassive black hole (within the sphere of influence of the black hole), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate.

Trade and the Future of China's Black Carbon Emissions

NASA Astrophysics Data System (ADS)

Persad, G.; Oppenheimer, M.; Naik, V.

2016-12-01

Emissions of black carbon aerosols in China have increased by over 200% during the last 50 years, with negative implications both for human health and for regional and global climate. The Representative Concentration Pathway (RCP) emissions scenarios all assume that China's future black carbon emissions will decrease. However, this decline partially depends on the assumption that the evolution of future pollutant emissions in developing nations will match the observed historical relationship between air quality and income in developed nations. Recent research has demonstrated that a substantial portion of China's current black carbon emissions are driven by the production of goods exported for consumption elsewhere. This constitutes an external demand for black carbon-emitting activity in China that is much smaller in the developed nations on which the historical air quality/income relationship is based. We here show using integrated assessment model output, general circulation modeling, and emissions and economic data that (1) China must achieve a faster technological and regulatory evolution than did developed countries in order achieve the same air quality/income trajectory; (2) China's uniquely large share of export-related black carbon-emitting activities and their potential growth are a plausible explanation for this disparity; and (3) the climate and health implications of these export-related black carbon emissions, if unmitigated, are of interest from a policy perspective. Together these results indicate that the production of goods for export will steepen the mitigation curve for China relative to developed nations, if China is to achieve the future black carbon emissions reductions assumed in the RCPs.

The close environments of accreting massive black holes are shaped by radiative feedback

NASA Astrophysics Data System (ADS)

Ricci, Claudio; Trakhtenbrot, Benny; Koss, Michael J.; Ueda, Yoshihiro; Schawinski, Kevin; Oh, Kyuseok; Lamperti, Isabella; Mushotzky, Richard; Treister, Ezequiel; Ho, Luis C.; Weigel, Anna; Bauer, Franz E.; Paltani, Stephane; Fabian, Andrew C.; Xie, Yanxia; Gehrels, Neil

2017-09-01

The majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies across the electromagnetic spectrum. The origin of this trend may be driven by the increase in the inner radius of the obscuring material with incident luminosity, which arises from the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism that regulates obscuration unclear. Here we report a systematic multi-wavelength survey of hard-X-ray-selected black holes that reveals that radiative feedback on dusty gas is the main physical mechanism that regulates the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas is located within a few to tens of parsecs of the accreting supermassive black hole (within the sphere of influence of the black hole), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate.

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2013 CFR

2013-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2012 CFR

2012-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2011 CFR

2011-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2014 CFR

2014-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

14 CFR 36.9 - Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category...

Code of Federal Regulations, 2010 CFR

2010-01-01

... airplanes and propeller-driven commuter category airplanes. 36.9 Section 36.9 Aeronautics and Space FEDERAL... AIRWORTHINESS CERTIFICATION General § 36.9 Acoustical change: Propeller-driven small airplanes and propeller-driven commuter category airplanes. For propeller-driven small airplanes in the primary, normal, utility...

Beyond Einstein: From the Big Bang to Black Holes

NASA Astrophysics Data System (ADS)

White, N.

Beyond Einstein is a science-driven program of missions, education and outreach, and technology, to address three questions: What powered the Big Bang? What happens to space, time, and matter at the edge of a Black Hole? What is the mysterious Dark Energy pulling the universe apart? To address the science objectives, Beyond Einstein contains several interlinked elements. The strategic missions Constellation-X and LISA primarily investigate the nature of black holes. Constellation-X is a spectroscopic observatory that uses X-ray emitting atoms as clocks to follow the fate of matter falling into black holes. LISA will be the first space-based gravitational wave observatory uses gravitational waves to measure the dynamic structure of space and time around black holes. Moderate sized probes that are fully competed, peer-reviewed missions (300M-450M) launched every 3-5 years to address the focussed science goals: 1) Determine the nature of the Dark Energy that dominates the universe, 2) Search for the signature of the beginning of the Big Bang in the microwave background and 3) Take a census of Black Holes of all sizes and ages in the universe. The final element is a Technology Program to enable ultimate Vision Missions (after 2015) to directly detect gravitational waves echoing from the beginning of the Big Bang, and to directly image matter near the event horizon of a Black Hole. An associated Education and Public Outreach Program will inspire the next generation of scientists, and support national science standards and benchmarks.

Bright vigorous winds as signposts of supermassive black hole birth

NASA Astrophysics Data System (ADS)

Fiacconi, Davide; Rossi, Elena M.

2016-01-01

The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a 104-105 M⊙ black hole at the centre of a protogalaxy at z ˜ 20-10. Super-Eddington accretion, however, may be accompanied by vigorous mass-loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and 104 M⊙ yr-1, mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan et al. that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass >104 M⊙ can only form within mass reservoirs ≳107 M⊙, unless they are refilled at huge rates (≳100 M⊙ yr-1). This may imply that only very massive haloes (>109 M⊙) at those redshifts can harbour massive seeds. Contrary to previous claims, these winds are expected to be relatively bright (1044-1047 erg s-1), blue (Teff ˜ 8000 K) objects, that while eluding the Hubble Space Telescope, could be observed by the James Webb Space Telescope.

Quantifying the variability of potential black carbon transport from cropland burning in Russia driven by atmospheric blocking events

NASA Astrophysics Data System (ADS)

Hall, Joanne; Loboda, Tatiana

2018-05-01

The deposition of short-lived aerosols and pollutants on snow above the Arctic Circle transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Specifically, black carbon has received a great deal of attention due to its absorptive efficiency and its fairly complex influence on the climate. Cropland burning in Russia is a large contributor to the black carbon emissions deposited directly onto the snow in the Arctic region during the spring when the impact on the snow/ice albedo is at its highest. In this study, our focus is on identifying a possible atmospheric pattern that may enhance the transport of black carbon emissions from cropland burning in Russia to the snow-covered Arctic. Specifically, atmospheric blocking events are large-scale patterns in the atmospheric pressure field that are nearly stationary and act to block migratory cyclones. The persistent low-level wind patterns associated with these mid-latitude weather patterns are likely to accelerate potential transport and increase the success of transport of black carbon emissions to the snow-covered Arctic during the spring. Our results revealed that overall, in March, the transport time of hypothetical black carbon emissions from Russian cropland burning to the Arctic snow is shorter (in some areas over 50 hours less at higher injection heights) and the success rate is also much higher (in some areas up to 100% more successful) during atmospheric blocking conditions as compared to conditions without an atmospheric blocking event. The enhanced transport of black carbon has important implications for the efficacy of deposited black carbon. Therefore, understanding these relationships could lead to possible mitigation strategies for reducing the impact of deposition of black carbon from crop residue burning in the Arctic.

Building Better Narratives in Black Education

ERIC Educational Resources Information Center

Anderson, Meredith B. L.

2016-01-01

"Building Better Narratives in Black Education" fundamentally changes the narrative and face of education reform to meaningfully include Black voices, leaders and initiatives that truly have equity and Black student success at the core. This is imperative as there is an education crisis for Black students in the United States. Recent…

Stationary holographic plasma quenches and numerical methods for non-killing horizons.

PubMed

Figueras, Pau; Wiseman, Toby

2013-04-26

We explore use of the harmonic Einstein equations to numerically find stationary black holes where the problem is posed on an ingoing slice that extends into the interior of the black hole. Requiring no boundary conditions at the horizon beyond smoothness of the metric, this method may be applied for horizons that are not Killing. As a nontrivial illustration we find black holes which, via AdS-CFT, describe a time-independent CFT plasma flowing through a static spacetime which asymptotes to Minkowski in the flow's past and future, with a varying spatial geometry in between. These are the first nonperturbative examples of stationary black holes which do not have Killing horizons. When the CFT spacetime slowly varies, the CFT stress tensor derived from gravity is well described by viscous hydrodynamics. For fast variation it is not, and the solutions are stationary analogs of dynamical quenches, with the plasma being suddenly driven out of equilibrium. We find evidence these flows become unstable for sufficiently strong quenches, and speculate the instability may be turbulent.

Gravitational Waves from Stellar Black Hole Binaries and the Impact on Nearby Sun-like Stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lopes, Ilídio; Silk, Joseph, E-mail: ilidio.lopes@tecnico.ulisboa.pt, E-mail: silk@astro.ox.ac.uk

We investigate the impact of resonant gravitational waves on quadrupole acoustic modes of Sun-like stars located nearby stellar black hole binary systems (such as GW150914 and GW151226). We find that the stimulation of the low-overtone modes by gravitational radiation can lead to sizeable photometric amplitude variations, much larger than the predictions for amplitudes driven by turbulent convection, which in turn are consistent with the photometric amplitudes observed in most Sun-like stars. For accurate stellar evolution models, using up-to-date stellar physics, we predict photometric amplitude variations of 1–10{sup 3} ppm for a solar mass star located at a distance between 1more » au and 10 au from the black hole binary and belonging to the same multi-star system. The observation of such a phenomenon will be within the reach of the Plato mission because the telescope will observe several portions of the Milky Way, many of which are regions of high stellar density with a substantial mixed population of Sun-like stars and black hole binaries.« less

Floating rGO-based black membranes for solar driven sterilization.

PubMed

Zhang, Yao; Zhao, Dengwu; Yu, Fan; Yang, Chao; Lou, Jinwei; Liu, Yanming; Chen, Yingying; Wang, Zhongyong; Tao, Peng; Shang, Wen; Wu, Jianbo; Song, Chengyi; Deng, Tao

2017-12-14

This paper presents a new steam sterilization approach that uses a solar-driven evaporation system at the water/air interface. Compared to the conventional solar autoclave, this new steam sterilization approach via interfacial evaporation requires no complex system design to bear high steam pressure. In such a system, a reduced graphene oxide/polytetrafluoroethylene composite membrane floating at the water/air interface serves as a light-to-heat conversion medium to harvest and convert incident solar light into localized heat. Such localized heat raises the temperature of the membrane substantially and helps generate steam with a temperature higher than 120 °C. A sterilization device that takes advantage of the interfacial solar-driven evaporation system was built and its successful sterilization capability was demonstrated through both chemical and biological sterilization tests. The interfacial evaporation-based solar driven sterilization approach offers a potential low cost solution to meet the need for sterilization in undeveloped areas that lack electrical power but have ample solar radiation.

Insight into the microscopic structure of an AdS black hole from a thermodynamical phase transition.

PubMed

Wei, Shao-Wen; Liu, Yu-Xiao

2015-09-11

Comparing with an ordinary thermodynamic system, we investigate the possible microscopic structure of a charged anti-de Sitter black hole completely from the thermodynamic viewpoint. The number density of the black hole molecules is introduced to measure the microscopic degrees of freedom of the black hole. We found that the number density suffers a sudden change accompanied by a latent heat when the black hole system crosses the small-large black hole coexistence curve, while when the system passes the critical point, it encounters a second-order phase transition with a vanishing latent heat due to the continuous change of the number density. Moreover, the thermodynamic scalar curvature suggests that there is a weak attractive interaction between two black hole molecules. These phenomena might cast new insight into the underlying microscopic structure of a charged anti-de Sitter black hole.

Deposition pattern and throughfall fluxes in secondary cool temperate forest, South Korea

NASA Astrophysics Data System (ADS)

Kumar Gautam, Mukesh; Lee, Kwang-Sik; Song, Byeong-Yeol

2017-07-01

Chemistry and deposition fluxes in the rainfall and throughfall of red pine (Pinus densiflora), black locust (Robinia pseudoacacia), and chestnut (Castanea crenata) monocultures, and mixed red pine-black locust-chestnut stands were examined in a nutrient-limited cool temperate forest of central South Korea. Throughfall was enriched in both basic and acidic constituents relative to rainfall, suggesting that both dry deposition and canopy leaching are important sources of throughfall constituents. Net throughfall fluxes (NTFs) of cations and anions significantly differed among four different stands as well as seasonally. Red pine exhibited highest fluxes (TF and NTF) for Ca2+, black locust for K+, mixed stands for Mg2+, and chestnut for Na+. In contrast, NTF of SO42-, NO3-, and NH4+was highest in the red pine, intermediate in the chestnut and mixed stands, and lowest in the black locust. In general, canopy uptake of H+ and NH4+ for all stands was higher in summer than in winter. Dry deposition appears to play a major role in atmospheric deposition to this cool temperate forest, especially in summer. Dry deposition for both cations and anions displayed high spatial variability, even though stands were adjacent to one another and experienced identical atmospheric deposition loads. Canopy leaching of K+ (95-78% of NTF), Mg2+ (92-23% of NTF), and Ca2+ (91-12% of NTF) was highest for the black locust, lowest for chestnut, and intermediate for the red pine and mixed stands. The present study documented significant changes in throughfall chemistry and NTF among different forest stands, which presumably be related with the differences in the canopy characteristics and differences in their scavenging capacity for dry deposition and canopy exchange. Difference in the canopy retention of H+ and base cation leaching suggests that canopy exchange was mainly driven by weak acid excretion and lesser by H+ exchange reaction. Our results indicate that despite a high base cation deposition, a combination of higher input of acidifying constituents, low soil pH, and total acidic deposition approaching South Korean critical loads make regional forest vulnerable to acidification.

Grad Students Talk: Development and Process of a Student-Led Social Justice Initiative

ERIC Educational Resources Information Center

Lantz, Melanie M.; Fix, Rebecca L.; Davis, Brittan L.; Harrison, Leighna N.; Oliver, Ashley; Crowell, Candice; Mitchell, Amanda M.; García, James J.

2016-01-01

College student activism has long been a staple of campus life, often driven by the sociopolitical issues of the time. In response to recent and continuous violent deaths of members of the Black community, rising instances of overt racism, and perceived silence among our institutes and professional groups, a multiinstitutional and diverse…

An XCP User’s Guide and Reference Manual

DTIC Science & Technology

1993-08-01

Sanford, and J. R. Haustein , 1985: Observing hurricane-driven waves and currents, Proc. 17th Annual Offshore Technology Conference, OTC 4934, 331-339...of Washington, Seattle, IWA, 164 pp. I 3 TR 9309 A3 I I Sanford, T. B., P. G. Black, J. R. Haustein , J. W. Feeney, G. Z. Forristall, and J. F. Price

Social and Emotional Learning and Equity in School Discipline

ERIC Educational Resources Information Center

Gregory, Anne; Fergus, Edward

2017-01-01

Beginning as early as preschool, race and gender are intertwined with the way US schools mete out discipline. In particular, black students and male students are much more likely than others to be suspended or expelled--punishments that we know can hold them back academically. These disparities, and the damage they can cause, have driven recent…

Dual Optical Comb LWIR Source and Sensor

DTIC Science & Technology

2017-10-12

Figure 39. Locking loop only controls one parameter, whereas there are two free- running parameters to control...optical frequency, along with a 12 point running average (black) equivalent to a 4 cm -1 resolution. .............................. 52 Figure 65...and processed on a single epitaxial substrate. Each OFC will be electrically driven and free- running (requiring no optical locking mechanisms). This

Professional Development for Culturally Responsive and Relationship-Based Pedagogy. Black Studies and Critical Thinking. Volume 24

ERIC Educational Resources Information Center

Sleeter, Christine E., Ed.

2011-01-01

The work presented here is a large-scale evaluation of a theory-driven school reform project in New Zealand, which focuses on improving the educational achievement of Maori students in public secondary schools. The project's conceptual underpinnings are based on Kaupapa Maori research, culturally responsive teaching, student voice, and…

Circumpolar dynamics of a marine top-predator track ocean warming rates.

PubMed

Descamps, Sébastien; Anker-Nilssen, Tycho; Barrett, Robert T; Irons, David B; Merkel, Flemming; Robertson, Gregory J; Yoccoz, Nigel G; Mallory, Mark L; Montevecchi, William A; Boertmann, David; Artukhin, Yuri; Christensen-Dalsgaard, Signe; Erikstad, Kjell-Einar; Gilchrist, H Grant; Labansen, Aili L; Lorentsen, Svein-Håkon; Mosbech, Anders; Olsen, Bergur; Petersen, Aevar; Rail, Jean-Francois; Renner, Heather M; Strøm, Hallvard; Systad, Geir H; Wilhelm, Sabina I; Zelenskaya, Larisa

2017-09-01

Global warming is a nonlinear process, and temperature may increase in a stepwise manner. Periods of abrupt warming can trigger persistent changes in the state of ecosystems, also called regime shifts. The responses of organisms to abrupt warming and associated regime shifts can be unlike responses to periods of slow or moderate change. Understanding of nonlinearity in the biological responses to climate warming is needed to assess the consequences of ongoing climate change. Here, we demonstrate that the population dynamics of a long-lived, wide-ranging marine predator are associated with changes in the rate of ocean warming. Data from 556 colonies of black-legged kittiwakes Rissa tridactyla distributed throughout its breeding range revealed that an abrupt warming of sea-surface temperature in the 1990s coincided with steep kittiwake population decline. Periods of moderate warming in sea temperatures did not seem to affect kittiwake dynamics. The rapid warming observed in the 1990s may have driven large-scale, circumpolar marine ecosystem shifts that strongly affected kittiwakes through bottom-up effects. Our study sheds light on the nonlinear response of a circumpolar seabird to large-scale changes in oceanographic conditions and indicates that marine top predators may be more sensitive to the rate of ocean warming rather than to warming itself. © 2017 John Wiley & Sons Ltd.

Recent Increase in Black Carbon Concentrations from a Mt. Everest Ice Core Spanning 1860-2000 AD

NASA Astrophysics Data System (ADS)

Kaspari, S.; Schwikowski, M.; Gysel, M.; Mayewski, P. A.; Kang, S.; Hou, S.

2009-12-01

Black carbon produced by the incomplete combustion of biomass, coal and diesel fuels can significantly contribute to climate change by altering the Earth’s radiative balance. Black carbon in the atmosphere absorbs light and causes atmospheric heating, whereas black carbon deposited on snow and ice can significantly reduce the surface albedo, resulting in rapid melting of snow and ice. Historical records of black carbon concentration and distribution in the atmosphere are needed to determine the role of black carbon in climate change, however most studies have relied on estimated inventories based on wood and/or fossil fuel consumption data. Reconstructing black carbon concentrations in Asia is particularly important because this region has some of the largest black carbon sources globally, which negatively impact climate, water resources, agriculture and human health. We analyzed a Mt. Everest ice core for black carbon using a single particle soot photometer (SP2). The high-resolution black carbon data demonstrates strong seasonality, with peak concentrations during the winter-spring, and low concentrations during the summer monsoon season. Black carbon concentrations from 1975-2000 relative to 1860-1975 have increased approximately threefold, and the timing of this increase is consistent with black carbon emission inventory data from South Asia. It is notable that there is no increasing trend in iron (used as a proxy for dust) since 1860. This is significant because it suggests that if the recent retreat of glaciers in the region is due, at least in part, to the effect of impurities on snow albedo, the reduced albedo is due to changes in black carbon emissions, not dust.

The Dialectical Problematic of Resolving the Black-White Academic Achievement Gap and Climate Change

ERIC Educational Resources Information Center

Mocombe, Paul C.

2018-01-01

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

The Core Journal Concept in Black Studies

ERIC Educational Resources Information Center

Weissinger, Thomas

2010-01-01

Black Studies scholars have shown interest in the core journal concept. Indeed, the idea of core journals for the study of the Black experience has changed several times since 1940. While Black Studies scholars are citing Black Studies journals with frequency, they also cite traditional disciplinary journals a great deal of the time. However,…

Passively Q-switched wavelength-tunable 1-μm fiber lasers with tapered-fiber-based black phosphorus saturable absorbers

NASA Astrophysics Data System (ADS)

Song, Huaqing; Wang, Qi; Wang, Dongdong; Li, Li

2018-03-01

In this paper, we demonstrated passively Q-switched wavelength-tunable 1-μm fiber lasers utilizing few-layer black phosphorus saturable absorbers. The few-layer BP was deposited onto the tapered fibers by an optically driven process. The wavelength tunability was achieved with a fiber Sagnac loop comprised of a piece of polarization maintaining fiber and a polarization controller. Stable Q-switching laser operations were observed at wavelengths ranging from 1040.5 to 1044.6 nm at threshold pump power of 220 mW. Maximal pulse energy of 141.27 nJ at a repetition rate of 63 kHz was recorded under pump power of 445 mW.

Caregivers' psychosocial factors underlying sugar-sweetened beverage intake among non-Hispanic black preschoolers: an elicitation study.

PubMed

Tipton, Julia A

2014-01-01

The purpose of this study was to explore caregivers' beliefs and perceptions regarding serving sugar-sweetened beverages (SSBs) to non-Hispanic black preschoolers. The Theory of Planned Behavior (TpB) was used as the framework for conducting elicitation interviews among a sample of (n = 19) caregivers. Thematic coding of interview transcripts revealed that the decision to serve SSBs to preschoolers is driven by numerous individual, familial, cultural, and environmental factors. Salient factors associated with serving SSBs included convenience, cost, taste, potential health consequences, availability, and pressure from other parents. Population-specific interventions aimed at reducing SSB intake among non-Hispanic preschoolers are discussed. © 2013.

Assessing Racial/Ethnic Disparities in Treatment across Episodes of Mental Health Care

PubMed Central

Cook, Benjamin Lê; Zuvekas, Samuel H; Carson, Nicholas; Wayne, Geoffrey Ferris; Vesper, Andrew; McGuire, Thomas G

2014-01-01

ObjectiveTo investigate disparities in mental health care episodes, aligning our analyses with decisions to start or drop treatment, and choices made during treatment. Study DesignWe analyzed whites, blacks, and Latinos with probable mental illness from Panels 9–13 of the Medical Expenditure Panel Survey, assessing disparities at the beginning, middle, and end of episodes of care (initiation, adequate care, having an episode with only psychotropic drug fills, intensity of care, the mixture of primary care provider (PCP) and specialist visits, use of acute psychiatric care, and termination). FindingsCompared with whites, blacks and Latinos had less initiation and adequacy of care. Black and Latino episodes were shorter and had fewer psychotropic drug fills. Black episodes had a greater proportion of specialist visits and Latino episodes had a greater proportion of PCP visits. Blacks were more likely to have an episode with acute psychiatric care. ConclusionsDisparities in adequate care were driven by initiation disparities, reinforcing the need for policies that improve access. Many episodes were characterized only by psychotropic drug fills, suggesting inadequate medication guidance. Blacks’ higher rate of specialist use contradicts previous studies and deserves future investigation. Blacks’ greater acute mental health care use raises concerns over monitoring of their treatment. PMID:23855750

Black hole thermalization, D0 brane dynamics, and emergent spacetime

NASA Astrophysics Data System (ADS)

Riggins, Paul; Sahakian, Vatche

2012-08-01

When matter falls past the horizon of a large black hole, the expectation from string theory is that the configuration thermalizes and the information in the probe is rather quickly scrambled away. The traditional view of a classical unique spacetime near a black hole horizon conflicts with this picture. The question then arises as to what spacetime does the probe actually see as it crosses a horizon, and how does the background geometry imprint its signature onto the thermal properties of the probe. In this work, we explore these questions through an extensive series of numerical simulations of D0 branes. We determine that the D0 branes quickly settle into an incompressible symmetric state—thermalized within a few oscillations through a process driven entirely by internal nonlinear dynamics. Surprisingly, thermal background fluctuations play no role in this mechanism. Signatures of the background fields in this thermal state arise either through fluxes, i.e. black hole hair; or if the probe expands to the size of the horizon—which we see evidence of. We determine simple scaling relations for the D0 branes’ equilibrium size, time to thermalize, lifetime, and temperature in terms of their number, initial energy, and the background fields. Our results are consistent with the conjecture that black holes are the fastest scramblers as seen by matrix theory.

Racial Survival Disparity in Head and Neck Cancer Results from Low Prevalence of Human Papillomavirus Infection in Black Oropharyngeal Cancer Patients

PubMed Central

Settle, Kathleen; Posner, Marshall R.; Schumaker, Lisa M.; Tan, Ming; Suntharalingam, Mohan; Goloubeva, Olga; Strome, Scott E.; Haddad, Robert I.; Patel, Shital S.; Cambell, Earl V.; Sarlis, Nicholas; Lorch, Jochen; Cullen, Kevin J.

2015-01-01

The burden of squamous cell carcinoma of the head and neck (SCCHN) is greater for blacks than for whites, especially in oropharyngeal cases. We previously showed retrospectively that disease-free survival was significantly greater in white than in black SCCHN patients treated with chemoradiation, the greatest difference occurring in the oropharyngeal subgroup. Oropharyngeal cancer is increasing in incidence and in its association with human papillomavirus (HPV) infection; HPV-positive oropharyngeal cancer patients have significantly better outcomes (versus HPV-negative). These collective data led to the present analyses of overall survival (OS) in our retrospective cohort and of OS and HPV status (tested prospectively in pretreatment biopsy specimens) in the phase 3, multicenter TAX 324 trial of induction chemotherapy followed by concurrent chemoradiation in SCCHN patients. Median OS in the retrospective cohort of 106 white and 95 black SCCHN patients was 52.1 months (white) versus only 23.7 months (black; P = 0.009), due entirely to OS in the subgroup of patients with oropharyngeal cancer—69.4 months (whites) versus 25.2 months (blacks; P = 0.0006); no significant difference by race occurred in survival of non-oropharyngeal SCCHN (P = 0.58). In TAX 324, 196 white patients and 28 black patients could be assessed for HPV status. Median OS was significantly worse for black patients (20.9 months) than for white patients (70.6 months; P = 0.03) and dramatically improved in HPV-positive (not reached) versus HPV-negative (26.6 months, 5.1 hazard ratio) oropharyngeal patients (P < 0.0001), 49% of whom were HPV-16 positive. Overall, HPV positivity was 34% in white versus 4% in black patients (P = 0.0004). Survival was similar for black and white HPV-negative patients (P = 0.56). This is the first prospective assessment of confirmed HPV status in black versus white SCCHN patients. Worse OS for black SCCHN patients was driven by oropharyngeal cancer outcomes, and that for black oropharyngeal cancer patients by a lower prevalence of HPV infection. These findings have important implications for the etiology, prevention, prognosis, and treatment of SCCHN. PMID:19641042

Racial survival disparity in head and neck cancer results from low prevalence of human papillomavirus infection in black oropharyngeal cancer patients.

PubMed

Settle, Kathleen; Posner, Marshall R; Schumaker, Lisa M; Tan, Ming; Suntharalingam, Mohan; Goloubeva, Olga; Strome, Scott E; Haddad, Robert I; Patel, Shital S; Cambell, Earl V; Sarlis, Nicholas; Lorch, Jochen; Cullen, Kevin J

2009-09-01

The burden of squamous cell carcinoma of the head and neck (SCCHN) is greater for blacks than for whites, especially in oropharyngeal cases. We previously showed retrospectively that disease-free survival was significantly greater in white than in black SCCHN patients treated with chemoradiation, the greatest difference occurring in the oropharyngeal subgroup. Oropharyngeal cancer is increasing in incidence and in its association with human papillomavirus (HPV) infection; HPV-positive oropharyngeal cancer patients have significantly better outcomes (versus HPV-negative). These collective data led to the present analyses of overall survival (OS) in our retrospective cohort and of OS and HPV status (tested prospectively in pretreatment biopsy specimens) in the phase 3, multicenter TAX 324 trial of induction chemotherapy followed by concurrent chemoradiation in SCCHN patients. Median OS in the retrospective cohort of 106 white and 95 black SCCHN patients was 52.1 months (white) versus only 23.7 months (black; P = 0.009), due entirely to OS in the subgroup of patients with oropharyngeal cancer--69.4 months (whites) versus 25.2 months (blacks; P = 0.0006); no significant difference by race occurred in survival of non-oropharyngeal SCCHN (P = 0.58). In TAX 324, 196 white patients and 28 black patients could be assessed for HPV status. Median OS was significantly worse for black patients (20.9 months) than for white patients (70.6 months; P = 0.03) and dramatically improved in HPV-positive (not reached) versus HPV-negative (26.6 months, 5.1 hazard ratio) oropharyngeal patients (P < 0.0001), 49% of whom were HPV-16 positive. Overall, HPV positivity was 34% in white versus 4% in black patients (P = 0.0004). Survival was similar for black and white HPV-negative patients (P = 0.56). This is the first prospective assessment of confirmed HPV status in black versus white SCCHN patients. Worse OS for black SCCHN patients was driven by oropharyngeal cancer outcomes, and that for black oropharyngeal cancer patients by a lower prevalence of HPV infection. These findings have important implications for the etiology, prevention, prognosis, and treatment of SCCHN.

Stress, sex, and plague: Patterns of developmental stress and survival in pre- and post-Black Death London.

PubMed

DeWitte, Sharon N

2018-01-01

Previous research revealed declines in survivorship in London before the Black Death (c. 1346-1353), and improvements in survivorship following the epidemic. These trends indicate that there were declines in general levels of health before the Black Death and improvements thereof afterwards. This study expands on previous research by examining whether changes in survivorship were consistent between the sexes, and how patterns of developmental stress markers changed before and after the Black Death. This study uses samples from London cemeteries dated to one of three periods: Early Pre-Black Death (1000-1200 AD, n = 255), Late Pre-Black Death (1200-1250 AD, n = 247), or Post-Black Death (1350-1540 AD n = 329). Temporal trends in survivorship are assessed via Kaplan-Meier survival analysis, and trends in tibial length (as a proxy for stature) and linear enamel hypoplasia (LEH) are assessed using t-tests and Chi-square tests, respectively. Survivorship for both sexes decreased before the Black Death and increased afterwards. For males, LEH frequencies increased and stature decreased before the epidemic, and LEH declined and stature increased after the Black Death. For females, the only significant change with respect to developmental stress markers was a decrease in stature after the Black Death. These results might reflect variation between the sexes in sensitivity to stressors, the effects of nutrition on pubertal timing, disproportionate access to dietary resources for males in the aftermath of the Black Death, the disproportionate deaths of frail individuals during the epidemic, or some combination of these factors. © 2017 Wiley Periodicals, Inc.

Biotic interactions mediate the expansion of black mangrove (Avicennia germinans) into salt marshes under climate change.

PubMed

Guo, Hongyu; Zhang, Yihui; Lan, Zhenjiang; Pennings, Steven C

2013-09-01

Many species are expanding their distributions to higher latitudes due to global warming. Understanding the mechanisms underlying these distribution shifts is critical for better understanding the impacts of climate changes. The climate envelope approach is widely used to model and predict species distribution shifts with changing climates. Biotic interactions between species, however, may also influence species distributions, and a better understanding of biotic interactions could improve predictions based solely on climate envelope models. Along the northern Gulf of Mexico coast, USA, subtropical black mangrove (Avicennia germinans) at the northern limit of its distribution grows sympatrically with temperate salt marsh plants in Florida, Louisiana, and Texas. In recent decades, freeze-free winters have led to an expansion of black mangrove into salt marshes. We examined how biotic interactions between black mangrove and salt marsh vegetation along the Texas coast varied across (i) a latitudinal gradient (associated with a winter-temperature gradient); (ii) the elevational gradient within each marsh (which creates different marsh habitats); and (iii) different life history stages of black mangroves (seedlings vs. juvenile trees). Each of these variables affected the strength or nature of biotic interactions between black mangrove and salt marsh vegetation: (i) Salt marsh vegetation facilitated black mangrove seedlings at their high-latitude distribution limit, but inhibited black mangrove seedlings at lower latitudes; (ii) mangroves performed well at intermediate elevations, but grew and survived poorly in high- and low-marsh habitats; and (iii) the effect of salt marsh vegetation on black mangroves switched from negative to neutral as black mangroves grew from seedlings into juvenile trees. These results indicate that the expansion of black mangroves is mediated by complex biotic interactions. A better understanding of the impacts of climate change on ecological communities requires incorporating context-dependent biotic interactions into species range models. © 2013 John Wiley & Sons Ltd.

Quasars Outflows As A Function of SED - An Empirical Approach

NASA Astrophysics Data System (ADS)

Richmond, Joseph M.; Ganguly, Rajib

2015-08-01

Feedback from quasars (jets, outflows, and luminosity) is now recognized as a vital phase in describing galaxy evolution, growth, and star formation efficiency. Regarding outflows, roughly 60% are observed to have outflowing gas appearing at large velocities and with a variety of velocity dispersions. The most extreme observed form of these outflows appears in the ultraviolet spectrum of 15-20% of objects. Understanding the physics of these outflows is important for both astrophysical and cosmological reasons. Establishing empirical relationships to test the theoretical models of how these outflows are driven (and hence, how they impact their surroundings) is currently plagued by having too few objects, where other parameters like the black hole mass or accretion rate, may add to the scatter. We aim to fix this by using a systematic study of a large sample of objects. As a follow up to a previous study, we have identified a sample of nearly 11000 z=1.7-2 quasars using archived data from the Sloan Digital Sky Survey (Data Release 7), of which roughly 4400 appear to show outflows according to the visual inspection. The specific redshift range is chosen to feature both the Mg II 2800 emission line as well as wavelengths extending to nearly 20,000 km/s blueward of the C IV 1549 emission line. Our goals for this study are: (1) To temper our visual inspection schemes with a more automated, computer-driven scheme; (2) To measure the properties of the outflows (velocity, velocity dispersion, equivalent width, ionization); (3) To supplement the SDSS spectra with photometric measurements from GALEX, 2MASS, and WISE to further characterize the spectral energy distributions (SEDs) and dust content; (4) To form spectral composites to investigate possible SED changes with outflow properties; and (5) To use published estimates of the quasar physical properties (black hole mass, accretion rate, etc.) to fully establish in an empirical way the complex dependencies between the properties of the outflow, and the physical properties of the system.

Fuzzy spaces topology change and BH thermodynamics

NASA Astrophysics Data System (ADS)

Silva, C. A. S.; Landim, R. R.

2014-03-01

What is the ultimate fate of something that falls into a black hole? From this question arises one of the most intricate problems of modern theoretical physics: the black hole information loss paradox. Bekenstein and Hawking have been shown that the entropy in a black hole is proportional to the surface area of its event horizon, which should be quantized in a multiple of the Planck area. This led G.'t Hooft and L. Susskind to propose the holographic principle which states that all the information inside the black hole can be stored on its event horizon. From this results, one may think if the solution to the information paradox could lies in the quantum properties of the black hole horizon. One way to quantize the event horizon is to see it as a fuzzy sphere, which posses a closed relation with Hopf algebras. This relation makes possible a topology change process where a fuzzy sphere splits in two others. In this work it will be shown that, if one quantize the black hole event horizon as a fuzzy sphere taking into account its quantum symmetry properties, a topology change process to black holes can be defined without break unitarity or locality, and we can obtain a possible solution to the information paradox. Moreover, we show that this model can explain the origin of the black hole entropy, and why black holes obey a generalized second law of thermodynamics.

An Indirect Technique for the Measurement of Changes in Black Identity

ERIC Educational Resources Information Center

Condie, J. Spencer; Christiansen, James W.

1977-01-01

In order to indirectly measure the impact of the black power movement in terms of any shifts in identity and self-concept within the black community a content analysis was made of 272 issues of "Ebony" magazine published between January, 1949 and December, 1972 to determine any significant changes in the number of advertisements for cosmetics.…

Will the Effects of Sea-Level Rise Create Ecological Traps for Pacific Island Seabirds?

PubMed

Reynolds, Michelle H; Courtot, Karen N; Berkowitz, Paul; Storlazzi, Curt D; Moore, Janet; Flint, Elizabeth

2015-01-01

More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2). However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR) and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled inundation and wave-driven flooding of a globally important seabird rookery in the subtropical Pacific. We acquired new high-resolution Digital Elevation Models (DEMs) and used the Delft3D wave model and ArcGIS to model wave heights and inundation for a range of SLR scenarios (+0.5, +1.0, +1.5, and +2.0 m) at Midway Atoll. Next, we classified vegetation to delineate habitat exposure to inundation and identified how breeding phenology, colony synchrony, and life history traits affect species-specific sensitivity. We identified 3 of 13 species as highly vulnerable to SLR in the Hawaiian Islands and quantified their atoll-wide distribution (Laysan albatross, Phoebastria immutabilis; black-footed albatross, P. nigripes; and Bonin petrel, Pterodroma hypoleuca). Our models of wave-driven flooding forecast nest losses up to 10% greater than passive inundation models at +1.0 m SLR. At projections of + 2.0 m SLR, approximately 60% of albatross and 44% of Bonin petrel nests were overwashed displacing more than 616,400 breeding albatrosses and petrels. Habitat loss due to passive SLR may decrease the carrying capacity of some islands to support seabird colonies, while sudden high-water events directly reduce survival and reproduction. This is the first study to simulate wave-driven flooding and the combined impacts of SLR, groundwater rise, and storm waves on seabird colonies. Our results highlight the need for early climate change planning and restoration of higher elevation seabird refugia to prevent low-lying protected islands from becoming ecological traps in the face of rising sea levels.

Will the effects of sea-level rise create ecological traps for Pacific Island seabirds?

USGS Publications Warehouse

Reynolds, Michelle H.; Courtot, Karen; Berkowitz, Paul; Storlazzi, Curt; Moore, Janet; Flint, Elizabeth

2015-01-01

More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2). However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR) and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled inundation and wave-driven flooding of a globally important seabird rookery in the subtropical Pacific. We acquired new high-resolution Digital Elevation Models (DEMs) and used the Delft3D wave model and ArcGIS to model wave heights and inundation for a range of SLR scenarios (+0.5, +1.0, +1.5, and +2.0 m) at Midway Atoll. Next, we classified vegetation to delineate habitat exposure to inundation and identified how breeding phenology, colony synchrony, and life history traits affect species-specific sensitivity. We identified 3 of 13 species as highly vulnerable to SLR in the Hawaiian Islands and quantified their atoll-wide distribution (Laysan albatross, Phoebastria immutabilis; black-footed albatross, P. nigripes; and Bonin petrel, Pterodroma hypoleuca). Our models of wave-driven flooding forecast nest losses up to 10% greater than passive inundation models at +1.0 m SLR. At projections of + 2.0 m SLR, approximately 60% of albatross and 44% of Bonin petrel nests were overwashed displacing more than 616,400 breeding albatrosses and petrels. Habitat loss due to passive SLR may decrease the carrying capacity of some islands to support seabird colonies, while sudden high-water events directly reduce survival and reproduction. This is the first study to simulate wave-driven flooding and the combined impacts of SLR, groundwater rise, and storm waves on seabird colonies. Our results highlight the need for early climate change planning and restoration of higher elevation seabird refugia to prevent low-lying protected islands from becoming ecological traps in the face of rising sea levels.

Will the Effects of Sea-Level Rise Create Ecological Traps for Pacific Island Seabirds?

PubMed Central

Reynolds, Michelle H.; Courtot, Karen N.; Berkowitz, Paul; Storlazzi, Curt D.; Moore, Janet; Flint, Elizabeth

2015-01-01

More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2). However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR) and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled inundation and wave-driven flooding of a globally important seabird rookery in the subtropical Pacific. We acquired new high-resolution Digital Elevation Models (DEMs) and used the Delft3D wave model and ArcGIS to model wave heights and inundation for a range of SLR scenarios (+0.5, +1.0, +1.5, and +2.0 m) at Midway Atoll. Next, we classified vegetation to delineate habitat exposure to inundation and identified how breeding phenology, colony synchrony, and life history traits affect species-specific sensitivity. We identified 3 of 13 species as highly vulnerable to SLR in the Hawaiian Islands and quantified their atoll-wide distribution (Laysan albatross, Phoebastria immutabilis; black-footed albatross, P. nigripes; and Bonin petrel, Pterodroma hypoleuca). Our models of wave-driven flooding forecast nest losses up to 10% greater than passive inundation models at +1.0 m SLR. At projections of + 2.0 m SLR, approximately 60% of albatross and 44% of Bonin petrel nests were overwashed displacing more than 616,400 breeding albatrosses and petrels. Habitat loss due to passive SLR may decrease the carrying capacity of some islands to support seabird colonies, while sudden high-water events directly reduce survival and reproduction. This is the first study to simulate wave-driven flooding and the combined impacts of SLR, groundwater rise, and storm waves on seabird colonies. Our results highlight the need for early climate change planning and restoration of higher elevation seabird refugia to prevent low-lying protected islands from becoming ecological traps in the face of rising sea levels. PMID:26398209

Global Warming in the Twenty-First Century: An Alternative Scenario

NASA Technical Reports Server (NTRS)

Hansen, James; Sato, Makiko; Ruedy, Reto; Lacis, Andrew; Oinas, Valdar; Travis, Larry (Technical Monitor)

2000-01-01

A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO2 greenhouse gases (GHGs), such as chlorofluorocarbons, CH4, and N2O, not by the products of fossil fuel burning, CO2 and aerosols, the positive and negative climate forcings of which are partially offsetting. The growth rate of non-CO2 GHGs has declined in the past decade. If sources of CH4 and O3 precursors were reduced in the future, the change in climate forcing by non-CO2 GHGs in the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO2 emissions, this reduction of non-CO2 GHGs could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition specific long-term global monitoring of aerosol properties.

Global warming in the twenty-first century: an alternative scenario.

PubMed

Hansen, J; Sato, M; Ruedy, R; Lacis, A; Oinas, V

2000-08-29

A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO(2) greenhouse gases (GHGs), such as chlorofluorocarbons, CH(4), and N(2)O, not by the products of fossil fuel burning, CO(2) and aerosols, the positive and negative climate forcings of which are partially offsetting. The growth rate of non-CO(2) GHGs has declined in the past decade. If sources of CH(4) and O(3) precursors were reduced in the future, the change in climate forcing by non-CO(2) GHGs in the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO(2) emissions, this reduction of non-CO(2) GHGs could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition-specific long-term global monitoring of aerosol properties.

Global warming in the twenty-first century: An alternative scenario

PubMed Central

Hansen, James; Sato, Makiko; Ruedy, Reto; Lacis, Andrew; Oinas, Valdar

2000-01-01

A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO2 greenhouse gases (GHGs), such as chlorofluorocarbons, CH4, and N2O, not by the products of fossil fuel burning, CO2 and aerosols, the positive and negative climate forcings of which are partially offsetting. The growth rate of non-CO2 GHGs has declined in the past decade. If sources of CH4 and O3 precursors were reduced in the future, the change in climate forcing by non-CO2 GHGs in the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO2 emissions, this reduction of non-CO2 GHGs could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition-specific long-term global monitoring of aerosol properties. PMID:10944197

Black garlic: A critical review of its production, bioactivity, and application.

PubMed

Kimura, Shunsuke; Tung, Yen-Chen; Pan, Min-Hsiung; Su, Nan-Wei; Lai, Ying-Jang; Cheng, Kuan-Chen

2017-01-01

Black garlic is obtained from fresh garlic (Allium sativum L.) that has been fermented for a period of time at a controlled high temperature (60-90°C) under controlled high humidity (80-90%). When compared with fresh garlic, black garlic does not release a strong offensive flavor owing to the reduced content of allicin. Enhanced bioactivity of black garlic compared with that of fresh garlic is attributed to its changes in physicochemical properties. Studies concerning the fundamental findings of black garlic, such as its production, bioactivity, and applications, have thus been conducted. Several types of black garlic products are also available in the market with a fair selling volume. In this article, we summarize the current knowledge of changes in the components, bioactivity, production, and applications of black garlic, as well as the proposed future prospects on their possible applications as a functional food product. Copyright © 2016. Published by Elsevier B.V.

An Academic Innovation: The Executive Ph.D. in Urban Higher Education at a Historically Black University

ERIC Educational Resources Information Center

Stevenson, Joseph Martin; Payne, Alfredda Hunt

2016-01-01

This chapter describes how data analysis and data-driven decision making were critical for designing, developing, and assessing a new academic program. The authors--one, the program's founder; the other, an alumna--begin by highlighting some of the elements in the program's incubation and, subsequently, describe some of the components for data…

HIV Testing Patterns among Urban YMSM of Color

ERIC Educational Resources Information Center

Leonard, Noelle R.; Rajan, Sonali; Gwadz, Marya V.; Aregbesola, Temi

2014-01-01

The heightened level of risk for HIV infection among Black and Latino young men who have sex with men (YMSM) is driven by multilevel influences. Using cross-sectional data, we examined HIV testing patterns among urban YMSM of color in a high-HIV seroprevalence area (ages 16 to 21 years). Self-reported frequency of testing was high, with 42% of…

Bright Merger-nova Emission Powered by Magnetic Wind from a Newborn Black Hole

NASA Astrophysics Data System (ADS)

Ma, Shuai-Bing; Lei, Wei-Hua; Gao, He; Xie, Wei; Chen, Wei; Zhang, Bing; Wang, Ding-Xiong

2018-01-01

Mergers of neutron star–neutron star (NS–NS) or neutron star–black hole (NS–BH) binaries are candidate sources of gravitational waves (GWs). At least a fraction of the merger remnants should be a stellar mass BH with sub-relativistic ejecta. A collimated jet is launched via the Blandford–Znajek mechanism from the central BH to trigger a short gamma-ray burst (sGRB). At the same time, a near-isotropic wind may be driven by the Blandford–Payne mechanism (BP). In previous work, additional energy injection to the ejecta from the BP mechanism was ignored, and radioactive decay has long been thought to be the main source of the kilonova energy. In this Letter, we propose that the wind driven by the BP mechanism from the newborn BH’s disk can heat up and push the ejecta during the prompt emission phase or even at late times when there is fall-back accretion. Such a BP-powered merger-nova could be bright in the optical band even for a low-luminosity sGRB. The detection of a GW merger event with a BH clearly identified as a remnant, accompanied by a bright merger-nova, would provide robust confirmation of our model.

Marketing of menthol cigarettes and consumer perceptions

PubMed Central

2011-01-01

In order to more fully understand why individuals smoke menthol cigarettes, it is important to understand the perceptions held by youth and adults regarding menthol cigarettes. Perceptions are driven by many factors, and one factor that can be important is marketing. This review seeks to examine what role, if any, the marketing of menthol cigarettes plays in the formation of consumer perceptions of menthol cigarettes. The available literature suggests that menthol cigarettes may be perceived as safer choices than non-menthol cigarettes. Furthermore, there is significant overlap between menthol cigarette advertising campaigns and the perceptions of these products held by consumers. The marketing of menthol cigarettes has been higher in publications and venues whose target audiences are Blacks/African Americans. Finally, there appears to have been changes in cigarette menthol content over the past decade, which has been viewed by some researchers as an effort to attract different types of smokers. PMID:21624148

Shifts in community size structure drive temperature invariance of secondary production in a stream-warming experiment.

PubMed

Nelson, Daniel; Benstead, Jonathan P; Huryn, Alexander D; Cross, Wyatt F; Hood, James M; Johnson, Philip W; Junker, James R; Gíslason, Gísli M; Ólafsson, Jón S

2017-07-01

A central question at the interface of food-web and climate change research is how secondary production, or the formation of heterotroph biomass over time, will respond to rising temperatures. The metabolic theory of ecology (MTE) hypothesizes the temperature-invariance of secondary production, driven by matched and opposed forces that reduce biomass of heterotrophs while increasing their biomass turnover rate (production : biomass, or P:B) with warming. To test this prediction at the whole community level, we used a geothermal heat exchanger to experimentally warm a stream in southwest Iceland by 3.8°C for two years. We quantified invertebrate community biomass, production, and P : B in the experimental stream and a reference stream for one year prior to warming and two years during warming. As predicted, warming had a neutral effect on community production, but this result was not driven by opposing effects on community biomass and P:B. Instead, warming had a positive effect on both the biomass and production of larger-bodied, slower-growing taxa (e.g., larval black flies, dipteran predators, snails) and a negative effect on small-bodied taxa with relatively high growth rates (e.g., ostracods, larval chironomids). We attribute these divergent responses to differences in thermal preference between small- vs. large-bodied taxa. Although metabolic demand vs. resource supply must ultimately constrain community production, our results highlight the potential for idiosyncratic community responses to warming, driven by variation in thermal preference and body size within regional species pools. © 2017 by the Ecological Society of America.

Black-blood native T1 mapping: Blood signal suppression for reduced partial voluming in the myocardium.

PubMed

Weingärtner, Sebastian; Meßner, Nadja M; Zöllner, Frank G; Akçakaya, Mehmet; Schad, Lothar R

2017-08-01

To study the feasibility of black-blood contrast in native T 1 mapping for reduction of partial voluming at the blood-myocardium interface. A saturation pulse prepared heart-rate-independent inversion recovery (SAPPHIRE) T 1 mapping sequence was combined with motion-sensitized driven-equilibrium (MSDE) blood suppression for black-blood T 1 mapping at 3 Tesla. Phantom scans were performed to assess the T 1 time accuracy. In vivo black-blood and conventional SAPPHIRE T 1 mapping was performed in eight healthy subjects and analyzed for T 1 times, precision, and inter- and intraobserver variability. Furthermore, manually drawn regions of interest (ROIs) in all T 1 maps were dilated and eroded to analyze the dependence of septal T 1 times on the ROI thickness. Phantom results and in vivo myocardial T 1 times show comparable accuracy with black-blood compared to conventional SAPPHIRE (in vivo: black-blood: 1562 ± 56 ms vs. conventional: 1583 ± 58 ms, P = 0.20); Using black-blood SAPPHIRE precision was significantly lower (standard deviation: 133.9 ± 24.6 ms vs. 63.1 ± 6.4 ms, P < .0001), and blood T 1 time measurement was not possible. Significantly increased interobserver interclass correlation coefficient (ICC) (0.996 vs. 0.967, P = 0.011) and similar intraobserver ICC (0.979 vs. 0.939, P = 0.11) was obtained with the black-blood sequence. Conventional SAPPHIRE showed strong dependence on the ROI thickness (R 2 = 0.99). No such trend was observed using the black-blood approach (R 2 = 0.29). Black-blood SAPPHIRE successfully eliminates partial voluming at the blood pool in native myocardial T 1 mapping while providing accurate T 1 times, albeit at a reduced precision. Magn Reson Med 78:484-493, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Cosmic censorship conjecture in Kerr-Sen black hole

NASA Astrophysics Data System (ADS)

Gwak, Bogeun

2017-06-01

The validity of the cosmic censorship conjecture for the Kerr-Sen black hole, which is a solution to the low-energy effective field theory for four-dimensional heterotic string theory, is investigated using charged particle absorption. When the black hole absorbs the particle, the charge on it changes owing to the conserved quantities of the particle. Changes in the black hole are constrained to the equation for the motion of the particle and are consistent with the laws of thermodynamics. Particle absorption increases the mass of the Kerr-Sen black hole to more than that of the absorbed charges such as angular momentum and electric charge; hence, the black hole cannot be overcharged. In the near-extremal black hole, we observe a violation of the cosmic censorship conjecture for the angular momentum in the first order of expansion and the electric charge in the second order. However, considering an adiabatic process carrying the conserved quantities as those of the black hole, we prove the stability of the black hole horizon. Thus, we resolve the violation. This is consistent with the third law of thermodynamics.

Man induced change in community control in the north-western Black Sea: The top-down bottom-up balance.

PubMed

Bănaru, Daniela; Harmelin-Vivien, Mireille; Boudouresque, Charles F

2010-05-01

The present study shows how marine commercial fish food webs dramatically changed in the north-western Black Sea on both pelagic and benthic environments. Fisheries landings, diversity and equitability strongly decreased between 1965-1970 and 2001-2005. Fishes adapted their feeding behaviour to the increasingly low species diversity of the Black Sea communities. Their food web became poor and simplified following the loss of many top predator species and their trophic links. Linkage density, connectivity and Lyapunov stability proxy strongly decreased. The north-western Black Sea system switched from a complex top-down and bottom-up functioning pattern to a dominantly bottom-up functioning pattern. This study contributes to a better understanding of these transformations within the Danube-Black Sea system in the last decades. An attempt is made to relate these changes with river inputs, fisheries and coastal pollution. Copyright 2009 Elsevier Ltd. All rights reserved.

75 FR 65315 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

.... Applicants: Black Hills Power, Inc., Black Hills/Colorado Electric Utility Co, Black Hills Wyoming, LLC, Cheyenne Light, Fuel and Power Company. Description: Updated Market Power Analysis of the Black Hills... LLC submits tariff filing per 35.17(b): Amendment to Market-Based Rate Application Reflecting Change...

Black Hole Paradox Solved By NASA's Chandra

NASA Astrophysics Data System (ADS)

2006-06-01

Black holes are lighting up the Universe, and now astronomers may finally know how. New data from NASA's Chandra X-ray Observatory show for the first time that powerful magnetic fields are the key to these brilliant and startling light shows. It is estimated that up to a quarter of the total radiation in the Universe emitted since the Big Bang comes from material falling towards supermassive black holes, including those powering quasars, the brightest known objects. For decades, scientists have struggled to understand how black holes, the darkest objects in the Universe, can be responsible for such prodigious amounts of radiation. Animation of a Black Hole Pulling Matter from Companion Star Animation of a Black Hole Pulling Matter from Companion Star New X-ray data from Chandra give the first clear explanation for what drives this process: magnetic fields. Chandra observed a black hole system in our galaxy, known as GRO J1655-40 (J1655, for short), where a black hole was pulling material from a companion star into a disk. "By intergalactic standards J1655 is in our backyard, so we can use it as a scale model to understand how all black holes work, including the monsters found in quasars," said Jon M. Miller of the University of Michigan, Ann Arbor, whose paper on these results appears in this week's issue of Nature. Gravity alone is not enough to cause gas in a disk around a black hole to lose energy and fall onto the black hole at the rates required by observations. The gas must lose some of its orbital angular momentum, either through friction or a wind, before it can spiral inward. Without such effects, matter could remain in orbit around a black hole for a very long time. Illustration of Magnetic Fields in GRO J1655-40 Illustration of Magnetic Fields in GRO J1655-40 Scientists have long thought that magnetic turbulence could generate friction in a gaseous disk and drive a wind from the disk that carries angular momentum outward allowing the gas to fall inward. Using Chandra, Miller and his team provided crucial evidence for the role of magnetic forces in the black hole accretion process. The X-ray spectrum, the number of X-rays at different energies, showed that the speed and density of the wind from J1655's disk corresponded to computer simulation predictions for magnetically-driven winds. The spectral fingerprint also ruled out the two other major competing theories to winds driven by magnetic fields. "In 1973, theorists came up with the idea that magnetic fields could drive the generation of light by gas falling onto black holes," said co-author John Raymond of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "Now, over 30 years later, we finally may have convincing evidence." Evidence for Wind in the GRO J1655-40 Spectrum Evidence for Wind in the GRO J1655-40 Spectrum This deeper understanding of how black holes accrete matter also teaches astronomers about other properties of black holes, including how they grow. "Just as a doctor wants to understand the causes of an illness and not merely the symptoms, astronomers try to understand what causes phenomena they see in the Universe," said co-author Danny Steeghs also of the Harvard-Smithsonian Center for Astrophysics. "By understanding what makes material release energy as it falls onto black holes, we may also learn how matter falls onto other important objects." In addition to accretion disks around black holes, magnetic fields may play an important role in disks detected around young sun-like stars where planets are forming, as well as ultra-dense objects called neutron stars. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center, Cambridge, Mass. Additional information and images can be found at: http://chandra.harvard.edu and http://chandra.nasa.gov

A Historical Analysis of the Contributions of the Black Power Movement to Higher Education: 1960 - 1980

ERIC Educational Resources Information Center

Sokoya, Kinaya

2014-01-01

The purpose of this research was to study the link between the Black Power Movement and changes that occurred in higher education between 1960 and 1980. The main research question study was, "What effect did the Black Power Movement have on changes in higher education from 1960-1980?" The intent of this historical research is to…

Trends in Childhood Leukemia Incidence Over Two Decades from 1992–2013

PubMed Central

Barrington-Trimis, Jessica L.; Cockburn, Myles; Metayer, Catherine; Gauderman, W. James; Wiemels, Joseph; McKean-Cowdin, Roberta

2017-01-01

Incidence rates of childhood leukemia in the United States have steadily increased over the last several decades, but only recently have disparities in the increase in incidence been recognized. In the current analysis, Surveillance, Epidemiology and End Results (SEER) data were used to evaluate recent trends in the incidence of childhood leukemia diagnosed at age 0–19 years from 1992–2013, overall and by age, race/ethnicity, gender, and histologic subtype. Hispanic White children were more likely than non-Hispanic White, non-Hispanic Black or non-Hispanic Asian children to be diagnosed with acute lymphocytic leukemia (ALL) from 2009–2013. From 1992–2013, a significant increase in ALL incidence was observed for Hispanic White children (annual percent change (APC)Hispanic=1.08, 95%CI:0.59, 1.58); no significant increase was observed for non-Hispanic White, Black or Asian children. ALL incidence increased by about 3% per year from 1992–2013 for Hispanic White children diagnosed from 15–19 years (APC=2.67; 95%CI:0.88, 4.49), and by 2% for those 10–14 years (APC=2.09; 95%CI:0.57, 3.63), while no significant increases in incidence were observed in non-Hispanic White, Black, or Asian children of the same age. Acute myeloid leukemia (AML) incidence increased among non-Hispanic White children under 1 year at diagnosis, and among Hispanic White children diagnosed at age 1–4. The increase in incidence rates of childhood ALL appears to be driven by rising rates in older Hispanic children (10–14, and 15–19 years). Future studies are needed to evaluate reasons for the increase in ALL among older Hispanic children. PMID:27778348

Biblical Faith, Ethics and the Quality of Life Quest among Black Americans: Implications for Research.

ERIC Educational Resources Information Center

Marbury, Carl H.

This paper reviews the role of the black church in black American history and suggests ways in which its role must change to help blacks cope with our modern and technological society. Initially, religion was the one social institution which gave black slaves a common tie before the Civil War. Baptist and Methodist ideologies provided emotional…

Influence of Jet Fuel Composition on Aircraft Engine Emissions: A Synthesis of Aerosol Emissions Data from the NASA APEX, AAFEX, and ACCESS Missions

NASA Astrophysics Data System (ADS)

Moore, R.; Shook, M.; Beyersdorf, A. J.; Corr, C.; Herndon, S. C.; Knighton, W. B.; Miake-Lye, R. C.; Thornhill, K. L., II; Winstead, E.; Yu, Z.; Ziemba, L. D.; Anderson, B. E.

2015-12-01

We statistically analyze the impact of jet fuel properties on aerosols emitted by the NASA McDonnell Douglas DC-8 CFM56-2-C1 engines burning fifteen different aviation fuels. Data were collected for this single engine type during four different, comprehensive ground tests conducted over the past decade, which allow us to clearly link changes in aerosol emissions to fuel compositional changes. It is found that the volatile aerosol fraction dominates the number and volume emissions indices (EIs) over all engine powers, which are driven by changes in fuel aromatic and sulfur content. Meanwhile, the naphthalenic content of the fuel determines the magnitude of the non-volatile number and volume EI as well as the black carbon mass EI. Linear regression coefficients are reported for each aerosol EI in terms of these properties, engine fuel flow rate, and ambient temperature, and show that reducing both fuel sulfur content and napththalenes to near-zero levels would result in roughly a ten-fold decrease in aerosol number emitted per kg of fuel burn. This work informs future efforts to model aircraft emissions changes as the aviation fleet gradually begins to transition toward low-aromatic, low-sulfur alternative jet fuels from bio-based or Fischer-Tropsch production pathways.

Outflow-driven Transients from the Birth of Binary Black Holes. I. Tidally Locked Secondary Supernovae

NASA Astrophysics Data System (ADS)

Kimura, Shigeo S.; Murase, Kohta; Mészáros, Peter

2017-12-01

We propose a new type of electromagnetic transient associated with the birth of binary black holes (BBHs), which may lead to merger events accompanied by gravitational waves in ∼ 0.1{--}1 {Gyr}. We consider the newborn BBHs formed through the evolution of isolated massive stellar binaries. For a close massive binary, consisting of a primary black hole (BH) and a secondary Wolf–Rayet (WR) star that are orbiting around each other, the spin period of the WR star can be tidally synchronized to its orbital period. Then the angular momentum of the outer material of the WR star is large enough to form an accretion disk around a newborn, secondary BH, following its core-collapse. This disk may produce an energetic outflow with a kinetic energy of ∼ {10}50{--}{10}52 {erg} and an outflow velocity of ∼ {10}10 {cm} {{{s}}}-1, resulting in an optical transient with an absolute magnitude from approximately ‑14 to approximatley ‑17 with a duration of around a day. This type of transient also produces detectable radio signals ∼ 1{--}10 years after the birth of BBHs, via synchrotron emission from nonthermal electrons accelerated at external shocks. The predicted optical transients have a shorter duration than ordinary core-collapse supernovae. Dedicated optical transient surveys can detect them and distinguish them from ordinary SNe using the different features of its light curve and late-time spectrum. In this paper (Paper I), we investigate disk-driven outflows from the secondary BH, whereas possible signals from the primary BH will be discussed in Paper II.

Ecology-driven stereotypes override race stereotypes

PubMed Central

Williams, Keelah E. G.; Sng, Oliver; Neuberg, Steven L.

2016-01-01

Why do race stereotypes take the forms they do? Life history theory posits that features of the ecology shape individuals’ behavior. Harsh and unpredictable (“desperate”) ecologies induce fast strategy behaviors such as impulsivity, whereas resource-sufficient and predictable (“hopeful”) ecologies induce slow strategy behaviors such as future focus. We suggest that individuals possess a lay understanding of ecology’s influence on behavior, resulting in ecology-driven stereotypes. Importantly, because race is confounded with ecology in the United States, we propose that Americans’ stereotypes about racial groups actually reflect stereotypes about these groups’ presumed home ecologies. Study 1 demonstrates that individuals hold ecology stereotypes, stereotyping people from desperate ecologies as possessing faster life history strategies than people from hopeful ecologies. Studies 2–4 rule out alternative explanations for those findings. Study 5, which independently manipulates race and ecology information, demonstrates that when provided with information about a person’s race (but not ecology), individuals’ inferences about blacks track stereotypes of people from desperate ecologies, and individuals’ inferences about whites track stereotypes of people from hopeful ecologies. However, when provided with information about both the race and ecology of others, individuals’ inferences reflect the targets’ ecology rather than their race: black and white targets from desperate ecologies are stereotyped as equally fast life history strategists, whereas black and white targets from hopeful ecologies are stereotyped as equally slow life history strategists. These findings suggest that the content of several predominant race stereotypes may not reflect race, per se, but rather inferences about how one’s ecology influences behavior. PMID:26712013

Wind from the black-hole accretion disk driving a molecular outflow in an active galaxy.

PubMed

Tombesi, F; Meléndez, M; Veilleux, S; Reeves, J N; González-Alfonso, E; Reynolds, C S

2015-03-26

Powerful winds driven by active galactic nuclei are often thought to affect the evolution of both supermassive black holes and their host galaxies, quenching star formation and explaining the close relationship between black holes and galaxies. Recent observations of large-scale molecular outflows in ultraluminous infrared galaxies support this quasar-feedback idea, because they directly trace the gas from which stars form. Theoretical models suggest that these outflows originate as energy-conserving flows driven by fast accretion-disk winds. Proposed connections between large-scale molecular outflows and accretion-disk activity in ultraluminous galaxies were incomplete because no accretion-disk wind had been detected. Conversely, studies of powerful accretion-disk winds have until now focused only on X-ray observations of local Seyfert galaxies and a few higher-redshift quasars. Here we report observations of a powerful accretion-disk wind with a mildly relativistic velocity (a quarter that of light) in the X-ray spectrum of IRAS F11119+3257, a nearby (redshift 0.189) optically classified type 1 ultraluminous infrared galaxy hosting a powerful molecular outflow. The active galactic nucleus is responsible for about 80 per cent of the emission, with a quasar-like luminosity of 1.5 × 10(46) ergs per second. The energetics of these two types of wide-angle outflows is consistent with the energy-conserving mechanism that is the basis of the quasar feedback in active galactic nuclei that lack powerful radio jets (such jets are an alternative way to drive molecular outflows).

Black TiO2 nanobelts/g-C3N4 nanosheets Laminated Heterojunctions with Efficient Visible-Light-Driven Photocatalytic Performance

PubMed Central

Shen, Liyan; Xing, Zipeng; Zou, Jinlong; Li, Zhenzi; Wu, Xiaoyan; Zhang, Yuchi; Zhu, Qi; Yang, Shilin; Zhou, Wei

2017-01-01

Black TiO2 nanobelts/g-C3N4 nanosheets laminated heterojunctions (b-TiO2/g-C3N4) as visible-light-driven photocatalysts are fabricated through a simple hydrothermal-calcination process and an in-situ solid-state chemical reduction approach, followed by the mild thermal treatment (350 °C) in argon atmosphere. The prepared samples are evidently investigated by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption, and UV-visible diffuse reflectance spectroscopy, respectively. The results show that special laminated heterojunctions are formed between black TiO2 nanobelts and g-C3N4 nanosheets, which favor the separation of photogenerated electron-hole pairs. Furthermore, the presence of Ti3+ and g-C3N4 greatly enhance the absorption of visible light. The resultant b-TiO2/g-C3N4 materials exhibit higher photocatalytic activity than that of g-C3N4, TiO2, b-TiO2 and TiO2/g-C3N4 for degradation of methyl orange (95%) and hydrogen evolution (555.8 μmol h−1 g−1) under visible light irradiation. The apparent reaction rate constant (k) of b-TiO2/g-C3N4 is ~9 times higher than that of pristine TiO2. Therefore, the high-efficient laminated heterojunction composites will have potential applications in fields of environment and energy. PMID:28165021

Martin Robison Delany (1812-1885): physician, black separatist, explorer, soldier.

PubMed

Rosenfeld, L

1989-09-01

Martin Robison Delany's great contribution to American life and black history stems from his defiant blackness. He was America's first "Black Nationalist" and the intense embodiment of black pride. Ever changing in his career, he always identified with the black experience and its place in history. In an active life he was doctor, dentist, orator, editor, publisher, Harvard medical student, explorer, dabbler in Central American politics, army officer, and Reconstruction office seeker.

Quantifying the variability of potential black carbon transport from cropland burning in Russia driven by atmospheric blocking events.

NASA Astrophysics Data System (ADS)

Hall, J.; Loboda, T. V.

2017-12-01

Short lived aerosols and pollutants transported from northern mid-latitudes have amplified the short term warming in the Arctic region. Specifically, black carbon is recognized as the second most important human emission in regards to climate forcing, behind carbon dioxide with a total climate forcing of +1.1Wm-2. Studies have suggested that cropland burning may be a large contributor to the black carbon emissions which are directly deposited on the snow in the Arctic region. However, accurate monitoring of cropland burning from existing active fire and burned area products is limited, thereby leading to an underestimation in black carbon emissions from cropland burning. This research focuses on 1) assessing the potential for the deposition of hypothetical black carbon emissions from known cropland burning in Russia through low-level transport, and 2) identifying a possible atmospheric pattern that may enhance the transport of black carbon emissions to the Arctic. Specifically, atmospheric blocking events present a potential mechanism that could act to enhance the likelihood of transport or accelerate the transport of pollutants to the snow-covered Arctic from Russian cropland burning based on their persistent wind patterns. This research study confirmed the importance of Russian cropland burning as a potential source of black carbon deposition on the Arctic snow in the spring despite the low injection heights associated with cropland burning. Based on the successful transport pathways, this study identified the potential transport of black carbon from Russian cropland burning beyond 80°N which has important implications for permanent sea ice cover. Further, based on the persistent wind patterns of blocking events, this study identified that blocking events are able to accelerate potential transport and increase the success of transport of black carbon emissions to the snow-covered Arctic during spring when the impact on the snow/ice albedo is at its highest. The enhanced transport of black carbon has important implications for the efficacy of deposited black carbon. Therefore, understanding these relationships could lead to possible mitigation strategies for reducing the impact of deposition of black carbon from crop residue burning in the Arctic.

Black Nationalism and African-American Music

ERIC Educational Resources Information Center

Johnson, David

1977-01-01

Concludes that "A preoccupation with freedom seems to be a characteristic of black nationalists. Black musicians occupy positions in the music industry that are at best insecure. Consequently their political beliefs are never fully enunciated." Until society is radically changed, "the black nationalist musician will play a vital role in response…

Review Essay: Black Students in Higher Education: Why so Few?

ERIC Educational Resources Information Center

Keller, George

1989-01-01

A review of literature on declining Black student achievement attributes the problem to a hostile campus environment, competition with military service, reduced student aid, changes in Black males, poor preparation, choice of work over education, family deterioration, drug use, negative attitudes and behavior, and lack of Black leadership. (MSE)

Black Women and Homeownership: The Financial Challenge of the '80s.

ERIC Educational Resources Information Center

Better, Shirley

1979-01-01

States that changes in the economy, employment, family composition, and social attitudes now compel more Black women into howeownership. Reports that homeownership by Blacks prevents urban blight and gives Blacks more political power. Provides sources of information on mortgage credit and redress for discrimination. (Author/WP)

On Being an Angry Black Man

ERIC Educational Resources Information Center

Quaye, Stephen John

2017-01-01

Black men are often seen as problems, threats, and thugs. The mere existence of a Black body is often met with fear. Using autoethnographic mystory, I blend personal stories, poetry, song lyrics, and analysis to subvert the angry Black man mantra and explore the productive use of anger to stimulate change.

The Black Woman Cross-Culturally.

ERIC Educational Resources Information Center

Steady, Filomina Chioma, Ed.

This is a collection of anthropological and sociological articles on the black woman. Essays cover the experiences of black women in Africa, the Caribbean, South America, and the United States in politics, business, the community, the arts, the family, and social change. Several themes are present throughout this anthology, including black women's…

Dietary interventions for weight loss and cardiovascular risk reduction in people of African ancestry (blacks): a systematic review.

PubMed

Osei-Assibey, G; Boachie, C

2012-01-01

To systematically review weight and cardiovascular risk reduction in blacks by diet and lifestyle changes. Randomised and non-randomised controlled trials of diet with/without lifestyle changes with duration of intervention ≥3 months, and published between January 1990 and December 2009, were searched in electronic databases including MEDLINE, EMBASE, CINAHL and CCTR (Cochrane Controlled Trials Register). Studies were included if they reported weight/BMI changes with changes in at least one of the following: systolic and diastolic blood pressure, fasting plasma lipids and glucose, and glycated haemoglobin. Clinical, community and church-based interventions. Study participants were of African ancestry (blacks). Eighteen studies met the inclusion criteria. Average mean difference in weight loss was -2·66 kg, with improvements in all outcomes except total cholesterol. No significant difference was observed in outcome measures between all studies and studies that recruited only healthy participants or patients with type 2 diabetes. Diet and lifestyle changes result in weight loss with improvements in cardiovascular risk factors in blacks. However, more culturally tailored programmes have been suggested to motivate and encourage blacks to participate in intervention trials.

The Comparison of the Contents of Sugar, Amadori, and Heyns Compounds in Fresh and Black Garlic.

PubMed

Yuan, Heng; Sun, Linjuan; Chen, Min; Wang, Jun

2016-07-01

Black garlic is produced through thermal processing and is used as a healthy food throughout the world. Compared with fresh garlic, there are obvious changes in the color, taste, and biological functions of black garlic. To analyze and explain these changes, the contents of water-soluble sugars, fructan, and the key intermediate compounds (Heyns and Amadori) of the Maillard reaction in fresh raw garlic and black garlic were investigated, which were important to control and to evaluate the quality of black garlic. The results showed that the fructan contents in the black garlics were decreased by more than 84.6% compared with the fresh raw garlics, which translated into changes in the fructose and glucose contents. The water-soluble sugar content was drastically increased by values ranging from 187.79% to 790.96%. Therefore, the taste of the black garlic became very sweet. The sucrose content in black garlic was almost equivalent to fresh garlic. The Amadori and Heyns compounds were analyzed by HPLC-MS/MS in multiple reaction monitoring mode using the different characteristic fragment ions of Heyns and Amadori compounds. The total content of the 3 main Amadori and 3 Heyns compounds in black garlic ranged from 762.53 to 280.56 μg/g, which was 40 to 100-fold higher than the values in fresh raw garlic. This result was significant proof that the Maillard reaction in black garlic mainly utilized fructose and glucose, with some amino acids. © 2016 Institute of Food Technologists®

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

Change in Smoking, Diet, and Walking for Exercise in Blacks

ERIC Educational Resources Information Center

Berg, Carla J.; Thomas, Janet L.; An, Lawrence C.; Guo, Hongfei; Collins, Tracie; Okuyemi, Kolawole S.; Ahluwalia, Jasjit S.

2012-01-01

Positive changes in one health behavior may be accompanied by other constructive health behavior changes. Thus, the authors investigated the association of smoking reduction and cessation to changes in fruit and vegetable (FV) intake and engaging in walking for exercise. This study included 539 Black light smokers ([less than or equal to]10…

Contemporary genetic structure and postglacial demographic history of the black scorpionfish, Scorpaena porcus, in the Mediterranean and the Black Seas.

PubMed

Boissin, E; Micu, D; Janczyszyn-Le Goff, M; Neglia, V; Bat, L; Todorova, V; Panayotova, M; Kruschel, C; Macic, V; Milchakova, N; Keskin, Ç; Anastasopoulou, A; Nasto, I; Zane, L; Planes, S

2016-05-01

Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level. © 2016 John Wiley & Sons Ltd.

Measuring racial/ethnic disparities across the distribution of health care expenditures.

PubMed

Cook, Benjamin Lê; Manning, Willard G

2009-10-01

To assess whether black-white and Hispanic-white disparities increase or abate in the upper quantiles of total health care expenditure, conditional on covariates. Nationally representative adult population of non-Hispanic whites, African Americans, and Hispanics from the 2001-2005 Medical Expenditure Panel Surveys. We examine unadjusted racial/ethnic differences across the distribution of expenditures. We apply quantile regression to measure disparities at the median, 75th, 90th, and 95th quantiles, testing for differences over the distribution of health care expenditures and across income and education categories. We test the sensitivity of the results to comparisons based only on health status and estimate a two-part model to ensure that results are not driven by an extremely skewed distribution of expenditures with a large zero mass. Black-white and Hispanic-white disparities diminish in the upper quantiles of expenditure, but expenditures for blacks and Hispanics remain significantly lower than for whites throughout the distribution. For most education and income categories, disparities exist at the median and decline, but remain significant even with increased education and income. Blacks and Hispanics receive significantly disparate care at high expenditure levels, suggesting prioritization of improved access to quality care among minorities with critical health issues.

'Black universe' epoch in string cosmology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchel, Alex; Perimeter Institute for Theoretical Physics, Waterloo, Ontario, N2J 2W9; Kofman, Lev

2008-10-15

String theory compactification involves manifolds with multiple warp factors. For cosmological applications, we often introduce a short, high-energy inflationary throat, and a long, low-energy standard model (SM) throat. It is assumed that at the end of inflation, the excited Kaluza-Klein modes from the inflationary throat tunnel to the SM throat and reheat standard model degrees of freedom, which are attached to probe brane(s). However, the huge hierarchy of energy scales can result in a highly dynamic transition of the throat geometry. We point out that in such a cosmological scenario the standard model throat (together with SM brane) will bemore » cloaked by a Schwarzschild horizon, produced by the Kaluza-Klein modes tunneling from the short throat. The black brane formation is dual to the first order chiral phase transition of the cascading gauge theory. We calculate the critical energy density corresponding the formation of the black hole (BH) horizon in the long throat. We discuss the duality between 'black universe' cosmology and an expanding universe driven by the hot gauge theory radiation. We address the new problem of the hierarchical multiple-throat scenarios: SM brane disappearance after the decay of the BH horizon.« less

Protomagnetar and black hole formation in high-mass stars

NASA Astrophysics Data System (ADS)

Obergaulinger, M.; Aloy, M. Á.

2017-07-01

Using axisymmetric simulations coupling special relativistic magnetohydrodynamics (MHD), an approximate post-Newtonian gravitational potential and two-moment neutrino transport, we show different paths for the formation of either protomagnetars or stellar mass black holes. The fraction of prototypical stellar cores which should result in collapsars depends on a combination of several factors, among which the structure of the progenitor star and the profile of specific angular momentum are probably the foremost. Along with the implosion of the stellar core, we also obtain supernova-like explosions driven by neutrino heating and hydrodynamic instabilities or by magneto-rotational effects in cores of high-mass stars. In the latter case, highly collimated, mildly relativistic outflows are generated. We find that after a rather long post-collapse phase (lasting ≳1 s) black holes may form in cases both of successful and failed supernova-like explosions. A basic trend is that cores with a specific angular momentum smaller than that obtained by standard, one-dimensional stellar evolution calculations form black holes (and eventually collapsars). Complementary, protomagnetars result from stellar cores with the standard distribution of specific angular momentum obtained from prototypical stellar evolution calculations including magnetic torques and moderate to large mass-loss rates.

Discordant timing between antennae disrupts sun compass orientation in migratory monarch butterflies

PubMed Central

Guerra, Patrick A; Merlin, Christine; Gegear, Robert J; Reppert, Steven M

2014-01-01

To navigate during their long-distance migration, monarch butterflies (Danaus plexippus) use a time-compensated sun compass. The sun compass timing elements reside in light-entrained circadian clocks in the antennae. Here we show that either antenna is sufficient for proper time compensation. However, migrants with either antenna painted black (to block light entrainment) and the other painted clear (to permit light entrainment) display disoriented group flight. Remarkably, when the black-painted antenna is removed, re-flown migrants with a single, clear-painted antenna exhibit proper orientation behaviour. Molecular correlates of clock function reveal that period and timeless expression is highly rhythmic in brains and clear-painted antennae, while rhythmic clock gene expression is disrupted in black-painted antennae. Our work shows that clock outputs from each antenna are processed and integrated together in the monarch time-compensated sun compass circuit. This dual timing system is a novel example of the regulation of a brain-driven behaviour by paired organs. PMID:22805565

Changes in Financial Aid and Student Enrollment at Historically Black Colleges and Universities after the Tightening of PLUS Credit Standards: An Update for the 2013/14 School Year. REL 2017-254

ERIC Educational Resources Information Center

Johnson, Matthew; Bruch, Julie; Gill, Brian

2017-01-01

In 2011 the U.S. Department of Education tightened the credit standards for Parent Loans for Undergraduate Students (PLUS). Concerned about the possible effects of this change on historically Black colleges and universities (HBCUs), Regional Educational Laboratory Mid-Atlantic's Historically Black Colleges and Universities College Completion…

A church-based intervention to change attitudes about physical activity among Black adolescent girls: a feasibility study.

PubMed

Thompson, Wanda M; Berry, Diane; Hu, Jie

2013-05-01

To feasibility test a 12-week church-based physical activity intervention that was culturally sensitive, age- and gender specific directed at changing attitudes of Black adolescent girls' to be more physically active. A one-group pre- and posttest design was used. A convenience sample of Black adolescent girls between the age of 12-18 (n = 41). A 60-min 12-week church-based program that included interactive educational sessions followed by a high energy dance aerobics class was used. Data were collected on biophysical measures. Surveys were used to assess the following variables: attitudes, enjoyment, self-efficacy, intention, social and family support, and PA levels. Paired t-tests and repeated measures ANOVA revealed no significant changes in key variables. Positive changes were noted in the odds ratios for attitudes, self-efficacy, and intention. Body mass index, metabolic equivalent tasks, and fitness showed positive trends from pre to post intervention. Family support was significantly correlated with physical activity level (p < .01). The study showed that physical activity programs in Black churches aimed at Black adolescent girls are feasible. Participants evaluated the intervention very favorably. Family support may be a key factor in increasing physical activity levels in Black adolescent girls. © 2012 Wiley Periodicals, Inc.

Black Hole Coalescence: The Gravitational Wave Driven Phase

NASA Technical Reports Server (NTRS)

Schnittman, Jeremy D.

2011-01-01

When two supermassive black holes (SMBHS) approach within 1-10 mpc, gravitational wave (GW) losses begin to dominate the evolution of the binary, pushing the system to merge in a relatively small time. During this final inspiral regime, the system will emit copious energy in GWs, which should be directly detectable by pulsar timing arrays and space-based interferometers. At the same time, any gas or stars in the immediate vicinity of the merging 5MBHs can get heated and produce bright electromagnetic (EM) counterparts to the GW signals. We present here a number of possible mechanisms by which simultaneous EM and GW signals will yield valuable new information about galaxy evolution, accretion disk dynamics, and fundamental physics in the most extreme gravitational fields.

What's technology cooking up? A systematic review of the use of technology in adolescent food literacy programs.

PubMed

Wickham, Catherine A; Carbone, Elena T

2018-06-01

Over one-third of adolescents are overweight or obese. Food literacy (FL), the ability to plan and manage, select, prepare, and eat healthy foods, is a contemporary concept that provides a mechanism to understand the relationship between food-related knowledge and skills and dietary intake. Innovative interventions which focus on the core concepts of FL and include generationally appropriate technology have the potential to provide positive impact on the dietary habits of adolescents. This systematic review followed PRISMA guidelines and employed the Downs and Black criteria for rating studies. Titles and abstracts of 545 articles were collected and reviewed from 13 electronic databases. Studies were selected if they were peer-reviewed, included adolescents 12-19 years-old, incorporated concepts related to FL, and employed technology as part of the intervention. Eight studies, six randomized controlled trials (RCT) and two interventions without controls were included. Seven of the interventions used Internet or web-based platforms to access program components and all RCTs incorporated game elements. Studies included between two and four constructs of FL. All reported positive changes in food intake with five reporting significant positive pre- and post-intervention changes. Few technology-driven FL-related studies exist within the literature. Although all studies reported improvements in dietary intake, due to variation in program design, delivery, and evaluation it is difficult to tease out the effect of the technology component. Continued research is needed to: 1) determine the degree to which FL should be included in interventions to effect a positive change on dietary intake; 2) develop adolescent-specific FL measures to more appropriately evaluate changes in knowledge, food-related skills, and dietary intake; and 3) design technology-driven interventions so that technology components can be analyzed separately from other program elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Climate responses to anthropogenic emissions of short-lived climate pollutants

NASA Astrophysics Data System (ADS)

Baker, L. H.; Collins, W. J.; Olivié, D. J. L.; Cherian, R.; Hodnebrog, Ø.; Myhre, G.; Quaas, J.

2015-07-01

Policies to control air quality focus on mitigating emissions of aerosols and their precursors, and other short-lived climate pollutants (SLCPs). On a local scale, these policies will have beneficial impacts on health and crop yields, by reducing particulate matter (PM) and surface ozone concentrations; however, the climate impacts of reducing emissions of SLCPs are less straightforward to predict. In this paper we consider a set of idealized, extreme mitigation strategies, in which the total anthropogenic emissions of individual SLCP emissions species are removed. This provides an upper bound on the potential climate impacts of such air quality strategies. We focus on evaluating the climate responses to changes in anthropogenic emissions of aerosol precursor species: black carbon (BC), organic carbon (OC) and sulphur dioxide (SO2). We perform climate integrations with four fully coupled atmosphere-ocean global climate models (AOGCMs), and examine the effects on global and regional climate of removing the total land-based anthropogenic emissions of each of the three aerosol precursor species. We find that the SO2 emissions reductions lead to the strongest response, with all models showing an increase in surface temperature focussed in the Northern Hemisphere mid and (especially) high latitudes, and showing a corresponding increase in global mean precipitation. Changes in precipitation patterns are driven mostly by a northward shift in the ITCZ (Intertropical Convergence Zone), consistent with the hemispherically asymmetric warming pattern driven by the emissions changes. The BC and OC emissions reductions give a much weaker response, and there is some disagreement between models in the sign of the climate responses to these perturbations. These differences between models are due largely to natural variability in sea-ice extent, circulation patterns and cloud changes. This large natural variability component to the signal when the ocean circulation and sea-ice are free-running means that the BC and OC mitigation measures do not necessarily lead to a discernible climate response.

Climate responses to anthropogenic emissions of short-lived climate pollutants

NASA Astrophysics Data System (ADS)

Baker, L. H.; Collins, W. J.; Olivié, D. J. L.; Cherian, R.; Hodnebrog, Ø.; Myhre, G.; Quaas, J.; Samset, B. H.

2015-02-01

Policies to control air quality focus on mitigating emissions of aerosols and their precursors, and other short-lived climate pollutants (SLCPs). On a local scale, these policies will have beneficial impacts on health and crop yields, by reducing particulate matter (PM) and surface ozone concentrations; however, the climate impacts of reducing emissions of SLCPs are less straightforward to predict. In this paper we consider a set of idealised, extreme mitigation strategies, in which the total anthropogenic emissions of individual SLCP emissions species are removed. This provides an upper bound on the potential climate impacts of such air quality strategies. We focus on evaluating the climate responses to changes in anthropogenic emissions of aerosol precursor species: black carbon (BC), organic carbon (OC) and sulphur dioxide (SO2). We perform climate integrations with four fully coupled atmosphere-ocean global climate models (AOGCMs), and examine the effects on global and regional climate of removing the total land-based anthropogenic emissions of each of the three aerosol precursor species. We find that the SO2 emissions reductions lead to the strongest response, with all three models showing an increase in surface temperature focussed in the northern hemisphere high latitudes, and a corresponding increase in global mean precipitation and run-off. Changes in precipitation and run-off patterns are driven mostly by a northward shift in the ITCZ, consistent with the hemispherically asymmetric warming pattern driven by the emissions changes. The BC and OC emissions reductions give a much weaker forcing signal, and there is some disagreement between models in the sign of the climate responses to these perturbations. These differences between models are due largely to natural variability in sea-ice extent, circulation patterns and cloud changes. This large natural variability component to the signal when the ocean circulation and sea-ice are free-running means that the BC and OC mitigation measures do not necessarily lead to a discernible climate response.

The Western Film: Holywood Myths and One Black Reality.

ERIC Educational Resources Information Center

Gill, Waliyy

1986-01-01

Discusses the portrayal of Blacks in American Western films since the first Western was made in 1903. Also describes the changing social and historical context of the film industry as related to Blacks. (GC)

Relaxation near Supermassive Black Holes Driven by Nuclear Spiral Arms: Anisotropic Hypervelocity Stars, S-stars, and Tidal Disruption Events

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamers, Adrian S.; Perets, Hagai B., E-mail: hamers@ias.edu

Nuclear spiral arms are small-scale transient spiral structures found in the centers of galaxies. Similarly to their galactic-scale counterparts, nuclear spiral arms can perturb the orbits of stars. In the case of the Galactic center (GC), these perturbations can affect the orbits of stars and binaries in a region extending to several hundred parsecs around the supermassive black hole (SMBH), causing diffusion in orbital energy and angular momentum. This diffusion process can drive stars and binaries to close approaches with the SMBH, disrupting single stars in tidal disruption events (TDEs), or disrupting binaries, leaving a star tightly bound to themore » SMBH and an unbound star escaping the galaxy, i.e., a hypervelocity star (HVS). Here, we consider diffusion by nuclear spiral arms in galactic nuclei, specifically the Milky Way GC. We determine nuclear-spiral-arm-driven diffusion rates using test-particle integrations and compute disruption rates. Our TDE rates are up to 20% higher compared to relaxation by single stars. For binaries, the enhancement is up to a factor of ∼100, and our rates are comparable to the observed numbers of HVSs and S-stars. Our scenario is complementary to relaxation driven by massive perturbers. In addition, our rates depend on the inclination of the binary with respect to the Galactic plane. Therefore, our scenario provides a novel potential source for the observed anisotropic distribution of HVSs. Nuclear spiral arms may also be important for accelerating the coalescence of binary SMBHs and for supplying nuclear star clusters with stars and gas.« less

The Concept of Black Music: A Survey Analysis.

ERIC Educational Resources Information Center

Handy, D. Antoinette

1978-01-01

The author's research suggests that: (1) the label "Black music" needs clarification; (2) many proponents of the slogan hold traditional White attitudes; (3) the attitudes of Black musicians themselves need to be changed; (4) Black music needs to be included in the political struggle; and (5) the music industry is discriminatory. (Author/MC)

Empowering Rhetoric: Black Students Writing Black Panthers.

ERIC Educational Resources Information Center

Pough, Gwendolyn D.

2002-01-01

Examines Black student responses to Black Panther Party documents and how those documents moved the students toward change. Maintains that by allowing the classroom to function as a public space which students can discuss the issues that matter to them, teachers can help to foster and encourage student activism and ultimately their empowerment.…

Racial Identity and Depressive Symptoms among Black Emerging Adults: The Moderating Effects of Neighborhood Racial Composition

PubMed Central

Hurd, Noelle M; Sellers, Robert M.; Cogburn, Courtney D.; Butler-Barnes, Sheretta T.; Zimmerman, Marc A

2012-01-01

In the current study, we explored patterns of change in Black emerging adults’ racial identity beliefs during the transition to adulthood, assessed neighborhood racial composition effects on Black emerging adults’ racial identity beliefs, and tested the moderating effects of neighborhood racial composition on the relationship between Black emerging adults’ racial identity beliefs and depressive symptoms over time. Participants in the current study included 570 Black adolescents (52% female) who were transitioning into adulthood (senior year of high school through 5 years post-high school). We did not find average patterns of change in Black emerging adults’ racial identity beliefs over time. Further, neighborhood racial composition did not predict participants’ beginning status or growth in racial identity beliefs over time. We, however, found evidence that neighborhood racial composition may moderate the association between Black emerging adults’ racial identity beliefs and symptoms of depression over time. Findings from the current study underscore the importance of considering how the larger social context may interact with individuals’ racial identity beliefs to influence Black emerging adults’ psychological health. PMID:22709129

Racial identity and depressive symptoms among Black emerging adults: the moderating effects of neighborhood racial composition.

PubMed

Hurd, Noelle M; Sellers, Robert M; Cogburn, Courtney D; Butler-Barnes, Sheretta T; Zimmerman, Marc A

2013-05-01

In the current study, we explored patterns of change in Black emerging adults' racial identity beliefs during the transition to adulthood, assessed neighborhood racial composition effects on Black emerging adults' racial identity beliefs, and tested the moderating effects of neighborhood racial composition on the associations between Black emerging adults' racial identity beliefs and depressive symptoms over time. Participants in the current study included 570 Black adolescents (52% female) who were transitioning into adulthood (senior year of high school through 5 years post- high school). We did not find average patterns of change in Black emerging adults' racial identity beliefs over time. Further, neighborhood racial composition did not predict participants' beginning status or growth in racial identity beliefs over time. We, however, found evidence that neighborhood racial composition may moderate the associations between Black emerging adults' racial identity beliefs and symptoms of depression over time. Findings from the current study underscore the importance of considering how the larger social context may interact with individuals' racial identity beliefs to influence Black emerging adults' psychological health.

Resting energy expenditure changes with weight loss: racial differences.

PubMed

Wang, Xuewen; You, Tongjian; Lenchik, Leon; Nicklas, Barbara J

2010-01-01

It is controversial whether weight loss reduces resting energy expenditure (REE) to a different magnitude in black and white women. This aim of this study was to determine whether changes in REE with weight loss were different between black and white postmenopausal women, and whether changes in body composition (including regional lean and fat mass) were associated with REE changes within each race. Black (n = 26) and white (n = 65) women (age = 58.2 +/- 5.4 years, 25 < BMI < 40 kg/m(2)) completed a 20-week weight-loss intervention. Body weight, lean and fat mass (total body, limb, and trunk) via dual-energy X-ray absorptiometry, and REE via indirect calorimetry were measured before and after the intervention. We found that baseline REE positively correlated with body weight, lean and fat mass (total, limb, and trunk) in white women only (P < 0.05 for all). The intervention decreased absolute REE in both races similarly (1,279 +/- 162 to 1,204 +/- 169 kcal/day in blacks; 1,315 +/- 200 to 1,209 +/- 185 kcal/day in whites). REE remained decreased after adjusting for changes in total or limb lean mass in black (1,302-1,182 kcal/day, P = 0.043; 1,298-1,144 kcal/day, P = 0.006, respectively), but not in white, women. Changes in REE correlated with changes in body weight (partial r = 0.277) and fat mass (partial r = 0.295, 0.275, and 0.254 for total, limb, and trunk, respectively; P < 0.05) independent of baseline REE in white women. Therefore, with weight loss, REE decreased in proportion to the amount of fat and lean mass lost in white, but not black, women.

Improving the clinical correlation of multiple sclerosis black hole volume change by paired-scan analysis.

PubMed

Tam, Roger C; Traboulsee, Anthony; Riddehough, Andrew; Li, David K B

2012-01-01

The change in T 1-hypointense lesion ("black hole") volume is an important marker of pathological progression in multiple sclerosis (MS). Black hole boundaries often have low contrast and are difficult to determine accurately and most (semi-)automated segmentation methods first compute the T 2-hyperintense lesions, which are a superset of the black holes and are typically more distinct, to form a search space for the T 1w lesions. Two main potential sources of measurement noise in longitudinal black hole volume computation are partial volume and variability in the T 2w lesion segmentation. A paired analysis approach is proposed herein that uses registration to equalize partial volume and lesion mask processing to combine T 2w lesion segmentations across time. The scans of 247 MS patients are used to compare a selected black hole computation method with an enhanced version incorporating paired analysis, using rank correlation to a clinical variable (MS functional composite) as the primary outcome measure. The comparison is done at nine different levels of intensity as a previous study suggests that darker black holes may yield stronger correlations. The results demonstrate that paired analysis can strongly improve longitudinal correlation (from -0.148 to -0.303 in this sample) and may produce segmentations that are more sensitive to clinically relevant changes.

Rethinking Black Hole Accretion Discs

NASA Astrophysics Data System (ADS)

Salvesen, Greg

Accretion discs are staples of astrophysics. Tapping into the gravitational potential energy of the accreting material, these discs are highly efficient machines that produce copious radiation and extreme outflows. While interesting in their own right, accretion discs also act as tools to study black holes and directly influence the properties of the Universe. Black hole X-ray binaries are fantastic natural laboratories for studying accretion disc physics and black hole phenomena. Among many of the curious behaviors exhibited by these systems are black hole state transitions -- complicated cycles of dramatic brightening and dimming. Using X-ray observations with high temporal cadence, we show that the evolution of the accretion disc spectrum during black hole state transitions can be described by a variable disc atmospheric structure without invoking a radially truncated disc geometry. The accretion disc spectrum can be a powerful diagnostic for measuring black hole spin if the effects of the disc atmosphere on the emergent spectrum are well-understood; however, properties of the disc atmosphere are largely unconstrained. Using statistical methods, we decompose this black hole spin measurement technique and show that modest uncertainties regarding the disc atmosphere can lead to erroneous spin measurements. The vertical structure of the disc is difficult to constrain due to our ignorance of the contribution to hydrostatic balance by magnetic fields, which are fundamental to the accretion process. Observations of black hole X-ray binaries and the accretion environments near supermassive black holes provide mounting evidence for strong magnetization. Performing numerical simulations of accretion discs in the shearing box approximation, we impose a net vertical magnetic flux that allows us to effectively control the level of disc magnetization. We study how dynamo activity and the properties of turbulence driven by the magnetorotational instability depend on the magnetized state of the gas, spanning weak-to-strong disc magnetization regimes. We also demonstrate that a background poloidal magnetic flux is required to form and sustain a strongly magnetized accretion disc. This thesis motivates the need for understanding how magnetic fields affect the observed spectrum from black hole accretion discs.

Unpacking the racial disparity in HIV rates: the effect of race on risky sexual behavior among Black young men who have sex with men (YMSM).

PubMed

Clerkin, Elise M; Newcomb, Michael E; Mustanski, Brian

2011-08-01

The purpose of this study is to evaluate the large disparity in HIV prevalence rates between young Black and White Americans, including young men who have sex with men (YMSM). Research focusing on individual behaviors has proven insufficient to explain the disproportionately high rate of HIV among Black YMSM. The purpose of the present study was to gain a greater understanding of the pronounced racial disparity in HIV by evaluating whether YMSM are more likely to engage in risky sexual behaviors as a function of their partner's race. Participants included 117 YMSM from a longitudinal study evaluating lesbian, gay, bisexual, and transgender youth (ages 16-20 at baseline), who reported characteristics and risk behaviors of up to 9 sexual partners over an 18-month period. Results indicated that participants were less likely to have unprotected sex with Black partners, and this finding was not driven by a response bias (i.e., Black YMSM did not appear to be minimizing their reports of unprotected sex). Furthermore, there was support for the hypothesis that participants' sexual networks were partially determined by their race insofar as sexual partnerships were much more likely to be intra-racial (as opposed to interracial). It is possible that dyad- and sexual network-level factors may be needed to understand racial disparities in HIV among YMSM.

Soil fauna community in the black soil of northeast China under different conservation tillage systems

USDA-ARS?s Scientific Manuscript database

Soil fauna is an important component in soil ecosystem. Through the soil moisture changes, soil environment is changed under different tillage systems, and then the population of soil fauna also is changed. This study tested whether conservation tillage or conventional tillage (CT) of black soil fie...

Separation anxiety: Stress, tension and cytokinesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohan, Krithika; Iglesias, Pablo A., E-mail: pi@jhu.edu; Robinson, Douglas N., E-mail: dnr@jhmi.edu

Cytokinesis, the physical separation of a mother cell into two daughter cells, progresses through a series of well-defined changes in morphology. These changes involve distinct biochemical and mechanical processes. Here, we review the mechanical features of cells during cytokinesis, discussing both the material properties as well as sources of stresses, both active and passive, which lead to the observed changes in morphology. We also describe a mechanosensory feedback control system that regulates protein localization and shape progression during cytokinesis. -- Highlights: Black-Right-Pointing-Pointer Cytokinesis progresses through three distinct mechanical phases. Black-Right-Pointing-Pointer Cortical tension initially resists deformation of mother cell. Black-Right-Pointing-Pointer Latemore » in cytokinesis, cortical tension provides stress, enabling furrow ingression. Black-Right-Pointing-Pointer A mechanosensory feedback control system regulates cytokinesis.« less

Feedbacks between Climate and Fire Emissions

DTIC Science & Technology

2011-11-29

CH4 2. Direct emission of short-lived climate forcers - Black Carbon - Particulate organic matter 3. Production of tropospheric ozone and secondary... tropospheric ozone and secondary organic particulate matter 4. Changes in land surface properties - Black carbon on snow - Albedo Radiative Forcing of Black...lived  climate forcers:  particles 3.  Ozone   production 4. Change in  surface properties Fires Impacts on the Climate System 1. Emission of long lived

Racial disparities in diabetes mortality in the 50 most populous US cities.

PubMed

Rosenstock, Summer; Whitman, Steve; West, Joseph F; Balkin, Michael

2014-10-01

While studies have consistently shown that in the USA, non-Hispanic Blacks (Blacks) have higher diabetes prevalence, complication and death rates than non-Hispanic Whites (Whites), there are no studies that compare disparities in diabetes mortality across the largest US cities. This study presents and compares Black/White age-adjusted diabetes mortality rate ratios (RRs), calculated using national death files and census data, for the 50 most populous US cities. Relationships between city-level diabetes mortality RRs and 12 ecological variables were explored using bivariate correlation analyses. Multivariate analyses were conducted using negative binomial regression to examine how much of the disparity could be explained by these variables. Blacks had statistically significantly higher mortality rates compared to Whites in 39 of the 41 cities included in analyses, with statistically significant rate ratios ranging from 1.57 (95 % CI: 1.33-1.86) in Baltimore to 3.78 (95 % CI: 2.84-5.02) in Washington, DC. Analyses showed that economic inequality was strongly correlated with the diabetes mortality disparity, driven by differences in White poverty levels. This was followed by segregation. Multivariate analyses showed that adjusting for Black/White poverty alone explained 58.5 % of the disparity. Adjusting for Black/White poverty and segregation explained 72.6 % of the disparity. This study emphasizes the role that inequalities in social and economic determinants, rather than for example poverty on its own, play in Black/White diabetes mortality disparities. It also highlights how the magnitude of the disparity and the factors that influence it can vary greatly across cities, underscoring the importance of using local data to identify context specific barriers and develop effective interventions to eliminate health disparities.

Spacetime topology change and black hole information

NASA Astrophysics Data System (ADS)

Hsu, Stephen D. H.

2007-01-01

Topology change-the creation of a disconnected baby universe-due to black hole collapse may resolve the information loss paradox. Evolution from an early time Cauchy surface to a final surface which includes a slice of the disconnected region can be unitary and consistent with conventional quantum mechanics. We discuss the issue of cluster decomposition, showing that any violations thereof are likely to be unobservably small. Topology change is similar to the black hole remnant scenario and only requires assumptions about the behavior of quantum gravity in Planckian regimes. It does not require non-locality or any modification of low-energy physics.

Labor Market Dropouts and Trends in the Wages of Black and White Men.

ERIC Educational Resources Information Center

Juhn, Chinhui

2003-01-01

When discouraged unemployed black males are accounted for, real wage growth for black men over 1969-98 is reduced by about 40% and black-white wage convergence by about one-third. An important source of selection bias is the changing gap between wages of workers and potential wages of nonworkers. (Contains 20 references.) (SK)

Living Research: Oral History in the Black Community.

ERIC Educational Resources Information Center

Adesiyan, H. Rose

Both blacks and whites arriving in Hammond, Indiana in the late 1800s and early 1900s played significant roles in its development. The role of the early black settlers has been largely untold outside the black community and is thus unappreciated. The goal of this project was to change this historical neglect. Statistical data from traditional…

The Black Urban Population of the Pre-civil War South

ERIC Educational Resources Information Center

Wilkie, Jane Riblett

1976-01-01

Examines the urbanization of blacks in the slave states from 1790 to 1860. Changes in the geographic distribution and demographic structure of the black urban population provide new evidence to evaluate the causes of the decline of urban blacks and reveal the likelihood of a disproportionate incidence of incomplete families for both slave and free…

Historical, Institutional, and Contextual Determinants of Black Enrollment in Predominantly White Colleges and Universities, 1946 to 1974.

ERIC Educational Resources Information Center

Arce, Carlos H.

In this dissertation, black enrollment in predominantly white colleges is examined by identifying forces that have caused its fluctuation and distribution. The strength of these determinants is assessed and an explanatory model of black enrollment change is suggested. A critical procedure is compiling black enrollment statistics: national…

Exploring the Perceptions of HBCU Student Affairs Practitioners toward the Racial Diversification of Black Colleges

ERIC Educational Resources Information Center

Palmer, Robert T.; Arroyo, Andrew T.; Maramba, Dina C.

2018-01-01

While research has shown that the racial diversity of historically Black colleges and universities (HBCUs) is increasing, literature suggests that some stakeholders at HBCUs feel the diversification of Black colleges could change their culture, which some see as vital for promoting the success of Black students. Given this, the following study…

Webinar Presentation: Particle-Resolved Simulations for Quantifying Black Carbon Climate Impact and Model Uncertainty

EPA Pesticide Factsheets

This presentation, Particle-Resolved Simulations for Quantifying Black Carbon Climate Impact and Model Uncertainty, was given at the STAR Black Carbon 2016 Webinar Series: Changing Chemistry over Time held on Oct. 31, 2016.

Labor Market Changes for Black Men Since 1964

ERIC Educational Resources Information Center

Vroman, Wayne

1975-01-01

Three determinants of black male relative earnings are examined: relative educational position, industrial distribution of employment, and labor market discrimination. Overall improvement in the relative position of black men has been noted, but large racial disparities persist. (MW)

The Relativistic Iron Line Profile in the Seyfert 1 Galaxy IC4329a

NASA Technical Reports Server (NTRS)

Done, C.; Madejski, G. M.; Zycki, P. T.

2000-01-01

We present simultaneous ASCA and RXTE data on the bright Seyfert 1 galaxy IC4329a. The iron line is significantly broadened, but not to the extent expected from an accretion disk which extends down to the last stable orbit around a black hole. We marginally detect a narrow line component, presumably from the molecular torus, but, even including this gives a line profile from the accretion disk which is significantly narrower that that seen in MCG-6-30-15, and is much more like that seen from the low/hard state galactic black hole candidates. This is consistent with the inner disk being truncated before the last stable orbit, forming a hot flow at small radii as in the ADAF models. However. we cannot rule out the presence of an inner disk which does not contribute to the reflected spectrum. either because of extreme ionisation suppressing the characteristic atomic features of the reflected spectrum or because the X-ray source is intrinsically anisotropic, so it does not illuminate the inner disk. The source was monitored by RXTE every 2 days for 2 months, and these snapshot spectra show that there is intrinsic spectral variability. The data are good enough to disentangle the power law from the reflected continuum and we see that the power law softens as the source brightens. The lack of a corresponding increase in the observed reflected spectrum implies that either the changes in disk inner radial extent/ionization structure are small, or that the variability is actually driven by changes in the seed photons which are decoupled from the hard X-ray mechanism.

Substance Use and Sexual Risk Behavior Among Black South African Men Who Have Sex With Men: The Moderating Effects of Reasons for Drinking and Safer Sex Intentions.

PubMed

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

2017-07-01

Research studies suggest an association between substance use and sexual risk behavior, but are not completely consistent. The moderating effects of other psychosocial factors might help explain these inconsistencies. The current study therefore assessed whether substance use is associated with sexual risk behavior, and whether this relationship is modified by expectancies about the effects of alcohol, reasons for consuming alcohol, or intentions to engage in safe sex. A cross-sectional survey was conducted among 480 black South African men who have sex with men recruited using respondent-driven sampling. In multivariable analyses, the effect of alcohol use on unprotected receptive anal intercourse (URAI) was modified by drinking to enhance social interaction (R 2 change = 0.03, p < 0.01). The effect of drug use on URAI was modified by safe sex intentions (R 2 change = 0.03, p < 0.001). Alcohol use was positively associated with URAI only among those who drink to enhance social interaction (β = 0.08, p < 0.05). Drug use was positively associated with URAI only among those with high safe sex intentions (β = 0.30, p < 0.001). Our findings suggest that efforts to minimize the impact of substance use on HIV risk behavior should target men who drink to enhance social interaction and men who intend to engage in safer sex. Efforts made to increase safer sex intentions as a way to reduce HIV risk behavior should additionally consider the effects of substance use.

Control of fossil-fuel particulate black carbon and organic matter, possibly the most effective method of slowing global warming

NASA Astrophysics Data System (ADS)

Jacobson, Mark Z.

2002-10-01

Under the 1997 Kyoto Protocol, no control of black carbon (BC) was considered. Here, it is found, through simulations in which 12 identifiable effects of aerosol particles on climate are treated, that any emission reduction of fossil-fuel (f.f.) particulate BC plus associated organic matter (OM) may slow global warming more than may any emission reduction of CO2 or CH4 for a specific period. When all f.f. BC + OM and anthropogenic CO2 and CH4 emissions are eliminated together, the period is 25-100 years. It is also estimated that historical net global warming can be attributed roughly to greenhouse gas plus f.f. BC + OM warming minus substantial cooling by other particles. Eliminating all f.f. BC + OM could eliminate 20-45% of net warming (8-18% of total warming before cooling is subtracted out) within 3-5 years if no other change occurred. Reducing CO2 emissions by a third would have the same effect, but after 50-200 years. Finally, diesel cars emitting continuously under the most recent U.S. and E.U. particulate standards (0.08 g/mi; 0.05 g/km) may warm climate per distance driven over the next 100+ years more than equivalent gasoline cars. Thus, fuel and carbon tax laws that favor diesel appear to promote global warming. Toughening vehicle particulate emission standards by a factor of 8 (0.01 g/mi; 0.006 g/km) does not change this conclusion, although it shortens the period over which diesel cars warm to 13-54 years. Although control of BC + OM can slow warming, control of greenhouse gases is necessary to stop warming. Reducing BC + OM will not only slow global warming but also improve human health.

Heat-induced chemical and color changes of extractive-free Black Locust (Rosinia Pseudoacacia) wood

Treesearch

Yao Chen; Jianmin Gao; Yongming Fan; Mandla A. Tshabalala; Nicole M. Stark

2012-01-01

To investigate chemical and color changes of the polymeric constituents of black locust (Robinia pseudoacacia) wood during heat treatment, extractive-free wood flour was conditioned to 30% initial moisture content (MC) and heated for 24 h at 120 °C in either an oxygen or nitrogen atmosphere. The color change was measured using the CIELAB color system. Chemical changes...

Accretion onto some well-known regular black holes

NASA Astrophysics Data System (ADS)

Jawad, Abdul; Shahzad, M. Umair

2016-03-01

In this work, we discuss the accretion onto static spherically symmetric regular black holes for specific choices of the equation of state parameter. The underlying regular black holes are charged regular black holes using the Fermi-Dirac distribution, logistic distribution, nonlinear electrodynamics, respectively, and Kehagias-Sftesos asymptotically flat regular black holes. We obtain the critical radius, critical speed, and squared sound speed during the accretion process near the regular black holes. We also study the behavior of radial velocity, energy density, and the rate of change of the mass for each of the regular black holes.

Association between expansion of primary healthcare and racial inequalities in mortality amenable to primary care in Brazil: A national longitudinal analysis.

PubMed

Hone, Thomas; Rasella, Davide; Barreto, Mauricio L; Majeed, Azeem; Millett, Christopher

2017-05-01

Universal health coverage (UHC) can play an important role in achieving Sustainable Development Goal (SDG) 10, which addresses reducing inequalities, but little supporting evidence is available from low- and middle-income countries. Brazil's Estratégia de Saúde da Família (ESF) (family health strategy) is a community-based primary healthcare (PHC) programme that has been expanding since the 1990s and is the main platform for delivering UHC in the country. We evaluated whether expansion of the ESF was associated with differential reductions in mortality amenable to PHC between racial groups. Municipality-level longitudinal fixed-effects panel regressions were used to examine associations between ESF coverage and mortality from ambulatory-care-sensitive conditions (ACSCs) in black/pardo (mixed race) and white individuals over the period 2000-2013. Models were adjusted for socio-economic development and wider health system variables. Over the period 2000-2013, there were 281,877 and 318,030 ACSC deaths (after age standardisation) in the black/pardo and white groups, respectively, in the 1,622 municipalities studied. Age-standardised ACSC mortality fell from 93.3 to 57.9 per 100,000 population in the black/pardo group and from 75.7 to 49.2 per 100,000 population in the white group. ESF expansion (from 0% to 100%) was associated with a 15.4% (rate ratio [RR]: 0.846; 95% CI: 0.796-0.899) reduction in ACSC mortality in the black/pardo group compared with a 6.8% (RR: 0.932; 95% CI: 0.892-0.974) reduction in the white group (coefficients significantly different, p = 0.012). These differential benefits were driven by greater reductions in mortality from infectious diseases, nutritional deficiencies and anaemia, diabetes, and cardiovascular disease in the black/pardo group. Although the analysis is ecological, sensitivity analyses suggest that over 30% of black/pardo deaths would have to be incorrectly coded for the results to be invalid. This study is limited by the use of municipal-aggregate data, which precludes individual-level inference. Omitted variable bias, where factors associated with ESF expansion are also associated with changes in mortality rates, may have influenced our findings, although sensitivity analyses show the robustness of the findings to pre-ESF trends and the inclusion of other municipal-level factors that could be associated with coverage. PHC expansion is associated with reductions in racial group inequalities in mortality in Brazil. These findings highlight the importance of investment in PHC to achieve the SDGs aimed at improving health and reducing inequalities.

Race and weight change in US women: the roles of socioeconomic and marital status.

PubMed Central

Kahn, H S; Williamson, D F; Stevens, J A

1991-01-01

BACKGROUND. The prevalence of overweight among Black women in the US is higher than among White women, but the causes are unknown. METHODS. We examined the weight change for 514 Black and 2,770 White women who entered the first Health and Nutrtion Examination Survey (1971-75) at ages 25-44 years and were weighed again a decade later. We used multivariate analyses to estimate the weight-change effectgs associated with race, family income, education, and marital change. RESULTS. After multiple adjustments, Black race, education below college level, and becoming married during the follow-up interval were each independently associated with an increased mean weight change. Using multivariate logistic analyses, Black race was not independently associated with an increased risk of major weight gain (change greater than or equal to +13 kg), but it was associated with a reduced likelihood of major weight loss (change less than or equal to -7 kg) (odds ratio - 0.64 [95% CI -0.41, 0.97])]. Very low family income was independently associated with the likelihood of both major weight gain (OR - 1.71 [95% CI - 1.15, 2.55]) and major weight loss (OR - 1.86 [95% CI - 1.18, 2.95]). CONCLUSIONS. Amont US women, Black race is independently associated with a reduced likelihood of major weight loss, but not with major weight gain. Women at greatest risk of weight gain are those with education below college level, those entering marriage, and those with very low family income. PMID:2036117

Race and weight change in US women: the roles of socioeconomic and marital status.

PubMed

Kahn, H S; Williamson, D F; Stevens, J A

1991-03-01

The prevalence of overweight among Black women in the US is higher than among White women, but the causes are unknown. We examined the weight change for 514 Black and 2,770 White women who entered the first Health and Nutrtion Examination Survey (1971-75) at ages 25-44 years and were weighed again a decade later. We used multivariate analyses to estimate the weight-change effectgs associated with race, family income, education, and marital change. After multiple adjustments, Black race, education below college level, and becoming married during the follow-up interval were each independently associated with an increased mean weight change. Using multivariate logistic analyses, Black race was not independently associated with an increased risk of major weight gain (change greater than or equal to +13 kg), but it was associated with a reduced likelihood of major weight loss (change less than or equal to -7 kg) (odds ratio - 0.64 [95% CI -0.41, 0.97])]. Very low family income was independently associated with the likelihood of both major weight gain (OR - 1.71 [95% CI - 1.15, 2.55]) and major weight loss (OR - 1.86 [95% CI - 1.18, 2.95]). Amont US women, Black race is independently associated with a reduced likelihood of major weight loss, but not with major weight gain. Women at greatest risk of weight gain are those with education below college level, those entering marriage, and those with very low family income.

Assessing black progress: voting and citizenship rights, residency and housing, education.

PubMed

Farley, R

1986-01-01

Farley discusses progress US blacks have made in the areas of voting and citizenship rights, residency and housing, and education. A major goal of the civil rights movement was to permit blacks to influence the electoral process in the same manner as whites. Most important in this regard was the Voting Rights Act of 1965; the proportion of southern blacks casting ballots increased sharply since the early 1960s. The Civil Rights Act of 1875 outlawed racial segregation in public accommodations, but by the turn of the century, Jim Crow laws in southern states called for segregation in most public places. Common customs and government policy in the North resulted in similar segregation of blacks from whites. The Montgomery bus boycott and similar protests in dozens of other cities led to enactment of Title II of the Civil Rights Act of 1964, which proscribed such racial practices. By the late 1960s, blacks in all regions could use the same public accommodations as whites. In most metropolitan areas, de facto racial segregation persisted long after the laws were changed. Supreme Court decisions and local open-housing ordinances supported the right of blacks to live where they could afford. However the major change was the Fair Housing Act of 1968, which outlawed racial discrimination in the sale or rental of most housing units. The separation of blacks from whites did not end in the 1970s. Today, in areas which have large black populations, there are many central city neighborhoods and a few in the suburbs which are either all-black or are becoming exclusively black enclaves. Most other neighborhoods have no more than token black populations. Another major effort of civil rights organizations has been the upgrading of housing quality for blacks. By 1980, only 6% of the homes and apartments occupied by blacks lacked complete plumbing facilities (down from 50% in 1940). Unlike the modest changes in residential segregation, racial differences in housing quality have been greatly reduced. By 1960, black students approached parity with whites in terms of measurable aspects of school facilities. In 1940, young blacks averaged about 3 fewer years of educational attainment than whites; the time is nearing when the years of schooling completed by blacks and whites will be the same. In small and medium-sized cities throughout the country, public schools are generally integrated. However, the situation in the largest metropolitan areas is very different. Today, large public schools are segregated, in large part, because blacks and whites live in separate school districts.

Historical Change in Occupational Frames of Reference of Black and White Southern Youth: 1966-1972.

ERIC Educational Resources Information Center

Dowdell, Randall S.

The scope of this paper covered preliminary analyses and findings on historical change in occupational aspirations, occupational expectations, and intensity and aspiration of black and white Southern youths from an East Texas rural high school. Comparisons were made by race and sex only to illuminate historical changes. Surveys of approximately…

Does Perceived Racial Discrimination Predict Changes in Psychological Distress and Substance Use over Time? An Examination among Black Emerging Adults

ERIC Educational Resources Information Center

Hurd, Noelle M.; Varner, Fatima A.; Caldwell, Cleopatra H.; Zimmerman, Marc A.

2014-01-01

We assessed whether perceived discrimination predicted changes in psychological distress and substance use over time and whether psychological distress and substance use predicted change in perceived discrimination over time. We also assessed whether associations between these constructs varied by gender. Our sample included 607 Black emerging…

Futures Thinking: Consideration of the Impact of Educational Change on Black and Minority Ethnic Achievement.

ERIC Educational Resources Information Center

Vieler-Porter, Chris

2001-01-01

Discusses the potential of information and communications technology (ICT) and the World Wide Web to offer positive alternatives in contemporary British schools that are failing their black and minority group students. Describes the advantages of ICT and looks at future changes in the teaching profession and changes in the curriculum that will…

Magnetically advected winds

NASA Astrophysics Data System (ADS)

Contopoulos, I.; Kazanas, D.; Fukumura, K.

2017-11-01

Observations of X-ray absorption lines in magnetically driven disc winds around black hole binaries and active galactic nuclei yield a universal radial density profile ρ ∝ r-1.2 in the wind. This is in disagreement with the standard Blandford and Payne profile ρBP ∝ r-1.5 expected when the magnetic field is neither advected nor diffusing through the accretion disc. In order to account for this discrepancy, we establish a new paradigm for magnetically driven astrophysical winds according to which the large-scale ordered magnetic field that threads the disc is continuously generated by the Cosmic Battery around the inner edge of the disc and continuously diffuses outward. We obtain self-similar solutions of such magnetically advected winds (MAW) and discuss their observational ramifications.

Confronting Models of Massive Star Evolution and Explosions with Remnant Mass Measurements

NASA Astrophysics Data System (ADS)

Raithel, Carolyn A.; Sukhbold, Tuguldur; Özel, Feryal

2018-03-01

The mass distribution of compact objects provides a fossil record that can be studied to uncover information on the late stages of massive star evolution, the supernova explosion mechanism, and the dense matter equation of state. Observations of neutron star masses indicate a bimodal Gaussian distribution, while the observed black hole mass distribution decays exponentially for stellar-mass black holes. We use these observed distributions to directly confront the predictions of stellar evolution models and the neutrino-driven supernova simulations of Sukhbold et al. We find strong agreement between the black hole and low-mass neutron star distributions created by these simulations and the observations. We show that a large fraction of the stellar envelope must be ejected, either during the formation of stellar-mass black holes or prior to the implosion through tidal stripping due to a binary companion, in order to reproduce the observed black hole mass distribution. We also determine the origins of the bimodal peaks of the neutron star mass distribution, finding that the low-mass peak (centered at ∼1.4 M ⊙) originates from progenitors with M ZAMS ≈ 9–18 M ⊙. The simulations fail to reproduce the observed peak of high-mass neutron stars (centered at ∼1.8 M ⊙) and we explore several possible explanations. We argue that the close agreement between the observed and predicted black hole and low-mass neutron star mass distributions provides new, promising evidence that these stellar evolution and explosion models capture the majority of relevant stellar, nuclear, and explosion physics involved in the formation of compact objects.

White fear, dehumanization, and low empathy: Lethal combinations for shooting biases.

PubMed

Mekawi, Yara; Bresin, Konrad; Hunter, Carla D

2016-07-01

A growing number of studies have documented the existence racial shooting biases against Black versus White targets (Correll et al., 2002). Little is known about individual differences that may moderate these biases. The goals of this study were to examine (a) whether White participants' fear of racial/ethnic minorities is associated with racial shooting biases, and (b) whether dehumanization and empathy moderate this effect. Participants (N = 290) completed a dehumanization implicit association test and simulated shooting task, then reported their fear of racial minorities (i.e., White fear) and empathic ability. We found that (a) individuals high in White fear showed a shooting bias, such that they had a lower threshold for shooting Black relative to White and East Asian targets, (b) Dehumanization moderated the White fear and shooting bias relation, such that individuals high in White fear and high in dehumanization had a significantly more liberal shooting threshold for Black versus White targets, and (c) Empathy moderated the White fear and shooting bias relation, such that people who were high in White fear and low in empathic ability had a more liberal shooting threshold for Black versus White targets. In sum, fearing racial/ethnic minorities can have devastating shooting bias outcomes for Black individuals, but this effect is stronger when people also dehumanize Black individuals, and weaker when people have high empathy. These findings contribute to the literature by identifying theory driven moderators that identify both risk and protective factors in predicting racial shooting biases. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The dark nemesis of galaxy formation: why hot haloes trigger black hole growth and bring star formation to an end

NASA Astrophysics Data System (ADS)

Bower, Richard G.; Schaye, Joop; Frenk, Carlos S.; Theuns, Tom; Schaller, Matthieu; Crain, Robert A.; McAlpine, Stuart

2017-02-01

Galaxies fall into two clearly distinct types: `blue-sequence' galaxies which are rapidly forming young stars, and `red-sequence' galaxies in which star formation has almost completely ceased. Most galaxies more massive than 3 × 1010 M⊙ follow the red sequence, while less massive central galaxies lie on the blue sequence. We show that these sequences are created by a competition between star formation-driven outflows and gas accretion on to the supermassive black hole at the galaxy's centre. We develop a simple analytic model for this interaction. In galaxies less massive than 3 × 1010 M⊙, young stars and supernovae drive a high-entropy outflow which is more buoyant than any tenuous corona. The outflow balances the rate of gas inflow, preventing high gas densities building up in the central regions. More massive galaxies, however, are surrounded by an increasingly hot corona. Above a halo mass of ˜1012 M⊙, the outflow ceases to be buoyant and star formation is unable to prevent the build-up of gas in the central regions. This triggers a strongly non-linear response from the black hole. Its accretion rate rises rapidly, heating the galaxy's corona, disrupting the incoming supply of cool gas and starving the galaxy of the fuel for star formation. The host galaxy makes a transition to the red sequence, and further growth predominantly occurs through galaxy mergers. We show that the analytic model provides a good description of galaxy evolution in the EAGLE hydrodynamic simulations. So long as star formation-driven outflows are present, the transition mass scale is almost independent of subgrid parameter choice.

The Accretion Disk Wind in the Black Hole GRS 1915 + 105

NASA Technical Reports Server (NTRS)

Miller, J.M.; Raymond, J.; Fabian, A. C.; Gallo, E.; Kaastra, J.; Kallman, T.; King, A. L.; Proga, D.; Reynolds, C. S.; Zoghbi, A.

2016-01-01

We report on a 120 kiloseconds Chandra/HETG spectrum of the black hole GRS 1915+105. The observation was made during an extended and bright soft state in 2015 June. An extremely rich disk wind absorption spectrum is detected, similar to that observed at lower sensitivity in 2007. The very high resolution of the third-order spectrum reveals four components to the disk wind in the Fe K band alone; the fastest has a blueshift of v = 0.03 c (velocity equals 0.03 the speed of light). Broadened reemission from the wind is also detected in the first-order spectrum, giving rise to clear accretion disk P Cygni profiles. Dynamical modeling of the re-emission spectrum gives wind launching radii of r approximately equal to 10 (sup 2-4) GM (Gravitational constant times Mass) divided by c (sup 2) (the speed of light squared). Wind density values of n approximately equal to 10 (sup 13-16) per cubic centimeter are then required by the ionization parameter formalism. The small launching radii, high density values, and inferred high mass outflow rates signal a role for magnetic driving. With simple, reasonable assumptions, the wind properties constrain the magnitude of the emergent magnetic field to be B approximately equal to 10 (sup 3-4) G (Gravitational constant) if the wind is driven via magnetohydrodynamic (MHD) pressure from within the disk and B approximately equal to 10 (sup 4-5) G (Gravitational constant) if the wind is driven by magnetocentrifugal acceleration. The MHD estimates are below upper limits predicted by the canonical alpha-disk model. We discuss these results in terms of fundamental disk physics and black hole accretion modes.

Another look at the relationship between socioeconomic factors and the black-white health benefit inequality.

PubMed

Ohn, Jonathan; McMahon, Lauren; Carter, Tony

2006-01-01

This paper illustrates the black-white disparity in health benefit coverage and the socioeconomic variables-unemployment, income, and education. The health benefit disparity is strongly related to the disparity in underlying socioeconomic variables. Moreover, the time-series examination reveals that the change in white workers' health insurance coverage is largely determined by its year-to-year persistence and the labor market tightness (or the business cycle), while that of black workers is largely determined by the change in their earnings with a slight persistence. The effect of the change in annual earnings seems to dominate the effect of the labor market condition (unemployment rate) and other variables. Finally, although marginally significant, an increase in the attainment of higher education (college) has a positive effect on the black-white health benefit disparity.

Aflatoxin-induced biochemical changes in liver of mice and its mitigation by black tea extract.

PubMed

Jha, Anamika; Shah, Komal; Verma, Ramtej J

2012-01-01

Aflatoxin belongs to the class of naturally occurring mycotoxins, food contaminants having potent carcinogenicity. We have evaluated the ameliorative role of black tea extract on aflatoxin-induced biochemical changes in the liver of albino male mice. Adult male mice were orally administered with 750 and 1500 pg of aflatoxin in 0.2 mL olive oil/kg b.w./day for 30 days. Oral administration of aflatoxin caused, as compared with controls, significant, dose-dependent reduction in DNA, RNA, protein and glycogen contents; however, cholesterol content and phsphorylase activity were significantly increased. Black tea is one of the most potent antioxidants containing numerous bioactive phytonurtients having therapeutic applications. Aflatoxin-induced changes in the liver of mice were significantly ameliorated on co-treatment of black tea extract (2% infusion in water).

Tobacco streak virus (strain dahlia) suppresses post-transcriptional gene silencing of flavone synthase II in black dahlia cultivars and causes a drastic flower color change.

PubMed

Deguchi, Ayumi; Tatsuzawa, Fumi; Hosokawa, Munetaka; Doi, Motoaki; Ohno, Sho

2015-09-01

Tobacco streak virus suppressed post-transcriptional gene silencing and caused a flower color change in black dahlias, which supported the role of cyanidin-based anthocyanins for black flower appearance. Black flower color of dahlia (Dahlia variabilis) has been attributed, in part, to the high accumulation of cyanidin-based anthocyanins that occurs when flavone synthesis is reduced because of post-transcriptional gene silencing (PTGS) of flavone synthase II (DvFNS). There are also purple-flowering plants that have emerged from a black cultivar 'Kokucho'. We report that the purple color is not caused by a mutation, as previously thought, but by infection with tobacco streak virus (TSVdahlia), which suppresses the PTGS of DvFNS. When TSVdahlia was eliminated from the purple-flowering 'Kokucho' by leaf primordia-free shoot apical meristem culture, the resulting flowers were black. TSVdahlia-infected purple flowers had lower numbers of siRNAs to DvFNS than black flowers, suggesting that TSVdahlia has a silencing suppressor. The graft inoculation of other black cultivars with TSVdahlia altered their flower color drastically except for 'Fidalgo Blacky', a very deep black cultivar with the highest amount of cyanidin-based anthocyanins. The flowers of all six TSVdahlia-infected cultivars accumulated increased amounts of flavones and reduced amounts of cyanidin-based anthocyanins. 'Fidalgo Blacky' remained black despite the change in pigment accumulation, and the amounts of cyanidin-based anthocyanins in its TSVdahlia-infected plants were still higher than those of other cultivars. We propose that black flower color in dahlia is controlled by two different mechanisms that increase the amount of cyanidin-based anthocyanins: DvFNS PTGS-dependent and -independent mechanisms. If both mechanisms occur simultaneously, the flower color will be blacker than if only a single mechanism is active.

Cosmic censorship of rotating Anti-de Sitter black hole

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gwak, Bogeun; Lee, Bum-Hoon, E-mail: rasenis@sogang.ac.kr, E-mail: bhl@sogang.ac.kr

2016-02-01

We test the validity of cosmic censorship in the rotating anti-de Sitter black hole. For this purpose, we investigate whether the extremal black hole can be overspun by the particle absorption. The particle absorption will change the mass and angular momentum of the black hole, which is analyzed using the Hamilton-Jacobi equations consistent with the laws of thermodynamics. We have found that the mass of the extremal black hole increases more than the angular momentum. Therefore, the outer horizon of the black hole still exists, and cosmic censorship is valid.

XXI century projections of wind-wave conditions and sea-level rise in the Black sea

NASA Astrophysics Data System (ADS)

Polonsky, A.; Garmashov, A.; Fomin, V.; Valchev, N.; Trifonova, E.

2012-04-01

Projection of regional climate changes for XXI century is one of the priorities of EC environmental programme. Potential worsening of the waves' statistics, sea level rise and extreme surges are the principal negative consequences of the climate change for marine environment. That is why the main purpose of this presentation is to discuss the above issue for the Black sea region (with a strong focus to the south-west subregion because the maximum heights of waves exceeding 10 m occur just here) using output of several global coupled models (GCM) for XXI century, wave simulation, long-term observations of sea level and statistical techniques. First of all we tried to choose the best coupled model (s) simulated the Black sea climate change and variability using the control experiments for 20 century (203). The principal result is as follows. There is not one model which is simulating adequately even one atmospheric parameter for all seasons. Therefore we considered (for the climate projection) different outputs form various models. When it was possible we calculated also the ensemble mean projection for the selected model (s) and emission scenarios. To calculate the wave projection we used the output of SWAN model forced by the GCM wind projection for 2010 to 2100. To estimate the sea level rise in XXI century and future surges statistics we extrapolate the observed sea level rise tendencies, statistical relation between wave heights and sea level and wave scenarios. Results show that in general, the climate change in XXI century doesn't lead to the catastrophic change of the Black sea wind-wave statistics including the extreme waves in the S-W Black sea. The typical atmospheric pattern leading to the intense storm in the S-W Black sea is characterized by the persistent anticyclonic area to the North of the Black sea and cyclonic conditions in the Southern Black sea region. Such pressure pattern causes persistent and strong eastern or north-eastern wind which generates the high waves in the S-E Black sea. The climate projections show that the frequency of such atmospheric pattern will not principally increase. The recent probability of the extreme wave height (exceeding 8 to10 m) in the S-W Black sea (~1 occurrence per 10 years) will not be much worse in XXI century. Similar conclusion is true for the storm surges along the Bulgarian coastline. Expected sea level rise in the Black sea basin for XXI century due to regional climate changes is about 2 mm per year (±50%). However, some Black sea subregions (such as Odessa and Varna bay) are characterized by fivefold sea level rise because of the local land subsidence. So, this geomorphologic effect is the most dangerous local consequence for the sustainable development and management of the coastal zone in such subregions. This study was supported by EC project "THESEUS".

X-ray astronomy in the laboratory with a miniature compact object produced by laser-driven implosion

NASA Astrophysics Data System (ADS)

Fujioka, Shinsuke; Takabe, Hideaki; Yamamoto, Norimasa; Salzmann, David; Wang, Feilu; Nishimura, Hiroaki; Li, Yutong; Dong, Quanli; Wang, Shoujun; Zhang, Yi; Rhee, Yong-Joo; Lee, Yong-Woo; Han, Jae-Min; Tanabe, Minoru; Fujiwara, Takashi; Nakabayashi, Yuto; Zhao, Gang; Zhang, Jie; Mima, Kunioki

2009-11-01

X-ray spectroscopy is an important tool for understanding the extreme photoionization processes that drive the behaviour of non-thermal equilibrium plasmas in compact astrophysical objects such as black holes. Even so, the distance of these objects from the Earth and the inability to control or accurately ascertain the conditions that govern their behaviour makes it difficult to interpret the origin of the features in astronomical X-ray measurements. Here, we describe an experiment that uses the implosion driven by a 3TW, 4kJ laser system to produce a 0.5keV blackbody radiator that mimics the conditions that exist in the neighbourhood of a black hole. The X-ray spectra emitted from photoionized silicon plasmas resemble those observed from the binary stars Cygnus X-3 (refs 7, 8) and Vela X-1 (refs 9, 10 11) with the Chandra X-ray satellite. As well as demonstrating the ability to create extreme radiation fields in a laboratory plasma, our theoretical interpretation of these laboratory spectra contrasts starkly with the generally accepted explanation for the origin of similar features in astronomical observations. Our experimental approach offers a powerful means to test and validate the computer codes used in X-ray astronomy.

Biomass changes and trophic amplification of plankton in a warmer ocean.

PubMed

Chust, Guillem; Allen, J Icarus; Bopp, Laurent; Schrum, Corinna; Holt, Jason; Tsiaras, Kostas; Zavatarelli, Marco; Chifflet, Marina; Cannaby, Heather; Dadou, Isabelle; Daewel, Ute; Wakelin, Sarah L; Machu, Eric; Pushpadas, Dhanya; Butenschon, Momme; Artioli, Yuri; Petihakis, George; Smith, Chris; Garçon, Veronique; Goubanova, Katerina; Le Vu, Briac; Fach, Bettina A; Salihoglu, Baris; Clementi, Emanuela; Irigoien, Xabier

2014-07-01

Ocean warming can modify the ecophysiology and distribution of marine organisms, and relationships between species, with nonlinear interactions between ecosystem components potentially resulting in trophic amplification. Trophic amplification (or attenuation) describe the propagation of a hydroclimatic signal up the food web, causing magnification (or depression) of biomass values along one or more trophic pathways. We have employed 3-D coupled physical-biogeochemical models to explore ecosystem responses to climate change with a focus on trophic amplification. The response of phytoplankton and zooplankton to global climate-change projections, carried out with the IPSL Earth System Model by the end of the century, is analysed at global and regional basis, including European seas (NE Atlantic, Barents Sea, Baltic Sea, Black Sea, Bay of Biscay, Adriatic Sea, Aegean Sea) and the Eastern Boundary Upwelling System (Benguela). Results indicate that globally and in Atlantic Margin and North Sea, increased ocean stratification causes primary production and zooplankton biomass to decrease in response to a warming climate, whilst in the Barents, Baltic and Black Seas, primary production and zooplankton biomass increase. Projected warming characterized by an increase in sea surface temperature of 2.29 ± 0.05 °C leads to a reduction in zooplankton and phytoplankton biomasses of 11% and 6%, respectively. This suggests negative amplification of climate driven modifications of trophic level biomass through bottom-up control, leading to a reduced capacity of oceans to regulate climate through the biological carbon pump. Simulations suggest negative amplification is the dominant response across 47% of the ocean surface and prevails in the tropical oceans; whilst positive trophic amplification prevails in the Arctic and Antarctic oceans. Trophic attenuation is projected in temperate seas. Uncertainties in ocean plankton projections, associated to the use of single global and regional models, imply the need for caution when extending these considerations into higher trophic levels. © 2014 John Wiley & Sons Ltd.

Bioavailability of catechins from tea: the effect of milk.

PubMed

van het Hof, K H; Kivits, G A; Weststrate, J A; Tijburg, L B

1998-05-01

To assess the blood concentration of catechins following green or black tea ingestion and the effect of addition of milk to black tea. Twelve volunteers received a single dose of green tea, black tea and black tea with milk in a randomized cross-over design with one-week intervals. Blood samples were drawn before and up to eight hours after tea consumption. The study was performed at the Unilever Research Vlaardingen in The Netherlands. Twelve healthy adult volunteers (7 females, 5 males) participated in the study. They were recruited among employees of Unilever Research Vlaardingen. Green tea, black tea and black tea with semi-skimmed milk (3 g tea solids each). Consumption of green tea (0.9 g total catechins) or black tea (0.3 g total catechins) resulted in a rapid increase of catechin levels in blood with an average maximum change from baseline (CVM) of 0.46 micromol/l (13%) after ingestion of green tea and 0.10 micromol/l (13%) in case of black tea. These maximum changes were reached after (mean (s.e.m.)) t=2.3 h (0.2) and t=2.2 h (0.2) for green and black tea respectively. Blood levels rapidly declined with an elimination rate (mean (CVM)) of t1/2=4.8 h (5%) for green tea and t1/2=6.9 h (8%) for black tea. Addition of milk to black tea (100 ml in 600 ml) did not significantly affect the blood catechin levels (areas under the curves (mean (CVM) of 0.53 h. micromol/l (11%) vs 0.60 h. micromol/l (9%) for black tea and black tea with milk respectively. Catechins from green tea and black tea are rapidly absorbed and milk does not impair the bioavailability of tea catechins.

Am I Still too Black for You?: Schooling and Secular Change in Skin Tone Effects

ERIC Educational Resources Information Center

Loury, Linda Datcher

2009-01-01

Analysts disagree about whether the Civil Rights/Black Power eras lessened the influence of skin tone on education. The paper finds that, holding family background constant, the educational disadvantages of dark and very dark blacks persisted between younger and older age cohorts. On the other hand, younger medium skin blacks no longer achieved…

Comparison between two types of improved motion-sensitized driven-equilibrium (iMSDE) for intracranial black-blood imaging at 3.0 tesla.

PubMed

Obara, Makoto; Kuroda, Kagayaki; Wang, Jinnan; Honda, Masatoshi; Yoneyama, Masami; Imai, Yutaka; Van Cauteren, Marc

2014-10-01

To investigate the image quality impact of a new implementation of the improved motion-sensitized driven-equilibrium (iMSDE) pulse scheme in the human brain at 3.0 Tesla. Two iMSDE preparation schemes were compared; (a) iMSDE-1: two refocusing pulses and two pairs of bipolar gradients and (b) iMSDE-2: adding extra bipolar gradients in front of the iMSDE-1 preparation. Computer simulation was used to evaluate the difference of eddy currents effect between these two approaches. Five healthy volunteers were then scanned with both sequences in the intracranial region and signal changes associated with iMSDE-1 and iMSDE-2 were assessed and compared quantitatively and qualitatively. Simulation results demonstrated that eddy currents are better compensated in iMSDE-2 than in the iMSDE-1 design. In vivo comparison showed that the iMSDE-2 sequence significantly reduced the tissue signal loss at all locations compared with iMSDE-1 (5.0% versus 23% in average, P < 0.0002 at paired t-test). The signal in iMSDE-1 showed greater spatial inhomogeneity than that of iMSDE-2. Our results show that iMSDE-2 demonstrated smaller loss in signal and less spatial variation compared with iMSDE-1, we conjecture due to the improved eddy current compensation. © 2013 Wiley Periodicals, Inc.

Acoustic black holes: recent developments in the theory and applications.

PubMed

Krylov, Victor

2014-08-01

Acoustic black holes are relatively new physical objects that have been introduced and investigated mainly during the last decade. They can absorb almost 100% of the incident wave energy, and this makes them very attractive for such traditional engineering applications as vibration damping in different engineering structures and sound absorption in gases and liquids. They also could be useful for some ultrasonic devices using Lamb wave propagation to provide anechoic termination for such waves. So far, acoustic black holes have been investigated mainly for flexural waves in thin plates, for which the required gradual changes in local wave velocity with distance can be easily achieved by changing the plates' local thickness. The present paper provides a brief review of the theory of acoustic black holes, including their comparison with optic black holes introduced about five years ago. Review is also given of the recent experimental work carried out at Loughborough University on damping structural vibrations using the acoustic black hole effect. This is followed by the discussion on potential applications of the acoustic black hole effect for sound absorption in air.

Correlated continuous time random walk and option pricing

NASA Astrophysics Data System (ADS)

Lv, Longjin; Xiao, Jianbin; Fan, Liangzhong; Ren, Fuyao

2016-04-01

In this paper, we study a correlated continuous time random walk (CCTRW) with averaged waiting time, whose probability density function (PDF) is proved to follow stretched Gaussian distribution. Then, we apply this process into option pricing problem. Supposing the price of the underlying is driven by this CCTRW, we find this model captures the subdiffusive characteristic of financial markets. By using the mean self-financing hedging strategy, we obtain the closed-form pricing formulas for a European option with and without transaction costs, respectively. At last, comparing the obtained model with the classical Black-Scholes model, we find the price obtained in this paper is higher than that obtained from the Black-Scholes model. A empirical analysis is also introduced to confirm the obtained results can fit the real data well.

Rotating Modulation Imager for the Orphan Source Search Problem

DTIC Science & Technology

2008-01-01

black mask. If the photon hits an open element it is transmitted and the function M(x) = 1. If the photon hits a closed mask element it is not...photon enters the top mask pair in the third slit, but passes through the second slit on the bottom mask. With a single black mask this is physically...modulation efficiency changes as a function of mask thickness for both tungsten and lead masks. The black line shows how the field of view changes with

The formation of bulges and black holes: lessons from a census of active galaxies in the SDSS.

PubMed

Kauffmann, Guinevere; Heckman, Timothy M

2005-03-15

We examine the relationship between galaxies, supermassive black holes and AGN using a sample of 23,000 narrow-emission-line ('type 2') active galactic nuclei (AGN) drawn from a sample of 123,000 galaxies from the Sloan Digital Sky Survey. We have studied how AGN host properties compare with those of normal galaxies and how they depend on the luminosity of the active nucleus. We find that AGN reside in massive galaxies and have distributions of sizes and concentrations that are similar to those of the early-type galaxies in our sample. The host galaxies of low-luminosity AGN have stellar populations similar to normal early types. The hosts of high- luminosity AGN have much younger mean stellar ages, and a significant fraction have experienced recent starbursts. High-luminosity AGN are also found in lower-density environments. We then use the stellar velocity dispersions of the AGN hosts to estimate black hole masses and their [OIII]lambda5007 emission-line luminosities to estimate black hole accretion rates. We find that the volume averaged ratio of star formation to black hole accretion is approximately 1000 for the bulge-dominated galaxies in our sample. This is remarkably similar to the observed ratio of stellar mass to black hole mass in nearby bulges. Most of the present-day black hole growth is occurring in black holes with masses less than 3 x 10(7)M(3). Our estimated accretion rates imply that low-mass black holes are growing on a time-scale that is comparable with the age of the Universe. Around 50% this growth takes place in AGN that are radiating within a factor of five of the Eddington luminosity. Such systems are rare, making up only 0.2% of the low-mass black hole population at the present day. The remaining growth occurs in lower luminosity AGN. The growth time-scale increases by more than an order of magnitude for the most massive black holes in our sample. We conclude that the evolution of the AGN luminosity function documented in recent optical and X-ray surveys is driven by a decrease in the characteristic mass scale of actively accreting black holes.

For blacks in America, the gap in neighborhood poverty has declined faster than segregation.

PubMed

Firebaugh, Glenn; Acciai, Francesco

2016-11-22

Black residential segregation has been declining in the United States. That accomplishment rings hollow, however, if blacks continue to live in much poorer neighborhoods than other Americans. This study uses census data for all US metropolitan areas in 1980 and 2010 to compare decline in the neighborhood poverty gap between blacks and other Americans with decline in the residential segregation of blacks. We find that both declines resulted primarily from narrowing differences between blacks and whites as opposed to narrowing differences between blacks and Hispanics or blacks and Asians. Because black-white differences in neighborhood poverty declined much faster than black-white segregation, the neighborhood poverty disadvantage of blacks declined faster than black segregation-a noteworthy finding because the narrowing of the racial gap in neighborhood poverty for blacks has gone largely unnoticed. Further analysis reveals that the narrowing of the gap was produced by change in both the medians and shapes of the distribution of poverty across the neighborhoods where blacks, whites, Hispanics, and Asians reside.

Equilibrium configurations of a charged fluid around a Kerr black hole

NASA Astrophysics Data System (ADS)

Trova, Audrey; Schroven, Kris; Hackmann, Eva; Karas, Vladimír; Kovář, Jiří; Slaný, Petr

2018-05-01

Equilibrium configurations of electrically charged perfect fluid surrounding a central rotating black hole endowed with a test electric charge and embedded in a large-scale asymptotically uniform magnetic field are presented. Following our previous studies considering the central black hole to be nonrotating, we show that in the rotating case conditions for the configurations existence change according to the spin of the black hole. We focus our attention on the charged fluid in rigid rotation, which can form toroidal configurations centered in the equatorial plane or the ones hovering above the black hole, along the symmetry axis. We conclude that a nonzero value of spin changes the existence conditions and the morphology of the solutions significantly. In the case of fast rotation, the morphology of the structures is close to an oblate shape.

Black branes in a box: hydrodynamics, stability, and criticality

NASA Astrophysics Data System (ADS)

Emparan, Roberto; Martınez, Marina

2012-07-01

We study the effective hydrodynamics of neutral black branes enclosed in a finite cylindrical cavity with Dirichlet boundary conditions. We focus on how the Gregory-Laflamme instability changes as we vary the cavity radius R. Fixing the metric at the cavity wall increases the rigidity of the black brane by hindering gradients of the redshift on the wall. In the effective fluid, this is reflected in the growth of the squared speed of sound. As a consequence, when the cavity is smaller than a critical radius the black brane becomes dynamically stable. The correlation with the change in thermodynamic stability is transparent in our approach. We compute the bulk and shear viscosities of the black brane and find that they do not run with R. We find mean-field theory critical exponents near the critical point.

Hawking Tunneling Radiation of Black Holes in de Sitter and ANTI-de Sitter Spacetimes

NASA Astrophysics Data System (ADS)

Jiang, Qing-Quan; Li, Hui-Ling; Yang, Shu-Zheng; Chen, De-You

Applying Parikh-Wilczek's semiclassical quantum tunneling method, we investigate the tunneling radiation characteristics of a torus-like black hole and Kerr-Newman-Kausya de Sitter black hole. Both black holes have the cosmological constant Λ, but a torus-like black hole is in anti-de Sitter spacetime and the other black hole is in de Sitter spacetime. The derived results show that the tunneling rate is related to the change of Bekenstein-Hawking entropy, and the factual radiated spectrum is not precisely thermal, but is consistent with an underlying unitary theory, which gives a might explanation to the paradox of black hole information lost.

Matching Changes with Changes: A Surfeit of Constructs

ERIC Educational Resources Information Center

Black, Paul

2016-01-01

Here Paul Black comments on the paper by Clark in this issue. Black first comments that the Clark paper highlights two possible factors that might effect trends of change over time. The first is that the population has become more adept at dealing with the types of challenges IQ tests present to them. Such explanations must be analyzed in light of…

Contrasting drivers and trends of coniferous and deciduous tree growth in interior Alaska.

PubMed

Cahoon, Sean M P; Sullivan, Patrick F; Brownlee, Annalis H; Pattison, Robert R; Andersen, Hans-Erik; Legner, Kate; Hollingsworth, Teresa N

2018-03-22

The boreal biome represents approximately one third of the world's forested area and plays an important role in global biogeochemical and energy cycles. Numerous studies in boreal Alaska have concluded that growth of black and white spruce is declining as a result of temperature-induced drought stress. The combined evidence of declining spruce growth and changes in the fire regime that favor establishment of deciduous tree species has led some investigators to suggest the region may be transitioning from dominance by spruce to dominance by deciduous forests and/or grasslands. Although spruce growth trends have been extensively investigated, few studies have evaluated long-term radial growth trends of the dominant deciduous species (Alaska paper birch and trembling aspen) and their sensitivity to moisture availability. We used a large and spatially extensive sample of tree cores from interior Alaska to compare long-term growth trends among contrasting tree species (white and black spruce vs. birch and aspen). All species showed a growth peak in the mid-1940s, although growth following the peak varied strongly across species. Following an initial decline from the peak, growth of white spruce showed little evidence of a trend, while black spruce and birch growth showed slight growth declines from ~1970 to present. Aspen growth was much more variable than the other species and showed a steep decline from ~1970 to present. Growth of birch, black and white spruce was sensitive to moisture availability throughout most of the tree-ring chronologies, as evidenced by negative correlations with air temperature and positive correlations with precipitation. However, a positive correlation between previous July precipitation and aspen growth disappeared in recent decades, corresponding with a rise in the population of the aspen leaf miner (Phyllocnistis populiella), an herbivorous moth, which may have driven growth to a level not seen since the early 20th century. Our results provide important historical context for recent growth and raise questions regarding competitive interactions among the dominant tree species and exchanges of carbon and energy in the warming climate of interior Alaska. © 2018 by the Ecological Society of America.

An Interview with Jim Black

ERIC Educational Resources Information Center

Burch, Brad

2006-01-01

Jim Black is president of SEM WORKS, one of the leading higher education consulting firms in the area of enrollment management. Dr. Black has delivered keynote addresses and conducted training workshops for business leaders and educators worldwide. His areas of expertise include leadership, organizational change, customer service, strategic…

The New Job Market for Black Academicians

ERIC Educational Resources Information Center

Freeman, Richard B.

1977-01-01

Analysis of data for 1969 and 1973 show that employment patterns of black college faculty members have been significantly changed, mostly through affirmative action programs, and that black male faculty, for the periods analyzed, received more job offers and higher salaries than comparable white faculty. (MF)

Regional Responses to Black Carbon Aerosols: The Importance of Air-Sea Interaction

NASA Astrophysics Data System (ADS)

Gnanadesikan, A.; Scott, A. A.; Pradal, M.-A.; Seviour, W. J. M.; Waugh, D. W.

2017-12-01

The impact of modern black carbon aerosols on climate via their changes in radiative balance is studied using a coupled model where sea surface temperatures (SSTs) are allowed to vary and an atmosphere-only version of the same model where SSTs are held fixed. Allowing the ocean to respond is shown to have a profound impact on the pattern of temperature change. Particularly, large impacts are found in the North Pacific (which cools by up to 1 K in the coupled model) and in north central Asia (which warms in the coupled simulation and cools in the fixed SST simulation). Neither set of experiments shows large changes in surface temperatures in the Southeast Asian region where the atmospheric burden of black carbon is highest. These results are related to the stabilization of the atmosphere and changes in oceanic heat transport. Over the North Pacific, atmospheric stabilization results in an increase in stratiform clouds. The resulting shading reduces evaporation, freshening the surface layer of the ocean and reducing the inflow of warm subtropical waters. Over the land, a delicate balance between greater atmospheric absorption, shading of the surface and changes in latent cooling of the surface helps to determine whether warming or cooling is seen. Our results emphasize the importance of coupling in determining the response of the climate system to black carbon and suggest that black carbon may play an important role in modulating climate change over the North Pacific.

Recent Northern Hemisphere tropical expansion primarily driven by black carbon and tropospheric ozone.

PubMed

Allen, Robert J; Sherwood, Steven C; Norris, Joel R; Zender, Charles S

2012-05-16

Observational analyses have shown the width of the tropical belt increasing in recent decades as the world has warmed. This expansion is important because it is associated with shifts in large-scale atmospheric circulation and major climate zones. Although recent studies have attributed tropical expansion in the Southern Hemisphere to ozone depletion, the drivers of Northern Hemisphere expansion are not well known and the expansion has not so far been reproduced by climate models. Here we use a climate model with detailed aerosol physics to show that increases in heterogeneous warming agents--including black carbon aerosols and tropospheric ozone--are noticeably better than greenhouse gases at driving expansion, and can account for the observed summertime maximum in tropical expansion. Mechanistically, atmospheric heating from black carbon and tropospheric ozone has occurred at the mid-latitudes, generating a poleward shift of the tropospheric jet, thereby relocating the main division between tropical and temperate air masses. Although we still underestimate tropical expansion, the true aerosol forcing is poorly known and could also be underestimated. Thus, although the insensitivity of models needs further investigation, black carbon and tropospheric ozone, both of which are strongly influenced by human activities, are the most likely causes of observed Northern Hemisphere tropical expansion.

Relativistic particle transport in hot accretion disks

NASA Technical Reports Server (NTRS)

Becker, Peter A.; Kafatos, Menas; Maisack, Michael

1994-01-01

Accretion disks around rapidly rotating black holes provide one of the few plausible models for the production of intense radiation in Acitve Galactic Nuclei (AGNs) above energies of several hundred MeV. The rapid rotation of the hole increases the binding energy per nucleon in the last stable orbit relative to the Schwarzschild case, and naturally leads to ion temperatures in the range 10(exp 12) - 10(exp 13) K for sub-Eddington accretion rates. The protons in the hot inner region of a steady, two-temperature disk form a reservoir of energy that is sufficient to power the observed Energetic Gamma Ray Experiment Telescope (EGRET) outbursts if the black hole mass is 10(exp 10) solar mass. Moreover, the accretion timescale for the inner region is comparable to the observed transient timescale of approximately 1 week. Hence EGRET outbursts may be driven by instabilities in hot, two-temperature disks around supermassive black holes. In this paper we discuss turbulent (stochastic) acceleration in hot disks as a possible source of GeV particles and radiation. We constrain the model by assuming the turbulence is powered by a collective instability that drains energy from the hot protons. We also provide some ideas concerning new, high-energy Penrose processes that produce GeV emission be directly tapping the rotational energy of Kerr black holes.

Variable intertidal temperature explains why disease endangers black abalone

USGS Publications Warehouse

Ben-Horin, Tal; Lenihan, Hunter S.; Lafferty, Kevin D.

2013-01-01

Epidemiological theory suggests that pathogens will not cause host extinctions because agents of disease should fade out when the host population is driven below a threshold density. Nevertheless, infectious diseases have threatened species with extinction on local scales by maintaining high incidence and the ability to spread efficiently even as host populations decline. Intertidal black abalone (Haliotis cracherodii), but not other abalone species, went extinct locally throughout much of southern California following the emergence of a Rickettsiales-like pathogen in the mid-1980s. The rickettsial disease, a condition known as withering syndrome (WS), and associated mortality occur at elevated water temperatures. We measured abalone body temperatures in the field and experimentally manipulated intertidal environmental conditions in the laboratory, testing the influence of mean temperature and daily temperature variability on key epizootiological processes of WS. Daily temperature variability increased the susceptibility of black abalone to infection, but disease expression occurred only at warm water temperatures and was independent of temperature variability. These results imply that high thermal variation of the marine intertidal zone allows the pathogen to readily infect black abalone, but infected individuals remain asymptomatic until water temperatures periodically exceed thresholds modulating WS. Mass mortalities can therefore occur before pathogen transmission is limited by density-dependent factors.

Statistical characteristics of breakthrough discoveries in science using the metaphor of black and white swans

NASA Astrophysics Data System (ADS)

Zeng, Carl J.; Qi, Eric P.; Li, Simon S.; Stanley, H. Eugene; Ye, Fred Y.

2017-12-01

A publication that reports a breakthrough discovery in a particular scientific field is referred to as a ;black swan;, and the most highly-cited papers previously published in the same field ;white swans;. Important scientific progress occurs when ;white swans; meet a ;black swan;, and the citation patterns of the ;white swans; change. This metaphor combines scientific discoveries and scientometric data and suggests that breakthrough scientific discoveries are either ;black swans; or ;grey-black swans;.

Effects of Religious Involvement on Parent-child Communication Regarding Schooling: A Study of Black Youth in the United States

ERIC Educational Resources Information Center

Madyun, Na'im; Lee, Moosung

2010-01-01

A growing number of Black teens are becoming religiously involved. This undoubtedly intersects with another trend in Black communities, the changing structure of the Black family. Research has shown that school-related dialogue between parent and child is an important factor in educational outcomes. This study set out to determine if there might…

The SimpleMix study with biphasic insulin aspart 30: a randomized controlled trial investigating patient-driven titration versus investigator-driven titration.

PubMed

Gao, Yan; Luquez, Cecilia; Lynggaard, Helle; Andersen, Henning; Saboo, Banshi

2014-12-01

The study aimed to confirm the efficacy, through non-inferiority, of patient-driven versus investigator-driven titration of biphasic insulin aspart 30 (BIAsp 30) in terms of glycemic control assessed by HbA1c change. SimpleMix was a 20 week, open-label, randomized, two-armed, parallel-group, multicenter study in five countries (Argentina, China, India, Poland, and the UK). Patients with type 2 diabetes were randomized into either patient-driven or investigator-driven BIAsp 30 titration groups. Non-inferiority of patient-driven vs. investigator-driven titration based on change in HbA1c from baseline to week 20 could not be demonstrated. Mean (SE) estimated change from baseline to week 20 was -0.72 (0.08)% in the patient-driven group and -0.97 (0.08)% in the investigator-driven group; estimated difference 0.25% (95% CI: 0.04; 0.46). Estimated mean change (SE) in fasting plasma glucose from baseline to week 20 was similar between groups: -0.94 (0.21) mmol/L for patient-driven and -1.07 (0.22) mmol/L for investigator-driven (difference non-significant). Both treatment arms were well tolerated, and hypoglycemic episode rates were similar between groups, with a rate ratio of 0.77 (95% CI: 0.54; 1.09; p = 0.143) for all hypoglycemic episodes and 0.78 (95% CI: 0.42; 1.43; p = 0.417) for nocturnal hypoglycemic episodes. Non-inferiority of patient-driven versus investigator-driven titration with regard to change from baseline to end-of-treatment HbA1c could not be confirmed. It is possible that a clinic visit 12 weeks after intensification of treatment with BIAsp 30 in patients with type 2 diabetes inadequately treated with basal insulin may benefit patient-driven titration of BIAsp 30. A limitation of the study was the relatively small number of patients recruited in each country, which does not allow country-specific analyses to be performed. Overall, treatment with BIAsp 30 was well tolerated in both treatment groups.

When smoke gets in our eyes: the multiple impacts of atmospheric black carbon on climate, air quality and health.

PubMed

Highwood, Eleanor J; Kinnersley, Robert P

2006-05-01

With both climate change and air quality on political and social agendas from local to global scale, the links between these hitherto separate fields are becoming more apparent. Black carbon, largely from combustion processes, scatters and absorbs incoming solar radiation, contributes to poor air quality and induces respiratory and cardiovascular problems. Uncertainties in the amount, location, size and shape of atmospheric black carbon cause large uncertainty in both climate change estimates and toxicology studies alike. Increased research has led to new effects and areas of uncertainty being uncovered. Here we draw together recent results and explore the increasing opportunities for synergistic research that will lead to improved confidence in the impact of black carbon on climate change, air quality and human health. Topics of mutual interest include better information on spatial distribution, size, mixing state and measuring and monitoring.

Defining Social Class Across Time and Between Groups.

PubMed

Cohen, Dov; Shin, Faith; Liu, Xi; Ondish, Peter; Kraus, Michael W

2017-11-01

We examined changes over four decades and between ethnic groups in how people define their social class. Changes included the increasing importance of income, decreasing importance of occupational prestige, and the demise of the "Victorian bargain," in which poor people who subscribed to conservative sexual and religious norms could think of themselves as middle class. The period also saw changes (among Whites) and continuity (among Black Americans) in subjective status perceptions. For Whites (and particularly poor Whites), their perceptions of enhanced social class were greatly reduced. Poor Whites now view their social class as slightly but significantly lower than their poor Black and Latino counterparts. For Black respondents, a caste-like understanding of social class persisted, as they continued to view their class standing as relatively independent of their achieved education, income, and occupation. Such achievement indicators, however, predicted Black respondents' self-esteem more than they predicted self-esteem for any other group.

How to Quantify Human-environment Interactions in the Past: A Global Historical Land Use Data Set for the Holocene

NASA Astrophysics Data System (ADS)

Klein Goldewijk, K.

2015-12-01

Land use plays an important role in the climate system. Many ecosystem processes are directly or indirectly climate driven, and together with human driven land use changes, they determine how the land surface will evolve through time. To assess the effects of land cover changes on the climate system, models are required which are capable of simulating interactions between the involved components of the Earth system. Since driving forces for global environmental change differ among regions, a geographically (spatially) explicit modeling approach is called for, so that it can be incorporated in global and regional (climate and/or biophysical) change models in order to enhance our understanding of the underlying processes and thus improving future projections.Some researchers suggest that mankind has shifted from living in the Holocene (~emergence of agriculture) into the Anthropocene (~humans capable of changing the Earth' atmosphere) since the start of the Industrial Revolution. But in the light of the sheer size and magnitude of some historical land use changes (e.g. the Black Plague in the 14th century and the aftermath of the Colombian Exchange in the 16th century), some believe that this point might have occurred earlier in time. There are still many uncertainties and gaps in our knowledge about the importance of land use (change) in the global biogeochemical cycle, and it is crucial that researchers from other disciplines are involved in decreasing the uncertainties.Thus, integrated records of the co-evolving human-environment system over millennia are needed to provide a basis for a deeper understanding of the present and for forecasting the future. This requires the major task of assembling and integrating regional and global historical, archaeological, and paleo-environmental records. Humans cannot predict the future. Here I present a tool for such long term global change studies; it is the latest update (v 3.2) of the History Database of the Global Environment (HYDE), which tries to incorporate many of these cross-disciplinary records and create thus new and more accurate estimates of the underlying demographic and agricultural driving factors for the whole Holocene. Estimates include population, cropland, pasture, rangeland, irrigation, rice, and built-up area.

Analysis of internal structure changes in black human hair keratin fibers resulting from bleaching treatments using Raman spectroscopy

NASA Astrophysics Data System (ADS)

Kuzuhara, Akio

2013-09-01

In order to investigate in detail the internal structure changes in virgin black human hair keratin fibers resulting from bleaching treatments, the structure of cross-sections at various depths of black human hair, which had been impossible due to high melanin grande content, was directly analyzed using Raman spectroscopy. The gauche-gauche-gauche (GGG) content of the sbnd SSsbnd groups existing from the cuticle region to the center of cortex region of the virgin black human hair remarkably decreased, while the gauche-gauche-trans and trans-gauche-trans contents were not changed by performing the excessive bleaching treatment. In particular, it was found that not only the β-sheet and/or random coil content, but also the α-helix content existing throughout the cortex region of virgin black human hair decreased. In addition, the transmission electron microscope observation shows that the proteins in the cell membrane complex, the cuticle and cortex of the virgin black human hair were remarkably eluted by performing the excessive bleaching treatment. From these experiments, the author concluded that the sbnd SSsbnd groups, which have a GGG conformation were decomposed and finally converted to cysteic acid, and the α-helix structure of some of the proteins existing in the keratin was changed to the random coil structure, or eluted from the cortex region, thereby leading to the reduction in the protein density of the virgin human hair after the excessive bleaching treatment.

Multi-scale simulations of black hole accretion in barred galaxies. Self-gravitating disk models

NASA Astrophysics Data System (ADS)

Jung, M.; Illenseer, T. F.; Duschl, W. J.

2018-06-01

Due to the non-axisymmetric potential of the central bar, in addition to their characteristic arms and bar, barred spiral galaxies form a variety of structures within the thin gas disk, such as nuclear rings, inner spirals, and dust lanes. These structures in the inner kiloparsec are extremely important in order to explain and understand the rate of black hole feeding. The aim of this work is to investigate the influence of stellar bars in spiral galaxies on the thin self-gravitating gas disk. We focus on the accretion of gas onto the central supermassive black hole and its time-dependent evolution. We conducted multi-scale simulations simultaneously resolving the galactic disk and the accretion disk around the central black hole. In all the simulations we varied the initial gas disk mass. As an additional parameter we chose either the gas temperature for isothermal simulations or the cooling timescale for non-isothermal simulations. Accretion was either driven by a gravitationally unstable or clumpy accretion disk or by energy dissipation in strong shocks. Most of the simulations show a strong dependence of the accretion rate at the outer boundary of the central accretion disk (r < 300 pc) on the gas flow at kiloparsec scales. The final black hole masses reach up to 109 M⊙ after 1.6 Gyr. Our models show the expected influence of the Eddington limit and a decline in growth rate at the corresponding sub-Eddington limit.

Tidal interaction of black holes and Newtonian viscous bodies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poisson, Eric

The tidal interaction of a (rotating or nonrotating) black hole with nearby bodies produces changes in its mass, angular momentum, and surface area. Similarly, tidal forces acting on a Newtonian, viscous body do work on the body, change its angular momentum, and part of the transferred gravitational energy is dissipated into heat. The equations that describe the rate of change of the black-hole mass, angular momentum, and surface area as a result of the tidal interaction are compared with the equations that describe how the tidal forces do work, torque, and produce heat in the Newtonian body. The equations aremore » strikingly similar, and unexpectedly, the correspondence between the Newtonian-body and black-hole results is revealed to hold in near-quantitative detail. The correspondence involves the combination k{sub 2}{tau} of 'Love quantities' that incorporate the details of the body's internal structure; k{sub 2} is the tidal Love number, and {tau} is the viscosity-produced delay between the action of the tidal forces and the body's reaction. The combination k{sub 2}{tau} is of order GM/c{sup 3} for a black hole of mass M; it does not vanish, in spite of the fact that k{sub 2} is known to vanish individually for a nonrotating black hole.« less

77 FR 6553 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-08

.... Applicants: American Electric Power Service Corporation, AEP Energy Partners, Inc., CSW Energy Services, Inc., Central and South West Services, Inc. Description: Notice of change in status of American Electric Power.... Applicants: Black Hills/Colorado Electric Utility Co, LP, Black Hills Colorado IPP, LLC, Black Hills Power...

The Future of Health Care for Blacks.

ERIC Educational Resources Information Center

Urban League Review, 1979

1979-01-01

Recommendations resulting from a 1977 conference, "Health Policy, Health Planning and Financing the Future of Health Care for Blacks in America," are presented. The recommendations concern changes in the health care system, community involvement, government regulation, the formation of Black interest groups and lobbies, and support for national…

Black Women Scientists: Outliers in South African Universities

ERIC Educational Resources Information Center

Liccardo, Sabrina; Bradbury, Jill

2017-01-01

Black women scientists are living in an important time in South Africa as the socio-political landscape is changing rapidly, effecting changes in many dimensions of identification, particularly "race", gender and class. This paper draws data from in-depth interviews with a cohort (n = 10) of Science scholarship students to explore…

Education as a Social Control Mechanism.

ERIC Educational Resources Information Center

Bacchus, M. K.

1979-01-01

With the abolition of slavery, most West Indian planters dramatically changed their attitudes toward education for Blacks, suddenly favoring it. This paper examines reasons behind the attitudinal changes, the planters' perceptions on the role of education for Blacks, and the use of education as a mechanism for social control. (DS)

The Changing Job of the President.

ERIC Educational Resources Information Center

McPhail, Irving P.

The multiple roles of a contemporary Black college president are discussed and defined, focusing on the changing role of the president. Like their White counterparts, presidents of the nation's 117 historically Black colleges have seen their roles evolve as they have become savvy promoters, competing aggressively for students and philanthropic…

Multi-Scale Residential Segregation: Black Exceptionalism and America's Changing Color Line

ERIC Educational Resources Information Center

Parisi, Domenico; Lichter, Daniel T.; Taquino, Michael C.

2011-01-01

America's changing color line is perhaps best expressed in shifting patterns of neighborhood residential segregation--the geographic separation of races. This research evaluates black exceptionalism by using the universe of U.S. blocks from the 1990 and 2000 decennial censuses to provide a "single" geographically inclusive national…

Changing Patterns of Interracial Marriage in a Multiracial Society

ERIC Educational Resources Information Center

Qian, Zhenchao; Lichter, Daniel T.

2011-01-01

We use incidence data from the 1980 Census and 2008 American Community Survey to track recent trends in interracial marriage. Intermarriage with Whites increased rapidly among Blacks but stalled among Asians and American Indians. Black-White intermarriage increased threefold over 1980-2008, independent of changing socioeconomic status, suggesting…

Patterns of Social Affiliations and Healthcare Engagement Among Young, Black, Men Who Have Sex With Men.

PubMed

Behler, Rachel L; Cornwell, Benjamin T; Schneider, John A

2018-03-01

Little work has examined how individuals' social affiliations-the venues in which they meet friends and engage in informal social interaction-influence their engagement with public health services. We investigate how links to these local places shape access to information and exposure to health-seeking behavior. Using longitudinal data from a respondent-driven sample of 618 young black men who have sex with men (YBMSM) in Chicago, we identify different sets of social venues that connect YBMSM. We then examine how YBMSM's connections within this network influence their receipt of HIV prevention and treatment services and knowledge of pre-exposure prophylaxis (PrEP). Our results show that YBMSM's positions within Chicago's venue network shape the types of health-related services they access, net of demographic, structural, and community covariates. Men with affiliations that are linked to the city's gay enclave are most likely to know about PrEP, while men with affiliations that are predominately in the black community demonstrate improved HIV treatment outcomes. Outreach engaging MSM beyond venues in gay enclaves is needed.

Americans misperceive racial economic equality

PubMed Central

Kraus, Michael W.; Rucker, Julian M.; Richeson, Jennifer A.

2017-01-01

The present research documents the widespread misperception of race-based economic equality in the United States. Across four studies (n = 1,377) sampling White and Black Americans from the top and bottom of the national income distribution, participants overestimated progress toward Black–White economic equality, largely driven by estimates of greater current equality than actually exists according to national statistics. Overestimates of current levels of racial economic equality, on average, outstripped reality by roughly 25% and were predicted by greater belief in a just world and social network racial diversity (among Black participants). Whereas high-income White respondents tended to overestimate racial economic equality in the past, Black respondents, on average, underestimated the degree of past racial economic equality. Two follow-up experiments further revealed that making societal racial discrimination salient increased the accuracy of Whites’ estimates of Black–White economic equality, whereas encouraging Whites to anchor their estimates on their own circumstances increased their tendency to overestimate current racial economic equality. Overall, these findings suggest a profound misperception of and unfounded optimism regarding societal race-based economic equality—a misperception that is likely to have any number of important policy implications. PMID:28923915

Progressive phase trends in plates with embedded acoustic black holes.

PubMed

Conlon, Stephen C; Feurtado, Philip A

2018-02-01

Acoustic black holes (ABHs) have been explored and demonstrated to be effective passive treatments for broadband noise and vibration control. Performance metrics for assessing damping concepts are often focused on maximizing structural damping loss factors. Optimally performing damping treatments can reduce the resonant response of a driven system well below the direct field response. This results in a finite structure whose vibration input-output response follows that of an infinite structure. The vibration mobility transfer functions between locations on a structure can be used to assess the structure's vibration response phase, and compare its phase response characteristics to those of idealized systems. This work experimentally explores the phase accumulation in finite plates, with and without embedded grids of ABHs. The measured results are compared and contrasted with theoretical results for finite and infinite uniform plates. Accumulated phase characteristics, their spatial dependence and limits, are examined for the plates and compared to theoretical estimates. The phase accumulation results show that the embedded acoustic black hole treatments can significantly enhance the damping of the plates to the point that their phase accumulation follows that of an infinite plate.

Perceived racism in relation to weight change in the Black Women's Health Study.

PubMed

Cozier, Yvette C; Wise, Lauren A; Palmer, Julie R; Rosenberg, Lynn

2009-06-01

Obesity is more common in black women than in white women. Racial discrimination is a form of chronic stress that may influence weight. We assessed the association of perceived racism with weight change between 1997 and 2005 in 43,103 women from the Black Women's Health Study, a prospective follow-up of U.S. black women aged 21-69 years at entry in 1995. Eight questions about perceptions and experiences of racism were asked in 1997 from which two summary variables were created: everyday racism (e.g., how often do people act "as if you are not intelligent?"), and lifetime racism (e.g., unfair treatment due to race "on the job"). Mixed linear regression models were used to calculate the multivariate adjusted means for changes in body weight across categories of perceived racism. Weight gain increased as levels of everyday and lifetime racism increased. The mean multivariable-adjusted difference in weight change between the highest and the lowest quartile of everyday racism was 0.56 kg. The mean difference comparing the highest category of lifetime racism to the lowest was 0.48 kg. These prospective data suggest that experiences of racism may contribute to the excess burden of obesity in U.S. black women.

Fermion tunneling from a non-static black hole with the internal global monopole

NASA Astrophysics Data System (ADS)

Li, Hui-Ling; Cai, Min; Lin, Rong

2009-10-01

Kerner and Mann’s recent research shows that the Hawking temperature and tunneling rate can be obtained by the fermion tunneling method from the Rindler space-time and a general non-rotating black hole. In this paper, considering the tunneling particles with spin 1/2 and taking into account the particle’s self-gravitation in the dynamical background space-time, we further improve Kerner and Man’s fermion tunneling method to investigate Hawking radiation via tunneling from a non-static black hole with the internal global monopole. The result shows that the tunneling rate of the non-static black hole is related to the integral of the changing horizon besides the change of Bekenstein-Hawking entropy, which is different from the stationary cases. It also essentially implies that the unitary is violated for the reason that the black hole is non-stationary and cannot be treated as an isolated system.

The misunderstood consequences of Shelley v. Kraemer.

PubMed

Kucheva, Yana; Sander, Richard

2014-11-01

Shelley v. Kraemer (1948) was a landmark civil rights ruling, in which the Supreme Court held that private racial covenants could not be enforced by the state to evict black buyers of "restricted" homes. Fair housing scholars have generally dismissed or downplayed the practical effects of Shelley, since other forms of housing discrimination remained very powerful. Using spatial lag models and detailed geographic data on the location of covenants and patterns of intra-urban black migration, we compare the role of Shelley with other forces shaping mid-century neighborhood change. We find that Shelley precipitated white-to-black neighborhood transitions after 1948 and changed the nature of the dual housing market in important ways. We also show that increased black mobility produced a sharp increase in intra-black economic segregation during the 1950s and 1960s. Copyright © 2014 Elsevier Inc. All rights reserved.

Topographic controls on black carbon accumulation in Alaskan black spruce forest soils: implications for organic matter dynamics

Treesearch

E.S. Kane; W.C. Hockaday; M.R. Turetsky; C.A. Masiello; D.W. Valentine; B.P. Finney; J.A. Badlock

2010-01-01

There is still much uncertainty as to how wildfire affects the accumulation of burn residues (such as black carbon [BC]) in the soil, and the corresponding changes in soil organic carbon (SOC) composition in boreal forests. We investigated SOC and BC composition in black spruce forests on different landscape positions in Alaska, USA. Mean BC stocks in surface mineral...

Black Juveniles in the Juvenile Justice System: A Cause for Alarm.

ERIC Educational Resources Information Center

LeFlore, Larry

This report examines the representation of black youth in the juvenile justice system, describes changes in juvenile justice philosophy, and discusses policy implications. Black youth are overrepresented at all stages of the juvenile justice system compared to white youth. Positivist theories explain this overrepresentation as the result of…

Representing Black Culture: Racial Conflict and Cultural Politics in the United States.

ERIC Educational Resources Information Center

Merelman, Richard M.

Recent instances of cultural conflict represent a single, broad, novel cultural tendency with real capacities to effect change. This tendency is labeled "black cultural projection." By altering American culture, black cultural projection questions entrenched patterns of political and economic domination in the United States, even though…

Black holes as parts of entangled systems

NASA Astrophysics Data System (ADS)

Basini, G.; Capozziello, S.; Longo, G.

A possible link between EPR-type quantum phenomena and astrophysical objects like black holes, under a new general definition of entanglement, is established. A new approach, involving backward time evolution and topology changes, is presented bringing to a definition of the system black hole-worm hole-white hole as an entangled system.

Blacks in Pop Music: A Short Story.

ERIC Educational Resources Information Center

Rickelman, Melinda

1991-01-01

A short history of black pop music includes artists who have changed pop music or culture and highlights from the 1920s into the 1980s, from Fats Waller to Michael Jackson. In black pop music, there is a direct line of influence from the sharecropper to the current Top 40. (SLD)

For blacks in America, the gap in neighborhood poverty has declined faster than segregation

PubMed Central

Acciai, Francesco

2016-01-01

Black residential segregation has been declining in the United States. That accomplishment rings hollow, however, if blacks continue to live in much poorer neighborhoods than other Americans. This study uses census data for all US metropolitan areas in 1980 and 2010 to compare decline in the neighborhood poverty gap between blacks and other Americans with decline in the residential segregation of blacks. We find that both declines resulted primarily from narrowing differences between blacks and whites as opposed to narrowing differences between blacks and Hispanics or blacks and Asians. Because black–white differences in neighborhood poverty declined much faster than black–white segregation, the neighborhood poverty disadvantage of blacks declined faster than black segregation—a noteworthy finding because the narrowing of the racial gap in neighborhood poverty for blacks has gone largely unnoticed. Further analysis reveals that the narrowing of the gap was produced by change in both the medians and shapes of the distribution of poverty across the neighborhoods where blacks, whites, Hispanics, and Asians reside. PMID:27821759

Increases in aerosol concentrations over eastern China due to the decadal-scale weakening of the East Asian summer monsoon

NASA Astrophysics Data System (ADS)

Zhu, Jianlei; Liao, Hong; Li, Jianping

2012-05-01

China has been experiencing increased concentrations of aerosols, commonly attributed to the large increases in emissions associated with the rapid economic development. We show by using a chemical transport model driven by the assimilated meteorological fields that the observed decadal-scale weakening of the East Asian summer monsoon also contributed to the increases in aerosols in China. We find that the simulated aerosol concentrations have strong negative correlations with the strength of the East Asian Summer monsoon. Accounting for sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols, the summer surface-layer PM2.5 concentration averaged over eastern China (110°-125°E, 20°-45°N) can be 17.7% higher in the weakest monsoon years than in the strongest monsoon years. The weakening of the East Asian Summer monsoon increases aerosol concentrations mainly by the changes in atmospheric circulation (the convergence of air pollutants) in eastern China.

Horizontal slip along Alleghanian joints of the Appalachian plateau: evidence showing that mild penetrative strain does little to change the pristine appearance of early joints

NASA Astrophysics Data System (ADS)

Engelder, Terry; Haith, Benjamin F.; Younes, Amgad

2001-07-01

Some Alleghanian joints in black shales of the Geneseo and Middlesex Formations of the Catskill Delta complex, Finger Lakes district, New York, slipped horizontally up to 8 cm. Horizontal slip is measured by the offset of ENE-striking joints. Alleghanian joints striking 330-350° display a right-lateral slip with an average value of 1.9 cm, while joints striking 004-010° slip in the left-lateral sense with an average value of 1.3 cm. The maximum horizontal stress (SH) driving this slip falls between 350° and 004°, the orientation of local Alleghanian layer-parallel shortening as indicated by both disjunctive and pencil cleavage. By commonality of orientation, we infer that slip on Alleghanian joints is driven contemporaneously with layer-parallel shortening. If so, the offset ENE-striking joints predate the Alleghanian stress field. These observations mean that both pre-Alleghanian and early Alleghanian joints persist through a period of penetrative strain.

Phases of global AdS black holes

NASA Astrophysics Data System (ADS)

Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala

2016-06-01

We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

Aerosol Absorption by Black Carbon and Dust: Implications of Climate Change and Air Quality in Asia

NASA Technical Reports Server (NTRS)

Chin, Mian

2010-01-01

Atmospheric aerosol distributions from 2000 to 2007 are simulated with the global model GOCART to attribute light absorption by aerosol to its composition and sources. We show the seasonal and interannual variations of absorbing aerosols in the atmosphere over Asia, mainly black carbon and dust. and their linkage to the changes of anthropogenic and dust emissions in the region. We compare our results with observations from satellite and ground-based networks, and estimate the importance of black carbon and dust on regional climate forcing and air quality.

AGN Obscuration Through Dusty Infrared Dominated Flows. II. Multidimensional, Radiation-Hydrodynamics Modeling

NASA Technical Reports Server (NTRS)

Dorodnitsyn, Anton; Kallman, Tim; Bisno\\vatyiI-Kogan, Gennadyi

2011-01-01

We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global ow driven by the pressure of infrared radiation on dust grains. We assume that external illumination by UV and soft X-rays of the dusty gas located at approximately 1pc away from the supermassive black hole is followed by a conversion of such radiation into IR. Using 2.5D, time-dependent radiation hydrodynamics simulations in a ux-limited di usion approximation we nd that the external illumination can support a geometrically thick obscuration via out ows driven by infrared radiation pressure in AGN with luminosities greater than 0:05 L(sub edd) and Compton optical depth, Tau(sub T) approx > & 1.

Testing the Merger Paradigm: X-ray Observations of Radio-Selected Sub-Galactic-Scale Binary AGNs

NASA Astrophysics Data System (ADS)

Fu, Hai

2016-09-01

Interactions play an important role in galaxy evolution. Strong gas inflows are expected in the process of gas-rich mergers, which may fuel intense black hole accretion and star formation. Sub-galactic-scale binary/dual AGNs thus offer elegant laboratories to study the merger-driven co-evolution phase. However, previous samples of kpc-scale binaries are small and heterogeneous. We have identified a flux-limited sample of kpc-scale binary AGNs uniformly from a wide-area high-resolution radio survey conducted by the VLA. Here we propose Chandra X-ray characterization of a subset of four radio-confirmed binary AGNs at z 0.1. Our goal is to compare their X-ray properties with those of matched control samples to test the merger-driven co-evolution paradigm.

First-order particle acceleration in magnetically driven flows

DOE PAGES

Beresnyak, Andrey; Li, Hui

2016-03-02

In this study, we demonstrate that particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. Some examples of such flows include spontaneous turbulent reconnection and decaying magnetohydrodynamic turbulence, where a magnetic field relaxes to a lower-energy configuration and transfers part of its energy to kinetic motions of the fluid. We show that this energy transfer, which normally causes turbulent cascade and heating of the fluid, also results in a first-order acceleration of non-thermal particles. Since it is generic, this acceleration mechanism is likely to play a role in the production of non-thermal particle distribution inmore » magnetically dominant environments such as the solar chromosphere, pulsar magnetospheres, jets from supermassive black holes, and γ-ray bursts.« less

Pulmonary vascular function and exercise capacity in black sub-Saharan Africans.

PubMed

Simaga, Bamodi; Vicenzi, Marco; Faoro, Vitalie; Caravita, Sergio; Di Marco, Giovanni; Forton, Kevin; Deboeck, Gael; Lalande, Sophie; Naeije, Robert

2015-09-01

Sex and age affect the pulmonary circulation. Whether there may be racial differences in pulmonary vascular function is unknown. Thirty white European Caucasian subjects (15 women) and age and body-size matched 30 black sub-Saharan African subjects (15 women) underwent a cardiopulmonary exercise test and exercise stress echocardiography with measurements of pulmonary artery pressure (PAP) and cardiac output (CO). A pulmonary vascular distensibility coefficient α was mathematically determined from the natural curvilinearity of multipoint mean PAP (mPAP)-CO plots. Maximum oxygen uptake (V̇o2max) and workload were higher in the whites, while maximum respiratory exchange ratio and ventilatory equivalents for CO2 were the same. Pulmonary hemodynamics were not different at rest. Exercise was associated with a higher maximum total pulmonary vascular resistance, steeper mPAP-CO relationships, and lower α-coefficients in the blacks. These differences were entirely driven by higher slopes of mPAP-CO relationships (2.5 ± 0.7 vs. 1.4 ± 0.7 mmHg·l(-1)·min; P < 0.001) and lower α-coefficients (0.85 ± 0.33 vs. 1.35 ± 0.51%/mmHg; P < 0.01) in black men compared with white men. There were no differences in any of the hemodynamic variables between black and white women. In men only, the slopes of mPAP-CO relationships were inversely correlated to V̇o2max (P < 0.01). Thus the pulmonary circulation is intrinsically less distensible in black sub-Saharan African men compared with white Caucasian Europeans men, and this is associated with a lower exercise capacity. This study did not identify racial differences in pulmonary vascular function in women. Copyright © 2015 the American Physiological Society.

Changes in the Aromatic Profile, Sugars, and Bioactive Compounds When Purple Garlic Is Transformed into Black Garlic.

PubMed

Martínez-Casas, Lucía; Lage-Yusty, María; López-Hernández, Julia

2017-12-13

Black garlic is an elaborated product obtained from fresh garlic (Allium sativum L.) at a controlled high humidity and temperature, which leads to modifications in color, taste, and texture. To clarify the physicochemical changes that occur during the thermal process, this work aimed to evaluate and contrast the antioxidant capacity and that of other compounds between purple garlic ecotype "Purple from Las Pedroñeras" and its black garlic derivative. Our results showed numerous differences between both, because black garlic presented a significant divergence in its volatile profile, a decreased amount of ascorbic acid, an increment in sugar and polyphenol contents, a greater antioxidant capacity, and a different composition of phenolic acids and flavonoids.

Photon orbits and thermodynamic phase transition of d -dimensional charged AdS black holes

NASA Astrophysics Data System (ADS)

Wei, Shao-Wen; Liu, Yu-Xiao

2018-05-01

We study the relationship between the null geodesics and thermodynamic phase transition for the charged AdS black hole. In the reduced parameter space, we find that there exist nonmonotonic behaviors of the photon sphere radius and the minimum impact parameter for the pressure below its critical value. The study also shows that the changes of the photon sphere radius and the minimum impact parameter can serve as order parameters for the small-large black hole phase transition. In particular, these changes have an universal exponent of 1/2 near the critical point for any dimension d of spacetime. These results imply that there may exist universal critical behavior of gravity near the thermodynamic critical point of the black hole system.

Arabian Sea tropical cyclones intensified by emissions of black carbon and other aerosols.

PubMed

Evan, Amato T; Kossin, James P; Chung, Chul Eddy; Ramanathan, V

2011-11-02

Throughout the year, average sea surface temperatures in the Arabian Sea are warm enough to support the development of tropical cyclones, but the atmospheric monsoon circulation and associated strong vertical wind shear limits cyclone development and intensification, only permitting a pre-monsoon and post-monsoon period for cyclogenesis. Thus a recent increase in the intensity of tropical cyclones over the northern Indian Ocean is thought to be related to the weakening of the climatological vertical wind shear. At the same time, anthropogenic emissions of aerosols have increased sixfold since the 1930s, leading to a weakening of the southwesterly lower-level and easterly upper-level winds that define the monsoonal circulation over the Arabian Sea. In principle, this aerosol-driven circulation modification could affect tropical cyclone intensity over the Arabian Sea, but so far no such linkage has been shown. Here we report an increase in the intensity of pre-monsoon Arabian Sea tropical cyclones during the period 1979-2010, and show that this change in storm strength is a consequence of a simultaneous upward trend in anthropogenic black carbon and sulphate emissions. We use a combination of observational, reanalysis and model data to demonstrate that the anomalous circulation, which is radiatively forced by these anthropogenic aerosols, reduces the basin-wide vertical wind shear, creating an environment more favourable for tropical cyclone intensification. Because most Arabian Sea tropical cyclones make landfall, our results suggest an additional impact on human health from regional air pollution.

Hierarchical flower-like NiAl-layered double hydroxide microspheres encapsulated with black Cu-doped TiO2 nanoparticles: Highly efficient visible-light-driven composite photocatalysts for environmental remediation.

PubMed

Jo, Wan-Kuen; Kim, Yeong-Gyeong; Tonda, Surendar

2018-05-22

Herein, highly efficient composite photocatalysts comprising black Cu-doped TiO 2 nanoparticles (BCT) encapsulated within hierarchical flower-like NiAl-layered double hydroxide (LDH) microspheres were fabricated via a one-step hydrothermal route. Cu-doping and subsequent reduction treatment led to extended visible-light absorption of TiO 2 in the resulting composites, as confirmed by ultraviolet-visible diffuse reflectance spectral analysis. Moreover, thorough investigations confirmed the strong interactions between LDH and BCT in the resulting BCT/LDH composites. Notably, the BCT/LDH composites exhibited remarkable performance in the degradation of hazardous materials (methyl orange and isoniazid), superior to that of the individual components, reference P25, and P25/LDH under visible-light irradiation. Moreover, the BCT/LDH composite containing 30 wt% of BCT displayed the highest photocatalytic performance among the synthesized photocatalysts and also exhibited high stability during recycling tests with no obvious change in the activity. The superior photodegradation activity of the BCT/LDH composites was primarily attributed to efficient transfer and separation of the photoinduced charge carriers, resulting from the intimate contact interfaces between LDH and BCT. This approach represents a promising route for the rational design of highly efficient and visible-light-active LDH-based composite photocatalysts for application in energy harvesting and environmental protection. Copyright © 2018 Elsevier B.V. All rights reserved.

Au Nanoclusters Sensitized Black TiO2-x Nanotubes for Enhanced Photodynamic Therapy Driven by Near-Infrared Light.

PubMed

Yang, Dan; Gulzar, Arif; Yang, Guixin; Gai, Shili; He, Fei; Dai, Yunlu; Zhong, Chongna; Yang, Piaoping

2017-12-01

The low reactive oxygen species production capability and the shallow tissue penetration of excited light (UV) are still two barriers in photodynamic therapy (PDT). Here, Au cluster anchored black anatase TiO 2- x nanotubes (abbreviated as Au 25 /B-TiO 2- x NTs) are synthesized by gaseous reduction of anatase TiO 2 NTs and subsequent deposition of noble metal. The Au 25 /B-TiO 2- x NTs with thickness of about 2 nm exhibit excellent PDT performance. The reduction process increased the density of Ti 3+ on the surface of TiO 2 , which effectively depresses the recombination of electron and hole. Furthermore, after modification of Au 25 nanoclusters, the PDT efficiency is further enhanced owing to the changed electrical distribution in the composite, which forms a shallow potential well on the metal-TiO 2 interface to further hamper the recombination of electron and hole. Especially, the reduction of anatase TiO 2 can expend the light response range (UV) of TiO 2 to the visible and even near infrared (NIR) light region with high tissue penetration depth. When excited by NIR light, the nanoplatform shows markedly improved therapeutic efficacy attributed to the photocatalytic synergistic effect, and promotes separation or restrained recombination of electron and hole, which is verified by experimental results in vitro and in vivo. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prescription opioid mortality trends in New York City, 1990–2006: Examining the emergence of an epidemic☆

PubMed Central

Ransome, Yusuf; Keyes, Katherine M.; Koenen, Karestan C.; Tracy, Melissa; Tardiff, Kenneth J.; Vlahov, David; Galea, Sandro

2013-01-01

Background The drug overdose mortality rate tripled between 1990 and 2006; prescription opioids have driven this epidemic. We examined the period 1990–2006 to inform our understanding of how the current prescription opioid overdose epidemic emerged in urban areas. Methods We used data from the Office of the Chief Medical Examiner to examine changes in demographic and spatial patterns in overdose fatalities induced by prescription opioids (i.e., analgesics and methadone) in New York City (NYC) in 1990–2006, and what factors were associated with death from prescription opioids vs. heroin, historically the most prevalent form of opioid overdose in urban areas. Results Analgesic-induced overdose fatalities were the only types of overdose fatalities to increase in 1990–2006 in NYC; the fatality rate increased sevenfold from 0.39 in 1990 to 2.7 per 100,000 persons in 2006. Whites and Latinos were the only racial/ethnic groups to exhibit an increase in overdose-related mortality. Relative to heroin overdose decedents, analgesic and methadone overdose decedents were more likely to be female and to concurrently use psychotherapeutic drugs, but less likely to concurrently use alcohol or cocaine. Analgesic overdose decedents were less likely to be Black or Hispanic, while methadone overdose decedents were more likely to be Black or Hispanic in contrast to heroin overdose decedents. Conclusions The distinct epidemiologic profiles exhibited by analgesic and methadone overdose fatalities highlight the need to define drug-specific public health prevention efforts. PMID:23357743

Stratospheric Aerosol--Observations, Processes, and Impact on Climate

NASA Technical Reports Server (NTRS)

Kresmer, Stefanie; Thomason, Larry W.; von Hobe, Marc; Hermann, Markus; Deshler, Terry; Timmreck, Claudia; Toohey, Matthew; Stenke, Andrea; Schwarz, Joshua P.; Weigel, Ralf;

Simulated Impacts of Emerald Ash Borer on Throughfall and Stemflow Inputs of Water and Nitrogen in Black Ash Wetlands in Northern Michigan

NASA Astrophysics Data System (ADS)

Pypker, T. G.; Davis, J.; Van Grinsven, M. J.; Bolton, N. W.; Shannon, J.; Kolka, R. K.; Nelson, J.; Wagenbrenner, J. W.

2014-12-01

Emerald ash borer (Agrilus planipennis Fairmaire (EAB)) is an invasive insect that effectively kills ash trees (genus: Fraxinus) greater than 2.5 cm in diameter, resulting in near-complete stand mortality within 3-4 years. Black ash wetlands occupy approximately 270,000 ha in Michigan, and have 40 to 90% of the basal area occupied by black ash (F. nigra Marshall); hence the loss of black ash may result in dramatic changes in the canopy hydrology and nutrient deposition. We assessed the impact of a simulated EAB invasion on throughfall and stemflow quantity and nitrogen (N) content in 9 uninfected black ash wetlands located in the Upper Peninsula of Michigan. Within the 9 stands, 3 stands were left untreated ('Control'), 3 stands had all the black ash trees manually girdled ('Girdled') and 3 had all the black ash trees felled by chainsaw ('Clearcut'). We measured the quantity and inorganic-N content of throughfall using an array of randomly placed collectors (n = 16 per site). Stemflow was monitored at 2 sites (n = 12 trees) on the 3 most common tree species (black ash, yellow birch (Betula alleghaniensis Britt.) and red maple (Acer rubra L.)). Preliminary results indicate that relative to the Control, average monthly throughfall was 25% and 1% greater in the Clearcut and Girdled sites, respectively. While the loss of the ash trees resulted in greater throughfall inputs in the Clearcut sites, water table heights did not significantly change as a result of the treatments. Stemflow from live black ash trees was lower than from the yellow birch and red maple trees. As a result, we predict stemflow will increase over time as species with smoother bark and less upright branching begin replacing the black ash. Hence, the change in tree species may result in a greater concentration of inorganic-N inputs to the base of the trees, thereby altering the distribution of inorganic-N inputs into the wetland. Our preliminary results show no significant change in the total inorganic-N deposition via throughfall. Despite the severity of the disturbance that resulted from the simulated EAB infestation, preliminary results suggest that that these wetlands may show some short-term resiliency to the impacts of ash mortality, resulting in relatively unchanged hydrologic and nutrient deposition regimes.

Topographically Driven Lateral Water Fluxes and Their Influence on Carbon Assimilation of a Black Spruce Ecosystem.

NASA Astrophysics Data System (ADS)

Govind, A.; Chen, J. M.; Margolis, H.; Bernier, P. Y.

2006-12-01

Current estimates of ecophysiological indicators overlook the effects of topographically-driven lateral flow of soil water. We hypothesize that topographically driven lateral water flows over the landscape have significant influence on the terrestrial carbon cycle. To this end, we simulated the hydrological controls on carbon cycle processes in a black spruce forest in central Quebec, Canada, using the Boreal Ecosystem Productivity Simulator (BEPS) at a daily time step. We accounted for lateral surface and subsurface flows in BEPS by incorporating a distributed, process-oriented hydrological procedure. The results show that modeled dynamics of ecophysiological processes such as evapotranspiration (ET) and photosynthesis (GPP) are consistent with the spatial variation of land cover, topography, soil texture, and leaf area index. Simulated ET and GPP averaged within the footprint of an eddy covariance tower in the watershed agree well with flux measurements with R2=0.77 and 0.83 for ET and GPP, respectively. For ET simulation, much of the remaining discrepancies are found in the winter when the model underestimates snow sublimation. For GPP, there is an underestimation in the fall coinciding with a mid growing season drought, showing the high sensitivity of the model to the soil water status. The key processes controlling primary production were hydraulic limitations for water transfer from soil, roots, stems and leaves through stomatal conductance. Therefore, a further understanding of soil water dynamics is warranted. Comparison with the soil water content of the footprint- averaged unsaturated zone showed that the model captured the annual trend. We also simulated the variations in the water table as well as the mid growing season drought, with a reasonable accuracy(R2=0.68). The foot print average water budget reveals that the annual precipitation of 835mm is partitioned into 282mm of ET, 541 mm of subsurface runoff, and 6 mm of storage change. To test the influence of topographically driven lateral water flow on the carbon cycle, we made three hydrological modeling scenarios viz. 1) explicit hydrological simulation including lateral water routing, 2) bucket model with implicit runoff calculations and 3) a control run, where the lateral water flow was turned off in the model. Bucket model overestimated GPP as much as 25% as opposed to explicit simulations because there was no topographical constrain on runoff. Flat areas dominated with mineral soils shows the highest overestimation because of an increase in stomatal conductance. Control simulation, on the other hand, underestimated GPP as much as 15% as opposed to explicit routing because of rapid soil saturation, which decreases stomatal conductance. These results suggest that lateral water flow does play a significant role in the terrestrial carbon cycle and should be accounted for in ecological models. For details please see http://ajit.govind.googlepages.com/agu2006

Combined Racial and Gender Differences in the Long-Term Predictive Role of Education on Depressive Symptoms and Chronic Medical Conditions.

PubMed

Assari, Shervin

2017-06-01

Despite a well-established literature on the protective effect of education on health, less is known about group differences in the mechanisms underlying this association. Using a life course approach and cumulative advantage theory, this study compared Black men, Black women, White men, and White women to assess the long-term gradient (education as a continuous measure) and threshold (>12 years) effects of baseline education on change in chronic medical conditions (CMC) and depressive symptoms (DS) from baseline to 25 years later. Data came from the Americans' Changing Lives Study, 1986-2011. The study followed Black and White respondents for up to 25 years, among whom 1271 individuals who had survived and were under follow-up were interviewed in 2011 and reported their number of chronic medical conditions and depressive symptoms (Center for Epidemiological Studies-Depression; CES-D 11). Multi-group structural equation modeling was used to compare gradient and threshold effects of education on change in chronic medical conditions and depressive symptoms from baseline (1986) to 25 years later (2011) among Black men, Black women, White men, and White women. There were group differences in the long-term association between education measured as a gradient and the change in depressive symptoms and chronic medical conditions during the follow-up, and in the association between education measured at the threshold of 12 years on change in depressive symptoms from baseline to follow-up. However, the association between education measured at this threshold and change in chronic medical conditions did not differ across race-gender groups. With the exception of Black men, who showed a gradient protective effect for baseline education against increase in the number of chronic medical associations (threshold or gradient) with change in chronic medical conditions. Among White men and White women, education had a threshold protective effect against increase in depressive symptoms from baseline to 25 years later. Black men and women showed a gradient protective effect of baseline education against an increase in depressive symptoms over the 25-year follow-up period, but unexpectedly, a threshold effect of education was also found to be associated with an increase in depressive symptoms over the follow-up period among Black men. This finding suggests that although Black men benefit from each incremental increase in education, those who graduated from high school were at an additional risk of depressive symptoms over a 25-year period. Findings suggest that the intersection of race and gender influences how education is associated with long-term changes in physical and mental health of individuals from baseline to 25 years later. As the shape of the association between education and health depends on the intersection of race and gender, these groups may vary for operant mechanisms by which education operates as a main social determinant of health.

Textual Transformations in Contemporary Black Writing in Britain

ERIC Educational Resources Information Center

Dhouib, Jawhar Ahmed

2014-01-01

While the first wave of Caribbean immigrant writers brilliantly explored race-related issues, black Britons like Andrea Levy, Zadie Smith and Caryl Phillips, among others, have sought to depart from earlier fiction, motivated in their project by the changing white face of Britain. In this article, I would like to argue that cultural change in…

Partial dust obscuration in active galactic nuclei as a cause of broad-line profile and lag variability, and apparent accretion disc inhomogeneities

NASA Astrophysics Data System (ADS)

Gaskell, C. Martin; Harrington, Peter Z.

2018-04-01

The profiles of the broad emission lines of active galactic nuclei (AGNs) and the time delays in their response to changes in the ionizing continuum ("lags") give information about the structure and kinematics of the inner regions of AGNs. Line profiles are also our main way of estimating the masses of the supermassive black holes (SMBHs). However, the profiles often show ill-understood, asymmetric structure and velocity-dependent lags vary with time. Here we show that partial obscuration of the broad-line region (BLR) by outflowing, compact, dusty clumps produces asymmetries and velocity-dependent lags similar to those observed. Our model explains previously inexplicable changes in the ratios of the hydrogen lines with time and velocity, the lack of correlation of changes in line profiles with variability of the central engine, the velocity dependence of lags, and the change of lags with time. We propose that changes on timescales longer than the light-crossing time do not come from dynamical changes in the BLR, but are a natural result of the effect of outflowing dusty clumps driven by radiation pressure acting on the dust. The motion of these clumps offers an explanation of long-term changes in polarization. The effects of the dust complicate the study of the structure and kinematics of the BLR and the search for sub-parsec SMBH binaries. Partial obscuration of the accretion disc can also provide the local fluctuations in luminosity that can explain sizes deduced from microlensing.

Knowledge-driven institutional change: an empirical study on combating desertification in northern China from 1949 to 2004.

PubMed

Yang, Lihua; Wu, Jianguo

2012-11-15

Understanding institutional changes is crucial for environmental management. Here we investigated how institutional changes influenced the process and result of desertification control in northern China between 1949 and 2004. Our analysis was based on a case study of 21 field sites and a meta-analysis of additional 29 sites reported in the literature. Our results show that imposed knowledge-driven institutional change was often perceived as a more progressive, scientific, and rational type of institutional change by entrepreneurs, scholars, experts, and technicians, while voluntary, knowledge-driven institutional change based on indigenous knowledge and experiences of local populations was discouraged. Our findings also demonstrate that eight working rules of imposed knowledge-driven institutional change can be applied to control desertification effectively. These rules address the issues of perception of potential gains, entrepreneurs' appeals and support, coordination of multiple goals, collaboration among multiple organizations, interest distribution and conflict resolution, incremental institutional change, external intervention, and coordination among the myriad institutions involved. Imposed knowledge-driven institutional change tended to be more successful when these rules were thoroughly implemented. These findings provide an outline for implementing future institutional changes and policy making to combat desertification and other types of ecological and environmental management. Copyright © 2012 Elsevier Ltd. All rights reserved.

Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.

PubMed

Liang, Tingfu; Wei, Feifei; Lu, Yi; Kodani, Yoshinori; Nakada, Mitsuhiko; Miyakawa, Takuya; Tanokura, Masaru

2015-01-21

Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.

Two strikes: race and the disciplining of young students.

PubMed

Okonofua, Jason A; Eberhardt, Jennifer L

2015-05-01

There are large racial disparities in school discipline in the United States, which, for Black students, not only contribute to school failure but also can lay a path toward incarceration. Although the disparities have been well documented, the psychological mechanisms underlying them are unclear. In two experiments, we tested the hypothesis that such disparities are, in part, driven by racial stereotypes that can lead teachers to escalate their negative responses to Black students over the course of multiple interpersonal (e.g., teacher-to-student) encounters. More generally, we argue that race not only can influence how perceivers interpret a specific behavior, but also can enhance perceivers' detection of behavioral patterns across time. Finally, we discuss the theoretical and practical benefits of employing this novel approach to stereotyping across a range of real-world settings. © The Author(s) 2015.

Active galactic nucleus outflows in galaxy discs

NASA Astrophysics Data System (ADS)

Hartwig, Tilman; Volonteri, Marta; Dashyan, Gohar

2018-05-01

Galactic outflows, driven by active galactic nuclei (AGNs), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many, if not most, gas-rich galaxies cold gas is rotationally supported and settles in a disc. We present a 2D analytical model for AGN-driven outflows in a gaseous disc and demonstrate the main improvements, compared to existing 1D solutions. We find significant differences for the outflow dynamics and wind efficiency. The outflow is energy-driven due to inefficient cooling up to a certain AGN luminosity (˜1043 erg s-1 in our fiducial model), above which the outflow remains momentum-driven in the disc up to galactic scales. We reproduce results of 3D simulations that gas is preferentially ejected perpendicular to the disc and find that the fraction of ejected interstellar medium is lower than in 1D models. The recovery time of gas in the disc, defined as the free-fall time from the radius to which the AGN pushes the ISM at most, is remarkably short, of the order 1 Myr. This indicates that AGN-driven winds cannot suppress BH growth for long. Without the inclusion of supernova feedback, we find a scaling of the BH mass with the halo velocity dispersion of MBH ∝ σ4.8.

Black Voting during the Civil Rights Movement: A Micro-Level Analysis

ERIC Educational Resources Information Center

Beyerlein, Kraig; Andrews, Kenneth T.

2008-01-01

This article examines why some black Southerners but not others were politically active during the early stages of the civil rights movement. Using a survey of more than 600 black Southerners in 1961, we investigate whether perceptions about opportunity or threat, politicized social capital and individual orientations toward social change shaped…

MCD Process Model: A Systematic Approach to Curriculum Development in Black Studies.

ERIC Educational Resources Information Center

Miller, Howard J.

1986-01-01

Holds that Black Studies programs have had problems surviving because of (1) resistance to curriculum change in colleges and universities, (2) their lack of supporters in positions of administrative power, and (3) lack of an organized, conceptual approach to developing and implementing a Black Studies curriculum. Presents a model designed to…

Inside the Black Box of Classroom Practice: Change without Reform in American Education

ERIC Educational Resources Information Center

Cuban, Larry

2013-01-01

A book that explores the problematic connection between education policy and practice while pointing in the direction of a more fruitful relationship, "Inside the Black Box of Classroom Practice" is a provocative culminating statement from one of America's most insightful education scholars and leaders. "Inside the Black Box of…

Exploration of Culturally Proficient Mental Health Assessment and Treatment Practices of Black/African American Clients

ERIC Educational Resources Information Center

Glover, Tina Marie

2012-01-01

Changing trends within the mental health system treatment practices demand exploration of the cultural context of assessment and treatment of Black/African Americans. Culturally competent assessments include a realistic integration of historical context. Clinicians counseling Black/African Americans must be prepared to assess and address PTSD,…

Racial Identity and Depressive Symptoms among Black Emerging Adults: The Moderating Effects of Neighborhood Racial Composition

ERIC Educational Resources Information Center

Hurd, Noelle M.; Sellers, Robert M.; Cogburn, Courtney D.; Butler-Barnes, Sheretta T.; Zimmerman, Marc A.

2013-01-01

In the current study, we explored patterns of change in Black emerging adults' racial identity beliefs during the transition to adulthood, assessed neighborhood racial composition effects on Black emerging adults' racial identity beliefs, and tested the moderating effects of neighborhood racial composition on the associations between Black…

The Lily-White University Presses.

ERIC Educational Resources Information Center

Shin, Annys

1996-01-01

Argues that the university presses are immune from racial change and discusses the problem of using location as an argument for not being able to lure blacks into university publishing. Howard University Press is used to illustrate the problem of budget cutting and the ability to boost black recruitment efforts or establish a united black press…

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.

Gas Flows in Dual Active Galactic Nuclei

NASA Astrophysics Data System (ADS)

Mueller Sanchez, Francisco; Comerford, Julia M.; Davies, Richard; Treister, Ezequiel; Privon, George C.; Nevin, Becky

2018-06-01

Dual Active Galactic Nuclei (AGN) are the Rosetta stone to understand the role of galaxy mergers in triggering nuclear activity and regulating black hole (BH) and galaxy growth. But very little is known about the physical processes required to effectively trigger AGN activity and regulate the growth of the two BHs. The work I will present here characterizes for the first time the properties of the stars, gas (molecular, ionized, and highly-ionized) and dust in all the confirmed dual AGN at z < 0.05, using Keck/OSIRIS, VLT/SINFONI, SOFIA/FORCAST, and HST data. I will focus on the interplay between the several complex processes observed in dual AGN, using as an example the prototypical merger system NGC 6240: vigorous star formation, two AGNs, outflowing winds of ionized gas, rippling dust and gas lanes, and tidal tails. In this galaxy, we observe for the first time a dual outflow of different species of gas: an AGN-driven outflow of highly-ionized gas to the northeast and a starburst-driven outflow of ionized hydrogen to the northwest. This shows that stellar feedback and supermassive black hole feedback can work in tandem to regulate the stellar growth of a galaxy after a merger event. These results open a new door to studies of dual AGN and AGN pairs in general, and enable dual AGN to be used, for the first time, for studies of galaxy evolution.

Senile macular changes in the black African.

PubMed Central

Gregor, Z.; Joffe, L.

1978-01-01

One thousand black African and 380 white Caucasian patients over the age of 50 were examined for evidence of age-related macular changes, namely, drusen, pigment epithelial atrophy, and disciform macular degeneration. Drusen and pigment epithelial changes were found to occur twice as commonly in Caucasians as in Africans; there was a much greater difference in the prevalence of disciform macular degeneration between the 2 groups. The cause of the differences remains unexplained. PMID:687553

Proteomic Analysis Reveals Coordinated Regulation of Anthocyanin Biosynthesis through Signal Transduction and Sugar Metabolism in Black Rice Leaf.

PubMed

Chen, Linghua; Huang, Yining; Xu, Ming; Cheng, Zuxin; Zheng, Jingui

2017-12-15

Black rice ( Oryza sativa L.) is considered to be a healthy food due to its high content of anthocyanins in the pericarp. The synthetic pathway of anthocyanins in black rice grains has been identified, however, the proteomic profile of leaves during grain development is still unclear. Here, isobaric Tags Relative and Absolute Quantification (iTRAQ) MS/MS was carried out to identify statistically significant changes of leaf proteome in the black rice during grain development. Throughout three sequential developmental stages, a total of 3562 proteins were detected and 24 functional proteins were differentially expressed 3-10 days after flowering (DAF). The detected proteins are known to be involved in various biological processes and most of these proteins were related to gene expression regulatory (33.3%), signal transduction (16.7%) and developmental regulation and hormone-like proteins (12.5%). The coordinated changes were consistent with changes in regulatory proteins playing a leading role in leaves during black rice grain development. This indicated that signal transduction between leaves and grains may have an important role in anthocyanin biosynthesis and accumulation during grain development of black rice. In addition, four identified up-regulated proteins associated with starch metabolism suggested that the remobilization of nutrients for starch synthesis plays a potential role in anthocyanin biosynthesis of grain. The mRNA transcription for eight selected proteins was validated with quantitative real-time PCR. Our results explored the proteomics of the coordination between leaf and grain in anthocyanins biosynthesis of grain, which might be regulated by signal transduction and sugar metabolism in black rice leaf.

Potential species replacements for black ash (Fraxinus nigra) at the confluence of two threats: Emerald ash borer and a changing climate

Treesearch

Louis Iverson; Kathleen S. Knight; Anantha Prasad; Daniel A. Herms; Stephen Matthews; Matthew Peters; Annemarie Smith; Diane M. Hartzler; Robert Long; John Almendinger

2015-01-01

The emerald ash borer (Agrilus planipennis; EAB) is causing widespread mortality of ash (Fraxinus spp.) and climate change is altering habitats of tree species throughout large portions of North America. Black ash (F. nigra), a moist-soil species common in the Northwoods of Minnesota, Wisconsin, and...

Interpersonal Attraction Toward a Black Person as a Function of Value Importance.

ERIC Educational Resources Information Center

Penner, Louis A.

The purpose of this study was to test two hypotheses derived from Rokeach's (1968) theory of values and value change. These were: (1) that interpersonal attraction toward a black person will be correlated with the importance of the value, "equality," and (2) that changes in the importance of the value, "equality," will be…

Effects of a landscape disturbance on the habitat use and behavior of the black racer

Treesearch

Christopher A. F. Howey; Matthew B. Dickinson; Willem M. Roosenburg

2016-01-01

The effects of disturbance, including prescribed fire, vary among species and their ability to adjust to the altered environment. Our objective was to link fire-caused habitat changes with shifts in habitat use and behavioral changes in the Southern Black Racer (Coluber constrictor priapus). We compared habitat availability between burned (...

Curricular Changes to Meet the Needs of a Black Society.

ERIC Educational Resources Information Center

Hamilton, Charles V.

The turmoil on college campuses today that centers around the protest demands of black students clearly points to the need for substantive curricular changes. Many students are interested in "relevant" courses which, to them, means moving out of the ivory tower and "into the community." Classroom studies could be linked to ghetto problems in…

Association between expansion of primary healthcare and racial inequalities in mortality amenable to primary care in Brazil: A national longitudinal analysis

PubMed Central

Rasella, Davide; Millett, Christopher

2017-01-01

Background Universal health coverage (UHC) can play an important role in achieving Sustainable Development Goal (SDG) 10, which addresses reducing inequalities, but little supporting evidence is available from low- and middle-income countries. Brazil’s Estratégia de Saúde da Família (ESF) (family health strategy) is a community-based primary healthcare (PHC) programme that has been expanding since the 1990s and is the main platform for delivering UHC in the country. We evaluated whether expansion of the ESF was associated with differential reductions in mortality amenable to PHC between racial groups. Methods and findings Municipality-level longitudinal fixed-effects panel regressions were used to examine associations between ESF coverage and mortality from ambulatory-care-sensitive conditions (ACSCs) in black/pardo (mixed race) and white individuals over the period 2000–2013. Models were adjusted for socio-economic development and wider health system variables. Over the period 2000–2013, there were 281,877 and 318,030 ACSC deaths (after age standardisation) in the black/pardo and white groups, respectively, in the 1,622 municipalities studied. Age-standardised ACSC mortality fell from 93.3 to 57.9 per 100,000 population in the black/pardo group and from 75.7 to 49.2 per 100,000 population in the white group. ESF expansion (from 0% to 100%) was associated with a 15.4% (rate ratio [RR]: 0.846; 95% CI: 0.796–0.899) reduction in ACSC mortality in the black/pardo group compared with a 6.8% (RR: 0.932; 95% CI: 0.892–0.974) reduction in the white group (coefficients significantly different, p = 0.012). These differential benefits were driven by greater reductions in mortality from infectious diseases, nutritional deficiencies and anaemia, diabetes, and cardiovascular disease in the black/pardo group. Although the analysis is ecological, sensitivity analyses suggest that over 30% of black/pardo deaths would have to be incorrectly coded for the results to be invalid. This study is limited by the use of municipal-aggregate data, which precludes individual-level inference. Omitted variable bias, where factors associated with ESF expansion are also associated with changes in mortality rates, may have influenced our findings, although sensitivity analyses show the robustness of the findings to pre-ESF trends and the inclusion of other municipal-level factors that could be associated with coverage. Conclusions PHC expansion is associated with reductions in racial group inequalities in mortality in Brazil. These findings highlight the importance of investment in PHC to achieve the SDGs aimed at improving health and reducing inequalities. PMID:28557989

Comparing young and older adults' perceptions of conflicting stereotypes and multiply-categorizable individuals.

PubMed

Kang, Sonia K; Chasteen, Alison L; Cadieux, Jonathan; Cary, Lindsey A; Syeda, Maisha

2014-09-01

Individuals can be simultaneously categorized into multiple social groups (e.g., racial, gender, age), and stereotypes about one social group may conflict with another. Two such conflicting stereotype sets are those associated with older adults (e.g., frail, kind) and with Black people (e.g., violent, hostile). Recent research shows that young adult perceivers evaluate elderly Black men more positively than young Black men, suggesting that components of the elderly stereotype moderate the influence of conflicting Black stereotypes (Kang & Chasteen, 2009). The current research begins to examine whether this pattern of perceiving multiply-categorizable individuals is maintained among older adults or altered, perhaps due to aging-related cognitive and motivational changes. In three studies using different targets and evaluative tasks, both young and older participants showed evidence of an interplay between Black and elderly stereotypes, such that they perceived elderly Black targets more positively than young Black targets. A similar pattern was observed when assessing emotion change (Study 1), making ratings of warmth and power in the past, present, and future (Study 2), and when directly comparing young and old Black and White targets on traits related to warmth and power (Study 3). The absence of age differences suggests that evaluation of multiply-categorizable targets follows comparable underlying patterns of stereotype activation and inhibition in younger and older adults. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Assessing climate change impacts on wetlands in a flow regulated catchment: A case study in the Macquarie Marshes, Australia.

PubMed

Fu, Baihua; Pollino, Carmel A; Cuddy, Susan M; Andrews, Felix

2015-07-01

Globally wetlands are increasingly under threat due to changes in water regimes as a result of river regulation and climate change. We developed the Exploring CLimAte Impacts on Management (EXCLAIM) decision support system (DSS), which simulates flow-driven habitat condition for 16 vegetation species, 13 waterbird species and 4 fish groups in the Macquarie catchment, Australia. The EXCLAIM DSS estimates impacts to habitat condition, considering scenarios of climate change and water management. The model framework underlying the DSS is a probabilistic Bayesian network, and this approach was chosen to explicitly represent uncertainties in climate change scenarios and predicted ecological outcomes. The results suggest that the scenario with no climate change and no water resource development (i.e. flow condition without dams, weirs or water license entitlements, often regarded as a surrogate for 'natural' flow) consistently has the most beneficial outcomes for vegetation, waterbird and native fish. The 2030 dry climate change scenario delivers the poorest ecological outcomes overall, whereas the 2030 wet climate change scenario has beneficial outcomes for waterbird breeding, but delivers poor outcomes for river red gum and black box woodlands, and fish that prefer river channels as habitats. A formal evaluation of the waterbird breeding model showed that higher numbers of observed nest counts are typically associated with higher modelled average breeding habitat conditions. The EXCLAIM DSS provides a generic framework to link hydrology and ecological habitats for a large number of species, based on best available knowledge of their flood requirements. It is a starting point towards developing an integrated tool for assessing climate change impacts on wetland ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Once-daily atenolol in hypertensive Zimbabwean blacks. A double-blind trial using two different doses.

PubMed

Abson, C P; Levy, L M; Eyherabide, G

1981-07-11

A double-blind within-patient study was carried out on Zimbabwean Blacks to investigate the effect of once-daily atenolol on hypertension in doses of 100 and 200 mg/d. Atenolol 200 mg produced significant changes in diastolic pressure readings taken in the supine and standing positions and after exercise; with atenolol 100 mg modest but non-significant changes occurred. These findings are less impressive than those previously reported in White subjects. We conclude that beta-adrenoceptor blocking agents should not be used as drugs of first choice for hypertension in our Black population.

Race, Ethnicity, and Self-Reported Hypertension: Analysis of Data From the National Health Interview Survey, 1997–2005

PubMed Central

2009-01-01

Objective. I estimated the association between race and self-reported hypertension among Hispanics and non-Hispanics and determined whether this association was stronger among non-Hispanics. Methods. With data from the 1997–2005 National Health Interview Survey, I used logistic regression to estimate the strength of the association between race/ethnicity and self-reported hypertension among US adults. Results. The overall prevalence of self-reported hypertension was 24.5%, with lower prevalence among Hispanics (16.7%) than among non-Hispanics (25.2%; P < .01). Blacks, regardless of ethnicity, had the highest prevalence. Compared with non-Hispanic Whites, non-Hispanic Blacks had 48% (odds ratio [OR] = 1.48; 95% confidence interval [CI] = 1.41, 1.55) greater odds of reporting hypertension; Hispanic Whites had 23% (OR = 0.81; 95% CI = 0.76, 0.88) lower odds. There was no difference in the strength of the association between race and self-reported hypertension observed among non-Hispanics (OR for Blacks = 1.47) and among Hispanics (OR for Blacks = 1.20; for interaction, P = 0.43). Conclusions. The previously reported hypertension advantage of Hispanics holds for Hispanic Whites only. As Hispanics continue their rapid growth in the United States, race may have important implications on their disease burden, because most US health disparities are driven by race and its socially patterned experiences. PMID:19059869

Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling.

PubMed

Sawaya, Michael A; Stetz, Jeffrey B; Clevenger, Anthony P; Gibeau, Michael L; Kalinowski, Steven T

2012-01-01

We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos) and black bear (U. americanus) populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears (N= 73.5, 95% CI = 64-94 in 2006; N= 50.4, 95% CI = 49-59 in 2008) and black bears (N= 62.6, 95% CI = 51-89 in 2006; N= 81.8, 95% CI = 72-102 in 2008) in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males (λ= 0.93, 95% CI = 0.74-1.17) and females (λ= 0.90, 95% CI = 0.67-1.20) using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains.

Estimating Grizzly and Black Bear Population Abundance and Trend in Banff National Park Using Noninvasive Genetic Sampling

PubMed Central

Sawaya, Michael A.; Stetz, Jeffrey B.; Clevenger, Anthony P.; Gibeau, Michael L.; Kalinowski, Steven T.

2012-01-01

We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos) and black bear (U. americanus) populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears ( = 73.5, 95% CI = 64–94 in 2006;  = 50.4, 95% CI = 49–59 in 2008) and black bears ( = 62.6, 95% CI = 51–89 in 2006;  = 81.8, 95% CI = 72–102 in 2008) in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males ( = 0.93, 95% CI = 0.74–1.17) and females ( = 0.90, 95% CI = 0.67–1.20) using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains. PMID:22567089

Eikonal instability of Gauss-Bonnet-(anti-)-de Sitter black holes

NASA Astrophysics Data System (ADS)

Konoplya, R. A.; Zhidenko, A.

2017-05-01

Here we have shown that asymptotically anti-de Sitter (AdS) black holes in the Einstein-Gauss-Bonnet (GB) theory are unstable under linear perturbations of space-time in some region of parameters. This (eikonal) instability develops at high multipole numbers. We found the exact parametric regions of the eikonal instability and extended this consideration to asymptotically flat and de Sitter cases. The approach to the threshold of instability is driven by purely imaginary quasinormal modes, which are similar to those found recently in Grozdanov, Kaplis, and Starinets, [J. High Energy Phys. 07 (2016) 151, 10.1007/JHEP07(2016)151] for the higher curvature corrected black hole with the planar horizon. The found instability may indicate limits of holographic applicability of the GB-AdS backgrounds. Recently, through the analysis of critical behavior in AdS space-time in the presence of the Gauss-Bonnet term, it was shown [Deppe et al, Phys. Rev. Lett. 114, 071102 (2015), 10.1103/PhysRevLett.114.071102], that, if the total energy content of the AdS space-time is small, then no black holes can be formed with mass less than some critical value. A similar mass gap was also found when considering collapse of mass shells in asymptotically flat Gauss-Bonnet theories [Frolov, Phys. Rev. Lett. 115, 051102 (2015), 10.1103/PhysRevLett.115.051102]. The found instability of all sufficiently small Einstein-Gauss-Bonnet-AdS, dS and asymptotically flat black holes may explain the existing mass gaps in their formation.

Closing the Gap: Forty Years of Economic Progress for Blacks.

ERIC Educational Resources Information Center

Smith, James P.; Welch, Finis R.

This report presents the findings on the long-term economic progress of American blacks. The report consists of seven sections. The first is a general introduction. Section 2 describes major changes in the racial wage gap for males from 1940 to 1980 and identifies the distribution of wage gains among important subgroups in the black population.…

The Causes of the Worsening Employment Situation of Black Youth.

ERIC Educational Resources Information Center

Osterman, Paul

A study was conducted to examine why black youth unemployment has increased and participation rates decreased. The study was conducted in three parts. The first employs 1960 and 1970 census data to examine the impact of local labor market structure and changes in the structure upon the employment growth of black and white youth. The second part…

The Changing Image of the Black Family on Television.

ERIC Educational Resources Information Center

Cummings, Melbourne S.

This discussion of the roles portrayed by blacks in media begins by describing stereotyping in pre-television film and radio, and examining television shows from the 1950s until the early 1980s which included black characters to show that this stereotyping has continued until very recently. The shows covered in this context include "Beulah,""Make…

Proximate Nutritional Evaluation of Gamma Irradiated Black Rice (Oryza sativa L. cv. Cempo ireng)

NASA Astrophysics Data System (ADS)

Riyatun; Suharyana; Ramelan, A. H.; Sutarno; Saputra, O. A.; Suryanti, V.

2018-03-01

Black rice is a type of pigmented rice with black bran covering the endosperm of the rice kernel. The main objective of the present study was to provide details information on the proximate composition of third generation of gamma irradiated black rice (Oryza sativa L. cv. Cempo ireng). In respect to the control, generally speaking, there were no significant changes of moisture, lipids, proteins, carbohydrates and fibers contents have been observed for the both gamma irradiated black rice. However, the 200-BR has slightly better nutritional value than that of 300-BR and the control. The mineral contents of 200-BR increased significantly of about 35% than the non-gamma irradiated black rice.

Poor representation of Blacks, Latinos, and Native Americans in medicine.

PubMed

Rodriguez, José E; Campbell, Kendall M; Adelson, Wendi J

2015-04-01

In this article, the authors discuss how various systems in medicine are limiting representation of blacks, Latinos, and Native Americans. Flat and decreasing percentages of Underrepresented Minorities in Medicine (URMM), especially in the black and Native American populations, is concerning for family medicine since members from URMM groups care for minority and underserved populations in greater numbers. Underrepresentation is not only noted in the medical community but also in our medical schools when it comes to numbers of URMM faculty. The changing definition of "disadvantaged" in medical school admissions has also played a part in limiting URMM representation. In addition, the Medical College Admissions Test (MCAT) excludes black, Latino, and Native American students in greater numbers. The authors support these arguments with evidence from the medical literature. Although unintentional, these systems effectively limit representation of blacks, Latinos, and Native Americans in medicine. Effective changes are suggested and can be implemented to ensure that URMM individuals have equal representation in careers in medicine.

Dual band sensitivity enhancements of a VO(x) microbolometer array using a patterned gold black absorber.

PubMed

Smith, Evan M; Panjwani, Deep; Ginn, James; Warren, Andrew P; Long, Christopher; Figuieredo, Pedro; Smith, Christian; Nath, Janardan; Perlstein, Joshua; Walter, Nick; Hirschmugl, Carol; Peale, Robert E; Shelton, David

2016-03-10

Infrared-absorbing gold black has been selectively patterned onto the active surfaces of a vanadium-oxide-based infrared bolometer array. Patterning by metal lift-off relies on protection of the fragile gold black with an evaporated oxide, which preserves much of gold black's high absorptance. This patterned gold black also survives the dry-etch removal of the sacrificial polyimide used to fabricate the air-bridge bolometers. For our fabricated devices, infrared responsivity is improved 22% in the long-wave IR and 70% in the mid-wave IR by the gold black coating, with no significant change in detector noise, using a 300°C blackbody and 80 Hz chopping rate. The increase in the time constant caused by the additional mass of gold black is ∼15%.

Global Air Quality and Climate

NASA Technical Reports Server (NTRS)

Fiore, Arlene M.; Naik, Vaishali; Steiner, Allison; Unger, Nadine; Bergmann, Dan; Prather, Michael; Righi, Mattia; Rumbold, Steven T.; Shindell, Drew T.; Skeie, Ragnhild B.;

Improving heart health among Black/African American women using civic engagement: a pilot study.

PubMed

Brown, Alison G M; Hudson, Linda B; Chui, Kenneth; Metayer, Nesly; Lebron-Torres, Namibia; Seguin, Rebecca A; Folta, Sara C

2017-01-24

Despite increased risk for cardiovascular disease (CVD) and related conditions, evaluations of health interventions indicate that Black/African American women are less likely to benefit than their white counterparts and are not as likely to engage in behaviors that reduce CVD risk. The purpose of this study was to test the feasibility and effectiveness of civic engagement as an intervention strategy to address heart health in Black/African American women. Using a quasi-experimental pre-post study design, civic engagement was tested by convening a convenience sample of self-identified Black/African American women, ages 30-70 years, English-speaking, and BMI ≥25.0 (n = 28) into "Change Clubs" in four churches. Feasibility was examined through adherence, satisfaction, retention, and ability of Change Clubs to meet at least 50% of self-identified action steps for community change. Effectiveness data included: dietary intake, measures of physical activity, cardiorespiratory fitness, blood pressure, and anthropometrics. Psychosocial factors hypothesized to serve as the mechanisms by which civic engagement enacts behavior change were also assessed. At baseline, the study sample (n = 28) had a mean age of 50.5 y; 53.6% had an associate degree or higher; 60.7% had an income of $35,000 or higher; and 57.4% were employed full time. At the conclusion of the study, all participants were satisfied with the progress of their Change Club and with the overall experience and Change Clubs met their self-identified action steps for community change. The intervention had a significant effect on finish time on the cardiorespiratory fitness test (p < 0.001) and systolic blood pressure (p < 0.001). Study results suggest feasibility and evidence of preliminary effectiveness of using a civic engagement approach to address behavior change in a way that is appealing and acceptable to Black/African American women. NCT02173366.

Changes in waist circumference and body mass index in the US CARDIA cohort: fixed-effects associations with self-reported experiences of racial/ethnic discrimination.

PubMed

Cunningham, Timothy J; Berkman, Lisa F; Kawachi, Ichiro; Jacobs, David R; Seeman, Teresa E; Kiefe, Catarina I; Gortmaker, Steven L

2013-03-01

Prior studies examining the association between self-reported experiences of racial/ethnic discrimination and obesity have had mixed results and primarily been cross-sectional. This study tests the hypothesis that an increase in self-reported experiences of racial/ethnic discrimination predicts gains in waist circumference and body mass index in Black and White women and men over eight years. In race/ethnicity- and gender-stratified models, this study examined whether change in self-reported experiences of racial/ethnic discrimination predicts changes in waist circumference and body mass index over time using a fixed-effects regression approach in SAS statistical software, providing control for both measured and unmeasured time-invariant covariates. Between 1992-93 and 2000-01, self-reported experiences of racial/ethnic discrimination decreased among 843 Black women (75% to 73%), 601 Black men (80% to 77%), 893 White women (30% to 23%) and 856 White men (28% to 23%). In fixed-effects regression models, controlling for all time-invariant covariates, social desirability bias, and changes in education and parity (women only) over time, an increase in self-reported experiences of racial/ethnic discrimination over time was significantly associated with an increase in waist circumference (β=1.09, 95% CI: 0.00-2.19, p=0.05) and an increase in body mass index (β=0.67, 95% CI: 0.19-1.16, p=0.007) among Black women. No associations were observed among Black men and White women and men. These findings suggest that an increase in self-reported experiences of racial/ethnic discrimination may be associated with increases in waist circumference and body mass index among Black women over time.

Combining Theory-Driven Evaluation and Causal Loop Diagramming for Opening the 'Black Box' of an Intervention in the Health Sector: A Case of Performance-Based Financing in Western Uganda.

PubMed

Renmans, Dimitri; Holvoet, Nathalie; Criel, Bart

2017-09-03

Increased attention on "complexity" in health systems evaluation has resulted in many different methodological responses. Theory-driven evaluations and systems thinking are two such responses that aim for better understanding of the mechanisms underlying given outcomes. Here, we studied the implementation of a performance-based financing intervention by the Belgian Technical Cooperation in Western Uganda to illustrate a methodological strategy of combining these two approaches. We utilized a systems dynamics tool called causal loop diagramming (CLD) to generate hypotheses feeding into a theory-driven evaluation. Semi-structured interviews were conducted with 30 health workers from two districts (Kasese and Kyenjojo) and with 16 key informants. After CLD, we identified three relevant hypotheses: "success to the successful", "growth and underinvestment", and "supervision conundrum". The first hypothesis leads to increasing improvements in performance, as better performance leads to more incentives, which in turn leads to better performance. The latter two hypotheses point to potential bottlenecks. Thus, the proposed methodological strategy was a useful tool for identifying hypotheses that can inform a theory-driven evaluation. The hypotheses are represented in a comprehensible way while highlighting the underlying assumptions, and are more easily falsifiable than hypotheses identified without using CLD.

Modeling of Firn Compaction for Estimating Ice-Sheet Mass Change from Observed Ice-Sheet Elevation Change

NASA Technical Reports Server (NTRS)

Li, Jun; Zwally, H. Jay

2011-01-01

Changes in ice-sheet surface elevation are caused by a combination of ice-dynamic imbalance, ablation, temporal variations in accumulation rate, firn compaction and underlying bedrock motion. Thus, deriving the rate of ice-sheet mass change from measured surface elevation change requires information on the rate of firn compaction and bedrock motion, which do not involve changes in mass, and requires an appropriate firn density to associate with elevation changes induced by recent accumulation rate variability. We use a 25 year record of surface temperature and a parameterization for accumulation change as a function of temperature to drive a firn compaction model. We apply this formulation to ICESat measurements of surface elevation change at three locations on the Greenland ice sheet in order to separate the accumulation-driven changes from the ice-dynamic/ablation-driven changes, and thus to derive the corresponding mass change. Our calculated densities for the accumulation-driven changes range from 410 to 610 kg/cu m, which along with 900 kg/cu m for the dynamic/ablation-driven changes gives average densities ranging from 680 to 790 kg/cu m. We show that using an average (or "effective") density to convert elevation change to mass change is not valid where the accumulation and the dynamic elevation changes are of opposite sign.

Melanoma

MedlinePlus

Melanoma is the most serious type of skin cancer. Often the first sign of melanoma is a change in the size, shape, color, or feel of a mole. Most melanomas have a black or black-blue area. Melanoma ...

A Call for Change: Providing Solutions for Black Male Achievement

ERIC Educational Resources Information Center

Casserly, Michael; Lewis, Sharon; Simon, Candace; Uzzell, Renata; Palacios, Moses

2012-01-01

In October 2010, the Council of the Great City Schools released a major report on the academic status of African American males, "A Call for Change: The Social and Educational Factors Contributing to the Outcomes of Black Males in Urban Schools." The report was the first phase of the Council's efforts to recommit the energies of the nation's urban…

How Changes in Families and Schools Are Related to Trends in Black-White Test Scores

ERIC Educational Resources Information Center

Berends, Mark; Lucas, Samuel R.; Penaloza, Roberto V.

2008-01-01

Through several decades of research, a great deal has been written about trends in black-white test scores and the factors that may explain the gaps in different subject areas. Only a few studies have examined the changing relationships between gaps in students' test scores and family and school measures in nationally representative data over…

Changes in abundance and spatial distribution of geese molting near Teshekpuk Lake, Alaska: Interspecific competition or ecological change?

USGS Publications Warehouse

Flint, Paul L.; Mallek, E.J.; King, R.J.; Schmutz, J.A.; Bollinger, K.S.; Derksen, D.V.

2008-01-01

Goose populations molting in the Teshekpuk Lake Special Area of the National Petroleum Reserve-Alaska have changed in size and distribution over the past 30 years. Black brant (Branta bernicla nigricans) are relatively stable in numbers but are shifting from large, inland lakes to salt marshes. Concurrently, populations of greater white-fronted geese (Anser albifrons frontalis) have increased seven fold. Populations of Canada geese (Branta canadensis and/or B. hutchinsii) are stable with little indication of distributional shifts. The lesser snow goose (Anser caerulescens caerulescens) population is proportionally small, but increasing rapidly. Coastline erosion of the Beaufort Sea has altered tundra habitats by allowing saltwater intrusion, which has resulted in shifts in composition of forage plant species. We propose two alternative hypotheses for the observed shift in black brant distribution. Ecological change may have altered optimal foraging habitats for molting birds, or alternatively, interspecific competition between black brant and greater white-fronted geese may be excluding black brant from preferred habitats. Regardless of the causative mechanism, the observed shifts in species distributions are an important consideration for future resource planning. ?? 2007 Springer-Verlag.

Broad Hβ Emission-line Variability in a Sample of 102 Local Active Galaxies

NASA Astrophysics Data System (ADS)

Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.; Scott, Bryan; Komossa, S.; Malkan, Matthew A.; Lazarova, Mariana S.; Auger, Matthew W.; Treu, Tommaso; Park, Daeseong

2016-04-01

A sample of 102 local (0.02 ≤ z ≤ 0.1) Seyfert galaxies with black hole masses MBH > 107M⊙ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between MBH and host galaxy properties. We study profile changes of the broad Hβ emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad Hβ emission line is of particular interest, not only because it is used to estimate MBH, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (∼66%) of the objects, resulting in a Seyfert-type change for ∼38% of the objects, likely driven by variable accretion and/or obscuration. The broad Hβ line virtually disappears in 3/102 (∼3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of Hβ line variability in a sample of low-redshift Seyfert galaxies.

Promoting change through political consciousness: a South African speech-language pathology response to the World Report on Disability.

PubMed

Kathard, Harsha; Pillay, Mershen

2013-02-01

In the context of the World Report on Disability, Wylie, McAllister, Davidson, and Marshall (2013) question how speech-language pathologists (SLPs) change practices to benefit under-served people with communication disability. This commentary provides a South African response premised on Political Consciousness. In South Africa, a grossly unequal society, the under-served population is not only those with communication disability but also include those who are at a communication disadvantage due to disabling conditions. As a consequence of the combined effects of a severe shortage of SLPs as well as maldistribution in service provision, the under-served are mainly poor Black South Africans who are the majority population. Political Consciousness allows one to examine how selected forces at the macro-level, meso-level, and micro-level may enable or limit services to the under-served majority. At a macro-level, this study appraises policies and actions advancing and impeding service delivery. At the meso-level it is argued that hegemonic professional knowledge is limiting and an equity-driven population-based approach is advocated. At a micro-level, the Relationship of Labouring Affinities is offered as a conceptual tool for critical engagement. In conclusion, it is suggested that the speech-language pathology profession must collectively become political actors at all levels to effect change.

Potential climate impact of black carbon emitted by rockets

NASA Astrophysics Data System (ADS)

Ross, Martin; Mills, Michael; Toohey, Darin

2010-12-01

A new type of hydrocarbon rocket engine is expected to power a fleet of suborbital rockets for commercial and scientific purposes in coming decades. A global climate model predicts that emissions from a fleet of 1000 launches per year of suborbital rockets would create a persistent layer of black carbon particles in the northern stratosphere that could cause potentially significant changes in the global atmospheric circulation and distributions of ozone and temperature. Tropical stratospheric ozone abundances are predicted to change as much as 1%, while polar ozone changes by up to 6%. Polar surface temperatures change as much as one degree K regionally with significant impacts on polar sea ice fractions. After one decade of continuous launches, globally averaged radiative forcing from the black carbon would exceed the forcing from the emitted CO2 by a factor of about 105 and would be comparable to the radiative forcing estimated from current subsonic aviation.

Effects of cosmic acceleration on black hole thermodynamics

NASA Astrophysics Data System (ADS)

Mandal, Abhijit

2016-07-01

Direct local impacts of cosmic acceleration upon a black hole are matters of interest. Babichev et. al. had published before that the Friedmann equations which are prevailing the part of fluid filled up in the universe to lead (or to be very specific, `dominate') the other constituents of universe and are forcing the universe to undergo present-day accelerating phase (or to lead to violate the strong energy condition and latter the week energy condition), will themselves tell that the rate of change of mass of the central black hole due to such exotic fluid's accretion will essentially shrink the mass of the black hole. But this is a global impact indeed. The local changes in the space time geometry next to the black hole can be analysed from a modified metric governing the surrounding space time of a black hole. A charged deSitter black hole solution encircled by quintessence field is chosen for this purpose. Different thermodynamic parameters are analysed for different values of quintessence equation of state parameter, ω_q. Specific jumps in the nature of the thermodynamic space near to the quintessence or phantom barrier are noted and physically interpreted as far as possible. Nature of phase transitions and the situations at which these transitions are taking place are also explored. It is determined that before quintessence starts to work (ω_q=-0.33>-1/3) it was preferable to have a small unstable black hole followed by a large stable one. But in quintessence (-1/3>ω_q>-1), black holes are destined to be unstable large ones pre-quelled by stable/ unstable small/ intermediate mass black holes.

Black Hole Variability in MHD: A Numerical Test of the Propagating Fluctuations Model

NASA Astrophysics Data System (ADS)

Hogg, J. Drew; Reynolds, Christopher S.

2017-08-01

The variability properties of accreting black hole systems offer a crucial probe of the accretion physics providing the angular momentum transport and enabling the mass accretion. A few of the most telling signatures are the characteristic log-normal flux distributions, linear RMS-flux relations, and frequency-dependent time lags between energy bands. These commonly observed properties are often interpreted as evidence of inward propagating mass accretion rate fluctuations where fluctuations in the accretion flow combine multiplicatively. We present recent results from a long, semi-global MHD simulation of a thin (h/r=0.1) accretion disk that naturally reproduces this phenomenology. This bolsters the theoretical underpinnings of the “propagating fluctuations” model and demonstrates the viability of this process manifesting in MHD turbulence driven by the magnetorotational instability. We find that a key ingredient to this model is the modulation of the effective α parameter by the magnetic dynamo.

Graphene/black phosphorus heterostructured photodetector

NASA Astrophysics Data System (ADS)

Xu, Jiao; Song, Young Jae; Park, Jin-Hong; Lee, Sungjoo

2018-06-01

Graphene photodetectors exhibit a low photoresponsivity due to their weak light absorbance. In this study, we fabricated a graphene/black phosphorus (BP) heterostructure, in which the multilayer BP flake with a ∼0.3 eV direct band gap functions as an enhanced light-absorption material. Further, the photoexcited electrons are trapped in the trap states of the BP, which creates a photogating effect and causes holes to flow into the graphene layer driven by the built-in potential between BP and graphene. The photocarrier lifetime is therefore prolonged by trapping, and as a result of the high carrier mobility of graphene, the holes that transfer into the graphene channel can travel through the circuit before they recombine with trapped electrons. These combined effects result in a high photoresponsivity: 55.75 A/W at λ = 655 nm, 1.82 A/W at λ = 785 nm, and 0.66 A/W at λ = 980 nm.

Does Black Socioeconomic Mobility Explain Recent Progress Toward Black-White Residential Integration?

PubMed

Wagmiller, Robert L; Gage-Bouchard, Elizabeth; Karraker, Amelia

2017-08-01

Studies of racial residential segregation have found that black-white segregation in U.S. metropolitan areas has declined slowly but steadily since the early 1970s. As of this writing, black-white residential segregation in the United States is approximately 25 % lower than it was in 1970. To identify the sources of this decline, we used individual-level, geocoded data from the Panel Study of Income Dynamics (PSID) to compare the residential attainment of different cohorts of blacks. We analyzed these data using Blinder-Oaxaca regression decomposition techniques that partition the decline in residential segregation among cohorts into the decline resulting from (1) changes in the social and economic characteristics of blacks and (2) changes in the association between blacks' social and economic characteristics and the level of residential segregation they experience. Our findings show that black cohorts entering adulthood prior to the civil rights movement of the 1960s experienced consistently high levels of residential segregation at middle age, but that cohorts transitioning to adulthood during and after this period of racial progress experienced significantly lower levels of residential segregation. We find that the decline in black-white residential segregation for these later cohorts reflects both their greater social and economic attainment and a strengthening of the association between socioeconomic characteristics and residential segregation. Educational gains for the post-civil rights era cohorts and improved access to integrated neighborhoods for high school graduates and college attendees in these later cohorts were the principal source of improved residential integration over this period.

Fractional noise destroys or induces a stochastic bifurcation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Qigui, E-mail: qgyang@scut.edu.cn; Zeng, Caibin, E-mail: zeng.cb@mail.scut.edu.cn; School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640

2013-12-15

Little seems to be known about the stochastic bifurcation phenomena of non-Markovian systems. Our intention in this paper is to understand such complex dynamics by a simple system, namely, the Black-Scholes model driven by a mixed fractional Brownian motion. The most interesting finding is that the multiplicative fractional noise not only destroys but also induces a stochastic bifurcation under some suitable conditions. So it opens a possible way to explore the theory of stochastic bifurcation in the non-Markovian framework.

Radiatively-driven general relativistic jets

NASA Astrophysics Data System (ADS)

Vyas, Mukesh K.; Chattopadhyay, Indranil

2018-02-01

We use moment formalism of relativistic radiation hydrodynamics to obtain equations of motion of radial jets and solve them using polytropic equation of state of the relativistic gas. We consider curved space-time around black holes and obtain jets with moderately relativistic terminal speeds. In addition, the radiation field from the accretion disc, is able to induce internal shocks in the jet close to the horizon. Under combined effect of thermal as well as radiative driving, terminal speeds up to 0.75 (units of light speed) are obtained.

Moving the Goalposts: Education Policy and 25 Years of the Black/White Achievement Gap

ERIC Educational Resources Information Center

Gillborn, David; Demack, Sean; Rollock, Nicola; Warmington, Paul

2017-01-01

Drawing on a secondary analysis of official statistics, this paper examines the changing scale of the inequality of achievement between White students and their Black British peers who identify their family heritage as Black Caribbean. We examine a 25-year period from the introduction of the General Certificate of Secondary Education (GCSE), in…

Participation in Black Lives Matter and Deferred Action for Childhood Arrivals: Modern Activism among Black and Latino College Students

ERIC Educational Resources Information Center

Hope, Elan C.; Keels, Micere; Durkee, Myles I.

2016-01-01

Political activism is one way racially/ethnically marginalized youth can combat institutional discrimination and seek legislative change toward equality and justice. In the current study, we examine participation in #BlackLivesMatter (BLM) and advocacy for Deferred Action for Childhood Arrivals (DACA) as political activism popular among youth.…

A Maverick in the Field: The Oram Group and Fundraising in the Black College Community during the 1970s

ERIC Educational Resources Information Center

Gasman, Marybeth; Drezner, Noah D.

2009-01-01

The purpose of this article is to provide a better understanding of the history of fundraising in black college communities; to complicate understandings of white involvement in black college fundraising; to understand the role of fundraising, that is, fundraising for social change and social justice, during the period that followed the…

Black, Male and Teaching: Exploring the Experiences, Perspectives and Teaching Practices of Black Male Teachers

ERIC Educational Resources Information Center

Fant, Tyrie Lavyal

2017-01-01

As America's K-12 student population continues to become more diverse, it is important that the ethnic background of the teacher population reflect this change. A crucial aspect of this diversification effort includes black male teachers. The purpose of this study was to explore and examine the experiences and perspectives of African American male…

Vitamin D status of black and white Americans and changes in vitamin D metabolites after varied doses of vitamin D supplementation

USDA-ARS?s Scientific Manuscript database

Background. Controversy exists over the cause of disparate circulating 25-hydroxyvitaminD (25OHD) between black and white Americans. Objective: To determine whether there are differences in total and directly measured free 25OHD between black and white American adults and to assess the degree to w...

Identifying changes in tree form for harvested ponderosa pine in the Black Hills

Treesearch

Michael S. Williams; Raymond L. Czaplewski; Don L. Martinez

1996-01-01

Recent underestimates of total volume for timber sales in the Black Hills National Forest prompted analysis of two felled ponderosa pine (Pinus ponderosa Laws.) data sets that were collected approximately 10 years apart. Though neither data set collected was a representative sample of the Black Hills, both were similar in terms of diameter at breast height and total...

The Vanishing Black American Family or: What's Happening with the Manchild?

ERIC Educational Resources Information Center

Raiford, Gilbert L.

1987-01-01

Analyzes the causes and effects of changes in the family of American Blacks. Identifies persistent, institutional racism as the primary cause for the plight of Black male youths. Classifies the latter into three groups: (1) the small percentage who attain a career; (2) the 51% who steadily seek work and rarely succeed; and (3) the displaced and…

Educational Change in the Black Population of the United States and the South.

ERIC Educational Resources Information Center

Bouvier, Leon F.

The origins of the education of blacks, especially in the South, are traced, in order to comprehend the current educational situation. Two questions are investigated: first, whether the conclusion of the Civil War marks the beginning of a new educational era for the nineteenth century blacks; and second, whether there have in fact been real…

Achromatic-chromatic colorimetric sensors for on-off type detection of analytes.

PubMed

Heo, Jun Hyuk; Cho, Hui Hun; Lee, Jin Woong; Lee, Jung Heon

2014-12-21

We report the development of achromatic colorimetric sensors; sensors changing their colors from achromatic black to other chromatic colors. An achromatic colorimetric sensor was prepared by mixing a general colorimetric indicator, whose color changes between chromatic colors, and a complementary colored dye with no reaction to the targeted analyte. As the color of an achromatic colorimetric sensor changes from black to a chromatic color, the color change could be much easily recognized than general colorimetric sensors with naked eyes. More importantly, the achromatic colorimetric sensors enable on-off type recognition of the presence of analytes, which have not been achieved from most colorimetric sensors. In addition, the color changes from some achromatic colorimetric sensors (achromatic Eriochrome Black T and achromatic Benedict's solution) could be recognized with naked eyes at much lower concentration ranges than normal chromatic colorimetric sensors. These results provide new opportunities in the use of colorimetric sensors for diverse applications, such as harsh industrial, environmental, and biological detection.

An Insight into the Sialome of the Black Fly, Simulium vittatum

PubMed Central

Andersen, John F.; Pham, Van M.; Meng, Zhaojing; Champagne, Donald E.; Ribeiro, José M. C.

2009-01-01

Adaptation to vertebrate blood feeding includes development of a salivary ‘magic potion’ that can disarm host hemostasis and inflammatory reactions. Within the lower Diptera, a vertebrate blood-sucking mode evolved in the Psychodidae (sand flies), Culicidae (mosquitoes), Ceratopogonidae (biting midges), Simuliidae (black flies), and in the frog-feeding Corethrellidae. Sialotranscriptome analyses from several species of mosquitoes and sand flies and from one biting midge indicate divergence in the evolution of the blood-sucking salivary potion, manifested in the finding of many unique proteins within each insect family, and even genus. Gene duplication and divergence events are highly prevalent, possibly driven by vertebrate host immune pressure. Within this framework, we describe the sialome (from Greek sialo, saliva) of the black fly Simulium vittatum and discuss the findings within the context of the protein families found in other blood-sucking Diptera. Sequences and results of Blast searches against several protein family databases are given in Supplemental Tables S1 and S2, which can be obtained from http://exon.niaid.nih.gov/transcriptome/S_vittatum/T1/SV-tb1.zip and http://exon.niaid.nih.gov/transcriptome/S_vittatum/T2/SV-tb2.zip. PMID:19166301

Black Hole Foraging: Feedback Drives Feeding

NASA Astrophysics Data System (ADS)

Dehnen, Walter; King, Andrew

2013-11-01

We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

Black TiO2 synthesized via magnesiothermic reduction for enhanced photocatalytic activity

NASA Astrophysics Data System (ADS)

Wang, Xiangdong; Fu, Rong; Yin, Qianqian; Wu, Han; Guo, Xiaoling; Xu, Ruohan; Zhong, Qianyun

2018-04-01

Utilizing solar energy for hydrogen evolution is a great challenge for its insufficient visible-light power conversion. In this paper, we report a facile magnesiothermic reduction of commercial TiO2 nanoparticles under Ar atmosphere and at 550 °C followed by acid treatment to synthesize reduced black TiO2 powders, which possesses a unique crystalline core-amorphous shell structure composed of disordered surface and oxygen vacancies and shows significantly improved optical absorption in the visible region. The unique core-shell structure and high absorption enable the reduced black TiO2 powders to exhibit enhanced photocatalytic activity, including splitting of water in the presence of Pt as a cocatalyst and degradation of methyl blue (MB) under visible light irradiation. Photocatalytic evaluations indicate that the oxygen vacancies play key roles in the catalytic process. The maximum hydrogen production rates are 16.1 and 163 μmol h-1 g-1 under the full solar wavelength range of light and visible light, respectively. This facile and versatile method could be potentially used for large scale production of colored TiO2 with remarkable enhancement in the visible light absorption and solar-driven hydrogen production.

A Periodically Varying Luminous Quasar at z = 2 from the Pan-STARRS1 Medium Deep Survey: A Candidate Supermassive Black Hole Binary in the Gravitational Wave-Driven Regime

NASA Astrophysics Data System (ADS)

Liu, Tingting; Gezari, Suvi

Supermassive black hole binaries (SMBHBs) should be an inevitable consequence of the hierarchical growth of massive galaxies through mergers and the strongest sirens of gravitational waves (GWs) in the cosmos. Yet, their direct detection has remained elusive due to the compact (sub-parsec) orbital separations of gravitationally bound SMBHBs. Here we exploit a theoretically predicted signature of SMBHBs in the time domain. We have begun a systematic search for SMBHB candidates in the Pan-STARRS1 Medium Deep Survey (MDS) and reported our first significant detection of such a candidate from our pilot study of MD09 in Liu et al. (2015). Our candidate PSO J334.2028+01.4075 has a detected period of 542 days, varying persistently over the available baseline. From its archival spectrum, we estimated the black hole mass of the z = 2.06 quasar to be ~1010 M⊙. The inferred ~7 R s binary separation therefore puts this candidate in the regime of GW-dominated orbital decay, opening up the exciting possibility of finding GW sources detectable by pulsar timing arrays (PTAs) in a wide-field optical synoptic survey.

Relativistic Dynamics and Mass Exchange in Binary Black Hole Mini-disks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowen, Dennis B.; Campanelli, Manuela; Mewes, Vassilios

We present the first exploration of gas dynamics in a relativistic binary black hole (BH) system in which an accretion disk (a “mini-disk”) orbits each BH. We focus on 2D hydrodynamical studies of comparable-mass, non-spinning systems. Relativistic effects alter the dynamics of gas in this environment in several ways. Because the gravitational potential between the two BHs becomes shallower than in the Newtonian regime, the mini-disks stretch toward the L1 point and the amount of gas passing back and forth between the mini disks increases sharply with decreasing binary separation. This “sloshing” is quasi-periodically modulated at 2 and 2.75 timesmore » the binary orbital frequency, corresponding to timescales of hours to days for supermassive binary black holes (SMBBHs). In addition, relativistic effects add an m = 1 component to the tidally driven spiral waves in the disks that are purely m = 2 in Newtonian gravity; this component becomes dominant when the separation is ≲100 gravitational radii. Both the sloshing and the spiral waves have the potential to create distinctive radiation features that may uniquely mark SMBBHs in the relativistic regime.« less

Relativistic Dynamics and Mass Exchange in Binary Black Hole Mini-disks

NASA Astrophysics Data System (ADS)

Bowen, Dennis B.; Campanelli, Manuela; Krolik, Julian H.; Mewes, Vassilios; Noble, Scott C.

2017-03-01

We present the first exploration of gas dynamics in a relativistic binary black hole (BH) system in which an accretion disk (a “mini-disk”) orbits each BH. We focus on 2D hydrodynamical studies of comparable-mass, non-spinning systems. Relativistic effects alter the dynamics of gas in this environment in several ways. Because the gravitational potential between the two BHs becomes shallower than in the Newtonian regime, the mini-disks stretch toward the L1 point and the amount of gas passing back and forth between the mini disks increases sharply with decreasing binary separation. This “sloshing” is quasi-periodically modulated at 2 and 2.75 times the binary orbital frequency, corresponding to timescales of hours to days for supermassive binary black holes (SMBBHs). In addition, relativistic effects add an m = 1 component to the tidally driven spiral waves in the disks that are purely m = 2 in Newtonian gravity; this component becomes dominant when the separation is ≲100 gravitational radii. Both the sloshing and the spiral waves have the potential to create distinctive radiation features that may uniquely mark SMBBHs in the relativistic regime.

Patterns of Caregiving of Cuban, Other Hispanic, Caribbean Black, and White Elders in South Florida

PubMed Central

Buckwalter, Kathleen C.; Newman, Frederick L.; Mauro, Ana C.

2013-01-01

Caregivers in Miami, Florida (185 Cubans, 108 other Hispanics, 229 non-Hispanic Whites, and 73 Caribbean Blacks) were described and compared along demographic and health variables, cultural attitudes, and caregiving behaviors. Participants were recruited at random through Home Health Services (61 %) and convenience sampling in the community (39 %), and interviewed at their home. Standardized instruments and measures constructed for this study were pretested. Multivariate analyses showed that the ethnic groups differed in age, education, income, and number of persons giving care, while caregiver health and patient functioning were similar. Controlling for demographics, differences in cultural variables were small. The sense of obligation, emotional attachment, openness about who should give care, spirituality, use of family help or community services were comparable in all groups. Commitment to caregiving was high, driven mainly by patient needs. Cubans had the greatest family stability, and worked the hardest, with the lowest sense of burden. Caribbean Black caregivers lived in bigger families, were youngest, and their patients had the lowest cognitive status. Burden was felt most by White caregivers who were older than the others. Professionals need to understand complex belief systems and behavior patterns to assist caregivers in mobilizing appropriate resources. PMID:23636833

Refinement in black chrome for use as a solar selective coating

NASA Technical Reports Server (NTRS)

Mcdonald, G. E.

1974-01-01

Black chrome is significant as a solar selective coating because the current extensive use of black chrome in the electroplating industry as a durable decorative finish makes black chrome widely available on a commercial scale and potentially low in cost as a solar selective coating. Black-chrome deposits were modified by underplating with dull nickel or by being plated on rough surfaces. Both of these procedures increased the visible absorptance. There was no change in the infrared reflectance for the dull-nickel - black-chrome combination from that reported for the bright-nickel - black-chrome combination. However, the bright-nickel - black-chrome coating plated on rough surfaces indicated a slight decrease in infrared reflectance. As integrated over the solar spectrum for air mass 2, the reflectance of the dull-nickel - black-chrome coating was 0.077, of the bright-nickel - black-chrome coating plated on a 0.75-micron (30-microinch) surface was 0.070, of the bright-nickel - black-chrome coating plated on a 2.5 micron (100-microinch) surface was 0.064. The corresponding values for the bright-nickel - black-chrome coating on a 0.0125-micron (0.5-microinch) surface, two samples of black nickel, and two samples of Nextrel black paint were 0.132, 0.123, 0.133, and 0.033, respectively.

Impact of the Messinian Salinity Crisis on Black Sea hydrology—Insights from hydrogen isotopes analysis on biomarkers

NASA Astrophysics Data System (ADS)

Vasiliev, Iuliana; Reichart, Gert-Jan; Krijgsman, Wout

2013-01-01

The Messinian Salinity Crisis (5.96-5.33 Ma ago) was a dramatic oceanographic event, when evaporites kilometers thick precipitated in a desiccating Mediterranean basin, trapping more than 5% of the world's oceanic salt. Hydrological changes in the adjacent Black Sea and water exchange with the Mediterranean region are crucial, but poorly understood factors, influencing Messinian evaporite formation. Here, we present compound specific hydrogen isotope (δD) data from Messinian Black Sea sedimentary rocks that show a rapid change to heavy waters at 5.8 Ma, when major glaciations occurred. At the same time, highly depleted δD values of long chain n-alkanes derived from plant waxes indicate that fresh, river transported water originated from colder northern latitudes. The δD values of alkenones, biosynthesized by haptophyte algae, show an unprecedented increase of 60‰ within ˜100 kyr. The corresponding rapid change to +110‰ for δD of the Black Sea waters seem unrealistic, being heavier than anywhere in the present day oceans. Regardless of the applied relation between the δD values of the alkenones and δD of the waters where they were produced, the 60‰ enrichment in the δD values of alkenones indicates strongly enhanced evaporitic conditions. Still, the relative distribution of the alkenones implies in-situ growth and reproduction of haptophyte algae, requiring sustained marine conditions in the Black Sea up to 5.6 Ma. This indicates that Mediterranean-Black Sea connectivity persisted during the first MSC phase when gypsum precipitated in the Mediterranean basin. When the Black Sea became isolated, at the peak of the MSC (˜5.6 Ma), it had a strongly negative hydrological budget and rapidly desiccated due to excess evaporation.

Proteomic Analysis Reveals Coordinated Regulation of Anthocyanin Biosynthesis through Signal Transduction and Sugar Metabolism in Black Rice Leaf

PubMed Central

Chen, Linghua; Huang, Yining; Xu, Ming; Cheng, Zuxin; Zheng, Jingui

2017-01-01

Black rice (Oryza sativa L.) is considered to be a healthy food due to its high content of anthocyanins in the pericarp. The synthetic pathway of anthocyanins in black rice grains has been identified, however, the proteomic profile of leaves during grain development is still unclear. Here, isobaric Tags Relative and Absolute Quantification (iTRAQ) MS/MS was carried out to identify statistically significant changes of leaf proteome in the black rice during grain development. Throughout three sequential developmental stages, a total of 3562 proteins were detected and 24 functional proteins were differentially expressed 3–10 days after flowering (DAF). The detected proteins are known to be involved in various biological processes and most of these proteins were related to gene expression regulatory (33.3%), signal transduction (16.7%) and developmental regulation and hormone-like proteins (12.5%). The coordinated changes were consistent with changes in regulatory proteins playing a leading role in leaves during black rice grain development. This indicated that signal transduction between leaves and grains may have an important role in anthocyanin biosynthesis and accumulation during grain development of black rice. In addition, four identified up-regulated proteins associated with starch metabolism suggested that the remobilization of nutrients for starch synthesis plays a potential role in anthocyanin biosynthesis of grain. The mRNA transcription for eight selected proteins was validated with quantitative real-time PCR. Our results explored the proteomics of the coordination between leaf and grain in anthocyanins biosynthesis of grain, which might be regulated by signal transduction and sugar metabolism in black rice leaf. PMID:29244752

Faint AGN in z ≳ 6 Lyman-break galaxies powered by cold accretion and rapid angular momentum transport

NASA Astrophysics Data System (ADS)

Muñoz, Joseph A.; Furlanetto, Steven

2012-11-01

We develop a radiation pressure-balanced model for the interstellar medium of high-redshift galaxies that describes many facets of galaxy formation at z ≳ 6, including star formation rates and distributions and gas accretion on to central black holes. We first show that the vertical gravitational force in the disc of such a model is dominated by the disc self-gravity supported by the radiation pressure of ionizing starlight on gas. Constraining our model to reproduce the UV luminosity function of Lyman-break galaxies (LBGs), we limit the available parameter space to wind mass-loading factors one to four times the canonical value for momentum-driven winds. We then focus our study by exploring the effects of different angular momentum transport mechanisms in the galactic disc and find that accretion driven by gravitational torques, such as from linear spiral waves or non-linear orbit crossings, can build up black hole masses by z = 6 consistent with the canonical M-σ relation with a duty cycle of unity, while accretion mediated by a local viscosity such as in an α-disc results in negligible black hole (BH) accretion. Both gravitational torque models produce X-ray emission from active galactic nuclei (AGN) in high-redshift LBGs in excess of the estimated contribution from high-mass X-ray binaries. Using a recent analysis of deep Chandra observations by Cowie et al., we can already begin to rule out the most extreme regions of our parameter space: the inflow velocity of gas through the disc must either be less than one per cent of the disc circular velocity or the X-ray luminosity of the AGN must be substantially obscured. Moderately deeper future observations or larger sample sizes will be able to probe the more reasonable range of angular momentum transport models and obscuring geometries.

Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity

USGS Publications Warehouse

Barrett, K.; McGuire, A. David; Hoy, E.E.; Kasischke, E.S.

2011-01-01

Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79 000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large fires during a large fire year (2004) to determine the factors that are most important in estimating severity and to identify areas affected by deep‐burning fires. In addition to standard methods of assessing severity using spectral information, we incorporated information regarding topography, spatial pattern of burning, and instantaneous characteristics such as fire weather and fire radiative power. Ensemble techniques using regression trees as a base learner were able to determine fire severity successfully using spectral data in concert with other relevant geospatial data. This method was successful in estimating average conditions, but it underestimated the range of severity.This new approach was used to identify black spruce stands that experienced intermediate‐ to high‐severity fires in 2004 and are therefore susceptible to a shift in regrowth toward deciduous dominance or mixed dominance. Based on the output of the severity model, we estimate that 39% (∼4000 km2) of all burned black spruce stands in 2004 had <10 cm of residual organic layer and may be susceptible a postfire shift in plant functional type dominance, as well as permafrost loss. If the fraction of area susceptible to deciduous regeneration is constant for large fire years, the effect of such years in the most recent decade has been to reduce black spruce stands by 4.2% and to increase areas dominated or co‐dominated by deciduous forest stands by 20%. Such disturbance‐driven modifications have the potential to affect the carbon cycle and climate system at regional to global scales.

Potential shifts in dominant forest cover in interior Alaska driven by variations in fire severity.

PubMed

Barrett, K; McGuire, A D; Hoy, E E; Kasischke, E S

2011-10-01

Large fire years in which >1% of the landscape burns are becoming more frequent in the Alaskan (USA) interior, with four large fire years in the past 10 years, and 79 000 km2 (17% of the region) burned since 2000. We modeled fire severity conditions for the entire area burned in large fires during a large fire year (2004) to determine the factors that are most important in estimating severity and to identify areas affected by deep-burning fires. In addition to standard methods of assessing severity using spectral information, we incorporated information regarding topography, spatial pattern of burning, and instantaneous characteristics such as fire weather and fire radiative power. Ensemble techniques using regression trees as a base learner were able to determine fire severity successfully using spectral data in concert with other relevant geospatial data. This method was successful in estimating average conditions, but it underestimated the range of severity. This new approach was used to identify black spruce stands that experienced intermediate- to high-severity fires in 2004 and are therefore susceptible to a shift in regrowth toward deciduous dominance or mixed dominance. Based on the output of the severity model, we estimate that 39% (approximately 4000 km2) of all burned black spruce stands in 2004 had <10 cm of residual organic layer and may be susceptible a postfire shift in plant functional type dominance, as well as permafrost loss. If the fraction of area susceptible to deciduous regeneration is constant for large fire years, the effect of such years in the most recent decade has been to reduce black spruce stands by 4.2% and to increase areas dominated or co-dominated by deciduous forest stands by 20%. Such disturbance-driven modifications have the potential to affect the carbon cycle and climate system at regional to global scales.

Inactivation of Escherichia coli O157:H7 and Salmonella Typhimurium in black pepper and red pepper by gamma irradiation.

PubMed

Song, Won-Jae; Sung, Hye-Jung; Kim, Sung-Youn; Kim, Kwang-Pyo; Ryu, Sangryeol; Kang, Dong-Hyun

2014-02-17

This study evaluated the efficacy of gamma irradiation to inactivate foodborne pathogens in black pepper (Piper nigrum) and red pepper (dried Capsicum annuum). Black pepper and red pepper inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were subjected to gamma irradiation in the range of 0, 1, 2, 3 and 5 kGy, and color change was evaluated after treatment. Pathogen populations decreased with increasing treatment doses. A gamma irradiation dose of 5 kGy decreased E. coli O157:H7 and S. Typhimurium populations >4.4 to >5.2 log CFU/g in black pepper without causing color change. Similarly, 5 kGy of gamma irradiation yielded reduction of 3.8 to >5.2 log CFU/g for E. coli O157:H7 and S. Typhimurium in red pepper. During gamma irradiation treatment, L*, a* and b* values of red pepper were not significantly changed except for 297 μm to 420 μm size red pepper treated with 5 kGy of gamma irradiation. Based on the D-value of pathogens in black pepper and red pepper, S. Typhimurium showed more resistant to gamma irradiation than did E. coli O157:H7. These results show that gamma irradiation has potential as a non-thermal process for inactivating foodborne pathogens in spices with minimal color changes. Copyright © 2013 Elsevier B.V. All rights reserved.

How Does the Trajectory of Multimorbidity Vary Across Black, White, and Mexican Americans in Middle and Old Age?

PubMed Central

Liang, Jersey; Bennett, Joan M.; Xu, Xiao; Ye, Wen

2011-01-01

Objectives. This research examines intra- and interpersonal differences in multiple chronic conditions reported by Americans aged 51 and older for a period up to 11 years. It focuses on how changes in multimorbidity vary across White, Black, and Mexican Americans. Methods. Data came from 17,517 respondents of the Health and Retirement Study (1995–2006) with up to 5 repeated observations. Hierarchical linear models were employed to analyze ethnic variations in temporal changes of reported comorbidities. Findings. Middle-aged and older Americans have on average nearly 2 chronic diseases at the baseline, which increased to almost 3 conditions in 11 years. White Americans differ from Black and Mexican Americans in terms of level and rate of change of multimorbidity. Mexican Americans demonstrate lower initial levels and slower accumulation of comorbidities relative to Whites. In contrast, Blacks showed an elevated level of multimorbidity throughout the 11-year period of observation, although their rate of change slowed relative to Whites. Discussion. These results suggest that health differences between Black Americans and other ethnic groups including White and Mexican Americans persist in the trajectory of multimorbidity even when population heterogeneity is adjusted. Further research is needed concerning the impact of health disadvantages and differential mortality that may have occurred before middle age as well as exploring the role of nativity, the nature of self-reported diseases, and heterogeneity underlying the average trajectory of multimorbidity for ethnic elders. PMID:21968384

The generalization of charged AdS black hole specific volume and number density

NASA Astrophysics Data System (ADS)

Wang, Zi-Liang; He, Miao; Fang, Chao; Sun, Dao-Quan; Deng, Jian-Bo

2017-04-01

In this paper, by proposing a generalized specific volume, we restudy the P- V criticality of charged AdS black holes in the extended phase space. The results show that most of the previous conclusions can be generalized without change, but the ratio {\\tilde{ρ }}_c should be 3 {\\tilde{α }}/16 in general case. Further research on the thermodynamical phase transition of black hole leads us to a natural interpretation of our assumption, and more black hole properties can be generalized. Finally, we study the number density for charged AdS black hole in higher dimensions, the results show the necessity of our assumption.

Following in the Wake of Anger: When Not Discriminating Is Discriminating

PubMed Central

Shapiro, Jenessa R.; Ackerman, Joshua M.; Neuberg, Steven L.; Maner, Jon K.; Becker, D. Vaughn; Kenrick, Douglas T.

2009-01-01

Does seeing a scowling face change your impression of the next person you see? Does this depend on the race of the two people? Across four studies, White participants evaluated neutrally expressive White males as less threatening when they followed angry (relative to neutral) White faces; Black males were not judged as less threatening following angry Black faces. This lack of threat-anchored contrast for Black male faces is not attributable to a general tendency for White targets to homogenize Black males—neutral Black targets following smiling Black faces were contrasted away from them and seen as less friendly—and emerged only for perceivers low in motivation to respond without prejudice (i.e., for those relatively comfortable responding prejudicially). This research provides novel evidence for the overperception of threat in Black males. PMID:19622758

Sex differentiation and sex change in the protandrous black porgy, Acanthopagrus schlegeli.

PubMed

Wu, Guan-Chung; Tomy, Sherly; Lee, Mong-Fong; Lee, Yan-Horn; Yueh, Wen-Shiun; Lin, Chien-Ju; Lau, En-Lieng; Chang, Ching-Fong

2010-07-01

Protandrous black porgy fish, Acanthopagrus schlegeli, have a striking life cycle with a male sex differentiation at the juvenile stage and male-to-female sex change at 3 years of age. We had characterized the sex differentiation and sex change in this species by the integrative approaches of histology, endocrine and molecular genetics. The fish differentiated in gonad at the age around 4-months and the gonad further developed with a bisexual gonad for almost for 3 years and sex change at 3 year of age. An antagonistic relationship in the testicular and ovarian tissues was found during the development of the gonadal tissue. Male- (such as sf-1, dmrt1, dax-1 and amh) and female- (such as wnt4, foxl2 and cyp19a1a) promoting genes were associated with testicular and ovarian development, respectively. During gonadal sex differentiation, steroidogenic pathway and estrogen signaling were also highly expressed in the brain. The increased expression of sf-1 and wnt4, cyp19a1a in ovarian tissue and decreased expression of dax-1 in the ovarian tissue may play important roles in sex change from a male-to-female. Endocrine factors such as estradiol and luteinizing hormone may also involve in the natural sex change. Estradiol induced the expression of female-promoting genes and resulted in the precocious sex change in black porgy. Our series of studies shed light on the sex differentiation and sex change in protandrous black porgy and other animals. (c) 2009 Elsevier Inc. All rights reserved.

Changing How High Schools Serve Black and Latino Young Men: A Report on NYC's Expanded Success Initiative. Technical Appendices

ERIC Educational Resources Information Center

Villavincencio, Adriana; Klevan, Sarah; Kang, David

2015-01-01

These appendices describe the matching process used to identify an appropriate set of comparison schools for use in the report evaluating Year 2 of the Expanded Success Initiative, "Changing How High Schools Serve Black and Latino Young Men." As described in Chapter 2 of the report, selecting schools similar to ESI schools to serve as a…

Engaging Year 9 Students in Party Politics: Exploring the Changing Nature of Political Campaigning in Victorian Britain

ERIC Educational Resources Information Center

Black, Sarah

2015-01-01

Sarah Black wanted to remedy Year 9's lack of knowledge about nineteenth-century politics. With just five lessons to work with, she decided to devise a sequence on Gladstone and Disraeli, shaping the sequence with an enquiry question that invited argument about change and continuity. Black analyses the status and function of different layers of…

Changes in Financial Aid and Student Enrollment at Historically Black Colleges and Universities after the Tightening of PLUS Credit Standards. REL 2015-082

ERIC Educational Resources Information Center

Johnson, Matthew; Bruch, Julie; Gill, Brian

2015-01-01

The purpose of this study was to examine the changes in financial aid and student enrollment at historically Black colleges and universities (HBCUs) after the U.S. Department of Education increased the credit history requirements necessary to obtain Parental Loans for Undergraduate Students (PLUS). The study used institution-level data to examine…

Plant compositional change in a colony of black-tailed prairie dogs in South Dakota

Treesearch

Richard P. Cincotta; Daniel W. Uresk; Richard M. Hansen

1989-01-01

Peak season multi-species cover of vegetation and burrow mound density were estimated for 3 years along a transect that ran from the geometric center of a black-tailed prairie dog (Cynomys ludovicianus) colony, to its edge. The forb dominated core of the colony expanded 25 m in radius during the study, while plant composition changed dramatically in...

BLACK PRETERM BIRTH RISK IN NON-BLACK NEIGHBORHOODS: EFFECTS OF HISPANIC, ASIAN, AND NON-HISPANIC WHITE ETHNIC DENSITIES

PubMed Central

Mason, Susan M.; Kaufman, Jay S.; Daniels, Julie L.; Emch, Michael E.; Hogan, Vijaya K.; Savitz, David A.

2013-01-01

Purpose Studies of ethnic density and health in the United States have documented poorer health outcomes in black compared to non-black neighborhoods, but few studies have considered the identities of the non-black populations. Methods New York City birth records from 1995 through 2003 and a spatial measure of ethnic density were used to examine preterm birth risks among non-Hispanic black women associated with non-Hispanic white, Hispanic, Asian, and non-Hispanic black neighborhood densities. Logistic regression models were used to estimate the effect on black preterm birth risks of replacing white neighbors with Hispanic, Asian, and black neighbors. Risk differences were computed for changes from the 10th to the 90th percentiles of ethnic density. Results Increasing Hispanic density was associated with reduced preterm birth risks among non-Hispanic black women, especially if the black women were foreign-born (RD=−19.1 per 1,000 births; 95% CI: −28.6, −9.5). Estimates for increasing Asian density were null. Increasing black density was associated with increasing black preterm birth risk, with a threshold at higher levels of black density. Conclusions The low risks of preterm birth among foreign-born non-Hispanic black women in majority-Hispanic neighborhoods may be related to protective psychosocial or nutritional factors in Hispanic neighborhoods. PMID:21737050

Lectures on Black Hole Quantum Mechanics

NASA Astrophysics Data System (ADS)

Wilczek, Frank

The lectures that follow were originally given in 1992, and written up only slightly later. Since then there have been dramatic developments in the quantum theory of black holes, especially in the context of string theory. None of these are reflected here. The concept of quantum hair, which is discussed at length in the lectures, is certainly of permanent interest, and I continue to believe that in some generalized form it will prove central to the whole question of how information is stored in black holes. The discussion of scattering and emission modes from various classes of black holes could be substantially simplified using modern techniques, and from currently popular perspectives the choice of examples might look eccentric. On the other hand fashions have changed rapidly in the field, and the big questions as stated and addressed here, especially as formulated for "real" black holes (nonextremal, in four-dimensional, asymptotically flat space-time, with supersymmetry broken), remain pertinent even as the tools to address them may evolve. The four lectures I gave at the school were based on two lengthy papers that have now been published, "Black Holes as Elementary Particles," Nuclear Physics B380, 447 (1992) and "Quantum Hair on Black Holes," Nuclear Physics B378, 175 (1992). The unifying theme of this work is to help make plausible the possibility that black holes, although they are certainly unusual and extreme states of matter, may be susceptible to a description using concepts that are not fundamentally different from those we use in describing other sorts of quantum-mechanical matter. In the first two lectures I discussed dilaton black holes. The fact that apparently innocuous changes in the "matter" action can drastically change the properties of a black hole is already very significant: it indicates that the physical properties of small black holes cannot be discussed reliably in the abstract, but must be considered with due regard to the rest of physics. (The macroscopic properties of large black holes, in particular those of astrophysical interest, are presumably well described by the familiar Einstein-Maxwell action which governs the massless fields. Heavy fields will at most provide Yukawa tails to the field surrounding the hole.) I will show how perturbations may be set up and analyzed completely, and why doing this is crucial for understanding the semiclassical physics of the hole including the Hawking radiation quantitatively. It will emerge that there is a class of dilaton black holes which behave as rather straightforward elementary particles. In the other two lectures I discussed the issue of hair on black holes, in particular the existence of hair associated with discrete gauge charges and its physical consequences. This hair is particularly interesting to analyze because it is invisible classically and to all order in ℏ. Its existence shows that black holes can have some "internal" quantum numbers in addition to their traditional classification by mass, charge, and angular momentum. The text that follows, follows the original papers closely.

The Supermassive Black Hole—Galaxy Connection

NASA Astrophysics Data System (ADS)

King, Andrew

2014-09-01

The observed scaling relations imply that supermassive black holes (SMBH) and their host galaxies evolve together. Near-Eddington winds from the SMBH accretion discs explain many aspects of this connection. The wind Eddington factor should be in the range ˜1-30. A factor give black hole winds with velocities v˜0.1 c, observable in X-rays, just as seen in the most extreme ultrafast outflows (UFOs). Higher Eddington factors predict slower and less ionized winds, observable in the UV, as in BAL QSOs. In all cases the wind must shock against the host interstellar gas and it is plausible that these shocks should cool efficiently. There is detailed observational evidence for this in some UFOs. The wind sweeps up the interstellar gas into a thin shell and propels it outwards. For SMBH masses below a certain critical ( M- σ) value, all these outflows eventually stall and fall back, as the Eddington thrust of the wind is too weak to drive the gas to large radii. But once the SMBH mass reaches the critical M- σ value the global character of the outflow changes completely. The wind shock is no longer efficiently cooled, and the resulting thermal expansion drives the interstellar gas far from the black hole, which is unlikely to grow significantly further. Simple estimates of the maximum stellar bulge mass M b allowed by self-limited star formation show that the SMBH mass is typically about 10-3 M b at this point, in line with observation. The expansion-driven outflow reaches speeds v out≃1200 km s-1 and drives rates in cool (molecular) gas, giving a typical outflow mechanical energy L mech≃0.05 L Edd, where L Edd is the Eddington luminosity of the central SMBH. This is again in line with observation. These massive outflows may be what makes galaxies become red and dead, and can have several other potentially observable effects. In particular they have the right properties to enrich the intergalactic gas with metals. Our current picture of SMBH-galaxy coevolution is still incomplete, as there is no predictive theory of how the hole accretes gas from its surroundings. Recent progress in understanding how large-scale discs of gas can partially cancel angular momentum and promote dynamical infall offers a possible way forward.

Methods to Improve Survival and Growth of Planted Alternative Species Seedlings in Black Ash Ecosystems Threatened by Emerald Ash Borer

Treesearch

Nicholas Bolton; Joseph Shannon; Joshua Davis; Matthew Grinsven; Nam Noh; Shon Schooler; Randall Kolka; Thomas Pypker; Joseph Wagenbrenner

2018-01-01

Emerald ash borer (EAB) continues to spread across North America, infesting native ash trees and changing the forested landscape. Black ash wetland forests are severely affected by EAB. As black ash wetland forests provide integral ecosystem services, alternative approaches to maintain forest cover on the landscape are needed. We implemented simulated EAB infestations...

Combined use of mark-recapture and genetic analyses reveals response of a black bear population to changes in food productivity

Treesearch

Barbara S. McCall; Michael S. Mitchell; Michael K. Schwartz; Jim Hayden; Samuel A. Cushman; Pete Zager; Wayne F. Kasworm

2013-01-01

We used mark-recapture analysis to investigate the dynamics of a black bear (Ursus americanus) population in northern Idaho where food availability varies seasonally and annually. We conducted noninvasive genetic sampling (NGS) during 2003-2006 in the Purcell Mountains of Idaho to collect black bear DNA samples for individual identification of bears. We used a...

Changes in the Relative Labor Force Status of Black and White Youths: A Review of the Literature.

ERIC Educational Resources Information Center

Mare, Robert D.; Winship, Christopher

Since World War II, unemployment rates for black youths have risen much more rapidly than for white youths. This report reviews possible causes of the worsening relative employment status of black youths, including market and structural trends in the sizes of labor force entry cohorts, competition in the low-wage labor market from women and…

Phase-dependent climate-predator interactions explain three decades of variation in neonatal caribou survival.

PubMed

Bastille-Rousseau, Guillaume; Schaefer, James A; Lewis, Keith P; Mumma, Matthew A; Ellington, E Hance; Rayl, Nathaniel D; Mahoney, Shane P; Pouliot, Darren; Murray, Dennis L

2016-03-01

Climate can have direct and indirect effects on population dynamics via changes in resource competition or predation risk, but this influence may be modulated by density- or phase-dependent processes. We hypothesized that for ungulates, climatic conditions close to parturition have a greater influence on the predation risk of neonates during population declines, when females are already under nutritional stress triggered by food limitation. We examined the presence of phase-dependent climate-predator (PDCP) interactions on neonatal ungulate survival by comparing spatial and temporal fluctuations in climatic conditions, cause-specific mortality and per capita resource limitation. We determined cause-specific fates of 1384 caribou (Rangifer tarandus) from 10 herds in Newfoundland, spanning more than 30 years during periods of numerical increase and decline, while exposed to predation from black bears (Ursus americanus) and coyotes (Canis latrans). We conducted Cox proportional hazards analysis for competing risks, fit as a function of weather metrics, to assess pre- and post-partum climatic influences on survival on herds in population increase and decline phases. We used cumulative incidence functions to compare temporal changes in risk from predators. Our results support our main hypothesis; when caribou populations increased, weather conditions preceding calving were the main determinants of cause-specific mortality, but when populations declined, weather conditions during calving also influenced predator-driven mortality. Cause-specific analysis showed that weather conditions can differentially affect predation risk between black bears and coyotes with specific variables increasing the risk from one species and decreasing the risk from the other. For caribou, nutritional stress appears to increase predation risk on neonates, an interaction which is exacerbated by susceptibility to climatic events. These findings support the PDCP interactions framework, where maternal body condition influences susceptibility to climate-related events and, subsequently, risk from predation. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Foraging responses of black-legged kittiwakes to prolonged food-shortages around colonies on the Bering Sea shelf.

PubMed

Paredes, Rosana; Orben, Rachael A; Suryan, Robert M; Irons, David B; Roby, Daniel D; Harding, Ann M A; Young, Rebecca C; Benoit-Bird, Kelly; Ladd, Carol; Renner, Heather; Heppell, Scott; Phillips, Richard A; Kitaysky, Alexander

2014-01-01

We hypothesized that changes in southeastern Bering Sea foraging conditions for black-legged kittiwakes (Rissa tridactyla) have caused shifts in habitat use with direct implications for population trends. To test this, we compared at-sea distribution, breeding performance, and nutritional stress of kittiwakes in three years (2008-2010) at two sites in the Pribilof Islands, where the population has either declined (St. Paul) or remained stable (St. George). Foraging conditions were assessed from changes in (1) bird diets, (2) the biomass and distribution of juvenile pollock (Theragra chalcogramma) in 2008 and 2009, and (3) eddy kinetic energy (EKE; considered to be a proxy for oceanic prey availability). In years when biomass of juvenile pollock was low and patchily distributed in shelf regions, kittiwake diets included little or no neritic prey and a much higher occurrence of oceanic prey (e.g. myctophids). Birds from both islands foraged on the nearby shelves, or made substantially longer-distance trips overnight to the basin. Here, feeding was more nocturnal and crepuscular than on the shelf, and often occurred near anticyclonic, or inside cyclonic eddies. As expected from colony location, birds from St. Paul used neritic waters more frequently, whereas birds from St. George typically foraged in oceanic waters. Despite these distinctive foraging patterns, there were no significant differences between colonies in chick feeding rates or fledging success. High EKE in 2010 coincided with a 63% increase in use of the basin by birds from St. Paul compared with 2008 when EKE was low. Nonetheless, adult nutritional stress, which was relatively high across years at both colonies, peaked in birds from St. Paul in 2010. Diminishing food resources in nearby shelf habitats may have contributed to kittiwake population declines at St Paul, possibly driven by increased adult mortality or breeding desertion due to high foraging effort and nutritional stress.

Analysis of high-resolution simulations for the Black Forest region from a point of view of tourism climatology - a comparison between two regional climate models (REMO and CLM)

NASA Astrophysics Data System (ADS)

Endler, Christina; Matzarakis, Andreas

2011-03-01

An analysis of climate simulations from a point of view of tourism climatology based on two regional climate models, namely REMO and CLM, was performed for a regional domain in the southwest of Germany, the Black Forest region, for two time frames, 1971-2000 that represents the twentieth century climate and 2021-2050 that represents the future climate. In that context, the Intergovernmental Panel on Climate Change (IPCC) scenarios A1B and B1 are used. The analysis focuses on human-biometeorological and applied climatologic issues, especially for tourism purposes - that means parameters belonging to thermal (physiologically equivalent temperature, PET), physical (precipitation, snow, wind), and aesthetic (fog, cloud cover) facets of climate in tourism. In general, both models reveal similar trends, but differ in their extent. The trend of thermal comfort is contradicting: it tends to decrease in REMO, while it shows a slight increase in CLM. Moreover, REMO reveals a wider range of future climate trends than CLM, especially for sunshine, dry days, and heat stress. Both models are driven by the same global coupled atmosphere-ocean model ECHAM5/MPI-OM. Because both models are not able to resolve meso- and micro-scale processes such as cloud microphysics, differences between model results and discrepancies in the development of even those parameters (e.g., cloud formation and cover) are due to different model parameterization and formulation. Climatic changes expected by 2050 are small compared to 2100, but may have major impacts on tourism as for example, snow cover and its duration are highly vulnerable to a warmer climate directly affecting tourism in winter. Beyond indirect impacts are of high relevance as they influence tourism as well. Thus, changes in climate, natural environment, demography, tourists' demands, among other things affect economy in general. The analysis of the CLM results and its comparison with the REMO results complete the analysis performed within the project Climate Trends and Sustainable Development of Tourism in Coastal and Low Mountain Range Regions (CAST) funded by the German Federal Ministry of Education and Research (BMBF).

Thermal winds in stellar mass black hole and neutron star binary systems

NASA Astrophysics Data System (ADS)

Done, Chris; Tomaru, Ryota; Takahashi, Tadayuki

2018-01-01

Black hole binaries show equatorial disc winds at high luminosities, which apparently disappear during the spectral transition to the low/hard state. This is also where the radio jet appears, motivating speculation that both wind and jet are driven by different configurations of the same magnetic field. However, these systems must also have thermal winds, as the outer disc is clearly irradiated. We develop a predictive model of the absorption features from thermal winds, based on pioneering work of Begelman, McKee & Shields. We couple this to a realistic model of the irradiating spectrum as a function of luminosity to predict the entire wind evolution during outbursts. We show that the column density of the thermal wind scales roughly with luminosity, and does not shut off at the spectral transition, though its visibility will be affected by the abrupt change in ionizing spectrum. We re-analyse the data from H1743-322, which most constrains the difference in wind across the spectral transition, and show that these are consistent with the thermal wind models. We include simple corrections for radiation pressure, which allows stronger winds to be launched from smaller radii. These winds become optically thick around Eddington, which may even explain the exceptional wind seen in one observation of GRO J1655-40. These data can instead be fit by magnetic wind models, but similar winds are not seen in this or other systems at similar luminosities. Hence, we conclude that the majority (perhaps all) of current data can be explained by thermal or thermal-radiative winds.

Jet Precession Driven by a Supermassive Black Hole Binary System in the BL Lac Object PG 1553+113

NASA Astrophysics Data System (ADS)

Caproni, Anderson; Abraham, Zulema; Motter, Juliana Cristina; Monteiro, Hektor

2017-12-01

The recent discovery of a roughly simultaneous periodic variability in the light curves of the BL Lac object PG 1553+113 at several electromagnetic bands represents the first case of such odd behavior reported in the literature. Motivated by this, we analyzed 15 GHz interferometric maps of the parsec-scale radio jet of PG 1553+113 to verify the presence of a possible counterpart of this periodic variability. We used the Cross-entropy statistical technique to obtain the structural parameters of the Gaussian components present in the radio maps of this source. We kinematically identified seven jet components formed coincidentally with flare-like features seen in the γ-ray light curve. From the derived jet component positions in the sky plane and their kinematics (ejection epochs, proper motions, and sky position angles), we modeled their temporal changes in terms of a relativistic jet that is steadily precessing in time. Our results indicate a precession period in the observer’s reference frame of 2.24 ± 0.03 years, compatible with the periodicity detected in the light curves of PG 1553+113. However, the maxima of the jet Doppler boosting factor are systematically delayed relative to the peaks of the main γ-ray flares. We propose two scenarios that could explain this delay, both based on the existence of a supermassive black hole binary system in PG 1553+113. We estimated the characteristics of this putative binary system that also would be responsible for driving the inferred jet precession.

3M's Dry Silver technology: an ideal media for electronic imaging

NASA Astrophysics Data System (ADS)

Morgan, David A.

1991-08-01

In recent years there has been great interest and growth in the ability to create images electronically. This trend has been driven by the lower cost of computing and storing data, and the speed in which this can be accomplished. The ability to scan, create, and transmit color images is possible even with the enormous amount of data needed to create color images with gray scale and high resolution. In the past, there has not been a great demand for color copiers because few color images were in existence. The above-mentioned trend is changing this, and in addition scanners can quickly translate color graphics into electronic forms at affordable costs. The replacement of black and white televisions and monitors with color was rapid and nearly 100% once the technology was available at a reasonable cost. It is felt by some equipment manufacturers that soft copy will replace hard copy and there will be a diminishing need for imaging media. The author believes, however, that the need for hard copy will continue, and in fact may increase, but with new technology. To create black and white or color hard copy from electronically generated data, some essential characteristics are needed. They are: (1) total dryness, (2) rapid access, (3) gray scale, (4) high resolution, (5) good image quality, and (6) easy to use, low-cost, reliable equipment. Some of the leading technologies for this are electrostatic, thermal dye transfer, ink jet, instant silver photography, and 3M's Dry Silver. This paper gives a general overview of these technologies, but its main emphasis is 3M's Dry Silver approach.

Fentanyl related overdose in Indianapolis: Estimating trends using multilevel Bayesian models.

PubMed

Phalen, Peter; Ray, Bradley; Watson, Dennis P; Huynh, Philip; Greene, Marion S

2018-03-20

The opioid epidemic has been largely attributed to changes in prescribing practices over the past 20 years. Although current overdose trends appear driven by the opioid fentanyl, heroin has remained the focus of overdose fatality assessments. We obtained full toxicology screens on lethal overdose cases in a major US city, allowing more accurate assessment of the time-course of fentanyl-related deaths. We used coroner data from Marion County, Indiana comprising 1583 overdose deaths recorded between January 1, 2010 and April 30, 2017. Bayesian multilevel models were fitted to predict likelihood of lethal fentanyl-related overdose using information about the victim's age, race, sex, zip code, and date of death. Three hundred and seventy-seven (23.8%) overdose deaths contained fentanyl across the seven-year period. Rates rose exponentially over time, beginning well below 15% from 2010 through 2013 before rising to approximately 50% by 2017. At the beginning of the study period, rates of fentanyl overdose were lowest among Black persons but increased more rapidly, eventually surpassing Whites. Currently, White females are at particularly low risk of fentanyl overdose whereas Black females are at high risk. Rates were highest for younger and middle-aged groups. Over time, fentanyl was more likely detected without the presence of other opioids. Fentanyl has increasingly been detected in fatal overdose deaths in Marion County. Policy and program responses must focus on education for those at highest risk of fentanyl exposure and death. These responses should also be tailored to meet the unique needs of high-risk demographics. Copyright © 2018 Elsevier Ltd. All rights reserved.

Entropy in the interior of a higher-dimensional black hole

NASA Astrophysics Data System (ADS)

Yang, Jian-Zhi; Liu, Wen-Biao

2018-07-01

Recently Christodoulou and Rovelli brought out a sensible description for the black hole volume as the largest volume. Later the entropy related to this volume in a 4-dimensional Schwarzschild black hole was investigated, which showed that such entropy is proportional to the surface area of the black hole. We will probe into these issues in the context of higher-dimensional case. It is found that the proportion between this entropy and the Bekenstein-Hawking entropy will go down through dramatic change along with the increase of spacetime dimension.

Gauging climate change effects at local scales: weather-based indices to monitor insect harassment in caribou.

PubMed

Witter, Leslie A; Johnson, Chris J; Croft, Bruno; Gunn, Anne; Poirier, Lisa M

2012-09-01

Climate change is occurring at an accelerated rate in the Arctic. Insect harassment may be an important link between increased summer temperature and reduced body condition in caribou and reindeer (both Rangifer tarandus). To examine the effects of climate change at a scale relevant to Rangifer herds, we developed monitoring indices using weather to predict activity of parasitic insects across the central Arctic. During 2007-2009, we recorded weather conditions and used carbon dioxide baited traps to monitor activity of mosquitoes (Culicidae), black flies (Simuliidae), and oestrid flies (Oestridae) on the post-calving and summer range of the Bathurst barren-ground caribou (Rangifer tarandus groenlandicus) herd in Northwest Territories and Nunavut, Canada. We developed statistical models representing hypotheses about effects of weather, habitat, location, and temporal variables on insect activity. We used multinomial logistic regression to model mosquito and black fly activity, and logistic regression to model oestrid fly presence. We used information theory to select models to predict activity levels of insects. Using historical weather data, we used hindcasting to develop a chronology of insect activity on the Bathurst range from 1957 to 2008. Oestrid presence and mosquito and black fly activity levels were explained by temperature. Wind speed, light intensity, barometric pressure, relative humidity, vegetation, topography, location, time of day, and growing degree-days also affected mosquito and black fly levels. High predictive ability of all models justified the use of weather to index insect activity. Retrospective analyses indicated conditions favoring mosquito activity declined since the late 1950s, while predicted black fly and oestrid activity increased. Our indices can be used as monitoring tools to gauge potential changes in insect harassment due to climate change at scales relevant to caribou herds.

Detecting gas hydrate behavior in crude oil using NMR.

PubMed

Gao, Shuqiang; House, Waylon; Chapman, Walter G

2006-04-06

Because of the associated experimental difficulties, natural gas hydrate behavior in black oil is poorly understood despite its grave importance in deep-water flow assurance. Since the hydrate cannot be visually observed in black oil, traditional methods often rely on gas pressure changes to monitor hydrate formation and dissociation. Because gases have to diffuse through the liquid phase for hydrate behavior to create pressure responses, the complication of gas mass transfer is involved and hydrate behavior is only indirectly observed. This pressure monitoring technique encounters difficulties when the oil phase is too viscous, the amount of water is too small, or the gas phase is absent. In this work we employ proton nuclear magnetic resonance (NMR) spectroscopy to observe directly the liquid-to-solid conversion of the water component in black oil emulsions. The technique relies on two facts. The first, well-known, is that water becomes essentially invisible to liquid state NMR as it becomes immobile, as in hydrate or ice formation. The second, our recent finding, is that in high magnetic fields of sufficient homogeneity, it is possible to distinguish water from black oil spectrally by their chemical shifts. By following changes in the area of the water peak, the process of hydrate conversion can be measured, and, at lower temperatures, the formation of ice. Taking only seconds to accomplish, this measurement is nearly direct in contrast to conventional techniques that measure the pressure changes of the whole system and assume these changes represent formation or dissociation of hydrates - rather than simply changes in solubility. This new technique clearly can provide accurate hydrate thermodynamic data in black oils. Because the technique measures the total mobile water with rapidity, extensions should prove valuable in studying the dynamics of phase transitions in emulsions.

The carbon footprint of traditional woodfuels

NASA Astrophysics Data System (ADS)

Bailis, Robert; Drigo, Rudi; Ghilardi, Adrian; Masera, Omar

2015-03-01

Over half of all wood harvested worldwide is used as fuel, supplying ~9% of global primary energy. By depleting stocks of woody biomass, unsustainable harvesting can contribute to forest degradation, deforestation and climate change. However, past efforts to quantify woodfuel sustainability failed to provide credible results. We present a spatially explicit assessment of pan-tropical woodfuel supply and demand, calculate the degree to which woodfuel demand exceeds regrowth, and estimate woodfuel-related greenhouse-gas emissions for the year 2009. We estimate 27-34% of woodfuel harvested was unsustainable, with large geographic variations. Our estimates are lower than estimates from carbon offset projects, which are probably overstating the climate benefits of improved stoves. Approximately 275 million people live in woodfuel depletion `hotspots’--concentrated in South Asia and East Africa--where most demand is unsustainable. Emissions from woodfuels are 1.0-1.2 Gt CO2e yr-1 (1.9-2.3% of global emissions). Successful deployment and utilization of 100 million improved stoves could reduce this by 11-17%. At US$11 per tCO2e, these reductions would be worth over US$1 billion yr-1 in avoided greenhouse-gas emissions if black carbon were integrated into carbon markets. By identifying potential areas of woodfuel-driven degradation or deforestation, we inform the ongoing discussion about REDD-based approaches to climate change mitigation.

The Ed Tech Journey and a Future Driven by Disruptive Change

ERIC Educational Resources Information Center

Grush, Mary, Ed.

2010-01-01

In this article, the author talks about the education technology journey and a future driven by disruptive change. The author first provides a definition of disruptive change. To understand the potential for disruptive change in higher education--a disruption fueled by technology and related trends--the author begins with a look at the past and…

'A Change of Heart': Racial Politics, Scientific Metaphor and Coverage of 1968 Interracial Heart Transplants in the African American Press.

PubMed

Koretzky, Maya Overby

2017-05-01

This paper explores the African American response to an interracial heart transplant in 1968 through a close reading of the black newspaper press. This methodological approach provides a window into African American perceptions of physiological difference between the races, or lack thereof, as it pertained to both personal identity and race politics. Coverage of the first interracial heart transplant, which occurred in apartheid South Africa, was multifaceted. Newspapers lauded the transplant as evidence of physiological race equality while simultaneously mobilising the language of differing 'black' and 'white' hearts to critique racist politics through the metaphor of a 'change of heart'. While interracial transplant created the opportunity for such political commentary, its material reality-potential exploitation of black bodies for white gain-was increasingly a cause for concern, especially after a contentious heart transplant from a black to a white man in May 1968 in the American South.

Free Will, Black Swans and Addiction.

PubMed

Fenton, Ted; Wiers, Reinout W

2017-01-01

The current dominant perspective on addiction as a brain disease has been challenged recently by Marc Lewis, who argued that the brain-changes related to addiction are similar to everyday changes of the brain. From this alternative perspective, addictions are bad habits that can be broken, provided that people are motivated to change. In that case, autonomous choice or "free will" can overcome bad influences from genes and or environments and brain-changes related to addiction. Even though we concur with Lewis that there are issues with the brain disease perspective, we also argue that pointing to black swans can be important, that is: there can be severe cases where addiction indeed tips over into the category of brain disease, but obviously that does not prove that every case of addiction falls into the disease category, that all swans are black. We argue that, for example, people suffering from Korsakoff's syndrome, can be described as having a brain disease, often caused by alcohol addiction. Moreover, the brain changes occurring with addiction are related to choice-behaviour (and the related notions of willed action), habit formation and insight, hence essential mental abilities to break the addiction. We argue for a more graded perspective, where both black swans (severe brain disease which makes recovery virtually impossible) and white swans (unaffected brain) are rare, and most cases of addiction come as geese in different shades of gray.

Radiatively driven relativistic jets in Schwarzschild space-time

NASA Astrophysics Data System (ADS)

Vyas, Mukesh K.; Chattopadhyay, Indranil

2018-06-01

Context. Aims: We carry out a general relativistic study of radiatively driven conical fluid jets around non-rotating black holes and investigate the effects and significance of radiative acceleration, as well as radiation drag. Methods: We apply relativistic equations of motion in curved space-time around a Schwarzschild black hole for axis-symmetric one-dimensional jet in steady state, plying through the radiation field of the accretion disc. Radiative moments are computed using information of curved space-time. Slopes of physical variables at the sonic points are found using L'Hôpital's rule and employing Runge-Kutta's fourth order method to solve equations of motion. The analysis is carried out using the relativistic equation of state of the jet fluid. Results: The terminal speed of the jet depends on how much thermal energy is converted into jet momentum and how much radiation momentum is deposited onto the jet. Many classes of jet solutions with single sonic points, multiple sonic points, as well as those having radiation driven internal shocks are obtained. Variation of all flow variables along the jet-axis has been studied. Highly energetic electron-proton jets can be accelerated by intense radiation to terminal Lorentz factors γT 3. Moderate terminal speed vT 0.5 is obtained for moderately luminous discs. Lepton dominated jets may achieve γT 10. Conclusions: Thermal driving of the jet itself and radiation driving by accretion disc photons produce a wide-ranging jet solutions starting from moderately strong jets to the relativistic ones. Interplay of intensity, the nature of the radiation field, and the energetics of the jet result in a variety of jet solutions. We show that radiation field is able to induce steady shocks in jets, one of the criteria to explain high-energy power-law emission observed in spectra of some of the astrophysical objects.

Child maltreatment risk as a function of poverty and race/ethnicity in the USA.

PubMed

Kim, Hyunil; Drake, Brett

2018-01-29

Child maltreatment is a pressing social problem in the USA and internationally. There are increasing calls for the use of a public health approach to child maltreatment, but the effective adoption of such an approach requires a sound foundation of epidemiological data. This study estimates for the first time, using national data, total and type-specific official maltreatment risks while simultaneously considering environmental poverty and race/ethnicity. National official maltreatment data (2009-13) were linked to census data. We used additive mixed models to estimate race/ethnicity-specific rates of official maltreatment (total and subtypes) as a function of county-level child poverty rates. The additive model coupled with the multilevel design provided empirically sound estimates while handling both curvilinearity and the nested data structure. With increasing county child poverty rates, total and type-specific official maltreatment rates increased in all race/ethnicity groups. At similar poverty levels, White maltreatment rates trended higher than Blacks and Hispanics showed lower rates, especially where the data were most sufficient. For example, at the 25% poverty level, total maltreatment report rates were 6.91% [95% confidence interval (CI): 6.43%-7.40%] for Whites, 6.30% (5.50%-7.11%) for Blacks and 3.32% (2.88%-3.76%) for Hispanics. We find strong positive associations between official child maltreatment and environmental poverty in all race/ethnicity groups. Our data suggest that Black/White disproportionality in official maltreatment is largely driven by Black/White differences in poverty. Our findings also support the presence of a 'Hispanic paradox' in official maltreatment, where Hispanics have lower risks compared with similarly economically situated Whites and Blacks. © The Author(s) 2018; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Black Feminism: An Integrated Review of Literature.

PubMed

Love, Katie L

2016-01-01

This study presents a systematic literature review exploring the uses and potential benefits of Black Feminism in nursing research. Black Feminism may benefit knowledge development for nursing in a variety of ways, such as illuminating the multifaceted factors of Black women's identities in helping scholars move away from generalization of experiences, to improve understanding of health disparities, and making such changes by broadening the social consciousness of the nurse researchers, who are predominantly White. Discrimination in health disparities may be deconstructed if the focus is placed on asking different research questions and offering different interventions with the social structures that contributes to such actions. When Black Feminism guides the research method (including research questions and analysis), the accuracy of representing the experiences of Black women is increased. In this research, Black Feminism highlights experience, coping mechanisms, spiritual values, a tradition of strength, and a holistic view of identity.

Identification of a characteristic antioxidant, anthrasesamone F, in black sesame seeds and its accumulation at different seed developmental stages.

PubMed

Furumoto, Toshio; Nishimoto, Kiyoshi

2016-01-01

Assay-guided fractionation of the methanol extract from black seeds of sesame (Sesamum indicum L.) led to the isolation of an active compound that had a 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. This antioxidant was confirmed to be anthrasesamone F, an anthraquinone derivative previously isolated from different black sesame seeds and biogenetically related to other anthrasesamones in sesame roots. The radical scavenging assay showed that anthrasesamone F had more potent activity than Trolox. The content of anthrasesamone F in different parts and at different developmental stages of black sesame seeds was investigated to clarify the accumulation pattern of this antioxidant in the black seeds. Anthrasesamone F was localized in the seed coat of black seeds and accumulated after the seed coat color changed to black. The content of anthrasesamone F increased gradually with seed maturation and drastically on air-drying, the final stage in sesame cultivation.

Driven neutron star collapse: Type I critical phenomena and the initial black hole mass distribution

NASA Astrophysics Data System (ADS)

Noble, Scott C.; Choptuik, Matthew W.

2016-01-01

We study the general relativistic collapse of neutron star (NS) models in spherical symmetry. Our initially stable models are driven to collapse by the addition of one of two things: an initially ingoing velocity profile, or a shell of minimally coupled, massless scalar field that falls onto the star. Tolman-Oppenheimer-Volkoff (TOV) solutions with an initially isentropic, gamma-law equation of state serve as our NS models. The initial values of the velocity profile's amplitude and the star's central density span a parameter space which we have surveyed extensively and which we find provides a rich picture of the possible end states of NS collapse. This parameter space survey elucidates the boundary between Type I and Type II critical behavior in perfect fluids which coincides, on the subcritical side, with the boundary between dispersed and bound end states. For our particular model, initial velocity amplitudes greater than 0.3 c are needed to probe the regime where arbitrarily small black holes can form. In addition, we investigate Type I behavior in our system by varying the initial amplitude of the initially imploding scalar field. In this case we find that the Type I critical solutions resemble TOV solutions on the 1-mode unstable branch of equilibrium solutions, and that the critical solutions' frequencies agree well with the fundamental mode frequencies of the unstable equilibria. Additionally, the critical solution's scaling exponent is shown to be well approximated by a linear function of the initial star's central density.

Alloying-assisted phonon engineering of layered BiInSe3@nickel foam for efficient solar-enabled water evaporation.

PubMed

Yao, J D; Zheng, Z Q; Yang, G W

2017-11-02

The fresh water crisis has emerged as one of the most urgent bottlenecks hindering the rapid development of modern industry and society. Solar energy-driven water evaporation represents a potential green and sustainable solution to address this issue. Herein, for the first time, centimeter-scale BiInSe 3 -coated nickel foam (BiInSe 3 @NF) as an efficient solar-enabled evaporator was successfully achieved and exploited for solar energy-driven water evaporation. Benefitting from multiple scattering-induced light trapping of the rough substrate, strong light-matter interaction and intermediate band (IB)-induced efficient phonon emission of BiInSe 3 , the BiInSe 3 @NF device achieved a high evaporation rate of 0.83 kg m -2 h -1 under 1 sun irradiation, which is 2.5 times that of pure water. These figures-of-merit are superior to recently reported state-of-the-art photothermal conversion materials, such as black titania, plasmonic assembly and carbon black. In addition, superior stability over a period of 60 days was demonstrated. In summary, the current contribution depicts a facile scenario for design, production and application of an economical and efficient solar-enabled BiInSe 3 @NF evaporator. More importantly, the phonon engineering strategy based on alloying induced IB states can be readily applied to other analogous van der Waals materials and a series of superior vdWM alloys toward photothermal applications can be expected in the near future.

Changes in Financial Aid and Student Enrollment at Historically Black Colleges and Universities after the Tightening of PLUS Credit Standards. Stated Briefly. REL 2015-088

ERIC Educational Resources Information Center

Johnson, Matthew; Bruch, Julie; Gill, Brian

2015-01-01

This "Stated Briefly" report is a companion piece that summarizes the results of another report of the same name. The purpose of this study was to examine the changes in financial aid and student enrollment at historically Black colleges and universities (HBCUs) after the U.S. Department of Education increased the credit history…

The origin of Cretaceous black shales: a change in the surface ocean ecosystem and its triggers

PubMed Central

OHKOUCHI, Naohiko; KURODA, Junichiro; TAIRA, Asahiko

2015-01-01

Black shale is dark-colored, organic-rich sediment, and there have been many episodes of black shale deposition over the history of the Earth. Black shales are source rocks for petroleum and natural gas, and thus are both geologically and economically important. Here, we review our recent progress in understanding of the surface ocean ecosystem during periods of carbonaceous sediment deposition, and the factors triggering black shale deposition. The stable nitrogen isotopic composition of geoporphyrins (geological derivatives of chlorophylls) strongly suggests that N2-fixation was a major process for nourishing the photoautotrophs. A symbiotic association between diatoms and cyanobacteria may have been a major primary producer during episodes of black shale deposition. The timing of black shale formation in the Cretaceous is strongly correlated with the emplacement of large igneous provinces such as the Ontong Java Plateau, suggesting that black shale deposition was ultimately induced by massive volcanic events. However, the process that connects these events remains to be solved. PMID:26194853

Black Carbon Emissions and Impacts on the South American Glacial Region

NASA Astrophysics Data System (ADS)

Molina, L. T.; Gallardo, L.; Schmitt, C. G.

2015-12-01

Black carbon is one of the key short-lived climate pollutants, which is a topic of growing interest for near-term mitigation of climate change and air quality improvement. In this presentation we will examine the emissions and impact of black carbon and co-pollutants on the South American glacial region and describe some recent measurements associated with the PISAC (Pollution and its Impacts on the South American Cryosphere) Initiative. The Andes is the longest continental mountain range in the world, extending about 7000 km along western South America through seven countries with complex topography and covering several climate zones, diversity of ecosystems and communities. Air pollution associated with biomass burning and urban emissions affects extensive areas in the region and is a serious public health concern. Scientific evidence indicates that the Andean cryosphere is changing rapidly as snow fields and glaciers generally recede, leading to changes in stream flow and water quality along the Andes. The challenge is to identify the principal causes of the observed changes so that action can be taken to mitigate this negative trend. Despite the paucity of systematic observations along the Andes, a few modeling and observational studies have indicated the presence of black carbon in the high Andes, with potentially significant impact on the Andean cryosphere.

Thin Disks Gone MAD: Magnetically Arrested Accretion in the Thin Regime

NASA Astrophysics Data System (ADS)

Avara, Mark J.; McKinney, Jonathan C.; Reynolds, Christopher S.

2015-01-01

The collection and concentration of surrounding large scale magnetic fields by black hole accretion disks may be required for production of powerful, spin driven jets. So far, accretion disks have not been shown to grow sufficient poloidal flux via the turbulent dynamo alone to produce such persistent jets. Also, there have been conflicting answers as to how, or even if, an accretion disk can collect enough magnetic flux from the ambient environment. Extending prior numerical studies of magnetically arrested disks (MAD) in the thick (angular height, H/R~1) and intermediate (H/R~.2-.6) accretion regimes, we present our latest results from fully general relativistic MHD simulations of the thinnest BH (H/R~.1) accretion disks to date exhibiting the MAD mode of accretion. We explore the significant deviations of this accretion mode from the standard picture of thin, MRI-driven accretion, and demonstrate the accumulation of large-scale magnetic flux.

Conditional expression of constitutively active estrogen receptor {alpha} in chondrocytes impairs longitudinal bone growth in mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko

2012-09-07

Highlights: Black-Right-Pointing-Pointer Conditional transgenic mice expressing constitutively active estrogen receptor {alpha} (caER{alpha}) in chondrocytes were developed. Black-Right-Pointing-Pointer Expression of caER{alpha} in chondrocytes impaired longitudinal bone growth in mice. Black-Right-Pointing-Pointer caER{alpha} affects chondrocyte proliferation and differentiation. Black-Right-Pointing-Pointer This mouse model is useful for understanding the physiological role of ER{alpha}in vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caER{alpha}{sup ColII}, expressing constitutively activemore » mutant estrogen receptor (ER) {alpha} in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caER{alpha}{sup ColII} mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caER{alpha}{sup ColII} mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caER{alpha}{sup ColII} mice. These results suggest that ER{alpha} is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.« less

The Disk Wind in the Rapidly Spinning Stellar-mass Black Hole 4U 1630-472 Observed with NuSTAR

NASA Technical Reports Server (NTRS)

King, Ashley L.; Walton, Dominic J.; Miller, Jon M.; Barret, Didier; Boggs, Steven E.; Christensen, Finn E.; Craig, William W.; Fabian, Andy C.; Furst, Felix; Hailey, Charles J.;

Timing of new black box warnings and withdrawals for prescription medications.

PubMed

Lasser, Karen E; Allen, Paul D; Woolhandler, Steffie J; Himmelstein, David U; Wolfe, Sidney M; Bor, David H

2002-05-01

Recently approved drugs may be more likely to have unrecognized adverse drug reactions (ADRs) than established drugs, but no recent studies have examined how frequently postmarketing surveillance identifies important ADRs. To determine the frequency and timing of discovery of new ADRs described in black box warnings or necessitating withdrawal of the drug from the market. Examination of the Physicians' Desk Reference for all new chemical entities approved by the US Food and Drug Administration between 1975 and 1999, and all drugs withdrawn from the market between 1975 and 2000 (with or without a prior black box warning). Frequency of and time to a new black box warning or drug withdrawal. A total of 548 new chemical entities were approved in 1975-1999; 56 (10.2%) acquired a new black box warning or were withdrawn. Forty-five drugs (8.2%) acquired 1 or more black box warnings and 16 (2.9%) were withdrawn from the market. In Kaplan-Meier analyses, the estimated probability of acquiring a new black box warning or being withdrawn from the market over 25 years was 20%. Eighty-one major changes to drug labeling in the Physicians' Desk Reference occurred including the addition of 1 or more black box warnings per drug, or drug withdrawal. In Kaplan-Meier analyses, half of these changes occurred within 7 years of drug introduction; half of the withdrawals occurred within 2 years. Serious ADRs commonly emerge after Food and Drug Administration approval. The safety of new agents cannot be known with certainty until a drug has been on the market for many years.

Environmental influences on small eating behavior change to promote weight loss among Black and Hispanic populations.

PubMed

Eldridge, Johanna D; Devine, Carol M; Wethington, Elaine; Aceves, Luz; Phillips-Caesar, Erica; Wansink, Brian; Charlson, Mary E

2016-01-01

Small eating behavior changes are proposed as more feasible to achieve and maintain than larger changes used in traditional behavioral weight loss studies. However, it is unclear whether overweight Black and Hispanic adults in a low-income urban setting experience small changes as feasible and what might influence feasibility. Participants' experiences in a 12-week pilot weight loss intervention were explored qualitatively to determine the feasibility of making small eating behavior changes in this population. After the intervention (69% retention), semi-structured interviews with 46 men and women (mean age 51, 50% Non-Hispanic Black, 43% Hispanic) revealed that making small eating changes was a process shaped by participants' intrapersonal and interpersonal eating environments. Participants responded to intrapersonal and interpersonal eating environmental challenges by adapting small change strategies, navigating eating environments, and negotiating household eating practices. Findings highlight how even small eating behavior changes called for adaptation, navigation, and negotiation of complex eating environments in daily life. These findings were used to improve the trial that followed and underline the importance of feasibility studies to inform community trials. Findings also add to understanding of contextual challenges and the skills needed to implement small changes in a low income, ethnic minority population. Copyright © 2015. Published by Elsevier Ltd.

Environmental influences on small eating behavior change to promote weight loss among Black and Hispanic populations

PubMed Central

Eldridge, Johanna D.; Devine, Carol M.; Wethington, Elaine; Aceves, Luz; Phillips-Caesar, Erica; Wansink, Brian; Charlson, Mary E.

2015-01-01

Small eating behavior changes are proposed as more feasible to achieve and maintain than larger changes used in traditional behavioral weight loss studies. However, it is unclear whether overweight Black and Hispanic adults in a low-income urban setting experience small changes as feasible and what might influence feasibility. Participants' experiences in a 12-week pilot weight loss intervention were explored qualitatively to determine the feasibility of making small eating behavior changes in this population. After the intervention (69% retention), semi-structured interviews with 46 men and women (mean age 51, 50% Non-Hispanic Black, 43% Hispanic) revealed that making small eating changes was a process shaped by participants' intrapersonal and interpersonal eating environments. Participants responded to intrapersonal and interpersonal eating environmental challenges by adapting small change strategies, navigating eating environments, and negotiating household eating practices. Findings highlight how even small eating behavior changes called for adaptation, navigation, and negotiation of complex eating environments in daily life. These findings were used to improve the trial that followed and underline the importance of feasibility studies to inform community trials. Findings also add to understanding of contextual challenges and the skills needed to implement small changes in a low income, ethnic minority population. PMID:26368577

Explaining Changes in the Patterns of Black Suicide in the United States from 1981 to 2002: An Age, Cohort, and Period Analysis

ERIC Educational Resources Information Center

Joe, Sean

2006-01-01

To explore the different trends of suicide incidence among Blacks and possible contributing factors, the current study compared national epidemiologic data of suicide in the United States from 1981 to 2002. For the first time, period and birth-cohort effects on the incidence trends of Black suicide were evaluated using an age-period-cohort…

Drought tolerance, xylem sap abscisic acid and stomatal conductance during soil drying: a comparison of young plants of four temperate deciduous angiosperms.

PubMed

Loewenstein, Nancy J.; Pallardy, Stephen G.

1998-07-01

Patterns of water relations, xylem sap abscisic acid (ABA) concentration ([ABA]) and stomatal aperture were compared in drought-sensitive black walnut (Juglans nigra L.) and black willow (Salix nigra Marsh.), less drought-sensitive sugar maple (Acer saccharum Marsh.) and drought-tolerant white oak (Quercus alba L.). Strong correlations among reduction in predawn water potential, increase in xylem sap [ABA] and stomatal closure were observed in all species. Stomatal response was more highly correlated with xylem [ABA] than with ABA flux. Xylem sap pH and ion concentrations appeared not to play a major role in the stomatal response of these species. Stomata were more sensitive to relative changes in [ABA] in drought-sensitive black walnut and black willow than in sugar maple and white oak. In the early stages of drought, increased [ABA] in the xylem sap of black walnut and black willow was probably of root origin and provided a signal to the shoot of the water status of the roots. In sugar maple and white oak, leaf water potential declined with the onset of stomatal closure, so that stomatal closure also may have occurred in response to the change in leaf water potential.

Effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate

USGS Publications Warehouse

Jafarov, Elchin E.; Romanovsky, Vladimir E.; Genet, Helene; McGuire, Anthony David; Marchenko, Sergey S.

2013-01-01

Fire is an important factor controlling the composition and thickness of the organic layer in the black spruce forest ecosystems of interior Alaska. Fire that burns the organic layer can trigger dramatic changes in the underlying permafrost, leading to accelerated ground thawing within a relatively short time. In this study, we addressed the following questions. (1) Which factors determine post-fire ground temperature dynamics in lowland and upland black spruce forests? (2) What levels of burn severity will cause irreversible permafrost degradation in these ecosystems? We evaluated these questions in a transient modeling–sensitivity analysis framework to assess the sensitivity of permafrost to climate, burn severity, soil organic layer thickness, and soil moisture content in lowland (with thick organic layers, ~80 cm) and upland (with thin organic layers, ~30 cm) black spruce ecosystems. The results indicate that climate warming accompanied by fire disturbance could significantly accelerate permafrost degradation. In upland black spruce forest, permafrost could completely degrade in an 18 m soil column within 120 years of a severe fire in an unchanging climate. In contrast, in a lowland black spruce forest, permafrost is more resilient to disturbance and can persist under a combination of moderate burn severity and climate warming.

Analysis of internal structure changes in black human hair keratin fibers with aging using Raman spectroscopy.

PubMed

Kuzuhara, Akio; Fujiwara, Nobuki; Hori, Teruo

To investigate the internal structure changes in virgin black human hair keratin fibers due to aging, the structure of cross-sections at various depths of virgin black human hair (sections of new growth hair: 2 mm from the scalp) from a group of eight Japanese females in their twenties and another group of eight Japanese females in their fifties were analyzed using Raman spectroscopy. For the first time, we have succeeded in recording the Raman spectra of virgin black human hair, which had been impossible due to high melanin granule content. The key points of this method are to cross-section hair samples to a thickness of 1.50-microm, to select points at various depths of the cortex with the fewest possible melanin granules, and to optimize laser power, cross slit width as well as total acquisition time. The reproducibility of the Raman bands, namely the alpha-helix (alpha) content, the beta-sheet and/or random coil (beta/R) content, the disulfide (--SS--) content, and random coil content of two adjoining cross-sections of a single hair keratin fiber was clearly good. The --SS-- content of virgin black human hair from the Japanese females in their fifties for the cortex region decreased compared with that of the Japanese females in their twenties. On the other hand, the beta/R and alpha contents of the cortex region did not change.

The contribution of preterm birth to the Black-White infant mortality gap, 1990 and 2000.

PubMed

Schempf, Ashley H; Branum, Amy M; Lukacs, Susan L; Schoendorf, Kenneth C

2007-07-01

We evaluated whether the decline of the racial disparity in preterm birth during the last decade was commensurate with a decline in the contribution of preterm birth to the infant mortality gap. We used linked files of 1990 and 2000 data on US infant births and deaths to partition the gap between Black and White infant mortality rates into differences in the (1) distribution of gestational age and (2) gestational age-specific mortality rates. Between 1990 and 2000, the Black-White infant mortality rate ratio did not change significantly (2.3 vs 2.4). Excess deaths among preterm Black infants accounted for nearly 80% of the Black-White infant mortality gap in both 1990 and 2000. The narrowing racial disparity in the preterm birth rate was counterbalanced by greater mortality reductions in White than in Black preterm infants. Extremely preterm birth (<28 weeks) was 4 times higher in Black infants and accounted for more than half of the infant mortality gap. Substantial reductions in the Black-White infant mortality gap will require improved prevention of extremely preterm birth among Black infants.

REVIEWS OF TOPICAL PROBLEMS: "Magnetized" black holes

NASA Astrophysics Data System (ADS)

Aliev, A. N.; Gal'tsov, D. V.

1989-01-01

Physical aspects of the theory of black holes in an external electromagnetic field are reviewed. The "magnetized" black hole model is currently widely discussed in astrophysics because it provides a basis for the explanation of the high energy activity of galactic cores and quasars. The particular feature of this model is that it predicts unusual "gravimagnetic" phenomena that arise as a result of a natural combination of effects in electrodynamics and gravitation, namely, the appearance of an inductive potential difference during the rotation of a black hole in a magnetic field, the drift of a black hole in an external electromagnetic field, the change in the chemical potential of the event horizon, the creation of an effective ergosphere of a black hole in a magnetic field, and so on. Questions relating to the description of electromagnetic fields in Kerr space-time are examined, including their influence on the space-time metric, the interaction between a rotating charged black hole and an external electromagnetic field, the motion of charged particles near "magnetized" black holes, including their spontaneous and stimulated emission, and the influence of magnetic fields on quantum-mechanical processes in black holes.

Trajectories of late-life change in God-mediated control.

PubMed

Hayward, R David; Krause, Neal

2013-01-01

To track within-individual change during late life in the sense of personal control and God-mediated control (the belief that one can work collaboratively with God to achieve one's goals and exercise control over life events) and to evaluate the hypothesis that this element of religion is related to declining personal control. A longitudinal survey representative of older White and Black adults in the United States tracked changes in personal and God-mediated control in four waves over the course of 7 years. Growth curve analysis found that the pattern of change differed by race. White adults had less sense of God-mediated control at younger ages, which increased among those who were highly religious but decreased among those who were less religious. Black adults had higher God-mediated control, which increased over time among those with low personal control. These results indicate that God-mediated control generally increases during older adulthood, but that its relationships with personal control and religious commitment are complex and differ between Black and White adults.

Determinants of change in body weight and body fat distribution over 5.5 years in a sample of free-living black South African women.

PubMed

Chantler, Sarah; Dickie, Kasha; Micklesfield, Lisa K; Goedecke, Julia H

To identify socio-demographic and lifestyle determinants of weight gain in a sample of premenopasual black South African (SA) women. Changes in body composition (dual-energy X-ray absorptiometry, computerised tomography), socio-economic status (SES) and behavioural/lifestyle factors were measured in 64 black SA women at baseline (27 ± 8 years) and after 5.5 years. A lower body mass index (BMI) and nulliparity, together with access to sanitation, were significant determinants of weight gain and change in body fat distribution over 5.5 years. In addition, younger women increased their body weight more than their older counterparts, but this association was not independent of other determinants. Further research is required to examine the effect of changing SES, as well as the full impact of childbearing on weight gain over time in younger women with lower BMIs. This information will suggest areas for possible intervention to prevent long-term weight gain in these women.

Behavioral Treatment for Weight Gain Prevention Among Black Women in Primary Care Practice

PubMed Central

Bennett, Gary G.; Foley, Perry; Levine, Erica; Whiteley, Jessica; Askew, Sandy; Steinberg, Dori M.; Batch, Bryan; Greaney, Mary L.; Miranda, Heather; Wroth, Thomas H.; Holder, Marni Gwyther; Emmons, Karen M.; Puleo, Elaine

2014-01-01

IMPORTANCE Few weight loss treatments produce clinically meaningful weight loss outcomes among black women, particularly in the primary care setting. New weight management strategies are necessary for this population. Weight gain prevention might be an effective treatment option, with particular benefits for overweight and class 1 obese black women. OBJECTIVE To compare changes in weight and cardiometabolic risk during a 12-month period among black women randomized to a primary care–based behavioral weight gain prevention intervention, relative to usual care. DESIGN, SETTING, AND PARTICIPANTS Two-arm randomized clinical trial (the Shape Program). We recruited patients from a 6-site community health center system. We randomized 194 overweight and class 1 obese (body mass index [calculated as weight in kilograms divided by height in meters squared], 25–34.9) premenopausal black women aged 25 to 44 years. Enrollment began on December 7, 2009; 12- and 18-month assessments were completed in February and October 2, 2012. INTERVENTIONS The medium-intensity intervention included tailored behavior change goals, weekly self-monitoring via interactive voice response, monthly counseling calls, tailored skills training materials, and a gym membership. MAIN OUTCOMES AND MEASURES Twelve-month change in weight and body mass index and maintenance of change at 18 months. RESULTS Participants had a mean age of 35.4 years, a mean weight of 81.1 kg, and a mean body mass index of 30.2 at baseline. Most were socioeconomically disadvantaged (79.7% with educational level less than a college degree; 74.3% reporting annual income <$30 000). The 12-month weight change was larger among intervention participants (mean [SD], −1.0 [0.5] kg), relative to usual care (0.5 [0.5] kg; mean difference, −1.4 kg [95%CI, −2.8 to −0.1 kg]; P = .04). At month 12, 62% of intervention participants were at or below their baseline weights compared with 45% of usual-care participants (P = .03). By 18 months, intervention participants maintained significantly larger changes in weight (mean difference, −1.7 kg; 95% CI, −3.3 to −0.2 kg). CONCLUSIONS AND RELEVANCE A medium-intensity primary care–based behavioral intervention demonstrated efficacy for weight gain prevention among socioeconomically disadvantaged black women. A “maintain, don’t gain” approach might be a useful alternative treatment for reducing obesity-associated disease risk among some premenopausal black women. PMID:23979005

High Energy Interactions in Massive Binaries: An Application to a Most Mysterious Binary

NASA Technical Reports Server (NTRS)

Corcoran, Michael

2013-01-01

Extremely massive stars (50M and above) are exceedingly rare in the local Universe but are believed to have composed the entire first generation of stars, which lived fast, died young and left behind the first generation of black holes and set the stage for the formation of lower mass stars suitable to support life. There are significant uncertainties about how this happened (and how it still happens), mostly due to our poor knowledge of how stars change mass as they evolve. Extremely massive stars give mass back to the ISM via strong radiatively-driven winds and sometimes through sporadic eruptions of the most massive and brightest stars. Such mass loss plays an important role in the chemical and dynamical evolution of the local interstellar medium prior to the supernova explosion. Below we discuss how high energy thermal (and, in some cases, non-thermal) emission, along with modern simulations in 2 and 3 dimensions, can be used to help determine a physically realistic picture of mass loss in a well-studied, mysterious system.