Income Segregation between Schools and School Districts

ERIC Educational Resources Information Center

Owens, Ann; Reardon, Sean F.; Jencks, Christopher

2016-01-01

Although trends in the racial segregation of schools are well documented, less is known about trends in income segregation. We use multiple data sources to document trends in income segregation between schools and school districts. Between-district income segregation of families with children enrolled in public school increased by over 15% from…

49 CFR 176.144 - Segregation of Class 1 (explosive) materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Segregation of Class 1 (explosive) materials. 176... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.144 Segregation of Class... any ferrous metal or aluminum alloy, unless separated by a partition. (e) Segregation on deck: When...

49 CFR 176.144 - Segregation of Class 1 (explosive) materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Segregation of Class 1 (explosive) materials. 176... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.144 Segregation of Class... any ferrous metal or aluminum alloy, unless separated by a partition. (e) Segregation on deck: When...

49 CFR 176.146 - Segregation from non-hazardous materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Segregation from non-hazardous materials. 176.146... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.146 Segregation from non... for “away from” segregation apply. (2) An explosive substance or article which has a secondary...

49 CFR 176.140 - Segregation from other classes of hazardous materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Segregation from other classes of hazardous... CARRIAGE BY VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.140 Segregation from other classes of hazardous materials. (a) Class 1 (explosive) materials must be segregated...

46 CFR 148.120 - Stowage and segregation requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation requirements. 148.120 Section... OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.120 Stowage and segregation requirements. (a) Each material listed in Table 148.10 of this part must be segregated from...

Shaping Income Segregation in Schools: The Role of School Attendance Zone Geography

ERIC Educational Resources Information Center

Saporito, Salvatore

2017-01-01

This study investigates how much the geographic shapes of school attendance zones contributes to their levels of income segregation while holding constant levels of income segregation across residential areas. Income segregation across attendance zones is measured with the rank ordered information theory index. Income segregation across…

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

Kenik, E.A.

X-ray microanalysis in an analytical electron microscope is a proven technique for the measurement of solute segregation in alloys. Solute segregation under equilibrium or nonequilibrium conditions can strongly influence material performance. X-ray microanalysis in an analytical electron microscope provides an alternative technique to measure grain boundary segregation, as well as segregation to other defects not accessible to Auger analysis. The utility of the technique is demonstrated by measurements of equilibrium segregation to boundaries in an antimony containing stainless steel, including the variation of segregation with boundary character and by measurements of nonequilibrium segregation to boundaries and dislocations in an ion-irradiatedmore » stainless steel.« less

Segregation effects during solidification in weightless melts

NASA Technical Reports Server (NTRS)

Li, C.

1973-01-01

Two types of melt segregation effects were studied: (1) evaporative segregation, or segregation due to surface evaporation; and (2) freezing segregation, or segregation due to liquid-solid phase transformation. These segregation effects are closely related. In fact, evaporative segregation always precedes freezing segregation to some degree and must often be studied prior to performing meaningful solidification experiments. This is particularly true since evaporation may cause the melt composition, at least at the critical surface regions or layers to be affected manyfold within seconds so that the surface region or layer melting point and other thermophysical properties, nucleation characteristics, base for undercooling, and critical velocity to avoid constitutional supercooling, may be completely unexpected. An important objective was, therefore, to develop the necessary normal evaporation equations for predicting the compositional changes within specified times at temperature and to correlate these equations with actual experimental data collected from the literature.

Death by Segregation: Does the Dimension of Racial Segregation Matter?

PubMed

Yang, Tse-Chuan; Matthews, Stephen A

2015-01-01

The county-level geographic mortality differentials have persisted in the past four decades in the United States (US). Though several socioeconomic factors (e.g., inequality) partially explain this phenomenon, the role of race/ethnic segregation, in general, and the different dimensions of segregation, more specifically, has been underexplored. Focusing on all-cause age-sex standardized US county-level mortality (2004-2008), this study has two substantive goals: (1) to understand whether segregation is a determinant of mortality and if yes, how the relationship between segregation and mortality varies by racial/ethnic dyads (e.g., white/black), and (2) to explore whether different dimensions of segregation (i.e., evenness, exposure, concentration, centralization, and clustering) are associated with mortality. A third goal is methodological: to assess whether spatial autocorrelation influences our understanding of the associations between the dimensions of segregation and mortality. Race/ethnic segregation was found to contribute to the geographic mortality disparities. Moreover, the relationship with mortality differed by both race/ethnic group and the dimension of segregation. Specifically, white/black segregation is positively related to mortality, whereas the segregation between whites and non-black minorities is negatively associated with mortality. Among the five dimensions of segregation, evenness and exposure are more strongly related to mortality than other dimensions. Spatial filtering approaches also identified six unique spatial patterns that significantly affect the spatial distribution of mortality. These patterns offer possible insights that help identify omitted variables related to the persistent patterning of mortality in the US.

Latino residential segregation and self-rated health among Latinos: Washington State Behavioral Risk Factor Surveillance System, 2012–2014

PubMed Central

Plascak, Jesse J.; Molina, Yamile; Wu-Georges, Samantha; Idris, Ayah; Thompson, Beti

2016-01-01

The relationship between Latino residential segregation and self-rated health (SRH) is unclear, but might be partially affected by social capital. We investigated the association between Latino residential segregation and SRH while also examining the roles of various social capital measures. Washington State Behavioral Risk Factor Surveillance System (2012–2014) and U.S. Census data were linked by zip code and zip code tabulation area. Multilevel logistic regression models were used to estimate odds of good or better SRH by Latino residential segregation, measured by the Gini coefficient, and controlling for sociodemographic, acculturation and social capital measures of neighborhood ties, collective socialization of children, and social control. The Latino residential segregation – SRH relationship was convex, or ‘U’-shaped, such that increases in segregation among Latinos residing in lower segregation areas was associated with lower SRH while increases in segregation among Latinos residing in higher segregation areas was associated with higher SRH. The social capital measures were independently associated with SRH but had little effect on the relationship between Latino residential segregation and SRH. A convex relationship between Latino residential segregation and SRH could explain mixed findings of previous studies. Although important for SRH, social capital measures of neighborhood ties, collective socialization of children, and social control might not account for the relationship between Latino residential segregation and SRH. PMID:27173739

Latino residential segregation and self-rated health among Latinos: Washington State Behavioral Risk Factor Surveillance System, 2012-2014.

PubMed

Plascak, Jesse J; Molina, Yamile; Wu-Georges, Samantha; Idris, Ayah; Thompson, Beti

2016-06-01

The relationship between Latino residential segregation and self-rated health (SRH) is unclear, but might be partially affected by social capital. We investigated the association between Latino residential segregation and SRH while also examining the roles of various social capital measures. Washington State Behavioral Risk Factor Surveillance System (2012-2014) and U.S. Census data were linked by zip code and zip code tabulation area. Multilevel logistic regression models were used to estimate odds of good or better SRH by Latino residential segregation, measured by the Gini coefficient, and controlling for sociodemographic, acculturation and social capital measures of neighborhood ties, collective socialization of children, and social control. The Latino residential segregation - SRH relationship was convex, or 'U'-shaped, such that increases in segregation among Latinos residing in lower segregation areas was associated with lower SRH while increases in segregation among Latinos residing in higher segregation areas was associated with higher SRH. The social capital measures were independently associated with SRH but had little effect on the relationship between Latino residential segregation and SRH. A convex relationship between Latino residential segregation and SRH could explain mixed findings of previous studies. Although important for SRH, social capital measures of neighborhood ties, collective socialization of children, and social control might not account for the relationship between Latino residential segregation and SRH. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Revaluation of Indexes of Residential Segregation

ERIC Educational Resources Information Center

Winship, Christopher

1977-01-01

Shows that there are at least two different perspectives from which residential segregation can be examined. Segregation can be measured as it deviates from a situation of complete desegregation or in terms of a situation in which there is random segregation in the city. New criteria for indexes of residential segregation are developed. (Author/JM)

28 CFR 541.20 - Justification for placement in disciplinary segregation and review of inmates in disciplinary...

Code of Federal Regulations, 2010 CFR

2010-07-01

... disciplinary segregation and review of inmates in disciplinary segregation. 541.20 Section 541.20 Judicial... disciplinary segregation and review of inmates in disciplinary segregation. (a) Except as provided in paragraph... the physical confines of administrative detention, and (3) upon advice of appropriate medical staff...

43 CFR 3873.1 - Segregation of mineral from non-mineral land.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation of mineral from non-mineral... AND CONFLICTS Segregation § 3873.1 Segregation of mineral from non-mineral land. Where a survey is... satisfactorily established that there are existent prior unpatented mining claims, the segregation of the latter...

Income Segregation between Schools and School Districts. CEPA Working Paper No. 16-04

ERIC Educational Resources Information Center

Owens, Ann; Reardon, Sean F.; Jencks, Christopher

2016-01-01

Although trends in the racial segregation of schools are well documented, less is known about trends in "income" segregation. We use multiple data sources to document trends in income segregation between schools and school districts. Between-district income segregation of families with children enrolled in public school increased by over…

Segregation as Splitting, Segregation as Joining: Schools, Housing, and the Many Modes of Jim Crow

ERIC Educational Resources Information Center

Highsmith, Andrew R.; Erickson, Ansley T.

2015-01-01

Popular understandings of segregation often emphasize the Jim Crow South before the 1954 "Brown" decision and, in many instances, explain continued segregation in schooling as the result of segregated housing patterns. The case of Flint, Michigan, complicates these views, at once illustrating the depth of governmental commitment to…

A Naturalistic Observational Study of Informal Segregation: Seating Patterns in Lectures

ERIC Educational Resources Information Center

Koen, Jennifer; Durrheim, Kevin

2010-01-01

In spite of the removal of legislated racial segregation, a number of observational studies in South Africa and elsewhere have shown that "informal," nonlegislated segregation persists in spaces of everyday interaction. Most of these have been case studies of segregation at single sites. The authors seek to quantify segregation in a…

Multi-Contextual Segregation and Environmental Justice Research: Toward Fine-Scale Spatiotemporal Approaches.

PubMed

Park, Yoo Min; Kwan, Mei-Po

2017-10-10

Many environmental justice studies have sought to examine the effect of residential segregation on unequal exposure to environmental factors among different social groups, but little is known about how segregation in non-residential contexts affects such disparity. Based on a review of the relevant literature, this paper discusses the limitations of traditional residence-based approaches in examining the association between socioeconomic or racial/ethnic segregation and unequal environmental exposure in environmental justice research. It emphasizes that future research needs to go beyond residential segregation by considering the full spectrum of segregation experienced by people in various geographic and temporal contexts of everyday life. Along with this comprehensive understanding of segregation, the paper also highlights the importance of assessing environmental exposure at a high spatiotemporal resolution in environmental justice research. The successful integration of a comprehensive concept of segregation, high-resolution data and fine-grained spatiotemporal approaches to assessing segregation and environmental exposure would provide more nuanced and robust findings on the associations between segregation and disparities in environmental exposure and their health impacts. Moreover, it would also contribute to significantly expanding the scope of environmental justice research.

Luminosity segregation in galaxy clusters as an indication of dynamical evolution

NASA Technical Reports Server (NTRS)

Baier, F. W.; Schmidt, K.-H.

1993-01-01

Theoretical models describing the dynamical evolution of self-gravitating systems predict a spatial mass segregation for more evolved systems, with the more massive objects concentrated toward the center of the configuration. From the observational point of view, however, the existence of mass segregation in galaxy clusters seems to be a matter of controversy. A special problem in this connection is the formation of cD galaxies in the centers of galaxy clusters. The most promising scenarios of their formation are galaxy cannibalism (merger scenario) and growing by cooling flows. It seems to be plausible to consider the swallowing of smaller systems by a dominant galaxy as an important process in the evolution of a cD galaxy. The stage of the evolution of the dominant galaxy should be reflected by the surrounding galaxy population, especially by possible mass segregation effects. Assuming that mass segregation is tantamount to luminosity segregation we analyzed luminosity segregation in roughly 40 cD galaxy clusters. Obviously there are three different groups of clusters: (1) clusters with luminosity segregation, (2) clusters without luminosity segregation, and (3) such objects exhibiting a phenomenon which we call antisegregation in luminosity, i.e. a deficiency of bright galaxies in the central regions of clusters. This result is interpreted in the sense of different degrees of mass segregation and as an indication for different evolution stages of these clusters. The clusters are arranged in the three segregation classes 2, 1, and 0 (S2 = strong mass segregation, S1 = moderate mass segregation, S0 = weak or absent mass segregation). We assume that a galaxy cluster starts its dynamical evolution after virialization without any radial mass segregation. Energy exchange during encounters of cluster members as well as merger processes between cluster galaxies lead to an increasing radial mass segregation in the cluster (S1). If a certain degree of segregation (S2) has been established, an essential number of slow-moving and relative massive cluster members in the center will be cannibalized by the initial brightest cluster galaxy. This process should lead to the growing of the predominate galaxy, which is accompanied by a diminution of the mass segregation (transition to S1 and S0, respectively) in the neighborhood of the central very massive galaxy. An increase of the areal density of brighter galaxies towards the outer cluster regions (antisegregation of luminosity), i.e. an extreme low degree of mass segregation was estimated for a substantial percentage of cD clusters. This result favors the cannibalism scenario for the formation of cD galaxies.

Generative Models of Segregation: Investigating Model-Generated Patterns of Residential Segregation by Ethnicity and Socioeconomic Status

PubMed Central

Fossett, Mark

2011-01-01

This paper considers the potential for using agent models to explore theories of residential segregation in urban areas. Results of generative experiments conducted using an agent-based simulation of segregation dynamics document that varying a small number of model parameters representing constructs from urban-ecological theories of segregation can generate a wide range of qualitatively distinct and substantively interesting segregation patterns. The results suggest how complex, macro-level patterns of residential segregation can arise from a small set of simple micro-level social dynamics operating within particular urban-demographic contexts. The promise and current limitations of agent simulation studies are noted and optimism is expressed regarding the potential for such studies to engage and contribute to the broader research literature on residential segregation. PMID:21379372

Black-white metropolitan segregation and self-rated health: Investigating the role of neighborhood poverty.

PubMed

Do, D Phuong; Frank, Reanne; Iceland, John

2017-08-01

While black-white segregation has been consistently linked to detrimental health outcomes for blacks, whether segregation is necessarily a zero-sum arrangement in which some groups accrue health advantages at the expense of other groups and whether metropolitan segregation impacts the health of racial groups uniformly within the metropolitan area, remains unclear. Using nationally representative data from the 2008-2013 National Health Interview Survey linked to Census data, we investigate whether the association between metropolitan segregation and health is invariant within the metropolitan area or whether it is modified by neighborhood poverty for black and white Americans. In doing so, we assess the extent to which segregation involves direct health tradeoffs between blacks and whites. We conduct race-stratified multinomial and logistic regression models to assess the relationship between 1) segregation and level of neighborhood poverty and 2) segregation, neighborhood poverty, and poor health, respectively. We find that, for blacks, segregation was associated with a higher likelihood of residing in high poverty neighborhoods, net of individual-level socioeconomic characteristics. Segregation was positively associated with poor health for blacks in high poverty neighborhoods, but not for those in lower poverty neighborhoods. Hence, the self-rated health of blacks clearly suffers as a result of black-white segregation - both directly, and indirectly through exposure to high poverty neighborhoods. We do not find consistent evidence for a direct relationship between segregation and poor health for whites. However, we find some suggestive evidence that segregation may indirectly benefit whites through decreasing their exposure to high poverty environments. These findings underscore the critical role of concentrated disadvantage in the complex interconnection between metropolitan segregation and health. Weakening the link between racial segregation and concentrated poverty via local policy and planning has the potential for broad population-based health improvements and significant reductions in black-white health disparities. Copyright © 2017. Published by Elsevier Ltd.

Public school segregation and juvenile violent crime arrests in metropolitan areas.

PubMed

Eitle, David; Eitle, Tamela McNulty

2010-01-01

Previous research has established an association between residential segregation and violent crime in urban America. Our study examines whether school-based segregation is predictive of arrests of juveniles for violent crimes in U.S. metro areas. Using Census, Uniform Crime Report, and Common Core data for 204 metro areas, a measure of school-based racial segregation, Theil's entropy index, is decomposed into two components: between- and within-district segregation. Findings reveal evidence of a significant interaction term: Within-district segregation is inversely associated with arrests for juvenile violence, but only in metropolitan areas with higher than average levels of between-district segregation.

Influence of the "surface effect" on the segregation parameters of S in Fe(100): A multi-scale modelling and Auger Electron Spectroscopy study

NASA Astrophysics Data System (ADS)

Barnard, P. E.; Terblans, J. J.; Swart, H. C.

2015-12-01

The article takes a new look at the process of atomic segregation by considering the influence of surface relaxation on the segregation parameters; the activation energy (Q), segregation energy (ΔG), interaction parameter (Ω) and the pre-exponential factor (D0). Computational modelling, namely Density Functional Theory (DFT) and the Modified Darken Model (MDM) in conjunction with Auger Electron Spectroscopy (AES) was utilized to study the variation of the segregation parameters for S in the surface region of Fe(100). Results indicate a variation in each of the segregation parameters as a function of the atomic layer under consideration. Values of the segregation parameters varied more dramatically as the surface layer is approached, with atomic layer 2 having the largest deviations in comparison to the bulk values. This atomic layer had the highest Q value and formed the rate limiting step for the segregation of S towards the Fe(100) surface. It was found that the segregation process is influenced by two sets of segregation parameters, those of the surface region formed by atomic layer 2, and those in the bulk material. This article is the first to conduct a full scale investigation on the influence of surface relaxation on segregation and labelled it the "surface effect".

Gender Segregation in the Spanish Labor Market: An Alternative Approach

ERIC Educational Resources Information Center

del Rio, Coral; Alonso-Villar, Olga

2010-01-01

The aim of this paper is to study occupational segregation by gender in Spain, which is a country where occupational segregation explains a large part of the gender wage gap. As opposed to previous studies, this paper measures not only overall segregation, but also the segregation of several population subgroups. For this purpose, this paper uses…

The Growth of Segregation in American Schools: Changing Patterns of Separation and Poverty since 1968.

ERIC Educational Resources Information Center

Orfield, Gary; And Others

This study shows where school segregation is concentrated and where schools remain highly integrated. It offers the first national comparison of segregation by community size and reveals that segregation remains high in big cities and serious in mid-size central cities. Many African-American and Latino students also attend segregated schools in…

Residential segregation and racial disparities in self-rated health: How do dimensions of residential segregation matter?1

PubMed Central

Yang, Tse-Chuan; Zhao, Yunhan; Song, Qian

2016-01-01

Previous research on segregation and health has been criticized for overlooking the fact that segregation is a multi-dimensional concept (i.e., evenness, exposure, concentration, centralization, and clustering) and recent evidence drawn from non-black minorities challenges the conventional belief that residential segregation widens racial health disparities. Combining a survey data (n=18,752) from Philadelphia with the 2010 Census tract (n=925) data, we examine two theoretical frameworks to understand why the association of segregation with health may differ by race/ethnicity. Specifically, we investigate how each dimension of segregation contributed to racial disparities in self-rated health. We found (1) high levels of white/ black concentration could exacerbate the white/black health disparities up to 25 percent, (2) the white/Hispanic health disparities was narrowed by increasing the level of white/Hispanic centralization, and (3) no single dimension of segregation statistically outperforms others. Our findings supported that segregation is bad for blacks but may be beneficial for Hispanics. PMID:27886735

Micro and Macro Segregation in Alloys Solidifying with Equiaxed Morphology

NASA Technical Reports Server (NTRS)

Stefanescu, Doru M.; Curreri, Peter A.; Leon-Torres, Jose; Sen, Subhayu

1996-01-01

To understand macro segregation formation in Al-Cu alloys, experiments were run under terrestrial gravity (1g) and under low gravity during parabolic flights (10(exp -2) g). Alloys of two different compositions (2% and 5% Cu) were solidified at two different cooling rates. Systematic microscopic and SEM observations produced microstructural and segregation maps for all samples. These maps may be used as benchmark experiments for validation of microstructure evolution and segregation models. As expected, the macro segregation maps are very complex. When segregation was measured along the central axis of the sample, the highest macro segregation for samples solidified at 1g was obtained for the lowest cooling rate. This behavior is attributed to the longer time available for natural convection and shrinkage flow to affect solute redistribution. In samples solidified under low-g, the highest macro-segregation was obtained at the highest cooling rate. In general, low-gravity solidification resulted in less segregation. To explain the experimental findings, an analytical (Flemings-Nereo) and a numerical model were used. For the numerical model, the continuum formulation was employed to describe the macroscopic transports of mass, energy, and momentum, associated with the microscopic transport phenomena, for a two-phase system. The model proposed considers that liquid flow is driven by thermal and solutal buoyancy, and by solidification shrinkage. The Flemings-Nereo model explains well macro segregation in the initial stages of low-gravity segregation. The numerical model can describe the complex macro segregation pattern and the differences between low- and high-gravity solidification.

Two critical periods in early visual cortex during figure-ground segregation.

PubMed

Wokke, Martijn E; Sligte, Ilja G; Steven Scholte, H; Lamme, Victor A F

2012-11-01

The ability to distinguish a figure from its background is crucial for visual perception. To date, it remains unresolved where and how in the visual system different stages of figure-ground segregation emerge. Neural correlates of figure border detection have consistently been found in early visual cortex (V1/V2). However, areas V1/V2 have also been frequently associated with later stages of figure-ground segregation (such as border ownership or surface segregation). To causally link activity in early visual cortex to different stages of figure-ground segregation, we briefly disrupted activity in areas V1/V2 at various moments in time using transcranial magnetic stimulation (TMS). Prior to stimulation we presented stimuli that made it possible to differentiate between figure border detection and surface segregation. We concurrently recorded electroencephalographic (EEG) signals to examine how neural correlates of figure-ground segregation were affected by TMS. Results show that disruption of V1/V2 in an early time window (96-119 msec) affected detection of figure stimuli and affected neural correlates of figure border detection, border ownership, and surface segregation. TMS applied in a relatively late time window (236-259 msec) selectively deteriorated performance associated with surface segregation. We conclude that areas V1/V2 are not only essential in an early stage of figure-ground segregation when figure borders are detected, but subsequently causally contribute to more sophisticated stages of figure-ground segregation such as surface segregation.

Two critical periods in early visual cortex during figure–ground segregation

PubMed Central

Wokke, Martijn E; Sligte, Ilja G; Steven Scholte, H; Lamme, Victor A F

2012-01-01

The ability to distinguish a figure from its background is crucial for visual perception. To date, it remains unresolved where and how in the visual system different stages of figure–ground segregation emerge. Neural correlates of figure border detection have consistently been found in early visual cortex (V1/V2). However, areas V1/V2 have also been frequently associated with later stages of figure–ground segregation (such as border ownership or surface segregation). To causally link activity in early visual cortex to different stages of figure–ground segregation, we briefly disrupted activity in areas V1/V2 at various moments in time using transcranial magnetic stimulation (TMS). Prior to stimulation we presented stimuli that made it possible to differentiate between figure border detection and surface segregation. We concurrently recorded electroencephalographic (EEG) signals to examine how neural correlates of figure–ground segregation were affected by TMS. Results show that disruption of V1/V2 in an early time window (96–119 msec) affected detection of figure stimuli and affected neural correlates of figure border detection, border ownership, and surface segregation. TMS applied in a relatively late time window (236–259 msec) selectively deteriorated performance associated with surface segregation. We conclude that areas V1/V2 are not only essential in an early stage of figure–ground segregation when figure borders are detected, but subsequently causally contribute to more sophisticated stages of figure–ground segregation such as surface segregation. PMID:23170239

43 CFR 2091.5-1 - Segregation of lands resulting from withdrawal applications filed on or after October 21, 1976.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation of lands resulting from... RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.5-1 Segregation... publication and extends for a period of 2 years unless sooner terminated as set out below. (b) Segregations...

43 CFR 2091.5-2 - Segregation of lands resulting from withdrawal applications filed prior to October 21, 1976.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation of lands resulting from... RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.5-2 Segregation... modifies the term of segregation for all lands covered by the amended application to conform with the...

Multi-Contextual Segregation and Environmental Justice Research: Toward Fine-Scale Spatiotemporal Approaches

PubMed Central

Park, Yoo Min; Kwan, Mei-Po

2017-01-01

Many environmental justice studies have sought to examine the effect of residential segregation on unequal exposure to environmental factors among different social groups, but little is known about how segregation in non-residential contexts affects such disparity. Based on a review of the relevant literature, this paper discusses the limitations of traditional residence-based approaches in examining the association between socioeconomic or racial/ethnic segregation and unequal environmental exposure in environmental justice research. It emphasizes that future research needs to go beyond residential segregation by considering the full spectrum of segregation experienced by people in various geographic and temporal contexts of everyday life. Along with this comprehensive understanding of segregation, the paper also highlights the importance of assessing environmental exposure at a high spatiotemporal resolution in environmental justice research. The successful integration of a comprehensive concept of segregation, high-resolution data and fine-grained spatiotemporal approaches to assessing segregation and environmental exposure would provide more nuanced and robust findings on the associations between segregation and disparities in environmental exposure and their health impacts. Moreover, it would also contribute to significantly expanding the scope of environmental justice research. PMID:28994744

Continuum modelling of segregating tridisperse granular chute flow

NASA Astrophysics Data System (ADS)

Deng, Zhekai; Umbanhowar, Paul B.; Ottino, Julio M.; Lueptow, Richard M.

2018-03-01

Segregation and mixing of size multidisperse granular materials remain challenging problems in many industrial applications. In this paper, we apply a continuum-based model that captures the effects of segregation, diffusion and advection for size tridisperse granular flow in quasi-two-dimensional chute flow. The model uses the kinematics of the flow and other physical parameters such as the diffusion coefficient and the percolation length scale, quantities that can be determined directly from experiment, simulation or theory and that are not arbitrarily adjustable. The predictions from the model are consistent with experimentally validated discrete element method (DEM) simulations over a wide range of flow conditions and particle sizes. The degree of segregation depends on the Péclet number, Pe, defined as the ratio of the segregation rate to the diffusion rate, the relative segregation strength κij between particle species i and j, and a characteristic length L, which is determined by the strength of segregation between smallest and largest particles. A parametric study of particle size, κij, Pe and L demonstrates how particle segregation patterns depend on the interplay of advection, segregation and diffusion. Finally, the segregation pattern is also affected by the velocity profile and the degree of basal slip at the chute surface. The model is applicable to different flow geometries, and should be easily adapted to segregation driven by other particle properties such as density and shape.

43 CFR 2091.5-3 - Segregative effect and opening: Emergency withdrawals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... RULES Segregation and Opening of Lands § 2091.5-3 Segregative effect and opening: Emergency withdrawals... withdrawal unless segregation is effected by the publication in the Federal Register of a notice of a...

Racial Residential Segregation and STI Diagnosis Among Non-Hispanic Blacks, 2006-2010.

PubMed

Lutfi, Khaleeq; Trepka, Mary Jo; Fennie, Kristopher P; Ibañez, Gladys; Gladwin, Hugh

2018-06-01

Sexually transmitted infections (STI) disproportionately impact non-Hispanic blacks. Racial residential segregation has been associated with negative socioeconomic outcomes. We sought to examine the association between segregation and STI diagnosis among blacks. The National Survey of Family Growth and US Census served as data sources. Five distinct dimensions represent segregation. The association between STI diagnosis and each segregation dimension was assessed with multilevel logistic regression modeling. 305 (7.4%) blacks reported STI diagnosis during the past 12 months. Depending on the dimension, segregation was a risk factor [dissimilarity aOR 2.41 (95% CI 2.38-2.43)] and a protective factor [isolation aOR 0.90 (95% CI 0.89-0.91)] for STI diagnosis. Findings suggest that STI diagnosis among blacks is associated with segregation. Additional research is needed to identify mechanisms for how segregation affects STI diagnosis and to aid in the development of interventions to decrease STIs.

Neighborhood residential segregation and mental health: a multilevel analysis on Hispanic Americans in Chicago.

PubMed

Lee, Min-Ah

2009-06-01

Compared with the relationship between neighborhood-level residential segregation and physical health of Hispanic Americans, less is known about how neighborhood residential segregation affects mental health. This study examines if, and how, neighborhood residential segregation is associated with the mental health of Puerto Rican and Mexican Americans in Chicago. Multilevel analyses reveal that neighborhood residential segregation is positively associated with depressive symptoms and anxiety in both groups. Neighborhood segregation, however, has more salient effects on the mental health of Mexican Americans. For Puerto Rican Americans, the effects of neighborhood segregation on mental health become nonsignificant after controlling for neighborhood-level income and individual-level covariates, whereas neighborhood segregation is strongly associated with the mental health of Mexican Americans even after controlling for other covariates. These findings show that living in a Mexican American-dominated community is not beneficial to mental health, in contrast to findings for physical health shown in previous studies.

Neighborhood residential segregation and physical health among Hispanic Americans: good, bad, or benign?

PubMed

Lee, Min-Ah; Ferraro, Kenneth F

2007-06-01

Although considerable evidence shows that residential segregation is deleterious to the health of African Americans, findings regarding segregation and health for Hispanic Americans are inconsistent. Competing hypotheses regarding the effects of neighborhood segregation on health are tested with data from Puerto Rican and Mexican American residents of Chicago. Multilevel analyses reveal that segregation is associated with more health problems for Puerto Rican Americans but not for Mexican Americans. In addition, the relationship between segregation and health was conditioned by generational status for Mexican Americans: Second- or later-generation Mexican Americans living in highly segregated neighborhoods had better health than first-generation Mexican Americans in such neighborhoods. These findings reveal that residential segregation has differential effects across Hispanic groups and suggest that a high degree of contact with Mexican Americans promotes health by facilitating flow of informal health resources and social support.

Analysis of Minor Component Segregation in Ternary Powder Mixtures

NASA Astrophysics Data System (ADS)

Asachi, Maryam; Hassanpour, Ali; Ghadiri, Mojtaba; Bayly, Andrew

2017-06-01

In many powder handling operations, inhomogeneity in powder mixtures caused by segregation could have significant adverse impact on the quality as well as economics of the production. Segregation of a minor component of a highly active substance could have serious deleterious effects, an example is the segregation of enzyme granules in detergent powders. In this study, the effects of particle properties and bulk cohesion on the segregation tendency of minor component are analysed. The minor component is made sticky while not adversely affecting the flowability of samples. The segregation extent is evaluated using image processing of the photographic records taken from the front face of the heap after the pouring process. The optimum average sieve cut size of components for which segregation could be reduced is reported. It is also shown that the extent of segregation is significantly reduced by applying a thin layer of liquid to the surfaces of minor component, promoting an ordered mixture.

The Integration Anomaly: Comparing the Effects of K-12 Education Delivery Models on Segregation in Schools

ERIC Educational Resources Information Center

Scafidi, Benjamin

2015-01-01

To shed light on the actual impact of school choice on segregation, one has to understand the counter factual--the state of segregation under the current public education system. In the late 1960s and '70s, the trend in public school racial segregation followed the trend in neighborhood segregation. That is to say both improved as American…

Asymmetric segregation of template DNA strands in basal-like human breast cancer cell lines

PubMed Central

2013-01-01

Background and methods Stem or progenitor cells from healthy tissues have the capacity to co-segregate their template DNA strands during mitosis. Here, we set out to test whether breast cancer cell lines also possess the ability to asymmetrically segregate their template DNA strands via non-random chromosome co-segregation, and whether this ability correlates with certain properties attributed to breast cancer stem cells (CSCs). We quantified the frequency of asymmetric segregation of template DNA strands in 12 human breast cancer cell lines, and correlated the frequency to molecular subtype, CD44+/CD24-/lo phenotype, and invasion/migration ability. We tested if co-culture with human mesenchymal stem cells, which are known to increase self-renewal, can alter the frequency of asymmetric segregation of template DNA in breast cancer. Results We found a positive correlation between asymmetric segregation of template DNA and the breast cancer basal-like and claudin-low subtypes. There was an inverse correlation between asymmetric segregation of template DNA and Her2 expression. Breast cancer samples with evidence of asymmetric segregation of template DNA had significantly increased invasion and borderline significantly increased migration abilities. Samples with high CD44+/CD24-/lo surface expression were more likely to harbor a consistent population of cells that asymmetrically segregated its template DNA; however, symmetric self-renewal was enriched in the CD44+/CD24-/lo population. Co-culturing breast cancer cells with human mesenchymal stem cells expanded the breast CSC pool and decreased the frequency of asymmetric segregation of template DNA. Conclusions Breast cancer cells within the basal-like subtype can asymmetrically segregate their template DNA strands through non-random chromosome segregation. The frequency of asymmetric segregation of template DNA can be modulated by external factors that influence expansion or self-renewal of CSC populations. Future studies to uncover the underlying mechanisms driving asymmetric segregation of template DNA and dictating cell fate at the time of cell division may explain how CSCs are maintained in tumors. PMID:24238140

7 CFR 996.13 - Peanuts.

Code of Federal Regulations, 2014 CFR

2014-01-01

... from visible Aspergillus flavus. (c) Segregation 2. “Segregation 2 peanuts” means farmers stock peanuts... rancidity, mold, or decay and which are free from visible Aspergillus flavus. (d) Segregation 3. “Segregation 3 peanuts” means farmers stock peanuts with visible Aspergillus flavus. ...

7 CFR 996.13 - Peanuts.

Code of Federal Regulations, 2013 CFR

2013-01-01

... from visible Aspergillus flavus. (c) Segregation 2. “Segregation 2 peanuts” means farmers stock peanuts... rancidity, mold, or decay and which are free from visible Aspergillus flavus. (d) Segregation 3. “Segregation 3 peanuts” means farmers stock peanuts with visible Aspergillus flavus. ...

7 CFR 996.13 - Peanuts.

Code of Federal Regulations, 2012 CFR

2012-01-01

... from visible Aspergillus flavus. (c) Segregation 2. “Segregation 2 peanuts” means farmers stock peanuts... rancidity, mold, or decay and which are free from visible Aspergillus flavus. (d) Segregation 3. “Segregation 3 peanuts” means farmers stock peanuts with visible Aspergillus flavus. ...

Undocumented Migration and the Residential Segregation of Mexicans in New Destinations1

PubMed Central

Hall, Matthew; Stringfield, Jonathan

2014-01-01

This study uses data from the 2000 Census and 2005–2009 American Community Survey to examine the impact of undocumented Mexican migration to new destinations on residential segregation between Mexican immigrants and native-born whites and native-born blacks. We find that Mexican-white and Mexican-black segregation is higher in new Mexican gateways than in established areas and that, for Mexican-immigrant segregation from whites, this heightened level of residential segregation in new destinations can be explained by the high presence of unauthorized Mexican immigrants living there which tends to bolster segregation between the two groups. By contrast, Mexican-immigrant segregation from native-born blacks tends to be lower in areas with larger undocumented populations, a pattern that is especially true in new destinations. Neither of these opposing effects of legal status on Mexican-immigrant segregation can be explained by compositional differences in assimilation (English ability and earnings) between documented and undocumented immigrants nor by structural variation in metropolitan areas, suggesting a unique association between legal status and segregation. PMID:24913945

Residential Segregation and School Integration.

ERIC Educational Resources Information Center

Rivkin, Steven G.

1994-01-01

Asserts that school districts' efforts to integrate schools have failed to ameliorate the racial isolation of black students. Finds that schools remain segregated primarily because of continued residential segregation and that school integration efforts have had little long-term effect on residential segregation. (CFR)

Sound segregation via embedded repetition is robust to inattention.

PubMed

Masutomi, Keiko; Barascud, Nicolas; Kashino, Makio; McDermott, Josh H; Chait, Maria

2016-03-01

The segregation of sound sources from the mixture of sounds that enters the ear is a core capacity of human hearing, but the extent to which this process is dependent on attention remains unclear. This study investigated the effect of attention on the ability to segregate sounds via repetition. We utilized a dual task design in which stimuli to be segregated were presented along with stimuli for a "decoy" task that required continuous monitoring. The task to assess segregation presented a target sound 10 times in a row, each time concurrent with a different distractor sound. McDermott, Wrobleski, and Oxenham (2011) demonstrated that repetition causes the target sound to be segregated from the distractors. Segregation was queried by asking listeners whether a subsequent probe sound was identical to the target. A control task presented similar stimuli but probed discrimination without engaging segregation processes. We present results from 3 different decoy tasks: a visual multiple object tracking task, a rapid serial visual presentation (RSVP) digit encoding task, and a demanding auditory monitoring task. Load was manipulated by using high- and low-demand versions of each decoy task. The data provide converging evidence of a small effect of attention that is nonspecific, in that it affected the segregation and control tasks to a similar extent. In all cases, segregation performance remained high despite the presence of a concurrent, objectively demanding decoy task. The results suggest that repetition-based segregation is robust to inattention. (c) 2016 APA, all rights reserved).

Twenty Years after Brown: Where Are We Now?

ERIC Educational Resources Information Center

Edelman, Marian Wright

1974-01-01

To resolve the basic question of what is unconstitutional school segregation, lawyer Edelman suggests bombarding the citadel of de facto segregation with a legal strategy that expands the definition of de jure segregation to include acts that produce segregation in fact. (Editor)

49 CFR 175.78 - Stowage compatibility of cargo.

Code of Federal Regulations, 2010 CFR

2010-10-01

... leakage. (b) At a minimum, the segregation instructions prescribed in the following Segregation Table must be followed to maintain acceptable segregation between packages containing hazardous materials with different hazards. The Segregation Table instructions apply whether or not the class or division is the...

Quality-by-design (QbD): effects of testing parameters and formulation variables on the segregation tendency of pharmaceutical powder measured by the ASTM D 6940-04 segregation tester.

PubMed

Xie, Lin; Wu, Huiquan; Shen, Meiyu; Augsburger, Larry L; Lyon, Robbe C; Khan, Mansoor A; Hussain, Ajaz S; Hoag, Stephen W

2008-10-01

The objective of this study was to examine the effects of testing parameters and formulation variables on the segregation tendency of pharmaceutical powders measured by the ASTM D 6940-04 segregation tester using design of experiments (DOE) approaches. The test blends consisted of 4% aspirin (ASP) and 96% microcrystalline cellulose (MCC) with and without magnesium stearate (MgS). The segregation tendency of a blend was determined by measuring the last/first (L/F) ratio, the ratio of aspirin concentrations between the first and last samples discharged from the tester. A 2(2) factorial design was used to determine the effects of measurement parameters [amount of material loaded (W), number of segregation cycles] with number of replicates 6. ANOVA showed that W was a critical parameter for segregation testing. The L/F value deviated further from 1 (greater segregation tendency) with increasing W. A 2(3) full factorial design was used to assess the effects of formulation variables: grade of ASP (unmilled, milled), grade of MCC, and amount of lubricant, MgS. MLR and ANOVA showed that the grade of ASP was the main effect contributing to segregation tendency. Principal Component Regression Analysis established a correlation between L/F and the physical properties of the blend related to ASP and MCC, the ASP/MCC particle size ratio (PSR) and powder cohesion. The physical properties of the blend related to density and flow were not influenced by the grade of ASP and were not related to the segregation tendency of the blend. The direct relationship between L/F and PSR was determined by univariate analysis. Segregation tendency increased as the ASP to MCC particle size increased. This study highlighted critical test parameters for segregation testing and identified critical physical properties of the blends that influence segregation tendency. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

18 CFR 401.113 - Segregable materials.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any person...

18 CFR 401.113 - Segregable materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any person...

18 CFR 401.113 - Segregable materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any person...

18 CFR 401.113 - Segregable materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Segregable materials. 401.113 Section 401.113 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION... Segregable materials. Any reasonably segregable portion of a record shall be provided to any person...

49 CFR 176.708 - Segregation distances.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Segregation distances. 176.708 Section 176.708... Requirements for Radioactive Materials § 176.708 Segregation distances. (a) Table IV lists minimum separation... into account any relocation of cargo during the voyage. (e) Any departure from the segregation...

49 CFR 176.145 - Segregation in single hold vessels.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Segregation in single hold vessels. 176.145 Section 176.145 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.145 Segregation in...

43 CFR 2091.07 - Principles.

Code of Federal Regulations, 2011 CFR

2011-10-01

... OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of... the Geothermal Steam Act, if so specified in the document that segregates the lands. The segregation... are required when the opening date is not specified in the document creating the segregation, or when...

49 CFR 176.145 - Segregation in single hold vessels.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Segregation in single hold vessels. 176.145 Section 176.145 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS... VESSEL Detailed Requirements for Class 1 (Explosive) Materials Segregation § 176.145 Segregation in...

The joint effect of ethnicity and gender on occupational segregation. An approach based on the Mutual Information Index.

PubMed

Guinea-Martin, Daniel; Mora, Ricardo; Ruiz-Castillo, Javier

2015-01-01

In this article, we study the effects of ethnicity and gender on occupational segregation. Traditionally, researchers have examined the two sources of segregation separately. In contrast, we measure their joint effect by applying a multigroup segregation index-the Mutual Information or M index-to the product of the seven ethnic groups and two genders distinguished in our 2001 Census data for England and Wales. We exploit M's additive decomposability property to pose the following two questions: (i) Is there an interaction effect? (ii) How much does each source contribute to occupational segregation, controlling for the effect of the other? Although the role of ethnicity is non-negligible in the areas where minorities are concentrated, our findings confirm the greater importance of gender over ethnicity as a source of segregation. Moreover, we find a small "dwindling" interaction effect between the two sources of segregation: ethnicity slightly weakens the segregating power of gender and vice versa. Copyright © 2014 Elsevier Inc. All rights reserved.

Factors shaping workplace segregation between natives and immigrants.

PubMed

Strömgren, Magnus; Tammaru, Tiit; Danzer, Alexander M; van Ham, Maarten; Marcińczak, Szymon; Stjernström, Olof; Lindgren, Urban

2014-04-01

Research on segregation of immigrant groups is increasingly turning its attention from residential areas toward other important places, such as the workplace, where immigrants can meet and interact with members of the native population. This article examines workplace segregation of immigrants. We use longitudinal, georeferenced Swedish population register data, which enables us to observe all immigrants in Sweden for the period 1990-2005 on an annual basis. We compare estimates from ordinary least squares with fixed-effects regressions to quantify the extent of immigrants' self-selection into specific workplaces, neighborhoods, and partnerships, which may bias more naïve ordinary least squares results. In line with previous research, we find lower levels of workplace segregation than residential segregation. The main finding is that low levels of residential segregation reduce workplace segregation, even after we take into account intermarriage with natives as well as unobserved characteristics of immigrants' such as willingness and ability to integrate into the host society. Being intermarried with a native reduces workplace segregation for immigrant men but not for immigrant women.

Local Residential Segregation Matters: Stronger Association of Census Tract Compared to Conventional City-Level Measures with Fatal and Non-Fatal Assaults (Total and Firearm Related), Using the Index of Concentration at the Extremes (ICE) for Racial, Economic, and Racialized Economic Segregation, Massachusetts (US), 1995-2010.

PubMed

Krieger, Nancy; Feldman, Justin M; Waterman, Pamela D; Chen, Jarvis T; Coull, Brent A; Hemenway, David

2017-04-01

Research on residential segregation and health, primarily conducted in the USA, has chiefly employed city or regional measures of racial segregation. To test our hypothesis that stronger associations would be observed using local measures, especially for racialized economic segregation, we analyzed risk of fatal and non-fatal assault in Massachusetts (1995-2010), since this outcome is strongly associated with residential segregation. The segregation metrics comprised the Index of Concentration at the Extremes (ICE), the Index of Dissimilarity, and poverty rate, with measures computed at both the census tract and city/town level. Key results were that larger associations between fatal and non-fatal assaults and residential segregation occurred for models using the census tract vs. city/town measures, with the greatest associations observed for racialized economic segregation. For fatal assaults, comparing the bottom vs. top quintiles, the incidence rate ratio (and 95% confidence interval (CI)) in models using the census tract measures equaled 3.96 (95% CI 3.10, 5.06) for the ICE for racialized economic segregation, 3.26 (95% CI 2.58, 4.14) for the ICE for income, 3.14 (95% CI 2.47, 3.99) for poverty, 2.90 (95% CI 2.21, 3.81) for the ICE for race/ethnicity, and only 0.93 (95% CI 0.79, 1.11) for the Index of Dissimilarity; in models that included both census tract and city/town ICE measures, this risk ratio for the ICE for racialized economic segregation was higher at the census tract (3.29; 95% CI 2.43, 4.46) vs. city/town level (1.61; 95% CI 1.12, 2.32). These results suggest that, at least in the case of fatal and non-fatal assaults, research on residential segregation should employ local measures, including of racialized economic segregation, to avoid underestimating the adverse impact of segregation on health.

DNA and origin region segregation are not affected by the transition from rod to sphere after inhibition of Escherichia coli MreB by A22.

PubMed

Karczmarek, Aneta; Martínez-Arteaga, Rocío; Baselga, Rocío Martínez-Arteaga; Alexeeva, Svetlana; Hansen, Flemming G; Vicente, Miguel; Nanninga, Nanne; den Blaauwen, Tanneke

2007-07-01

The bacterial actin homologue MreB forms a helix underneath the cytoplasmic membrane and was shown to be essential in the morphogenesis of the rod-shaped cells. Additionally, MreB was implicated to be involved in DNA segregation. However, in our hands the mreBCD deletion strain (PA340-678) grew without apparent DNA segregation defect, suggesting that the reported chromosome segregation inhibition could be caused by a temporarily effect of MreB inhibition or depletion. To assess the involvement of MreB in DNA segregation during the transition from rod to sphere, we compared the effect of A22 and the PBP2 inhibitor mecillinam on the percentage of cells with segregated nucleoids and the number of oriC foci in wild-type Escherichia coli cells. Cells became spherical in the same time window during both treatments and we could not detect any difference in the chromosome or oriC segregation between these two treatments. Additionally, flow cytometric analyses showed that A22 and mecillinam treatment gave essentially the same chromosome segregation pattern. We conclude that MreB is not directly involved in DNA segregation of E. coli.

C-Cr segregation at grain boundary before the carbide nucleation in Alloy 690

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

Li Hui, E-mail: huili@shu.edu.cn; Laboratory for Microstructures, Shanghai University, Shanghai, 200444; Xia Shuang

2012-04-15

The grain boundary segregation in Alloy 690 was investigated by atom probe tomography. B, C and Si segregated at the grain boundary. The high concentration regions for each segregation element form a set of straight arrays that are parallel to each other in the grain boundary plane. The concentration fluctuation has a periodicity of about 7 nm in the grain boundary plane. Before the Cr{sub 23}C{sub 6} nucleation at grain boundaries, the C-Cr co-segregate on one side of the grain boundaries while not the exact grain boundary core regions have been detected. The reasons why grain boundary carbides have coherentmore » orientation relationship only with one side of nearby grain which grain boundary is located at high index crystal plane were discussed. - Highlights: Black-Right-Pointing-Pointer Grain boundary segregation in Alloy 690 was investigated by atom probe tomography. Black-Right-Pointing-Pointer B, C and Si segregate at the grain boundary. Black-Right-Pointing-Pointer Concentration of segregated atoms periodicity fluctuated in the grain boundary plane. Black-Right-Pointing-Pointer C and Cr co-segregate on one side of the grain boundary before carbide nucleation.« less

How Segregation Makes Us Fat: Food Behaviors and Food Environment as Mediators of the Relationship Between Residential Segregation and Individual Body Mass Index.

PubMed

Goodman, Melody; Lyons, Sarah; Dean, Lorraine T; Arroyo, Cassandra; Hipp, James Aaron

2018-01-01

Racial residential segregation affects food landscapes that dictate residents' food environments and is associated with obesity risk factors, including individual dietary patterns and behaviors. We examine if food behaviors and environments mediate the association between segregation and body mass index (BMI). Non-Hispanic Whites and Blacks living in the St. Louis and Kansas City metro regions from 2012 to 2013 were surveyed on dietary behaviors, food environment, and BMI ( n  = 1,412). These data were combined with the CDC's modified retail food environment index and 2012 American Community Survey data to calculate racial segregation using various evenness and exposure indices. Multi-level mediation analyses were conducted to determine if dietary behavior and food environment mediate the association between racial residential segregation and individual BMI. The positive association between racial segregation and individual BMI is partially mediated by dietary behaviors and fully mediated by food environments. Racial segregation (evenness and exposure) is associated with BMI, mediated by dietary behaviors and food environment. Elements of the food environment, which form the context for dietary behaviors, are potential targets for interventions to reduce obesity in residentially segregated areas.

Health Care Waste Segregation Behavior among Health Workers in Uganda: An Application of the Theory of Planned Behavior.

PubMed

Akulume, Martha; Kiwanuka, Suzanne N

2016-01-01

Objective . The goal of this study was to assess the appropriateness of the theory of planned behavior in predicting health care waste segregation behaviors and to examine the factors that influence waste segregation behaviors. Methodology . One hundred and sixty-three health workers completed a self-administered questionnaire in a cross-sectional survey that examined the theory of planned behavior constructs (attitudes, subjective norms, perceived behavioral control, and intention) and external variables (sociodemographic factors, personal characteristics, organizational characteristics, professional characteristics, and moral obligation). Results . For their most recent client 21.5% of the health workers reported that they most definitely segregated health care waste while 5.5% did not segregate. All the theory of planned behavior constructs were significant predictors of health workers' segregation behavior, but intention emerged as the strongest and most significant ( r = 0.524, P < 0.001). The theory of planned behavior model explained 52.5% of the variance in health workers' segregation behavior. When external variables were added, the new model explained 66.7% of the variance in behavior. Conclusion . Generally, health workers' health care waste segregation behavior was high. The theory of planned behavior significantly predicted health workers' health care waste segregation behaviors.

Sequential stream segregation in normally-hearing and cochlear-implant listenersa)

PubMed Central

Tejani, Viral D.; Schvartz-Leyzac, Kara C.; Chatterjee, Monita

2017-01-01

Sequential stream segregation by normal hearing (NH) and cochlear implant (CI) listeners was investigated using an irregular rhythm detection (IRD) task. Pure tones and narrowband noises of different bandwidths were presented monaurally to older and younger NH listeners via headphones. For CI users, stimuli were delivered as pure tones via soundfield and via direct electrical stimulation. Results confirmed that tonal pitch is not essential for stream segregation by NH listeners and that aging does not reduce NH listeners' stream segregation. CI listeners' stream segregation was significantly poorer than NH listeners' with pure tone stimuli. With direct stimulation, however, CI listeners showed significantly stronger stream segregation, with a mean normalized pattern similar to NH listeners, implying that the CI speech processors possibly degraded acoustic cues. CI listeners' performance on an electrode discrimination task indicated that cues that are salient enough to make two electrodes highly discriminable may not be sufficiently salient for stream segregation, and that gap detection/discrimination, which must depend on perceptual electrode differences, did not play a role in the IRD task. Although the IRD task does not encompass all aspects of full stream segregation, these results suggest that some CI listeners may demonstrate aspects of stream segregation. PMID:28147600

27 CFR 24.27 - Segregation of operations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Segregation of operations. 24.27 Section 24.27 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Segregation of operations. The appropriate TTB officer may require the proprietor to segregate operations...

27 CFR 24.27 - Segregation of operations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Segregation of operations. 24.27 Section 24.27 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU... Segregation of operations. The appropriate TTB officer may require the proprietor to segregate operations...

28 CFR 541.24 - Disciplinary segregation status.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Disciplinary segregation status. 541.24... INMATE DISCIPLINE AND SPECIAL HOUSING UNITS Special Housing Units § 541.24 Disciplinary segregation status. You may be placed in disciplinary segregation status only by the DHO as a disciplinary sanction. ...

Racial and Ethnic Residential Segregation, the Neighborhood Socioeconomic Environment, and Obesity Among Blacks and Mexican Americans

PubMed Central

Kershaw, Kiarri N.; Albrecht, Sandra S.; Carnethon, Mercedes R.

2013-01-01

We used cross-sectional data on 2,660 black and 2,611 Mexican-American adult participants in the National Health and Nutrition Examination Survey (1999–2006) to investigate the association between metropolitan-level racial/ethnic residential segregation and obesity and to determine whether it was mediated by the neighborhood socioeconomic environment. Residential segregation was measured using the black and Hispanic isolation indices. Neighborhood poverty and negative income incongruity were assessed as mediators. Multilevel Poisson regression with robust variance estimates was used to estimate prevalence ratios. There was no relationship between segregation and obesity among men. Among black women, in age-, nativity-, and metropolitan demographic-adjusted models, high segregation was associated with a 1.29 (95% confidence interval (CI): 1.00, 1.65) times higher obesity prevalence than was low segregation; medium segregation was associated with a 1.35 (95% CI: 1.07, 1.70) times higher obesity prevalence. Mexican-American women living in high versus low segregation areas had a significantly lower obesity prevalence (prevalence ratio, 0.54; 95% CI: 0.33, 0.90), but there was no difference between those living in medium versus low segregation areas. These associations were not mediated by neighborhood poverty or negative income incongruity. These findings suggest variability in the interrelationships between residential segregation and obesity for black and Mexican-American women. PMID:23337312

Do Diabetic Patients Living in Racially Segregated Neighborhoods Experience Different Access and Quality of Care?

PubMed Central

Chan, Kitty S.; Gaskin, Darrell J.; Dinwiddie, Gniesha Y.; McCleary, Rachael

2012-01-01

Background Place of residence, particularly residential segregation, has been implicated in health and health care disparities. However, prior studies have not focused on care for diabetes, a prevalent condition for minority populations. Objective To examine the association of residential segregation with a range of access and quality of care outcomes among Black and Hispanic diabetics using a nationally representative U.S. sample. Research Design Cross-sectional study using data for 1598 adult diabetics from the 2006 Medical Expenditure Panel Survey (MEPS) linked to residential segregation information for Blacks and Hispanics based on the 2000 census. Relationships of five dimensions of residential segregation (dissimilarity, isolation, clustering, concentration and centralization) with access and quality of care outcomes were examined using linear, logistic and multinomial logistic regression models, controlling for respondent characteristics and community utilization and hospital capacity. Results Black and Hispanic diabetics had comparable or better access to providers, but received fewer recommended services. Living in a segregated community was associated with more recommended services received, but also problems with seeing a specialist. The relationship of residential segregation to diabetes care varied depending on type of segregation and race/ethnic group assessed. Conclusions Residential segregation influences the care experience of diabetics in the U.S. Our study highlights the importance of investigating how different types of segregation may affect diabetes care received by patients from different race and ethnic groups. PMID:22525608

Residential segregation and the survival of U.S. urban public hospitals.

PubMed

Ko, Michelle; Needleman, Jack; Derose, Kathryn Pitkin; Laugesen, Miriam J; Ponce, Ninez A

2014-06-01

Residential segregation is associated geographic disparities in access to care, but its impact on local health care policy, including public hospitals, is unknown. We examined the effects of racial residential segregation on U.S. urban public hospital closures from 1987 to 2007, controlling for hospital, market, and policy characteristics. We found that a high level of residential segregation moderated the protective effects of Black population composition, such that a high level of residential segregation, in combination with a high percentage of poor residents, conferred a higher likelihood of hospital closure. More segregated and poorer communities face disadvantages in access to care that may be compounded as a result of instability in the health care safety net. Policy makers should consider the influence of social factors such as residential segregation on the allocation of the safety net resources.

46 CFR 148.155 - Stowage and segregation for potentially dangerous materials.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Stowage and segregation for potentially dangerous...) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.155 Stowage and segregation for potentially dangerous materials. (a) A PDM must be stowed and...

46 CFR 148.155 - Stowage and segregation for potentially dangerous materials.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Stowage and segregation for potentially dangerous...) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.155 Stowage and segregation for potentially dangerous materials. (a) A PDM must be stowed and...

46 CFR 148.155 - Stowage and segregation for potentially dangerous materials.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Stowage and segregation for potentially dangerous...) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.155 Stowage and segregation for potentially dangerous materials. (a) A PDM must be stowed and...

43 CFR 2440.4 - Specific criteria for segregative effect of classification for disposal.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of classification for disposal. 2440.4 Section 2440.4 Public Lands: Interior Regulations Relating to... (2000) SEGREGATION BY CLASSIFICATION Criteria for Segregation § 2440.4 Specific criteria for segregative effect of classification for disposal. Public lands classified or proposed to be classified for disposal...

43 CFR 2440.3 - Specific criteria for segregative effect of classification for retention.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of classification for retention. 2440.3 Section 2440.3 Public Lands: Interior Regulations Relating to... (2000) SEGREGATION BY CLASSIFICATION Criteria for Segregation § 2440.3 Specific criteria for segregative effect of classification for retention. (a) Public lands classified or proposed to be classified for...

36 CFR 254.6 - Segregative effect.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Segregative effect. 254.6... ADJUSTMENTS Land Exchanges § 254.6 Segregative effect. (a) If a proposal is made to exchange Federal lands... segregative effect terminates as follows: (1) Automatically, upon issuance of a patent or other document of...

50 Years after "Brown": Segregation in the Miami-Dade County Public Schools

ERIC Educational Resources Information Center

Moore, James

2004-01-01

Fifty years after the "Brown v. Board of Education" decision outlawed de jure segregation in American schools, many school districts remain segregated. Despite numerous efforts aimed at desegregation, residential segregation--the primary barrier to significant school desegregation--remains entrenched throughout the United States. The Miami-Dade…

Neighborhood Residential Segregation and Physical Health among Hispanic Americans: Good, Bad, or Benign?

ERIC Educational Resources Information Center

Lee, Min-Ah; Ferraro, Kenneth F.

2007-01-01

Although considerable evidence shows that residential segregation is deleterious to the health of African Americans, findings regarding segregation and health for Hispanic Americans are inconsistent. Competing hypotheses regarding the effects of neighborhood segregation on health are tested with data from Puerto Rican and Mexican American…

Development of a test to measure the tendency for a hot-mix asphalt to segregate

DOT National Transportation Integrated Search

2000-02-01

Hot Mix Asphalt tends to segregate during handling and placement. The use of a test to determine the tendency to segregate would assist the user in determining when a mix gradation needs adjustment to avoid construction of a segregated pavement or wh...

76 FR 76180 - Notice of Realty Action: Termination of Segregation, Opening of Public Lands; Montana

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-06

...] Notice of Realty Action: Termination of Segregation, Opening of Public Lands; Montana AGENCY: Bureau of... generally, subject to valid existing rights, the provisions of existing withdrawals, other segregations of..., subject to valid existing rights, the provision of existing withdrawals, other segregations of record, and...

Student Mobility, Segregation, and Achievement Gaps: Evidence from Clark County, Nevada

ERIC Educational Resources Information Center

Welsh, Richard O.

2018-01-01

Student mobility and school segregation are two important issues with significant equity implications for urban school districts that are often addressed separately. This article examines the relationship between student mobility and school segregation. The findings indicate that more segregated schools typically have smaller within-school…

78 FR 4365 - Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major Security...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-22

... 3235-AL12 Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major... public comment to establish capital, margin, and segregation requirements for security-based swap dealers... soliciting comment on proposed rules and rule amendments establishing capital, margin, and segregation...

46 CFR 148.155 - Stowage and segregation for potentially dangerous materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for potentially dangerous...) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.155 Stowage and segregation for potentially dangerous materials. (a) A PDM must be stowed and...

Indian Residential Segregation in the Urban Southwest: 1970 and 1980.

ERIC Educational Resources Information Center

Bohland, James R.

1982-01-01

Indian segregation in 11 cities in the Southwest in 1970 and 1980 was less than the segregation of either Blacks or Spanish Americans. Indian segregation declined between 1970 and 1980, but the decline was least in cities experiencing the greatest growth in Indian population. (Author/AM)

Assembling the bacterial segrosome.

PubMed

Hayes, Finbarr; Barillà, Daniela

2006-05-01

Genome segregation in prokaryotes is a highly ordered process that integrates with DNA replication, cytokinesis and other fundamental facets of the bacterial cell cycle. The segrosome is the nucleoprotein complex that mediates DNA segregation in bacteria, its assembly and organization is best understood for plasmid partition. The recent elucidation of structures of the ParB plasmid segregation protein bound to centromeric DNA, and of the tertiary structures of other segregation proteins, are key milestones in the path to deciphering the molecular basis of bacterial DNA segregation.

Residential segregation and birth weight among racial and ethnic minorities in the United States.

PubMed

Walton, Emily

2009-12-01

Racial and ethnic minorities are often residentially segregated from whites in urban settings, a fact which has important health consequences. Research on the relationship between residential segregation and health outcomes lacks national-level investigation of racial and ethnic minority groups other than African Americans. I use multilevel analyses to examine the associations of residential isolation and clustering with birth weight among Asian, black, and Latino Americans using data from the National Center for Health Statistics' Natality Files and the U.S. Census. Findings indicate that segregation has a negative effect on the likelihood of having a low birth weight baby among Asian Americans, suggesting a possible concentration of social and structural resources in highly-segregated communities. On the contrary, segregation marginally increases the odds of low birth weight among African Americans, but only in the presence of higher poverty rates. Segregation does not affect birth weight among Latino Americans.

Framing Hostilities: Analysis of Mission Statements from Segregated Chicana/o Schools

ERIC Educational Resources Information Center

Orozco, Richard

2012-01-01

This study examined discourses used in mission statements from segregated Chicana/o and White schools. The words and phrases used in segregated Chicana/o school mission statements produce negatively oriented frames that make transparent low expectations and negative attitudes compared to those used in segregated White schools. These frames become…

"E Pluribus"... Separation: Deepening Double Segregation for More Students

ERIC Educational Resources Information Center

Orfield, Gary; Kucsera, John; Siegel-Hawley, Genevieve

2012-01-01

This report shows segregation has increased dramatically across the country for Latino students, who are attending more intensely segregated and impoverished schools than they have for generations. The segregation increases have been the most dramatic in the West. The typical Latino student in the region attends a school where less than a quarter…

43 CFR 2091.7-2 - Segregative effect and opening: Taylor Grazing Act.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregative effect and opening: Taylor Grazing Act. 2091.7-2 Section 2091.7-2 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.7-2 Segregative effect and opening: Taylor...

43 CFR 2091.7-1 - Segregative effect and opening: Classifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: Classifications. 2091.7-1 Section 2091.7-1 Public Lands: Interior Regulations Relating to Public Lands (Continued... RULES Segregation and Opening of Lands § 2091.7-1 Segregative effect and opening: Classifications. (a)(1... authority of the Classification and Multiple Use Act (43 U.S.C. 1411-18) are segregated to the extent...

Aversive Racism and Intergroup Contact Theories: Cultural Competence in a Segregated World

ERIC Educational Resources Information Center

Rodenborg, Nancy A.; Boisen, Laura A.

2013-01-01

The United States remains highly segregated, and social work students are likely to live and work in segregated contexts. What implications does this have for their cultural competence? Does segregation affect social workers' ability to serve diverse clients without bias? This article reviews two social psychology theories, aversive racism…

Relationship between School and Residential Segregation at the Turn of the Century.

ERIC Educational Resources Information Center

Rickles, Jordan; Ong, Paul M.

This paper examines the relationship between school and residential segregation, noting that while these two forms of segregation are fundamentally linked, other factors cause them to diverge. The analysis focuses on segregation in 329 metropolitan areas. Data come from the 1998-99 National Center for Education Statistics Common Core of Data…

46 CFR 154.300 - Segregation of hold spaces from other spaces.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Segregation of hold spaces from other spaces. 154.300... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must be segregated from machinery and boiler spaces, accommodation, service and control spaces, chain lockers...

46 CFR 154.300 - Segregation of hold spaces from other spaces.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Segregation of hold spaces from other spaces. 154.300... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must be segregated from machinery and boiler spaces, accommodation, service and control spaces, chain lockers...

46 CFR 154.300 - Segregation of hold spaces from other spaces.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Segregation of hold spaces from other spaces. 154.300... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must be segregated from machinery and boiler spaces, accommodation, service and control spaces, chain lockers...

46 CFR 154.300 - Segregation of hold spaces from other spaces.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Segregation of hold spaces from other spaces. 154.300... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must be segregated from machinery and boiler spaces, accommodation, service and control spaces, chain lockers...

46 CFR 154.300 - Segregation of hold spaces from other spaces.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Segregation of hold spaces from other spaces. 154.300... Equipment Ship Arrangements § 154.300 Segregation of hold spaces from other spaces. Hold spaces must be segregated from machinery and boiler spaces, accommodation, service and control spaces, chain lockers...

43 CFR 3210.10 - When does lease segregation occur?

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false When does lease segregation occur? 3210.10 Section 3210.10 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND... Lease Information § 3210.10 When does lease segregation occur? (a) Lease segregation occurs when: (1) A...

Are We Segregated and Satisfied? Segregation and Inequality in Southern California Schools

ERIC Educational Resources Information Center

Kucsera, John V.; Siegel-Hawley, Genevieve; Orfield, Gary

2015-01-01

Southern California is facing a demographic transformation that will become characteristic of the nation as a whole in coming decades. In this research, we present a historical review of the region's attempt to address school inequity, recent enrollment and segregation trends, and an investigation of whether segregation still matters. Our results…

17 CFR 31.7 - Maintenance of minimum financial, cover and segregation requirements by leverage transaction...

Code of Federal Regulations, 2010 CFR

2010-04-01

... financial, cover and segregation requirements by leverage transaction merchants. 31.7 Section 31.7 Commodity... of minimum financial, cover and segregation requirements by leverage transaction merchants. (a) Each... required by § 31.8, or that the amount of leverage customer funds in segregation is less than is required...

43 CFR 2611.2 - Period of segregation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Period of segregation. 2611.2 Section 2611..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) CAREY ACT GRANTS Segregation Under the Carey Act: Procedures § 2611.2 Period of segregation. (a) The States are allowed 10 years from the date of the signing...

28 CFR 540.16 - Inmate correspondence while in segregation and holdover status.

Code of Federal Regulations, 2010 CFR

2010-07-01

... segregation and holdover status. 540.16 Section 540.16 Judicial Administration BUREAU OF PRISONS, DEPARTMENT... Inmate correspondence while in segregation and holdover status. (a) The Warden shall permit an inmate in... those of other inmates insofar as practical. (b) The Warden shall permit an inmate in segregation to...

28 CFR 540.16 - Inmate correspondence while in segregation and holdover status.

Code of Federal Regulations, 2011 CFR

2011-07-01

... segregation and holdover status. 540.16 Section 540.16 Judicial Administration BUREAU OF PRISONS, DEPARTMENT... Inmate correspondence while in segregation and holdover status. (a) The Warden shall permit an inmate in... those of other inmates insofar as practical. (b) The Warden shall permit an inmate in segregation to...

43 CFR 2091.9 - Segregation and opening resulting from laws specific to Alaska.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening resulting from laws specific to Alaska. 2091.9 Section 2091.9 Public Lands: Interior Regulations Relating to Public...) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.9 Segregation and opening resulting from...

17 CFR 31.7 - Maintenance of minimum financial, cover and segregation requirements by leverage transaction...

Code of Federal Regulations, 2011 CFR

2011-04-01

... financial, cover and segregation requirements by leverage transaction merchants. 31.7 Section 31.7 Commodity... of minimum financial, cover and segregation requirements by leverage transaction merchants. (a) Each... required by § 31.8, or that the amount of leverage customer funds in segregation is less than is required...

43 CFR 2091.2-1 - Segregation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation. 2091.2-1 Section 2091.2-1..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.2-1 Segregation. The publication of a Notice of Realty Action in the Federal Register...

43 CFR 3873.1 - Segregation of mineral from non-mineral land.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Segregation of mineral from non-mineral...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS AND CONFLICTS Segregation § 3873.1 Segregation of mineral from non-mineral land. Where a survey is...

43 CFR 3873.1 - Segregation of mineral from non-mineral land.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Segregation of mineral from non-mineral...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS AND CONFLICTS Segregation § 3873.1 Segregation of mineral from non-mineral land. Where a survey is...

43 CFR 3873.1 - Segregation of mineral from non-mineral land.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Segregation of mineral from non-mineral...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) ADVERSE CLAIMS, PROTESTS AND CONFLICTS Segregation § 3873.1 Segregation of mineral from non-mineral land. Where a survey is...

Ionic Segregation on Grain Boundaries in Thermally Grown Alumina Scales

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

Pint, Bruce A; Unocic, Kinga A

2012-01-01

This study first examined segregation behaviour in the alumina scale formed after 100 h at 1100 C on bare and MCrAlYHfSi-coated single-crystal superalloys with {approx}10 ppma La and Y. For the bare superalloy, Hf and Ti were detected on the grain boundaries of the inner columnar alumina layer. Increasing the oxidation temperature to 1200 C for 2 h did not change the segregation behavior. With the bond coating, both Y and Hf were segregated to the grain boundaries as expected. However, there was evidence of Ti-rich oxide particles near the gas interface suggesting that Ti diffused from the superalloy throughmore » the coating. To further understand these segregation observations with multiple dopants, other alumina-forming systems were examined. Alumina scale grain boundary co-segregation of Ti with Y is common for FeCrAl alloys. Co-segregation of Hf and Ti was observed in the scale formed on co-doped NiAl. No La segregation was detected in the scale formed on NiCrAl with only a 19 ppma La addition, however, the scale was adherent.« less

Segregation simulation of binary granular matter under horizontal pendulum vibrations

NASA Astrophysics Data System (ADS)

Ma, Xuedong; Zhang, Yanbing; Ran, Heli; Zhang, Qingying

2016-08-01

Segregation of binary granular matter with different densities under horizontal pendulum vibrations was investigated through numerical simulation using a 3D discrete element method (DEM). The particle segregation mechanism was theoretically analyzed using gap filling, momentum and kinetic energy. The effect of vibrator geometry on granular segregation was determined using the Lacey mixing index. This study shows that dynamic changes in particle gaps under periodic horizontal pendulum vibrations create a premise for particle segregation. The momentum of heavy particles is higher than that of light particles, which causes heavy particles to sink and light particles to float. With the same horizontal vibration parameters, segregation efficiency and stability, which are affected by the vibrator with a cylindrical convex geometry, are superior to that of the original vibrator and the vibrator with a cross-bar structure. Moreover, vibrator geometry influences the segregation speed of granular matter. Simulation results of granular segregation by using the DEM are consistent with the final experimental results, thereby confirming the accuracy of the simulation results and the reliability of the analysis.

More reliable inference for the dissimilarity index of segregation

PubMed Central

Allen, Rebecca; Burgess, Simon; Davidson, Russell; Windmeijer, Frank

2015-01-01

Summary The most widely used measure of segregation is the so‐called dissimilarity index. It is now well understood that this measure also reflects randomness in the allocation of individuals to units (i.e. it measures deviations from evenness, not deviations from randomness). This leads to potentially large values of the segregation index when unit sizes and/or minority proportions are small, even if there is no underlying systematic segregation. Our response to this is to produce adjustments to the index, based on an underlying statistical model. We specify the assignment problem in a very general way, with differences in conditional assignment probabilities underlying the resulting segregation. From this, we derive a likelihood ratio test for the presence of any systematic segregation, and bias adjustments to the dissimilarity index. We further develop the asymptotic distribution theory for testing hypotheses concerning the magnitude of the segregation index and show that the use of bootstrap methods can improve the size and power properties of test procedures considerably. We illustrate these methods by comparing dissimilarity indices across school districts in England to measure social segregation. PMID:27774035

Study of the Formation Mechanism of A-Segregation Based on Microstructural Morphology

NASA Astrophysics Data System (ADS)

Zhang, Zhao; Bao, Yuchong; Liu, Lin; Pian, Song; Li, Ri

2018-04-01

A model that combines a cellular automaton (CA) and lattice Boltzmann method (LBM) is presented. The mechanism of A-segregation in an Fe-0.34 wt pct C alloy ingot is analyzed on the basis of microstructural morphology calculations. The CA is used to capture the solid/liquid interface, while the LBM is used to calculate the transport phenomena. (1) The solidification of global columnar dendrites was simulated, and two obvious A-segregation bands appeared in the middle-radius region between the ingot wall surface and the centerline. In addition, the angle of deflection to the centerline increased with the increasing heat dissipation rate of the wall surface. When natural convection was ignored, the A-segregation disappeared, and only positive segregation was present in the center and bottom corner of the ingot. (2) Mixed columnar-equiaxed solidification was simulated. Many A-segregation bands appeared in the ingot. (3) Global equiaxed solidification was simulated, and no A-segregation bands were found. The results show that the upward movement of the high-concentration melt is the key to the formation of A-segregation bands, and remelting and the emergence of equiaxed grains are not necessary conditions to develop these bands. However, the appearance of equiaxed grains accelerates the formation of vortexes; thus, many A-segregation bands appear during columnar-equiaxed solidification.

Mechanisms of time-based figure-ground segregation.

PubMed

Kandil, Farid I; Fahle, Manfred

2003-11-01

Figure-ground segregation can rely on purely temporal information, that is, on short temporal delays between positional changes of elements in figure and ground (Kandil, F.I. & Fahle, M. (2001) Eur. J. Neurosci., 13, 2004-2008). Here, we investigate the underlying mechanisms by measuring temporal segregation thresholds for various kinds of motion cues. Segregation can rely on monocular first-order motion (based on luminance modulation) and second-order motion cues (contrast modulation) with a high temporal resolution of approximately 20 ms. The mechanism can also use isoluminant motion with a reduced temporal resolution of 60 ms. Figure-ground segregation can be achieved even at presentation frequencies too high for human subjects to inspect successive frames individually. In contrast, when stimuli are presented dichoptically, i.e. separately to both eyes, subjects are unable to perceive any segregation, irrespective of temporal frequency. We propose that segregation in these displays is detected by a mechanism consisting of at least two stages. On the first level, standard motion or flicker detectors signal local positional changes (flips). On the second level, a segregation mechanism combines the local activities of the low-level detectors with high temporal precision. Our findings suggest that the segregation mechanism can rely on monocular detectors but not on binocular mechanisms. Moreover, the results oppose the idea that segregation in these displays is achieved by motion detectors of a higher order (motion-from-motion), but favour mechanisms sensitive to short temporal delays even without activation of higher-order motion detectors.

Evolutionary dynamics of adult stem cells: comparison of random and immortal-strand segregation mechanisms.

PubMed

Tannenbaum, Emmanuel; Sherley, James L; Shakhnovich, Eugene I

2005-04-01

This paper develops a point-mutation model describing the evolutionary dynamics of a population of adult stem cells. Such a model may prove useful for quantitative studies of tissue aging and the emergence of cancer. We consider two modes of chromosome segregation: (1) random segregation, where the daughter chromosomes of a given parent chromosome segregate randomly into the stem cell and its differentiating sister cell and (2) "immortal DNA strand" co-segregation, for which the stem cell retains the daughter chromosomes with the oldest parent strands. Immortal strand co-segregation is a mechanism, originally proposed by [Cairns Nature (London) 255, 197 (1975)], by which stem cells preserve the integrity of their genomes. For random segregation, we develop an ordered strand pair formulation of the dynamics, analogous to the ordered strand pair formalism developed for quasispecies dynamics involving semiconservative replication with imperfect lesion repair (in this context, lesion repair is taken to mean repair of postreplication base-pair mismatches). Interestingly, a similar formulation is possible with immortal strand co-segregation, despite the fact that this segregation mechanism is age dependent. From our model we are able to mathematically show that, when lesion repair is imperfect, then immortal strand co-segregation leads to better preservation of the stem cell lineage than random chromosome segregation. Furthermore, our model allows us to estimate the optimal lesion repair efficiency for preserving an adult stem cell population for a given period of time. For human stem cells, we obtain that mispaired bases still present after replication and cell division should be left untouched, to avoid potentially fixing a mutation in both DNA strands.

Evolutionary dynamics of adult stem cells: Comparison of random and immortal-strand segregation mechanisms

NASA Astrophysics Data System (ADS)

Tannenbaum, Emmanuel; Sherley, James L.; Shakhnovich, Eugene I.

2005-04-01

This paper develops a point-mutation model describing the evolutionary dynamics of a population of adult stem cells. Such a model may prove useful for quantitative studies of tissue aging and the emergence of cancer. We consider two modes of chromosome segregation: (1) random segregation, where the daughter chromosomes of a given parent chromosome segregate randomly into the stem cell and its differentiating sister cell and (2) “immortal DNA strand” co-segregation, for which the stem cell retains the daughter chromosomes with the oldest parent strands. Immortal strand co-segregation is a mechanism, originally proposed by [Cairns Nature (London) 255, 197 (1975)], by which stem cells preserve the integrity of their genomes. For random segregation, we develop an ordered strand pair formulation of the dynamics, analogous to the ordered strand pair formalism developed for quasispecies dynamics involving semiconservative replication with imperfect lesion repair (in this context, lesion repair is taken to mean repair of postreplication base-pair mismatches). Interestingly, a similar formulation is possible with immortal strand co-segregation, despite the fact that this segregation mechanism is age dependent. From our model we are able to mathematically show that, when lesion repair is imperfect, then immortal strand co-segregation leads to better preservation of the stem cell lineage than random chromosome segregation. Furthermore, our model allows us to estimate the optimal lesion repair efficiency for preserving an adult stem cell population for a given period of time. For human stem cells, we obtain that mispaired bases still present after replication and cell division should be left untouched, to avoid potentially fixing a mutation in both DNA strands.

The effect of segregation on the austemper transformation and toughness of ductile irons

NASA Astrophysics Data System (ADS)

Lin, B. Y.; Chen, E. T.; Lei, T. S.

1998-06-01

The effect of segregation of alloying elements on the phase transformation of ductile iron during austempering was investigated. Four heats, each containing 0.4%Mn, 1% Cu, 1.5% Ni, or 0.4% Mo (wt%) separately, were melted; then three different sizes of casting bars (3,15, and 75 mm diameter) were poured from each heat. The distribution and the degree of segregation of certain elements were quantitatively analyzed using an electron microprobe. A personal computer (PC)-controlled heat treating system was used to measure electrical resistivity, and the information on resistivity variations was used to analyze the effect of segregation on phase transformations during austempering. Also, Charpy impact and Rockwell hardness tests were performed to determine the effect of segregation on properties. Results of the electron microprobe analysis showed that the degree of segregation of alloy elements increases with an increase in diameter of the casting bars (i.e., an increase of solidification time of castings). The degree of segregation of alloy elements, represented by segregation ratio (SR) (the maximum concentration of element in cell divided by the minimum concentration of element in cell), varied linearly with the casting modulus (M) (volume of casting divided by surface area of casting). Regarding the segregating tendency among alloy elements, positive segregating elements Mn and Mo showed more segregation than the negative segregating elements Si, Cu, and Ni. In addition, segregation of Mo was more significant than Mn, and that for Cu was greater than Ni and Si. Between the time of finishing the first stage and beginning the second stage of bainite reaction in ductile irons, there is a significant “processing window,” At;, for austempering to obtain optimum mechanical properties. From the electrical resistivity data, it was observed that the austempering temperature plays a major role in the processing window. There was a narrow window at 400 ‡C but a larger one at 350 ‡C. Additionally, the microsegregation of alloying elements led to variation of the time of phase transformation for various regions in the grain cells of ductile iron which caused the processing window to decrease. The span of the processing window decreased with an increase in degree of segregation. There was no significant difference in the hardness of the alloys in various diameter specimens. However, the impact toughness was significantly affected by the segregation. The impact values in 15 mm specimens with less degree of segregation were greater than those in 75 mm specimens with significant segregation. The Ni, Cu, and Mn alloys that were austempered to complete the first stage of bainite formation had approximately the same impact values for all diameter samples. The Mo alloy upon austempering produced no bainite, but it had much untransformed retained austenite in the intercellular regions and, therefore, had lower impact values.

Segregation Levels in Cleveland Public Schools and the Cleveland Voucher Program. School Choice Issues in the State

ERIC Educational Resources Information Center

Forster, Greg

2006-01-01

Examining the widespread claims that private schools have high segregation levels and vouchers will lead to greater segregation, this study finds that both assertions are empirically unsupportable. Private schools participating in Cleveland's voucher program are much less segregated than Cleveland's public schools. This means that students using…

The Big Disconnect between Segregation and Integration

ERIC Educational Resources Information Center

Verdun, Vincene

2005-01-01

The hearts and minds of the American people have been won over on the issue of segregation. However, the dilemma is that while an overwhelming majority of Americans would cringe at the idea of a racially segregated America, America remains racially segregated and racial equality is more ideal than real. Even though there is almost no legal…

Racial Segregation and Educational Outcomes in Metropolitan Boston. Metro Boston Equity Initiative. Issue Summary No.6

ERIC Educational Resources Information Center

Lee, Chungmei

2004-01-01

This report takes a look at the issues concerning racial segregation and educational outcomes in Metropolitan Boston. Despite the fact that metro Boston is overwhelmingly white, its public schools are highly segregated by race and language. Segregated minority schools in metro Boston are profoundly unequal, with high poverty levels, with lower…

43 CFR 2091.5-4 - Segregative effect and opening: Water power withdrawals.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Segregative effect and opening: Water power withdrawals. 2091.5-4 Section 2091.5-4 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.5-4 Segregative effect and opening: Water power...

43 CFR 2091.5-4 - Segregative effect and opening: Water power withdrawals.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Segregative effect and opening: Water power withdrawals. 2091.5-4 Section 2091.5-4 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.5-4 Segregative effect and opening: Water power...

43 CFR 2091.5-4 - Segregative effect and opening: Water power withdrawals.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Segregative effect and opening: Water power withdrawals. 2091.5-4 Section 2091.5-4 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.5-4 Segregative effect and opening: Water power...

Gender Segregation in Nursery School: Predictors and Outcomes.

ERIC Educational Resources Information Center

Maccoby, Eleanor E.; Jacklin, Carol Nagy

Sex segregation is a powerful phenomenon in childhood. It occurs universally whenever children have a choice of playmates and is found in sub-human primates too. Adults are not directly responsible for sex segregation. Data do not support the hypothesis that the most ladylike girls and the most rough and active boys first form the segregated play…

Segregation, Desegregation, Segregation: Charter School Options as a Return to Separate and Unequal Schools for Urban Families

ERIC Educational Resources Information Center

Chapman, Thandeka K.

2018-01-01

The controversial glory of the "Brown" decisions and the retraction of court-ordered reforms represent the limited gains of racial justice in education and the protection of white privilege through law and policy. The return to segregation, as propagated through the rise of racially and economically segregated charter schools, exhibits…

75 FR 444 - Notice of Realty Action: Direct Sale of Public Lands in Tehama County, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-05

... segregated from appropriation under the public land laws, including the mining laws. The segregation terminates upon issuance of a patent, publication in the Federal Register of a termination of the segregation, or 2 years from the date of segregation, whichever occurs first. The lands will not be sold until at...

43 CFR 2091.7 - Segregation and opening of lands classified for a specific use.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening of lands classified for a specific use. 2091.7 Section 2091.7 Public Lands: Interior Regulations Relating to Public...) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.7 Segregation and opening of lands...

43 CFR 2091.2 - Segregation and opening resulting from publication of a Notice of Realty Action.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening resulting from publication of a Notice of Realty Action. 2091.2 Section 2091.2 Public Lands: Interior Regulations Relating to... (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.2 Segregation and opening...

43 CFR 2091.4-2 - Segregation and opening: Airport leases and grants.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening: Airport leases and grants. 2091.4-2 Section 2091.4-2 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.4-2 Segregation and opening: Airport leases and...

77 FR 71568 - Capital, Margin, and Segregation Requirements for Security-Based Swap Dealers and Major Security...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-03

... [Release No. 34-68071A; File No. S7-08-12] RIN 3235-AL12 Capital, Margin, and Segregation Requirements for... participants (``MSBSPs''), segregation requirements for SBSDs, and notification requirements with respect to segregation for SBSDs and MSBSPs, as well as increases to the minimum net capital requirements for broker...

The Complex Determinants of School Intake Characteristics and Segregation, England 1989 to 2014

ERIC Educational Resources Information Center

Gorard, Stephen

2016-01-01

The extent of between-school segregation, or clustering of disadvantaged students within schools, in England varies depending on the indicator of interest. For example, the trend over time for segregation by student poverty differs from those for ethnicity or special educational need. Additionally the causes of the level of segregation for any…

43 CFR 2091.4-3 - Segregation and opening: Carey Act.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening: Carey Act. 2091.4-3 Section 2091.4-3 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF... Segregation and Opening of Lands § 2091.4-3 Segregation and opening: Carey Act. (a) For lands covered by a...

43 CFR 2091.4-1 - Segregation and opening: Desert-land entries and Indian allotments.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening: Desert-land entries and Indian allotments. 2091.4-1 Section 2091.4-1 Public Lands: Interior Regulations Relating to... (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.4-1 Segregation and opening...

46 CFR 148.145 - Stowage and segregation for materials of Class 7.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for materials of Class 7. 148... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.145 Stowage and segregation for materials of Class 7. (a) Class 7 material listed in Table 148.10 of this part...

43 CFR 3107.3-2 - Segregation of leases committed in part.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation of leases committed in part... Continuation, Extension or Renewal § 3107.3-2 Segregation of leases committed in part. Any lease committed... term of the lease or for 2 years from the date of segregation, whichever is longer. However, for any...

43 CFR 2091.3 - Segregation and opening resulting from a proposal or application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening resulting from a proposal or application. 2091.3 Section 2091.3 Public Lands: Interior Regulations Relating to Public Lands... LAWS AND RULES Segregation and Opening of Lands § 2091.3 Segregation and opening resulting from a...

43 CFR 2091.4-2 - Segregation and opening: Airport leases and grants.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Segregation and opening: Airport leases... LAWS AND RULES Segregation and Opening of Lands § 2091.4-2 Segregation and opening: Airport leases and grants. (a) The issuance of a lease for airport purposes under the authority of the Act of May 24, 1928...

43 CFR 2091.4-2 - Segregation and opening: Airport leases and grants.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Segregation and opening: Airport leases... LAWS AND RULES Segregation and Opening of Lands § 2091.4-2 Segregation and opening: Airport leases and grants. (a) The issuance of a lease for airport purposes under the authority of the Act of May 24, 1928...

43 CFR 2091.4-2 - Segregation and opening: Airport leases and grants.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Segregation and opening: Airport leases... LAWS AND RULES Segregation and Opening of Lands § 2091.4-2 Segregation and opening: Airport leases and grants. (a) The issuance of a lease for airport purposes under the authority of the Act of May 24, 1928...

Post-Slavery? Post-Segregation? Post-Racial? A History of the Impact of Slavery, Segregation, and Racism on the Education of African Americans

ERIC Educational Resources Information Center

Span, Christopher M.

2015-01-01

This chapter details how slavery, segregation, and racism impacted the educational experiences of African Americans from the colonial era to the present. It argues that America has yet to be a truly post-slavery and post-segregation society, let alone a post-racial society.

Residential segregation, health behavior and overweight/obesity among a national sample of African American adults.

PubMed

Corral, Irma; Landrine, Hope; Hao, Yongping; Zhao, Luhua; Mellerson, Jenelle L; Cooper, Dexter L

2012-04-01

We examined the role of residential segregation in 5+ daily fruit/vegetable consumption, exercise, and overweight/obesity among African Americans by linking data on the 11,142 African American adults in the 2000 Behavioral Risk Factor Surveillance System to 2000 census data on the segregation of metropolitan statistical areas (MSAs). Multi-level modeling revealed that after controlling for individual-level variables, MSA Segregation and Poverty contributed to fruit/vegetable consumption, MSA Poverty alone contributed to exercise, and MSA Segregation alone contributed to overweight/obesity. These findings highlight the need for research on the built-environments of the segregated neighborhoods in which most African Americans reside, and suggest that neighborhood disparities may contribute to health disparities.

The Effect of Strict Segregation on Pseudomonas aeruginosa in Cystic Fibrosis Patients

PubMed Central

van Mansfeld, Rosa; de Vrankrijker, Angelica; Brimicombe, Roland; Heijerman, Harry; Teding van Berkhout, Ferdinand; Spitoni, Cristian; Grave, Sanne; van der Ent, Cornelis; Wolfs, Tom; Willems, Rob; Bonten, Marc

2016-01-01

Introduction Segregation of patients with cystic fibrosis (CF) was implemented to prevent chronic infection with epidemic Pseudomonas aeruginosa strains with presumed detrimental clinical effects, but its effectiveness has not been carefully evaluated. Methods The effect of strict segregation on the incidence of P. aeruginosa infection in CF patients was investigated through longitudinal protocolized follow-up of respiratory tract infection before and after segregation. In two nested cross-sectional studies in 2007 and 2011 the P. aeruginosa population structure was investigated and clinical parameters were determined in patients with and without infection with the Dutch epidemic P. aeruginosa clone (ST406). Results Of 784 included patients 315 and 382 were at risk for acquiring chronic P. aeruginosa infection before and after segregation. Acquisition rates were, respectively, 0.14 and 0.05 per 1,000 days at risk (HR: 0.66, 95% CI [0.2548–1.541]; p = 0.28). An exploratory subgroup analysis indicated lower acquisition after segregation in children < 15 years of age (HR: 0.43, 95% CI[0.21–0.95]; p = 0.04). P. aeruginosa population structure did not change after segregation and ST406 was not associated with lung function decline, death or lung transplantation. Conclusions Strict segregation was not associated with a statistically significant lower acquisition of chronic P. aeruginosa infection and ST406 was not associated with adverse clinical outcome. After segregation there were no new acquisitions of ST406. In an unplanned exploratory analysis chronic acquisition of P. aeruginosa was lower after implementation of segregation in patients under 15 years of age. PMID:27280467

Racial/ethnic residential segregation, neighborhood poverty and urinary biomarkers of diet in New York City adults.

PubMed

Yi, Stella S; Ruff, Ryan R; Jung, Molly; Waddell, Elizabeth Needham

2014-12-01

Consuming less sodium and more potassium are components of a healthy diet and reduced cardiovascular disease risk. Racial/ethnic segregation and poverty are both associated with dietary habits, but data linking dietary intake to neighborhood characteristics are limited, particularly in Hispanic and Asian American ethnic enclaves. This study presents relationships between neighborhood-level segregation, poverty and biologic indicators of sodium and potassium consumption. Data were from the 2010 Heart Follow-Up Study, a cross-sectional health survey, which included 24-h urine collections and self-reported health status (n = 1656). Black, Hispanic, and Asian segregated areas and neighborhood poverty were defined for aggregated zip-code areas. Multivariable models assessed the association between neighborhood segregation and poverty and sodium and potassium intake, after adjustment for individual-level covariates. In unadjusted models, potassium intake (a marker of fruit and vegetable consumption) was lower in high-versus low-Hispanic segregated neighborhoods, and the sodium-potassium ratio was higher in high-versus low black and Hispanic segregated neighborhoods, and in high-versus low-poverty neighborhoods; the sodium-potassium ratio was lower in high-versus low Asian segregated neighborhoods. Segregation and poverty were not independently associated with nutrition biomarkers after adjustment for demographics and for each other; however, practical consideration of neighborhood race/ethnic composition may be useful to understand differences in consumption. Copyright © 2014 Elsevier Ltd. All rights reserved.

Do Strict Land Use Regulations Make Metropolitan Areas More Segregated by Income?

PubMed Central

Lens, Michael C.; Monkkonen, Paavo

2018-01-01

Problem, research strategy, and findings Income segregation has risen in each of the last four decades in U.S. metropolitan areas, which can have lifelong impacts on the health, economic productivity, and behaviors of residents. Although it is widely assumed that local land use regulations—such as minimum lot sizes and growth controls—exclude low-income households from wealthier neighborhoods, the empirical research is surprisingly limited. We examine the relationship between land use regulation and segregation by income using new measures for the 95 biggest cities in the United States. We find that density restrictions are associated with the segregation of the wealthy and middle income, but not the poor. We also find that more local pressure to regulate land use is linked to higher rates of income segregation, but that more state control is connected to lower-income segregation. Takeaway for practice Density restrictions do drive urban income segregation of the rich, not the poor, but should be addressed because rich enclaves create significant metropolitan problems. Planners at the local level need assistance from regional and state efforts to ameliorate income segregation. Inclusionary housing requirements have a greater potential to reduce income segregation than bringing higher-income households into lower-income parts of the city. Finally, comprehensive and consistent data on the impacts of local land use regulations should be collected to inform future research and planning practice. PMID:29422701

Freedom from Racial Barriers: The Empirical Evidence on Vouchers and Segregation. School Choice Issues in Depth

ERIC Educational Resources Information Center

Forster, Greg

2006-01-01

This report collects the results of all available studies using valid empirical methods to compare segregation in public and private schools, both in general and in the context of school voucher programs. Examining the widespread claims that private schools have high segregation levels and vouchers will lead to greater segregation, this report…

Parental Choice in the Netherlands: Growing Concerns about Segregation. Sanford Working Paper Series. SAN10-02

ERIC Educational Resources Information Center

Ladd, Helen F.; Fiske, Edward B.; Ruijs, Nienke

2010-01-01

The Netherlands has a long history of parental choice and school anatomy. This paper examines why segregation by educational disadvantage has only recently emerged as a policy issue in the Netherlands. In addition, we document the levels and trends of school segregation in Dutch cities. We find segregation levels that are high both absolutely and…

The Sense of Place behind Segregating Practices: An Ethnographic Approach to the Symbolic Partitioning of Metro Manila

ERIC Educational Resources Information Center

Garrido, Marco

2013-01-01

The literature on cities in the developing world equates segregation with the proliferation of enclaves and slums and tends to overlook how the people associated with those places are further segregated in public spaces and enclaves. To account for the symbolic partitioning of Metro Manila, I document the segregating practices of the residents of…

46 CFR 148.130 - Stowage and segregation for materials of Class 4.2.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for materials of Class 4.2. 148... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.130 Stowage and segregation for materials of Class 4.2. (a) Class 4.2 materials listed in Table 148.10 of this...

77 FR 7601 - Notice of Segregation of Public Lands for the Pattern Energy Group Ocotillo Express Wind Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-13

... LVRWB10B3980] Notice of Segregation of Public Lands for the Pattern Energy Group Ocotillo Express Wind Energy...) application for the Ocotillo Express Wind Project. The public land contained in this segregation totals approximately 12,436 acres. DATES: Effective Date: This segregation is effective on February 13, 2012. FOR...

46 CFR 148.140 - Stowage and segregation for materials of Class 5.1.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for materials of Class 5.1. 148... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.140 Stowage and segregation for materials of Class 5.1. (a) Class 5.1 materials listed in Table 148.10 of this...

46 CFR 148.135 - Stowage and segregation for materials of Class 4.3.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for materials of Class 4.3. 148... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.135 Stowage and segregation for materials of Class 4.3. (a) Class 4.3 materials listed in Table 148.10 of this...

46 CFR 148.125 - Stowage and segregation for materials of Class 4.1.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Stowage and segregation for materials of Class 4.1. 148... CARGOES CARRIAGE OF BULK SOLID MATERIALS THAT REQUIRE SPECIAL HANDLING Stowage and Segregation § 148.125 Stowage and segregation for materials of Class 4.1. (a) Class 4.1 materials listed in Table 148.10 of this...

43 CFR 2091.4 - Segregation and opening resulting from the allowance of entries, leases, grants or contracts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregation and opening resulting from the allowance of entries, leases, grants or contracts. 2091.4 Section 2091.4 Public Lands: Interior Regulations... MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of Lands § 2091.4 Segregation and opening...

Do Irregularly Shaped School Attendance Zones Contribute to Racial Segregation or Integration?

PubMed Central

Saporito, Salvatore; Van Riper, David

2017-01-01

This research investigates if and how much the shapes of school attendance zones contribute to racial segregation in schools. We find that the typical school attendance zone is relatively compact and resembles a square-like shape. Compact zones typically draw children from local residential areas, and since local areas are often racially homogeneous, this suggests that high levels of racial segregation in the largest school districts are largely structured by existing residential segregation. Still, this study finds that the United States contains some attendance zones with highly irregular shapes—some of which are as irregular as the most irregular Congressional District. Although relatively rare, attendance zones that are highly irregular in shape almost always contain racially diverse student populations. This racial diversity contributes to racial integration within school districts. These findings contradict recent theoretical and empirical scholarship arguing that irregularly shaped zones contribute to racial segregation in schools. Our findings suggest that most racial segregation in school attendance zones is driven by large-scale segregation across residential areas rather than a widespread practice among school districts to exacerbate racial segregation by delineating irregularly shaped attendance zones. PMID:28804732

Life cycle assessment of segregating fattening pig urine and feces compared to conventional liquid manure management.

PubMed

De Vries, Jerke W; Aarnink, André J A; Groot Koerkamp, Peter W G; De Boer, Imke J M

2013-02-05

Gaseous emissions from in-house storage of liquid animal manure remain a major contributor to the environmental impact of manure management. Our aim was to assess the life cycle environmental consequences and reduction potential of segregating fattening pig urine and feces with an innovative V-belt system and to compare it to conventional liquid manure management, that is, the reference. Moreover, we aimed at analyzing the uncertainty of the outcomes related to applied emission factors. We compared a reference with two scenarios: segregation with solid, aerobically, stored feces and with liquid, anaerobically, stored feces. Results showed that, compared to the reference, segregation reduced climate change (CC) up to 82%, due to lower methane emission, reduced terrestrial acidification (TA) and particulate matter formation (PMF) up to 49%, through lower ammonia emission, but increased marine eutrophication up to 11% through nitrogen oxide emission from storage and nitrate leaching after field application. Fossil fuel depletion did not change. Segregation with liquid feces revealed lower environmental impact than segregation with solid feces. Uncertainty analysis supported the conclusion that segregating fattening pig urine and feces significantly reduced CC and additionally segregation with liquid feces significantly reduced TA and PMF compared to the reference.

Segregation in Post-Civil Rights America: Stalled Integration or End of the Segregated Century?

PubMed Central

Massey, Douglas S.; Rugh, Jacob S.

2016-01-01

In this paper we adjudicate between competing claims of persisting segregation and rapid integration by analyzing trends in residential dissimilarity and spatial isolation for African Americans, Hispanics, and Asians living in 287 consistently defined metropolitan areas from 1970 to 2010. On average, black segregation and isolation have fallen steadily but still remain very high in many areas, particularly those areas historically characterized by hypersegregation. In contrast, Hispanic segregation has increased slightly but Hispanic isolation has risen substantially owing to rapid population growth. Asian segregation has changed little and remains moderate, and although Asian isolation has increased it remains at low levels compared with other groups. Multivariate analyses reveal that segregation and isolation are being actively produced in some areas by restrictive density zoning regimes, large and/or rising minority percentages, lagging minority socioeconomic status, and active expressions of anti-black and anti-Latino sentiment, especially in large metropolitan areas. Areas displaying these characteristics are either integrating very slowly (in the case of blacks) or becoming more segregated (in the case of Hispanics), whereas those lacking these attributes are clearly moving toward integration, often quite rapidly. PMID:26966459

Morphology and luminosity segregation of galaxies in nearby loose groups

NASA Astrophysics Data System (ADS)

Girardi, M.; Rigoni, E.; Mardirossian, F.; Mezzetti, M.

2003-08-01

We study morphology and luminosity segregation of galaxies in loose groups. We analyze the two catalogs of groups identified in the Nearby Optical Galaxy (NOG) sample, by means of hierarchical and percolation ``friends-of-friends'' methods (HG and PG catalogs, respectively). In the first part of our analysis we consider 387 and 436 groups of HG and PG and compare morphology- (luminosity-) weighted to unweighted group properties: velocity dispersion, mean pairwise distance, and mean groupcentric distance of member galaxies. The second part of our analysis is based on two ensemble systems, one for each catalog, built by suitably combining together galaxies of all groups (1584 and 1882 galaxies for HG and PG groups). We find that earlier-type (brighter) galaxies are more clustered and lie closer to the group centers, both in position and in velocity, than later-type (fainter) galaxies. Spatial segregations are stronger than kinematical segregations. These effects are generally detected at the >˜ 3-sigma level. Luminosity segregation is shown to be independent of morphology segregation. Our main conclusions are strengthened by the detection of segregation in both hierarchical and percolation catalogs. Our results agree with a continuum of segregation properties of galaxies in systems, from low-mass groups to massive clusters.

Mapping of within-species segregation distortion in D. persimilis and hybrid sterility between D. persimilis and D. pseudoobscura

PubMed Central

McDermott, Shannon R.; Noor, Mohamed A. F.

2012-01-01

In contrast to the prevailing dogma in the 1990s, recent studies have suggested that an evolutionary history of segregation distortion within species may contribute to sterility in species hybrids. However, this recent work identified segregation distortion exclusively in species hybrids which may never have had an evolutionary history of segregation distortion in either parent species. We expand on previous work by using a strain of Drosophila persimilis exhibiting segregation distortion within species to generate QTL maps for segregation distortion and hybrid sterility in crosses between D. persimilis and D. pseudoobscura. The maps localize regions along the XR contributing to both phenotypes, and they indicate one region of overlap between the two maps. This overlap could provide preliminary evidence for an association between segregation distortion within species and hybrid sterility, but the localizations are currently too broad to have confidence in this conclusion. This work is a first step towards possibly supporting a genetic conflict model of speciation in this system. PMID:22966762

Transport analogy for segregation and granular rheology

NASA Astrophysics Data System (ADS)

Liu, Siying; McCarthy, Joseph J.

2017-08-01

Here, we show a direct connection between density-based segregation and granular rheology that can lead to insight into both problems. Our results exhibit a transition in the rate of segregation during simple shear that occurs at I ˜0.5 and mimics a coincident regime change in flow rheology. We propose scaling arguments that support a packing fraction criterion for this transition that can both explain our segregation results as well as unify existing literature studies of granular rheology. By recasting a segregation model in terms of rheological parameters, we establish an approach that not only collapses results for a wide range of conditions, but also yields a direct relationship between the coordination number z and the segregation velocity. Moreover, our approach predicts the precise location of the observed regime change or saturation. This suggests that it is possible to rationally design process operating conditions that lead to significantly lower segregation extents. These observations can have a profound impact on both the study of granular flow or mixing as well as industrial practice.

Patterns of local segregation: Do they matter for neighborhood crime?

PubMed

Krivo, Lauren J; Byron, Reginald A; Calder, Catherine A; Peterson, Ruth D; Browning, Christopher R; Kwan, Mei-Po; Lee, Jae Yong

2015-11-01

In this paper, we extend recent research on the spatial measurement of segregation and the spatial dynamics of urban crime by conceptualizing, measuring, and describing local segregation by race-ethnicity and economic status, and examining the linkages of these conditions with levels of neighborhood violent and property crime. The analyses are based on all 8895 census tracts within a sample of 86 large U.S. cities. We fit multilevel models of crime that incorporate measures of local segregation. The results reveal that, net of city-level and neighborhood characteristics, White-Black local segregation is associated with lower violent and property crime. In contrast, local segregation of low income from high income households is connected with higher crime, particularly neighborhood violence. Copyright © 2015 Elsevier Inc. All rights reserved.

Is formation segregation melts in basaltic lava flows a viable analogue to melt generation in basaltic systems?

NASA Astrophysics Data System (ADS)

Thordarson, Thorvaldur; Sigmarsson, Olgeir; Hartley, Margaret E.; Miller, Jay

2010-05-01

Pahoehoe sheet lobes commonly exhibit a three-fold structural division into upper crust, core and lower crust, where the core corresponds to the liquid portion of an active lobe sealed by crust. Segregations are common in pahoehoe lavas and are confined to the core of individual lobes. Field relations and volume considerations indicate that segregation is initiated by generation of volatile-rich melt at or near the lower crust to core boundary via in-situ crystallization. Once buoyant, the segregated melt rises through the core during last stages of flow emplacement and accumulates at the base of the upper crust. The segregated melt is preserved as vesicular and aphyric, material within well-defined vesicle cylinders and horizontal vesicle sheets that make up 1-4% of the total lobe volume. We have undertaken a detailed sampling and chemical analysis of segregations and their host lava from three pahoehoe flow fields; two in Iceland and one in the Columbia River Basalt Group (CRBG). The Icelandic examples are: the olivine-tholeiite Thjorsa lava (24 cubic km) of the Bardarbunga-Veidivotn volcanic system and mildly alkalic Surtsey lavas (1.2 cubic km) of the Vestmannaeyjar volcanic system. The CRBG example is the tholeiitic ‘high-MgO group' Levering lava (>100? cubic km) of the N2 Grande Ronde Basalt. The thicknesses of the sampled lobes ranges from 2.3 to 14 m and each lobe feature well developed network of segregation structures [1,2,3]. Our whole-rock analyses show that the segregated melt is significantly more evolved than the host lava, with enrichment factors of 1.25 (Thjorsa) to 2.25 (Surtsey) for incompatible trace elements (Ba, Zr). Calculations indicate that the segregation melt was formed by 20 to 50% closed-system fractional crystallization of plagioclase (plus minor pyroxene and/or olivine). A more striking feature is the whole-rock composition of the segregations. In the olivine-tholeiite Thjorsa lava the segregations exhibit quartz tholeiite composition that is identical to the magma compositions produced by the nearby Grimsvotn and Kverkfjoll volcanic systems during the Holocene. The Surtsey segregations have whole-rock composition remarkably similar to the FeTi basalts from adjacent Katla volcanic system, whereas the segregations of the Levering flow are identical to the ‘low-MgO group' basalts of the CRBG. Is this a coincidence or does volatile induced liquid transfer, as inferred for the formation of the segregations, play an important role in magma differentiation in basaltic systems? [1]Thordarson & Self The Roza Member, Columbia River Basalt Group. J Geophys Res - Solid Earth [2] Sigmarsson, et al, 2009. Segregations in Surtsey lavas (Iceland). In Studies in Volcanology: The Legacy of George Walker. Special Publication of IAVCEI No 3. [3] Hartley & Thordarson, 2009, Melt segregations in a Columbia River Basalt lava flow. Lithos

43 CFR 2091.07 - Principles.

Code of Federal Regulations, 2012 CFR

2012-10-01

... the Geothermal Steam Act, if so specified in the document that segregates the lands. The segregation... regulations or in the document that segregates the lands. Where there is an administrative appeal or review...

43 CFR 2091.07 - Principles.

Code of Federal Regulations, 2013 CFR

2013-10-01

... the Geothermal Steam Act, if so specified in the document that segregates the lands. The segregation... regulations or in the document that segregates the lands. Where there is an administrative appeal or review...

43 CFR 2091.07 - Principles.

Code of Federal Regulations, 2014 CFR

2014-10-01

... the Geothermal Steam Act, if so specified in the document that segregates the lands. The segregation... regulations or in the document that segregates the lands. Where there is an administrative appeal or review...

A STATEMENT OF CONCERN FOR PUBLIC EDUCATION IN PHILADELPHIA, WITH PARTICULAR REFERENCE TO THE SPECIAL NEEDS OF CHILDREN IN UNDERPRIVILEGED, SEGREGATED AREAS.

ERIC Educational Resources Information Center

Commission on Human Relations, Philadelphia, PA.

THIS 1960 STATEMENT OF THE COMMISSION ON HUMAN RELATIONS DESCRIBES THE PROBLEM OF DE FACTO SEGREGATION IN PHILADELPHIA. THE EXTENT OF SCHOOL AND FACULTY SEGREGATION IS INDICATED, AND THE REASONS FOR ITS EXISTENCE ARE DISCUSSED. IT IS FELT THAT THE CULTURAL DEFICIT WHICH RESULTS FROM RACIAL DISCRIMINATION AND SEGREGATION REQUIRES COMPENSATORY…

Black-White Residential Segregation: The Views of Myrdal in the 1940s and Trends of the 1980s.

ERIC Educational Resources Information Center

Farley, Reynolds

1994-01-01

Traces the development of black-white residential segregation in U.S. cities, and applies the views of Gunnar Myrdal, expressed in the 1940s, to housing trends in the 1980s. While such segregation has decreased, blacks remain more segregated than two other large minority groups (i.e., Hispanics and Asians). Forces influencing residential…

77 FR 12874 - Notice of Segregation of Public Lands in the State of Arizona Associated With the Proposed Mohave...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

...; AZA32315] Notice of Segregation of Public Lands in the State of Arizona Associated With the Proposed Mohave... material sales acts, for a period of 2 years. This segregation is being made in connection with the BLM's... County Wind Farm Project (Proposed Project). This segregation covers approximately 38,016.60 acres of BLM...

Segregation at the surfaces of CuxPd1-x alloys in the presence of adsorbed S

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

Miller, James B.; Priyadarshini, Deepika; Gellman, Andrew J.

2012-10-01

The influence of adsorbed S on surface segregation in Cu{sub x}Pd{sub 1 - x} alloys (S/Cu{sub x}Pd{sub 1 - x)} was characterized over a wide range of bulk alloy compositions (x = 0.05 to 0.95) using high-throughput Composition Spread Alloy Film (CSAF) sample libraries. Top-surface and near-surface compositions of the CSAFs were measured as functions of bulk Cu composition, x, and temperature using spatially resolved low energy ion scattering spectroscopy (LEISS) and X-ray photoemission spectroscopy (XPS). Preferential segregation of Cu to the top-surface of the S/Cu{sub x}Pd{sub 1 - x} CSAF was observed at all bulk compositions, x, but themore » extent of Cu segregation to the S/Cu{sub x}Pd{sub 1 - x} surface was lower than the Cu segregation to the surface of a clean Cu{sub x}Pd{sub 1 - x} CSAF, clear evidence of an S-induced “segregation reversal.” The Langmuir–McLean formulation of the Gibbs isotherm was used to estimate the enthalpy and entropy of Cu segregation to the top-surface, ΔH{sub seg}(x) and ΔS{sub seg}(x), at saturation sulfur coverages. While Cu segregation to the top-surface of the clean Cu{sub x}Pd{sub 1 - x} is exothermic (ΔH{sub seg} < 0) for all bulk Cu compositions, it is endothermic (ΔH{sub seg} > 0) for S/Cu{sub x}Pd{sub 1 - x}. Segregation to the S/Cu{sub x}Pd{sub 1 - x} surface is driven by entropy. Changes in segregation patterns that occur upon adsorption of S onto Cu{sub x}Pd{sub 1 - x} appear to be related to formation of energetically favored Pd{single bond}S bonds at the surface, which counterbalance the enthalpic driving forces for Cu segregation to the clean surface.« less

Enhanced electrical conductivity and piezoresistive sensing in multi-wall carbon nanotubes/polydimethylsiloxane nanocomposites via the construction of a self-segregated structure.

PubMed

Wang, Ming; Zhang, Kai; Dai, Xin-Xin; Li, Yin; Guo, Jiang; Liu, Hu; Li, Gen-Hui; Tan, Yan-Jun; Zeng, Jian-Bing; Guo, Zhanhu

2017-08-10

Formation of highly conductive networks is essential for achieving flexible conductive polymer composites (CPCs) with high force sensitivity and high electrical conductivity. In this study, self-segregated structures were constructed in polydimethylsiloxane/multi-wall carbon nanotube (PDMS/MWCNT) nanocomposites, which then exhibited high piezoresistive sensitivity and low percolation threshold without sacrificing their mechanical properties. First, PDMS was cured and pulverized into 40-60 mesh-sized particles (with the size range of 250-425 μm) as an optimum self-segregated phase to improve the subsequent electrical conductivity. Then, the uncured PDMS/MWCNT base together with the curing agent was mixed with the abovementioned PDMS particles, serving as the segregated phase. Finally, the mixture was cured again to form the PDMS/MWCNT nanocomposites with self-segregated structures. The morphological evaluation indicated that MWCNTs were located in the second cured three-dimensional (3D) continuous PDMS phase, resulting in an ultralow percolation threshold of 0.003 vol% MWCNTs. The nanocomposites with self-segregated structures with 0.2 vol% MWCNTs achieved a high electrical conductivity of 0.003 S m -1 , whereas only 4.87 × 10 -10 S m -1 was achieved for the conventional samples with 0.2 vol% MWCNTs. The gauge factor GF of the self-segregated samples was 7.4-fold that of the conventional samples at 30% compression strain. Furthermore, the self-segregated samples also showed higher compression modulus and strength as compared to the conventional samples. These enhanced properties were attributed to the construction of 3D self-segregated structures, concentrated distribution of MWCNTs, and strong interfacial interaction between the segregated phase and the continuous phase with chemical bonds formed during the second curing process. These self-segregated structures provide a new insight into the fabrication of elastomers with high electrical conductivity and piezoresistive sensitivity for flexible force-sensitive materials.

Effect of steady crucible rotation on the segregation of impurities in vertical Bridgman growth of multi-crystalline silicon

NASA Astrophysics Data System (ADS)

Bellmann, M. P.; Meese, E. A.

2011-10-01

We have performed axisymmetric, transient simulations of the vertical Bridgman growth of multi-crystalline (mc) silicon to study the effect of the steady crucible rotation on the melt flow and impurity segregation. A solute transport model has been applied to predict the final segregation pattern of impurities in a circular ingot. Imposing rotation rates of 1-5 rpm on the system makes radial segregation much worse compared to the non-rotating case. Low rotation rates at 1-2 rpm increase radial segregation in the first half period of solidification, whereas at rotation rates above the effect is insignificantly small. Contrary behavior was observed for the second half period of solidification. Here radial segregation is increased at high rotation rates from 3 to 5 rpm with small impact at 1-2 rpm.

Residential segregation, political representation, and preterm birth among U.S.- and foreign-born Black women in the U.S. 2008-2010.

PubMed

Margerison-Zilko, Claire; Perez-Patron, Maria; Cubbin, Catherine

2017-07-01

Although racial residential segregation is associated with preterm birth (PTB) among non-Hispanic black (NHB) women in the U.S., prior work suggests that increased black political power arising from segregation may be protective for infant health. We examined associations between residential segregation, black political representation, and preterm birth (PTB) among U.S- and foreign-born NHB women in major U.S. cities using birth certificate data from 2008 to 2010 (n=861,450). Each 10-unit increase in segregation was associated with 3-6% increases in odds of PTB for both U.S.- and foreign-born NHB women. Black political representation was not associated with PTB and did not moderate the association between residential segregation and PTB. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beyond the Census Tract: Patterns and Determinants of Racial Segregation at Multiple Geographic Scales*

PubMed Central

Lee, Barrett A.; Reardon, Sean F.; Firebaugh, Glenn; Farrell, Chad R.; Matthews, Stephen A.; O'Sullivan, David

2014-01-01

The census tract-based residential segregation literature rests on problematic assumptions about geographic scale and proximity. We pursue a new tract-free approach that combines explicitly spatial concepts and methods to examine racial segregation across egocentric local environments of varying size. Using 2000 census data for the 100 largest U.S. metropolitan areas, we compute a spatially modified version of the information theory index H to describe patterns of black-white, Hispanic-white, Asian-white, and multi-group segregation at different scales. The metropolitan structural characteristics that best distinguish micro-segregation from macro-segregation for each group combination are identified, and their effects are decomposed into portions due to racial variation occurring over short and long distances. A comparison of our results to those from tract-based analyses confirms the value of the new approach. PMID:25324575

Racial residential segregation: a fundamental cause of racial disparities in health.

PubMed

Williams, D R; Collins, C

2001-01-01

Racial residential segregation is a fundamental cause of racial disparities in health. The physical separation of the races by enforced residence in certain areas is an institutional mechanism of racism that was designed to protect whites from social interaction with blacks. Despite the absence of supportive legal statutes, the degree of residential segregation remains extremely high for most African Americans in the United States. The authors review evidence that suggests that segregation is a primary cause of racial differences in socioeconomic status (SES) by determining access to education and employment opportunities. SES in turn remains a fundamental cause of racial differences in health. Segregation also creates conditions inimical to health in the social and physical environment. The authors conclude that effective efforts to eliminate racial disparities in health must seriously confront segregation and its pervasive consequences.

Self-rated health and residential segregation: how does race/ethnicity matter?

PubMed

Gibbons, Joseph; Yang, Tse-Chuan

2014-08-01

Despite recent declines, racial segregation remains a detriment to minority neighborhoods. However, existing research is inconclusive as to the effects racial segregation has on health. Some argue that racial segregation is related to poor health outcomes, whereas others suspect that racial segregation may actually lead to improved health for some minority communities. Even less is known about whether minority access to white neighborhoods improves health. We address these gaps with individual data from the 2010 Public Health Management Corporation's Southeastern Pennsylvania Household Health Survey and census tract data from the 2010 Decennial Census and the 2006-2010 American Community Survey. We implement logistic multilevel models to determine whether and how a resident's self-rated health is affected by the racial/ethnic segregation of their neighborhoods. Our key finding suggests that the effects of segregation on self-rated health depend on an individual's race/ethnicity, with blacks and Latino residents most likely to experience adverse effects. Particularly, minorities living in predominantly white communities have a significantly higher likelihood to report poor/fair health than they would in segregated minority neighborhoods. These findings make clear that access to white neighborhoods is not sufficient to improve minority health; fuller neighborhood integration is necessary to ensure all have health equity.

Agents of Change: Mixed-Race Households and the Dynamics of Neighborhood Segregation in the United States

PubMed Central

Ellis, Mark; Holloway, Steven R.; Wright, Richard; Fowler, Christopher S.

2014-01-01

This article explores the effects of mixed-race household formation on trends in neighborhood-scale racial segregation. Census data show that these effects are nontrivial in relation to the magnitude of decadal changes in residential segregation. An agent-based model illustrates the potential long-run impacts of rising numbers of mixed-race households on measures of neighborhood-scale segregation. It reveals that high rates of mixed-race household formation will reduce residential segregation considerably. This occurs even when preferences for own-group neighbors are high enough to maintain racial separation in residential space in a Schelling-type model. We uncover a disturbing trend, however; levels of neighborhood-scale segregation of single-race households can remain persistently high even while a growing number of mixed-race households drives down the overall rate of residential segregation. Thus, the article’s main conclusion is that parsing neighborhood segregation levels by household type—single versus mixed race—is essential to interpret correctly trends in the spatial separation of racial groups, especially when the fraction of households that are mixed race is dynamic. More broadly, the article illustrates the importance of household-scale processes for urban outcomes and joins debates in geography about interscalar relationships. PMID:25082984

Effect of steady crucible rotation on segregation in high-pressure vertical Bridgman growth of cadmium zinc telluride

NASA Astrophysics Data System (ADS)

Yeckel, Andrew; Patrick Doty, F.; Derby, Jeffrey J.

1999-05-01

Three-dimensional axisymmetric, time-dependent simulations of the high-pressure vertical Bridgman growth of large-diameter cadmium zinc telluride are performed to study the effect of steady crucible rotation on axial and radial segregation in the grown crystal. The model includes details of heat transfer, melt convection, solid-liquid interface shape, and pseudo-binary zinc segregation. Imposing a moderate rotation rate of 10 rpm on the system slightly improves axial segregation but makes radial segregation much worse. Moreover, values of dimensionless thermal Rossby and Taylor numbers calculated for this system indicate that the baroclinic instability may occur at the rotation rates studied.

Effect of accelerated crucible rotation on the segregation of impurities in vertical Bridgman growth of multi-crystalline silicon

NASA Astrophysics Data System (ADS)

Bellmann, M. P.; Meese, E. A.; Arnberg, L.

2011-03-01

We have performed axisymmetric, transient simulations of the vertical Bridgman growth of mc-silicon to study the effect of the accelerated crucible rotation technique (ACRT) on the melt flow and impurity segregation. A solute transport model has been applied to predict the final segregation pattern of impurities in a circular ingot. The sinusoidal ACRT rotation cycle considered here suppresses mixing in the melt near the center, resulting in diffusion-limited mass transport. Therefore the radial impurity segregation is increased towards the center. The effect of increased radial segregation is intensified for low values of the Ekman time scale.

The Segregation Academy and the Law

ERIC Educational Resources Information Center

Champagne, Anthony M.

1973-01-01

A case study of one private school which functions as a segregation academy'' was done in order to learn more about what segregation academies are, how they operate, and how they relate to the community. (Author/JM)

Mapping of within-species segregation distortion in Drosophila persimilis and hybrid sterility between D. persimilis and D. pseudoobscura.

PubMed

McDermott, S R; Noor, M A F

2012-10-01

In contrast to the prevailing dogma in the 1990s, recent studies have suggested that an evolutionary history of segregation distortion within species may contribute to sterility in species hybrids. However, this recent work identified segregation distortion exclusively in species hybrids that may never have had an evolutionary history of segregation distortion in either parent species. We expand on previous work using a strain of Drosophila persimilis exhibiting segregation distortion within species to generate QTL maps for segregation distortion and hybrid sterility in crosses between D. persimilis and D. pseudoobscura. The maps localize regions along the XR contributing to both phenotypes, and they indicate one region of overlap between the two maps. This overlap could provide preliminary evidence for an association between segregation distortion within species and hybrid sterility, but the localizations are currently too broad to have confidence in this conclusion. This work is a first step towards possibly supporting a genetic conflict model of speciation in this system. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Elevating the frequency of chromosome mis-segregation as a strategy to kill tumor cells

PubMed Central

Janssen, Aniek; Kops, Geert J. P. L.; Medema, René H.

2009-01-01

The mitotic checkpoint has evolved to prevent chromosome mis-segregations by delaying mitosis when unattached chromosomes are present. Inducing severe chromosome segregation errors by ablating the mitotic checkpoint causes cell death. Here we have analyzed the consequences of gradual increases in chromosome segregation errors on the viability of tumor cells and normal human fibroblasts. Partial reduction of essential mitotic checkpoint components in four tumor cell lines caused mild chromosome mis-segregations, but no lethality. These cells were, however, remarkably more sensitive to low doses of taxol, which enhanced the amount and severity of chromosome segregation errors. Sensitization to taxol was achieved by reducing levels of Mps1 or BubR1, proteins having dual roles in checkpoint activation and chromosome alignment, but not by reducing Mad2, functioning solely in the mitotic checkpoint. Moreover, we find that untransformed human fibroblasts with reduced Mps1 levels could not be sensitized to sublethal doses of taxol. Thus, targeting the mitotic checkpoint and chromosome alignment simultaneously may selectively kill tumor cells by enhancing chromosome mis-segregations. PMID:19855003

Heats of Segregation of BCC Metals Using Ab Initio and Quantum Approximate Methods

NASA Technical Reports Server (NTRS)

Good, Brian; Chaka, Anne; Bozzolo, Guillermo

2003-01-01

Many multicomponent alloys exhibit surface segregation, in which the composition at or near a surface may be substantially different from that of the bulk. A number of phenomenological explanations for this tendency have been suggested, involving, among other things, differences among the components' surface energies, molar volumes, and heats of solution. From a theoretical standpoint, the complexity of the problem has precluded a simple, unified explanation, thus preventing the development of computational tools that would enable the identification of the driving mechanisms for segregation. In that context, we investigate the problem of surface segregation in a variety of bcc metal alloys by computing dilute-limit heats of segregation using both the quantum-approximate energy method of Bozzolo, Ferrante and Smith (BFS), and all-electron density functional theory. In addition, the composition dependence of the heats of segregation is investigated using a BFS-based Monte Carlo procedure, and, for selected cases of interest, density functional calculations. Results are discussed in the context of a simple picture that describes segregation behavior as the result of a competition between size mismatch and alloying effects

Auger electron spectroscopy study of surface segregation in the binary alloys copper-1 atomic percent indium, copper-2 atomic percent tin, and iron-6.55 atomic percent silicon

NASA Technical Reports Server (NTRS)

Ferrante, J.

1973-01-01

Auger electron spectroscopy was used to examine surface segregation in the binary alloys copper-1 at. % indium, copper-2 at. % tin and iron-6.55 at. % silicon. The copper-tin and copper-indium alloys were single crystals oriented with the /111/ direction normal to the surface. An iron-6.5 at. % silicon alloy was studied (a single crystal oriented in the /100/ direction for study of a (100) surface). It was found that surface segregation occurred following sputtering in all cases. Only the iron-silicon single crystal alloy exhibited equilibrium segregation (i.e., reversibility of surface concentration with temperature) for which at present we have no explanation. McLean's analysis for equilibrium segregation at grain boundaries did not apply to the present results, despite the successful application to dilute copper-aluminum alloys. The relation of solute atomic size and solubility to surface segregation is discussed. Estimates of the depth of segregation in the copper-tin alloy indicate that it is of the order of a monolayer surface film.

Molecular mechanisms of homologous chromosome pairing and segregation in plants.

PubMed

Zhang, Jing; Zhang, Bing; Su, Handong; Birchler, James A; Han, Fangpu

2014-03-20

In most eukaryotic species, three basic steps of pairing, recombination and synapsis occur during prophase of meiosis I. Homologous chromosomal pairing and recombination are essential for accurate segregation of chromosomes. In contrast to the well-studied processes such as recombination and synapsis, many aspects of chromosome pairing are still obscure. Recent progress in several species indicates that the telomere bouquet formation can facilitate homologous chromosome pairing by bringing chromosome ends into close proximity, but the sole presence of telomere clustering is not sufficient for recognizing homologous pairs. On the other hand, accurate segregation of the genetic material from parent to offspring during meiosis is dependent on the segregation of homologs in the reductional meiotic division (MI) with sister kinetochores exhibiting mono-orientation from the same pole, and the segregation of sister chromatids during the equational meiotic division (MII) with kinetochores showing bi-orientation from the two poles. The underlying mechanism of orientation and segregation is still unclear. Here we focus on recent studies in plants and other species that provide insight into how chromosomes find their partners and mechanisms mediating chromosomal segregation. Copyright © 2013. Published by Elsevier Ltd.

Nonequilibrium segregation and phase instability in alloy films during elevated-temperature irradiation in a high-voltage electron microscope

NASA Astrophysics Data System (ADS)

Lam, N. Q.; Okamoto, P. R.

1984-05-01

The effects of defect-production rate gradients, caused by the radial nonuniformity in the electron flux distribution, on solute segregation and phase stability in alloy films undergoing high-voltage electron-microscope (HVEM) irradiation at high temperatures are assessed. Two-dimensional (axially symmetric) compositional redistributions were calculated, taking into account both axial and transverse radial defect fluxes. It was found that when highly focused beams were employed radiation-induced segregation consisted of two stages: dominant axial segregation at the film surfaces at short irradiation times and competitive radial segregation at longer times. The average alloy composition within the irradiated region could differ greatly from that irradiated with a uniform beam, because of the additional atom transport from or to the region surrounding the irradiated zone under the influence of radial fluxes. Damage-rate gradient effects must be taken into account when interpreting in-situ HVEM observations of segregation-induced phase instabilities. The theoretical predictions are compared with experimental observations of the temporal and spatial dependence of segregation-induced precipitation in thin films of Ni-Al, Ni-Ge and Ni-Si solid solutions.

Segregation physics of a macroscale granular ratchet

NASA Astrophysics Data System (ADS)

Bhateja, Ashish; Sharma, Ishan; Singh, Jayant K.

2017-05-01

New experiments with multigrain mixtures in a laterally shaken, horizontal channel show complete axial segregation of species. The channel consists of multiple concatenated trapeziums, and superficially resembles microratchets wherein asymmetric geometries and potentials transport, and sort, randomly agitated microscopic particles. However, the physics of our macroscale granular ratchet is fundamentally different, as macroscopic segregation is gravity driven. Our observations are not explained by classical granular segregation theories either. Motivated by the experiments, extensive parallelized discrete element simulations reveal that the macroratchet differentiates grains through hierarchical bidirectional segregation over two different time scales: Grains rapidly sort vertically into horizontal bands spanning the channel's length that, subsequently, slowly separate axially, driven by strikingly gentle, average interfacial pressure gradients acting over long distances. At its maximum, the pressure gradient responsible for axial separation was due to a change in height of about two big grain diameters (d =7 mm) over a meter-long channel. The strong directional segregation achieved by the granular macroratchet has practical importance, while identifying the underlying new physics will further our understanding of granular segregation in industrial and geophysical processes.

Development of Computational Tools for Modeling Thermal and Radiation Effects on Grain Boundary Segregation and Precipitation in Fe-Cr-Ni-based Alloys

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

Yang, Ying

This work aims at developing computational tools for modeling thermal and radiation effects on solute segregation at grain boundaries (GBs) and precipitation. This report described two major efforts. One is the development of computational tools on integrated modeling of thermal equilibrium segregation (TES) and radiation-induced segregation (RIS), from which synergistic effects of thermal and radiation, pre-existing GB segregation have been taken into consideration. This integrated modeling was used in describing the Cr and Ni segregation in the Fe-Cr-Ni alloys. The other effort is thermodynamic modeling on the Fe-Cr-Ni-Mo system which includes the major alloying elements in the investigated alloys inmore » the Advanced Radiation Resistant Materials (ARRM) program. Through thermodynamic calculation, we provide baseline thermodynamic stability of the hardening phase Ni2(Cr,Mo) in selected Ni-based super alloys, and contribute knowledge on mechanistic understanding on the formation of Ni2(Cr,Mo) in the irradiated materials. The major outcomes from this work are listed in the following: 1) Under the simultaneous thermal and irradiation conditions, radiation-induced segregation played a dominant role in the GB segregation. The pre-existing GB segregation only affects the subsequent radiation-induced segregation in the short time. For the same element, the segregation tendency of Cr and Ni due to TES is opposite to it from RIS. The opposite tendency can lead to the formation of W-shape profile. These findings are consistent with literature observation of the transitory W-shape profile. 2) While TES only affects the distance of one or two atomic layers from GBs, the RIS can affect a broader distance from GB. Therefore, the W-shape due to pre-existing GB segregation is much narrower than that due to composition gradient formed during the transient state. Considering the measurement resolution of Auger or STEM analysis, the segregation tendency due to RIS should play a dominant role in the measured values. However, The GB segregation due to pre-existing GB segregation may affect the chemical potential of element at GB, and subsequently the corrosion resistance. 3) Based on the newly developed thermodynamic database of Fe-Cr-Ni-Mo, we predicted the Ni2(Cr,Mo) as a thermodynamically stable phase in all investigated low Fe-content Ni-based alloys. The calculated phase amount decreases with the increasing Fe content, being consistent with that observed in the irradiated materials. 4) The formation of the Ni2(Cr,Mo) phase in irradiated materials is due to irradiation enhanced diffusion. The calculated equilibrium Ni2(Cr,Mo) amount is more than that observed in the irradiated materials, suggesting that the amount of Ni2(Cr,Mo) is likely to increase more with further irradiation.« less

Segregation Phenomena on the Crystal Surface of Chemical Compounds

NASA Astrophysics Data System (ADS)

Tomashpol'skii, Yu. Ya.

2018-06-01

The current state of the theoretical and experimental studies of changes in the chemical structure and composition caused by segregation phenomena on the surface of chemical compounds was reviewed. The review considers the experimental data obtained exclusively on single crystals, which were studied by modern instrumental methods, including in situ Auger electron spectrometry, X-ray spectral microanalysis, high-resolution scanning and transmission electron microscopy, secondary electron emission, and atomic force microscopy. The models that suggest the crystal-chemical diffusion and liquid-phase mechanisms of segregation were described. The parameters of the theory include the type of chemical bond, elastic constants, and crystal-chemical characteristics of substances. The models make it possible to predict the nature of changes in the surface composition: segregation tendency, segregant type, and degree of nonstoichiometry. A new direction in surface segregation was considered, which is promising for nanoelectronics and emission electronics.

Racial/Ethnic Residential Segregation, Obesity, and Diabetes Mellitus.

PubMed

Kershaw, Kiarri N; Pender, Ashley E

2016-11-01

Persistent racial/ethnic disparities in obesity and type 2 diabetes mellitus seen in the US are likely due to a combination of social, biological, and environmental factors. A growing number of studies have examined the role of racial/ethnic residential segregation with respect to these outcomes because this macro-level process is believed to be a fundamental cause of many of the factors that contribute to these disparities. This review provides an overview of findings from studies of racial/ethnic residential segregation with obesity and diabetes published between 2013 and 2015. Findings for obesity varied by geographic scale of the segregation measure, gender, ethnicity, and racial identity (among Hispanics/Latinos). Recent studies found no association between racial/ethnic residential segregation and diabetes prevalence, but higher segregation of Blacks was related to higher diabetes mortality. Implications of these recent studies are discussed as well as promising areas of future research.

A role for recombination junctions in the segregation of mitochondrial DNA in yeast.

PubMed

Lockshon, D; Zweifel, S G; Freeman-Cook, L L; Lorimer, H E; Brewer, B J; Fangman, W L

1995-06-16

In S. cerevisiae, mitochondrial DNA (mtDNA) molecules, in spite of their high copy number, segregate as if there were a small number of heritable units. The rapid segregation of mitochondrial genomes can be analyzed using mtDNA deletion variants. These small, amplified genomes segregate preferentially from mixed zygotes relative to wild-type mtDNA. This segregation advantage is abolished by mutations in a gene, MGT1, that encodes a recombination junction-resolving enzyme. We show here that resolvase deficiency causes a larger proportion of molecules to be linked together by recombination junctions, resulting in the aggregation of mtDNA into a small number of cytological structures. This change in mtDNA structure can account for the increased mitotic loss of mtDNA and the altered pattern of mtDNA segregation from zygotes. We propose that the level of unresolved recombination junctions influences the number of heritable units of mtDNA.

A first principles study on the electronic origins of silver segregation at the Ag-Au (111) surface

NASA Astrophysics Data System (ADS)

Hoppe, Sandra; Müller, Stefan

2017-12-01

The special electronic structure of gold gives rise to many interesting phenomena, such as its color. The surface segregation of the silver-gold system has been the subject of numerous experimental and theoretical studies, yielding conflicting results ranging from strong Ag surface enrichment to Au surface segregation. Via a combined approach of density functional theory (DFT) and statistical physics, we have analyzed the segregation at the Ag-Au (111) surface with different Ag bulk concentrations. Interestingly, we observe a moderate Au surface segregation, which is due to a charge transfer from the less electronegative Ag to Au. Canonical Monte Carlo simulations suggest that the calculated concentration profile with a Au-enriched surface layer remains stable up to higher temperatures. However, the presence of adsorbed oxygen reverses the segregation behavior and leads to strong Ag enrichment of the surface layer.

Vascular endothelial growth factor signaling regulates the segregation of artery and vein via ERK activity during vascular development

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

Kim, Se-Hee; Schmitt, Christopher E.; Woolls, Melissa J.

Highlights: ► VEGF-A signaling regulates the segregation of axial vessels. ► VEGF-A signaling is mediated by PKC and ERK in this process. ► Ectopic activation of ERK is sufficient to rescue defects in vessel segregation. -- Abstract: Segregation of two axial vessels, the dorsal aorta and caudal vein, is one of the earliest patterning events occur during development of vasculature. Despite the importance of this process and recent advances in our understanding on vascular patterning during development, molecular mechanisms that coordinate the segregation of axial vessels remain largely elusive. In this report, we find that vascular endothelial growth factor-A (Vegf-A)more » signaling regulates the segregation of dorsal aorta and axial vein during development. Inhibition of Vegf-A pathway components including ligand Vegf-A and its cognate receptor Kdrl, caused failure in segregation of axial vessels in zebrafish embryos. Similarly, chemical inhibition of Mitogen-activated protein kinase kinase (Map2k1)/Extracellular-signal-regulated kinases (Erk) and phosphatidylinositol 3-kinases (PI3 K), which are downstream effectors of Vegf-A signaling pathway, led to the fusion of two axial vessels. Moreover, we find that restoring Erk activity by over-expression of constitutively active MEK in embryos with a reduced level of Vegf-A signaling can rescue the defects in axial vessel segregation. Taken together, our data show that segregation of axial vessels requires the function of Vegf-A signaling, and Erk may function as the major downstream effector in this process.« less

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.

Associations of neighborhood-level racial residential segregation with adverse pregnancy outcomes.

PubMed

Salow, Arturo D; Pool, Lindsay R; Grobman, William A; Kershaw, Kiarri N

2018-03-01

Previous analyses utilizing birth certificate data have shown environmental factors such as racial residential segregation may contribute to disparities in adverse pregnancy outcomes. However, birth certificate data are ill equipped to reliably differentiate among small for gestational age, spontaneous preterm birth, and medically indicated preterm birth. We sought to utilize data from electronic medical records to determine whether residential segregation among Black women is associated with an increased risk of adverse pregnancy outcomes. The study population was composed of 4770 non-Hispanic Black women who delivered during the years 2009 through 2013 at a single urban medical center. Addresses were geocoded at the level of census tract, and this tract was used to determine the degree of residential segregation for an individual's neighborhood. Residential segregation was measured using the Gi* statistic, a z-score that measures the extent to which the neighborhood racial composition deviates from the composition of the larger surrounding area. The Gi* statistic z-scores were categorized as follows: low (z < 0), medium (z = 0-1.96), and high (z > 1.96). Adverse pregnancy outcomes included overall preterm birth, spontaneous preterm birth, medically indicated preterm birth, and small for gestational age. Hierarchical logistic regression models accounting for clustering by census tract and repeated births among mothers were used to estimate odds ratios of adverse pregnancy outcomes associated with segregation. In high segregation areas, the prevalence of overall preterm birth was significantly higher than that in low segregation areas (15.5% vs 10.7%, respectively; P < .001). Likewise, the prevalence of spontaneous preterm birth and medically indicated preterm birth were higher in high (9.5% and 6.0%) vs low (6.2% and 4.6%) segregation neighborhoods (P < .001 and P = .046, respectively). The associations of high segregation with overall preterm birth (odds ratio, 1.31; 95% confidence interval, 1.02-1.69) and spontaneous preterm birth (odds ratio, 1.37; 95% confidence interval, 1.02-1.85) remained significant with adjustment for neighborhood poverty, insurance status, parity, and maternal medical conditions. Among non-Hispanic Black women in an urban area, high levels of segregation were independently associated with the higher odds of spontaneous preterm birth. These findings highlight one aspect of social determinants (ie, segregation) through which adverse pregnancy outcomes may be influenced and points to a potential target for intervention. Copyright © 2018 Elsevier Inc. All rights reserved.

Impact of segregation energetics on oxygen conductivity at ionic grain boundaries

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

Aidhy, Dilpuneet S; Zhang, Yanwen; Weber, William J

2014-01-01

In pursuit of whether nanocrystallinity could lead to higher anion conductivity, research has revealed contradicting results exposing the limited understanding of point defect energetics at grain boundaries (GBs)/interfaces. By disentangling and addressing key GB energetics issues, i.e., segregation, migration and binding energies of oxygen vacancies in the presence and absence of dopants at the GBs, and the segregation energetics of dopants, we elucidate, using atomic simulations of doped ceria, that dopant segregation is the key factor leading to degradation of oxygen conductivity in nanocrystalline materials. A framework for designing enhanced conducting nanocrystalline materials is proposed where the focus of dopingmore » strategies shifts from bulk to segregation at GBs.« less

Influence of thermal convection on density segregation in a vibrated binary granular system.

PubMed

Windows-Yule, C R K; Weinhart, T; Parker, D J; Thornton, A R

2014-02-01

Using a combination of experimental results and discrete particle method simulations, the role of buoyancy-driven convection in the segregative behavior of a three-dimensional, binary granular system is investigated. A relationship between convective motion and segregation intensity is presented, and a qualitative explanation for this behavior is proposed. This study also provides an insight into the role of diffusive behavior in the segregation of a granular bed in the convective regime. The results of this work strongly imply the possibility that, for an adequately fluidized granular bed, the degree of segregation may be indirectly controlled through the adjustment of the system's driving parameters, or the dissipative properties of the system's side-boundaries.

Chromosome and cell wall segregation in Streptococcus faecium ATCC 9790

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

Higgins, M.L.; Glaser, D.; Dicker, D.T.

1989-01-01

Segregation was studied by measuring the positions of autoradiographic grain clusters in chains formed from single cells containing on average less than one radiolabeled chromosome strand. The degree to which chromosomal and cell wall material cosegregated was quantified by using the methods of S. Cooper and M. Weinberger, dividing the number of chains labeled at the middle. This analysis indicated that in contrast to chromosomal segregation in Escherichia coli and, in some studies, to that in gram-positive rods, chromosomal segregation in Streptococcus faecium was slightly nonrandom and did not vary with growth rate. Results were not significantly affected by strandmore » exchange. In contrast, labeled cell wall segregated predominantly nonrandomly.« less

Stochastic correlative firing for figure-ground segregation.

PubMed

Chen, Zhe

2005-03-01

Segregation of sensory inputs into separate objects is a central aspect of perception and arises in all sensory modalities. The figure-ground segregation problem requires identifying an object of interest in a complex scene, in many cases given binaural auditory or binocular visual observations. The computations required for visual and auditory figure-ground segregation share many common features and can be cast within a unified framework. Sensory perception can be viewed as a problem of optimizing information transmission. Here we suggest a stochastic correlative firing mechanism and an associative learning rule for figure-ground segregation in several classic sensory perception tasks, including the cocktail party problem in binaural hearing, binocular fusion of stereo images, and Gestalt grouping in motion perception.

MRI Measurements and Granular Dynamics Simulation of Segregation of Granular Mixture

NASA Technical Reports Server (NTRS)

Nakagawa, M.; Moss, Jamie L.; Altobelli, Stephen A.

1999-01-01

A counter intuitive axial segregation phenomenon in a rotating horizontal cylinder has recently captured attention of many researchers in different disciplines. There is a growing consensus that the interplay between the particle dynamics and the evolution of the internal structure during the segregation process must be carefully investigated. Magnetic resonance imaging (MRI) has been used to non-invasively obtain much needed dynamic/static information such as velocity and concentration profiles, and it has proven to be capable of depicting the evolution of segregation processes. Segregation in a rotating cylinder involves two processes: the first is to transport small particles in the radial direction to form a radial core, and the second is to transform the radial core into axially segregated bands. Percolation and/or "stopping" have been proposed as mechanisms for the radial segregation. As to mechanisms for axial band formation, much less is known. The difference in the dynamic angle of repose has been proposed to segregate different components in the axial direction. Recently, Hill and Kakalios have reported that particles mix or demix depending upon the competition between diffusion and preferential drift whose order can be determined by the dynamic angle of repose through the adjustment of the rotation rate. We claim that the dynamic angle of repose could be one of the causes, however, it fails to offer reasonable explanations for certain aspects of the axial migration. For example, we always observe that the radial segregation precedes the axial segregation and small particles migrate in the radial direction to form an axially extended radial core. It then transforms into axially segregated bands. By definition, the effects of the dynamic angle of repose are restricted near the free surface where the flowing layer is present. However, during the process of transforming from the radially segregated core to axially segregated bands, small particles located in the deep core region, which is untouched by the flowing layer, also completely disappear. Usually, the dynamics angle of repose are uniquely defined for individual species to characterize particle properties, and the dynamic angle of repose thus defined provides little information for the dynamic angle of repose of the mixture since the concentration ratio and the internal packing structure do not remain the same during the segregation processes. Under microgravity environment, the dynamics angle of repose argument does not hold since there is simply no flowing layer to influence/determine the preferred directions of segregation. We have thus designed an experiment so that the effects of the dynamic angle of repose can be minimized by filling the cylinder almost completely full. Small particles still formed a radial core and also migrated to form axial bands. As ground based experiments we have designed and conducted both 2D and 3D segregation experiments. The 2D experiments are performed using a thin cylinder (the gap between two end caps is about 5 mm) filled with different combinations of particles. The 3D experiments are conducted with a long cylinder of its length and diameter of 27cm and 7cm, respectively. Results of 2D experiments indicate that different mechanisms govern particle motion in regions near and far from the axis of rotation. Results of 3D experiments indicate that a series of collapses of microstructures of particle packing (micro-collapses) may be responsible for the creation of voids for small particles to migrate through in the axial direction. We have successfully eliminated the dynamic angle of repose as a cause for segregation, however, by almost completely filling the cylinder with the particles, we have lost an opportunity to investigate a possibility of particle "mobility" being a cause for segregation which requires a flowing surface but not the difference in the angle of repose. This is currently being investigated.

Effect of thermal and thermo-mechanical cycling on the boron segregation behavior in the coarse-grained heat-affected zone of low-alloy steel

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

Kim, Sanghoon; Kang, Yongjoon; Lee, Changhee, E-mail: chlee@hanyang.ac.kr

The boron segregation behavior in the coarse-grained heat-affected zone (CGHAZ) of 10 ppm boron-added low-alloy steel during the welding cycle was investigated by taking the changes in the microstructure and hardness into account. Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress, and the boron segregation behavior was analyzed by secondary ion mass spectrometry (SIMS) and particle tracking autoradiography (PTA). The segregation of boron was found to initially increase, and then decrease with an increase in the heat input. This is believed to be due to the back-diffusion of boron withmore » an increase in the exposure time at high temperature after non-equilibrium grain boundary segregation. The grain boundary segregation of boron could be decreased by an external stress applied during the welding cycle. Such behavior may be due to an increase in the grain boundary area as a result of the grain size reduction induced by the external stress. - Highlights: • Boron segregation behavior in the CGHAZ of low-alloy steel during a welding cycle was investigated. • Various CGHAZs were simulated with a Gleeble system as a function of the heat input and external stress. • Boron segregation behavior was analyzed using SIMS and PTA techniques.« less

Declining Segregation of Same-Sex Partners: Evidence from Census 2000 and 2010

PubMed Central

2013-01-01

Despite recent media and scholarly attention describing the “disappearance” of traditionally gay neighborhoods, urban scholars have yet to quantify the segregation of same-sex partners and determine whether declining segregation from different-sex partners is a wide-spread trend. Focusing on the 100 most populous places in the United States, I use data from the 2000 and 2010 Decennial Census to examine the segregation of same-sex partners over time and its place-level correlates. I estimate linear regression models to examine the role of four place characteristics in particular: average levels of education, aggregate trends in the family life cycle of same-sex partners, violence and social hostility motivated by sexual orientation bias, and representation of same-sex partners in the overall population. On average, same-sex partners were less segregated from different-sex partners in 2010 than in 2000, and the vast majority of same-sex partners lived in environments of declining segregation. Segregation was lower and declined more rapidly in places that had a greater percentage of graduate degree holders. In addition, segregation of female partners was lower in places that had a greater share of female partner households with children. These findings suggest that sexual orientation should be considered alongside economic status, race, and ethnicity as an important factor that contributes to neighborhood differentiation and urban spatial inequality. PMID:24187412

Characteristics of grouping colors for figure segregation on a multicolored background.

PubMed

Nagai, Takehiro; Uchikawa, Keiji

2008-11-01

A figure is segregated from its background when the colored elements belonging to the figure are grouped together. We investigated the range of color distribution conditions in which a figure could be segregated from its background using the color distribution differences. The stimulus was a multicolored texture composed of randomly shaped pieces. It was divided into two regions: a test region and a background region. The pieces in these two regions had different color distributions in the OSA Uniform Color Space. In our experiments, the subject segregated the figure of the test region using two different procedures. Since the Euclidean distance in the OSA Uniform Color Space corresponds to perceived color difference, if segregation thresholds are determined by only color difference, the thresholds should be independent of position and direction in the color space. In the results, however, the thresholds did depend on position and direction in the OSA Uniform Color Space. This suggests that color difference is not the only factor in figure segregation by color. Moreover, the threshold dependence on position and direction is influenced by the distances in the cone-opponent space whose axes are normalized by discrimination thresholds, suggesting that figure segregation threshold is determined by similar factors in the cone-opponent space for color discrimination. The analysis of the results by categorical color naming suggests that categorical color perception may affect figure segregation only slightly.

Declining Segregation of Same-Sex Partners: Evidence from Census 2000 and 2010.

PubMed

Spring, Amy L

2013-10-01

Despite recent media and scholarly attention describing the "disappearance" of traditionally gay neighborhoods, urban scholars have yet to quantify the segregation of same-sex partners and determine whether declining segregation from different-sex partners is a wide-spread trend. Focusing on the 100 most populous places in the United States, I use data from the 2000 and 2010 Decennial Census to examine the segregation of same-sex partners over time and its place-level correlates. I estimate linear regression models to examine the role of four place characteristics in particular: average levels of education, aggregate trends in the family life cycle of same-sex partners, violence and social hostility motivated by sexual orientation bias, and representation of same-sex partners in the overall population. On average, same-sex partners were less segregated from different-sex partners in 2010 than in 2000, and the vast majority of same-sex partners lived in environments of declining segregation. Segregation was lower and declined more rapidly in places that had a greater percentage of graduate degree holders. In addition, segregation of female partners was lower in places that had a greater share of female partner households with children. These findings suggest that sexual orientation should be considered alongside economic status, race, and ethnicity as an important factor that contributes to neighborhood differentiation and urban spatial inequality.

43 CFR 2091.0-5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of... described in this subpart. (b) Segregation means the removal for a limited period, subject to valid existing..., withdrawals, restorations, reservations, openings, classifications applications, segregations, leases, permits...

Ethnic Segregation in Arizona Charter Schools.

ERIC Educational Resources Information Center

Cobb, Casey D.; Glass, Gene V.

1999-01-01

Addressed whether Arizona charter schools were more ethnically segregated than traditional public schools by studying 55 urban and 57 rural charter schools. Nearly half showed evidence of substantial ethnic segregation, and charter schools were higher in white enrollment than other public schools. (SLD)

Metropolitan racial residential segregation and cardiovascular mortality: exploring pathways.

PubMed

Greer, Sophia; Kramer, Michael R; Cook-Smith, Jessica N; Casper, Michele L

2014-06-01

Racial residential segregation has been associated with an increased risk for heart disease and stroke deaths. However, there has been little research into the role that candidate mediating pathways may play in the relationship between segregation and heart disease or stroke deaths. In this study, we examined the relationship between metropolitan statistical area (MSA)-level segregation and heart disease and stroke mortality rates, by age and race, and also estimated the effects of various educational, economic, social, and health-care indicators (which we refer to as pathways) on this relationship. We used Poisson mixed models to assess the relationship between the isolation index in 265 U.S. MSAs and county-level (heart disease, stroke) mortality rates. All models were stratified by race (non-Hispanic black, non-Hispanic white), age group (35-64 years, ≥ 65 years), and cause of death (heart disease, stroke). We included each potential pathway in the model separately to evaluate its effect on the segregation-mortality association. Among blacks, segregation was positively associated with heart disease mortality rates in both age groups but only with stroke mortality rates in the older age group. Among whites, segregation was marginally associated with heart disease mortality rates in the younger age group and was positively associated with heart disease mortality rates in the older age group. Three of the potential pathways we explored attenuated relationships between segregation and mortality rates among both blacks and whites: percentage of female-headed households, percentage of residents living in poverty, and median household income. Because the percentage of female-headed households can be seen as a proxy for the extent of social disorganization, our finding that it has the greatest attenuating effect on the relationship between racial segregation and heart disease and stroke mortality rates suggests that social disorganization may play a strong role in the elevated rates of heart disease and stroke found in racially segregated metropolitan areas.

Rapid mass segregation in small stellar clusters

NASA Astrophysics Data System (ADS)

Spera, Mario; Capuzzo-Dolcetta, Roberto

2017-12-01

In this paper we focus our attention on small-to-intermediate N-body systems that are, initially, distributed uniformly in space and dynamically `cool' (virial ratios Q=2T/|Ω| below ˜0.3). In this work, we study the mass segregation that emerges after the initial violent dynamical evolution. At this scope, we ran a set of high precision N-body simulations of isolated clusters by means of HiGPUs, our direct summation N-body code. After the collapse, the system shows a clear mass segregation. This (quick) mass segregation occurs in two phases: the first shows up in clumps originated by sub-fragmentation before the deep overall collapse; this segregation is partly erased during the deep collapse to re-emerge, abruptly, during the second phase, that follows the first bounce of the system. In this second stage, the proper clock to measure the rate of segregation is the dynamical time after virialization, which (for cold and cool systems) may be significantly different from the crossing time evaluated from initial conditions. This result is obtained for isolated clusters composed of stars of two different masses (in the ratio mh/ml=2), at varying their number ratio, and is confirmed also in presence of a massive central object (simulating a black hole of stellar size). Actually, in stellar systems starting their dynamical evolution from cool conditions, the fast mass segregation adds to the following, slow, secular segregation which is collisionally induced. The violent mass segregation is an effect persistent over the whole range of N (128 ≤ N ≤1,024) investigated, and is an interesting feature on the astronomical-observational side, too. The semi-steady state reached after virialization corresponds to a mass segregated distribution function rather than that of equipartition of kinetic energy per unit mass as it should result from violent relaxation.

Integrated schools, segregated curriculum: effects of within-school segregation on adolescent health behaviors and educational aspirations.

PubMed

Walsemann, Katrina M; Bell, Bethany A

2010-09-01

We examined the extent to which within-school segregation, as measured by unevenness in the distribution of Black and White adolescents across levels of the English curriculum (advanced placement-international baccalaureate-honors, general, remedial, or no English), was associated with smoking, drinking, and educational aspirations, which previous studies found are related to school racial/ethnic composition. We analyzed data from wave 1 of the National Longitudinal Study of Adolescent Health, restricting our sample to non-Hispanic Blacks (n=2731) and Whites (n=4158) who from 1994 to 1995 attended high schools that enrolled Black and White students. White female students had higher predicted probabilities of smoking or drinking than did Black female students; the largest differences were in schools with high levels of within-school segregation. Black male students had higher predicted probabilities of high educational aspirations than did White male students in schools with low levels of within-school segregation; this association was attenuated for Black males attending schools with moderate or high levels of within-school segregation. Our results provide evidence that within-school segregation may influence both students' aspirations and their behaviors.

Density Functional Theory plus Hubbard U Study of the Segregation of Pt to the CeO2- x Grain Boundary.

PubMed

Zhou, Guoli; Li, Pan; Ma, Qingmin; Tian, Zhixue; Liu, Ying

2018-03-14

Grain boundaries (GBs) can be used as traps for solute atoms and defects, and the interaction between segregants and GBs is crucial for understanding the properties of nanocrystalline materials. In this study, we have systematically investigated the Pt segregation and Pt-oxygen vacancies interaction at the ∑3 (111) GB in ceria (CeO 2 ). The Pt atom has a stronger tendency to segregate to the ∑3 (111) GB than to the (111) and (110) free surfaces, but the tendency is weaker than to (112) and (100). Lattice distortion plays a dominant role in Pt segregation. At the Pt-segregated-GB (Pt@GB), oxygen vacancies prefer to form spontaneously near Pt in the GB region. However, at the pristine GB, oxygen vacancies can only form under O-poor conditions. Thus, Pt segregation to the GB promotes the formation of oxygen vacancies, and their strong interactions enhance the interfacial cohesion. We propose that GBs fabricated close to the surfaces of nanocrystalline ceria can trap Pt from inside the grains or other types of surface, resulting in the suppression of the accumulation of Pt on the surface under redox reactions, especially under O-poor conditions.

Residential Segregation by Occupation and Race in Ten Urbanized Areas, 1950-1970.

ERIC Educational Resources Information Center

Simkus, Albert A.

1978-01-01

This study is directed at measuring the changes in residential segregation in ten United States urbanized areas during the 1950s and 1960s. Changes in the relationship between racial and occupational residential segregation are also examined. (Author/EB)

Structurally Integrated Versus Structurally Segregated Memory Representations: Implications for the Design of Instructional Materials.

ERIC Educational Resources Information Center

Hayes-Roth, Barbara

Two kinds of memory organization are distinguished: segregrated versus integrated. In segregated memory organizations, related learned propositions have separate memory representations. In integrated memory organizations, memory representations of related propositions share common subrepresentations. Segregated memory organizations facilitate…

28 CFR 541.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... disposition following the hearing required by § 541.15 before the UDC. (d) Segregation Review Official (SRO). The term Segregation Review Official refers to the individual at each Bureau of Prisons institution assigned to review the status of each inmate housed in disciplinary segregation and administrative...

76 FR 2705 - Notice of Realty Action; Modification of the Segregative Effect of Recreation and Public Purposes...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-14

... action will modify the segregation to open the lands only to effect this exchange. FOR FURTHER... lease on November 3, 1978, and published in the Federal Register (62 FR 9446) which included segregation...

Race and Education: A Review Essay.

ERIC Educational Resources Information Center

Wieder, Alan

1994-01-01

This review essay extends the thesis of Douglas Massey and Nancy Denton, that the continuing cause of the underclass is neighborhood segregation, to cover school segregation. Continuing costs of school segregation, racial tension and white racism, and reinvestment in school integration are also explored. (SLD)

A method for evaluating the relation between sound source segregation and masking

PubMed Central

Lutfi, Robert A.; Liu, Ching-Ju

2011-01-01

Sound source segregation refers to the ability to hear as separate entities two or more sound sources comprising a mixture. Masking refers to the ability of one sound to make another sound difficult to hear. Often in studies, masking is assumed to result from a failure of segregation, but this assumption may not always be correct. Here a method is offered to identify the relation between masking and sound source segregation in studies and an example is given of its application. PMID:21302979

A Victim of Halide Ion Segregation. How Light Soaking Affects Solar Cell Performance of Mixed Halide Lead Perovskites

DOE PAGES

Samu, Gergely F.; Janaky, Csaba; Kamat, Prashant V.

2017-07-24

Photoinduced segregation in mixed halide perovskites has a direct influence on decreasing the solar cell efficiency as segregated I-rich domains serve as charge recombination centers. Here, the changes in the external quantum efficiency mirror the spectral loss in the absorption; however, the time scale of the IPCE recovery in the dark is slower than the absorption recovery, showing the intricate nature of the photoinduced halide segregation and charge collection in solar cell devices.

Process for the physical segregation of minerals

DOEpatents

Yingling, Jon C.; Ganguli, Rajive

2004-01-06

With highly heterogeneous groups or streams of minerals, physical segregation using online quality measurements is an economically important first stage of the mineral beneficiation process. Segregation enables high quality fractions of the stream to bypass processing, such as cleaning operations, thereby reducing the associated costs and avoiding the yield losses inherent in any downstream separation process. The present invention includes various methods for reliably segregating a mineral stream into at least one fraction meeting desired quality specifications while at the same time maximizing yield of that fraction.

A highly efficient measure of mass segregation in star clusters

NASA Astrophysics Data System (ADS)

Olczak, C.; Spurzem, R.; Henning, Th.

2011-08-01

Context. Investigations of mass segregation are of vital interest for the understanding of the formation and dynamical evolution of stellar systems on a wide range of spatial scales. A consistent analysis requires a robust measure among different objects and well-defined comparison with theoretical expectations. Various methods have been used for this purpose but usually with limited significance, quantifiability, and application to both simulations and observations. Aims: We aim at developing a measure of mass segregation with as few parameters as possible, robustness against peculiar configurations, independence of mass determination, simple implementation, stable algorithm, and that is equally well adoptable for data from either simulations or observations. Methods: Our method is based on the minimum spanning tree (MST) that serves as a geometry-independent measure of concentration. Compared to previous such approaches we obtain a significant refinement by using the geometrical mean as an intermediate-pass. Results: The geometrical mean boosts the sensitivity compared to previous applications of the MST. It thus allows the detection of mass segregation with much higher confidence and for much lower degrees of mass segregation than other approaches. The method shows in particular very clear signatures even when applied to small subsets of the entire population. We confirm with high significance strong mass segregation of the five most massive stars in the Orion nebula cluster (ONC). Conclusions: Our method is the most sensitive general measure of mass segregation so far and provides robust results for both data from simulations and observations. As such it is ideally suited for tracking mass segregation in young star clusters and to investigate the long standing paradigm of primordial mass segregation by comparison of simulations and observations.

Neighborhood-Level Racial/Ethnic Residential Segregation and Incident Cardiovascular Disease: The Multi-Ethnic Study of Atherosclerosis

PubMed Central

Kershaw, Kiarri N.; Osypuk, Theresa L.; Do, D. Phuong; De Chavez, Peter J.; Roux, Ana V. Diez

2014-01-01

Background Previous research suggests neighborhood-level racial/ethnic residential segregation is linked to health, but it has not been studied prospectively in relation to cardiovascular disease (CVD). Methods and Results Participants were 1,595 non-Hispanic Black, 2,345 non-Hispanic White, and 1,289 Hispanic adults from the Multi-Ethnic Study of Atherosclerosis free of CVD at baseline (ages 45-84). Own-group racial/ethnic residential segregation was assessed using the Gi∗ statistic, a measure of how the neighborhood racial/ethnic composition deviates from surrounding counties’ racial/ethnic composition. Multivariable Cox proportional hazards modeling was used to estimate hazard ratios (HR) for incident CVD (first definite angina, probable angina followed by revascularization, myocardial infarction, resuscitated cardiac arrest, CHD death, stroke, or stroke death) over 10.2 median years of follow-up. Among Blacks, each standard deviation increase in Black segregation was associated with a 12% higher hazard of developing CVD after adjusting for demographics (95% Confidence Interval (CI): 1.02, 1.22). This association persisted after adjustment for neighborhood-level characteristics, individual socioeconomic position, and CVD risk factors (HR: 1.12; 95% CI: 1.02, 1.23). For Whites, higher White segregation was associated with lower CVD risk after adjusting for demographics (HR: 0.88; 95% CI: 0.81, 0.96), but not after further adjustment for neighborhood characteristics. Segregation was not associated with CVD risk among Hispanics. Similar results were obtained after adjusting for time-varying segregation and covariates. Conclusions The association of residential segregation with cardiovascular risk varies according to race/ethnicity. Further work is needed to better characterize the individual- and neighborhood-level pathways linking segregation to CVD risk. PMID:25447044

Figure-ground segregation requires two distinct periods of activity in V1: a transcranial magnetic stimulation study.

PubMed

Heinen, Klaartje; Jolij, Jacob; Lamme, Victor A F

2005-09-08

Discriminating objects from their surroundings by the visual system is known as figure-ground segregation. This process entails two different subprocesses: boundary detection and subsequent surface segregation or 'filling in'. In this study, we used transcranial magnetic stimulation to test the hypothesis that temporally distinct processes in V1 and related early visual areas such as V2 or V3 are causally related to the process of figure-ground segregation. Our results indicate that correct discrimination between two visual stimuli, which relies on figure-ground segregation, requires two separate periods of information processing in the early visual cortex: one around 130-160 ms and the other around 250-280 ms.

Future directions in research on institutional and interpersonal discrimination and children's health.

PubMed

Acevedo-Garcia, Dolores; Rosenfeld, Lindsay E; Hardy, Erin; McArdle, Nancy; Osypuk, Theresa L

2013-10-01

Research evidence indicates that 2 forms of racial discrimination-perceived interpersonal discrimination and racial/ethnic residential segregation (a form of institutional discrimination)-may influence children's health and disparities. Although research on these 2 forms of discrimination and health has primarily focused on adults, smaller bodies of work have documented that perceived interpersonal discrimination and segregation have a negative effect on infants' health, and that perceived interpersonal discrimination may negatively affect children's mental health. Three directions for research are (1) incorporating a life-course perspective into studies of discrimination and children's health, (2) linking residential segregation with geography-of-opportunity conceptual frameworks and measures, and (3) considering residential segregation along with segregation in other contexts that influence children's health (e.g., schools).

Distribution Behavior of B and P during Al-Si Melt Directional Solidification with Open-Ended Crucible

NASA Astrophysics Data System (ADS)

Bai, Xiaolong; Ban, Boyuan; Li, Jingwei; Peng, Zhijian; Chen, Jian

2018-03-01

Distribution behavior of B and P during directional solidification of Al-20Si, Al-30Si and Al-40Si alloys has been investigated. Macrostructure of the Al-Si alloy ingots and concentration profile of elements B and P reveal that the elements segregate to eutectic Al-Si melt during growth of primary Si flakes, and P gradually segregates to the top of the ingots during directional solidification. An apparent segregation coefficient, ka, is introduced to describe the segregation behavior of B and P between the primary Si and the Al-Si melt and compared with thermodynamic theoretical equilibrium coefficients. The apparent segregation coefficients of B and P decrease with increase of solidification temperature.

The bacterial segrosome: a dynamic nucleoprotein machine for DNA trafficking and segregation.

PubMed

Hayes, Finbarr; Barillà, Daniela

2006-02-01

The genomes of unicellular and multicellular organisms must be partitioned equitably in coordination with cytokinesis to ensure faithful transmission of duplicated genetic material to daughter cells. Bacteria use sophisticated molecular mechanisms to guarantee accurate segregation of both plasmids and chromosomes at cell division. Plasmid segregation is most commonly mediated by a Walker-type ATPase and one of many DNA-binding proteins that assemble on a cis-acting centromere to form a nucleoprotein complex (the segrosome) that mediates intracellular plasmid transport. Bacterial chromosome segregation involves a multipartite strategy in which several discrete protein complexes potentially participate. Shedding light on the basis of genome segregation in bacteria could indicate new strategies aimed at combating pathogenic and antibiotic-resistant bacteria.

Occupational Segregation by Sex: Determinants and Changes.

ERIC Educational Resources Information Center

Beller, Andrea H.

1982-01-01

This study found that occupational sex segregation began to diminish during the 1970s, in conjunction with enforcement of the equal employment opportunity laws against sex discrimination in employment. The success of these laws suggests that discrimination was originally a determinant of occupational segregation. (Author/SK)

Occupational Segregation by Sex: Trends and Prospects.

ERIC Educational Resources Information Center

Blau, Francine D.; Hendricks, Wallace E.

1979-01-01

Investigates postwar trends in occupational segregation. Finds segregation increased slightly between 1950-60 as predominantly female clerical/professional jobs increased. Occupation mix changes (1960-70) were neutral in impact, but male inflow into female professions and female inflow into male sales/clerical jobs produced modest segregation…

17 CFR 32.6 - Segregation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Segregation. 32.6 Section 32.6 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION REGULATION OF COMMODITY OPTION TRANSACTIONS § 32.6 Segregation. (a) Any person which accepts money, securities, or property from an option...

17 CFR 32.6 - Segregation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Segregation. 32.6 Section 32.6 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION REGULATION OF COMMODITY OPTION TRANSACTIONS § 32.6 Segregation. (a) Any person which accepts money, securities, or property from an option...

A Demonstration of Sample Segregation

ERIC Educational Resources Information Center

Fritz, Mark D.; Brumbach, Stephen B.; Hartman, JudithAnn R.

2005-01-01

The demonstration of sample segregation, which is simple, and visually compelling illustrates the importance of sample handling for students studying analytical chemistry and environmental chemistry. The mixture used in this demonstration has two components, which have big particle size, and different colors, which makes the segregation graphic.

First-Principles Study of Mo Segregation in MoNi(111): Effects of Chemisorbed Atomic Oxygen

PubMed Central

Yu, Yanlin; Xiao, Wei; Wang, Jianwei; Wang, Ligen

2015-01-01

Segregation at metal alloy surfaces is an important issue because many electrochemical and catalytic properties are directly correlated to the surface composition. We have performed density functional theory calculations for Mo segregation in MoNi(111) in the presence of chemisorbed atomic oxygen. In particular, the coverage dependence and possible adsorption-induced segregation phenomena are addressed by investigating segregation energies of the Mo atom in MoNi(111). The theoretical calculated results show that the Mo atom prefers to be embedded in the bulk for the clean MoNi(111), while it segregates to the top-most layer when the oxygen coverage is thicker than 1/9 monolayer (ML). Furthermore, we analyze the densities of states for the clean and oxygen-chemisorbed MoNi(111), and see a strong covalent bonding between Mo d-band states and O p-states. The present study provides valuable insight for exploring practical applications of Ni-based alloys as hydrogen evolution electrodes. PMID:28787811

Thermodynamic and kinetic modeling of grain boundary equilibrium segregation of P in α-Fe

DOE PAGES

Yang, Y.; Chen, S. -L.

2017-04-18

Phosphorus is a primary contributor to interface fracture and embrittlement in steels because of its strong segregation tendency at grain boundaries (GBs). The lack of consistency in literature data imposes great difficulties in performing segregation modeling that is compatible with both the Langmuir-Mclean segregation theory and the thermodynamic description of the Bcc(Fe,P) phase. Our work carefully evaluated experimental data for phosphorus segregation at GBs in -Fe and provided a new formula for converting the auger electron spectroscopy (AES) peak height ratio to GBs. Furthermore, based on newly assessed literature data, this work proposes that the major driving force for phosphorusmore » segregation is the formation of Fe 3P-type clusters at GBs, which is supported not only by the almost equivalent Gibbs energy of _Fe using the Bcc(Fe,P) substitutional model and the Bcc(Fe,Fe 3P, P) associate model, but also by the good agreement between thermodynamic/kinetic modeling results and experimental data.« less

[Study on the mode of inheritance for familial polycystic ovary syndrome].

PubMed

Mao, W; Li, M; Chen, Y; Lu, C; Wang, Y; Zhang, X; Qiao, J; Wang, A

2001-02-01

To investigate the mode of inheritance of polycystic ovary syndrome(PCOS). The first female relatives with irregular cycle and the first male relatives with premature balding in each nuclear family were designated the affected. Their prevalence rates in families were respectively calculated. Analyses of segregation ratio were carried out among 139 nuclear families with PCOS by the methods of simple segregation and complex segregation of genetic epidemiology, respectively. The prevalence rates of irregular cycle among mothers and sisters with PCOS were 37.4% and 33.1% respectively, and the prevalence rates of premature balding among fathers and brothers of patients were 19.4% and 6.5%, respectively. The simple segregation analysis indicated that the segregation ratio of PCOS trait in siblings was 0.3023, the complex segregation analysis indicated that it fitted in with the inheritance model of co-dominant disorder with full penetrance and sporadic cases. The frequency of homozygote of disease gene in population was 0.046. PCOS presents the mode of co-dominant inheritance with complete penetrance.

Grain boundary phase transformations in PtAu and relevance to thermal stabilization of bulk nanocrystalline metals

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

O’Brien, C. J.; Barr, C. M.; Price, P. M.

There has recently been a great deal of interest in employing immiscible solutes to stabilize nanocrystalline microstructures. Existing modeling efforts largely rely on mesoscale Monte Carlo approaches that employ a simplified model of the microstructure and result in highly homogeneous segregation to grain boundaries. However, there is ample evidence from experimental and modeling studies that demonstrates segregation to grain boundaries is highly non-uniform and sensitive to boundary character. This work employs a realistic nanocrystalline microstructure with experimentally relevant global solute concentrations to illustrate inhomogeneous boundary segregation. Furthermore, experiments quantifying segregation in thin films are reported that corroborate the prediction thatmore » grain boundary segregation is highly inhomogeneous. In addition to grain boundary structure modifying the degree of segregation, the existence of a phase transformation between low and high solute content grain boundaries is predicted. In order to conduct this study, new embedded atom method interatomic potentials are developed for Pt, Au, and the PtAu binary alloy.« less

Inclusion flotation-driven channel segregation in solidifying steels

PubMed Central

Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

2014-01-01

Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

The time course of perceptual grouping: the role of segregation and shape formation.

PubMed

Razpurker-Apfeld, Irene; Kimchi, Ruth

2007-07-01

The time course of perceptual grouping was examined in two experiments, using a primed matching task. In different conditions, elements were grouped into columns/rows by common lightness, into a shape (triangle/ arrow or square/cross) by common lightness, and into a shape without segregation of elements. The results showed an early and rapid grouping into columns/rows by common lightness and into a shape when no segregation from other elements was involved. Goodness of shape (i.e., triangle/arrow vs. square/cross) had no influence on how early grouping was evident, but the relatively poorer shapes appeared to consolidate with time. In contrast, grouping into a shape that involved segregation and required resolving figure-ground relations between segregated units, as grouping into a shape by common lightness, consumed time, regardless of shape goodness. These results suggest that the time course of grouping varies as a function of the processes involved in it (e.g., segregation and shape formation) and the conditions prevailing for each process.

Non-random Mis-segregation of Human Chromosomes.

PubMed

Worrall, Joseph Thomas; Tamura, Naoka; Mazzagatti, Alice; Shaikh, Nadeem; van Lingen, Tineke; Bakker, Bjorn; Spierings, Diana Carolina Johanna; Vladimirou, Elina; Foijer, Floris; McClelland, Sarah Elizabeth

2018-06-12

A common assumption is that human chromosomes carry equal chances of mis-segregation during compromised cell division. Human chromosomes vary in multiple parameters that might generate bias, but technological limitations have precluded a comprehensive analysis of chromosome-specific aneuploidy. Here, by imaging specific centromeres coupled with high-throughput single-cell analysis as well as single-cell sequencing, we show that aneuploidy occurs non-randomly following common treatments to elevate chromosome mis-segregation. Temporary spindle disruption leads to elevated mis-segregation and aneuploidy of a subset of chromosomes, particularly affecting chromosomes 1 and 2. Unexpectedly, we find that a period of mitotic delay weakens centromeric cohesion and promotes chromosome mis-segregation and that chromosomes 1 and 2 are particularly prone to suffer cohesion fatigue. Our findings demonstrate that inherent properties of individual chromosomes can bias chromosome mis-segregation and aneuploidy rates, with implications for studies on aneuploidy in human disease. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Grain boundary phase transformations in PtAu and relevance to thermal stabilization of bulk nanocrystalline metals

DOE PAGES

O’Brien, C. J.; Barr, C. M.; Price, P. M.; ...

2017-10-31

There has recently been a great deal of interest in employing immiscible solutes to stabilize nanocrystalline microstructures. Existing modeling efforts largely rely on mesoscale Monte Carlo approaches that employ a simplified model of the microstructure and result in highly homogeneous segregation to grain boundaries. However, there is ample evidence from experimental and modeling studies that demonstrates segregation to grain boundaries is highly non-uniform and sensitive to boundary character. This work employs a realistic nanocrystalline microstructure with experimentally relevant global solute concentrations to illustrate inhomogeneous boundary segregation. Furthermore, experiments quantifying segregation in thin films are reported that corroborate the prediction thatmore » grain boundary segregation is highly inhomogeneous. In addition to grain boundary structure modifying the degree of segregation, the existence of a phase transformation between low and high solute content grain boundaries is predicted. In order to conduct this study, new embedded atom method interatomic potentials are developed for Pt, Au, and the PtAu binary alloy.« less

A longitudinal study of administrative segregation.

PubMed

O'Keefe, Maureen L; Klebe, Kelli J; Metzner, Jeffrey; Dvoskin, Joel; Fellner, Jamie; Stucker, Alysha

2013-01-01

The use of administrative segregation for inmates with and without mental illness has generated considerable criticism. Segregated inmates are locked in single cells for 23 hours per day, are subjected to rigorous security procedures, and have restricted access to programs. In this study, we examined whether inmates in segregation would show greater deterioration over time on psychological symptoms than would comparison offenders. The subjects were male inmates, with and without mental illness, in administrative segregation, general population, or special-needs prison. Subjects completed the Brief Symptom Inventory at regular intervals for one year. Results showed differentiation between groups at the outset and statistically significant but small positive change over time across all groups. All groups showed the same change pattern such that there was not the hypothesized differential change of inmates within administrative segregation. This study advances the empirical research, but replication research is needed to make a better determination of whether and under what conditions harm may or may not occur to inmates in solitary confinement.

Partial segregation of posterior crista and saccular fibers to the nodulus and uvula of the cerebellum in mice, and its development

NASA Technical Reports Server (NTRS)

Maklad, Adel; Fritzsch, Bernd

2003-01-01

The projection of the posterior canal crista and saccular afferents to the cerebellum of embryonic and neonatal mice was investigated using carbocyanine dyes. Anterograde tracing from these two endorgans reveals a partial segregation of these two sets of afferents. The saccule projects predominantly to the uvula, with very minor input to the nodulus. The posterior canal projects mainly to the nodulus and, to a lesser extent, to the uvula. Retrograde tracing from the uvula and nodulus confirms this partial segregation for these two endorgans and extends it to other vestibular endorgans. Uvular injections result in many more labeled fibers in the gravistatic maculae than in the canals' cristae. In contrast, nodular injection reveals many more labeled fibers in the canal cristae than in the gravistatic maculae. This partial segregation may play a role in the information processing in these folia. Our developmental data suggest that the initial segregation at E17 coincides with the formation of the postero-lateral fissure. This embryonic segregation of the primary vestibular mossy fibers to the uvula and nodulus commences long before the maturity of their targets, the granule cells and unipolar brush cells. Thus, the segregation of the primary vestibular projection to the uvula and nodulus does not depend on cues related to the target cells. Rather, the segregation may reflect more global cerebellar patterning mechanisms involving guidance for the vestibular afferent fibers independent of the future target cells.

Texture segregation, surface representation and figure-ground separation.

PubMed

Grossberg, S; Pessoa, L

1998-09-01

A widespread view is that most texture segregation can be accounted for by differences in the spatial frequency content of texture regions. Evidence from both psychophysical and physiological studies indicate, however, that beyond these early filtering stages, there are stages of 3-D boundary segmentation and surface representation that are used to segregate textures. Chromatic segregation of element-arrangement patterns--as studied by Beck and colleagues--cannot be completely explained by the filtering mechanisms previously employed to account for achromatic segregation. An element arrangement pattern is composed of two types of elements that are arranged differently in different image regions (e.g. vertically on top and diagonally on the bottom). FACADE theory mechanisms that have previously been used to explain data about 3-D vision and figure-ground separation are here used to simulate chromatic texture segregation data, including data with equiluminant elements on dark or light homogeneous backgrounds, or backgrounds composed of vertical and horizontal dark or light stripes, or horizontal notched stripes. These data include the fact that segregation of patterns composed of red and blue squares decreases with increasing luminance of the interspaces. Asymmetric segregation properties under 3-D viewing conditions with the equiluminant elements close or far are also simulated. Two key model properties are a spatial impenetrability property that inhibits boundary grouping across regions with non-collinear texture elements and a boundary-surface consistency property that uses feedback between boundary and surface representations to eliminate spurious boundary groupings and separate figures from their backgrounds.

Rapid visual perception of interracial crowds: Racial category learning from emotional segregation.

PubMed

Lamer, Sarah Ariel; Sweeny, Timothy D; Dyer, Michael Louis; Weisbuch, Max

2018-05-01

Drawing from research on social identity and ensemble coding, we theorize that crowd perception provides a powerful mechanism for social category learning. Crowds include allegiances that may be distinguished by visual cues to shared behavior and mental states, providing perceivers with direct information about social groups and thus a basis for learning social categories. Here, emotion expressions signaled group membership: to the extent that a crowd exhibited emotional segregation (i.e., was segregated into emotional subgroups), a visible characteristic (race) that incidentally distinguished emotional subgroups was expected to support categorical distinctions. Participants were randomly assigned to view interracial crowds in which emotion differences between (black vs. white) subgroups were either small (control condition) or large (emotional segregation condition). On each trial, participants saw crowds of 12 faces (6 black, 6 white) for roughly 300 ms and were asked to estimate the average emotion of the entire crowd. After all trials, participants completed a racial categorization task and self-report measure of race essentialism. As predicted, participants exposed to emotional segregation (vs. control) exhibited stronger racial category boundaries and stronger race essentialism. Furthermore, such effects accrued via ensemble coding, a visual mechanism that summarizes perceptual information: emotional segregation strengthened participants' racial category boundaries to the extent that segregation limited participants' abilities to integrate emotion across racial subgroups. Together with evidence that people observe emotional segregation in natural environments, these findings suggest that crowd perception mechanisms support racial category boundaries and race essentialism. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Racial segregation, income inequality, and mortality in US metropolitan areas.

PubMed

Nuru-Jeter, Amani M; LaVeist, Thomas A

2011-04-01

Evidence of the association between income inequality and mortality has been mixed. Studies indicate that growing income inequalities reflect inequalities between, rather than within, racial groups. Racial segregation may play a role. We examine the role of racial segregation on the relationship between income inequality and mortality in a cross-section of US metropolitan areas. Metropolitan areas were included if they had a population of at least 100,000 and were at least 10% black (N = 107). Deaths for the time period 1991-1999 were used to calculate age-adjusted all-cause mortality rates for each metropolitan statistical area (MSA) using direct age-adjustment techniques. Multivariate least squares regression was used to examine associations for the total sample and for blacks and whites separately. Income inequality was associated with lower mortality rates among whites and higher mortality rates among blacks. There was a significant interaction between income inequality and racial segregation. A significant graded inverse income inequality/mortality association was found for MSAs with higher versus lower levels of black-white racial segregation. Effects were stronger among whites than among blacks. A positive income inequality/mortality association was found in MSAs with higher versus lower levels of Hispanic-white segregation. Uncertainty regarding the income inequality/mortality association found in previous studies may be related to the omission of important variables such as racial segregation that modify associations differently between groups. Research is needed to further elucidate the risk and protective effects of racial segregation across groups.

10 CFR 1045.41 - Use of classified addendums.

Code of Federal Regulations, 2014 CFR

2014-01-01

... simplify document handling procedures, document originators should segregate RD or FRD into an addendum whenever practical. When RD or FRD is segregated into an addendum, the originator shall acknowledge the...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged to...

10 CFR 1045.41 - Use of classified addendums.

Code of Federal Regulations, 2012 CFR

2012-01-01

... simplify document handling procedures, document originators should segregate RD or FRD into an addendum whenever practical. When RD or FRD is segregated into an addendum, the originator shall acknowledge the...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged to...

10 CFR 1045.41 - Use of classified addendums.

Code of Federal Regulations, 2011 CFR

2011-01-01

... simplify document handling procedures, document originators should segregate RD or FRD into an addendum whenever practical. When RD or FRD is segregated into an addendum, the originator shall acknowledge the...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged to...

10 CFR 1045.41 - Use of classified addendums.

Code of Federal Regulations, 2013 CFR

2013-01-01

... simplify document handling procedures, document originators should segregate RD or FRD into an addendum whenever practical. When RD or FRD is segregated into an addendum, the originator shall acknowledge the...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged to...

10 CFR 1045.41 - Use of classified addendums.

Code of Federal Regulations, 2010 CFR

2010-01-01

... simplify document handling procedures, document originators should segregate RD or FRD into an addendum whenever practical. When RD or FRD is segregated into an addendum, the originator shall acknowledge the...) When segregation of RD or FRD into an addendum is not practical, document originators are encouraged to...

Losing Ground: School Segregation in Massachuestts

ERIC Educational Resources Information Center

Ayscue, Jennifer B.; Greenberg, Alyssa

2013-01-01

Though once a leader in school integration, Massachusetts has regressed over the last two decades as its students of color have experienced intensifying school segregation. This report investigates trends in school segregation in Massachusetts by examining concentration, exposure, and evenness measures by both race and class. First, the report…

The Dimensions of Residential Segregation.

ERIC Educational Resources Information Center

Massey, Douglas S.; Denton, Nancy A.

1988-01-01

Evaluates 20 potential indicators of residential segregation using census data on Hispanics, Blacks, Asians, and non-Hispanic Whites in 60 U.S. metropolitan areas. Factor-analyzes the results to select a single best indicator for each of five dimensions of residential segregation. Contains 69 references and 22 statistical formulas. (SV)

South by Southwest: Mexican Americans and Segregated Schooling, 1900-1950.

ERIC Educational Resources Information Center

Ruiz, Vicki L.

2001-01-01

Addresses school segregation and Mexican Americans, delineating the institutional nature of segregation "for the cause of Americanization." Discusses "Alvarez v. Lemon Grove School District" and "Mendez v. Westminster," two important legal challenges by Mexican American parents on behalf of their children. Includes a bibliography. (CMK)

Residential Segregation in Texas in 1980.

ERIC Educational Resources Information Center

Hwang, Sean-Shong; Murdock, Steve H.

1982-01-01

Between 1970 and 1980 racial and ethnic segregation for major Texas cities declined for all groups, but declines were small between Anglo and Spanish groups. Segregation is unaffected by variation in size of city, percent of population that is Spanish or Black, or central city status. (Author/AM)

17 CFR 1.32 - Segregated account; daily computation and record.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Segregated account; daily computation and record. 1.32 Section 1.32 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION GENERAL REGULATIONS UNDER THE COMMODITY EXCHANGE ACT Recordkeeping § 1.32 Segregated account...

Multilevel Modeling of Social Segregation

ERIC Educational Resources Information Center

Leckie, George; Pillinger, Rebecca; Jones, Kelvyn; Goldstein, Harvey

2012-01-01

The traditional approach to measuring segregation is based upon descriptive, non-model-based indices. A recently proposed alternative is multilevel modeling. The authors further develop the argument for a multilevel modeling approach by first describing and expanding upon its notable advantages, which include an ability to model segregation at a…

7 CFR 3015.10 - Physical segregation and eligibility.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Physical segregation and eligibility. 3015.10 Section 3015.10 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF....10 Physical segregation and eligibility. Except as provided in § 3015.11, awarding agencies shall not...

7 CFR 3015.10 - Physical segregation and eligibility.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Physical segregation and eligibility. 3015.10 Section 3015.10 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF....10 Physical segregation and eligibility. Except as provided in § 3015.11, awarding agencies shall not...

7 CFR 3015.10 - Physical segregation and eligibility.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Physical segregation and eligibility. 3015.10 Section 3015.10 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF....10 Physical segregation and eligibility. Except as provided in § 3015.11, awarding agencies shall not...

7 CFR 3015.10 - Physical segregation and eligibility.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false Physical segregation and eligibility. 3015.10 Section 3015.10 Agriculture Regulations of the Department of Agriculture (Continued) OFFICE OF THE CHIEF....10 Physical segregation and eligibility. Except as provided in § 3015.11, awarding agencies shall not...

Sex Segregation in Undergraduate Engineering Majors

ERIC Educational Resources Information Center

Litzler, Elizabeth

2010-01-01

Gender inequality in engineering persists in spite of women reaching parity in college enrollments and degrees granted. To date, no analyses of educational sex segregation have comprehensively examined segregation within one discipline. To move beyond traditional methods of studying the long-standing stratification by field of study in higher…

Commentary: Dilemmas of Desegregation

ERIC Educational Resources Information Center

Powers, Jeanne M.

2017-01-01

This article is a commentary on Erica Frankenberg's article, "Assessing Segregation under a New Generation of Controlled Choice Policies." Both school segregation and organized efforts to end segregation have a long and deep history in the United States. The Supreme Court's decision in "Brown v. Board of Education" (1954) has…

Administrative Segregation for Mentally Ill Inmates

ERIC Educational Resources Information Center

O'Keefe, Maureen L.

2007-01-01

Largely the result of prison officials needing to safely and efficiently manage a volatile inmate population, administrative segregation or supermax facilities are criticized as violating basic human needs, particularly for mentally ill inmates. The present study compared Colorado offenders with mental illness (OMIs) to nonOMIs in segregated and…

Coleman Revisited: School Segregation, Peers, and Frog Ponds

ERIC Educational Resources Information Center

Goldsmith, Pat Rubio

2011-01-01

Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…

17 CFR 1.25 - Investment of customer funds.

Code of Federal Regulations, 2010 CFR

2010-04-01

... country to the extent it has balances in segregated accounts owed to its customers denominated in that... the extent it has balances in segregated accounts owed to its clearing member futures commission... section, securities transferred to a customer segregated account pursuant to paragraphs (a)(3)(i) or (a)(3...

7 CFR 58.332 - Segregation of raw material.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Segregation of raw material. 58.332 Section 58.332 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.332 Segregation of raw material. The milk and cream received at the dairy plant shall meet...

7 CFR 58.332 - Segregation of raw material.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 3 2011-01-01 2011-01-01 false Segregation of raw material. 58.332 Section 58.332 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Procedures § 58.332 Segregation of raw material. The milk and cream received at the dairy plant shall meet...

Educational Justice and Socio-Economic Segregation in Schools

ERIC Educational Resources Information Center

Brighouse, Harry

2007-01-01

Sociologists exploring educational injustice often focus on socio-economic segregation as a central measure of injustice. The comprehensive ideal, furthermore, has the idea of socio-economic integration built into it. The current paper argues that socio-economic segregation is valuable only insofar as it serves other, more fundamental values. This…

How Economic Segregation Affects Childrens' Educational Attainment. JCPR Working Paper.

ERIC Educational Resources Information Center

Mayer, Susan

Economic segregation increased in the United States between 1970 and 1990. Three hypotheses suggest that this would affect low-income children's educational attainment. The political economy of school funding predicts that economically segregated school districts reduce the educational attainment of low-income children. Two other hypotheses…

The Emergence of Gender Segregation in Toddler Playgroups.

ERIC Educational Resources Information Center

Serbin, Lisa A.; And Others

1994-01-01

A naturalistic study of toddler playgroups examined factors that might encourage gender segregation. Results revealed that play in same-sex contexts facilitates social interaction, whereas in mixed-sex contexts, play leads to passive social relations. Toddlers who segregated were more behaviorally sex-typed. Preferences for sex-typed toys did not…

Residential Segregation: Challenge to White America.

ERIC Educational Resources Information Center

Denton, Nancy A.

1994-01-01

Examines the problem of residential segregation and demonstrates that it is a problem of social structure. The author contends that residential segregation has affirmed the continued subordination of blacks in American society over the past 50 years. New leadership in the Department of Housing and Urban Development is viewed as a positive…

Are There Ethnic Enclaves/Ghettos in English Cities?

ERIC Educational Resources Information Center

Johnston, Ron; Forrest, James; Poulsen, Michael

2002-01-01

Examines residential segregation of urban ethnic groups, identifying residential area types according to the degree of ethnic mixing and evaluating their relative importance in 18 English cities in light of research on processes and patterns involved in segregation. Results find little evidence of significant segregation of black groups but some…

46 CFR 111.60-9 - Segregation of vital circuits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Segregation of vital circuits. 111.60-9 Section 111.60-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-9 Segregation of vital circuits. (a) General. A...

27 CFR 24.191 - Segregation of operations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Segregation of operations. 24.191 Section 24.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Effervescent Wine § 24.191 Segregation of operations...

43 CFR 2091.1 - Action on applications and mining claims.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Segregation and Opening of Lands § 2091.1 Action on applications and mining claims. (a) Except where the law... lessee exclusive use of the lands; (4) Classifications existing under appropriate law: (5) Segregation due to an application previously filed under appropriate law and regulations; (6) Segregation...

Segregation and Civic Virtue

ERIC Educational Resources Information Center

Merry, Michael S.

2012-01-01

In this essay Michael Merry defends the following prima facie argument: that civic virtue is not dependent on integration and in fact may be best fostered under conditions of segregation. He demonstrates that civic virtue can and does take place under conditions of involuntary segregation, but that voluntary separation--as a response to…

The Cumulative Disadvantages of First- and Second-Generation Segregation for Middle School Achievement

ERIC Educational Resources Information Center

Mickelson, Roslyn Arlin

2015-01-01

Middle schools are important because they launch students on trajectories that they are likely to follow throughout their formal educations. This study explored the relationship of first-generation segregation (elementary and middle school racial composition) and second-generation segregation (racially correlated academic tracks) to reading and…

Seeing Race: Teaching Residential Segregation with the Racial Dot Map

ERIC Educational Resources Information Center

Seguin, Charles; Nierobisz, Annette; Kozlowski, Karen Phelan

2017-01-01

Students commonly hold erroneous notions of a "post-racial" world and individualistic worldviews that discount the role of structure in social outcomes. Jointly, these two preconceived beliefs can be powerful barriers to effective teaching of racial segregation: Students may be skeptical that racial segregation continues to exist, and…

77 FR 24220 - Notice of Segregation and Possible Conveyance of Federally Owned Mineral Interests Application...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-23

... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLWY9210000, L54100000.FR0000, WYW180014] Notice of Segregation and Possible Conveyance of Federally Owned Mineral Interests Application; Wyoming AGENCY: Bureau of Land Management, Interior. ACTION: Notice. SUMMARY: This notice segregates the...

27 CFR 24.191 - Segregation of operations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Segregation of operations. 24.191 Section 24.191 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Production of Effervescent Wine § 24.191 Segregation of operations...

46 CFR 111.60-9 - Segregation of vital circuits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Segregation of vital circuits. 111.60-9 Section 111.60-9 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-9 Segregation of vital circuits. (a) General. A...

46 CFR 151.13-5 - Cargo segregation-tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... through design. (2) Segregation of cargo space from machinery spaces and other spaces which have or could... Grade E Liquid (if compatible with cargo) is satisfactory. (b) [Reserved] (c) If a cofferdam is required...

46 CFR 151.13-5 - Cargo segregation-tanks.

Code of Federal Regulations, 2010 CFR

2010-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... design. (2) Segregation of cargo space from machinery spaces and other spaces which have or could have a... separating medium. ii=Double bulkhead, required. Cofferdam, empty tank, pumproom, tank with Grade E Liquid...

46 CFR 151.13-5 - Cargo segregation-tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... design. (2) Segregation of cargo space from machinery spaces and other spaces which have or could have a... separating medium. ii=Double bulkhead, required. Cofferdam, empty tank, pumproom, tank with Grade E Liquid...

46 CFR 151.13-5 - Cargo segregation-tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... design. (2) Segregation of cargo space from machinery spaces and other spaces which have or could have a... separating medium. ii=Double bulkhead, required. Cofferdam, empty tank, pumproom, tank with Grade E Liquid...

46 CFR 151.13-5 - Cargo segregation-tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... CARRYING BULK LIQUID HAZARDOUS MATERIAL CARGOES Cargo Segregation § 151.13-5 Cargo segregation—tanks. (a... through design. (2) Segregation of cargo space from machinery spaces and other spaces which have or could... Grade E Liquid (if compatible with cargo) is satisfactory. (b) [Reserved] (c) If a cofferdam is required...

Desegregation, Unitary Status and Vouchers.

ERIC Educational Resources Information Center

Van Patten, James J.; Shircliffe, Barbara

This paper discusses how trends in school racial desegregation suggest a move back toward segregation. Courts are more willing now to attribute these patterns of racial segregation to demographic changes in residential housing markets rather than to past vestiges of the segregated system as they had done in the past. School officials and community…

9 CFR 149.5 - Offsite identification and segregation of certified swine.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of certified swine. 149.5 Section 149.5 Animals and Animal Products ANIMAL AND PLANT HEALTH... § 149.5 Offsite identification and segregation of certified swine. Certified swine moved from a..., collection point, or slaughter facility, must remain segregated from noncertified swine at all times and...

9 CFR 149.5 - Offsite identification and segregation of certified swine.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of certified swine. 149.5 Section 149.5 Animals and Animal Products ANIMAL AND PLANT HEALTH... § 149.5 Offsite identification and segregation of certified swine. Certified swine moved from a..., collection point, or slaughter facility, must remain segregated from noncertified swine at all times and...

9 CFR 149.5 - Offsite identification and segregation of certified swine.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of certified swine. 149.5 Section 149.5 Animals and Animal Products ANIMAL AND PLANT HEALTH... § 149.5 Offsite identification and segregation of certified swine. Certified swine moved from a..., collection point, or slaughter facility, must remain segregated from noncertified swine at all times and...

9 CFR 149.5 - Offsite identification and segregation of certified swine.

Code of Federal Regulations, 2011 CFR

2011-01-01

... of certified swine. 149.5 Section 149.5 Animals and Animal Products ANIMAL AND PLANT HEALTH... § 149.5 Offsite identification and segregation of certified swine. Certified swine moved from a..., collection point, or slaughter facility, must remain segregated from noncertified swine at all times and...

9 CFR 149.5 - Offsite identification and segregation of certified swine.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of certified swine. 149.5 Section 149.5 Animals and Animal Products ANIMAL AND PLANT HEALTH... § 149.5 Offsite identification and segregation of certified swine. Certified swine moved from a..., collection point, or slaughter facility, must remain segregated from noncertified swine at all times and...

The Impact of School Choice and Public Policy on Segregation: Evidence from Chile

ERIC Educational Resources Information Center

Elacqua, Gregory

2012-01-01

Advocates argue that vouchers can make improved educational opportunity available to disadvantaged students. Critics contend that vouchers increase the risk of stratification. Researchers have found that Chile's voucher program has lead to increased socioeconomic school segregation. What has been overlooked, however, is segregation between schools…

Class, Kinship Density, and Conjugal Role Segregation.

ERIC Educational Resources Information Center

Hill, Malcolm D.

1988-01-01

Studied conjugal role segregation in 150 married women from intact families in working-class community. Found that, although involvement in dense kinship networks was associated with conjugal role segregation, respondents' attitudes toward marital roles and phase of family cycle when young children were present were more powerful predictors of…

Bayesian linkage and segregation analysis: factoring the problem.

PubMed

Matthysse, S

2000-01-01

Complex segregation analysis and linkage methods are mathematical techniques for the genetic dissection of complex diseases. They are used to delineate complex modes of familial transmission and to localize putative disease susceptibility loci to specific chromosomal locations. The computational problem of Bayesian linkage and segregation analysis is one of integration in high-dimensional spaces. In this paper, three available techniques for Bayesian linkage and segregation analysis are discussed: Markov Chain Monte Carlo (MCMC), importance sampling, and exact calculation. The contribution of each to the overall integration will be explicitly discussed.

SIMPLE MODEL OF ICE SEGREGATION USING AN ANALYTIC FUNCTION TO MODEL HEAT AND SOIL-WATER FLOW.

USGS Publications Warehouse

Hromadka, T.V.; Guymon, G.L.

1984-01-01

This paper reports on the development of a simple two-dimensional model of coupled heat and soil-water flow in freezing or thawing soil. The model also estimates ice-segregation (frost-heave) evolution. Ice segregation in soil results from water drawn into a freezing zone by hydraulic gradients created by the freezing of soil-water. Thus, with a favorable balance between the rate of heat extraction and the rate of water transport to a freezing zone, segregated ice lenses may form.

Correlates of figure-ground segregation in fMRI.

PubMed

Skiera, G; Petersen, D; Skalej, M; Fahle, M

2000-01-01

We investigated which correlates of figure-ground-segregation can be detected by means of functional magnetic resonance imaging (fMRI). Five subjects were scanned with a Siemens Vision 1.5 T system. Motion, colour, and luminance-defined checkerboards were presented with alternating control conditions containing one of the two features of the checkerboard. We find a segregation-specific activation in V1 for all subjects and all stimuli and conclude that neural mechanisms exist as early as in the primary visual cortex that are sensitive to figure-ground segregation.

Accurate diblock copolymer phase boundaries at strong segregations

NASA Astrophysics Data System (ADS)

Matsen, M. W.; Whitmore, M. D.

1996-12-01

We examine the lamellar/cylinder and cylinder/sphere phase boundaries for strongly segregated diblock copolymer melts using self-consistent-field theory (SCFT) and the standard Gaussian chain model. Calculations are performed with and without the conventional unit-cell approximation (UCA). We find that for strongly segregated melts, the UCA simply produces a small constant shift in each of the phase boundaries. Furthermore, the boundaries are found to be linear at strong segregations when plotted versus (χN)-1, which allows for accurate extrapolations to χN=∞. Our calculations using the UCA allow direct comparisons to strong-segregation theory (SST), which is accepted as the χN=∞ limit of SCFT. A significant discrepancy between the SST and SCFT results indicate otherwise, suggesting that the present formulation of SST is incomplete.

Radial particle-size segregation during packing of particulates into cylindrical containers

USGS Publications Warehouse

Ripple, C.D.; James, R.V.; Rubin, J.

1973-01-01

In a series of experiments, soil materials were placed in long cylindrical containers, using various packing procedures. Soil columns produced by deposition and simultaneous vibratory compaction were dense and axially uniform, but showed significant radial segregation of particle sizes. Similar results were obtained with deposition and simultaneous impact-type compaction when the impacts resulted in significant container "bouncing". The latter procedure, modified to minimize "bouncing" produced dense, uniform soil columns, showing little radial particle-size segregation. Other procedures tested (deposition alone and deposition followed by compaction) did not result in radial segregation, but produced columns showing either relatively low or axially nonuniform densities. Current data suggest that radial particle-size segregation is mainly due to vibration-induced particle circulation in which particles of various sizes have different circulation rates and paths. ?? 1973.

Surface Segregation Energies of BCC Binaries from Ab Initio and Quantum Approximate Calculations

NASA Technical Reports Server (NTRS)

Good, Brian S.

2003-01-01

We compare dilute-limit segregation energies for selected BCC transition metal binaries computed using ab initio and quantum approximate energy method. Ab initio calculations are carried out using the CASTEP plane-wave pseudopotential computer code, while quantum approximate results are computed using the Bozzolo-Ferrante-Smith (BFS) method with the most recent parameterization. Quantum approximate segregation energies are computed with and without atomistic relaxation. The ab initio calculations are performed without relaxation for the most part, but predicted relaxations from quantum approximate calculations are used in selected cases to compute approximate relaxed ab initio segregation energies. Results are discussed within the context of segregation models driven by strain and bond-breaking effects. We compare our results with other quantum approximate and ab initio theoretical work, and available experimental results.

Segregated Systems of Human Brain Networks.

PubMed

Wig, Gagan S

2017-12-01

The organization of the brain network enables its function. Evaluation of this organization has revealed that large-scale brain networks consist of multiple segregated subnetworks of interacting brain areas. Descriptions of resting-state network architecture have provided clues for understanding the functional significance of these segregated subnetworks, many of which correspond to distinct brain systems. The present report synthesizes accumulating evidence to reveal how maintaining segregated brain systems renders the human brain network functionally specialized, adaptable to task demands, and largely resilient following focal brain damage. The organizational properties that support system segregation are harmonious with the properties that promote integration across the network, but confer unique and important features to the brain network that are central to its function and behavior. Copyright © 2017 Elsevier Ltd. All rights reserved.

Auditory stream segregation in children with Asperger syndrome

PubMed Central

Lepistö, T.; Kuitunen, A.; Sussman, E.; Saalasti, S.; Jansson-Verkasalo, E.; Nieminen-von Wendt, T.; Kujala, T.

2009-01-01

Individuals with Asperger syndrome (AS) often have difficulties in perceiving speech in noisy environments. The present study investigated whether this might be explained by deficient auditory stream segregation ability, that is, by a more basic difficulty in separating simultaneous sound sources from each other. To this end, auditory event-related brain potentials were recorded from a group of school-aged children with AS and a group of age-matched controls using a paradigm specifically developed for studying stream segregation. Differences in the amplitudes of ERP components were found between groups only in the stream segregation conditions and not for simple feature discrimination. The results indicated that children with AS have difficulties in segregating concurrent sound streams, which ultimately may contribute to the difficulties in speech-in-noise perception. PMID:19751798

Residential Segregation and the Availability of Primary Care Physicians

PubMed Central

Gaskin, Darrell J; Dinwiddie, Gniesha Y; Chan, Kitty S; McCleary, Rachael R

2012-01-01

Objective To examine the association between residential segregation and geographic access to primary care physicians (PCPs) in metropolitan statistical areas (MSAs). Data Sources We combined zip code level data on primary care physicians from the 2006 American Medical Association master file with demographic, socioeconomic, and segregation measures from the 2000 U.S. Census. Our sample consisted of 15,465 zip codes located completely or partially in an MSA. Methods We defined PCP shortage areas as those zip codes with no PCP or a population to PCP ratio of >3,500. Using logistic regressions, we estimated the association between a zip code's odds of being a PCP shortage area and its minority composition and degree of segregation in its MSA. Principal Findings We found that odds of being a PCP shortage area were 67 percent higher for majority African American zip codes but 27 percent lower for majority Hispanic zip codes. The association varied with the degree of segregation. As the degree of segregation increased, the odds of being a PCP shortage area increased for majority African American zip codes; however, the converse was true for majority Hispanic and Asian zip codes. Conclusions Efforts to address PCP shortages should target African American communities especially in segregated MSAs. PMID:22524264

Racial segregation in postbellum Southern cities: The case of Washington, D.C.

PubMed Central

Logan, John R.

2018-01-01

BACKGROUND Segregation in Southern cities has been described as a 20th-century development, layered onto an earlier pattern in which whites and blacks (both slaves and free black people) shared the same neighborhoods. Urban historians have pointed out ways in which the Southern postbellum pattern was less benign, but studies relying on census data aggregated by administrative areas – and segregation measures based on this data – have not confirmed their observations. METHODS This study is based mainly on 100% microdata from the 1880 census that has been mapped at the address level in Washington, D.C. This data makes it possible to examine in detail the unique spatial configuration of segregation that is found in this city, especially the pattern of housing in alleys. RESULTS While segregation appears to have been low, as reflected in data by wards and even by much smaller enumeration districts, analyses at a finer spatial scale reveal strongly patterned separation between blacks and whites at this early time. CONTRIBUTION This research provides much new information about segregation in a major Southern city at the end of the 19th century. It also demonstrates the importance of dealing explicitly with issues of both scale and spatial pattern in studies of segregation. PMID:29375269

Single Vesicle Analysis of Endocytic Fission on Microtubules In Vitro

PubMed Central

Wolkoff, Allan W.

2016-01-01

Following endocytosis, internalized molecules are found within intracellular vesicles and tubules that move along the cytoskeleton and undergo fission, as demonstrated here using primary cultured rat hepatocytes. Although the use of depolymerizing drugs has shown that the cytoskeleton is not required to segregate endocytic protein, many studies suggest that the cytoskeleton is involved in the segregation of protein in normal cells. To investigate whether cytoskeletal-based movement results in the segregation of protein, we tracked the contents of vesicles during in vitro microscopy assays. These studies showed that the addition of ATP causes fission of endocytic contents along microtubules, resulting in the segregation of proteins that are targeted for different cellular compartments. The plasma membrane proteins, sodium (Na+) taurocholate cotransporting polypeptide (ntcp) and transferrin receptor, segregated from asialoorosomucoid (ASOR), an endocytic ligand that is targeted for degradation. Epidermal growth factor receptor, which is degraded, and the asialoglycoprotein receptor, which remains partially bound to ASOR, segregated less efficiently from ASOR. Vesicles containing ntcp and transferrin receptor had reduced fission in the absence of ASOR, suggesting that fission is regulated to allow proteins to segregate. A single round of fission resulted in 6.5-fold purification of ntcp from ASOR, and 25% of the resulting vesicles were completely depleted of the endocytic ligand. PMID:18284582

Prior Knowledge Guides Speech Segregation in Human Auditory Cortex.

PubMed

Wang, Yuanye; Zhang, Jianfeng; Zou, Jiajie; Luo, Huan; Ding, Nai

2018-05-18

Segregating concurrent sound streams is a computationally challenging task that requires integrating bottom-up acoustic cues (e.g. pitch) and top-down prior knowledge about sound streams. In a multi-talker environment, the brain can segregate different speakers in about 100 ms in auditory cortex. Here, we used magnetoencephalographic (MEG) recordings to investigate the temporal and spatial signature of how the brain utilizes prior knowledge to segregate 2 speech streams from the same speaker, which can hardly be separated based on bottom-up acoustic cues. In a primed condition, the participants know the target speech stream in advance while in an unprimed condition no such prior knowledge is available. Neural encoding of each speech stream is characterized by the MEG responses tracking the speech envelope. We demonstrate that an effect in bilateral superior temporal gyrus and superior temporal sulcus is much stronger in the primed condition than in the unprimed condition. Priming effects are observed at about 100 ms latency and last more than 600 ms. Interestingly, prior knowledge about the target stream facilitates speech segregation by mainly suppressing the neural tracking of the non-target speech stream. In sum, prior knowledge leads to reliable speech segregation in auditory cortex, even in the absence of reliable bottom-up speech segregation cue.

Energetics of vacancy segregation to [100] symmetric tilt grain boundaries in bcc tungsten

PubMed Central

Chen, Nanjun; Niu, Liang-Liang; Zhang, Ying; Shu, Xiaolin; Zhou, Hong-Bo; Jin, Shuo; Ran, Guang; Lu, Guang-Hong; Gao, Fei

2016-01-01

The harsh irradiation environment poses serious threat to the structural integrity of leading candidate for plasma-facing materials, tungsten (W), in future nuclear fusion reactors. It is thus essential to understand the radiation-induced segregation of native defects and impurities to defect sinks, such as grain boundaries (GBs), by quantifying the segregation energetics. In this work, molecular statics simulations of a range of equilibrium and metastable [100] symmetric tilt GBs are carried out to explore the energetics of vacancy segregation. We show that the low-angle GBs have larger absorption length scales over their high-angle counterparts. Vacancy sites that are energetically unfavorable for segregation are found in all GBs. The magnitudes of minimum segregation energies for the equilibrium GBs vary from −2.61 eV to −0.76 eV depending on the GB character, while those for the metastable GB states tend to be much lower. The significance of vacancy delocalization in decreasing the vacancy segregation energies and facilitating GB migration has been discussed. Metrics such as GB energy and local stress are used to interpret the simulation results, and correlations between them have been established. This study contributes to the possible application of polycrystalline W under irradiation in advanced nuclear fusion reactors. PMID:27874047

Effect of Co-segregating Markers on High-Density Genetic Maps and Prediction of Map Expansion Using Machine Learning Algorithms.

PubMed

N'Diaye, Amidou; Haile, Jemanesh K; Fowler, D Brian; Ammar, Karim; Pozniak, Curtis J

2017-01-01

Advances in sequencing and genotyping methods have enable cost-effective production of high throughput single nucleotide polymorphism (SNP) markers, making them the choice for linkage mapping. As a result, many laboratories have developed high-throughput SNP assays and built high-density genetic maps. However, the number of markers may, by orders of magnitude, exceed the resolution of recombination for a given population size so that only a minority of markers can accurately be ordered. Another issue attached to the so-called 'large p, small n' problem is that high-density genetic maps inevitably result in many markers clustering at the same position (co-segregating markers). While there are a number of related papers, none have addressed the impact of co-segregating markers on genetic maps. In the present study, we investigated the effects of co-segregating markers on high-density genetic map length and marker order using empirical data from two populations of wheat, Mohawk × Cocorit (durum wheat) and Norstar × Cappelle Desprez (bread wheat). The maps of both populations consisted of 85% co-segregating markers. Our study clearly showed that excess of co-segregating markers can lead to map expansion, but has little effect on markers order. To estimate the inflation factor (IF), we generated a total of 24,473 linkage maps (8,203 maps for Mohawk × Cocorit and 16,270 maps for Norstar × Cappelle Desprez). Using seven machine learning algorithms, we were able to predict with an accuracy of 0.7 the map expansion due to the proportion of co-segregating markers. For example in Mohawk × Cocorit, with 10 and 80% co-segregating markers the length of the map inflated by 4.5 and 16.6%, respectively. Similarly, the map of Norstar × Cappelle Desprez expanded by 3.8 and 11.7% with 10 and 80% co-segregating markers. With the increasing number of markers on SNP-chips, the proportion of co-segregating markers in high-density maps will continue to increase making map expansion unavoidable. Therefore, we suggest developers improve linkage mapping algorithms for efficient analysis of high-throughput data. This study outlines a practical strategy to estimate the IF due to the proportion of co-segregating markers and outlines a method to scale the length of the map accordingly.

Effect of Co-segregating Markers on High-Density Genetic Maps and Prediction of Map Expansion Using Machine Learning Algorithms

PubMed Central

N’Diaye, Amidou; Haile, Jemanesh K.; Fowler, D. Brian; Ammar, Karim; Pozniak, Curtis J.

2017-01-01

Advances in sequencing and genotyping methods have enable cost-effective production of high throughput single nucleotide polymorphism (SNP) markers, making them the choice for linkage mapping. As a result, many laboratories have developed high-throughput SNP assays and built high-density genetic maps. However, the number of markers may, by orders of magnitude, exceed the resolution of recombination for a given population size so that only a minority of markers can accurately be ordered. Another issue attached to the so-called ‘large p, small n’ problem is that high-density genetic maps inevitably result in many markers clustering at the same position (co-segregating markers). While there are a number of related papers, none have addressed the impact of co-segregating markers on genetic maps. In the present study, we investigated the effects of co-segregating markers on high-density genetic map length and marker order using empirical data from two populations of wheat, Mohawk × Cocorit (durum wheat) and Norstar × Cappelle Desprez (bread wheat). The maps of both populations consisted of 85% co-segregating markers. Our study clearly showed that excess of co-segregating markers can lead to map expansion, but has little effect on markers order. To estimate the inflation factor (IF), we generated a total of 24,473 linkage maps (8,203 maps for Mohawk × Cocorit and 16,270 maps for Norstar × Cappelle Desprez). Using seven machine learning algorithms, we were able to predict with an accuracy of 0.7 the map expansion due to the proportion of co-segregating markers. For example in Mohawk × Cocorit, with 10 and 80% co-segregating markers the length of the map inflated by 4.5 and 16.6%, respectively. Similarly, the map of Norstar × Cappelle Desprez expanded by 3.8 and 11.7% with 10 and 80% co-segregating markers. With the increasing number of markers on SNP-chips, the proportion of co-segregating markers in high-density maps will continue to increase making map expansion unavoidable. Therefore, we suggest developers improve linkage mapping algorithms for efficient analysis of high-throughput data. This study outlines a practical strategy to estimate the IF due to the proportion of co-segregating markers and outlines a method to scale the length of the map accordingly. PMID:28878789

Residential Ethnic Segregation and Stroke Risk in Mexican Americans: The Brain Attack Surveillance in Corpus Christi Project

PubMed Central

Patel, Rajiv C; Baek, Jonggyu; Smith, Melinda A; Morgenstern, Lewis B; Lisabeth, Lynda D

2015-01-01

Objective Residential ethnic segregation may operate through multiple mechanisms to increase stroke risk. The current study evaluated if residential ethnic segregation was associated with stroke risk in a bi-ethnic population. Design Incident strokes were identified in Nueces County, Texas from 2000 to 2010. Residential ethnic segregation (range: 0–1) was derived for each census tract in the county (n=64) using 2000 U.S Census data, and categorized into: predominantly non-Hispanic white (NHW, <0.3); ethnically mixed (0.3–0.7); predominantly Mexican American (MA, >0.7). Multilevel Poisson regression models were fitted separately for NHWs and MAs to assess the association between residential ethnic segregation (predominantly NHW referent) and relative risk for stroke, adjusted for age category, sex and census tract-level median per capita income. Effect modification by age was also examined. Results In adjusted models, residential ethnic segregation was not associated with stroke risk in either ethnic group. Effect modification by age was significant in both groups. Young MAs and NHWs living in predominantly MA census tracts were at greater relative risk for stroke than those living in predominantly NHW census tracts, but this association was only significant for MAs [MAs: RR = 2.38 (95% CI: 1.31–4.31); NHWs: RR = 1.53 (95% CI: 0.92–2.52)]. Conclusion Our findings demonstrate that residential ethnic segregation may influence downstream stroke risk in young MAs. Pathways between residential ethnic segregation and stroke in young MAs should be explored. PMID:25812246

Brain network segregation and integration during an epoch-related working memory fMRI experiment.

PubMed

Fransson, Peter; Schiffler, Björn C; Thompson, William Hedley

2018-05-17

The characterization of brain subnetwork segregation and integration has previously focused on changes that are detectable at the level of entire sessions or epochs of imaging data. In this study, we applied time-varying functional connectivity analysis together with temporal network theory to calculate point-by-point estimates in subnetwork segregation and integration during an epoch-based (2-back, 0-back, baseline) working memory fMRI experiment as well as during resting-state. This approach allowed us to follow task-related changes in subnetwork segregation and integration at a high temporal resolution. At a global level, the cognitively more taxing 2-back epochs elicited an overall stronger response of integration between subnetworks compared to the 0-back epochs. Moreover, the visual, sensorimotor and fronto-parietal subnetworks displayed characteristic and distinct temporal profiles of segregation and integration during the 0- and 2-back epochs. During the interspersed epochs of baseline, several subnetworks, including the visual, fronto-parietal, cingulo-opercular and dorsal attention subnetworks showed pronounced increases in segregation. Using a drift diffusion model we show that the response time for the 2-back trials are correlated with integration for the fronto-parietal subnetwork and correlated with segregation for the visual subnetwork. Our results elucidate the fast-evolving events with regard to subnetwork integration and segregation that occur in an epoch-related task fMRI experiment. Our findings suggest that minute changes in subnetwork integration are of importance for task performance. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Sex- and Gamete-Specific Patterns of X Chromosome Segregation in a Trioecious Nematode.

PubMed

Tandonnet, Sophie; Farrell, Maureen C; Koutsovoulos, Georgios D; Blaxter, Mark L; Parihar, Manish; Sadler, Penny L; Shakes, Diane C; Pires-daSilva, Andre

2018-01-08

Three key steps in meiosis allow diploid organisms to produce haploid gametes: (1) homologous chromosomes (homologs) pair and undergo crossovers; (2) homologs segregate to opposite poles; and (3) sister chromatids segregate to opposite poles. The XX/XO sex determination system found in many nematodes [1] facilitates the study of meiosis because variation is easily recognized [2-4]. Here we show that meiotic segregation of X chromosomes in the trioecious nematode Auanema rhodensis [5] varies according to sex (hermaphrodite, female, or male) and type of gametogenesis (oogenesis or spermatogenesis). In this species, XO males exclusively produce X-bearing sperm [6, 7]. The unpaired X precociously separates into sister chromatids, which co-segregate with the autosome set to generate a functional haplo-X sperm. The other set of autosomes is discarded into a residual body. Here we explore the X chromosome behavior in female and hermaphrodite meioses. Whereas X chromosomes segregate following the canonical pattern during XX female oogenesis to yield haplo-X oocytes, during XX hermaphrodite oogenesis they segregate to the first polar body to yield nullo-X oocytes. Thus, crosses between XX hermaphrodites and males yield exclusively male progeny. During hermaphrodite spermatogenesis, the sister chromatids of the X chromosomes separate during meiosis I, and homologous X chromatids segregate to the functional sperm to create diplo-X sperm. Given these intra-species, intra-individual, and intra-gametogenesis variations in the meiotic program, A. rhodensis is an ideal model for studying the plasticity of meiosis and how it can be modulated. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

77 FR 67042 - Self-Regulatory Organizations; The Options Clearing Corporation; Notice of No Objection to...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-08

... Amendment No. 1 Thereto, Relating to the Margining of Segregated Futures Customer Accounts on a Gross Basis... of Filing of Proposed Rule Change Relating to the Margining of Segregated Futures Customer Accounts...\\ ``Advance Notice Relating to the Margining of Segregated Futures Customer Accounts on a Gross Basis...

Assessing Residential Segregation among Medicaid Recipients with Psychiatric Disability in Philadelphia

ERIC Educational Resources Information Center

Metraux, Stephen; Caplan, Joel M.; Klugman, Dutch; Hadley, Trevor R.

2007-01-01

This study assesses the extent of residential segregation among 15,246 people diagnosed with psychiatric disabilities and receiving Medicaid (MA) in Philadelphia, and an identically sized group of MA recipients serving as matched controls. Results indicate that overall levels of residential segregation among this group were modest at their most…

New Jersey's Segregated Schools: Trends and Paths Forward

ERIC Educational Resources Information Center

Orfield, Gary; Ee, Jongyeon; Coughlan, Ryan

2017-01-01

This report updates earlier research published by the Civil Rights Project in 2013. That report detailed troubling racial and economic segregation trends and patterns from 1989-2010. The latest report includes new data from 2010-2015. The research updates public school enrollment trends and details segregation in the state's schools by race and…

A Return to the "Mexican Room": The Segregation of Arizona's English Learners

ERIC Educational Resources Information Center

Gandara, Patricia; Orfield, Gary

2010-01-01

This paper reviews the research on the impact of segregation on Latino and English Language Learner (ELL) students, including new empirical research conducted in Arizona. It also reviews court decisions regarding students' rights to be integrated with their mainstream peers, and provides data on the increasing segregation of Arizona's Latino and…

"Brown" at 62: School Segregation by Race, Poverty and State

ERIC Educational Resources Information Center

Orfield, Gary; Ee, Jongyeon; Frankenberg, Erica; Siegel-Hawley, Genevieve

2016-01-01

As the anniversary of "Brown v. Board of Education" decision arrives again without any major initiatives to mitigate spreading and deepening segregation in the nation's schools, the Civil Rights Project adds to a growing national discussion with a research brief drawn from a much broader study of school segregation to be published in…

17 CFR 1.23 - Interest of futures commission merchant in segregated futures customer funds; additions and...

Code of Federal Regulations, 2014 CFR

2014-04-01

... any and all futures customers' accounts from becoming undersegregated at any time. (2) If a futures commission merchant discovers at any time that it is holding insufficient funds in segregated accounts to... with the segregated funds requirements at all times. Each futures commission merchant shall establish...

Show Me: Diversity and Isolation Indicators of Spatial Segregation within and across Missouri's School Districts

ERIC Educational Resources Information Center

Tate, William F.; Hogrebe, Mark C.

2018-01-01

Our study examines patterns of spatial segregation using diversity and isolation indicators within and across Missouri school districts. Evaluating segregation from a critical spatial perspective emphasizes the importance of place when evaluating the quality of educational opportunity for diverse student populations. The methodology involves the…

PROGRESS AND PROBLEMS FROM THE SOCIAL SCIENTIST'S VIEWPOINT.

ERIC Educational Resources Information Center

CLARK, KENNETH

REVIEWED FROM A SOCIAL SCIENTIST'S VIEWPOINT IS THE EFFECT OF THE SUPREME COURT'S 1954 BROWN DECISION ON PATTERNS OF DEFACTO SEGREGATION IN NORTHERN COMMUNITIES. THE DECISION HAD PROFOUND EFFECTS ON DE FACTO SEGREGATION, PARTICULARLY IN RELATION TO THE DEMOCRATIC IDEALS OF EQUALITY AND TO THE DAMAGED SELF-IMAGE CREATED BY SEGREGATED SCHOOLS. IT…

RACIAL ISOLATION IN THE PUBLIC SCHOOLS, VOLUME 1.

ERIC Educational Resources Information Center

HANNAH, JOHN A.; AND OTHERS

THE FINDINGS OF A STUDY OF RACIAL ISOLATION IN THE PUBLIC SCHOOLS ARE DISCUSSED. THE STUDY FOCUSED ON (1) THE EXTENT OF RACIAL SEGREGATION IN THE SCHOOLS AND THE DISPARITY BETWEEN THE EDUCATIONAL ACHIEVEMENT OF NEGRO AND WHITE SCHOOL CHILDREN, (2) FACTORS WHICH INTENSIFY AND PERPETUATE SEGREGATION, (3) THE EFFECTS OF SEGREGATED SCHOOLING ON…

Auditory Stream Segregation in Autism Spectrum Disorder: Benefits and Downsides of Superior Perceptual Processes

ERIC Educational Resources Information Center

Bouvet, Lucie; Mottron, Laurent; Valdois, Sylviane; Donnadieu, Sophie

2016-01-01

Auditory stream segregation allows us to organize our sound environment, by focusing on specific information and ignoring what is unimportant. One previous study reported difficulty in stream segregation ability in children with Asperger syndrome. In order to investigate this question further, we used an interleaved melody recognition task with…

A sexy spin on nonrandom chromosome segregation.

PubMed

Charville, Gregory W; Rando, Thomas A

2013-06-06

Nonrandom chromosome segregation is an intriguing phenomenon linked to certain asymmetric stem cell divisions. In a recent report in Nature, Yadlapalli and Yamashita (2013) observe nonrandom segregation of X and Y chromosomes in Drosophila germline stem cells and shed light on the complex mechanisms of this fascinating process. Copyright © 2013 Elsevier Inc. All rights reserved.

Engaging Suburban Students in Dialogues on Diversity in a Segregated Metropolitan Area

ERIC Educational Resources Information Center

Checkoway, Barry; Lipa, Todd; Vivyan, Erika; Zurvalec, Sue

2017-01-01

What are some strategies for engaging suburban students in dialogues on diversity in new American metropolis? This question is important, especially at a time when some suburbs are changing from "segregated" to "segregated and diverse," and scholarship is needed to guide their discussion. This article analyzes efforts by a…

Residential Segregation and Birth Weight among Racial and Ethnic Minorities in the United States

ERIC Educational Resources Information Center

Walton, Emily

2009-01-01

Racial and ethnic minorities are often residentially segregated from whites in urban settings, a fact which has important health consequences. Research on the relationship between residential segregation and health outcomes lacks national-level investigation of racial and ethnic minority groups other than African Americans. I use multilevel…

Antecedents of Toddler Gender Segregation: Cognitive Consonance, Gender-Typed Toy Preferences and Behavioral Compatibility.

ERIC Educational Resources Information Center

Moller, Lora C.; Serbin, Lisa A.

1996-01-01

Possible antecedents of toddler gender separation were studied with 57 toddlers with a mean age of 35 months. There were no differences between gender-segregating and nonsegregating children regarding gender toy preferences or gender awareness, but teachers saw gender-segregating girls as more socially sensitive. (SLD)

Educational Leadership and Racism: A Narrative Inquiry into Second-Generation Segregation

ERIC Educational Resources Information Center

Brooks, Jeffrey; Arnold, Noelle Witherspoon; Brooks, Melanie C.

2013-01-01

Background/Context: In-school racial segregation, also called second-generation segregation, is a social dynamic that is manifest in different and complicated ways in schoolhouses across the United States. This study sought to investigate how building-level leadership facilitates or impedes the practice of racial equity in an urban high school,…

Learning Apart, Living Apart: How the Racial and Ethnic Segregation of Schools and Colleges Perpetuates Residential Segregation

ERIC Educational Resources Information Center

Goldsmith, Pat Rubio

2010-01-01

Background: Despite a powerful civil rights movement and legislation barring discrimination in housing markets, residential neighborhoods remain racially segregated. Purpose: This study examines the extent to which neighborhoods' racial composition is inherited across generations and the extent to which high schools' and colleges' racial…

Racial Transformation and the Changing Nature of Segregation

ERIC Educational Resources Information Center

Orfield, Gary; Lee, Chungmei

2006-01-01

This report is about the changing patterns of segregation in American public schools through the 2003-2004 school year. It begins by examining the transformation of racial composition in the nation's schools, the dynamic patterns of segregation and desegregation of all racial groups in regions, states, and districts by using data from 1968 until…

Standardized Testing and School Segregation: Like Tinder for Fire?

ERIC Educational Resources Information Center

Knoester, Matthew; Au, Wayne

2017-01-01

Recent research suggests that high-stakes standardized testing has played a negative role in the segregation of children by race and class in schools. In this article we review research on the overall effects of segregation, the positive and negative aspects of how desegregation plans were carried out following the 1954 Supreme Court decision…

Women's Work, Men's Work. Sex Segregation on the Job.

ERIC Educational Resources Information Center

Reskin, Barbara F., Ed.; Hartmann, Heidi I., Ed.

The literature on sex segregation in the workplace was reviewed to determine how it could be used in formulating policy in the area of sex fairness in the American labor market. The committee found that although women's occupational options have increased dramatically in the past decade, sex segregation is still widespread. Among those factors…

10 CFR 9.19 - Segregation of exempt information and deletion of identifying details.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 1 2011-01-01 2011-01-01 false Segregation of exempt information and deletion of identifying details. 9.19 Section 9.19 Energy NUCLEAR REGULATORY COMMISSION PUBLIC RECORDS Freedom of Information Act Regulations § 9.19 Segregation of exempt information and deletion of identifying details. (a...

9 CFR 354.123 - Segregation of suspects on ante-mortem inspection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Segregation of suspects on ante-mortem inspection. 354.123 Section 354.123 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Inspection Procedures; Ante-Mortem Inspections § 354.123 Segregation of suspects on ante-mortem inspection...

10 CFR 9.19 - Segregation of exempt information and deletion of identifying details.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Segregation of exempt information and deletion of identifying details. 9.19 Section 9.19 Energy NUCLEAR REGULATORY COMMISSION PUBLIC RECORDS Freedom of Information Act Regulations § 9.19 Segregation of exempt information and deletion of identifying details. (a...

36 CFR 1275.46 - Segregation and review; Senior Archival Panel; Presidential Materials Review Board.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 3 2011-07-01 2011-07-01 false Segregation and review; Senior Archival Panel; Presidential Materials Review Board. 1275.46 Section 1275.46 Parks, Forests, and... Access by the Public § 1275.46 Segregation and review; Senior Archival Panel; Presidential Materials...

77 FR 52080 - Self-Regulatory Organizations; The Depository Trust Company; Notice of Filing and Immediate...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-28

... by failure of Participants to move their shares from their segregation account to their general free... free account to its segregation account.\\5\\ This causes a short position in the Participant's general... to the Participant's free account instead of the Participant's segregation account. \\5\\ The Sub...

Introduction to the Issue on Segregation, Desegregation, and Integration: From History, to Policy, to Practice

ERIC Educational Resources Information Center

Diem, Sarah; Brooks, Jeffrey

2013-01-01

The articles in this special issue examine the increasingly complex relationship between segregation, desegregation, and integration in a sociopolitical environment vastly different from that of the initial days of desegregation. These issues are examined from historical and political perspectives, contextualizing the complexities of segregation,…

43 CFR 2091.3-2 - Opening.

Code of Federal Regulations, 2011 CFR

2011-10-01

... OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of... segregation period set out in § 2091.3-1 of this part. (b) If the proposal or application described in § 2091.3-1 of this part is denied, modified, or otherwise terminated prior to the end of the segregation...

9 CFR 354.123 - Segregation of suspects on ante-mortem inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Segregation of suspects on ante-mortem inspection. 354.123 Section 354.123 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... Inspection Procedures; Ante-Mortem Inspections § 354.123 Segregation of suspects on ante-mortem inspection...

Women into Non-Traditional Sectors: Addressing Gender Segregation in the Northern Ireland Workplace

ERIC Educational Resources Information Center

Potter, Michael; Hill, Myrtle

2009-01-01

The horizontal segregation of the workforce along gender lines tends to assign women to lower paid, lower status employment. Consequently, schemes to address segregation have focused on preparing women to enter non-traditional occupations through training and development processes. This article examines models to encourage women into…

Forgotten History: Mexican American School Segregation in Arizona from 1900-1951

ERIC Educational Resources Information Center

Powers, Jeanne M.

2008-01-01

This article documents the efforts by Mexican Americans to challenge school segregation in Arizona in the first half of the twentieth century. As in Texas and California, although state law never formally mandated the segregation of Mexican American students, school districts in Arizona often established separate "Mexican Schools" for…

A Comparative Analysis of Black and Mexican American Residential Segregation in Southwestern Cities.

ERIC Educational Resources Information Center

Meier, Michael; Feagin, Joe

Discrimination, poverty, and ethnic attachment or choice have been identified as 3 factors that might explain residential segregation. This paper purported: (1) to comparatively document the nature and extent of metropolitan segregation of Mexican Americans and Blacks in the Southwest; (2) to perform an exploratory analysis of the significance of…

Segregation in Gay, Lesbian and Bisexual Youth's Personal Networks: Testing Structural Constraint, Choice Homophily and Compartmentalization Hypotheses

ERIC Educational Resources Information Center

Ueno, Koji; Wright, Eric R.; Gayman, Mathew D.; McCabe, Janice M.

2012-01-01

Homophily promotes the development of social relationships within social groups and increases segregation across groups. Although prior research has demonstrated that network segregation operates in many dimensions such as race and gender, sexual orientation has received little attention. This study investigates what accounts for the segregation…

Should Educators and Parents Encourage Other-Gender Interactions? Gender Segregation and Sexism

ERIC Educational Resources Information Center

Keener, Emily; Mehta, Clare; Strough, JoNell

2013-01-01

We investigated gender differences in the association between gender-segregated peer preferences and sexism in adolescents (15-17 years, 60 boys and 85 girls). To assess gender-segregated peer preferences, adolescents nominated peers for interaction in two contexts: "hanging out" at home and working on a school project. The Modern Sexism…

Arab American Residential Segregation: Differences in Patterns.

ERIC Educational Resources Information Center

Parrillo, Vincent N.

In order to determine the extent of residential segregation among first or second generation Arabs living in and around Paterson, New Jersey, 286 families were located and interviewed. Field data were combined with statistics from the U.S. Census Bureau Population and Housing Summary Tape File 1-A. It was found that residential segregation was not…

43 CFR 2462.4 - Segregative effect of publication.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregative effect of publication. 2462.4... Disposal Classification Procedure: Over 2,560 Acres § 2462.4 Segregative effect of publication. (a) Publication in the Federal Register of a notice of proposed classification pursuant to § 2462.1 or of a notice...

The Shaping of Postcollege Colorblind Orientation among Whites: Residential Segregation and Campus Diversity Experiences

ERIC Educational Resources Information Center

Jayakumar, Uma M.

2015-01-01

In this article, Uma M. Jayakumar investigates the cumulative impact of experiences with segregation or racial diversity prior to and during college on colorblind ideological orientation among white adults. An analysis of longitudinal data spanning ten years reveals that, for whites from segregated and diverse childhood neighborhoods, some…

A New Predictive Model of Centerline Segregation in Continuous Cast Steel Slabs by Using Multivariate Adaptive Regression Splines Approach

PubMed Central

García Nieto, Paulino José; González Suárez, Victor Manuel; Álvarez Antón, Juan Carlos; Mayo Bayón, Ricardo; Sirgo Blanco, José Ángel; Díaz Fernández, Ana María

2015-01-01

The aim of this study was to obtain a predictive model able to perform an early detection of central segregation severity in continuous cast steel slabs. Segregation in steel cast products is an internal defect that can be very harmful when slabs are rolled in heavy plate mills. In this research work, the central segregation was studied with success using the data mining methodology based on multivariate adaptive regression splines (MARS) technique. For this purpose, the most important physical-chemical parameters are considered. The results of the present study are two-fold. In the first place, the significance of each physical-chemical variable on the segregation is presented through the model. Second, a model for forecasting segregation is obtained. Regression with optimal hyperparameters was performed and coefficients of determination equal to 0.93 for continuity factor estimation and 0.95 for average width were obtained when the MARS technique was applied to the experimental dataset, respectively. The agreement between experimental data and the model confirmed the good performance of the latter.

Seasonal sexual segregation in two Thalassarche albatross species: competitive exclusion, reproductive role specialization or foraging niche divergence?

PubMed

Phillips, R A; Silk, J R D; Phalan, B; Catry, P; Croxall, J P

2004-06-22

Sexual segregation by micro- or macrohabitat is common in birds, and usually attributed to size-mediated dominance and exclusion of females by larger males, trophic niche divergence or reproductive role specialization. Our study of black-browed albatrosses, Thalassarche melanophrys, and grey-headed albatrosses, T. chrysostoma, revealed an exceptional degree of sexual segregation during incubation, with largely mutually exclusive core foraging ranges for each sex in both species. Spatial segregation was not apparent during brood-guard or post-guard chick rearing, when adults are constrained to feed close to colonies, providing no evidence for dominance-related competitive exclusion at the macrohabitat level. A comprehensive morphometric comparison indicated considerable species and sexual dimorphism in wing area and wing loading that corresponded, both within and between species, to broad-scale habitat preferences relating to wind strength. We suggest that seasonal sexual segregation in these two species is attributable to niche divergence mediated by differences in flight performance. Such sexual segregation may also have implications for conservation in relation to sex-specific overlap with commercial fisheries.

Importance of sequence specific hydrophobicity in synthetic protein transduction domain mimics.

PubMed

Sgolastra, Federica; Minter, Lisa M; Osborne, Barbara A; Tew, Gregory N

2014-03-10

A new series of synthetic protein transduction domain mimics (PTDMs) was designed to analyze the importance of guanidine and phenyl group segregation along the backbone on their membrane interaction and cellular internalization abilities. ROMP was utilized to synthesize three polymers: nonsegregated homopolymers, intermediately segregated gradient copolymers, and strongly segregated block copolymers. In order to understand the role of functional group segregation on activity, it was important to design monomers that enabled these three different polymer topologies, or constitutional macromolecular isomers, to be prepared with identical chemical compositions. The structure-activity relationships were evaluated by both a biophysical assay, using dye-loaded vesicles, and by in vitro cellular uptake studies of fluorescently labeled chains. The results showed that functional group segregation impacts activity. In general, the nonsegregated homopolymer was the most active in both assays but also showed larger, ill-defined aggregates compared to either the gradient or block copolymers. It was also the most cytotoxic of the three isomers. As a result, the gradient copolymer with intermediate segregation optimizes activity and solubility with low cytotoxicity. This study gives new design guidelines for the development of PTDMs.

Variation of mutational burden in healthy human tissues suggests non-random strand segregation and allows measuring somatic mutation rates.

PubMed

Werner, Benjamin; Sottoriva, Andrea

2018-06-01

The immortal strand hypothesis poses that stem cells could produce differentiated progeny while conserving the original template strand, thus avoiding accumulating somatic mutations. However, quantitating the extent of non-random DNA strand segregation in human stem cells remains difficult in vivo. Here we show that the change of the mean and variance of the mutational burden with age in healthy human tissues allows estimating strand segregation probabilities and somatic mutation rates. We analysed deep sequencing data from healthy human colon, small intestine, liver, skin and brain. We found highly effective non-random DNA strand segregation in all adult tissues (mean strand segregation probability: 0.98, standard error bounds (0.97,0.99)). In contrast, non-random strand segregation efficiency is reduced to 0.87 (0.78,0.88) in neural tissue during early development, suggesting stem cell pool expansions due to symmetric self-renewal. Healthy somatic mutation rates differed across tissue types, ranging from 3.5 × 10-9/bp/division in small intestine to 1.6 × 10-7/bp/division in skin.

DNA asymmetry in stem cells - immortal or mortal?

PubMed

Yadlapalli, Swathi; Yamashita, Yukiko M

2013-09-15

The immortal strand hypothesis proposes that stem cells retain a template copy of genomic DNA (i.e. an 'immortal strand') to avoid replication-induced mutations. An alternative hypothesis suggests that certain cells segregate sister chromatids non-randomly to transmit distinct epigenetic information. However, this area of research has been highly controversial, with conflicting data even from the same cell types. Moreover, historically, the same term of 'non-random sister chromatid segregation' or 'biased sister chromatid segregation' has been used to indicate distinct biological processes, generating a confusion in the biological significance and potential mechanism of each phenomenon. Here, we discuss the models of non-random sister chromatid segregation, and we explore the strengths and limitations of the various techniques and experimental model systems used to study this question. We also describe our recent study on Drosophila male germline stem cells, where sister chromatids of X and Y chromosomes are segregated non-randomly during cell division. We aim to integrate the existing evidence to speculate on the underlying mechanisms and biological relevance of this long-standing observation on non-random sister chromatid segregation.

Uncovering mass segregation with galaxy analogues in dark-matter simulations

NASA Astrophysics Data System (ADS)

Joshi, Gandhali D.; Parker, Laura C.; Wadsley, James

2016-10-01

We investigate mass segregation in group and cluster environments by identifying galaxy analogues in high-resolution dark-matter simulations. Subhaloes identified by the Amiga's Halo Finder (AHF) and ROCKSTAR halo finders have similar mass functions, independent of resolution, but different radial distributions due to significantly different subhalo hierarchies. We propose a simple way to classify subhaloes as galaxy analogues. The radial distributions of galaxy analogues agree well at large halocentric radii for both AHF and ROCKSTAR but disagree near parent halo centres where the phase-space information used by ROCKSTAR is essential. We see clear mass segregation at small radii (within 0.5 rvir) with average galaxy analogue mass decreasing with radius. Beyond the virial radius, we find a mild trend where the average galaxy analogue mass increases with radius. These mass segregation trends are strongest in small groups and dominated by the segregation of low-mass analogues. The lack of mass segregation in massive galaxy analogues suggests that the observed trends are driven by the complex accretion histories of the parent haloes rather than dynamical friction.

Effect of Macrosegregation on the Microstructure and Mechanical Properties of a Pressure-Vessel Steel

NASA Astrophysics Data System (ADS)

Yan, Guanghua; Han, Lizhan; Li, Chuanwei; Luo, Xiaomeng; Gu, Jianfeng

2017-07-01

Macrosegregation refers to the chemical segregation, which occurs quite commonly in the large forgings such as nuclear reactor pressure vessel. This work assesses the effect of macrosegregation and homogenization treatment on the mechanical properties of a pressure-vessel steel (SA508 Gr.3). It was found that the primary reason for the inhomogeneity of the microstructure was the segregation of Mn, Mo, and Ni. Martensite, and coarse upper bainite with M-A (martensite-austenite) islands have been obtained, respectively, in the positive and negative segregation zone during a simulated quenching process. During tempering, the carbon-rich M-A islands decomposed into a mixture of ferrite and numerous carbides which deteriorated the toughness of the material. The segregation has been substantially minimized by a homogenizing treatment. The results indicate that the material homogenized has a higher impact toughness than the material with segregation, due to the reduction in M-A island in the negative segregation zone. It can be concluded that the microstructure and mechanical properties have been improved remarkably by means of homogenization treatment.

Wider-community Segregation and the Effect of Neighbourhood Ethnic Diversity on Social Capital: An Investigation into Intra-Neighbourhood Trust in Great Britain and London

PubMed Central

Laurence, James

2016-01-01

Extensive research has demonstrated that neighbourhood ethnic diversity is negatively associated with intra-neighbourhood social capital. This study explores the role of segregation and integration in this relationship. To do so it applies three-level hierarchical linear models to two sets of data from across Great Britain and within London, and examines how segregation across the wider-community in which a neighbourhood is nested impacts trust amongst neighbours. This study replicates the increasingly ubiquitous finding that neighbourhood diversity is negatively associated with neighbour-trust. However, we demonstrate that this relationship is highly dependent on the level of segregation across the wider-community in which a neighbourhood is nested. Increasing neighbourhood diversity only negatively impacts neighbour-trust when nested in more segregated wider-communities. Individuals living in diverse neighbourhoods nested within integrated wider-communities experience no trust-penalty. These findings show that segregation plays a critical role in the neighbourhood diversity/trust relationship, and that its absence from the literature biases our understanding of how ethnic diversity affects social cohesion. PMID:28989199

Wider-community Segregation and the Effect of Neighbourhood Ethnic Diversity on Social Capital: An Investigation into Intra-Neighbourhood Trust in Great Britain and London.

PubMed

Laurence, James

2017-10-01

Extensive research has demonstrated that neighbourhood ethnic diversity is negatively associated with intra-neighbourhood social capital. This study explores the role of segregation and integration in this relationship. To do so it applies three-level hierarchical linear models to two sets of data from across Great Britain and within London, and examines how segregation across the wider-community in which a neighbourhood is nested impacts trust amongst neighbours. This study replicates the increasingly ubiquitous finding that neighbourhood diversity is negatively associated with neighbour-trust. However, we demonstrate that this relationship is highly dependent on the level of segregation across the wider-community in which a neighbourhood is nested. Increasing neighbourhood diversity only negatively impacts neighbour-trust when nested in more segregated wider-communities. Individuals living in diverse neighbourhoods nested within integrated wider-communities experience no trust-penalty. These findings show that segregation plays a critical role in the neighbourhood diversity/trust relationship, and that its absence from the literature biases our understanding of how ethnic diversity affects social cohesion.

Density Zoning and Class Segregation in U.S. Metropolitan Areas

PubMed Central

Rothwell, Jonathan T.; Massey, Douglas S.

2013-01-01

Objectives Socioeconomic segregation rose substantially in U.S. cities during the final decades of the 20th century and we argue zoning regulations are an important cause for this increase. Methods We measure neighborhood economic segregation using the Gini Coefficient for neighborhood income inequality and the poor-affluent exposure index. These outcomes are regressed on an index of density zoning developed from the work of Pendall for 50 U.S. metropolitan areas, while controlling for other metropolitan characteristics likely to affect urban housing markets and class segregation. Results For both 2000 and changes from 1990 to 2000, OLS estimates reveal a strong relationship between density zoning and income segregation, and replication using 2SLS suggests that the relationship is causal. We also show that zoning is associated with higher inter-jurisdictional inequality. Conclusions Metropolitan areas with suburbs that restrict the density of residential construction are more segregated on the basis of income than those with more permissive density zoning regimes. This arrangement perpetuates and exacerbates racial and class inequality in the United States. PMID:21117332

Mineralogy and origin of coarse-grained segregations in the pyrometallurgical Zn-Pb slags from Katowice-Wełnowiec (Poland)

NASA Astrophysics Data System (ADS)

Warchulski, R.; Gawęda, A.; Janeczek, J.; Kądziołka-Gaweł, M.

2016-10-01

The unique among pyrometallurgical slags, coarse-grained (up to 2.5 cm) segregations (up to 40 cm long) rimmed by "aplitic" border zones occur within holocrystalline historical Zn-smelting slag in Katowice, S Poland. Slag surrounding the segregations consists of olivine, spinel series, melilite, clinopyroxene, leucite, nepheline and sulphides. Ca-olivines, kalsilite and mica compositionally similar to oxykinoshitalite occur in border zones in addition to olivine, spinel series and melilite. Miarolitic and massive pegmatite-like segregations are built of subhedral crystals of melilite, leucite, spinel series, clinopyroxene and hematite. Melilite, clinopyroxenes and spinels in the segregations are enriched in Zn relatively to original slag and to fine-grained border zones. The segregations originated as a result of crystallization from residual melt rich in volatiles (presumably CO2). The volatile-rich melt was separated during fractional crystallization of molten slag under the cover of the overlying hot (ca. 1250 °C) vesicular slag, preventing the escape of volatiles. That unique slag system is analogous to natural magmatic systems.

Why don't segregated Roma do more for their health? An explanatory framework from an ethnographic study in Slovakia.

PubMed

Belak, Andrej; Madarasova Geckova, Andrea; van Dijk, Jitse P; Reijneveld, Sijmen A

2018-06-16

The health status of segregated Roma is poor. To understand why segregated Roma engage in health-endangering practices, we explored their nonadherence to clinical and public health recommendations. We examined one segregated Roma settlement of 260 inhabitants in Slovakia. To obtain qualitative data on local-level mechanisms supporting Roma nonadherence, we combined ethnography and systematic interviewing over 10 years. We then performed a qualitative content analysis based on sociological and public health theories. Our explanatory framework summarizes how the nonadherence of local Roma was supported by an interlocked system of seven mechanisms, controlled by and operating through both local Roma and non-Roma. These regard the Roma situation of poverty, segregation and substandard infrastructure; the Roma socialization into their situation; the Roma-perceived value of Roma alternative practices; the exclusionary non-Roma and self-exclusionary Roma ideologies; the discrimination, racism and dysfunctional support towards Roma by non-Roma; and drawbacks in adherence. Non-Roma ideologies, internalized by Roma into a racialized ethnic identity through socialization, and drawbacks in adherence might present powerful, yet neglected, mechanisms supporting segregated Roma nonadherence.

Suzuki segregation in a binary Cu-Si alloy.

PubMed

Mendis, Budhika G; Jones, Ian P; Smallman, Raymond E

2004-01-01

Suzuki segregation to stacking faults and coherent twin boundaries has been investigated in a Cu-7.15 at.% Si alloy, heat-treated at temperatures of 275, 400 and 550 degrees C, using field-emission gun transmission electron microscopy. Silicon enrichment was observed at the stacking fault plane and decreased monotonically with increasing annealing temperature. This increase in the concentration of solute at the fault is due to the stacking fault energy being lowered at higher values of the electron-to-atom ratio of the alloy. From a McLean isotherm, the binding energy for segregation was calculated to be -0.021 +/- 0.019 eV atom(-1). Hardly any segregation was observed to coherent twin boundaries in the same alloy. This is because a twin has a lower interfacial energy than a stacking fault, so that the driving force for segregation is diminished.

Positive segregation as a function of buoyancy force during steel ingot solidification.

PubMed

Radovic, Zarko; Jaukovic, Nada; Lalovic, Milisav; Tadic, Nebojsa

2008-12-01

We analyze theoretically and experimentally solute redistribution in the dendritic solidification process and positive segregation during solidification of steel ingots. Positive segregation is mainly caused by liquid flow in the mushy zone. Changes in the liquid steel velocity are caused by the temperature gradient and by the increase in the solid fraction during solidification. The effects of buoyancy and of the change in the solid fraction on segregation intensity are analyzed. The relationships between the density change, liquid fraction and the steel composition are considered. Such elements as W, Ni, Mo and Cr decrease the effect of the density variations, i.e. they show smaller tendency to segregate. Based on the modeling and experimental results, coefficients are provided controlling the effects of chemical composition, secondary dendrite arm spacing and the solid fraction.

Housing Tenure and Residential Segregation in Metropolitan America

PubMed Central

Friedman, Samantha; Tsao, Hui-shien; Chen, Cheng

2013-01-01

Homeownership, a symbol of the American dream, is one of the primary ways through which families accumulate wealth, particularly for blacks and Hispanics. Surprisingly, no study has explicitly documented the segregation of minority owners and renters from whites. Using data from Census 2000, this study aims to fill this gap. Analyses here reveal that the segregation of black renters relative to whites is significantly lower than the segregation of black owners from whites, controlling for relevant socioeconomic and demographic factors, contrary to the notion that homeownership represents an endpoint in the residential assimilation process. The patterns for Hispanics and Asians conform more to expectations under the spatial assimilation model. The findings here suggest that race and ethnicity continue to be as important in shaping residential segregation as socioeconomic status, and raise concerns about the benefits of homeownership, particularly for blacks. PMID:23292639

Residential Segregation,Spatial Mismatch and Economic Growth across US Metropolitan Area

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

Campbell, Dr Harrison; Li, Huiping

2013-01-01

Numerous studies have demonstrated the detrimental influence of residential segregation on poor inner-city residents. This study examines the impact of residential segregation on the welfare of populations in US metropolitan areas using economic growth as the indicator. Panel data of US metropolitan areas spanning 25 years, 1980 2005, are used to analyze the effect of segregation on economic growth. The results show that both racial and skill segregation have a negative impact on short and long-term economic growth, which have increased over time. Further, the negative impact of the variables associated with spatial mismatch is also revealed. The results clearlymore » point to the need for mobility policies that favor non-White households and comprehensive strategies that promote economic opportunities in low-resource communities in the US.« less

Birth outcomes among urban African-American women: a multilevel analysis of the role of racial residential segregation.

PubMed

Bell, Janice F; Zimmerman, Frederick J; Almgren, Gunnar R; Mayer, Jonathan D; Huebner, Colleen E

2006-12-01

Residential segregation is a common aspect of the urban experiences of African-Americans in the United States (US), yet few studies have considered how segregation might influence perinatal health. Here, we develop a conceptual model of relationships between segregation and birth outcomes and test the implications of the model in a sample of 434,376 singleton births to African-American women living in 225 US Metropolitan Statistical Areas (MSAs). Data from the National Center for Health Statistics 2002 birth files were linked to data from the 2000 US Census and two distinct measures of segregation: an index of isolation (the probability that an African-American resident will encounter another African-American resident in any random neighborhood encounter) and an index of clustering (the extent to which African-Americans live in contiguous neighborhoods). Using multilevel regression models, controlling for individual- and MSA-level socioeconomic status and other covariates, we found higher isolation was associated with lower birthweight, higher rates of prematurity and higher rates of fetal growth restriction. In contrast, higher clustering was associated with more optimal outcomes. We propose that isolation reflects factors associated with segregation that are deleterious to health including poor neighborhood quality, persistent discrimination and the intra-group diffusion of harmful health behaviors. Associations with clustering may reflect factors associated with segregation that are health-promoting such as African-American political power empowerment, social support and cohesion. Declines in isolation could represent positive steps toward improving birth outcomes among African-American infants while aspects of racial contiguity appear to be mitigating or indeed beneficial. Segregation is a complex multidimensional construct with both deleterious and protective influences on birth outcomes, depending on the dimensions under consideration. Further research to understand racial/ethnic and economic health disparities could benefit from a focus on the contributory role of neighborhood attributes associated with the dimensions segregation and other social geographies.

Sound stream segregation: a neuromorphic approach to solve the “cocktail party problem” in real-time

PubMed Central

Thakur, Chetan Singh; Wang, Runchun M.; Afshar, Saeed; Hamilton, Tara J.; Tapson, Jonathan C.; Shamma, Shihab A.; van Schaik, André

2015-01-01

The human auditory system has the ability to segregate complex auditory scenes into a foreground component and a background, allowing us to listen to specific speech sounds from a mixture of sounds. Selective attention plays a crucial role in this process, colloquially known as the “cocktail party effect.” It has not been possible to build a machine that can emulate this human ability in real-time. Here, we have developed a framework for the implementation of a neuromorphic sound segregation algorithm in a Field Programmable Gate Array (FPGA). This algorithm is based on the principles of temporal coherence and uses an attention signal to separate a target sound stream from background noise. Temporal coherence implies that auditory features belonging to the same sound source are coherently modulated and evoke highly correlated neural response patterns. The basis for this form of sound segregation is that responses from pairs of channels that are strongly positively correlated belong to the same stream, while channels that are uncorrelated or anti-correlated belong to different streams. In our framework, we have used a neuromorphic cochlea as a frontend sound analyser to extract spatial information of the sound input, which then passes through band pass filters that extract the sound envelope at various modulation rates. Further stages include feature extraction and mask generation, which is finally used to reconstruct the targeted sound. Using sample tonal and speech mixtures, we show that our FPGA architecture is able to segregate sound sources in real-time. The accuracy of segregation is indicated by the high signal-to-noise ratio (SNR) of the segregated stream (90, 77, and 55 dB for simple tone, complex tone, and speech, respectively) as compared to the SNR of the mixture waveform (0 dB). This system may be easily extended for the segregation of complex speech signals, and may thus find various applications in electronic devices such as for sound segregation and speech recognition. PMID:26388721

Sound stream segregation: a neuromorphic approach to solve the "cocktail party problem" in real-time.

PubMed

Thakur, Chetan Singh; Wang, Runchun M; Afshar, Saeed; Hamilton, Tara J; Tapson, Jonathan C; Shamma, Shihab A; van Schaik, André

2015-01-01

The human auditory system has the ability to segregate complex auditory scenes into a foreground component and a background, allowing us to listen to specific speech sounds from a mixture of sounds. Selective attention plays a crucial role in this process, colloquially known as the "cocktail party effect." It has not been possible to build a machine that can emulate this human ability in real-time. Here, we have developed a framework for the implementation of a neuromorphic sound segregation algorithm in a Field Programmable Gate Array (FPGA). This algorithm is based on the principles of temporal coherence and uses an attention signal to separate a target sound stream from background noise. Temporal coherence implies that auditory features belonging to the same sound source are coherently modulated and evoke highly correlated neural response patterns. The basis for this form of sound segregation is that responses from pairs of channels that are strongly positively correlated belong to the same stream, while channels that are uncorrelated or anti-correlated belong to different streams. In our framework, we have used a neuromorphic cochlea as a frontend sound analyser to extract spatial information of the sound input, which then passes through band pass filters that extract the sound envelope at various modulation rates. Further stages include feature extraction and mask generation, which is finally used to reconstruct the targeted sound. Using sample tonal and speech mixtures, we show that our FPGA architecture is able to segregate sound sources in real-time. The accuracy of segregation is indicated by the high signal-to-noise ratio (SNR) of the segregated stream (90, 77, and 55 dB for simple tone, complex tone, and speech, respectively) as compared to the SNR of the mixture waveform (0 dB). This system may be easily extended for the segregation of complex speech signals, and may thus find various applications in electronic devices such as for sound segregation and speech recognition.

Effect of Sr Content and Strain on Sr Surface Segregation of La 1–x Sr x Co 0.2 Fe 0.8 O 3-δ as Cathode Material for Solid Oxide Fuel Cells

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

Yu, Yang; Ludwig, Karl F.; Woicik, Joseph C.

2016-10-12

Strontium doped lanthanum cobalt ferrite (LSCF) is a widely used cathode material due to its high electronic and ionic conductivity, and reasonable oxygen surface exchange coefficient. However, LSCF can have long-term stability issues such as surface segregation of Sr during solid oxide fuel cell (SOFC) operation, which can adversely affect the electrochemical performance. Thus, understanding the nature of the Sr surface segregation phenomenon, and how it is affected by the composition of LSCF and strain are critical. In this research, heteroepitaxial thin films of La 1-x Sr xCo 0.2Fe 0.8O 3 - with varying Sr content (x = 0.4, 0.3,more » 0.2) were deposited by pulsed laser deposition (PLD) on single crystal NdGaO 3, SrTiO 3 and GdScO 3 substrates, leading to different levels of strain in the films. The extent of Sr segregation at the film surface was quantified using synchrotron-based total reflection x-ray fluorescence (TXRF), and atomic force microscopy (AFM). The electronic structure of the Sr-rich phases formed on the surface was investigated by hard X-ray photoelectron spectroscopy (HAXPES). The extent of Sr segregation was found to be a function of the Sr content in bulk. Lowering the Sr content from 40% to 30% reduced the surface segregation, but further lowering the Sr content to 20% increased the segregation. The strain of LSCF thin films on various substrates was measured using high-resolution x-ray diffraction (HRXRD) and the Sr surface segregation was found to be reduced with compressive strain and enhanced with tensile strain present within the thin films. A model was developed correlating the Sr surface segregation with Sr content and strain effects to explain the experimental results.« less

Heats of Segregation of BCC Binaries from Ab Initio and Quantum Approximate Calculations

NASA Technical Reports Server (NTRS)

Good, Brian S.

2003-01-01

We compare dilute-limit segregation energies for selected BCC transition metal binaries computed using ab initio and quantum approximate energy methods. Ab initio calculations are carried out using the CASTEP plane-wave pseudopotential computer code, while quantum approximate results are computed using the Bozzolo-Ferrante-Smith (BFS) method with the most recent parameters. Quantum approximate segregation energies are computed with and without atomistic relaxation. Results are discussed within the context of segregation models driven by strain and bond-breaking effects. We compare our results with full-potential quantum calculations and with available experimental results.

Colonic stem cell data are consistent with the immortal model of stem cell division under non-random strand segregation.

PubMed

Walters, K

2009-06-01

Colonic stem cells are thought to reside towards the base of crypts of the colon, but their numbers and proliferation mechanisms are not well characterized. A defining property of stem cells is that they are able to divide asymmetrically, but it is not known whether they always divide asymmetrically (immortal model) or whether there are occasional symmetrical divisions (stochastic model). By measuring diversity of methylation patterns in colon crypt samples, a recent study found evidence in favour of the stochastic model, assuming random segregation of stem cell DNA strands during cell division. Here, the effect of preferential segregation of the template strand is considered to be consistent with the 'immortal strand hypothesis', and explore the effect on conclusions of previously published results. For a sample of crypts, it is shown how, under the immortal model, to calculate mean and variance of the number of unique methylation patterns allowing for non-random strand segregation and compare them with those observed. The calculated mean and variance are consistent with an immortal model that incorporates non-random strand segregation for a range of stem cell numbers and levels of preferential strand segregation. Allowing for preferential strand segregation considerably alters previously published conclusions relating to stem cell numbers and turnover mechanisms. Evidence in favour of the stochastic model may not be as strong as previously thought.

Improving waste segregation while reducing costs in a tertiary-care hospital in a lower-middle-income country in Central America.

PubMed

Johnson, Kyle M; González, Miriam L; Dueñas, Lourdes; Gamero, Mario; Relyea, George; Luque, Laura E; Caniza, Miguela A

2013-07-01

Healthcare waste (HCW) management and segregation are essential to ensure safety, environmental protection and cost control. Poor HCW management increase risks and costs for healthcare institutions. On-going surveillance and training are important to maintain good HCW practices. Our objectives were to evaluate and improve HCW practices at Hospital Bloom, San Salvador, El Salvador. We studied HCW disposal practices by observing waste containers, re-segregating waste placed in biohazardous waste bags, and administering a seven-itemsknowledge survey before and after training in waste management at Hospital Bloom. The training was based on national and international standards. We followed total biohazardous waste production before and after the training. The hospital staff was knowledgeable about waste segregation practices, but had poor compliance with national policies. Re-segregating waste in biohazardous waste bags showed that 61% of this waste was common waste, suggesting that the staff was possibly unaware of the cost of mis-segregating healthcare waste. After staff training in HCW management, the correct responses increased by 44% and biohazardous waste disposal at the hospital reduced by 48%. Better segregation of biohazardous waste and important savings can be obtained by HCW management education of hospital staff. Hospitals can benefit from maximising the use of available resources by sustaining best practices of HCW, especially those in hospitals in lower-middle-income countries.

Residential segregation and the health of African-American infants: does the effect vary by prevalence?

PubMed

Nyarko, Kwame A; Wehby, George L

2012-10-01

Segregation effects may vary between areas (e.g., counties) of low and high low birth weight (LBW; <2,500 g) and preterm birth (PTB; <37 weeks of gestation) rates due to interactions with area differences in risks and resources. We assess whether the effects of residential segregation on county-level LBW and PTB rates for African-American infants vary by the prevalence of these conditions. The study sample includes 368 counties of 100,000 or more residents and at least 50 African-American live births in 2000. Residentially segregated counties are identified alternatively by county-level dissimilarity and isolation indices. Quantile regression is used to assess how residential segregation affects the entire distributions of county-level LBW and PTB rates (i.e. by prevalence). Residential segregation increases LBW and PTB rates significantly in areas of low prevalence, but has no such effects for areas of high prevalence. As a sensitivity analysis, we use metropolitan statistical area level data and obtain similar results. Our findings suggest that residential segregation has adverse effects mainly in areas of low prevalence of LBW and preterm birth, which are expected overall to have fewer risk factors and more resources for infant health, but not in high prevalence areas, which are expected to have more risk factors and fewer resources. Residential policies aimed at area resource improvements may be more effective.

Roosevelt elk density and social segregation: Foraging behavior and females avoiding larger groups of males

USGS Publications Warehouse

Weckerly, F.; McFarland, K.; Ricca, M.; Meyer, K.

2004-01-01

Intersexual social segregation at small spatial scales is prevalent in ruminants that are sexually dimorphic in body size. Explaining social segregation, however, from hypotheses of how intersexual size differences affects the foraging process of males and females has had mixed results. We studied whether body size influences on forage behavior, intersexual social incompatibility or both might influence social segregation in a population of Roosevelt elk (Cervus elaphus roosevelt) that declined 40% over 5 y. Most males and females in the population occurred in the same forage patches, meadows, but occupied different parts of meadows and most groups were overwhelming comprised of one sex. The extent of segregation varied slightly with changing elk density. Cropping rate, our surrogate of forage ingestion, of males in mixed-sex groups differed from males in male-only groups at high, but not low, elk density. In a prior study of intersexual social interactions it was shown that females avoided groups containing ???6 males. Therefore, we predicted that females should avoid parts of meadows where groups of males ???6 were prevalent. Across the 5 y of study this prediction held because ???5% of all females were found in parts of meadows where median aggregation sizes of males were ???6. Social segregation was coupled to body size influences on forage ingestion at high density and social incompatibility was coupled to social segregation regardless of elk density.

Opposing dorsal/ventral stream dynamics during figure-ground segregation.

PubMed

Wokke, Martijn E; Scholte, H Steven; Lamme, Victor A F

2014-02-01

The visual system has been commonly subdivided into two segregated visual processing streams: The dorsal pathway processes mainly spatial information, and the ventral pathway specializes in object perception. Recent findings, however, indicate that different forms of interaction (cross-talk) exist between the dorsal and the ventral stream. Here, we used TMS and concurrent EEG recordings to explore these interactions between the dorsal and ventral stream during figure-ground segregation. In two separate experiments, we used repetitive TMS and single-pulse TMS to disrupt processing in the dorsal (V5/HMT⁺) and the ventral (lateral occipital area) stream during a motion-defined figure discrimination task. We presented stimuli that made it possible to differentiate between relatively low-level (figure boundary detection) from higher-level (surface segregation) processing steps during figure-ground segregation. Results show that disruption of V5/HMT⁺ impaired performance related to surface segregation; this effect was mainly found when V5/HMT⁺ was perturbed in an early time window (100 msec) after stimulus presentation. Surprisingly, disruption of the lateral occipital area resulted in increased performance scores and enhanced neural correlates of surface segregation. This facilitatory effect was also mainly found in an early time window (100 msec) after stimulus presentation. These results suggest a "push-pull" interaction in which dorsal and ventral extrastriate areas are being recruited or inhibited depending on stimulus category and task demands.

Association Between Childhood School Segregation and Changes in Adult Sense of Control in the African American Health Cohort

PubMed Central

2013-01-01

Objective. Cross-sectional associations between childhood school segregation and adult sense of control and physical performance have been established in the African American Health (AAH) cohort. Here we extend that work by estimating the association between childhood school segregation and 2-year changes in adult sense of control. Method. Complete data on 541 older AAH men and women were used to estimate the association between childhood school segregation and changes in the sense of control. Exposure to segregation was self-reported in 2004, and the sense of control was measured in 2008 and 2010 using Blom rank transformations of Mirowsky and Ross’ 8-item scale. Declining subjective income and experiencing major life stressors between 2008 and 2010, as well as traditional covariates (demographic factors, socioeconomic status, self-rated health, racial attitudes and beliefs, and religiosity) were included for statistical adjustment. Multiple linear regression analysis with propensity score reweighting was used. Results. Receiving the majority of one’s primary and secondary education in segregated schools had a significant net positive association (d = 0.179; p = .029) with 2-year changes in adult sense of control. Conclusion. AAH participants receiving the majority of their primary and secondary educations in segregated schools appeared to have been protected, in part, from age-related declines in the sense of control. PMID:24056692

Use of Segregation Indices, Townsend Index, and Air Toxics Data to Assess Lifetime Cancer Risk Disparities in Metropolitan Charleston, South Carolina, USA

PubMed Central

Rice, LaShanta J.; Jiang, Chengsheng; Wilson, Sacoby M.; Burwell-Naney, Kristen; Samantapudi, Ashok; Zhang, Hongmei

2014-01-01

Background: Studies have demonstrated a relationship between segregation and level of education, occupational opportunities, and risk behaviors, yet a paucity of research has elucidated the association between racial residential segregation, socioeconomic deprivation, and lifetime cancer risk. Objectives: We examined estimated lifetime cancer risk from air toxics by racial composition, segregation, and deprivation in census tracts in Metropolitan Charleston. Methods: Segregation indices were used to measure the distribution of groups of people from different races within neighborhoods. The Townsend Index was used to measure economic deprivation in the study area. Poisson multivariate regressions were applied to assess the association of lifetime cancer risk with segregation indices and Townsend Index along with several sociodemographic measures. Results: Lifetime cancer risk from all pollution sources was 28 persons/million for half of the census tracts in Metropolitan Charleston. Isolation Index and Townsend Index both showed significant correlation with lifetime cancer risk from different sources. This significance still holds after adjusting for other sociodemographic measures in a Poisson regression, and these two indices have stronger effect on lifetime cancer risk compared to the effects of sociodemographic measures. Conclusions: We found that material deprivation, measured by the Townsend Index and segregation measured by the Isolation index, introduced high impact on lifetime cancer risk by air toxics at the census tract level. PMID:24852759

Segregation 2.0: The New Generation of School Segregation in the 21st Century

ERIC Educational Resources Information Center

Thompson Dorsey, Dana N.

2013-01-01

Students are more racially segregated in schools today than they were in the late 1960s and prior to the enforcement of court-ordered desegregation in school districts across the country. This special issue addresses the overarching theme of policies, practices, or roles and responsibilities of various stakeholders that may directly or indirectly…

Settle for Segregation or Strive for Diversity? A Defining Moment for Maryland's Public Schools

ERIC Educational Resources Information Center

Ayscue, Jennifer B.

2013-01-01

Maryland, as one of 17 states that had de jure segregation, has an intense history of school segregation. Following the 1954 Brown decision, school districts across the state employed various methods to desegregate their schools, including mandatory busing in Prince George's County, magnet schools in Montgomery County, and a freedom of choice plan…

Southern Slippage: Growing School Segregation in the Most Desegregated Region of the Country

ERIC Educational Resources Information Center

Siegel-Hawley, Genevieve; Frankenberg, Erica

2012-01-01

The South remains the most desegregated region in the country for black students, but along every measure of segregation and at each level of geography, gains made during the desegregation era are slipping away at a steady pace. This report shows that the segregation of Southern black students has been progressively increasing since judicial…

My Statement on the Moral Aspects of Racial Segregation.

ERIC Educational Resources Information Center

Mays, Benjamin E.

2001-01-01

Presents excerpts from a 1955 essay by Benjamin E. Mays, long-time president of Morehouse College, on the meaning of racial segregation and the damage it inflicted. Describes three reasons for legal segregation, explaining why it is immoral and how it has damaged the souls and minds of millions of African Americans who will never be cured of…

On Separate Paths: The Mexican American and African American Legal Campaigns against School Segregation

ERIC Educational Resources Information Center

Powers, Jeanne M.

2014-01-01

"Brown v. Board of Education" (1954) was a landmark decision that was the result of decades of efforts by grassroots activists and civil rights organizations to end legalized segregation. A less well-known effort challenged the extralegal segregation of Mexican American students in the Southwest. I combine original research and research…

Does Segregation Still Matter? The Impact of Student Composition on Academic Achievement in High School

ERIC Educational Resources Information Center

Rumberger, Russell W.; Palardy, Gregory J.

2005-01-01

The Coleman report, published 12 years after the Brown decision, confirmed that widespread school segregation in the United States created inequality of educational opportunity. This study examines whether racial and socioeconomic segregation, which is on the rise in the United States, is still contributing to the achievement differences among…

Segregation, Desegregation, and Resegregation of the Spanish-Surname Student in the United States.

ERIC Educational Resources Information Center

Valverde, Leonard A.

Since the birth of school integration efforts in America, the mixing of children of different races and ethnicities has gone through segregation, desegregation, and resegregation. Just as the popular misbelief was that Black Americans were segregated in the South where they numerically concentrated and rarely in the North, so too the stereotypic…

Segregated Schools in Segregated Societies: Issues of Safety and Risk

ERIC Educational Resources Information Center

Leonard, Madeleine

2006-01-01

In segregated societies such as Northern Ireland, schools may become sites of risk rather than sites of learning. This is particularly likely to be the case in interface areas, which are demarcated by peace-lines and other symbolic boundaries. Drawing on maps and focus group discussions with teenagers from interface areas in North Belfast, the…

Education Policy and School Segregation of Migrant Students in Catalonia: The Politics of Non-Decision-Making

ERIC Educational Resources Information Center

Bonal, Xavier

2012-01-01

This article shows how the Catalan government has not developed an agenda to tackle school segregation despite the growing number of migrant pupils who arrived over the course of the last decade. Education policy has explicitly disregarded the possibilities of improving the regulatory framework for tackling segregation; it has exercised…

9 CFR 381.72 - Segregation of suspects on ante mortem inspection.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Segregation of suspects on ante mortem inspection. 381.72 Section 381.72 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... Inspection § 381.72 Segregation of suspects on ante mortem inspection. (a) All birds, except ratites, that on...

46 CFR 32.60-15 - Segregation of cargo; Grade E-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Segregation of cargo; Grade E-TB/ALL. 32.60-15 Section 32.60-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT... § 32.60-15 Segregation of cargo; Grade E—TB/ALL. (a) General. The galleys, living quarters, navigation...

46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Segregation of spaces containing the emergency source of electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section...

46 CFR 32.60-15 - Segregation of cargo; Grade E-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Segregation of cargo; Grade E-TB/ALL. 32.60-15 Section 32.60-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT... § 32.60-15 Segregation of cargo; Grade E—TB/ALL. (a) General. The galleys, living quarters, navigation...

Legally White, Socially "Mexican": The Politics of De Jure and De Facto School Segregation in the American Southwest

ERIC Educational Resources Information Center

Donato, Ruben; Hanson, Jarrod S.

2012-01-01

The history of Mexican American school segregation is complex, often misunderstood, and currently unresolved. The literature suggests that Mexican Americans experienced de facto segregation because it was local custom and never sanctioned at the state level in the American Southwest. However, the same literature suggests that Mexican Americans…

46 CFR 190.05-15 - Segregation of spaces containing the emergency source of electric power.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Segregation of spaces containing the emergency source of electric power. 190.05-15 Section 190.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... Segregation of spaces containing the emergency source of electric power. (a) When a compartment containing the...

Causes of Educational Segregation in Sweden--School Choice or Residential Segregation

ERIC Educational Resources Information Center

Yang Hansen, Kajsa; Gustafsson, Jan-Eric

2016-01-01

The aims of the study were to examine changes in school segregation across different types of municipalities between 1998 and 2011 in Sweden, and to explore the extent to which these changes are the consequences of school choice. Multilevel models were applied to register data using a counterfactual approach. The results showed that school…

46 CFR 92.05-15 - Segregation of spaces containing the emergency source of electric power.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Segregation of spaces containing the emergency source of electric power. 92.05-15 Section 92.05-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Segregation of spaces containing the emergency source of electric power. (a) The provisions of this section...

School Segregation and Racial Academic Achievement Gaps. CEPA Working Paper No. 15-12

ERIC Educational Resources Information Center

Reardon, Sean F.

2015-01-01

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

77 FR 24219 - Notice of Realty Action; Notice of Segregation and Proposed Sale of Public Lands, Sweetwater...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-23

... DEPARTMENT OF THE INTERIOR Bureau of Land Management [LLWY9210000. L143000000.EU0000, WYW167526] Notice of Realty Action; Notice of Segregation and Proposed Sale of Public Lands, Sweetwater County, WY... the issuance of a patent, publication in the Federal Register of a termination of the segregation, or...

9 CFR 381.72 - Segregation of suspects on ante mortem inspection.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Segregation of suspects on ante mortem inspection. 381.72 Section 381.72 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... Inspection § 381.72 Segregation of suspects on ante mortem inspection. (a) All birds, except ratites, that on...

The Gerrymandering of School Attendance Zones and the Segregation of Public Schools: A Geospatial Analysis

ERIC Educational Resources Information Center

Richards, Meredith P.

2014-01-01

In this study, I employ geospatial techniques to assess the impact of school attendance zone "gerrymandering" on the racial/ethnic segregation of schools, using a large national sample of 15,290 attendance zones in 663 districts. I estimate the effect of gerrymandering on school diversity and school district segregation by comparing the…

A Quantitative Analysis of the Increase in Public School Segregation in Delaware: 1989-2006

ERIC Educational Resources Information Center

Glenn, William J.

2011-01-01

This study analyzes the increase in school segregation in Delaware from a quantitative perspective. The article tests the hypothesis that the declaration of unitary status that released the Wilmington area school districts from their desegregation order caused the increase in segregation. The research reveals that the declaration of unitary status…

43 CFR 3135.1-8 - Termination of administration for conveyed lands and segregation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Termination of administration for conveyed lands and segregation. 3135.1-8 Section 3135.1-8 Public Lands: Interior Regulations Relating to Public... Suspensions § 3135.1-8 Termination of administration for conveyed lands and segregation. (a) If all of the...

78 FR 58555 - Notice of Segregation of Public Lands for the Proposed Stateline Solar Farm, CA

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-24

... Solar Energy right-of-way (ROW) application and provide for the orderly administration of public lands... solar energy project on a portion of its ROW-application area. The BLM is segregating the following...; CACA-048669] Notice of Segregation of Public Lands for the Proposed Stateline Solar Farm, CA AGENCY...

11 CFR 106.6 - Allocation of expenses between federal and non-federal activities by separate segregated funds...

Code of Federal Regulations, 2010 CFR

2010-01-01

... District of Columbia ordered that paragraphs (c) and (f) of § 106.6 are vacated. See Final Order, EMILY's... instructions direct the separate segregated fund's or nonconnected committee's employee or volunteer to refer... instructions direct the separate segregated fund's or nonconnected committee's employee or volunteer to refer...

11 CFR 106.6 - Allocation of expenses between federal and non-federal activities by separate segregated funds...

Code of Federal Regulations, 2011 CFR

2011-01-01

... Final Order, EMILY's List v. FEC, No. 05-0049 (D.D.C. Nov. 30, 2009). [55 FR 26071, June 26, 1990, as... instructions direct the separate segregated fund's or nonconnected committee's employee or volunteer to refer... instructions direct the separate segregated fund's or nonconnected committee's employee or volunteer to refer...

43 CFR 2091.5-4 - Segregative effect and opening: Water power withdrawals.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Segregative effect and opening: Water power withdrawals. 2091.5-4 Section 2091.5-4 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) SPECIAL LAWS AND RULES Segregation and Opening of...

Challenging Segregational Practices in a Spanish Secondary School: Results from an Ethnographic Research

ERIC Educational Resources Information Center

Sanchez-Valero, Joan-Anton; Padilla-Petry, Paulo

2016-01-01

This article presents partial results of a multi-sited ethnographic study about the role of multiple literacies in young people's learning in and outside school. In one of the five participant secondary schools, fourth grade students were segregated in groups according to their special needs. We start with a critical review on segregated and…

Socioeconomic School Segregation in a Market-Oriented Educational System. The Case of Chile

ERIC Educational Resources Information Center

Valenzuela, Juan Pablo; Bellei, Cristian; de los Ríos, Danae

2014-01-01

This paper presents an empirical analysis of the socioeconomic status (SES) school segregation in Chile, whose educational system is regarded as an extreme case of a market-oriented education. The study estimated the magnitude and evolution of the SES segregation of schools at both national and local levels, and it studied the relationship between…

Residential segregation and mental health among Latinos in a nationally representative survey

PubMed Central

Nobles, Carrie J; Valentine, Sarah E; Zepeda, E David; Wang, Ye; Ahles, Emily M; Shtasel, Derri L; Marques, Luana

2017-01-01

Background Among Latinos, living in a locality with greater Latino ethnic density may be protective for mental health, although findings vary by Latino subgroup, gender and birthplace. Although little studied, Latino residential segregation may capture different pathways linking risk and protective environmental factors to mental health than local ethnic density. Methods This study evaluated the association between residential segregation and mental distress as measured by the Kessler-10 (K10) among Latino participants in the National Latino and Asian American Study (NLAAS). Census data from 2000 was used to calculate metropolitan statistical area (MSA) residential segregation using the dissimilarity and isolation indices, as well as census tract ethnicity density and poverty. Latino subgroup (Puerto Rican, Mexican American, Cuban American and other Latino subgroup), gender and generation status were evaluated as moderators. Results Among 2554 Latino participants in NLAAS, residential segregation as measured by the isolation index was associated with less mental distress (β −0.14, 95% CI −0.26 to −0.03 log(K10)) among Latinos overall after adjustment for ethnic density, poverty and individual covariates. Residential segregation as measured by the dissimilarity index was significantly associated with less mental distress among men (β −0.56, 95% CI −1.04 to −0.08) but not among women (β −0.20, 95% CI −0.45 to 0.04, p-interaction=0.019). No modification was observed by Latino subgroup or generation. Conclusions Among Latinos, increasing residential segregation was associated with less mental distress, and this association was moderated by gender. Findings suggest that MSA-level segregation measures may capture protective effects associated with living in Latino communities for mental health. PMID:27885049

Particle-size segregation and diffusive remixing in shallow granular avalanches

NASA Astrophysics Data System (ADS)

Gray, J. M. N. T.; Chugunov, V. A.

2006-12-01

Segregation and mixing of dissimilar grains is a problem in many industrial and pharmaceutical processes, as well as in hazardous geophysical flows, where the size-distribution can have a major impact on the local rheology and the overall run-out. In this paper, a simple binary mixture theory is used to formulate a model for particle-size segregation and diffusive remixing of large and small particles in shallow gravity-driven free-surface flows. This builds on a recent theory for the process of kinetic sieving, which is the dominant mechanism for segregation in granular avalanches provided the density-ratio and the size-ratio of the particles are not too large. The resulting nonlinear parabolic segregation remixing equation reduces to a quasi-linear hyperbolic equation in the no-remixing limit. It assumes that the bulk velocity is incompressible and that the bulk pressure is lithostatic, making it compatible with most theories used to compute the motion of shallow granular free-surface flows. In steady-state, the segregation remixing equation reduces to a logistic type equation and the ‘S’-shaped solutions are in very good agreement with existing particle dynamics simulations for both size and density segregation. Laterally uniform time-dependent solutions are constructed by mapping the segregation remixing equation to Burgers equation and using the Cole Hopf transformation to linearize the problem. It is then shown how solutions for arbitrary initial conditions can be constructed using standard methods. Three examples are investigated in which the initial concentration is (i) homogeneous, (ii) reverse graded with the coarse grains above the fines, and, (iii) normally graded with the fines above the coarse grains. Time-dependent two-dimensional solutions are also constructed for plug-flow in a semi-infinite chute.

Reverberation impairs brainstem temporal representations of voiced vowel sounds: challenging “periodicity-tagged” segregation of competing speech in rooms

PubMed Central

Sayles, Mark; Stasiak, Arkadiusz; Winter, Ian M.

2015-01-01

The auditory system typically processes information from concurrently active sound sources (e.g., two voices speaking at once), in the presence of multiple delayed, attenuated and distorted sound-wave reflections (reverberation). Brainstem circuits help segregate these complex acoustic mixtures into “auditory objects.” Psychophysical studies demonstrate a strong interaction between reverberation and fundamental-frequency (F0) modulation, leading to impaired segregation of competing vowels when segregation is on the basis of F0 differences. Neurophysiological studies of complex-sound segregation have concentrated on sounds with steady F0s, in anechoic environments. However, F0 modulation and reverberation are quasi-ubiquitous. We examine the ability of 129 single units in the ventral cochlear nucleus (VCN) of the anesthetized guinea pig to segregate the concurrent synthetic vowel sounds /a/ and /i/, based on temporal discharge patterns under closed-field conditions. We address the effects of added real-room reverberation, F0 modulation, and the interaction of these two factors, on brainstem neural segregation of voiced speech sounds. A firing-rate representation of single-vowels' spectral envelopes is robust to the combination of F0 modulation and reverberation: local firing-rate maxima and minima across the tonotopic array code vowel-formant structure. However, single-vowel F0-related periodicity information in shuffled inter-spike interval distributions is significantly degraded in the combined presence of reverberation and F0 modulation. Hence, segregation of double-vowels' spectral energy into two streams (corresponding to the two vowels), on the basis of temporal discharge patterns, is impaired by reverberation; specifically when F0 is modulated. All unit types (primary-like, chopper, onset) are similarly affected. These results offer neurophysiological insights to perceptual organization of complex acoustic scenes under realistically challenging listening conditions. PMID:25628545

Neural Representation of Concurrent Harmonic Sounds in Monkey Primary Auditory Cortex: Implications for Models of Auditory Scene Analysis

PubMed Central

Steinschneider, Mitchell; Micheyl, Christophe

2014-01-01

The ability to attend to a particular sound in a noisy environment is an essential aspect of hearing. To accomplish this feat, the auditory system must segregate sounds that overlap in frequency and time. Many natural sounds, such as human voices, consist of harmonics of a common fundamental frequency (F0). Such harmonic complex tones (HCTs) evoke a pitch corresponding to their F0. A difference in pitch between simultaneous HCTs provides a powerful cue for their segregation. The neural mechanisms underlying concurrent sound segregation based on pitch differences are poorly understood. Here, we examined neural responses in monkey primary auditory cortex (A1) to two concurrent HCTs that differed in F0 such that they are heard as two separate “auditory objects” with distinct pitches. We found that A1 can resolve, via a rate-place code, the lower harmonics of both HCTs, a prerequisite for deriving their pitches and for their perceptual segregation. Onset asynchrony between the HCTs enhanced the neural representation of their harmonics, paralleling their improved perceptual segregation in humans. Pitches of the concurrent HCTs could also be temporally represented by neuronal phase-locking at their respective F0s. Furthermore, a model of A1 responses using harmonic templates could qualitatively reproduce psychophysical data on concurrent sound segregation in humans. Finally, we identified a possible intracortical homolog of the “object-related negativity” recorded noninvasively in humans, which correlates with the perceptual segregation of concurrent sounds. Findings indicate that A1 contains sufficient spectral and temporal information for segregating concurrent sounds based on differences in pitch. PMID:25209282

Disparities in Surgical Treatment of Early-Stage Breast Cancer Among Female Residents of Texas: The Role of Racial Residential Segregation.

PubMed

Ojinnaka, Chinedum O; Luo, Wen; Ory, Marcia G; McMaughan, Darcy; Bolin, Jane N

2017-04-01

Early-stage breast cancer can be surgically treated by using mastectomy or breast-conserving surgery and adjuvant radiotherapy, also known as breast-conserving therapy (BCT). Little is known about the association between racial residential segregation, year of diagnosis, and surgical treatment of early-stage breast cancer, and whether racial residential segregation influences the association between other demographic characteristics and disparities in surgical treatment. This was a retrospective study using data from the Texas Cancer Registry composed of individuals diagnosed with breast cancer between 1995 and 2012. The dependent variable was treatment using mastectomy or BCT (M/BCT) and the independent variables of interest (IVs) were racial residential segregation and year of diagnosis. The covariates were race, residence, ethnicity, tumor grade, census tract (CT) poverty level, age at diagnosis, stage at diagnosis, and year of diagnosis. Bivariate and multivariable multilevel logistic regression models were estimated. The final sample size was 69,824 individuals nested within 4335 CTs. Adjusting for the IVs and all covariates, there were significantly decreased odds of treatment using M/BCT, as racial residential segregation increased from 0 to 1 (odds ratio [OR] 0.47; 95% confidence interval [CI], 0.41-0.54). There was also an increased likelihood of treatment using M/BCT with increasing year of diagnosis (OR 1.14; 95% CI, 1.13-1.16). A positive interaction effect between racial residential segregation and race was observed (OR 0.56; 95% CI, 0.36-0.88). Residents of areas with high indices of racial residential segregation were less likely to be treated with M/BCT. Racial disparities in treatment using M/BCT increased with increasing racial residential segregation. Copyright © 2016 Elsevier Inc. All rights reserved.

The Racial/Ethnic Distribution of Heat Risk–Related Land Cover in Relation to Residential Segregation

PubMed Central

Morello-Frosch, Rachel; Cushing, Lara

2013-01-01

Objective: We examined the distribution of heat risk–related land cover (HRRLC) characteristics across racial/ethnic groups and degrees of residential segregation. Methods: Block group–level tree canopy and impervious surface estimates were derived from the 2001 National Land Cover Dataset for densely populated urban areas of the United States and Puerto Rico, and linked to demographic characteristics from the 2000 Census. Racial/ethnic groups in a given block group were considered to live in HRRLC if at least half their population experienced the absence of tree canopy and at least half of the ground was covered by impervious surface (roofs, driveways, sidewalks, roads). Residential segregation was characterized for metropolitan areas in the United States and Puerto Rico using the multigroup dissimilarity index. Results: After adjustment for ecoregion and precipitation, holding segregation level constant, non-Hispanic blacks were 52% more likely (95% CI: 37%, 69%), non-Hispanic Asians 32% more likely (95% CI: 18%, 47%), and Hispanics 21% more likely (95% CI: 8%, 35%) to live in HRRLC conditions compared with non-Hispanic whites. Within each racial/ethnic group, HRRLC conditions increased with increasing degrees of metropolitan area-level segregation. Further adjustment for home ownership and poverty did not substantially alter these results, but adjustment for population density and metropolitan area population attenuated the segregation effects, suggesting a mediating or confounding role. Conclusions: Land cover was associated with segregation within each racial/ethnic group, which may be explained partly by the concentration of racial/ethnic minorities into densely populated neighborhoods within larger, more segregated cities. In anticipation of greater frequency and duration of extreme heat events, climate change adaptation strategies, such as planting trees in urban areas, should explicitly incorporate an environmental justice framework that addresses racial/ethnic disparities in HRRLC. PMID:23694846

Grain-size segregation and levee formation in geophysical mass flows

USGS Publications Warehouse

Johnson, C.G.; Kokelaar, B.P.; Iverson, Richard M.; Logan, M.; LaHusen, R.G.; Gray, J.M.N.T.

2012-01-01

Data from large-scale debris-flow experiments are combined with modeling of particle-size segregation to explain the formation of lateral levees enriched in coarse grains. The experimental flows consisted of 10 m3 of water-saturated sand and gravel, which traveled ∼80 m down a steeply inclined flume before forming an elongated leveed deposit 10 m long on a nearly horizontal runout surface. We measured the surface velocity field and observed the sequence of deposition by seeding tracers onto the flow surface and tracking them in video footage. Levees formed by progressive downslope accretion approximately 3.5 m behind the flow front, which advanced steadily at ∼2 m s−1during most of the runout. Segregation was measured by placing ∼600 coarse tracer pebbles on the bed, which, when entrained into the flow, segregated upwards at ∼6–7.5 cm s−1. When excavated from the deposit these were distributed in a horseshoe-shaped pattern that became increasingly elevated closer to the deposit termination. Although there was clear evidence for inverse grading during the flow, transect sampling revealed that the resulting leveed deposit was strongly graded laterally, with only weak vertical grading. We construct an empirical, three-dimensional velocity field resembling the experimental observations, and use this with a particle-size segregation model to predict the segregation and transport of material through the flow. We infer that coarse material segregates to the flow surface and is transported to the flow front by shear. Within the flow head, coarse material is overridden, then recirculates in spiral trajectories due to size-segregation, before being advected to the flow edges and deposited to form coarse-particle-enriched levees.

Grain-size segregation and levee formation in geophysical mass flows

USGS Publications Warehouse

Johnson, C.G.; Kokelaar, B.P.; Iverson, R.M.; Logan, M.; LaHusen, R.G.; Gray, J.M.N.T.

2012-01-01

Data from large-scale debris-flow experiments are combined with modeling of particle-size segregation to explain the formation of lateral levees enriched in coarse grains. The experimental flows consisted of 10 m3 of water-saturated sand and gravel, which traveled ~80 m down a steeply inclined flume before forming an elongated leveed deposit 10 m long on a nearly horizontal runout surface. We measured the surface velocity field and observed the sequence of deposition by seeding tracers onto the flow surface and tracking them in video footage. Levees formed by progressive downslope accretion approximately 3.5 m behind the flow front, which advanced steadily at ~2 m s-1 during most of the runout. Segregation was measured by placing ~600 coarse tracer pebbles on the bed, which, when entrained into the flow, segregated upwards at ~6–7.5 cm s-1. When excavated from the deposit these were distributed in a horseshoe-shaped pattern that became increasingly elevated closer to the deposit termination. Although there was clear evidence for inverse grading during the flow, transect sampling revealed that the resulting leveed deposit was strongly graded laterally, with only weak vertical grading. We construct an empirical, three-dimensional velocity field resembling the experimental observations, and use this with a particle-size segregation model to predict the segregation and transport of material through the flow. We infer that coarse material segregates to the flow surface and is transported to the flow front by shear. Within the flow head, coarse material is overridden, then recirculates in spiral trajectories due to size-segregation, before being advected to the flow edges and deposited to form coarse-particle-enriched levees.

Residential segregation and mental health among Latinos in a nationally representative survey.

PubMed

Nobles, Carrie J; Valentine, Sarah E; Zepeda, E David; Wang, Ye; Ahles, Emily M; Shtasel, Derri L; Marques, Luana

2017-04-01

Among Latinos, living in a locality with greater Latino ethnic density may be protective for mental health, although findings vary by Latino subgroup, gender and birthplace. Although little studied, Latino residential segregation may capture different pathways linking risk and protective environmental factors to mental health than local ethnic density. This study evaluated the association between residential segregation and mental distress as measured by the Kessler-10 (K10) among Latino participants in the National Latino and Asian American Study (NLAAS). Census data from 2000 was used to calculate metropolitan statistical area (MSA) residential segregation using the dissimilarity and isolation indices, as well as census tract ethnicity density and poverty. Latino subgroup (Puerto Rican, Mexican American, Cuban American and other Latino subgroup), gender and generation status were evaluated as moderators. Among 2554 Latino participants in NLAAS, residential segregation as measured by the isolation index was associated with less mental distress (β -0.14, 95% CI -0.26 to -0.03 log(K10)) among Latinos overall after adjustment for ethnic density, poverty and individual covariates. Residential segregation as measured by the dissimilarity index was significantly associated with less mental distress among men (β -0.56, 95% CI -1.04 to -0.08) but not among women (β -0.20, 95% CI -0.45 to 0.04, p-interaction=0.019). No modification was observed by Latino subgroup or generation. Among Latinos, increasing residential segregation was associated with less mental distress, and this association was moderated by gender. Findings suggest that MSA-level segregation measures may capture protective effects associated with living in Latino communities for mental health. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Solute segregation and deviation from bulk thermodynamics at nanoscale crystalline defects.

PubMed

Titus, Michael S; Rhein, Robert K; Wells, Peter B; Dodge, Philip C; Viswanathan, Gopal Babu; Mills, Michael J; Van der Ven, Anton; Pollock, Tresa M

2016-12-01

It has long been known that solute segregation at crystalline defects can have profound effects on material properties. Nevertheless, quantifying the extent of solute segregation at nanoscale defects has proven challenging due to experimental limitations. A combined experimental and first-principles approach has been used to study solute segregation at extended intermetallic phases ranging from 4 to 35 atomic layers in thickness. Chemical mapping by both atom probe tomography and high-resolution scanning transmission electron microscopy demonstrates a markedly different composition for the 4-atomic-layer-thick phase, where segregation has occurred, compared to the approximately 35-atomic-layer-thick bulk phase of the same crystal structure. First-principles predictions of bulk free energies in conjunction with direct atomistic simulations of the intermetallic structure and chemistry demonstrate the breakdown of bulk thermodynamics at nanometer dimensions and highlight the importance of symmetry breaking due to the proximity of interfaces in determining equilibrium properties.

Solute segregation and deviation from bulk thermodynamics at nanoscale crystalline defects

PubMed Central

Titus, Michael S.; Rhein, Robert K.; Wells, Peter B.; Dodge, Philip C.; Viswanathan, Gopal Babu; Mills, Michael J.; Van der Ven, Anton; Pollock, Tresa M.

2016-01-01

It has long been known that solute segregation at crystalline defects can have profound effects on material properties. Nevertheless, quantifying the extent of solute segregation at nanoscale defects has proven challenging due to experimental limitations. A combined experimental and first-principles approach has been used to study solute segregation at extended intermetallic phases ranging from 4 to 35 atomic layers in thickness. Chemical mapping by both atom probe tomography and high-resolution scanning transmission electron microscopy demonstrates a markedly different composition for the 4–atomic-layer–thick phase, where segregation has occurred, compared to the approximately 35–atomic-layer–thick bulk phase of the same crystal structure. First-principles predictions of bulk free energies in conjunction with direct atomistic simulations of the intermetallic structure and chemistry demonstrate the breakdown of bulk thermodynamics at nanometer dimensions and highlight the importance of symmetry breaking due to the proximity of interfaces in determining equilibrium properties. PMID:28028543

Self-organized carbon-rich stripe formation from competitive carbon and aluminium segregation at Fe0.85Al0.15(1 1 0) surfaces

NASA Astrophysics Data System (ADS)

Dai, Zongbei; Borghetti, Patrizia; Mouchaal, Younes; Chenot, Stéphane; David, Pascal; Jupille, Jacques; Cabailh, Gregory; Lazzari, Rémi

2018-06-01

By combining Scanning Tunnelling Microscopy, Low Energy Electron Diffraction and X-ray Photoelectron Spectroscopy, it was found that the surface of A2 random alloy Fe0.85Al0.15(1 1 0) is significantly influenced by the segregation of aluminium but also of carbon bulk impurities. Below ∼ 900 K, carbon segregates in the form of self-organized protruding stripes separated by ∼ 5 nm that run along the [ 0 0 1 ] B bulk direction and cover up to 34% of the surface. Their C 1s spectroscopic signature that is dominated by graphitic carbon peaks around 900 K. Above this temperature, the surface carbon concentration decays by redissolution in the bulk, whereas an intense aluminium segregation is observed giving rise to a hexagonal superstructure. The present findings is interpreted by a competitive segregation between the two elements.

Concentration transient analysis of antimony surface segregation during Si(100) molecular beam epitaxy

NASA Technical Reports Server (NTRS)

Markert, L. C.; Greene, J. E.; Ni, W.-X.; Hansson, G. V.; Sundgren, J.-E.

1991-01-01

Antimony surface segregation during Si(100) molecular beam epitaxy (MBE) was investigated at temperatures T(sub s) = 515 - 800 C using concentration transient analysis (CTA). The dopant surface coverage Theta, bulk fraction gamma, and incorporation probability sigma during MBE were determined from secondary-ion mass spectrometry depth profiles of modulation-doped films. Programmed T(sub s) changes during growth were used to trap the surface-segregated dopant overlayer, producing concentration spikes whose integrated area corresponds to Theta. Thermal antimony doping by coevaporation was found to result in segregation strongly dependent on T(sub s) with Theta(sub Sb) values up to 0.9 monolayers (ML): in films doped with Sb(+) ions accelerated by 100 V, Theta(sub Sb) was less than or equal to 4 x 10(exp -3) ML. Surface segregation of coevaporated antimony was kinematically limited for the film growth conditions in these experiments.

Evolution of wetting layer in InAs/GaAs quantum dot system

PubMed Central

Ye, XL; Wang, ZG

2006-01-01

For InAs/GaAs quantum dot system, the evolution of the wetting layer (WL) with the InAs deposition thickness has been studied by reflectance difference spectroscopy (RDS). Two transitions related to the heavy- and light-hole in the WL have been distinguished in RD spectra. Taking into account the strain and segregation effects, a model has been presented to deduce the InAs amount in the WL and the segregation coefficient of the indium atoms from the transition energies of heavy- and light-holes. The variation of the InAs amount in the WL and the segregation coefficient are found to rely closely on the growth modes. In addition, the huge dots also exhibits a strong effect on the evolution of the WL. The observed linear dependence of In segregation coefficient upon the InAs amount in the WL demonstrates that the segregation is enhanced by the strain in the WL.

Structure and information in spatial segregation

PubMed Central

2017-01-01

Ethnoracial residential segregation is a complex, multiscalar phenomenon with immense moral and economic costs. Modeling the structure and dynamics of segregation is a pressing problem for sociology and urban planning, but existing methods have limitations. In this paper, we develop a suite of methods, grounded in information theory, for studying the spatial structure of segregation. We first advance existing profile and decomposition methods by posing two related regionalization methods, which allow for profile curves with nonconstant spatial scale and decomposition analysis with nonarbitrary areal units. We then formulate a measure of local spatial scale, which may be used for both detailed, within-city analysis and intercity comparisons. These methods highlight detailed insights in the structure and dynamics of urban segregation that would be otherwise easy to miss or difficult to quantify. They are computationally efficient, applicable to a broad range of study questions, and freely available in open source software. PMID:29078323

A Commentary on Age Segregation for Older Prisoners

PubMed Central

Kerbs, John J.; Jolley, Jennifer M.

2014-01-01

The growing number of older prisoners in state and federal prisons has fostered an important discussion in literature regarding the potential benefits of age-segregated living arrangements for older inmates. This article begins with a brief review of the reasons for America's aging prison population. Thereafter, it uses a multidisciplinary literature review to clarify a 4-point rationale for age-segregated prisons: (a) cost savings via centralized health care for older prisoners; (b) the reduction of civil liabilities for correctional systems that centralize disability services as per requirements of the Americans with Disabilities Act of 1990; (c) the advancement of prisoner safety for older inmates; and (d) the promotion of rehabilitation by advancing treatment opportunities with a group that is most likely to desist from future criminal activity (in part) due to age-related desistance from crime. Conclusions focus on age segregation within the historical context of segregation in prison based on sociodemographic characteristics. PMID:28316366

Structure and information in spatial segregation.

PubMed

Chodrow, Philip S

2017-10-31

Ethnoracial residential segregation is a complex, multiscalar phenomenon with immense moral and economic costs. Modeling the structure and dynamics of segregation is a pressing problem for sociology and urban planning, but existing methods have limitations. In this paper, we develop a suite of methods, grounded in information theory, for studying the spatial structure of segregation. We first advance existing profile and decomposition methods by posing two related regionalization methods, which allow for profile curves with nonconstant spatial scale and decomposition analysis with nonarbitrary areal units. We then formulate a measure of local spatial scale, which may be used for both detailed, within-city analysis and intercity comparisons. These methods highlight detailed insights in the structure and dynamics of urban segregation that would be otherwise easy to miss or difficult to quantify. They are computationally efficient, applicable to a broad range of study questions, and freely available in open source software. Published under the PNAS license.

High-Efficiency Inhibition of Gravity Segregation in Al-Bi Immiscible Alloys by Adding Lanthanum

NASA Astrophysics Data System (ADS)

Jia, Peng; Zhang, Jinyang; Geng, Haoran; Teng, Xinying; Zhao, Degang; Yang, Zhongxi; Wang, Yi; Hu, Song; Xiang, Jun; Hu, Xun

2018-05-01

The inhibition of gravity segregation has been a long-standing challenge in fabrication and applications of homogeneous immiscible alloys. Therefore, the effect of rare-earth La on the gravity segregation of Al-Bi immiscible alloys was investigated to understand the homogenization mechanism. The results showed that the addition of La can completely suppress the gravity segregation. This is attributed to the nucleation of Bi-rich liquid phase on the in-situ produced LaBi2 phase and the change of the shape of LaBi2@Bi droplets. In addition, a novel strategy is developed to prepare the homogeneous immiscible alloys through the addition of rare-earth elements. This strategy not only is applicable to other immiscible alloys, but also is conducive to finding more elements to suppress the gravity segregation. This study provided a useful reference for the fabrication of the homogeneous immiscible alloys.

Influence of Secondary Cooling Mode on Solidification Structure and Macro-segregation Behavior for High-carbon Continuous Casting Bloom

NASA Astrophysics Data System (ADS)

Dou, Kun; Yang, Zhenguo; Liu, Qing; Huang, Yunhua; Dong, Hongbiao

2017-07-01

A cellular automaton-finite element coupling model for high-carbon continuously cast bloom of GCr15 steel is established to simulate the solidification structure and to investigate the influence of different secondary cooling modes on characteristic parameters such as equiaxed crystal ratio, grain size and secondary dendrite arm spacing, in which the effect of phase transformation and electromagnetic stirring is taken into consideration. On this basis, evolution of carbon macro-segregation for GCr15 steel bloom is researched correspondingly via industrial tests. Based on above analysis, the relationship among secondary cooling modes, characteristic parameters for solidification structure as well as carbon macro-segregation is illustrated to obtain optimum secondary cooling strategy and alleviate carbon macro-segregation degree for GCr15 steel bloom in continuous casting process. The evaluating method for element macro-segregation is applicable in various steel types.

CENP-A regulates chromosome segregation during the first meiosis of mouse oocytes.

PubMed

Li, Li; Qi, Shu-Tao; Sun, Qing-Yuan; Chen, Shi-Ling

2017-06-01

Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chromosomes during cell division and result in aneuploidy, thus kinetochores are critical for faithful segregation of chromosomes. Centromere protein A (CENP-A) is an important component of the inner kinetochore plate. Multiple studies in mitosis have found that deficiencies in CENP-A could result in structural and functional changes of kinetochores, leading to abnormal chromosome segregation, aneuploidy and apoptosis in cells. Here we report the expression and function of CENP-A during mouse oocyte meiosis. Our study found that microinjection of CENP-A blocking antibody resulted in errors of homologous chromosome segregation and caused aneuploidy in eggs. Thus, our findings provide evidence that CENP-A is critical for the faithful chromosome segregation during mammalian oocyte meiosis.

Direct Observation of the Surface Segregation of Cu in Pd by Time-Resolved Positron-Annihilation-Induced Auger Electron Spectroscopy

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

Mayer, J.; Hugenschmidt, C.; Schreckenbach, K.

2010-11-12

Density functional theory calculations predict the surface segregation of Cu in the second atomic layer of Pd which has not been unambiguously confirmed by experiment so far. We report measurements on Pd surfaces covered with three and six monolayers of Cu using element selective positron-annihilation-induced Auger electron spectroscopy (PAES) which is sensitive to the topmost atomic layer. Moreover, time-resolved PAES, which was applied for the first time, enables the investigation of the dynamics of surface atoms and hence the observation of the segregation process. The time constant for segregation was experimentally determined to {tau}=1.38(0.21) h, and the final segregated configurationmore » was found to be consistent with calculations. Time-dependent PAES is demonstrated to be a novel element selective technique applicable for the investigation of, e.g., heterogeneous catalysis, corrosion, or surface alloying.« less

Direct Observation of the Surface Segregation of Cu in Pd by Time-Resolved Positron-Annihilation-Induced Auger Electron Spectroscopy

NASA Astrophysics Data System (ADS)

Mayer, J.; Hugenschmidt, C.; Schreckenbach, K.

2010-11-01

Density functional theory calculations predict the surface segregation of Cu in the second atomic layer of Pd which has not been unambiguously confirmed by experiment so far. We report measurements on Pd surfaces covered with three and six monolayers of Cu using element selective positron-annihilation-induced Auger electron spectroscopy (PAES) which is sensitive to the topmost atomic layer. Moreover, time-resolved PAES, which was applied for the first time, enables the investigation of the dynamics of surface atoms and hence the observation of the segregation process. The time constant for segregation was experimentally determined to τ=1.38(0.21)h, and the final segregated configuration was found to be consistent with calculations. Time-dependent PAES is demonstrated to be a novel element selective technique applicable for the investigation of, e.g., heterogeneous catalysis, corrosion, or surface alloying.

Phosphorus Segregation in Meta-Rapidly Solidified Carbon Steels

NASA Astrophysics Data System (ADS)

Li, Na; Qiao, Jun; Zhang, Junwei; Sha, Minghong; Li, Shengli

2017-09-01

Twin-roll strip casters for near-net-shape manufacture of steels have received increased attention in the steel industry. Although negative segregation of phosphorus occurred in twin-roll strip casting (TRSC) steels in our prior work, its mechanism is still unclear. In this work, V-shaped molds were designed and used to simulate a meta-rapid solidification process without roll separating force during twin roll casting of carbon steels. Experimental results show that no obvious phosphorus segregation exist in the V-shaped mold casting (VMC) steels. By comparing TRSC and the VMC, it is proposed that the negative phosphorus segregation during TRSC results from phosphorus redistribution driven by recirculating and vortex flow in the molten pool. Meanwhile, solute atoms near the advancing interface are overtaken and incorporated into the solid because of the high solidification speed. The high rolling force could promote the negative segregation of alloying elements in TRSC.

Shift Happens. How Halide Ion Defects Influence Photoinduced Segregation in Mixed Halide Perovskites

DOE PAGES

Yoon, Seog Joon; Kuno, Masaru; Kamat, Prashant V.

2017-06-01

Minimizing photoinduced segregation in mixed halide lead perovskites is important for achieving stable photovoltaic performance. The shift in the absorption and the rate of formation of iodide- and bromide-rich regions following visible excitation of mixed halide lead perovskites is found to strongly depend on the halide ion concentration. Slower formation and recovery rates observed in halide-deficient films indicate the involvement of defect sites in influencing halide phase segregation. At higher halide concentrations (in stoichiometric excess), segregation effects become less prominent, as evidenced by faster recovery kinetics. These results suggest that light-induced compositional segregation can be minimized in mixed halide perovskitemore » films by using excess halide ions. In conclusion, the findings from this study further reflect the importance of halide ion post-treatment of perovskite films to improve their solar cell performance.« less

The effect of primary recoil spectrum on radiation induced segregation in nickel-silicon alloys

NASA Astrophysics Data System (ADS)

Averback, R. S.; Rehn, L. E.; Wagner, W.; Ehrhart, P.

1983-08-01

Segregation of silicon to the surface of Ni-12.7 at% Si alloys during 2.0-MeV He and 3.25-MeV Kr irradiations was measured using Rutherford backscattering spectrometry. For equal calculated defect production rates the Kr irradiation was < 3 % as efficient as the He irradiation for promoting segregation in the temperature range, 450 °C-580 °C. It was further observed that Kr preirradiation of specimens dramatically reduced segregation during subsequent He irradiation. A model for cascade annealing in Ni-Si alloys is presented which qualitatively explains the segregation results. The model assumes that small interstitial-atom-clusters form in individual cascades and that these clusters become trapped at silicon solute atoms. The vacancy thereby becomes the more mobile defect. The model should also have relevance for the observation that void swelling in nickel is suppressed by the addition of silicon solute.

Segregation of Sb in Ge epitaxial layers and its usage for the selective doping of Ge-based structures

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

Antonov, A. V.; Drozdov, M. N.; Novikov, A. V., E-mail: anov@ipmras.ru

2015-11-15

The segregation of Sb in Ge epitaxial layers grown by the method of molecular beam epitaxy on Ge (001) substrates is investigated. For a growth temperature range of 180–325°C, the temperature dependence is determined for the segregation ratio of Sb in Ge, which shows a sharp increase (by more than three orders of magnitude) with increasing temperature. The strong dependence of the segregation properties of Sb on the growth temperature makes it possible to adapt a method based on the controlled use of segregation developed previously for the doping of Si structures for the selective doping of Ge structures withmore » a donor impurity. Using this method selectively doped Ge:Sb structures, in which the bulk impurity concentration varies by an order of magnitude at distances of 3–5 nm, are obtained.« less

Socio-Economic Segregation of Disadvantaged Children between Schools in Pakistan: Comparing the State and Private Sector

ERIC Educational Resources Information Center

Siddiqui, Nadia

2017-01-01

The distribution of children in different school-types and regions in Pakistan suggests that access and opportunities in education are not evenly accessible for many children. Segregation at school level is an important concern for equity and social justice because the adverse effects of segregation increase the pre-existing gap in opportunities…

46 CFR 154.305 - Segregation of hold spaces from the sea.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Segregation of hold spaces from the sea. 154.305 Section... Equipment Ship Arrangements § 154.305 Segregation of hold spaces from the sea. In vessels having cargo... sea by: (a) A double bottom if the cargo tanks meet this part for design temperatures colder than −10...

46 CFR 154.305 - Segregation of hold spaces from the sea.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Segregation of hold spaces from the sea. 154.305 Section... Equipment Ship Arrangements § 154.305 Segregation of hold spaces from the sea. In vessels having cargo... sea by: (a) A double bottom if the cargo tanks meet this part for design temperatures colder than −10...

46 CFR 154.305 - Segregation of hold spaces from the sea.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Segregation of hold spaces from the sea. 154.305 Section... Equipment Ship Arrangements § 154.305 Segregation of hold spaces from the sea. In vessels having cargo... sea by: (a) A double bottom if the cargo tanks meet this part for design temperatures colder than −10...

46 CFR 154.305 - Segregation of hold spaces from the sea.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Segregation of hold spaces from the sea. 154.305 Section... Equipment Ship Arrangements § 154.305 Segregation of hold spaces from the sea. In vessels having cargo... sea by: (a) A double bottom if the cargo tanks meet this part for design temperatures colder than −10...

46 CFR 154.305 - Segregation of hold spaces from the sea.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Segregation of hold spaces from the sea. 154.305 Section... Equipment Ship Arrangements § 154.305 Segregation of hold spaces from the sea. In vessels having cargo... sea by: (a) A double bottom if the cargo tanks meet this part for design temperatures colder than −10...

The Legacy Effect: Understanding How Segregation and Environmental Injustice Unfold over Time in Baltimore

Treesearch

Morgan Grove; Laura Ogden; Steward Pickett; Chris Boone; Geoff Buckley; Dexter H. Locke; Charlie Lord; Billy Hall

2018-01-01

Legacies of social and environmental injustices can leave an imprint on the present and constrain transitions for more sustainable futures. In this article, we ask this question: What is the relationship of environmental inequality and histories of segregation? The answer for Baltimore is complex, where past practices of de jure and de facto segregation have created...

The Effect of High School Socioeconomic, Racial, and Linguistic Segregation on Academic Performance and School Behaviors

ERIC Educational Resources Information Center

Palardy, Gregory J.; Rumberger, Russell W.; Butler, Truman

2015-01-01

Background/Context: The 1954 U.S. Supreme Court decision on Brown v. Board of Education concluded that segregated schools were inherently unequal and therefore unlawful. That decision was not based solely upon the notion that segregated black schools were inferior in terms of academic instruction, curricular rigor, resources, etc., but also on…

Children's Cross-Ethnic Relationships in Elementary Schools: Concurrent and Prospective Associations between Ethnic Segregation and Social Status

ERIC Educational Resources Information Center

Wilson, Travis M.; Rodkin, Philip C.

2013-01-01

This study examined whether ethnic segregation is concurrently (fall) and prospectively (fall to spring) associated with social status among 4th- and 5th-grade African American and European American children ("n" = 713, ages 9-11 years). Segregation measures were (a) same-ethnicity favoritism in peer affiliations and (b) cross-ethnicity…

From Resegregation to Reintegration: Trends in the Racial/Ethnic Segregation of Metropolitan Public Schools, 1993-2009

ERIC Educational Resources Information Center

Stroub, Kori J.; Richards, Meredith P.

2013-01-01

Considerable attention has been devoted to the resegregation of public schools over the 1990s. No research to date, however, has examined change in school segregation since 2000. Using the National Center for Education Statistics (NCES) Common Core of Data (CCD), we examine longitudinal trends in racial/ethnic segregation in 350 U.S. metropolitan…

The Company They Keep and Avoid: Social Goal Orientation as a Predictor of Children's Ethnic Segregation

ERIC Educational Resources Information Center

Wilson, Travis M.; Rodkin, Philip C.; Ryan, Allison M.

2014-01-01

This study examined whether social goal orientation (i.e., demonstration-approach, demonstration--avoid, and social development goals) predicts changes in ethnic segregation among 4th and 5th grade African American and European American children (n = 713, ages 9-11 years) from fall to spring. Segregation measures were (a) same-ethnicity favoritism…

The Saudi Arabian International Student Experience: From a Gender-Segregated Society to Studying in a Mixed-Gender Environment

ERIC Educational Resources Information Center

Alhazmi, Ahmed; Nyland, Berenice

2013-01-01

In Saudi Arabia gender segregation is a cultural practice that occurs across all public and private domains. This segregation has shaped the lives of Saudi citizens and is driven socially through cultural and religious discourses and politically through regulation and policy. For Saudi students undertaking their education in western countries, the…

Nearly 50 Years Post-Jim Crow: Persisting and Expansive School Segregation for African American, Latina/o, and ELL Students in Texas

ERIC Educational Resources Information Center

Vasquez Heilig, Julian; Holme, Jennifer Jellison

2013-01-01

This study addresses the segregation of English language learner (ELL) students in schools across Texas. We descriptively analyze levels of racial, economic, and linguistic isolation experienced by ELL students across the state of Texas. We also examine the association between segregation by race/ethnicity, economic disadvantage, and language…

The Struggle against Separate and Unequal Schools: Middle Class Mexican Americans and the Desegregation Campaign in Texas, 1929-1957.

ERIC Educational Resources Information Center

San Miguel, Guadalupe, Jr.

1983-01-01

Despite the efforts of Mexican American groups, such as the League of United Latin American Citizens and the G.I. Forum, and court orders to end segregation, schools in Texas continued to segregate Mexican American children. The political liberalism of these groups kept them from developing effective strategies against segregation. (IS)

Bridging the Achievement Gap in Urban Schools: Reducing Educational Segregation and Advancing Resilience--Promoting Strategies. Publication Series #95-9.

ERIC Educational Resources Information Center

Wang, Margaret C.; Kovach, John A.

The impact of the changing macroecological characteristics of cities on school performance is explored, and what can be done to reduce the achievement shortcomings among urban students from ethnic and language minority backgrounds is considered. The increase in residential segregation and thereby educational segregation in urban schools is as much…

Local Chain Segregation and Entanglements in a Confined Polymer Melt

NASA Astrophysics Data System (ADS)

Lee, Nam-Kyung; Diddens, Diddo; Meyer, Hendrik; Johner, Albert

2017-02-01

The reptation mechanism, introduced by de Gennes and Edwards, where a polymer diffuses along a fluffy tube, defined by the constraints imposed by its surroundings, convincingly describes the relaxation of long polymers in concentrated solutions and melts. We propose that the scale for the tube diameter is set by local chain segregation, which we study analytically. We show that the concept of local segregation is especially operational for confined geometries, where segregation extends over mesoscopic domains, drastically reducing binary contacts, and provide an estimate of the entanglement length. Our predictions are quantitatively supported by extensive molecular dynamics simulations on systems consisting of long, entangled chains.

From equator to pole: splitting chromosomes in mitosis and meiosis

PubMed Central

Duro, Eris

2015-01-01

During eukaryotic cell division, chromosomes must be precisely partitioned to daughter cells. This relies on a mechanism to move chromosomes in defined directions within the parental cell. While sister chromatids are segregated from one another in mitosis and meiosis II, specific adaptations enable the segregation of homologous chromosomes during meiosis I to reduce ploidy for gamete production. Many of the factors that drive these directed chromosome movements are known, and their molecular mechanism has started to be uncovered. Here we review the mechanisms of eukaryotic chromosome segregation, with a particular emphasis on the modifications that ensure the segregation of homologous chromosomes during meiosis I. PMID:25593304

Macrosegregation in aluminum alloy ingot cast by the semicontinuous direct chill method

NASA Technical Reports Server (NTRS)

Yu, H.; Granger, D. A.

1984-01-01

A theoretical model of the semicontinuous DC casting method is developed to predict the positive segregation observed at the subsurface and the negative segregation commonly found at the center of large commercial-size aluminum alloy ingot. Qualitative analysis of commercial-size aluminum alloy semicontinuous cast direct chill (DC) ingot is carried out. In the analysis, both positive segregation in the ingot subsurface and negative segregation at the center of the ingot are examined. Ingot subsurface macrosegregation is investigated by considering steady state casting of a circular cross-section binary alloy ingot. Nonequilibrium solidification is assumed with no solid diffusion, constant equilibrium partition ratio, and constant solid density.

Pd surface and Pt subsurface segregation in Pt1-c Pd c nanoalloys

NASA Astrophysics Data System (ADS)

De Clercq, A.; Giorgio, S.; Mottet, C.

2016-02-01

The structure and chemical arrangement of Pt1-c Pd c nanoalloys with the icosahedral and face centered cubic symmetry are studied using Monte Carlo simulations with a tight binding interatomic potential fitted to density-functional theory calculations. Pd surface segregation from the lowest to the highest coordinated sites is predicted by the theory together with a Pt enrichment at the subsurface, whatever the structure and the size of the nanoparticles, and which subsists when increasing the temperature. The onion-shell chemical configuration is found for both symmetries and is initiated from the Pd surface segregation. It is amplified in the icosahedral symmetry and small sizes but when considering larger sizes, the oscillating segregation profile occurs near the surface on about three to four shells whatever the structure. Pd segregation results from the significant lower cohesive energy of Pd as compared to Pt and the weak ordering tendency leads to the Pt subsurface segregation. The very weak size mismatch does not prevent the bigger atoms (Pt) from occupying subsurface sites which are in compression whereas the smaller ones (Pd) occupy the central site of the icosahedra where the compression is an order of magnitude higher.

Gender segregation as a benefit - a qualitative study from Pakistan.

PubMed

Rizvi Jafree, Sara; Zakar, Rubeena; Zakar, Muhammad Zakria

2015-11-01

To explore the possibility of exploiting gender segregation as a benefit for registered female nurses. Nursing is a highly gendered profession in Pakistan with 95% of nurses comprising females who suffer from low professional status, negative identity and unfavourable work environments. A qualitative research design was used to interview 12 nurses in management positions through purposive sampling. Face-to-face in-depth interviews were conducted to explore the views of female nurses on the benefits, if any, of gender segregation in the nursing profession. Content analysis identified three major categories of benefits of gender segregation for female nurses including: (1) demand for female nurses compared with demand for males, (2) resilience of female nurses in the face of difficult work environments and (3) comfort and safety of female co-workers in a male-dominated setting. Realising the benefits of gender segregation could mobilise nurse teamwork and union efforts in order to improve nurse identity, professional status and work environments. The present study highlights the nurse manager role in advancing knowledge of gender segregation benefits, team-building for gender solidarity, control of nurse supply, union mobilization and raising community awareness for women's health development. © 2014 John Wiley & Sons Ltd.

Nuclear envelope expansion is crucial for proper chromosomal segregation during a closed mitosis.

PubMed

Takemoto, Ai; Kawashima, Shigehiro A; Li, Juan-Juan; Jeffery, Linda; Yamatsugu, Kenzo; Elemento, Olivier; Nurse, Paul

2016-03-15

Here, we screened a 10,371 library of diverse molecules using a drug-sensitive fission yeast strain to identify compounds which cause defects in chromosome segregation during mitosis. We identified a phosphorium-ylide-based compound Cutin-1 which inhibits nuclear envelope expansion and nuclear elongation during the closed mitosis of fission yeast, and showed that its target is the β-subunit of fatty acid synthase. A point mutation in the dehydratase domain of Fas1 conferred in vivo and in vitro resistance to Cutin-1. Time-lapse photomicrography showed that the bulk of the chromosomes were only transiently separated during mitosis, and nucleoli separation was defective. Subsequently sister chromatids re-associated leading to chromosomal mis-segregation. These segregation defects were reduced when the nuclear volume was increased and were increased when the nuclear volume was reduced. We propose that there needs to be sufficient nuclear volume to allow the nuclear elongation necessary during a closed mitosis to take place for proper chromosome segregation, and that inhibition of fatty acid synthase compromises nuclear elongation and leads to defects in chromosomal segregation. © 2016. Published by The Company of Biologists Ltd.

Understanding Trends in Concentrated Poverty: 1980 to 2014*

PubMed Central

Iceland, John; Hernandez, Erik

2016-01-01

Trends in concentrated neighborhood poverty in the United States have been volatile over the past several decades. Using data from the 1980 to 2000 decennial census and the 2010-2014 American Community Survey, we examine the association between concentrated poverty across metropolitan areas in the United States and key proximate factors, including overall changes in poverty, racial residential segregation, and income segregation. One of our unique contributions is assessing the relative contribution of each of these to long-term trends in such poverty using a decomposition analysis. We find that changes in the segregation of the poor explained the largest share of the change in concentrated poverty over most of the time period, with the exception of the 1990s, where the plunge in both black and white poverty rates had the largest role in explaining the considerable decline in concentrated poverty in that decade for both groups. The association between racial segregation and black concentrated poverty is positive but weaker, indicating that without declines in black segregation, concentrated poverty would have been higher. Overall, growing income segregation, along with weak economic performance in recent years, have put more poor people at risk for living in high-poverty communities. PMID:28126115

The Association Between County-Level Injury Rates and Racial Segregation Revisited: A Multilevel Analysis

PubMed Central

Sauber-Schatz, Erin K.; Barbour, Kamil E.; Li, Wei

2009-01-01

Objectives. We investigated whether within-county racial segregation was associated with increased odds of violent injury beyond individual risk. Methods. In a cross-sectional study, data on 75 310 patients admitted with an injury to Pennsylvania hospitals from 1997 to 1999 were analyzed to determine the association between county-level racial segregation and violent injury. We used multilevel analysis to adjust for individual- and county-level factors. Principal components analysis allowed us to separate the effect of segregation from other county-level variables. Results. After adjustment, greater segregation was associated with increased odds of violent injury among Whites (odds ratio [OR] = 1.20; 95% confidence interval [CI] = 1.11, 1.30) and non-Whites (OR = 1.45; 95% CI = 1.28, 1.64). The association was stronger for non-Whites. Conclusions. Our results suggested that living in a county with high levels of racial segregation was associated with increased odds of violence not explained by an individual's own risk. These findings represent an important step in understanding the nature of observed links between race and violence. Future work should develop prevention strategies that simultaneously target community and individual risks. PMID:19150902

Evaluation of an education and training intervention to reduce health care waste in a tertiary hospital in Spain.

PubMed

Mosquera, Margarita; Andrés-Prado, Maria José; Rodríguez-Caravaca, Gil; Latasa, Pello; Mosquera, Marta E G

2014-08-01

In recent decades there has been a significant increase in waste generation. Training interventions in advanced health care waste management can improve the segregation of regulated medical waste and reduce volume and costs. We carried out a quasi-experimental intervention study with before and after training session analysis to compare waste segregation. Descriptive analysis of the segregated health care waste and an evaluation of the quality of segregation were done. A comparison of monthly average waste to assess the effectiveness of the educational intervention was performed. After the intervention, there was a significant reduction in the monthly average health care waste volume of 6.2%. Statistically significant differences in the infectious waste and genotoxic/pharmaceutical waste weight segregated before and after the intervention (P < .05) were found. Because of the health care waste weight reduction and the improvement of waste classification, a savings cost of €125,205 was achieved. The health care waste management training improves biomedical waste segregation at the hospital, reducing the health care waste volume and costs as an added value. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Sexual segregation in North American elk: the role of density dependence

PubMed Central

Stewart, Kelley M; Walsh, Danielle R; Kie, John G; Dick, Brian L; Bowyer, R Terry

2015-01-01

We investigated how density-dependent processes and subsequent variation in nutritional condition of individuals influenced both timing and duration of sexual segregation and selection of resources. During 1999–2001, we experimentally created two population densities of North American elk (Cervus elaphus), a high-density population at 20 elk/km2, and a low-density population at 4 elk/km2 to test hypotheses relative to timing and duration of sexual segregation and variation in selection of resources. We used multi-response permutation procedures to investigate patterns of sexual segregation, and resource selection functions to document differences in selection of resources by individuals in high- and low-density populations during sexual segregation and aggregation. The duration of sexual segregation was 2 months longer in the high-density population and likely was influenced by individuals in poorer nutritional condition, which corresponded with later conception and parturition, than at low density. Males and females in the high-density population overlapped in selection of resources to a greater extent than in the low-density population, probably resulting from density-dependent effects of increased intraspecific competition and lower availability of resources. PMID:25691992

Feedforward and recurrent processing in scene segmentation: electroencephalography and functional magnetic resonance imaging.

PubMed

Scholte, H Steven; Jolij, Jacob; Fahrenfort, Johannes J; Lamme, Victor A F

2008-11-01

In texture segregation, an example of scene segmentation, we can discern two different processes: texture boundary detection and subsequent surface segregation [Lamme, V. A. F., Rodriguez-Rodriguez, V., & Spekreijse, H. Separate processing dynamics for texture elements, boundaries and surfaces in primary visual cortex of the macaque monkey. Cerebral Cortex, 9, 406-413, 1999]. Neural correlates of texture boundary detection have been found in monkey V1 [Sillito, A. M., Grieve, K. L., Jones, H. E., Cudeiro, J., & Davis, J. Visual cortical mechanisms detecting focal orientation discontinuities. Nature, 378, 492-496, 1995; Grosof, D. H., Shapley, R. M., & Hawken, M. J. Macaque-V1 neurons can signal illusory contours. Nature, 365, 550-552, 1993], but whether surface segregation occurs in monkey V1 [Rossi, A. F., Desimone, R., & Ungerleider, L. G. Contextual modulation in primary visual cortex of macaques. Journal of Neuroscience, 21, 1698-1709, 2001; Lamme, V. A. F. The neurophysiology of figure ground segregation in primary visual-cortex. Journal of Neuroscience, 15, 1605-1615, 1995], and whether boundary detection or surface segregation signals can also be measured in human V1, is more controversial [Kastner, S., De Weerd, P., & Ungerleider, L. G. Texture segregation in the human visual cortex: A functional MRI study. Journal of Neurophysiology, 83, 2453-2457, 2000]. Here we present electroencephalography (EEG) and functional magnetic resonance imaging data that have been recorded with a paradigm that makes it possible to differentiate between boundary detection and scene segmentation in humans. In this way, we were able to show with EEG that neural correlates of texture boundary detection are first present in the early visual cortex around 92 msec and then spread toward the parietal and temporal lobes. Correlates of surface segregation first appear in temporal areas (around 112 msec) and from there appear to spread to parietal, and back to occipital areas. After 208 msec, correlates of surface segregation and boundary detection also appear in more frontal areas. Blood oxygenation level-dependent magnetic resonance imaging results show correlates of boundary detection and surface segregation in all early visual areas including V1. We conclude that texture boundaries are detected in a feedforward fashion and are represented at increasing latencies in higher visual areas. Surface segregation, on the other hand, is represented in "reverse hierarchical" fashion and seems to arise from feedback signals toward early visual areas such as V1.

Feedback effect of base roughness on particle size segregation in bidisperse granular avalanche

NASA Astrophysics Data System (ADS)

Jing, L.; Kwok, F.

2017-12-01

Particle size segregation in a geophysical flow interplays with base roughness, leading to rich behaviors such as bouldery front formation and fingering instability. The interplay originates mainly from the fact that larger particles slip more easily on a slope, the slip affects the progress of segregation, and segregation changes the size of particles contacting the slope. Recent studies show that slip velocity scales with geometric roughness (which involves both the size and spacing of base particles), and the roughness becomes a function of time during segregation. However, at least two questions remain unanswered: 1) In addition to geometric roughness, what is the role of mechanical parameters at boundaries? 2) To what extent the findings from steady flows are valid in a transient system, which is more common in actual geophysical flows? Here we study two configurations using the discrete element method, the first being a steady flow with periodic boundaries, where we vary the size, spatial arrangement, and contact parameters of base particles. The second consists in dambreak-type bidisperse granular avalanches over inclined planes, where the degree of segregation, base roughness, flow thickness, and base velocity are measured locally as the flow evolves. We found that: 1) On a frictional plane in the absence of geometric roughness, the friction parameter μ controls the amount of basal slip. A lower μ leads to a slower segregation. 2) On a bumpy base with low geometric roughness (where slip still occurs), the effect of μ becomes marginal, while the coefficient of restitution e controls the slip velocity; this indicates the significance of normal collision in the working mechanism of a bumpy base. Upon sliding, large particles near the base may exhibit an ordered state where shear is poorly developed, which delays the onset of segregation. 3) Both μ and e have no influence when the geometric roughness is sufficient to sustain a nonslip condition. Our results suggest the feedback effect of base roughness on segregation, which has a theoretical significance in the boundary treatment when modeling geophysical flows. The study also shows the possibility to establish a universal scaling law correlating slip velocity, base roughness, and the degree of segregation in both steady and unsteady flows.

Light and Electrically Induced Phase Segregation and Its Impact on the Stability of Quadruple Cation High Bandgap Perovskite Solar Cells.

PubMed

Duong, The; Mulmudi, Hemant Kumar; Wu, YiLiang; Fu, Xiao; Shen, Heping; Peng, Jun; Wu, Nandi; Nguyen, Hieu T; Macdonald, Daniel; Lockrey, Mark; White, Thomas P; Weber, Klaus; Catchpole, Kylie

2017-08-16

Perovskite material with a bandgap of 1.7-1.8 eV is highly desirable for the top cell in a tandem configuration with a lower bandgap bottom cell, such as a silicon cell. This can be achieved by alloying iodide and bromide anions, but light-induced phase-segregation phenomena are often observed in perovskite films of this kind, with implications for solar cell efficiency. Here, we investigate light-induced phase segregation inside quadruple-cation perovskite material in a complete cell structure and find that the magnitude of this phenomenon is dependent on the operating condition of the solar cell. Under short-circuit and even maximum power point conditions, phase segregation is found to be negligible compared to the magnitude of segregation under open-circuit conditions. In accordance with the finding, perovskite cells based on quadruple-cation perovskite with 1.73 eV bandgap retain 94% of the original efficiency after 12 h operation at the maximum power point, while the cell only retains 82% of the original efficiency after 12 h operation at the open-circuit condition. This result highlights the need to have standard methods including light/dark and bias condition for testing the stability of perovskite solar cells. Additionally, phase segregation is observed when the cell was forward biased at 1.2 V in the dark, which indicates that photoexcitation is not required to induce phase segregation.

Metropolitan isolation segregation and Black-White disparities in very preterm birth: a test of mediating pathways and variance explained.

PubMed

Kramer, Michael R; Cooper, Hannah L; Drews-Botsch, Carolyn D; Waller, Lance A; Hogue, Carol R

2010-12-01

Residential isolation segregation (a measure of residential inter-racial exposure) has been associated with rates of preterm birth (<37 weeks gestation) experienced by Black women. Epidemiologic differences between very preterm (<32 weeks gestation) and moderately preterm births (32-36 weeks) raise questions about whether this association is similar across gestational ages, and through what pathways it might be mediated. Hierarchical Bayesian models were fit to answer three questions: is the isolation-prematurity association similar for very and moderately preterm birth; is this association mediated by maternal chronic disease, socioeconomic status, or metropolitan area crime and poverty rates; and how much of the geographic variation in Black-White very preterm birth disparities is explained by isolation segregation? Singleton births to Black and White women in 231 U.S. metropolitan statistical areas in 2000-2002 were analyzed and isolation segregation was calculated for each. We found that among Black women, isolation is associated with very preterm birth and moderately preterm birth. The association may be partially mediated by individual level socioeconomic characteristics and metropolitan level violent crime rates. There is no association between segregation and prematurity among White women. Isolation segregation explains 28% of the geographic variation in Black-White very preterm birth disparities. Our findings highlight the importance of isolation segregation for the high-burden outcome of very preterm birth, but unexplained excess risk for prematurity among Black women is substantial. Copyright © 2010 Elsevier Ltd. All rights reserved.

Dbl2 Regulates Rad51 and DNA Joint Molecule Metabolism to Ensure Proper Meiotic Chromosome Segregation

PubMed Central

Hyppa, Randy W.; Benko, Zsigmond; Misova, Ivana; Schleiffer, Alexander; Smith, Gerald R.; Gregan, Juraj

2016-01-01

To identify new proteins required for faithful meiotic chromosome segregation, we screened a Schizosaccharomyces pombe deletion mutant library and found that deletion of the dbl2 gene led to missegregation of chromosomes during meiosis. Analyses of both live and fixed cells showed that dbl2Δ mutant cells frequently failed to segregate homologous chromosomes to opposite poles during meiosis I. Removing Rec12 (Spo11 homolog) to eliminate meiotic DNA double-strand breaks (DSBs) suppressed the segregation defect in dbl2Δ cells, indicating that Dbl2 acts after the initiation of meiotic recombination. Analyses of DSBs and Holliday junctions revealed no significant defect in their formation or processing in dbl2Δ mutant cells, although some Rec12-dependent DNA joint molecules persisted late in meiosis. Failure to segregate chromosomes in the absence of Dbl2 correlated with persistent Rad51 foci, and deletion of rad51 or genes encoding Rad51 mediators also suppressed the segregation defect of dbl2Δ. Formation of foci of Fbh1, an F-box helicase that efficiently dismantles Rad51-DNA filaments, was impaired in dbl2Δ cells. Our results suggest that Dbl2 is a novel regulator of Fbh1 and thereby Rad51-dependent DSB repair required for proper meiotic chromosome segregation and viable sex cell formation. The wide conservation of these proteins suggests that our results apply to many species. PMID:27304859

Optimal Integration of Departure and Arrivals in Terminal Airspace

NASA Technical Reports Server (NTRS)

Xue, Min; Zelinski, Shannon Jean

2012-01-01

Coordination of operations with spatially and temporally shared resources such as route segments, fixes, and runways improves the efficiency of terminal airspace management. Problems in this category include scheduling and routing, thus they are normally difficult to solve compared with pure scheduling problems. In order to reduce the computational time, a fast time algorithm formulation using a non-dominated sorting genetic algorithm (NSGA) was introduced in this work and applied to a test case based on existing literature. The experiment showed that new method can solve the whole problem in fast time instead of solving sub-problems sequentially with a window technique. The results showed a 60% or 406 second delay reduction was achieved by sharing departure fixes (more details on the comparison with MILP results will be presented in the final paper). Furthermore, the NSGA algorithm was applied to a problem in LAX terminal airspace, where interactions between 28% of LAX arrivals and 10% of LAX departures are resolved by spatial segregation, which may introduce unnecessary delays. In this work, spatial segregation, temporal segregation, and hybrid segregation were formulated using the new algorithm. Results showed that spatial and temporal segregation approaches achieved similar delay. Hybrid segregation introduced much less delay than the other two approaches. For a total of 9 interacting departures and arrivals, delay reduction varied from 4 minutes to 6.4 minutes corresponding flight time uncertainty from 0 to 60 seconds. Considering the amount of flights that could be affected, total annual savings with hybrid segregation would be significant.

Segregation and Poverty Concentration: The Role of Three Segregations

PubMed Central

Quillian, Lincoln

2014-01-01

A key argument of Massey and Denton’s American Apartheid (1993) is that racial residential segregation and non-white group poverty rates combine interactively to produce spatially concentrated poverty. Despite a compelling theoretical rationale, the empirical tests of this proposition have been negative or mixed. This paper develops a formal decomposition model that expands the Massey model of how segregation, group poverty rates, and other spatial conditions combine to form concentrated poverty. The revised decomposition model allows for income effects on cross-race neighborhood residence and interactive combinations of multiple spatial conditions in the formation of concentrated poverty. Applying the model to data reveals that racial segregation and income segregation within race contribute importantly to poverty concentration, as Massey argued, but that almost equally important for poverty concentration is the disproportionate poverty of the non-group neighbors of blacks and Hispanics. The missing interaction Massey expected in empirical tests can be found with proper accounting for the factors in the expanded model. “Because of racial segregation, a significant share of black America is condemned to experience a social environment where poverty and joblessness are the norm, where a majority of children are born out of wedlock, where most families are on welfare, where educational failure prevails, and where social and physical deterioration abound. Through prolonged exposure to such an environment, black chances for social and economic success are drastically reduced.”--Douglas Massey and Nancy Denton, American Apartheid, p. 2 PMID:24648570

Compositional redistribution in alloy films under high-voltage electron microscope irradiation

NASA Astrophysics Data System (ADS)

Lam, Nghi Q.; Leaf, O. K.; Minkoff, M.

1983-10-01

The problem of nonequilibrium segregation in alloy films under high-voltage electron microscope (HVEM) irradiation at elevated temperatures is re-examined in the present work, taking into account the damage-rate gradients caused by radial variation in the electron flux. Axial and radial compositional redistributions in model solid solutions, representative of concentrated Ni-Cu, Ni-Al and Ni-Si alloys, were calculated as a function of time, temperature, and film thickness, using a kinetic theory of segregation in binary alloys. The numerical results were achieved by means of a new software package (DISPL2) for solving convection-diffusion-kinetics problems with general orthogonal geometries. It was found that HVEM irradiation-induced segregation in thin films consists of two stages. Initially, due to the proximity of the film surfaces as sinks for point defects, the usual axial segregation (to surfaces) occurs at relatively short irradiation times, and rapidly attains quasi-steady state. Then, radial segregation becomes more and more competitive, gradually affecting the kinetics of axial segregation. At a given temperature, the buildup time to steady state is much longer in the present situation than in the simple case of one-dimensional segregation with uniform defect production. Changes in the alloy composition occur in a much larger zone than the irradiated volume. As a result, the average alloy composition within the irradiated region can differ greatly from that of the unirradiated alloy. The present calculations may be useful in the interpretation of the kinetics of certain HVEM irradiation-induced processes in alloys.

Effect of Segregation of Secondary Phase Particles and "S" Line on Tensile Fracture Behavior of Friction Stir-Welded 2024Al-T351 Joints

NASA Astrophysics Data System (ADS)

Zhang, Z.; Xiao, B. L.; Ma, Z. Y.

2013-09-01

A 5-mm-thick 2024Al-T351 plate was friction stir welded (FSWed) at welding speeds of 100, 200, and 400 mm min-1 with a constant rotation rate of 800 rpm, and the microstructure and tensile fracture behavior of the joints were investigated in detail. FSW resulted in the redistribution of secondary phase particles along the recrystallized grain boundaries at the nugget zone (NZ), forming linear segregation bands consisting of secondary phase particles. The segregation bands, mainly present in the shoulder-driven zone, were believed to result from periodic material flow, with the average band spacing on the longitudinal and horizontal cross sections equal to the tool advancement per revolution. At a low welding speed of 100 mm min-1, in spite of the highest density of segregation bands, the FSWed 2024Al-T351 joint fractured along the low hardness zone (LHZ) of the heat-affected zone because of large hardness gap between NZ and LHZ. Increasing the welding speed to 200 and 400 mm min-1 reduced both the hardness gap between NZ and LHZ and the density of segregation bands. In this case, the segregation bands played a role, resulting in unusual fracture of the joints along the segregation bands. The "S" line originated from the oxide film on the initial butting surfaces and did not affect the fracture behavior of the FSWed 2024Al-T351 joints.

Catenin-dependent cadherin function drives divisional segregation of spinal motor neurons.

PubMed

Bello, Sanusi M; Millo, Hadas; Rajebhosale, Manisha; Price, Stephen R

2012-01-11

Motor neurons that control limb movements are organized as a neuronal nucleus in the developing ventral horn of the spinal cord called the lateral motor column. Neuronal migration segregates motor neurons into distinct lateral and medial divisions within the lateral motor column that project axons to dorsal or ventral limb targets, respectively. This migratory phase is followed by an aggregation phase whereby motor neurons within a division that project to the same muscle cluster together. These later phases of motor neuron organization depend on limb-regulated differential cadherin expression within motor neurons. Initially, all motor neurons display the same cadherin expression profile, which coincides with the migratory phase of motor neuron segregation. Here, we show that this early, pan-motor neuron cadherin function drives the divisional segregation of spinal motor neurons in the chicken embryo by controlling motor neuron migration. We manipulated pan-motor neuron cadherin function through dissociation of cadherin binding to their intracellular partners. We found that of the major intracellular transducers of cadherin signaling, γ-catenin and α-catenin predominate in the lateral motor column. In vivo manipulations that uncouple cadherin-catenin binding disrupt divisional segregation via deficits in motor neuron migration. Additionally, reduction of the expression of cadherin-7, a cadherin predominantly expressed in motor neurons only during their migration, also perturbs divisional segregation. Our results show that γ-catenin-dependent cadherin function is required for spinal motor neuron migration and divisional segregation and suggest a prolonged role for cadherin expression in all phases of motor neuron organization.

Social Construction of a Segregated Urban Space and Its Effects on Education: A Case Study of the Balmikis of Delhi

ERIC Educational Resources Information Center

Ganguly, Sriti

2018-01-01

While segregation of Dalit habitations is assumed to be a characteristic primarily of the rural, studies indicate that a similar spatial organisation is reproduced in urban spaces as well where large populations, particularly of poor Dalits, continue to live in segregated settlements. This article draws on an exploratory study conducted in one…

Intelligibility of Target Signals in Sequential and Simultaneous Segregation Tasks

DTIC Science & Technology

2009-03-01

SUBJECT TERMS Informational masking; energetic masking, multimasker penalty, speech perception 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...alter- nation rates were high enough to directly interfere with the perception of the F0 values of the speech signals and that they thus disrupted the...segregation effects seen in this experiment and those in which stream segregation with tones was examined. Experiments examining the perception of

Segregation Levels in Milwaukee Public Schools and the Milwaukee Voucher Program. School Choice Issues in the State

ERIC Educational Resources Information Center

Forster, Greg

2006-01-01

This study compares segregation levels in Milwaukee public schools and in private schools participating in the Milwaukee voucher program. Using a segregation index that measures the difference between the percent of students in a school who are white and the percentage of school-age children in the greater metro area who are white, it finds that…

"In These Towns, Mexicans Are Classified as Negroes": The Politics of Unofficial Segregation in the Kansas Public Schools, 1915-1935

ERIC Educational Resources Information Center

Donato, Rubén; Hanson, Jarrod

2017-01-01

This article examines the emergence of Mexican American school segregation from 1915 to 1935 in Kansas, the state that gave rise to "Brown v. Board of Education" in 1954. Even though Mexicans were not referenced in Kansas's school segregation laws, they were seen and treated as a racially distinct group. White parents and civic…

46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Segregation of spaces containing the emergency source of electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... On or After July 1, 1951 § 32.60-45 Segregation of spaces containing the emergency source of electric...

46 CFR 32.60-45 - Segregation of spaces containing the emergency source of electric power-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Segregation of spaces containing the emergency source of electric power-TB/ALL. 32.60-45 Section 32.60-45 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK... On or After July 1, 1951 § 32.60-45 Segregation of spaces containing the emergency source of electric...

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

Samu, Gergely F.; Janaky, Csaba; Kamat, Prashant V.

Photoinduced segregation in mixed halide perovskites has a direct influence on decreasing the solar cell efficiency as segregated I-rich domains serve as charge recombination centers. Here, the changes in the external quantum efficiency mirror the spectral loss in the absorption; however, the time scale of the IPCE recovery in the dark is slower than the absorption recovery, showing the intricate nature of the photoinduced halide segregation and charge collection in solar cell devices.

Residential Segregation by Race in U.S. Metropolitan Areas: An Analysis Across Cities and Over Time.

ERIC Educational Resources Information Center

Schnare, Ann B.

There is a need to understand more clearly the forces that work to generate and maintain a segregated housing market. There is also a need to formulate statistical measures of segregation, so that developments in future years can be assessed against the past. This report was designed with these two objectives in mind. The analysis is primarily…

A Comparison of Segregation Indices Used for Assessing the Socio-Economic Composition of Schools. Measuring Markets: The Case of the ERA 1988. Working Paper.

ERIC Educational Resources Information Center

Gorard, Stephen; Taylor, Chris

This paper examines the changing socioeconomic composition of English and Welsh schools over 11 years following the Education Reform Act of 1988, using many indicators of socioeconomic disadvantage and methods of measuring the changing spread of disadvantage among schools (segregation). It explains how to assess segregation (percentage differences…

Meiotic and pedigree segregation analyses in carriers of t(4;8)(p16;p23.1) differing in localization of breakpoint positions at 4p subband 4p16.3 and 4p16.1.

PubMed

Midro, Alina T; Zollino, Marcella; Wiland, Ewa; Panasiuk, Barbara; Iwanowski, Piotr S; Murdolo, Marina; Śmigiel, Robert; Sąsiadek, Maria; Pilch, Jacek; Kurpisz, Maciej

2016-02-01

The purpose of this study was to compare meiotic segregation in sperm cells from two carriers with t(4;8)(p16;p23.1) reciprocal chromosome translocations (RCTs), differing in localization of the breakpoint positions at the 4p subband-namely, 4p16.3 (carrier 1) and 4p16.1 (carrier 2)-and to compare data of the pedigree analyses performed by direct method. Three-color fluorescent in situ hybridization (FISH) on sperm cells and FISH mapping for the evaluation of the breakpoint positions, data from pedigrees, and direct segregation analysis of the pedigrees were performed. Similar proportions of normal/balanced and unbalanced sperm cells were found in both carriers. The most common was an alternate type of segregation (about 52 % and about 48 %, respectively). Unbalanced adjacent I and adjacent II karyotypes were found in similar proportions about 15 %. The direct segregation analysis (following Stengel-Rutkowski) of the pedigree of carriers of t(4;8)(p16.1;p23.1) was performed and results were compared with the data of the pedigree segregation analysis obtained earlier through the indirect method. The probability of live-born progeny with unbalanced karyotype for carriers of t(4;8)(p16.1;p23.1) was moderately high at 18.8 %-comparable to the value obtained using the indirect method for the same carriership, which was 12 %. This was, however, markedly lower than the value of 41.2 % obtained through the pedigree segregation indirect analysis estimated for carriers of t(4;8)(p16.3;p23.1), perhaps due to the unique composition of genes present within the 4p16.1-4p 16.3 region. Revealed differences in pedigree segregation analysis did not correspond to the very similar profile of meiotic segregation patterns presented by carrier 1 and carrier 2. Most probably, such discordances may be due to differences in embryo survival rates arising from different genetic backgrounds.

Towards wall functions for the prediction of solute segregation in plane front directional solidification

NASA Astrophysics Data System (ADS)

Chatelain, M.; Rhouzlane, S.; Botton, V.; Albaric, M.; Henry, D.; Millet, S.; Pelletier, D.; Garandet, J. P.

2017-10-01

The present paper focuses on solute segregation occurring in directional solidification processes with sharp solid/liquid interface, like silicon crystal growth. A major difficulty for the simulation of such processes is their inherently multi-scale nature: the impurity segregation problem is controlled at the solute boundary layer scale (micrometers) while the thermal problem is ruled at the crucible scale (meters). The thickness of the solute boundary layer is controlled by the convection regime and requires a specific refinement of the mesh of numerical models. In order to improve numerical simulations, wall functions describing solute boundary layers for convecto-diffusive regimes are derived from a scaling analysis. The aim of these wall functions is to obtain segregation profiles from purely thermo-hydrodynamic simulations, which do not require solute boundary layer refinement at the solid/liquid interface. Regarding industrial applications, various stirring techniques can be used to enhance segregation, leading to fully turbulent flows in the melt. In this context, the scaling analysis is further improved by taking into account the turbulent solute transport. The solute boundary layers predicted by the analytical model are compared to those obtained by transient segregation simulations in a canonical 2D lid driven cavity configuration for validation purposes. Convective regimes ranging from laminar to fully turbulent are considered. Growth rate and molecular diffusivity influences are also investigated. Then, a procedure to predict concentration fields in the solid phase from a hydrodynamic simulation of the solidification process is proposed. This procedure is based on the analytical wall functions and on solute mass conservation. It only uses wall shear-stress profiles at the solidification front as input data. The 2D analytical concentration fields are directly compared to the results of the complete simulation of segregation in the lid driven cavity configuration. Finally, an additional output from the analytical model is also presented. We put in light the correlation between different species convecto-diffusive behaviour; we use it to propose an estimation method for the segregation parameters of various chemical species knowing segregation parameters of one specific species.

DEM simulation of the granular Maxwell's Demon under zero gravity

NASA Astrophysics Data System (ADS)

Wang, Wenguang; Zhou, Zhigang; Zong, Jin; Hou, Meiying

2017-06-01

In this work, granular segregation in a two-compartment cell (Maxwell's Demon) under zero gravity is studied numerically by DEM simulation for comparison with the experimental observation in satellite SJ-10. The effect of three parameters: the total number of particlesN, the excitation strengthΓ, and the position of the window coupling the two compartments, on the segregationɛ and the waiting timeτ are investigated. In the simulation, non-zero segregation under zero gravity is obtained, and the segregation ɛ is found independent of the excitation strengthΓ. The waiting time τ, however, depends strongly onΓ. For higher acceleration Γ, |ɛi| reaches steady state valueɛ faster.

Heats of Segregation of BCC Binaries from ab Initio and Quantum Approximate Calculations

NASA Technical Reports Server (NTRS)

Good, Brian S.

2004-01-01

We compare dilute-limit heats of segregation for selected BCC transition metal binaries computed using ab initio and quantum approximate energy methods. Ab initio calculations are carried out using the CASTEP plane-wave pseudopotential computer code, while quantum approximate results are computed using the Bozzolo-Ferrante-Smith (BFS) method with the most recent LMTO-based parameters. Quantum approximate segregation energies are computed with and without atomistic relaxation, while the ab initio calculations are performed without relaxation. Results are discussed within the context of a segregation model driven by strain and bond-breaking effects. We compare our results with full-potential quantum calculations and with available experimental results.

SEMICONDUCTOR TECHNOLOGY: SBH adjustment characteristic of the dopant segregation process for NiSi/n-Si SJDs

NASA Astrophysics Data System (ADS)

Haiping, Shang; Qiuxia, Xu

2010-05-01

By means of analyzing the I-V characteristic curve of NiSi/n-Si Schottky junction diodes (NiSi/n-Si SJDs), abstracting the effective Schottky barrier height (varphiB, eff) and the ideal factor of NiSi/n-Si SJDs and measuring the sheet resistance of NiSi films (RNiSi), we study the effects of different dopant segregation process parameters, including impurity implantation dose, segregation annealing temperature and segregation annealing time, on the varphiB, eff of NiSi/n-Si SJDs and the resistance characteristic of NiSi films. In addition, the changing rules of varphiB, eff and RNiSi are discussed.

Density-functional study on the dopant-segregation mechanism: Chemical potential dependence of dopant-defect complex at Si/SiO2 interface

NASA Astrophysics Data System (ADS)

Kawai, Hiroki; Nakasaki, Yasushi; Kanemura, Takahisa; Ishihara, Takamitsu

2018-04-01

Dopant segregation at Si/SiO2 interface has been a serious problem in silicon device technology. This paper reports a comprehensive density-functional study on the segregation mechanisms of boron, phosphorous, and arsenic at the Si/SiO2 interface. We found that three kinds of interfacial defects, namely, interstitial oxygen, oxygen vacancy, and silicon vacancy with two oxygen atoms, are stable in the possible chemical potential range. Thus, we consider these defects as trap sites for the dopants. For these defects, the dopant segregation energies, the electrical activities of the trapped dopants, and the kinetic energy barriers of the trapping/detrapping processes are calculated. As a result, trapping at the interstitial oxygen site is indicated to be the most plausible mechanism of the dopant segregation. The interstitial oxygen works as a major trap site since it has a high areal density at the Si/SiO2 interface due to the low formation energy.

Uneven segregation of sporophytic self-incompatibility alleles in Arabidopsis lyrata.

PubMed

Bechsgaard, J; Bataillon, T; Schierup, M H

2004-05-01

Self-incompatibility in Arabidopsis lyrata is sporophytically controlled by the multi-allelic S-locus. Self-incompatibility alleles (S-alleles) are under strong negative frequency dependent selection because pollen carrying common S-alleles have fewer mating opportunities. Population genetics theory predicts that deleterious alleles can accumulate if linked to the S-locus. This was tested by studying segregation of S-alleles in 11 large full sib families in A. lyrata. Significant segregation distortion leading to an up to fourfold difference in transmission rates was found in six families. Differences in transmission rates were not significantly different in reciprocal crosses and the distortions observed were compatible with selection acting at the gametic stage alone. The S-allele with the largest segregation advantage is also the most recessive, and is very common in natural populations concordant with its apparent segregation advantage. These results imply that frequencies of S-alleles in populations of A. lyrata cannot be predicted based on simple models of frequency-dependent selection alone.

Redefining Racial Residential Segregation and its Association With Physical Activity Among African Americans 50 years and Older: A Mixed Methods Approach

PubMed Central

Armstrong-Brown, Janelle; Eng, Eugenia; Hammond, Wizdom Powell; Zimmer, Catherine; Bowling, J. Michael

2016-01-01

Physical inactivity is one of the factors contributing to disproportionate disease rates among older African Americans. Previous literature indicates that older African Americans are more likely to live in racially segregated neighborhoods and that racial residential segregation is associated with limited opportunities for physical activity. A cross-sectional mixed methods study was conducted guided by the concept of therapeutic landscapes. Multilevel regression analyses demonstrated that racial residential segregation was associated with more minutes of physical activity and greater odds of meeting physical activity recommendations. Qualitative interviews revealed the following physical activity related themes: aging of the neighborhood, knowing your neighbors, feeling of safety, and neighborhood racial identity. Perceptions of social cohesion enhanced participants’ physical activity, offering a plausible explanation to the higher rates of physical activity found in this population. Understanding how social cohesion operates within racially segregated neighborhoods can help to inform the design of effective interventions for this population. PMID:24812201

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

Vazehrad, S., E-mail: vazehrad@kth.se; Elfsberg, J., E-mail: jessica.elfsberg@scania.com; Diószegi, A., E-mail: attila.dioszegi@jth.hj.se

An investigation on silicon segregation of lamellar, compacted and nodular graphite iron was carried out by applying a selective, immersion color etching and a modified electron microprobe to study the microstructure. The color etched micrographs of the investigated cast irons by revealing the austenite phase have provided data about the chronology and mechanism of microstructure formation. Moreover, electron microprobe has provided two dimensional segregation maps of silicon. A good agreement was found between the segregation profile of silicon in the color etched microstructure and the silicon maps achieved by electron microprobe analysis. However, quantitative silicon investigation was found to bemore » more accurate than color etching results to study the size of the eutectic colonies. - Highlights: • Sensitivity of a color etchant to silicon segregation is quantitatively demonstrated. • Si segregation measurement by EMPA approved the results achieved by color etching. • Color etched micrographs provided data about solidification mechanism in cast irons. • Austenite grain boundaries were identified by measuring the local Si concentration.« less