Male group size, female distribution and changes in sexual segregation by Roosevelt elk

PubMed Central

Peterson, Leah M.

2017-01-01

Sexual segregation, or the differential use of space by males and females, is hypothesized to be a function of body size dimorphism. Sexual segregation can also manifest at small (social segregation) and large (habitat segregation) spatial scales for a variety of reasons. Furthermore, the connection between small- and large-scale sexual segregation has rarely been addressed. We studied a population of Roosevelt elk (Cervus elaphus roosevelti) across 21 years in north coastal California, USA, to assess small- and large-scale sexual segregation in winter. We hypothesized that male group size would associate with small-scale segregation and that a change in female distribution would associate with large-scale segregation. Variation in forage biomass might also be coupled to small and large-scale sexual segregation. Our findings were consistent with male group size associating with small-scale segregation and a change in female distribution associating with large-scale segregation. Females appeared to avoid large groups comprised of socially dominant males. Males appeared to occupy a habitat vacated by females because of a wider forage niche, greater tolerance to lethal risks, and, perhaps, to reduce encounters with other elk. Sexual segregation at both spatial scales was a poor predictor of forage biomass. Size dimorphism was coupled to change in sexual segregation at small and large spatial scales. Small scale segregation can seemingly manifest when all forage habitat is occupied by females and large scale segregation might happen when some forage habitat is not occupied by females. PMID:29121076

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

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.

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.

Atom probe study of grain boundary segregation in technically pure molybdenum

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

Babinsky, K., E-mail: katharina.babinsky@stud.unileoben.ac.at; Weidow, J., E-mail: jonathan.weidow@chalmers.se; Knabl, W., E-mail: wolfram.knabl@plansee.com

2014-01-15

Molybdenum, a metal with excellent physical, chemical and high-temperature properties, is an interesting material for applications in lighting-technology, high performance electronics, high temperature furnace construction and coating technology. However, its applicability as a structural material is limited because of the poor oxidation resistance at high temperatures and a brittle-to-ductile transition around room temperature, which is influenced by the grain size and the content of interstitial impurities at the grain boundaries. Due to the progress of the powder metallurgical production during the last decades, the amount of impurities in the current quality of molybdenum has become so small that surface sensitivemore » techniques are not applicable anymore. Therefore, the atom probe, which allows the detection of small amounts of impurities as well as their location, seems to be a more suitable technique. However, a site-specific specimen preparation procedure for grain boundaries in refractory metals with a dual focused ion beam/scanning electron microscope is still required. The present investigation describes the development and successful application of such a site-specific preparation technique for grain boundaries in molybdenum, which is significantly improved by a combination with transmission electron microscopy. This complimentary technique helps to improve the visibility of grain boundaries during the last preparation steps and to evidence the presence of grain and subgrain boundaries without segregants in atom probe specimens. Furthermore, in industrially processed and recrystallized molybdenum sheets grain boundary segregation of oxygen, nitrogen and potassium is successfully detected close to segregated regions which are believed to be former sinter pores. - Highlights: • First study of grain boundary segregation in molybdenum by atom probe • Site-specific preparation technique by FIB and TEM successfully developed • Grain boundary segregation of oxygen, nitrogen and potassium found • Segregation in former sinter-pores detected • Presence of grain boundaries without segregation evidenced.« less

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.

The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers.

PubMed

Yang, Shi Ying; Saxena, Rachit K; Kulwal, Pawan L; Ash, Gavin J; Dubey, Anuja; Harper, John D I; Upadhyaya, Hari D; Gothalwal, Ragini; Kilian, Andrzej; Varshney, Rajeev K

2011-04-01

With an objective to develop a genetic map in pigeon pea (Cajanus spp.), a total of 554 diversity arrays technology (DArT) markers showed polymorphism in a pigeon pea F(2) mapping population of 72 progenies derived from an interspecific cross of ICP 28 (Cajanus cajan) and ICPW 94 (Cajanus scarabaeoides). Approximately 13% of markers did not conform to expected segregation ratio. The total number of DArT marker loci segregating in Mendelian manner was 405 with 73.1% (P > 0.001) of DArT markers having unique segregation patterns. Two groups of genetic maps were generated using DArT markers. While the maternal genetic linkage map had 122 unique DArT maternal marker loci, the paternal genetic linkage map has a total of 172 unique DArT paternal marker loci. The length of these two maps covered 270.0 cM and 451.6 cM, respectively. These are the first genetic linkage maps developed for pigeon pea, and this is the first report of genetic mapping in any grain legume using diversity arrays technology.

Alloy formation and metal oxide segregation on Pt-Re/. gamma. -Al/sub 2/O/sub 3/ catalysts as investigated by temperature-programmed reduction

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

Wagstaff, N.; Prins, R.

1979-10-15

Catalysts resembling reforming catalysts were prepared to contain finely dispersed 0.75% Pt, 0.7% Re, or 0.35% Pt plus 0.1-2% Re on chlorided ..gamma..-alumina. The catalysts were dried in an oxidizing atmosphere and studied by temperature-programed reduction. Up to a Re/Pt ratio of 0.6:1 the metals were completely reduced in hydrogen below 255/sup 0/C, i.e., the platinum catalyzed rhenium reduction. A small amount of added water (< 50 ppm) also promoted rhenium reduction. Segregation of the metals occurred in oxygen above 200/sup 0/C, but at 100/sup 0/C, the rate of segregation was slow. These results suggested that under reforming conditions, Pt-Remore » catalysts are completely reduced bimetallic clusters. The mechanisms of reduction, cluster formation, and oxidative segregation are discussed.« less

Segregation of biomedical waste in an South Indian tertiary care hospital.

PubMed

Sengodan, Vetrivel Chezian

2014-07-01

Hospital wastes pose significant public health hazard if not properly managed. Hence, it is necessary to develop and adopt optimal waste management systems in the hospitals. Biomedical waste generated in Coimbatore Medical College Hospital was color coded (blue, yellow, and red) and the data was analyzed retrospectively on a daily basis for 3 years (January 2010-December 2012). Effective segregation protocols significantly reduced biomedical waste generated from 2011 to 2012. While biomedical waste of red category was significantly higher (>50%), the category yellow was the least. Per unit (per bed per day) total biomedical waste generated was 68.5, 68.8, and 61.3 grams in 2010, 2011, and 2012, respectively. Segregation of biomedical waste at the source of generation is the first and essential step in biomedical waste management. Continuous training, fixing the responsibility on the nursing persons, and constant supervision are the key criteria's in implementing biomedical waste segregation process, which can significantly reduce per unit biomedical waste generated. We highly recommend all hospitals to adopt our protocol and effectively implement them to reduce generation of biomedical waste.

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.

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

25 CFR 542.16 - What are the minimum internal control standards for information technology?

Code of Federal Regulations, 2011 CFR

2011-04-01

... information technology? 542.16 Section 542.16 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE... standards for information technology? Link to an amendment published at 73 FR 60498, Oct. 10, 2008. This... adequately segregated and monitored to prevent error in general information technology procedures to go...

25 CFR 542.16 - What are the minimum internal control standards for information technology?

Code of Federal Regulations, 2010 CFR

2010-04-01

... information technology? 542.16 Section 542.16 Indians NATIONAL INDIAN GAMING COMMISSION, DEPARTMENT OF THE... standards for information technology? Link to an amendment published at 73 FR 60498, Oct. 10, 2008. This... adequately segregated and monitored to prevent error in general information technology procedures to go...

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.

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.

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

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

Segregation of biomedical waste in an South Indian tertiary care hospital

PubMed Central

Sengodan, Vetrivel Chezian

2014-01-01

Introduction: Hospital wastes pose significant public health hazard if not properly managed. Hence, it is necessary to develop and adopt optimal waste management systems in the hospitals. Material and method: Biomedical waste generated in Coimbatore Medical College Hospital was color coded (blue, yellow, and red) and the data was analyzed retrospectively on a daily basis for 3 years (January 2010-December 2012). Results: Effective segregation protocols significantly reduced biomedical waste generated from 2011 to 2012. While biomedical waste of red category was significantly higher (>50%), the category yellow was the least. Per unit (per bed per day) total biomedical waste generated was 68.5, 68.8, and 61.3 grams in 2010, 2011, and 2012, respectively. Discussion: Segregation of biomedical waste at the source of generation is the first and essential step in biomedical waste management. Continuous training, fixing the responsibility on the nursing persons, and constant supervision are the key criteria's in implementing biomedical waste segregation process, which can significantly reduce per unit biomedical waste generated. Conclusion: We highly recommend all hospitals to adopt our protocol and effectively implement them to reduce generation of biomedical waste. PMID:25097419

Detection of component segregation in granules manufactured by high shear granulation with over-granulation conditions using near-infrared chemical imaging.

PubMed

Koide, Tatsuo; Nagato, Takuya; Kanou, Yoshiyuki; Matsui, Kou; Natsuyama, Susumu; Kawanishi, Toru; Hiyama, Yukio

2013-01-30

The objective of this study was to evaluate the high shear granulation process using near-infrared (NIR) chemical imaging technique and to make the findings available for pharmaceutical development. We prepared granules and tablets made under appropriate- and over-granulation conditions with high shear granulation and observed these granules and tablets using NIR chemical imaging system. We found an interesting phenomenon: lactose agglomeration and segregation of ingredients occurred in experimental tablets when over-granulation conditions, including greater impeller rotation speeds and longer granulation times, were employed. Granules prepared using over-granulation conditions were larger and had progressed to the consolidation stage; segregation between ethenzamide and lactose occurred within larger granules. The segregation observed here is not detectable using conventional analytical technologies such as high pressure liquid chromatography (HPLC) because the content of the granules remained uniform despite the segregation. Therefore, granule visualization using NIR chemical imaging is an effective method for investigating and evaluating the granulation process. Copyright © 2012 Elsevier B.V. All rights reserved.

The mismatch negativity as a measure of auditory stream segregation in a simulated "cocktail-party" scenario: effect of age.

PubMed

Getzmann, Stephan; Näätänen, Risto

2015-11-01

With age the ability to understand speech in multitalker environments usually deteriorates. The central auditory system has to perceptually segregate and group the acoustic input into sequences of distinct auditory objects. The present study used electrophysiological measures to study effects of age on auditory stream segregation in a multitalker scenario. Younger and older adults were presented with streams of short speech stimuli. When a single target stream was presented, the occurrence of a rare (deviant) syllable among a frequent (standard) syllable elicited the mismatch negativity (MMN), an electrophysiological correlate of automatic deviance detection. The presence of a second, concurrent stream consisting of the deviant syllable of the target stream reduced the MMN amplitude, especially when located nearby the target stream. The decrease in MMN amplitude indicates that the rare syllable of the target stream was less perceived as deviant, suggesting reduced stream segregation with decreasing stream distance. Moreover, the presence of a concurrent stream increased the MMN peak latency of the older group but not that of the younger group. The results provide neurophysiological evidence for the effects of concurrent speech on auditory processing in older adults, suggesting that older adults need more time for stream segregation in the presence of concurrent speech. Copyright © 2015 Elsevier Inc. All rights reserved.

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.

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

Screening of the Filamin C Gene in a Large Cohort of Hypertrophic Cardiomyopathy Patients.

PubMed

Gómez, Juan; Lorca, Rebeca; Reguero, Julian R; Morís, César; Martín, María; Tranche, Salvador; Alonso, Belén; Iglesias, Sara; Alvarez, Victoria; Díaz-Molina, Beatriz; Avanzas, Pablo; Coto, Eliecer

2017-04-01

Recent exome sequencing studies identified filamin C ( FLNC ) as a candidate gene for hypertrophic cardiomyopathy (HCM). Our aim was to determine the rate of FLNC candidate variants in a large cohort of HCM patients who were also sequenced for the main sarcomere genes. A total of 448 HCM patients were next generation-sequenced (semiconductor chip technology) for the MYH7, MYBPC3 , TNNT2 , TNNI3 , ACTC1 , TNNC1 , MYL2 , MYL3 , TPM1 , and FLNC genes. We also sequenced 450 healthy controls from the same population. Based on the reported population frequencies, bioinformatic criteria, and familial segregation, we identified 20 FLNC candidate variants (13 new; 1 nonsense; and 19 missense) in 22 patients. Compared with the patients, only 1 of the control's missense variants was nonreported ( P =0.007; Fisher exact probability test). Based on the familial segregation and the reported functional studies, 6 of the candidate variants (in 7 patients) were finally classified as likely pathogenic, 10 as variants of uncertain significance, and 4 as likely benign. We provide a compelling evidence of the involvement of FLNC in the development of HCM. Most of the FLNC variants were associated with mild forms of HCM and a reduced penetrance, with few affected in the families to confirm the segregation. Our work, together with others who found FLNC variants among patients with dilated and restrictive cardiomyopathies, pointed to this gene as an important cause of structural cardiomyopathies. © 2017 American Heart Association, Inc.

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

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.

NASA Astrophysics Data System (ADS)

McHugh, K. M.; Key, J. F.

1994-06-01

Spray forming is a near- net- shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or pattern to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing, often while substantially improving product quality. Spray forming is applicable to a wide range of metals and nonmetals and offers property improvements resulting from rapid solidification (e.g., refined microstructures, extended solid solubilities, and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray forming technology for producing near- net- shape solids and coatings of a variety of metals, polymers, and composite materials using de Laval nozzles. This article briefly describes the atomization behavior of liquid metals in linear de Laval nozzles and illustrates the versatility of the process by summarizing results from two spray forming programs. In one program, low-carbon steel strip >0.75 mm thick was produced; in the other, polymer membranes ˜5 μm thick were spray formed.

Investigation of CO2 release pressures in pipeline cracks

NASA Astrophysics Data System (ADS)

Gorenz, Paul; Herzog, Nicoleta; Egbers, Christoph

2013-04-01

The CCS (Carbon Capture and Storage) technology can prevent or reduce the emissions of carbon dioxide. The main idea of this technology is the segregation and collection of CO2 from facilities with a high emission of that greenhouse gas, i.e. power plants which burn fossil fuels. To segregate CO2 from the exhaust gas the power plant must be upgraded. Up to now there are three possible procedures to segregate the carbon dioxide with different advantages and disadvantages. After segregation the carbon dioxide will be transported by pipeline to a subsurface storage location. As CO2 is at normal conditions (1013,25 Pa; 20 °C) in a gaseous phase state it must be set under high pressure to enter denser phase states to make a more efficient pipeline transport possible. Normally the carbon dioxide is set into the liquid or supercritical phase state by compressor stations which compress the gas up to 15 MPa. The pressure drop makes booster stations along the pipeline necessary which keep the CO2 in a dens phase state. Depending on the compression pressure CO2 can be transported over 300km without any booster station. The goal of this work is the investigation of release pressures in pipeline cracks. The high pressurised pipeline system consists of different parts with different failure probabilities. In most cases corrosion or obsolescence is the reason for pipeline damages. In case of a crack CO2 will escape from the pipeline and disperse into the atmosphere. Due to its nature CO2 can remain unattended for a long time. There are some studies of the CO2 dispersion process, e.g. Mazzoldi et al. (2007, 2008 and 2011) and Wang et al. (2008), but with different assumptions concerning the pipeline release pressures. To give an idea of realistic release pressures investigations with the CFD tool OpenFOAM were carried out and are presented within this work. To cover such a scenario with an accidental release of carbon dioxide a pipeline section with different diameters and leakage release holes were modelled. This pipeline section is 10m long with the leakage hole in the middle. Additionally a small environment subdomain is simulated around the crack. For computation a multiphase solver was utilised. In a first step incompressible and isothermal fluids with no phase change were assumed.

Implications of Income-Based School Assignment Policies for Racial School Segregation

ERIC Educational Resources Information Center

Reardon, Sean F.; Yun, John T.; Kurlaender, Michal

2006-01-01

A number of public school districts in the United States have adopted income-based integration policies--policies that use measures of family income or socioeconomic status--in determining school assignment. Some scholars and policymakers contend that such policies will also reduce racial segregation. In this article this assumption is explored by…

Gender Segregation of Adolescent Science Career Plans in 50 Countries

ERIC Educational Resources Information Center

Sikora, Joanna; Pokropek, Artur

2012-01-01

Using data from the Program for International Student Assessment 2006 surveys for 50 countries, this paper explores gender segregation of adolescent science career plans. We ask whether, in different cultures, bridging the male-female gap in science self-concept could reduce gender disparities in students' career preferences. Bringing together the…

Investigation of Artificial Forced Cooling in the Bridgman Crystal Growth of Cadmium Zinc Telluride

NASA Astrophysics Data System (ADS)

Liu, Juncheng; Li, Jiao; Zhang, Guodong; Li, Changxing; Lennon, Craig; Sivananthan, Siva

2007-08-01

The effects of artificial forced cooling on the solid liquid interface and on solute segregation were investigated by modeling the vertical Bridgman method for the single-crystal growth of CdZnTe, taking into consideration effects such as increasing the axial outward heat flux from the crucible bottom, the radial outward heat flux from the crucible wall, and the carbon film thickness on the crucible inner wall. Axial artificially forced cooling noticeably increases convection and the temperature gradient in the melt next to the solid liquid interface, and substantially reduces interface concavity at the initial solidification stage. Interface concavity increases a little when the solidification proceeds further, however. Axial artificially forced cooling reduces radial solute segregation of the initial segment of the grown crystal and slightly increases the solute iso-concentration segment. Radial artificially forced cooling enhances melt convection substantially, affects solid liquid interface concavity only slightly, and hardly affects solute segregation in the grown crystal. Doubling the carbon film thickness weakens convection of the melt in front of the interface, substantially increases interface concavity, and hardly affects solute segregation in the grown crystal.

GTSE1 tunes microtubule stability for chromosome alignment and segregation by inhibiting the microtubule depolymerase MCAK

PubMed Central

Bendre, Shweta; Hall, Conrad; Lin, Yu-Chih

2016-01-01

The dynamic regulation of microtubules (MTs) during mitosis is critical for accurate chromosome segregation and genome stability. Cancer cell lines with hyperstabilized kinetochore MTs have increased segregation errors and elevated chromosomal instability (CIN), but the genetic defects responsible remain largely unknown. The MT depolymerase MCAK (mitotic centromere-associated kinesin) can influence CIN through its impact on MT stability, but how its potent activity is controlled in cells remains unclear. In this study, we show that GTSE1, a protein found overexpressed in aneuploid cancer cell lines and tumors, regulates MT stability during mitosis by inhibiting MCAK MT depolymerase activity. Cells lacking GTSE1 have defects in chromosome alignment and spindle positioning as a result of MT instability caused by excess MCAK activity. Reducing GTSE1 levels in CIN cancer cell lines reduces chromosome missegregation defects, whereas artificially inducing GTSE1 levels in chromosomally stable cells elevates chromosome missegregation and CIN. Thus, GTSE1 inhibition of MCAK activity regulates the balance of MT stability that determines the fidelity of chromosome alignment, segregation, and chromosomal stability. PMID:27881713

Application of CRISPR technology in genome editing in agriculture -swine

USDA-ARS?s Scientific Manuscript database

Decades of selective breeding in agricultural species has led to the derivation of stronger and fitter animals with improved production traits. However, often co-segregating with beneficial traits are less desirable traits. With the plethora of genome data and annotation, has come the technology t...

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.

A system dynamics approach for healthcare waste management: a case study in Istanbul Metropolitan City, Turkey.

PubMed

Ciplak, Nesli; Barton, John R

2012-06-01

Healthcare waste consists of various types of waste materials generated at hospitals, medical research centres, clinics and laboratories. Although 75-90% of this waste is classified as 'domestic' in nature, 20-25% is deemed to be hazardous, which if not disposed of appropriately, poses a risk to healthcare workers, patients, the environment and even the whole community. As long as healthcare waste is mixed with municipal waste and not segregated prior to disposal, costs will increase substantially. In this study, healthcare waste increases along with the potential to decrease the amounts by implementing effective segregation at healthcare facilities are projected to 2040. Our long-term aim is to develop a system to support selection and planning of the future treatment capacity. Istanbul in Turkey was used as the case study area. In order to identify the factors affecting healthcare waste generation in Istanbul, observations were made and interviews conducted in Istanbul over a 3 month period. A system dynamics approach was adopted to build a healthcare waste management model using a software package, Vensim Ple Plus. Based on reported analysis, the non-hazardous municipal fraction co-disposed with healthcare waste is around 65%. Using the projected waste generation flows, reducing a municipal fraction to 30% has the potential to avoid some 8000 t year(-1) of healthcare waste by 2025 and almost 10 000 t year(-1) by 2035. Furthermore, if segregation practices ensured healthcare waste requiring incineration was also selectively managed, 77% of healthcare waste could be diverted to alternative treatment technologies. As the throughput capacity of the only existing healthcare waste treatment facility in Istanbul, Kemerburgaz Incinerator, has already been exceeded, it is evident that improved management could not only reduce overall flows and costs but also permit alternative and cheaper treatment systems (e.g. autoclaving) to be adopted for the healthcare waste.

Sexual segregation in Roosevelt Elk: Cropping rates and aggression in mixed sex groups

USGS Publications Warehouse

Weckerly, Floyd F.; Ricca, Mark A.; Meyer, Katherin P.

2001-01-01

Few studies of sexual segregation in ruminants have tested widely invoked mechanisms of segregation in mixed-sex groups. In a sexually segregated population of Roosevelt elk (Cervus elaphus roosevelti), we examined if adult males had reduced intake of forage when in mixed-sex groups and if intersexual differences in aggression caused females to avoid males. Based on a mechanistic model of forage intake, animals with lower instantaneous feed intake should have higher cropping rates. Focal animal sampling indicated that adult males and females in summer and winter had similar cropping rates in mixed-sex groups, whereas males in male-only groups had lower rates of cropping than males in mixed-sex groups. Outside the mating season, males in male groups spent proportionally less time ≤1 body length of congenders than females in female groups, and the rate of aggression ≤1 body length was higher for males. Female–female aggression was higher in mixed-sex groups that contained more males than the median proportion of males in mixed-sex groups. Female and mixed-sex groups walked away when groups of males numbering >6 were ≤50 m but did not walk away when male groups ≤50 m had ≤5 individuals. Sexual segregation was associated with behaviors of sexes in mixed-sex groups: reduced intake of forage by males and increased female–female aggression with more males.

Psycho-Social Determinants of Gender Prejudice in Science, Technology, Engineering and Mathematics

ERIC Educational Resources Information Center

Nnachi, N. O.; Okpube, M. N.

2015-01-01

This work focused on the "Psycho-social Determinants of Gender Prejudice in Science, Technology, Engineering and Mathematics (STEM)". The females were found to be underrepresented in STEM fields. The under-representation results from gender stereotype, differences in spatial skills, hierarchical and territorial segregations and…

TEC Center: Linking Technology, Education and Cultural Diversity

ERIC Educational Resources Information Center

Hoter, Elaine; Shonfeld, Miri; Asmaa, N. Ganayem

2012-01-01

To many people, "Israel" is perceived as a "high-tech" nation, but in the same breath, as a "nation in conflict." So why not apply Israel's technological advantage to battle the multicultural conflict within? In this article, we will review the multicultural segregation in Israel, the traditional attempts to bring…

Surface Segregation in Multicomponent Systems: Modeling of Surface Alloys and Alloy Surfaces

NASA Technical Reports Server (NTRS)

Bozzolo, Guillermo; Ferrante, John; Noebe, Ronald D.; Good, Brian; Honecy, Frank S.; Abel, Phillip

1999-01-01

The study of surface segregation, although of great technological importance, has been largely restricted to experimental work due to limitations associated with theoretical methods. However, recent improvements in both first-particle and semi-empirical methods are opening, the doors to an array of new possibilities for surface scientists. We apply one of these techniques, the Bozzolo, Ferrante and Smith (BFS) method for alloys, which is particularly suitable for complex systems, to several aspects of the computational modeling of surfaces and segregation, including alloy surface segregation, structure and composition of alloy surfaces, and the formation of surface alloys. We conclude with the study of complex NiAl-based binary, ternary and quaternary thin films (with Ti, Cr and Cu additions to NiAl). Differences and similarities between bulk and surface compositions are discussed, illustrated by the results of Monte Carlo simulations. For some binary and ternary cases, the theoretical predictions are compared to experimental results, highlighting the accuracy and value of this developing theoretical tool.

Evaporation-Triggered Segregation of Sessile Binary Droplets.

PubMed

Li, Yaxing; Lv, Pengyu; Diddens, Christian; Tan, Huanshu; Wijshoff, Herman; Versluis, Michel; Lohse, Detlef

2018-06-01

Droplet evaporation of multicomponent droplets is essential for various physiochemical applications, e.g., in inkjet printing, spray cooling, and microfabrication. In this work, we observe and study the phase segregation of an evaporating sessile binary droplet, consisting of a miscible mixture of water and a surfactantlike liquid (1,2-hexanediol). The phase segregation (i.e., demixing) leads to a reduced water evaporation rate of the droplet, and eventually the evaporation process ceases due to shielding of the water by the nonvolatile 1,2-hexanediol. Visualizations of the flow field by particle image velocimetry and numerical simulations reveal that the timescale of water evaporation at the droplet rim is faster than that of the Marangoni flow, which originates from the surface tension difference between water and 1,2-hexanediol, eventually leading to segregation.

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

The pedogeochemical segregation a few horizons in soils from glass houses

NASA Astrophysics Data System (ADS)

Bulgariu, Dumitru; Rusu, Constantin; Filipov, Feodor; Buzgar, Nicolae; Bulgariu, Laura

2010-05-01

Our studies have focused the apparition and manifestation conditions of pedogeochemical segregation phenomena in case of soils from Copou - Iaşi, Bacău and Bârlad (Romania) glass house, and the effects of this on the pedogeochemical and agrochemical characteristics of soils from glass houses cultivated with vegetables. The utilization of intensive cultivation technologies of vegetables in glass houses determined the degradation of morphological, physical and chemical characteristics of soils, by rapid evolution of salted processes (salinization and / or sodization), compaction, carbonatation, eluviation-illuviation, frangipane formation, stagnogleization, gleization etc. Under these conditions, at depth of 30-40 cm is formed a compact and impenetrable horizon - Ahok(x) horizon. In function of exploitation conditions and by the chemical-mineralogical characteristics of soils from glasshouses, the Ahok horizons can have frangipane properties, expressed more or less. These horizons determined a geochemical segregation of soils from glass houses: (i) superior horizons, above Ahok(x) horizon evolve in weak oxidative conditions, weak alkaline pH, higher salinity, humidity and temperature; (ii) inferior horizons, below Ahok(x) horizon evolve in weak reducing conditions weak acid pH, lower salinity, humidity and temperature. Concomitant with the development of Ahok(x) horizons, the rapid degradation of the properties of soils from glasshouses is observed. The aspects about the formation of frangipane horizon in soils from glasshouses are not yet sufficiently know. Whatever of the formation processes, the frangipane horizons determined a sever segregation in pedogeochemical evolution of soils from glass houses, with very important consequences on the agrochemical quality of these soils. The segregation effects are manifested in the differential dynamics of pedogeochemical processes from superior horizons (situated above the segregation horizon), in comparison with the inferior horizons (situated below the segregation horizon), and in global evolution of degradation processes of soils from glasshouses. The results obtained by as have shown that together by mobile forms of Si, Al and Fe, at the formation of segregation horizons (frangipane), an important role has the phosphorus (organic. in special) and the organic-mineral complexes, respectively. The experimental results indicate a strong accumulation tendency, at the level of pedogeochemical segregation horizons - Ahok(x) horizons, of fin grain-size fractions and of amorphous forms of mineral components. Also, was observed that in the composition of soil aggregates from frangipane horizon, and important weight have the smectites, amorphous iron oxides and oxy-hydroxides, amorphous silica and organic matter. The particularity of pedogeochemical segregation horizon (frangipane) from Copou-Iaşi glass house is given by the relatively high contents of: (i) phosphorus - organic, in special, as inositol-phosphoric esters; (ii) fulvic acids; (iii) organic-mineral complexes - with special composition and structure, and (iv) poly-metha-phosphate associated with aluminosilicated gel - from chemical point of view has the characteristics of a pseudo-solid solution by (SiO2)x(Al2O3)y(PO4)z type, where x / z = (10-16) / 1, and y / z = (3-5) / 1); this appear as nodular depositions ( = 3-5 mm) covered with thin iron-carbonated crust. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51-045/07).

The Influence of the Cold War on the Racial Desegregation of American Schools

ERIC Educational Resources Information Center

Watras, Joseph

2013-01-01

With the rise of the Cold War, federal officials in the United States sought to end the racial segregation that the U.S. Supreme Court had accepted in the 1896 decision of "Plessy v. Ferguson." Although the reforms began with changes in the armed services, they moved to reduce racial segregation in schools. Many forces brought about the…

Natural experiment examining the longitudinal association between change in residential segregation and youth cardiovascular health across race/ethnicity and gender in the USA.

PubMed

D'Agostino, Emily M; Patel, Hersila H; Ahmed, Zafar; Hansen, Eric; Mathew, M Sunil; Nardi, Maria I; Messiah, Sarah E

2018-05-10

Identifying how racial/ethnic residential segregation and mobility may impact health can guide innovative strategies for reducing youth disparities. This natural experiment examined the association between change in residential segregation and cardiovascular health outcomes across race/ethnicity and gender for youth (n=2250, mean age 9.1 years, 54% male; 51% Hispanic, 49% non-Hispanic black (NHB); 49% high area poverty) attending a multisite park-based afterschool fitness programme in Florida, USA. Two-level generalised linear mixed models with random intercepts for park effects were fit to test the change in segregation-cardiovascular health association over two school years. After covariate adjustment (individual-level gender, race/ethnicity, age, time and park-area poverty), greater improvements in cardiovascular health including body mass index percentile, sum of skinfold thicknesses, systolic/diastolic blood pressure percentiles and 400 m run time were found for youth who attended the program in a less segregated area compared with their home area (p<0.05 for all outcomes). NHB girls showed the greatest cardiovascular health improvements. Specifically, compared with the reference group (no change in segregation), skinfold thicknesses and systolic blood pressure percentiles decreased 17% (incidence rate ratio (IRR) 95% CI 0.81 to 0.86) and 16% (IRR 95% CI 0.82 to 0.87), respectively, versus 1% increase for both outcomes (IRR 95% CI 0.98 to 1.05) and (IRR 95% CI 0.98 to 1.05), respectively, for movement to less versus more segregated areas. In light of a continually expanding youth obesity epidemic, the global effort to reduce health inequities may be supported through Parks and Recreation Departments given potential to expand geographic mobility for low resource subgroups. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

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

Male reproductive strategy explains spatiotemporal segregation in brown bears

PubMed Central

Steyaert, Sam MJG; Kindberg, Jonas; Swenson, Jon E; Zedrosser, Andreas

2013-01-01

1. Spatiotemporal segregation is often explained by the risk for offspring predation or by differences in physiology, predation risk vulnerability or competitive abilities related to size dimorphism. 2. Most large carnivores are size dimorphic and offspring predation is often intraspecific and related to nonparental infanticide (NPI). NPI can be a foraging strategy, a strategy to reduce competition, or a male reproductive strategy. Spatiotemporal segregation is widespread among large carnivores, but its nature remains poorly understood. 3. We evaluated three hypotheses to explain spatiotemporal segregation in the brown bear, a size-dimorphic large carnivore in which NPI is common; the ‘NPI – foraging/competition hypothesis', i.e. NPI as a foraging strategy or a strategy to reduce competition, the ‘NPI – sexual selection hypothesis’, i.e. infanticide as a male reproductive strategy and the ‘body size hypothesis’, i.e. body-size-related differences in physiology, predation risk vulnerability or competitive ability causes spatiotemporal segregation. To test these hypotheses, we quantified spatiotemporal segregation among adult males, lone adult females and females with cubs-of-the-year, based on GPS-relocation data (2006–2010) and resource selection functions in a Scandinavian population. 4. We found that spatiotemporal segregation was strongest between females with cubs-of-the-year and adult males during the mating season. During the mating season, females with cubs-of-the-year selected their resources, in contrast to adult males, in less rugged landscapes in relative close proximity to certain human-related variables, and in more open habitat types. After the mating season, females with cubs-of-the-year markedly shifted their resource selection towards a pattern more similar to that of their conspecifics. No strong spatiotemporal segregation was apparent between females with cubs-of-the-year and conspecifics during the mating and the postmating season. 5. The ‘NPI – sexual selection hypothesis’ best explained spatiotemporal segregation in our study system. We suggest that females with cubs-of-the-year alter their resource selection to avoid infanticidal males. In species exhibiting NPI as a male reproductive strategy, female avoidance of infanticidal males is probably more common than observed or reported, and may come with a fitness cost if females trade safety for optimal resources. PMID:23461483

Crossword: A Fully Automated Algorithm for the Segmentation and Quality Control of Protein Microarray Images

PubMed Central

2015-01-01

Biological assays formatted as microarrays have become a critical tool for the generation of the comprehensive data sets required for systems-level understanding of biological processes. Manual annotation of data extracted from images of microarrays, however, remains a significant bottleneck, particularly for protein microarrays due to the sensitivity of this technology to weak artifact signal. In order to automate the extraction and curation of data from protein microarrays, we describe an algorithm called Crossword that logically combines information from multiple approaches to fully automate microarray segmentation. Automated artifact removal is also accomplished by segregating structured pixels from the background noise using iterative clustering and pixel connectivity. Correlation of the location of structured pixels across image channels is used to identify and remove artifact pixels from the image prior to data extraction. This component improves the accuracy of data sets while reducing the requirement for time-consuming visual inspection of the data. Crossword enables a fully automated protocol that is robust to significant spatial and intensity aberrations. Overall, the average amount of user intervention is reduced by an order of magnitude and the data quality is increased through artifact removal and reduced user variability. The increase in throughput should aid the further implementation of microarray technologies in clinical studies. PMID:24417579

Improving the Thermodynamic Stability of Aluminate Spinel Nanoparticles with Rare Earths

DOE PAGES

Hasan, M. M.; Dey, Sanchita; Nafsin, Nazia; ...

2016-06-29

Surface energy is a key parameter to understand and predict the stability of catalysts. In this work, the surface energy of MgAl 2O 4, an important base material for catalyst support, was reduced by using dopants prone to form surface excess (surface segregation): Y 3+, Gd 3+, and La 3+. The energy reduction was predicted by atomistic simulations of spinel surfaces and experimentally demonstrated by using microcalorimetry. The surface energy of undoped MgAl 2O 4 was directly measured as 1.65 ± 0.04 J/m 2 and was reduced by adding 2 mol % of the dopants to 1.55 ± 0.04 J/mmore » 2 for Y-doping, 1.45 ± 0.05 J/m 2 for Gd-doping, and 1.26 ± 0.06 J/m 2 for La-doping. Atomistic simulations are qualitatively consistent with the experiments, reinforcing the link between the role of dopants in stabilizing the surface and the energy of segregation. Surface segregation was experimentally assessed using electron energy loss spectroscopy mapping in a scanning transmission electron microscopy image. Finally, the reduced energy resulted in coarsening inhibition for the doped samples and, hence, systematically smaller particle sizes (larger surface areas), meaning increased stability for catalytic applications. Moreover, both experiment and modeling reveal preferential dopant segregation to specific surfaces, which leads to the preponderance of {111} surface planes and suggests a strategy to enhance the area of desired surfaces in nanoparticles for better catalyst support activity.« less

INEL Spray-forming Research

NASA Technical Reports Server (NTRS)

Mchugh, Kevin M.; Key, James F.

1993-01-01

Spray forming is a near-net-shape fabrication technology in which a spray of finely atomized liquid droplets is deposited onto a suitably shaped substrate or mold to produce a coherent solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g., refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. Researchers at the Idaho National Engineering Laboratory (INEL) are developing spray-forming technology for producing near-net-shape solids and coatings of a variety of metals, polymers, and composite materials. Results from several spray forming programs are presented to illustrate the range of capabilities of the technique as well as the accompanying technical and economic benefits. Low-carbon steel strip greater than 0.75 mm thick and polymer membranes for gas/gas and liquid/liquid separations that were spray formed are discussed; recent advances in spray forming molds, dies, and other tooling using low-melting-point metals are described.

Audio Watermark Embedding Technique Applying Auditory Stream Segregation: "G-encoder Mark" Able to Be Extracted by Mobile Phone

NASA Astrophysics Data System (ADS)

Modegi, Toshio

We are developing audio watermarking techniques which enable extraction of embedded data by cell phones. For that we have to embed data onto frequency ranges, where our auditory response is prominent, therefore data embedding will cause much auditory noises. Previously we have proposed applying a two-channel stereo play-back feature, where noises generated by a data embedded left-channel signal will be reduced by the other right-channel signal. However, this proposal has practical problems of restricting extracting terminal location. In this paper, we propose synthesizing the noise reducing right-channel signal with the left-signal and reduces noises completely by generating an auditory stream segregation phenomenon to users. This newly proposed makes the noise reducing right-channel signal unnecessary and supports monaural play-back operations. Moreover, we propose a wide-band embedding method causing dual auditory stream segregation phenomena, which enables data embedding on whole public phone frequency ranges and stable extractions with 3-G mobile phones. From these proposals, extraction precisions become higher than those by the previously proposed method whereas the quality damages of embedded signals become smaller. In this paper we present an abstract of our newly proposed method and experimental results comparing with those by the previously proposed method.

Treatment of segregated black/grey domestic wastewater using constructed wetlands in the Mediterranean basin: the zer0-m experience.

PubMed

Masi, F; El Hamouri, B; Abdel Shafi, H; Baban, A; Ghrabi, A; Regelsberger, M

2010-01-01

Concerns about water shortage and pollution have received increased attention over the past few years, especially in developing countries with warm climate. In order to help local water management in these countries, the Euro-Mediterranean Regional Programme (MEDA) has financed the Zer0-m project (E-mail: www.zer0-m.org). As a part of this project, several constructed wetland (CW) pilot systems with different pre-treatments have been implemented in four Technological Demonstration Centres in Egypt, Morocco, Tunisia and Turkey. The aim of this research was to establish appropriate designs for treatment of segregated domestic black (BW) and grey water (GW). We tested several different multistage CW configurations, consisting of horizontal and vertical subsurface flow CW for secondary treatment and free water systems as tertiary stage. CW removal efficiencies of TSS, COD, BOD(5), N-NH(4)(+), N-NO(3)(-), N(tot), total coliforms (TC) were evaluated for each of the implemented systems. The results from this study demonstrate the potential of CWs as a suitable technology for treating segregated domestic wastewater. A very efficient COD reduction (up to 98%) and nitrification (92-99%) was achieved for BW and GW in all systems. CW effluent concentrations were below 15 mg/L for BOD(5), 1 mg/L for N-NO(3)(-) and 0.5 mg/L for N-NH(4)(+) together with acceptable TC counts. Based on these results, we suggest adopting the design parameters used in this study for the treatment of segregated wastewater in the Mediterranean area.

Using Zebra-speech to study sequential and simultaneous speech segregation in a cochlear-implant simulation.

PubMed

Gaudrain, Etienne; Carlyon, Robert P

2013-01-01

Previous studies have suggested that cochlear implant users may have particular difficulties exploiting opportunities to glimpse clear segments of a target speech signal in the presence of a fluctuating masker. Although it has been proposed that this difficulty is associated with a deficit in linking the glimpsed segments across time, the details of this mechanism are yet to be explained. The present study introduces a method called Zebra-speech developed to investigate the relative contribution of simultaneous and sequential segregation mechanisms in concurrent speech perception, using a noise-band vocoder to simulate cochlear implants. One experiment showed that the saliency of the difference between the target and the masker is a key factor for Zebra-speech perception, as it is for sequential segregation. Furthermore, forward masking played little or no role, confirming that intelligibility was not limited by energetic masking but by across-time linkage abilities. In another experiment, a binaural cue was used to distinguish the target and the masker. It showed that the relative contribution of simultaneous and sequential segregation depended on the spectral resolution, with listeners relying more on sequential segregation when the spectral resolution was reduced. The potential of Zebra-speech as a segregation enhancement strategy for cochlear implants is discussed.

Using Zebra-speech to study sequential and simultaneous speech segregation in a cochlear-implant simulation

PubMed Central

Gaudrain, Etienne; Carlyon, Robert P.

2013-01-01

Previous studies have suggested that cochlear implant users may have particular difficulties exploiting opportunities to glimpse clear segments of a target speech signal in the presence of a fluctuating masker. Although it has been proposed that this difficulty is associated with a deficit in linking the glimpsed segments across time, the details of this mechanism are yet to be explained. The present study introduces a method called Zebra-speech developed to investigate the relative contribution of simultaneous and sequential segregation mechanisms in concurrent speech perception, using a noise-band vocoder to simulate cochlear implants. One experiment showed that the saliency of the difference between the target and the masker is a key factor for Zebra-speech perception, as it is for sequential segregation. Furthermore, forward masking played little or no role, confirming that intelligibility was not limited by energetic masking but by across-time linkage abilities. In another experiment, a binaural cue was used to distinguish target and masker. It showed that the relative contribution of simultaneous and sequential segregation depended on the spectral resolution, with listeners relying more on sequential segregation when the spectral resolution was reduced. The potential of Zebra-speech as a segregation enhancement strategy for cochlear implants is discussed. PMID:23297922

Despotism and risk of infanticide influence grizzly bear den-site selection.

PubMed

Libal, Nathan S; Belant, Jerrold L; Leopold, Bruce D; Wang, Guiming; Owen, Patricia A

2011-01-01

Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.

Impact of change in neighborhood racial/ethnic segregation on cardiovascular health in minority youth attending a park-based afterschool program.

PubMed

D'Agostino, Emily M; Patel, Hersila H; Ahmed, Zafar; Hansen, Eric; Sunil Mathew, M; Nardi, Maria I; Messiah, Sarah E

2018-05-01

Research on the mechanistic factors associating racial/ethnic residential segregation with health is needed to identify effective points of intervention to ultimately reduce health disparities in youth. We examined the association of changes in racial/ethnic segregation and cardiovascular health outcomes including body mass index percentile, sum of skinfold thicknesses, systolic and diastolic blood pressure percentile, and 400 m run time in non-Hispanic Black (NHB) and Hispanic youth (n = 2,250, mean age 9.1 years, 54% male; 51% Hispanic, 49% NHB; 49% high area poverty; 25% obese) attending Fit2Play™, a multisite park-based afterschool program in Miami, Florida, USA. A series of crude and adjusted two-level longitudinal generalized linear mixed models with random intercepts for park effects were fit to assess the association of change in segregation between home and program/park site and cardiovascular health outcomes for youth who participated for up to two school years in Fit2Play™. After adjusting for individual-level factors (sex, age, time, and park-area poverty) models showed significantly greater improvements in cardiovascular health if youth attended Fit2Play™ in an area less segregated than their home area (p < 0.05 for all outcomes) except 400 m run time and diastolic blood pressure percentile in Hispanics (p<.001 and p = 0.11, respectively). Area poverty was not found to confound or significantly modify this association. These findings have implications for youth programming focused on reducing health disparities and improving cardiovascular outcomes in NHB and Hispanic youth, particularly in light of a continually expanding obesity epidemic in these groups. Parks and Recreation Departments have potential to expand geographic mobility for minorities, therein supporting the national effort to reduce health inequalities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Nanosegregated bimetallic oxide anode catalyst for proton exchange membrane electrolyzer

DOEpatents

Danilovic, Nemanja; Kang, Yijin; Markovic, Nenad; Stamenkovic, Vojislav; Myers, Deborah J.; Subbaraman, Ram

2016-08-23

A surface segregated bimetallic composition of the formula Ru.sub.1-xIr.sub.x wherein 0.1.ltoreq.x.ltoreq.0.75, wherein a surface of the material has an Ir concentration that is greater than an Ir concentration of the material as a whole is provided. The surface segregated material may be produced by a method including heating a bimetallic composition of the formula Ru.sub.1-xIr.sub.x, wherein 0.1.ltoreq.x.ltoreq.0.75, at a first temperature in a reducing environment, and heating the composition at a second temperature in an oxidizing environment. The surface segregated material may be utilized in electrochemical devices.

Childhood school segregation and later life sense of control and physical performance in the African American Health cohort.

PubMed

Wolinsky, Fredric D; Andresen, Elena M; Malmstrom, Theodore K; Miller, J Philip; Schootman, Mario; Miller, Douglas K

2012-09-27

The association between childhood school desegregation and later life sense of control and physical performance among African Americans is not clear. We hypothesized that childhood school desegregation adversely affected the sense of control of in later life, and that this reduced sense of control accounts in part for reduced physical performance. In-home follow-up assessments were completed in 2010 with 582 of the 58-74 year old men and women participating in the on-going African American Health cohort. We used these data to examine the relationship between (a) retrospective self-reports of attending segregated schools during one's 1st-to-12th grade education and one's current sense of control, as well as (b) the association between current sense of control and physical performance. Multiple linear regression analysis with propensity score re-weighting was used. Attending segregated schools for at least half of one's 1st-to-12th grade education was significantly associated with higher scores on the sense of control. Adjusting for all covariates and potential confounders, those receiving half or more of their 1st-to-12th grade education in segregated schools had sense of control scores that were .886 points higher (p ≤ .01; standardized effect size = .22). Sense of control scores were independently (all p < .01) associated with better systolic blood pressure, grip strength, peak expiratory flow, chair stands, balance tests, and the Short Portable Physical Battery even after adjusting for all covariates and potential confounders. Moreover, sense of control scores either partially or fully mediated the statistically significant beneficial associations between childhood school segregation and physical performance. Childhood school desegregation was adversely associated with the sense of control of African Americans in later life, and this reduced sense of control appears, in part, to account for their poorer physical performance. The etiologic mechanism through which childhood school segregation at the time that this cohort experienced it improved the sense of control in later life, which subsequently led to better physical performance, has not been identified. We suspect, however, that the pathway involves greater exposure to racial solidarity, same-race students as peer role models and same-race teachers and principals as authority role models, the reduced likelihood of exposure to race-based discrimination or antagonism during their formative early lives, and greater exposure to encouragement and support for academic and life success.

Childhood school segregation and later life sense of control and physical performance in the African American Health cohort

PubMed Central

2012-01-01

Background The association between childhood school desegregation and later life sense of control and physical performance among African Americans is not clear. We hypothesized that childhood school desegregation adversely affected the sense of control of in later life, and that this reduced sense of control accounts in part for reduced physical performance. Methods In-home follow-up assessments were completed in 2010 with 582 of the 58–74 year old men and women participating in the on-going African American Health cohort. We used these data to examine the relationship between (a) retrospective self-reports of attending segregated schools during one’s 1st-to-12th grade education and one’s current sense of control, as well as (b) the association between current sense of control and physical performance. Multiple linear regression analysis with propensity score re-weighting was used. Results Attending segregated schools for at least half of one’s 1st-to-12th grade education was significantly associated with higher scores on the sense of control. Adjusting for all covariates and potential confounders, those receiving half or more of their 1st-to-12th grade education in segregated schools had sense of control scores that were .886 points higher (p ≤ .01; standardized effect size = .22). Sense of control scores were independently (all p < .01) associated with better systolic blood pressure, grip strength, peak expiratory flow, chair stands, balance tests, and the Short Portable Physical Battery even after adjusting for all covariates and potential confounders. Moreover, sense of control scores either partially or fully mediated the statistically significant beneficial associations between childhood school segregation and physical performance. Conclusions Childhood school desegregation was adversely associated with the sense of control of African Americans in later life, and this reduced sense of control appears, in part, to account for their poorer physical performance. The etiologic mechanism through which childhood school segregation at the time that this cohort experienced it improved the sense of control in later life, which subsequently led to better physical performance, has not been identified. We suspect, however, that the pathway involves greater exposure to racial solidarity, same-race students as peer role models and same-race teachers and principals as authority role models, the reduced likelihood of exposure to race-based discrimination or antagonism during their formative early lives, and greater exposure to encouragement and support for academic and life success. PMID:23017218

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

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.

Black silicon significantly enhances phosphorus diffusion gettering.

PubMed

Pasanen, Toni P; Laine, Hannu S; Vähänissi, Ville; Schön, Jonas; Savin, Hele

2018-01-31

Black silicon (b-Si) is currently being adopted by several fields of technology, and its potential has already been demonstrated in various applications. We show here that the increased surface area of b-Si, which has generally been considered as a drawback e.g. in applications that require efficient surface passivation, can be used as an advantage: it enhances gettering of deleterious metal impurities. We demonstrate experimentally that interstitial iron concentration in intentionally contaminated silicon wafers reduces from 1.7 × 10 13  cm -3 to less than 10 10  cm -3 via b-Si gettering coupled with phosphorus diffusion from a POCl 3 source. Simultaneously, the minority carrier lifetime increases from less than 2 μs of a contaminated wafer to more than 1.5 ms. A series of different low temperature anneals suggests segregation into the phosphorus-doped layer to be the main gettering mechanism, a notion which paves the way of adopting these results into predictive process simulators. This conclusion is supported by simulations which show that the b-Si needles are entirely heavily-doped with phosphorus after a typical POCl 3 diffusion process, promoting iron segregation. Potential benefits of enhanced gettering by b-Si include the possibility to use lower quality silicon in high-efficiency photovoltaic devices.

Near-net-shape manufacturing: Spray-formed metal matrix composites and tooling

NASA Technical Reports Server (NTRS)

Mchugh, Kevin M.

1994-01-01

Spray forming is a materials processing technology in which a bulk liquid metal is converted to a spray of fine droplets and deposited onto a substrate or pattern to form a near-net-shape solid. The technology offers unique opportunities for simplifying materials processing without sacrificing, and oftentimes substantially improving, product quality. Spray forming can be performed with a wide range of metals and nonmetals, and offers property improvements resulting from rapid solidification (e.g. refined microstructures, extended solid solubilities and reduced segregation). Economic benefits result from process simplification and the elimination of unit operations. The Idaho National Engineering Laboratory is developing a unique spray-forming method, the Controlled Aspiration Process (CAP), to produce near-net-shape solids and coatings of metals, polymers, and composite materials. Results from two spray-accompanying technical and economic benefits. These programs involved spray forming aluminum strip reinforced with SiC particulate, and the production of tooling, such as injection molds and dies, using low-melting-point metals.

Bacterial chromosome organization and segregation

PubMed Central

Badrinarayanan, Anjana; Le, Tung BK; Laub, Michael T

2016-01-01

If fully stretched out, a typical bacterial chromosome would be nearly one millimeter long, or approximately 1000 times the length of a cell. Not only must cells massively compact their genetic material, but they must also organize their DNA in a manner that is compatible with a range of cellular processes, including DNA replication, DNA repair, homologous recombination, and horizontal gene transfer. Recent work, driven in part by technological advances, has begun to reveal the general principles of chromosome organization in bacteria. Here, drawing on studies of many different organisms, we review the emerging picture of how bacterial chromosomes are structured at multiple length-scales, highlighting the functions of various DNA-binding proteins and impact of physical forces. Additionally, we discuss the spatial dynamics of chromosomes, particularly during their segregation to daughter cells. Although there has been tremendous progress, we also highlight gaps that remain in understanding chromosome organization and segregation. PMID:26566111

Experimental investigation of the origin of fynbos plant community structure after fire.

PubMed

Silvertown, Jonathan; Araya, Yoseph N; Linder, H Peter; Gowing, David J

2012-11-01

Species in plant communities segregate along fine-scale hydrological gradients. Although this phenomenon is not unique to fynbos, this community regenerates after fire and therefore provides an opportunity to study the ecological genesis of hydrological niche segregation. Following wildfires at two field sites where we had previously mapped the vegetation and monitored the hydrology, seeds were moved experimentally in >2500 intact soil cores up and down soil-moisture gradients to test the hypothesis that hydrological niche segregation is established during the seedling phase of the life cycle. Seedling numbers and growth were then monitored and they were identified using DNA bar-coding, the first use of this technology for an experiment of this kind. At the site where niche segregation among Restionaceae had previously been found, the size of seedlings was significantly greater, the wetter the location into which they were moved, regardless of the soil moisture status of their location of origin, or of the species. Seedling weight was also significantly greater in a competition treatment where the roots of other species were excluded. No such effects were detected at the control site where niche segregation among Restionaceae was previously found to be absent. The finding that seedling growth on hydrological gradients in the field is affected by soil moisture status and by root competition shows that hydrological niche segregation could potentially originate in the seedling stage. The methodology, applied at a larger scale and followed-through for a longer period, could be used to determine whether species are differently affected by soil moisture.

Progressive retinal atrophy in the Border Collie: a new XLPRA.

PubMed

Vilboux, Thierry; Chaudieu, Gilles; Jeannin, Patricia; Delattre, Delphine; Hedan, Benoit; Bourgain, Catherine; Queney, Guillaume; Galibert, Francis; Thomas, Anne; André, Catherine

2008-03-03

Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG). Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests. Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3) and propose it as a potential model for the homologous human disease, X-Linked Retinitis Pigmentosa.

Molecular Mobility in Phase Segregated Bottlebrush Block Copolymer Melts

NASA Astrophysics Data System (ADS)

Yavitt, Benjamin; Gai, Yue; Song, Dongpo; Winter, H. Henning; Watkins, James

We investigate the linear viscoelastic behavior of poly(styrene)-block-poly(ethylene oxide) (PS-b-PEO) brush block copolymer (BBCP) materials over a range of vol. fractions and with side chain lengths below the entanglement molecular weights. The high chain mobility of the brush architecture results in rapid micro-phase segregation of the brush copolymer segments, which occurs during thermal annealing at mild temperatures. Master curves of the dynamic moduli were obtained by time-temperature superposition. The reduced degree of chain entanglements leads to a unique liquid-like rheology similar to that of bottlebrush homopolymers, even in the phase segregated state. We also explore the alignment of phase segregated domains at exceptionally low strain amplitudes (γ = 0.01) and mild processing temperatures using small angle X-ray scattering (SAXS). Domain orientation occurred readily at strains within the linear viscoelastic regime without noticeable effect on the moduli. This interplay of high molecular mobility and rapid phase segregation that are exhibited simultaneously in BBCPs is in contrast to the behavior of conventional linear block copolymer (LBCP) analogs and opens up new possibilities for processing BBCP materials for a wide range of nanotechnology applications. NSF Center for Hierarchical Manufacturing at the University of Massachusetts, Amherst (CMMI-1025020).

Enclaves of opportunity or "ghettos of last resort?" Assessing the effects of immigrant segregation on violent crime rates.

PubMed

Feldmeyer, Ben; Harris, Casey T; Scroggins, Jennifer

2015-07-01

A growing body of research indicates that immigration to the U.S. has crime-reducing effects on aggregate levels of violence, which researchers have often attributed to the protective and revitalizing effects of immigrants settling in spatially concentrated neighborhoods. However, recent scholarship suggests that growing shares of the foreign-born population are bypassing these segregated immigrant enclaves and are dispersing more widely to other urban neighborhoods. Moreover, some scholars suggest that spatially isolating immigrant populations may not always be protective, but could actually contribute to social problems like crime, particularly in disadvantaged contexts. The current study offers one of the first analyses exploring the way that segregation of immigrant populations (relative to the U.S.-born) is related to year 2000 violent crime rates for nearly 500 census places in California and New York. Results of our analysis reveal no direct link between immigrant segregation and macro-level violence, but instead show that these effects are highly contextualized and depend on the resources present in locales. Specifically, immigrant segregation contributes to violence in highly disadvantaged places but is linked to lower violence in areas with greater resources. Copyright © 2015 Elsevier Inc. All rights reserved.

The Evolution of Middle Schools.

ERIC Educational Resources Information Center

George, Paul S.

2001-01-01

Over the past 30 years, Florida's 500 middle schools have become more sizeable, racially segregated, and security conscious. Other features include interdisciplinary team organization, warring curricula, block schedules, integrated technology, inclusion, ability grouping, corporate practices, and female and minority principals committed to…

Segregation of impurities at γ' (L12) / γ (fcc) interfaces in a Ni-based superalloy

NASA Astrophysics Data System (ADS)

Tafen, De Nyago; Gao, Michael

2011-03-01

One of the most technologically advanced energy conversion devices is the gas turbine used in aerospace jet engines and gas- fired land-based turbines for electricity generation, fabricated from Ni-based superalloys. However, these materials lack of long- term mechanical and microstructure stability, which is largely due to an excessive coarsening of γ ' that can cause substantial loss of creep resistance and mechanical instability at high temperatures. Theoretical prediction of the creep rate of these important compounds is very imperative, but yet is extremely challenging. Interfacial energy is one of the most important factors that control the coarsening kinetics of these important phases. It indirectly determines the creep resistance of the alloy through the coarsening rate of the strengthening precipitate phase. In this talk, we will present the results of various γ ' / γ interfaces of a Ni-based superalloy obtained using DFT calculations. Then, we will discuss the segregation of impurities at these interfaces. Minor alloying elements in superalloys can alter the interfacial energy between γ and γ ' , and change the strength behavior of the alloy. Alloying elements or impurity species can segregate to interfaces. A favorable segregation would result in enhancing the interfacial cohesion and thus lower the energy.

HIV prevention interventions to reduce sexual risk for African Americans: the influence of community-level stigma and psychological processes.

PubMed

Reid, Allecia E; Dovidio, John F; Ballester, Estrellita; Johnson, Blair T

2014-02-01

Interventions to improve public health may benefit from consideration of how environmental contexts can facilitate or hinder their success. We examined the extent to which efficacy of interventions to improve African Americans' condom use practices was moderated by two indicators of structural stigma-Whites' attitudes toward African Americans and residential segregation in the communities where interventions occurred. A previously published meta-analytic database was re-analyzed to examine the interplay of community-level stigma with the psychological processes implied by intervention content in influencing intervention efficacy. All studies were conducted in the United States and included samples that were at least 50% African American. Whites' attitudes were drawn from the American National Election Studies, which collects data from nationally representative samples. Residential segregation was drawn from published reports. Results showed independent effects of Whites' attitudes and residential segregation on condom use effect sizes. Interventions were most successful when Whites' attitudes were more positive or when residential segregation was low. These two structural factors interacted: Interventions improved condom use only when communities had both relatively positive attitudes toward African Americans and lower levels of segregation. The effect of Whites' attitudes was more pronounced at longer follow-up intervals and for younger samples and those samples with more African Americans. Tailoring content to participants' values and needs, which may reduce African Americans' mistrust of intervention providers, buffered against the negative influence of Whites' attitudes on condom use. The structural factors uniquely accounted for variance in condom use effect sizes over and above intervention-level features and community-level education and poverty. Results highlight the interplay of social identity and environment in perpetuating intergroup disparities. Potential mechanisms for these effects are discussed along with public health implications. Copyright © 2013 Elsevier Ltd. All rights reserved.

HIV Prevention Interventions to Reduce Sexual Risk for African Americans: The Influence of Community-Level Stigma and Psychological Processes

PubMed Central

Reid, Allecia E.; Dovidio, John F.; Ballester, Estrellita; Johnson, Blair T.

2013-01-01

Interventions to improve public health may benefit from consideration of how environmental contexts can facilitate or hinder their success. We examined the extent to which efficacy of interventions to improve African Americans’ condom use practices was moderated by two indicators of structural stigma—Whites’ attitudes toward African Americans and residential segregation in the communities where interventions occurred. A previously published meta-analytic database was re-analyzed to examine the interplay of community-level stigma with the psychological processes implied by intervention content in influencing intervention efficacy. All studies were conducted in the United States and included samples that were at least 50% African American. Whites’ attitudes were drawn from the American National Election Studies, which collects data from nationally representative samples. Residential segregation was drawn from published reports. Results showed independent effects of Whites’ attitudes and residential segregation on condom use effect sizes. Interventions were most successful when Whites’ attitudes were more positive or when residential segregation was low. These two structural factors interacted: Interventions improved condom use only when communities had both relatively positive attitudes toward African Americans and lower levels of segregation. The effect of Whites’ attitudes was more pronounced at longer follow-up intervals and for younger samples and those samples with more African Americans. Tailoring content to participants’ values and needs, which may reduce African Americans’ mistrust of intervention providers, buffered against the negative influence of Whites’ attitudes on condom use. The structural factors uniquely accounted for variance in condom use effect sizes over and above intervention-level features and community-level education and poverty. Results highlight the interplay of social identity and environment in perpetuating intergroup disparities. Potential mechanisms for these effects are discussed along with public health implications. PMID:24507916

Alloy formation and metal oxide segregation in Pt-Re/. gamma. -Al/sub 2/O/sub 3/ catalysts as investigated by temperature-programmed reduction

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

Wagstaff, N.; Prins, R.

1979-10-15

Temperature-programmed reduction has been used to characterize the finely dispersed metal compounds in a series of Pt-Re/..gamma..-Al/sub 2/O/sub 3/ catalysts. Strong evidence has been obtained that zerovalent Pt and Re atoms are in intimate contact with each other after catalyst reduction. The formation of bimetallic clusters supports the alloy explanation for the improved performance of this type of bimetallic reforming catalyst. Treatment of the reduced catalysts with oxygen above about 200/sup 0/C causes segregation of platinum and rhenium oxides. Adsorption of oxygen at temperatures up to 100/sup 0/C leaves the bimetallic clusters largely intact, but subsequent high-temperature treatment in themore » absence of extra oxygen leads to segregation of Pt and Re species. This suggests that in the presence of adsorbed oxygen the Pt-Re clusters are thermodynamically unstable, but that under mild conditions the rate of segregation is slow. 10 figures, 4 tables.« less

Women's representation in 60 occupations from 1972 to 2010: more women in high-status jobs, few women in things-oriented jobs.

PubMed

Lippa, Richard A; Preston, Kathleen; Penner, John

2014-01-01

To explore factors associated with occupational sex segregation in the United States over the past four decades, we analyzed U.S. Bureau of Labor Statistics data for the percent of women employed in 60 varied occupations from 1972 to 2010. Occupations were assessed on status, people-things orientation, and data-ideas orientation. Multilevel linear modeling (MLM) analyses showed that women increasingly entered high-status occupations from 1972 to 2010, but women's participation in things-oriented occupations (e.g., STEM fields and mechanical and construction trades) remained low and relatively stable. Occupations' data-ideas orientation was not consistently related to sex segregation. Because of women's increased participation in high-status occupations, occupational status became an increasingly weak predictor of women's participation rates in occupations, whereas occupations' people-things orientation became an increasingly strong predictor over time. These findings are discussed in relation to theories of occupational sex segregation and social policies to reduce occupational sex segregation.

Women's Representation in 60 Occupations from 1972 to 2010: More Women in High-Status Jobs, Few Women in Things-Oriented Jobs

PubMed Central

Lippa, Richard A.; Preston, Kathleen; Penner, John

2014-01-01

To explore factors associated with occupational sex segregation in the United States over the past four decades, we analyzed U.S. Bureau of Labor Statistics data for the percent of women employed in 60 varied occupations from 1972 to 2010. Occupations were assessed on status, people-things orientation, and data-ideas orientation. Multilevel linear modeling (MLM) analyses showed that women increasingly entered high-status occupations from 1972 to 2010, but women's participation in things-oriented occupations (e.g., STEM fields and mechanical and construction trades) remained low and relatively stable. Occupations' data-ideas orientation was not consistently related to sex segregation. Because of women's increased participation in high-status occupations, occupational status became an increasingly weak predictor of women's participation rates in occupations, whereas occupations' people-things orientation became an increasingly strong predictor over time. These findings are discussed in relation to theories of occupational sex segregation and social policies to reduce occupational sex segregation. PMID:24788710

BubR1- and Polo-Coated DNA Tethers Facilitate Poleward Segregation of Acentric Chromatids

PubMed Central

Royou, Anne; Gagou, Mary E.; Karess, Roger; Sullivan, William

2010-01-01

Summary The mechanisms that safeguard cells against chromosomal instability (CIN) are of great interest, as CIN contributes to tumorigenesis. To gain insight into these mechanisms, we studied the behavior of cells entering mitosis with damaged chromosomes. We used the endonuclease I-CreI to generate acentric chromosomes in Drosophila larvae. While I-CreI expression produces acentric chromosomes in the majority of neuronal stem cells, remarkably, it has no effect on adult survival. Our live studies reveal that acentric chromatids segregate efficiently to opposite poles. The acentric chromatid poleward movement is mediated through DNA tethers decorated with BubR1, Polo, INCENP, and Aurora-B. Reduced BubR1 or Polo function results in abnormal segregation of acentric chromatids, a decrease in acentric chromosome tethering, and a great reduction in adult survival. We propose that BubR1 and Polo facilitate the accurate segregation of acentric chromatids by maintaining the integrity of the tethers that connect acentric chromosomes to their centric partners. PMID:20141837

Measures Matter: The Local Exposure/Isolation (LEx/Is) Metrics and Relationships Between Local Level Segregation and Breast Cancer Survival

PubMed Central

Bemanian, Amin; Beyer, Kirsten M.M.

2017-01-01

Background The Black to White disparity in breast cancer survival is increasing, and racial residential segregation is a potential driver for this trend. However, study findings have been mixed, and no study has comprehensively compared the effectiveness of different local level segregation metrics in explaining cancer survival. Methods We proposed a set of new local segregation metrics named LEx/Is (Local Exposure and Isolation) and compared our new local isolation metric to two related metrics - the location quotient (LQ) and the index of concentration at extremes (ICE) - across the 102 largest US metropolitan areas. Then, using case data from the Milwaukee, WI metropolitan area, we used proportional hazards models to explore associations between segregation and breast cancer survival. Results Across the 102 metropolitan areas, the new local isolation metric was less skewed than the LQ or ICE. Across all races, Hispanic isolation was associated with poorer all-cause survival, and Hispanic LQ and Hispanic-White ICE were found to be associated with poorer survival for both breast cancer specific and all-cause mortality. For Black patients, Black LQ was associated with lower all-cause mortality and Black local isolation was associated with reduced all-cause and breast cancer specific mortality. ICE was found to suffer from high multicollinearity. Conclusions Local segregation is associated with breast cancer survival, but associations varied based on patient race and metric employed. Impact We highlight how selection of a segregation measure can alter study findings. These relationships need to be validated in other geographic areas. PMID:28325737

Effect of La3+ substitution with Gd3+ on the resistive switching properties of La0.7Sr0.3MnO3 thin films

NASA Astrophysics Data System (ADS)

Lee, Hong-Sub; Park, Chang-Sun; Park, Hyung-Ho

2014-05-01

This study demonstrated that the resistive switching voltage of perovskite manganite material could be controlled by A-site cation substitution in "A" MnO3 perovskite manganite structure. A partial substitution of La3+ in La0.7Sr0.3MnO3 with smaller cation Gd3+ induced A-site vacancy of the largest Sr2+ cation with surface segregation of SrOy due to ionic size mismatch, and the induced vacancies reduced migration energy barrier. The operating voltage decreased from 3.5 V to 2.5 V due to a favorable condition for electrochemical migration and redox of oxygen ions. Moreover, surface-segregated SrOy was enhanced with Gd-substitution and the SrOy reduced Schottky-like barrier height and resistive switching ratio from the potential drop and screening effect. The relationship between A-site vacancy generation resulting in surface segregation of SrOy and resistive switching behavior was also investigated by energy resolved x-ray photoelectron spectroscopy, O 1s near edge x-ray absorption spectroscopy, and current voltage measurement.

RNAi-mediated resistance to whitefly (Bemisia tabaci) in genetically engineered lettuce (Lactuca sativa).

PubMed

Ibrahim, Abdulrazak B; Monteiro, Tatiane R; Cabral, Glaucia B; Aragão, Francisco J L

2017-10-01

RNA interference (RNAi)-based transgenic technologies have evolved as potent biochemical tools for silencing specific genes of plant pathogens and pests. The approach has been demonstrated to be useful in silencing genes in insect species. Here, we report on the successful construction of RNAi-based plasmid containing an interfering cassette designed to generate dsRNAs that target a novel v-ATPase transcript in whitefly (Bemisia tabaci), an important agricultural pest in tropical and sub-tropical regions. The presence of the transgene was confirmed in T 0 and T 1 generations of transgenic lettuce lines, segregating in a Mendelian fashion. Seven lines were infested with whiteflies and monitored over a period of 32 days. Analysis of mortality showed that within five days of feeding, insects on transgenic plants showed a mortality rate of 83.8-98.1%. In addition, a reduced number of eggs (95 fold less) was observed in flies feeding on transgenic lettuce plants than insects on control lines. Quantitative reverse transcription PCR showed decreased expression level of endogenous v-ATPase gene in whiteflies feeding on transgenic plants. This technology is a foundation for the production of whitefly-resistant commercial crops, improving agricultural sustainability and food security, reducing the use of more environmentally aggressive methods of pest control.

Grain Refinement and Improvement of Solidification Defects in Direct-Chill Cast Billets of A4032 Alloy by Melt Conditioning

NASA Astrophysics Data System (ADS)

Li, Hu-Tian; Zhao, Pizhi; Yang, Rongdong; Patel, Jayesh B.; Chen, Xiangfu; Fan, Zhongyun

2017-10-01

Melt-conditioned, direct-chill (MC-DC) casting is an emerging technology to manipulate the solidification process by melt conditioning via intensive shearing in the sump during DC casting to tailor the solidification microstructure and defect formation. When using MC-DC casting technology in an industrial scale DC cast billet of an A4032 aluminum alloy, significant grain refinement and uniform microstructure can be achieved in the primary α-Al phase with fine secondary dendritic arm spacing (SDAS). Improved macrosegregation is quantitatively characterized and correlated with the suppression of channel segregation. The mechanisms for the prevention of channel segregation are attributed to the increased local cooling rate in the liquid-solid phase region in the sump and the formation of fine equiaxed dendritic grains under intensive melt shearing during MC-DC casting. A critical cooling rate has been identified to be around 0.5 to 1 K/s (°C/s) for the channel segregation to happen in the investigated alloy based on quantitative metallographic results of SDAS. Reduction and refinement of microporosity is attributed to the improved permeability in the liquid-solid phase region estimated by the Kozeny-Carman relationship. The potential improvement in the mechanical properties achievable in MC-DC cast billets is indicated by the finer and more uniform forging streamline in the forgings of MC-DC cast billet.

Behavior of Aberrant Chromosome Configurations in Drosophila melanogaster Female Meiosis I

PubMed Central

Gilliland, William D.; Colwell, Eileen M.; Lane, Fiona M.; Snouffer, Ashley A.

2014-01-01

One essential role of the first meiotic division is to reduce chromosome number by half. Although this is normally accomplished by segregating homologous chromosomes from each other, it is possible for a genome to have one or more chromosomes that lack a homolog (such as compound chromosomes), or have chromosomes with multiple potential homologs (such as in XXY females). These configurations complete meiosis but engage in unusual segregation patterns. In Drosophila melanogaster females carrying two compound chromosomes, the compounds can accurately segregate from each other, a process known as heterologous segregation. Similarly, in XXY females, when the X chromosomes fail to cross over, they often undergo secondary nondisjunction, where both Xs segregate away from the Y. Although both of these processes have been known for decades, the orientation mechanisms involved are poorly understood. Taking advantage of the recent discovery of chromosome congression in female meiosis I, we have examined a number of different aberrant chromosome configurations. We show that these genotypes complete congression normally, with their chromosomes bioriented at metaphase I arrest at the same rates that they segregate, indicating that orientation must be established during prometaphase I before congression. We also show that monovalent chromosomes can move out on the prometaphase I spindle, but the dot 4 chromosomes appear required for this movement. Finally, we show that, similar to achiasmate chromosomes, heterologous chromosomes can be connected by chromatin threads, suggesting a mechanism for how heterochromatic homology establishes these unusual biorientation patterns. PMID:25491942

Behavior of aberrant chromosome configurations in Drosophila melanogaster female meiosis I.

PubMed

Gilliland, William D; Colwell, Eileen M; Lane, Fiona M; Snouffer, Ashley A

2014-12-09

One essential role of the first meiotic division is to reduce chromosome number by half. Although this is normally accomplished by segregating homologous chromosomes from each other, it is possible for a genome to have one or more chromosomes that lack a homolog (such as compound chromosomes), or have chromosomes with multiple potential homologs (such as in XXY females). These configurations complete meiosis but engage in unusual segregation patterns. In Drosophila melanogaster females carrying two compound chromosomes, the compounds can accurately segregate from each other, a process known as heterologous segregation. Similarly, in XXY females, when the X chromosomes fail to cross over, they often undergo secondary nondisjunction, where both Xs segregate away from the Y. Although both of these processes have been known for decades, the orientation mechanisms involved are poorly understood. Taking advantage of the recent discovery of chromosome congression in female meiosis I, we have examined a number of different aberrant chromosome configurations. We show that these genotypes complete congression normally, with their chromosomes bioriented at metaphase I arrest at the same rates that they segregate, indicating that orientation must be established during prometaphase I before congression. We also show that monovalent chromosomes can move out on the prometaphase I spindle, but the dot 4 chromosomes appear required for this movement. Finally, we show that, similar to achiasmate chromosomes, heterologous chromosomes can be connected by chromatin threads, suggesting a mechanism for how heterochromatic homology establishes these unusual biorientation patterns. Copyright © 2015 Gilliland et al.

Novel Method for Making Biomedical Segregation-Free Ti-30Ta Alloy Spherical Powder for Additive Manufacturing

NASA Astrophysics Data System (ADS)

Xia, Yang; Fang, Zhigang Zak; Sun, Pei; Zhang, Ying; Zhu, Jun

2018-03-01

Ti-Ta alloys offer a good combination of high strength and low modulus among Ti-based alloys, and are ideal for biomedical applications. However, making Ti-Ta alloys has always been challenging because they tend to suffer from compositional segregation during melting due to the large difference between the melting points of Ti and Ta. This article describes a novel process for making spherical Ti-30Ta alloy powder through a unique powder metallurgy technique, namely the granulation-sintering-deoxygenation process. The results indicate that the compositional segregation problem can be overcome using this process technology. Combined with use of a deoxygenation process, the critical interstitial element, oxygen, can be controlled to < 400 ppm for powder with particle size < 75 µm. The destabilization effect of Ta on Ti-O solid solutions, and the resulting improved deoxygenation process for Ti-Ta, are discussed, as well as the phase composition and microstructure of the powders.

Measures Matter: The Local Exposure/Isolation (LEx/Is) Metrics and Relationships between Local-Level Segregation and Breast Cancer Survival.

PubMed

Bemanian, Amin; Beyer, Kirsten M M

2017-04-01

Background: The Black-to-White disparity in breast cancer survival is increasing, and racial residential segregation is a potential driver for this trend. However, study findings have been mixed, and no study has comprehensively compared the effectiveness of different local-level segregation metrics in explaining cancer survival. Methods: We proposed a set of new local segregation metrics named local exposure and isolation (LEx/Is) and compared our new local isolation metric with two related metrics, the location quotient (LQ) and the index of concentration at extremes (ICE), across the 102 largest U.S. metropolitan areas. Then, using case data from the Milwaukee, WI, metropolitan area, we used proportional hazards models to explore associations between segregation and breast cancer survival. Results: Across the 102 metropolitan areas, the new local isolation metric was less skewed than the LQ or ICE. Across all races, Hispanic isolation was associated with poorer all-cause survival, and Hispanic LQ and Hispanic-White ICE were found to be associated with poorer survival for both breast cancer-specific and all-cause mortality. For Black patients, Black LQ was associated with lower all-cause mortality and Black local isolation was associated with reduced all-cause and breast cancer-specific mortality. ICE was found to suffer from high multicollinearity. Conclusions: Local segregation is associated with breast cancer survival, but associations varied based on patient race and metric employed. Impact: We highlight how selection of a segregation measure can alter study findings. These relationships need to be validated in other geographic areas. Cancer Epidemiol Biomarkers Prev; 26(4); 516-24. ©2017 AACR See all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences." ©2017 American Association for Cancer Research.

The residential segregation of detailed Hispanic and Asian groups in the United States: 1980-2010

PubMed Central

Weinberg, Daniel; Hughes, Lauren

2015-01-01

Background Racial and ethnic diversity continues to grow in communities across the United States, raising questions about the extent to which different ethnic groups will become residentially integrated. Objective While a number of studies have examined the residential patterns of pan-ethnic groups, our goal is to examine the segregation of several Asian and Hispanic ethnic groups – Cubans, Dominicans, Mexicans, Puerto Ricans, Salvadorans, Asian Indians, Chinese, Filipinos, Japanese, Koreans, and Vietnamese. We gauge the segregation of each group from several alternative reference groups using two measures over the 1980 to 2010 period. Results We find that the dissimilarity of Hispanics and Asians from other groups generally held steady or declined, though, because most Hispanic and Asian groups are growing, interaction with Whites also often declined. Our analyses also indicate that pan-ethnic segregation indexes do not always capture the experience of specific groups. Among Hispanics, Mexicans are typically less residentially segregated (as measured using the dissimilarity index) from Whites, Blacks, Asians, and other Hispanics than are other Hispanic-origin groups. Among Asian ethnic groups, Japanese and Filipinos tend to have lower levels of dissimilarity from Whites, Blacks, and Hispanics than other Asian groups. Examining different dimensions of segregation also indicates that dissimilarity scores alone often do not capture to what extent various ethnic groups are actually sharing neighborhoods with each other. Finally, color lines vary across groups in some important ways, even as the dominant trend has been toward reduced racial and ethnic residential segregation over time. Conclusions The overarching trend is that ethnic groups are becoming more residentially integrated, suggestive of assimilation, though there is significant variation across ethnic groups. PMID:26097412

Impurity effects on the grain boundary cohesion in copper

NASA Astrophysics Data System (ADS)

Li, Yunguo; Korzhavyi, Pavel A.; Sandström, Rolf; Lilja, Christina

2017-12-01

Segregated impurities at grain boundaries can dramatically change the mechanical behavior of metals, while the mechanism is still obscure in some cases. Here, we suggest a unified approach to investigate segregation and its effects on the mechanical properties of polycrystalline alloys using the example of 3 s p impurities (Mg, Al, Si, P, or S) at a special type Σ 5 (310 )[001 ] tilt grain boundary in Cu. We show that for these impurities segregating to the grain boundary, the strain contribution to the work of grain boundary decohesion is small and that the chemical contribution correlates with the electronegativity difference between Cu and the impurity. The strain contribution to the work of dislocation emission is calculated to be negative, while the chemical contribution is calculated to be always positive. Both the strain and chemical contributions to the work of dislocation emission generally become weaker with the increasing electronegativity from Mg to S. By combining these contributions together, we find, in agreement with experimental observations, that a strong segregation of S can reduce the work of grain boundary separation below the work of dislocation emission, thus embrittling Cu, while such an embrittlement cannot be produced by a P segregation because it lowers the energy barrier for dislocation emission relatively more than for work separation.

Progressive Retinal Atrophy in the Border Collie: A new XLPRA

PubMed Central

Vilboux, Thierry; Chaudieu, Gilles; Jeannin, Patricia; Delattre, Delphine; Hedan, Benoit; Bourgain, Catherine; Queney, Guillaume; Galibert, Francis; Thomas, Anne; André, Catherine

2008-01-01

Background Several forms of progressive retinal atrophy (PRA) segregate in more than 100 breeds of dog with each PRA segregating in one or a few breeds. This breed specificity may be accounted for by founder effects and genetic drift, which have reduced the genetic heterogeneity of each breed, thereby facilitating the identification of causal mutations. We report here a new form of PRA segregating in the Border Collie breed. The clinical signs, including the loss of night vision and a progressive loss of day vision, resulting in complete blindness, occur at the age of three to four years and may be detected earlier through systematic ocular fundus examination and electroretinography (ERG). Results Ophthalmic examinations performed on 487 dogs showed that affected dogs present a classical form of PRA. Of those, 274 have been sampled for DNA extraction and 87 could be connected through a large pedigree. Segregation analysis suggested an X-linked mode of transmission; therefore both XLPRA1 and XLPRA2 mutations were excluded through the genetic tests. Conclusion Having excluded these mutations, we suggest that this PRA segregating in Border Collie is a new XLPRA (XLPRA3) and propose it as a potential model for the homologous human disease, X-Linked Retinitis Pigmentosa. PMID:18315866

A sulfur segregation study of PWA 1480, NiCrAl, and NiAl alloys

NASA Technical Reports Server (NTRS)

Jayne, D. T.; Smialek, J. L.

1993-01-01

Some nickel based superalloys show reduced oxidation resistance from the lack of an adherent oxide layer during high temperature cyclic oxidation. The segregation of sulfur to the oxide-metal interface is believed to effect oxide adhesion, since low sulfur alloys exhibit enhanced adhesion. X ray Photoelectron Spectroscopy (XPS) was combined with an in situ sample heater to measure sulfur segregation in NiCrAl, PWA 1480, and NiAl alloys. The polished samples with a 1.5 to 2.5 nm (native) oxide were heated from 650 to 1100 C with hold times up to 6 hr. The sulfur concentration was plotted as a function of temperature versus time at temperature. One NiCrAl sulfur study was performed on the same casting used by Browning to establish a base line between previous Auger Electron Spectroscopy (AES) results and the XPS results of this study. Sulfur surface segregation was similar for PWA 1480 and NiCrAl and reached a maximum of 30 at% at 800 to 850 C. Above 900 C the sulfur surface concentration decreased to about 3 at% at 1100 C. These results are contrasted to the minimal segregation observed for low sulfur hydrogen annealed materials which exhibit improved scale adhesion.

Microgravity Segregation in Binary Mixtures of Inelastic Spheres Driven by Velocity Fluctuation Gradients

NASA Technical Reports Server (NTRS)

Jenkins, James T.; Louge, Michel Y.

1996-01-01

We are interested in collisional granular flows of dry materials in reduced gravity. Because the particles interact through collisions, the energy of the particle velocity fluctuations plays an important role in the physics. Here we focus on the separation of grains by properties - size, for example - that is driven by spatial gradients in the fluctuation energy of the grains. The segregation of grains by size is commonly observed in geophysical flows and industrial processes. Segregation of flowing grains can also take place based on other properties, e.g. shape, mass, friction, and coefficient of restitution. Many mechanisms may be responsible for segregation; most of these are strongly influenced by gravity. Here, we outline a mechanism that is independent of gravity. This mechanism may be important but is often obscured in terrestrial grain flows. It is driven by gradients in fluctuation energy. In microgravity, the separation of grains by property will proceed slowly enough to permit flight observations to provide an unambiguous measurement of the transport coefficients associated with the segregation. In this context, we are planning a microgravity shear cell experiment that contains a mixture of two types of spherical grains. The grains will be driven to interact with two different types of boundaries on either sides of the cell. The resulting separation will be observed visually.

Assessment of Intergenerational Communication and Relationships

ERIC Educational Resources Information Center

Strom, Robert D.; Strom, Paris S.

2015-01-01

The revolution in communication technology has resulted in more age-segregated conversation among adolescents. In a similar way, older adults have increased online conversations with their peers. This article explores some obstacles that prevent the intergenerational connections needed for mutual understanding and care. Several research emphases…

Gender Equity: Still Knocking at the Classroom Door.

ERIC Educational Resources Information Center

Sadker, David

1999-01-01

Subtlety and complacency mask ongoing gender bias in today's classrooms. Updates are presented concerning career segregation; single-sex classrooms; safety and health problems; dropout rates; gifted programs; male/female stereotypes; classroom interactions; SAT scores; math, science and technology gender gaps; political reversals; and female…

Does zoning winter recreationists reduce recreation conflict?

Treesearch

Aubrey Miller; Jerry J. Vaske; John R. Squires; Lucretia E. Olson

2016-01-01

Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation - often by nonmotorized and motorized activity - is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation...

Does zoning winter recreationists reduce recreation conflict?

Treesearch

Aubrey D. Miller; Jerry J. Vaske; John R. Squires; Lucretia E. Olson; Elizabeth K. Roberts

2017-01-01

Parks and protected area managers use zoning to decrease interpersonal conflict between recreationists. Zoning, or segregation, of recreation - often by nonmotorized and motorized activity - is designed to limit physical interaction while providing recreation opportunities to both groups. This article investigated the effectiveness of zoning to reduce recreation...

Reduced grain boundary energies in rare-earth doped MgAl 2O 4 spinel and consequent grain growth inhibition

DOE PAGES

Hasan, Md M.; Dholabhai, Pratik P.; Dey, Sanchita; ...

2017-05-15

In this paper, grain growth inhibition in MgAl 2O 4 spinel nanostructure was achieved by grain boundary (GB) segregation of rare-earth dopants. Microcalorimetric measurements showed that dense spinel compacts doped with 3 mol% of R 2O 3 (R = Y, Gd, and La) had decreased GB energies as compared to the undoped spinel, representing reduction in the driving force for grain growth. Segregation energies of the three dopants to the Σ3 (111) GB were calculated by atomistic simulation. The dopants with higher ionic radius tend to segregate more strongly to GBs. The GB energies were calculated from atomistic simulation and,more » consistent with experiments, a systematic reduction in GB energy with dopant ionic size was found. Finally, high temperature grain growth experiments revealed a significant reduction of grain growth in the doped nanostructures as compared to the undoped one, which was attributed to increased metastability or possibly also a GB dragging originated from the dopant segregation.« less

Altered Brain Network Segregation in Fragile X Syndrome Revealed by Structural Connectomics.

PubMed

Bruno, Jennifer Lynn; Hosseini, S M Hadi; Saggar, Manish; Quintin, Eve-Marie; Raman, Mira Michelle; Reiss, Allan L

2017-03-01

Fragile X syndrome (FXS), the most common inherited cause of intellectual disability and autism spectrum disorder, is associated with significant behavioral, social, and neurocognitive deficits. Understanding structural brain network topology in FXS provides an important link between neurobiological and behavioral/cognitive symptoms of this disorder. We investigated the connectome via whole-brain structural networks created from group-level morphological correlations. Participants included 100 individuals: 50 with FXS and 50 with typical development, age 11-23 years. Results indicated alterations in topological properties of structural brain networks in individuals with FXS. Significantly reduced small-world index indicates a shift in the balance between network segregation and integration and significantly reduced clustering coefficient suggests that reduced local segregation shifted this balance. Caudate and amygdala were less interactive in the FXS network further highlighting the importance of subcortical region alterations in the neurobiological signature of FXS. Modularity analysis indicates that FXS and typically developing groups' networks decompose into different sets of interconnected sub networks, potentially indicative of aberrant local interconnectivity in individuals with FXS. These findings advance our understanding of the effects of fragile X mental retardation protein on large-scale brain networks and could be used to develop a connectome-level biological signature for FXS. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Mixing and diffusion in a two-type population.

PubMed

Izquierdo, Segismundo S; Izquierdo, Luis R; López-Pintado, Dunia

2018-02-01

The outbreak of epidemics, the rise of religious radicalization or the motivational influence of fellow students in classrooms are some of the issues that can be described as diffusion processes in heterogeneous groups. Understanding the role that interaction patterns between groups (e.g. homophily or segregation) play in the diffusion of certain traits or behaviours is a major challenge for contemporary societies. Here, we study the impact on diffusion processes of mixing (or, alternatively, segregating) two groups that present different sensitivities or propensities to contagion. We find non-monotonic effects of mixing and inefficient segregation levels, i.e. situations where a change in the mixing level can benefit both groups, e.g. where an increase in the mixing level can reduce the expected contagion levels in both groups. These findings can have fundamental consequences for the design of inclusion policies.

Perceptual multistability in figure-ground segregation using motion stimuli.

PubMed

Gori, Simone; Giora, Enrico; Pedersini, Riccardo

2008-11-01

In a series of experiments using ambiguous stimuli, we investigate the effects of displaying ordered, discrete series of images on the dynamics of figure-ground segregation. For low frame presentation speeds, the series were perceived as a sequence of discontinuous, static images, while for high speeds they were perceived as continuous. We conclude that using stimuli varying continuously along one parameter results in stronger hysteresis and reduces spontaneous switching compared to matched static stimuli with discontinuous parameter changes. The additional evidence that the size of the hysteresis effects depended on trial duration is consistent with the stochastic nature of the dynamics governing figure-ground segregation. The results showed that for continuously changing stimuli, alternative figure-ground organizations are resolved via low-level, dynamical competition. A second series of experiments confirmed these results with an ambiguous stimulus based on Petter's effect.

Mixing and diffusion in a two-type population

PubMed Central

López-Pintado, Dunia

2018-01-01

The outbreak of epidemics, the rise of religious radicalization or the motivational influence of fellow students in classrooms are some of the issues that can be described as diffusion processes in heterogeneous groups. Understanding the role that interaction patterns between groups (e.g. homophily or segregation) play in the diffusion of certain traits or behaviours is a major challenge for contemporary societies. Here, we study the impact on diffusion processes of mixing (or, alternatively, segregating) two groups that present different sensitivities or propensities to contagion. We find non-monotonic effects of mixing and inefficient segregation levels, i.e. situations where a change in the mixing level can benefit both groups, e.g. where an increase in the mixing level can reduce the expected contagion levels in both groups. These findings can have fundamental consequences for the design of inclusion policies. PMID:29515903

Mitochondrial fission proteins Fis1 and Mdv1, but not Dnm1, play a role in maintenance of heteroplasmy in budding yeast.

PubMed

Bradshaw, Elliot; Yoshida, Minoru; Ling, Feng

2012-04-24

In budding yeast, the mitochondrial DNA (mtDNA) replication pathway involving the homologous DNA pairing protein Mhr1 promotes mitochondrial allele segregation. Mitochondrial fusion facilitates the recombination-mediated replication pathway; however, the role of fission remains largely unknown. By monitoring mitochondrial allele segregation during zygotic division, we found that the absence of fission proteins Fis1 or Mdv1, but not Dnm1, resulted in increased initial homoplasmy levels and decreased mtDNA copy number. However, decreases in mtDNA copy number alone were not sufficient for rapid establishment of homoplasmy, suggesting that inhibiting the activities of certain fission proteins promotes homoplasmy by reducing the number of mtDNA segregation units. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Ring-shaped stain patterns driven by solute reactive mesogens in liquid crystal solution

NASA Astrophysics Data System (ADS)

Cha, Tae Woon; Bulliard, Xavier; Choi, Sang Gun; Lee, Hyoung Sub; Kong, Hyang-Shik; Han, Sang Youn

2014-07-01

We report on the formation of ring-shaped stain patterns in a polymer-stabilized patterned vertical alignment mode liquid crystal display (LCD) during the cell filling process. Through the interpretation of the formation mechanism, an effective way to control its development is provided. Systematic trace of the reactive mesogens reveals that the formation of patterns is strongly related to the segregation of solute mesogens in the stain area. These undesirable patterns can be avoided or controlled by reducing the drop volume at each droplet using an inkjet printing technique, meaning that the printing technique could be a useful solution in display technology. For the formation of ring-shaped patterns, the dragging of reactive mesogens during the spreading of the liquid crystal solution plays a key role in the closed LCD cell.

African-American Medical Personnel in the US Army in the First World War.

PubMed

Marble, Sanders

2018-02-01

In WWI, the United States was segregated by custom and law, and the Army obeyed the laws, reducing opportunities for Black medical professionals to serve their country in uniform. This article surveys African-American medical personnel serving in the US Army in World War I. It includes physicians, dentists, veterinarians, and other commissioned officers, as well as medical enlisted men. Overall, despite segregation and associated professional limitations, determined individuals still served with distinction in a variety of roles, opening doors for future advances. Published by Elsevier Inc.

Racial residential segregation, socioeconomic disparities, and the White-Black survival gap.

PubMed

Popescu, Ioana; Duffy, Erin; Mendelsohn, Joshua; Escarce, José J

2018-01-01

To evaluate the association between racial residential segregation, a prominent manifestation of systemic racism, and the White-Black survival gap in a contemporary cohort of adults, and to assess the extent to which socioeconomic inequality explains this association. This was a cross sectional study of White and Black men and women aged 35-75 living in 102 large US Core Based Statistical Areas. The main outcome was the White-Black survival gap. We used 2009-2013 CDC mortality data for Black and White men and women to calculate age-, sex- and race adjusted White and Black mortality rates. We measured segregation using the Dissimilarity index, obtained from the Manhattan Institute. We used the 2009-2013 American Community Survey to define indicators of socioeconomic inequality. We estimated the CBSA-level White-Black gap in probability of survival using sequential linear regression models accounting for the CBSA dissimilarity index and race-specific socioeconomic indicators. Black men and women had a 14% and 9% lower probability of survival from age 35 to 75 than their white counterparts. Residential segregation was strongly associated with the survival gap, and this relationship was partly, but not fully, explained by socioeconomic inequality. At the lowest observed level of segregation, and with the Black socioeconomic status (SES) assumed to be at the White SES level scenario, the survival gap is essentially eliminated. White-Black differences in survival remain wide notwithstanding public health efforts to improve life expectancy and initiatives to reduce health disparities. Eliminating racial residential segregation and bringing Black socioeconomic status (SES) to White SES levels would eliminate the White-Black survival gap.

An agent-based simulation of persistent inequalities in health behavior: Understanding the interdependent roles of segregation, clustering, and social influence.

PubMed

Langellier, Brent A

2016-12-01

Health inequalities are conspicuously persistent through time and often durable even in spite of interventions. In this study, I use agent-based simulation models (ABMs) to understand how the complex interrelationships between residential segregation, social network formation, group-level preferences, and social influence may contribute to this persistence. I use a more-stylized ABM, Bubblegum Village (BV), to understand how initial inequalities in bubblegum-chewing behaviors either endure, increase, or decrease over time given group-level differences in preferences, neighborhood-level barriers or facilitators of bubblegum chewing (e.g., access to bubblegum shops), and agents' preferences for segregation, homophily, and clustering (i.e., the 'tightness' of social networks). I further use BV to understand whether segregation and social network characteristics impact whether the effects of a bubblegum-reduction intervention that is very effective in the short term are durable over time, as well as to identify intervention strategies to reduce attenuation of the intervention effects. In addition to BV, I also present results from an ABM based on the distribution and social characteristics of the population in Philadelphia, PA. This model explores similar questions to BV, but examines racial/ethnic inequalities in soda consumption based on agents' social characteristics and baseline soda consumption probabilities informed by the 2007-2010 National Health and Nutrition Examination Survey. Collectively, the models suggest that residential segregation is a fundamental process for the production and persistence of health inequalities. The other major conclusion of the study is that, for behaviors that are subject to social influence and that cluster within social groups, interventions that are randomly-targeted to individuals with 'bad' behaviors will likely experience a large degree of recidivism to pre-intervention behaviors. In contrast, interventions that target multiple members of the same network, as well as multilevel interventions that include a neighborhood-level component, can reduce recidivism.

Perceived Mathematical Ability under Challenge: A Longitudinal Perspective on Sex Segregation among STEM Degree Fields

ERIC Educational Resources Information Center

Nix, Samantha; Perez-Felkner, Lara; Thomas, Kirby

2015-01-01

Students' perceptions of their mathematics ability vary by gender and seem to influence science, technology, engineering, and mathematics (STEM) degree choice. Related, students' perceptions during academic difficulty are increasingly studied in educational psychology, suggesting a link between such perceptions and task persistence. Despite…

TECHNOLOGY EVALUATION REPORT: BIOTROL SOIL WASHING SYSTEM FOR TREATMENT OF A WOOD PRESERVING SITE - VOLUME I

EPA Science Inventory

The report presents and evaluates the extensive database from the SITE Program demonstration at the MacGillis and Gibbs wood treatment facility in New Brighton, MN. Soil washing and segregation, biotreatment of contaminated process water, and biodegradation of a slurry of the con...

Can ICT Give Children with Disabilities Equal Opportunities in School?

ERIC Educational Resources Information Center

Brodin, Jane

2010-01-01

Opportunities for children with disabilities to participate in school on equal conditions as others are often stressed, while reality shows that many children with disabilities are still segregated. Information and Communication Technology (ICT) has been highlighted as a tool for communication and inclusion for children with disabilities but from…

Engineering and the Liberal Arts: Strangers No Longer

ERIC Educational Resources Information Center

Chronicle of Higher Education, 2008

2008-01-01

Colleges and universities increasingly view engineering as an important part of a liberal-arts education. Rather than segregate engineering from the arts and humanities, they are integrating the disciplines, in hopes of educating students to perform more effectively in an increasingly complex and technological world. Several college presidents,…

Qualitative numerical study of simultaneous high-G-intensified gas–solids contact, separation and segregation in a bi-disperse rotating fluidized bed in a vortex chamber

DOE PAGES

De Wilde, Juray; Richards, George; Benyahia, Sofiane

2016-05-13

Coupled discrete particle method – computational fluid dynamics simulations are carried out to demonstrate the potential of combined high-G-intensified gas-solids contact, gas-solids separation and segregation in a rotating fluidized bed in a static vortex chamber. A case study with two distinct types of particles is focused on. When feeding solids using a standard solids inlet design, a dense and uniform rotating fluidized bed is formed, guaranteeing intense gas-solids contact. The presence of both types of particles near the chimney region reduces, however, the strength of the central vortex and is detrimental for separation and segregation. Optimization of the solids inletmore » design is required, as illustrated by stopping the solids feeding. High-G separation and segregation of the batch of particles is demonstrated, as the strength of the central vortex is restored. The flexibility with respect to the gas flow rate of the bed density and uniformity and of the gas-solids separation and segregation is demonstrated, a unique feature of vortex chamber generated rotating fluidized beds. With the particles considered in this case study, turbulent dispersion by large eddies in the gas phase is shown to have only a minor impact on the height of the inner bed of small/light particles.« less

Loss of sexual recombination and segregation is associated with increased diversification in evening primroses.

PubMed

Johnson, Marc T J; Fitzjohn, Richard G; Smith, Stacey D; Rausher, Mark D; Otto, Sarah P

2011-11-01

The loss of sexual recombination and segregation in asexual organisms has been portrayed as an irreversible process that commits asexually reproducing lineages to reduced diversification. We test this hypothesis by estimating rates of speciation, extinction, and transition between sexuality and functional asexuality in the evening primroses. Specifically, we estimate these rates using the recently developed BiSSE (Binary State Speciation and Extinction) phylogenetic comparative method, which employs maximum likelihood and Bayesian techniques. We infer that net diversification rates (speciation minus extinction) in functionally asexual evening primrose lineages are roughly eight times faster than diversification rates in sexual lineages, largely due to higher speciation rates in asexual lineages. We further reject the hypothesis that a loss of recombination and segregation is irreversible because the transition rate from functional asexuality to sexuality is significantly greater than zero and in fact exceeded the reverse rate. These results provide the first empirical evidence in support of the alternative theoretical prediction that asexual populations should instead diversify more rapidly than sexual populations because they are free from the homogenizing effects of sexual recombination and segregation. Although asexual reproduction may often constrain adaptive evolution, our results show that the loss of recombination and segregation need not be an evolutionary dead end in terms of diversification of lineages. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

A high incidence of adjacent-1 meiotic segregation pattern, revealed by multicolor sperm FISH, in a carrier boar of a new reciprocal translocation t(6;16)(p13;q23).

PubMed

Kociucka, B; Szczerbal, I; Bugaj, S; Orsztynowicz, M; Switonski, M

2014-01-01

Reciprocal translocations pose a serious problem in pig breeding due to the reduced fertility of the carriers. This paper presents a new reciprocal translocation in a phenotypically normal, but hypoprolific (20% reduction) boar. Chromosome banding as well as the FISH technique with the use of BAC and telomeric probes was applied for a detailed characterization of this chromosome rearrangement. The karyotype of the studied boar was described as 38,XY,t(6;16)(p13;q23). The meiotic segregation of the quadrivalent was studied in 1,071 sperms by multicolor FISH. The most frequent segregation patterns were alternate (47.5%) and adjacent 1 (41.9%), while adjacent 2 and 3:1 were less frequent at 1.2 and 9.2%, respectively. Surprisingly, the frequency of the adjacent-1 segregation appeared to be relatively high, when compared with human and pig reciprocal translocations studied by sperm FISH. Our study, along with a review of the literature, shows that a reduction of fertility in the carriers and the incidence of different segregation patterns of the quadrivalent may vary within a broad range, and both aspects seem to be unrelated. A need for obligatory karyotype screening programs of artificial insemination boars is emphasized. © 2013 S. Karger AG, Basel.

Heat flow control and segregation in directional solidification: Development of an experimental and theoretical basis for Bridgman-type growth experiments in a microgravity environment

NASA Technical Reports Server (NTRS)

Witt, A. F.

1986-01-01

Within the framework of the proposed research, emphasis was placed on application of magnetic fields to semiconductor growth systems. It was found that magnetic fields up to 3 kGauss do not affect the growth behavior nor the macro-segregation behavior in the system Ge(Ga). Applied fields are found to significantlty alter the radial dopant distribution, which is attributed to alterations in the spatial orientation of convective cells. Increasing the magnetic field to 30 kGauss is found to have a fundamental effect on dopant segregation. Emphasis is also placed on the potential of KC-135 flights for preliminary studies on the effects of reduced gravity environments on the wetting behavior of semiconductor systems in growth configuration. The limited number of experiments conducted does not allow any conclusions on the merits of KC-135 flights for semiconductor processing research.

Repression of harmful meiotic recombination in centromeric regions

PubMed Central

Nambiar, Mridula; Smith, Gerald R.

2016-01-01

During the first division of meiosis, segregation of homologous chromosomes reduces the chromosome number by half. In most species, sister chromatid cohesion and reciprocal recombination (crossing-over) between homologous chromosomes are essential to provide tension to signal proper chromosome segregation during the first meiotic division. Crossovers are not distributed uniformly throughout the genome and are repressed at and near the centromeres. Rare crossovers that occur too near or in the centromere interfere with proper segregation and can give rise to aneuploid progeny, which can be severely defective or inviable. We review here how crossing-over occurs and how it is prevented in and around the centromeres. Molecular mechanisms of centromeric repression are only now being elucidated. However, rapid advances in understanding crossing-over, chromosome structure, and centromere functions promise to explain how potentially deleterious crossovers are avoided in certain chromosomal regions while allowing beneficial crossovers in others. PMID:26849908

A highly efficient, cell-free translation/translocation system prepared from Xenopus eggs.

PubMed Central

Matthews, G; Colman, A

1991-01-01

We describe the use of a Xenopus laevis egg extract for the in vitro translation and post translational modification of membrane and secretory proteins. This extract is capable of the translation and segregation into membranes of microgram per millilitre levels of protein from added mRNAs. Signal sequences of segregated proteins are efficiently cleaved and appropriate N-linked glycosylation patterns are produced. The extract also supports the quantitative assembly of murine immunoglobulin heavy and light chains into tetramers, and two events which take place beyond the endoplasmic reticulum, mannose 6 phosphorylation of murine cathepsin D and O-linked glycosylation of coronavirus E1 protein, also occur, but at reduced efficiency. The stability of the membranes allows protease protection studies and quantitative centrifugal fractionation of segregated and unsegregated proteins to be performed. Conditions for the use of stored extract have also been determined. Images PMID:1754376

Centrifugal casting of ZA8 zinc alloy and composite A356/silicon carbide: Study and modeling of phases' and particles' segregation

NASA Astrophysics Data System (ADS)

Balout, Bahaa

Centrifugation is a casting technology that allows the production of cylindrical and graduated parts with different mechanical properties through the section. The need for materials with good quality and specific mechanical properties has been driven this technology in order to produce different types of materials such as zinc alloys and graduated metal matrix composites reinforced by hard and wear resistant particles. The goal of this research project is to study and model the eutectic macrosegregation, the solidification speed, and the speeds of solidification fronts during centrifugal casting of ZA8 zinc-aluminum alloy in order to improve the part quality and increase its strength and field reliability. Moreover, the segregation of the particles during centrifugal casting of an aluminum matrix composite reinforced by silicon carbide particles (A356/SiC) is also studied to improve and control the graduation of the parts. The cooling rate, the speed, acceleration/deceleration, displacement, and segregation of the particles across the section will be modeled by discretization of Stokes' law in time in order to take into consideration the change in the centrifugal radius and melt viscosity during cooling process. This study will allow the control of the graduation degree of particles across the section in order to improve the properties and wear resistance of the composite. This composite can be used in systems where friction is critical and load is high (reinforcements of parts for the cylinders of pneumatic systems). The results show that the maximum macrosegregation zone of the eutectic across the casting section corresponds to the last point of solidification. The eutectic macrosegregation produced during centrifugal casting of thin walled part is a normal segregation which varies depending on the solidification speed and the ratio between the speeds of solidification fronts. On the other hand, it was found that the position and volume fraction of the particles on the outer/inner casting surface and across the section varies whether the viscosity of the liquid metal used and the centrifugal radius are considered constant or variable during the modeling. Modeling the particles' segregation while discretizing, in time, the particles' velocities gives more consistent results compared to those obtained experimentally. Key-words: centrifugal casting, composite, macrosegregation, solidification.

Urban segregation and the US heroin market: a quantitative model of anthropological hypotheses from an inner-city drug market.

PubMed

Rosenblum, Daniel; Castrillo, Fernando Montero; Bourgois, Philippe; Mars, Sarah; Karandinos, George; Unick, George Jay; Ciccarone, Daniel

2014-05-01

We hypothesize that the location of highly segregated Hispanic and in particular Puerto Rican neighborhoods can explain how Colombian-sourced heroin, which is associated with a large-scale decade long decline in heroin price and increase in purity, was able to enter and proliferate in the US. Our multidisciplinary analysis quantitatively operationalizes participant-observation ethnographic hypotheses informed by social science theory addressing complex political economic, historical, cultural and social processes. First, we ethnographically document the intersection of structural forces shaping Philadelphia's hypersegregated Puerto Rican community as a regional epicenter of the US heroin market. Second, we estimate the relationship between segregation and: (a) the entry of Colombian heroin into the US, and (b) the retail price per pure gram of heroin in 21 Metropolitan Statistical Areas. Ethnographic evidence documents how poverty, historically-patterned antagonistic race relations, an interstitial socio-cultural political and geographic linkage to both Caribbean drug trafficking routes and the United States and kinship solidarities combine to position poor Puerto Rican neighborhoods as commercial distribution centers for high quality, low cost Colombian heroin. Quantitative analysis shows that heroin markets in cities with highly segregated Puerto Rican communities were more quickly saturated with Colombian-sourced heroin. The level of Hispanic segregation (specifically in cities with a high level of Puerto Rican segregation) had a significant negative association with heroin price from 1990 to 2000. By contrast, there is no correlation between African-American segregation and Colombian-sourced heroin prevalence or price. Our iterative mixed methods dialogue allows for the development and testing of complex social science hypotheses and reduces the limitations specific to each method used in isolation. We build on prior research that assumes geographic proximity to source countries is the most important factor in determining illicit drug prices and purity, while we find more complex, potentially modifiable determinants of geographic variation in retail drug markets. We show that specific patterns of ethnic segregation, racism, poverty and the political economy of socio-cultural survival strategies combined to facilitate the entry of pure, inexpensive Colombian-sourced heroin. Copyright © 2013 Elsevier B.V. All rights reserved.

Sex segregation in undergraduate engineering majors

NASA Astrophysics Data System (ADS)

Litzler, Elizabeth

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 education, I explore gender stratification within one field: engineering. This dissertation investigates why some engineering disciplines have a greater representation of women than other engineering disciplines. I assess the individual and institutional factors and conditions associated with women's representation in certain engineering departments and compare the mechanisms affecting women's and men's choice of majors. I use national data from the Engineering Workforce Commission, survey data from 21 schools in the Project to Assess Climate in Engineering study, and Carnegie Foundation classification information to study sex segregation in engineering majors from multiple perspectives: the individual, major, institution, and country. I utilize correlations, t-tests, cross-tabulations, log-linear modeling, multilevel logistic regression and weighted least squares regression to test the relative utility of alternative explanations for women's disproportionate representation across engineering majors. As a whole, the analyses illustrate the importance of context and environment for women's representation in engineering majors. Hypotheses regarding hostile climate and discrimination find wide support across different analyses, suggesting that women's under-representation in certain engineering majors is not a question of choice or ability. However, individual level factors such as having engineering coursework prior to college show an especially strong association with student choice of major. Overall, the analyses indicate that institutions matter, albeit less for women, and women's under-representation in engineering is not reducible to individual choice. This dissertation provides a broad, descriptive view of the state of sex segregation in engineering as well as a careful analysis of how individual and institutional factors inhibit or encourage sex segregation. This study contributes to the research literature through the use of novel data, testing of occupational segregation theories, and the use of multiple levels of analysis. The analyses provide new insight into an enduring phenomenon, and suggest new avenues for understanding sex segregation in higher education.

Urban segregation and the US heroin market: A quantitative model of anthropological hypotheses from an inner-city drug market

PubMed Central

Castrillo, Fernando Montero; Bourgois, Philippe; Mars, Sarah; Karandinos, George; Unick, Jay; Ciccarone, Daniel

2014-01-01

Background We hypothesize that the location of highly segregated Hispanic and in particular Puerto Rican neighborhoods can explain how Colombian-sourced heroin, which is associated with a large-scale decade long decline in heroin price and increase in purity, was able to enter and proliferate in the US. Methods Our multidisciplinary analysis quantitatively operationalizes participant-observation ethnographic hypotheses informed by social science theory addressing complex political economic, historical, cultural and social processes. First, we ethnographically document the intersection of structural forces shaping Philadelphia's hypersegregated Puerto Rican community as a regional epicenter of the US heroin market. Second, we estimate the relationship between segregation and: a) the entry of Colombian heroin into the US, and b) the retail price per pure gram of heroin in 21 Metropolitan Statistical Areas. Results Ethnographic evidence documents how poverty, historically-patterned antagonistic race relations, an interstitial socio-cultural political and geographic linkage to both Caribbean drug trafficking routes and the United States and kinship solidarities combine to position poor Puerto Rican neighborhoods as commercial distribution centers for high quality, low cost Colombian heroin. Quantitative analysis shows that heroin markets in cities with highly segregated Puerto Rican communities were more quickly saturated with Colombian-sourced heroin. The level of Hispanic segregation (specifically in cities with a high level of Puerto Rican segregation) had a significant negative association with heroin price from 1990–2000. By contrast, there is no correlation between African-American segregation and Colombian-sourced heroin prevalence or price. Discussion Our iterative mixed methods dialogue allows for the development and testing of complex social science hypotheses and reduces the limitations specific to each method used in isolation. We build on prior research that assumes geographic proximity to source countries is the most important factor in determining illicit drug prices and purity, while we find more complex, potentially modifiable determinants of geographic variation in retail drug markets. We show that specific patterns of ethnic segregation, racism, poverty and the political economy of socio-cultural survival strategies combined to facilitate the entry of pure, inexpensive Colombian-sourced heroin. PMID:24445118

Segregation by onset asynchrony.

PubMed

Hancock, P J B; Walton, L; Mitchell, G; Plenderleith, Y; Phillips, W A

2008-08-05

We describe a simple psychophysical paradigm for studying figure-ground segregation by onset asynchrony. Two pseudorandom arrays of Gabor patches are displayed, to left and right of fixation. Within one array, a subset of elements form a figure, such as a randomly curving path, that can only be reliably detected when their onset is not synchronized with that of the background elements. Several findings are reported. First, for most participants, segregation required an onset asynchrony of 20-40 ms. Second, detection was no better when the figure was presented first, and thus by itself, than when the background elements were presented first, even though in the latter case the figure could not be detected in either of the two successive displays alone. Third, asynchrony segregated subsets of randomly oriented elements equally well. Fourth, asynchronous onsets aligned with the path could be discriminated from those lying on the path but not aligned with it. Fifth, both transient and sustained neural activity contribute to detection. We argue that these findings are compatible with neural signaling by synchronized rate codes. Finally, schizophrenic disorganization is associated with reduced sensitivity. Thus, in addition to bearing upon basic theoretical issues, this paradigm may have clinical utility.

Evaluating Student Satisfaction with Blended Learning in a Gender-Segregated Environment

ERIC Educational Resources Information Center

Naaj, Mahmoud Abou; Nachouki, Mirna; Ankit, Ahmed

2012-01-01

Blended learning combines multiple delivery media that are designed to complement each other and promote learning and application-learned behavior (Smith & Dillon, 1999). This article reports on a study conducted in the College of Information Technology to evaluate levels of student' satisfaction with blended learning. The particular blend of…

Vocational Teachers' Gendered Reflections on Education, Teaching and Care

ERIC Educational Resources Information Center

Lahelma, Elina; Lappalainen, Sirpa; Palmu, Tarja; Pehkonen, Leila

2014-01-01

In this article, we discuss teachers' reflections on the relation between teaching and care in the two most gender-segregated sectors of vocational upper secondary education in Finland, namely Health and Social services and Transport and Technology. We first discuss the concepts around education, teaching, taking care for and caring about…

The Nature of Discourse as Students Collaborate on a Mathematics WebQuest

ERIC Educational Resources Information Center

Orme, Michelle P.; Monroe, Eula Ewing

2005-01-01

Students were audio taped while working in teams on a WebQuest. Although gender-segregated, each team included both fifth- and sixth-graders. Interactions from two tasks were analyzed according to categories (exploratory, cumulative, disputational, tutorial) defined by the Spoken Language and New Technology (SLANT) project (e.g., Wegerif &…

Backlash, Backwater, or Back to the Drawing Board: Feminist Thinking and Librarianship in the 1990s.

ERIC Educational Resources Information Center

Pritchard, Sarah

1994-01-01

Discusses the feminist perspective of librarianship, including following key issues: salaries, pay equity, and occupational segregation; faculty status, professional education, and recruitment; access to information; technology; and sociology of the workplace. A number of myths relating to this topic are addressed, and a bibliography of 18 recent…

On the Alternate Stirring Mode of F-EMS for Bloom Continuous Castings

NASA Astrophysics Data System (ADS)

Sun, Haibo; Li, Liejun; Ye, Dexin; Wu, Xuexing

2018-05-01

Local solute transportation behaviors under different alternate stirring parameters of final electromagnetic stirring (F-EMS) and their influences on the internal quality of the as-cast bloom are compared and evaluated based on a developed coupled model of electromagnetism, heat, and solute transport. To this end, plant trials were conducted in Shaoguan Steel, China. Under the action of F-EMS, a negative segregation band in an ellipse shape is observed at the central area of strand cross section, where the minimum carbon segregation degree is decreased from 0.98 to 0.84 as the stirring duration increases from 15 to 35 seconds in the alternate stirring mode, while it is reduced to 0.805 in the continuous stirring mode. The white band and shrinkage cavity are simultaneously observed at strand center under the conditions of continuous stirring mode, and alternate stirring mode with a stirring period of 35 seconds because of the local over-sustaining melt rotation. In contrast, the V-shape porosity belt width and strand center segregation fluctuation range increase from 60 to 90 mm and from 0.12 to 0.30, respectively, as the stirring duration is reduced from 25 to 15 seconds in the alternate stirring mode because of the poor mixing of the local melt at the strand center.

TMAP/CKAP2 is essential for proper chromosome segregation.

PubMed

Hong, Kyung Uk; Kim, Eunhee; Bae, Chang-Dae; Park, Joobae

2009-01-15

Tumor-associated microtubule-associated protein (TMAP), also known as cytoskeleton associated protein 2 (CKAP2), is a novel mitotic spindle-associated protein which is frequently up-regulated in various malignances. However, its cellular functions remain unknown. Previous reports suggested that the cellular functions of TMAP/CKAP2 pertain to regulation of the dynamics and assembly of the mitotic spindle. To investigate its role in mitosis, we studied the effects of siRNA-mediated depletion of TMAP/CKAP2 in cultured mammalian cells. Unexpectedly, TMAP/CKAP2 knockdown did not result in significant alterations of the spindle apparatus. However, TMAP/CKAP2-depleted cells often exhibited abnormal nuclear morphologies, which were accompanied by abnormal organization of the nuclear lamina, and chromatin bridge formation between two daughter cell nuclei. Time lapse video microscopy revealed that the changes in nuclear morphology and chromatin bridge formations observed in TMAP/CKAP2-depleted cells are the result of defects in chromosome segregation. Consistent with this, the spindle checkpoint activity was significantly reduced in TMAP/CKAP2-depleted cells. Moreover, chromosome missegregation induced by depletion of TMAP/CKAP2 ultimately resulted in reduced cell viability and increased chromosomal instability. Our present findings demonstrate that TMAP/CKAP2 is essential for proper chromosome segregation and for maintaining genomic stability.

Identification of segregated regions in the functional brain connectome of autistic patients by a combination of fuzzy spectral clustering and entropy analysis

PubMed Central

Sato, João Ricardo; Balardin, Joana; Vidal, Maciel Calebe; Fujita, André

2016-01-01

Background Several neuroimaging studies support the model of abnormal development of brain connectivity in patients with autism-spectrum disorders (ASD). In this study, we aimed to test the hypothesis of reduced functional network segregation in autistic patients compared with controls. Methods Functional MRI data from children acquired under a resting-state protocol (Autism Brain Imaging Data Exchange [ABIDE]) were submitted to both fuzzy spectral clustering (FSC) with entropy analysis and graph modularity analysis. Results We included data from 814 children in our analysis. We identified 5 regions of interest comprising the motor, temporal and occipito-temporal cortices with increased entropy (p < 0.05) in the clustering structure (i.e., more segregation in the controls). Moreover, we noticed a statistically reduced modularity (p < 0.001) in the autistic patients compared with the controls. Significantly reduced eigenvector centrality values (p < 0.05) in the patients were observed in the same regions that were identified in the FSC analysis. Limitations There is considerable heterogeneity in the fMRI acquisition protocols among the sites that contributed to the ABIDE data set (e.g., scanner type, pulse sequence, duration of scan and resting-state protocol). Moreover, the sites differed in many variables related to sample characterization (e.g., age, IQ and ASD diagnostic criteria). Therefore, we cannot rule out the possibility that additional differences in functional network organization would be found in a more homogeneous data sample of individuals with ASD. Conclusion Our results suggest that the organization of the whole-brain functional network in patients with ASD is different from that observed in controls, which implies a reduced modularity of the brain functional networks involved in sensorimotor, social, affective and cognitive processing. PMID:26505141

Achieving Continuous Manufacturing for Final Dosage Formation: Challenges and How to Meet Them May 20-21 2014 Continuous Manufacturing Symposium.

PubMed

Byrn, Stephen; Futran, Maricio; Thomas, Hayden; Jayjock, Eric; Maron, Nicola; Meyer, Robert F; Myerson, Allan S; Thien, Michael P; Trout, Bernhardt L

2015-03-01

We describe the key issues and possibilities for continuous final dosage formation, otherwise known as downstream processing or drug product manufacturing. A distinction is made between heterogeneous processing and homogeneous processing, the latter of which is expected to add more value to continuous manufacturing. We also give the key motivations for moving to continuous manufacturing, some of the exciting new technologies, and the barriers to implementation of continuous manufacturing. Continuous processing of heterogeneous blends is the natural first step in converting existing batch processes to continuous. In heterogeneous processing, there are discrete particles that can segregate, versus in homogeneous processing, components are blended and homogenized such that they do not segregate. Heterogeneous processing can incorporate technologies that are closer to existing technologies, where homogeneous processing necessitates the development and incorporation of new technologies. Homogeneous processing has the greatest potential for reaping the full rewards of continuous manufacturing, but it takes long-term vision and a more significant change in process development than heterogeneous processing. Heterogeneous processing has the detriment that, as the technologies are adopted rather than developed, there is a strong tendency to incorporate correction steps, what we call below "The Rube Goldberg Problem." Thus, although heterogeneous processing will likely play a major role in the near-term transformation of heterogeneous to continuous processing, it is expected that homogeneous processing is the next step that will follow. Specific action items for industry leaders are. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Numerical Analysis of the Effect of Particle Shape and Adhesion on the Segregation of Powder Mixtures

NASA Astrophysics Data System (ADS)

Alizadeh Behjani, Mohammadreza; Hassanpour, Ali; Ghadiri, Mojtaba; Bayly, Andrew

2017-06-01

Segregation of granules is an undesired phenomenon in which particles in a mixture separate from each other based on the differences in their physical and chemical properties. It is, therefore, crucial to control the homogeneity of the system by applying appropriate techniques. This requires a fundamental understanding of the underlying mechanisms. In this study, the effect of particle shape and cohesion has been analysed. As a model system prone to segregation, a ternary mixture of particles representing the common ingredients of home washing powders, namely, spray dried detergent powders, tetraacetylethylenediamine, and enzyme placebo (as the minor ingredient) during heap formation is modelled numerically by the Discrete Element Method (DEM) with an aim to investigate the effect of cohesion/adhesion of the minor components on segregation quality. Non-spherical particle shapes are created in DEM using the clumped-sphere method based on their X-ray tomograms. Experimentally, inter particle adhesion is generated by coating the minor ingredient (enzyme placebo) with Polyethylene Glycol 400 (PEG 400). The JKR theory is used to model the cohesion/adhesion of coated enzyme placebo particles in the simulation. Tests are carried out experimentally and simulated numerically by mixing the placebo particles (uncoated and coated) with the other ingredients and pouring them in a test box. The simulation and experimental results are compared qualitatively and quantitatively. It is found that coating the minor ingredient in the mixture reduces segregation significantly while the change in flowability of the system is negligible.

QTL examination of a bi-parental mapping population segregating for “short-stature” in hop (Humulus lupulus L.)

USDA-ARS?s Scientific Manuscript database

Increasing labor costs and reduced labor pools for hop production have resulted in the necessity to develop strategies to improve efficiency and automate hop production and harvest. One solution for reducing labor inputs is the use and production of “low-trellis” hop varieties optimized for mechani...

GaAsBi/GaAs multi-quantum well LED grown by molecular beam epitaxy using a two-substrate-temperature technique.

PubMed

Patil, Pallavi Kisan; Luna, Esperanza; Matsuda, Teruyoshi; Yamada, Kohki; Kamiya, Keisuke; Ishikawa, Fumitaro; Shimomura, Satoshi

2017-03-10

We report a GaAs 0.96 Bi 0.04 /GaAs multiple quantum well (MQW) light emitting diode (LED) grown by molecular beam epitaxy using a two-substrate-temperature (TST) technique. In particular, the QWs and the barriers in the intrinsic region were grown at the different temperatures of [Formula: see text] = 350 °C and [Formula: see text] respectively. Investigations of the microstructure using transmission electron microscopy (TEM) reveal homogeneous MQWs free of extended defects. Furthermore, the local determination of the Bi distribution profile across the MQWs region using TEM techniques confirm the uniform Bi distribution, while revealing a slightly chemically graded GaAs-on-GaAsBi interface due to Bi surface segregation. Despite this small broadening, we found that Bi segregation is significantly reduced (up to 18% reduction) compared to previous reports on Bi segregation in GaAsBi/GaAs MQWs. Hence, the TST procedure proves as a very efficient method to reduce Bi segregation and thus increase the quality of the layers and interfaces. These improvements positively reflect in the optical properties. Room temperature photoluminescence and electroluminescence (EL) at 1.23 μm emission wavelength are successfully demonstrated using TST MQWs containing less Bi content than in previous reports. Finally, LED fabricated using the present TST technique show current-voltage (I-V) curves with a forward voltage of 3.3 V at an injection current of 130 mA under 1.0 kA cm -2 current excitation. These results not only demonstrate that TST technique provides optical device quality GaAsBi/GaAs MQWs but highlight the relevance of TST-based growth techniques on the fabrication of future heterostructure devices based on dilute bismides.

GaAsBi/GaAs multi-quantum well LED grown by molecular beam epitaxy using a two-substrate-temperature technique

NASA Astrophysics Data System (ADS)

Kisan Patil, Pallavi; Luna, Esperanza; Matsuda, Teruyoshi; Yamada, Kohki; Kamiya, Keisuke; Ishikawa, Fumitaro; Shimomura, Satoshi

2017-03-01

We report a GaAs0.96Bi0.04/GaAs multiple quantum well (MQW) light emitting diode (LED) grown by molecular beam epitaxy using a two-substrate-temperature (TST) technique. In particular, the QWs and the barriers in the intrinsic region were grown at the different temperatures of {T}{{GaAsBi}} = 350 °C and {T}{{GaAs}} = 550 ^\\circ {{C}}, respectively. Investigations of the microstructure using transmission electron microscopy (TEM) reveal homogeneous MQWs free of extended defects. Furthermore, the local determination of the Bi distribution profile across the MQWs region using TEM techniques confirm the uniform Bi distribution, while revealing a slightly chemically graded GaAs-on-GaAsBi interface due to Bi surface segregation. Despite this small broadening, we found that Bi segregation is significantly reduced (up to 18% reduction) compared to previous reports on Bi segregation in GaAsBi/GaAs MQWs. Hence, the TST procedure proves as a very efficient method to reduce Bi segregation and thus increase the quality of the layers and interfaces. These improvements positively reflect in the optical properties. Room temperature photoluminescence and electroluminescence (EL) at 1.23 μm emission wavelength are successfully demonstrated using TST MQWs containing less Bi content than in previous reports. Finally, LED fabricated using the present TST technique show current-voltage (I-V) curves with a forward voltage of 3.3 V at an injection current of 130 mA under 1.0 kA cm-2 current excitation. These results not only demonstrate that TST technique provides optical device quality GaAsBi/GaAs MQWs but highlight the relevance of TST-based growth techniques on the fabrication of future heterostructure devices based on dilute bismides.

Companion Chip: Building a Segregated Hardware Architecture

NASA Astrophysics Data System (ADS)

Pareaud, Thomas; Houelle, Alain; Vaucher, Niolas; Albinet, Mathieu; Honvault, Christophe

2011-08-01

Partitioning is a more and more mature concept in Space industry. It aims at assuring that some error propagation modes are not possible. This paper gives an overview of an analysis conducted in the frame of a research and technology study performed in 2010/2011. The "Java Companion Chip" study addresses an interesting approach to partitioning using hardware concepts: a SoC architecture integrates a master processor, a companion chip and additional hardware functions aiming at enforcing the time and space segregation between the master processor and the slave one.This paper discusses the benefits and the main challenges of the proposed approach. In addition, it presents an application of these concepts to a case study: a Leon/Java processor architecture able to concurrently execute native and Java applications.

Identification of an EMS-induced causal mutation in a gene required for boron-mediated root development by low-coverage genome re-sequencing in Arabidopsis

PubMed Central

Tabata, Ryo; Kamiya, Takehiro; Shigenobu, Shuji; Yamaguchi, Katsushi; Yamada, Masashi; Hasebe, Mitsuyasu; Fujiwara, Toru; Sawa, Shinichiro

2013-01-01

Next-generation sequencing (NGS) technologies enable the rapid production of an enormous quantity of sequence data. These powerful new technologies allow the identification of mutations by whole-genome sequencing. However, most reported NGS-based mapping methods, which are based on bulked segregant analysis, are costly and laborious. To address these limitations, we designed a versatile NGS-based mapping method that consists of a combination of low- to medium-coverage multiplex SOLiD (Sequencing by Oligonucleotide Ligation and Detection) and classical genetic rough mapping. Using only low to medium coverage reduces the SOLiD sequencing costs and, since just 10 to 20 mutant F2 plants are required for rough mapping, the operation is simple enough to handle in a laboratory with limited space and funding. As a proof of principle, we successfully applied this method to identify the CTR1, which is involved in boron-mediated root development, from among a population of high boron requiring Arabidopsis thaliana mutants. Our work demonstrates that this NGS-based mapping method is a moderately priced and versatile method that can readily be applied to other model organisms. PMID:23104114

Curriculum Transformation in a Post-Apartheid South African University: The Arts Faculty, Tshwane University of Technology

ERIC Educational Resources Information Center

Ebewo, Patrick J.; Sirayi, Mzo

2018-01-01

During the apartheid rule in South Africa, established universities and other tertiary institutions were forcibly segregated to serve particular racial groups. Some critics have stated that the apartheid regime in South Africa supported an exclusively Western model of education, and that university education was based on a mono-cultural approach…

Ultrathin, wafer-scale hexagonal boron nitride on dielectric surfaces by diffusion and segregation mechanism

NASA Astrophysics Data System (ADS)

Sonde, Sushant; Dolocan, Andrei; Lu, Ning; Corbet, Chris; Kim, Moon J.; Tutuc, Emanuel; Banerjee, Sanjay K.; Colombo, Luigi

2017-06-01

Chemical vapor deposition (CVD) of two-dimensional (2D) hexagonal boron nitride (h-BN) is at the center of numerous studies for its applications in novel electronic devices. However, a clear understanding of the growth mechanism is lacking for its wider industrial adoption on technologically relevant substrates such as SiO2. Here, we demonstrate a controllable growth method of thin, wafer scale h-BN films on arbitrary substrates. We also clarify the growth mechanism to be diffusion and surface segregation (D-SS) of boron (B) and nitrogen (N) in Ni and Co thin films on SiO2/Si substrates after exposure to diborane and ammonia precursors at high temperature. The segregation was found to be independent of the cooling rates employed in this report, and to our knowledge has not been found nor reported for 2D h-BN growth so far, and thus provides an important direction for controlled growth of h-BN. This unique segregation behavior is a result of a combined effect of high diffusivity, small film thickness and the inability to achieve extremely high cooling rates in CVD systems. The resulting D-SS h-BN films exhibit excellent electrical insulating behavior with an optical bandgap of about 5.8 eV. Moreover, graphene-on-h-BN field effect transistors using the as-grown D-SS h-BN films show a mobility of about 6000 cm2 V-1 s-1 at room temperature.

Reduced Structural Connectivity in Frontostriatal White Matter Tracts in the Associative Loop in Schizophrenia.

PubMed

Levitt, James J; Nestor, Paul G; Levin, Laura; Pelavin, Paula; Lin, Pan; Kubicki, Marek; McCarley, Robert W; Shenton, Martha E; Rathi, Yogesh

2017-11-01

The striatum receives segregated and integrative white matter tracts from the cortex facilitating information processing in the cortico-basal ganglia network. The authors examined both types of input tracts in the striatal associative loop in chronic schizophrenia patients and healthy control subjects. Structural and diffusion MRI scans were acquired on a 3-T system from 26 chronic schizophrenia patients and 26 matched healthy control subjects. Using FreeSurfer, the associative cortex was parcellated into ventrolateral prefrontal cortex and dorsolateral prefrontal cortex subregions. The striatum was manually parcellated into its associative and sensorimotor functional subregions. Fractional anisotropy and normalized streamlines, an estimate of fiber counts, were assessed in four frontostriatal tracts (dorsolateral prefrontal cortex-associative striatum, dorsolateral prefrontal cortex-sensorimotor striatum, ventrolateral prefrontal cortex-associative striatum, and ventrolateral prefrontal cortex-sensorimotor striatum). Furthermore, these measures were correlated with a measure of cognitive control, the Trail-Making Test, Part B. Results showed reduced fractional anisotropy and fewer streamlines in chronic schizophrenia patients for all four tracts, both segregated and integrative. Post hoc t tests showed reduced fractional anisotropy in the left ventrolateral prefrontal cortex-associative striatum and left ventrolateral prefrontal cortex-sensorimotor striatum and fewer normalized streamlines in the right dorsolateral prefrontal cortex-sensorimotor striatum and in the left and right ventrolateral prefrontal cortex-sensorimotor striatum in chronic schizophrenia patients. Furthermore, normalized streamlines in the right dorsolateral prefrontal cortex-sensorimotor striatum negatively correlated with Trail-Making Test, Part B, time spent in healthy control subjects but not in chronic schizophrenia patients. These findings demonstrated that structural connectivity is reduced in both segregated and integrative tracts in the striatal associative loop in chronic schizophrenia and that reduced normalized streamlines in the right-hemisphere dorsolateral prefrontal cortex-sensorimotor striatum predicted worse cognitive control in healthy control subjects but not in chronic schizophrenia patients, suggesting a loss of a "normal" brain-behavior correlation in chronic schizophrenia.

The intriguing complexity of parthenogenesis inheritance in Pilosella rubra (Asteraceae, Lactuceae).

PubMed

Rosenbaumová, Radka; Krahulcová, Anna; Krahulec, František

2012-09-01

Neither the genetic basis nor the inheritance of apomixis is fully understood in plants. The present study is focused on the inheritance of parthenogenesis, one of the basic elements of apomixis, in Pilosella (Asteraceae). A complex pattern of inheritance was recorded in the segregating F(1) progeny recovered from reciprocal crosses between the facultatively apomictic hexaploid P. rubra and the sexual tetraploid P. officinarum. Although both female and male reduced gametes of P. rubra transmitted parthenogenesis at the same rate in the reciprocal crosses, the resulting segregating F(1) progeny inherited parthenogenesis at different rates. The actual transmission rates of parthenogenesis were significantly correlated with the mode of origin of the respective F(1) progeny class. The inheritance of parthenogenesis was significantly reduced in F(1) n + n hybrid progeny from the cross where parthenogenesis was transmitted by female gametes. In F(1) n + 0 polyhaploid progeny from the same cross, however, the transmission rate of parthenogenesis was high; all fertile polyhaploids were parthenogenetic. It appeared that reduced female gametes transmitting parthenogenesis preferentially developed parthenogenetically and only rarely were fertilized in P. rubra. The fact that the determinant for parthenogenesis acts gametophytically in Pilosella and the precocious embryogenesis in parthenogenesis-transmitting megagametophytes was suggested as the most probable explanations for this observation. Furthermore, we observed the different expression of complete apomixis in the non-segregating F(1) 2n + n hybrids as compared to their apomictic maternal parent P. rubra. We suggest that this difference is a result of unspecified interactions between the parental genomes.

The effect of unsteadiness on the time-mean thermal loads in a turbine stage

NASA Technical Reports Server (NTRS)

Kirtley, K. R.; Celestina, M. L.; Adamczyk, J. J.

1993-01-01

Two steady numerical analysis methods and one unsteady method are used to study the viscous three-dimensional flow in the middle stage of the Pratt & Whitney alternate design Space Shuttle Main Engine fuel turbine. The principal characteristic of this flow is that the secondary flows generated in the rotor blade reconfigure a radial inlet total temperature distortion into one with a pitchwise exit hot streak distortion. Secondary flows in the following vane redistribute the radial variation while unsteadiness causes a segregation of hot and cold flow from the hot streak within the vane. Such redistribution and segregation can lead to unexpected thermal loads and reduced durability. The physical phenomena and the ability of a steady analysis to capture them are investigated by performing a numerical experiment whereby the results of the two steady analysis methods are compared to the time-mean of the unsteady simulation. The flow physics related to the segregation and mixing of total temperature are discussed.

A SHORT SEQUENCE IMMEDIATELY UPSTREAM OF THE INTERNAL REPEAT ELEMENTS IS CRITICAL FOR KSHV LANA MEDIATED DNA REPLICATION AND IMPACTS EPISOME PERSISTENCE

PubMed Central

León Vázquez, Erika De; Juillard, Franceline; Rosner, Bernard; Kaye, Kenneth M.

2013-01-01

Kaposi’s sarcoma-associated herpesvirus LANA (1162 residues) mediates episomal persistence of viral genomes during latency. LANA mediates viral DNA replication and segregates episomes to daughter nuclei. A 59 residue deletion immediately upstream of the internal repeat elements rendered LANA highly deficient for DNA replication and modestly deficient for the ability to segregate episomes, while smaller deletions did not. The 59 amino acid deletion reduced LANA episome persistence by ~14-fold, while sequentially smaller deletions resulted in ~3-fold, or no deficiency. Three distinct LANA regions reorganized heterochromatin, one of which contains the deleted sequence, but the deletion did not abolish LANA’s ability to alter chromatin. Therefore, this work identifies a short internal LANA sequence that is critical for DNA replication, has modest effects on episome segregation, and substantially impacts episome persistence; this region may exert its effects through an interacting host cell protein(s). PMID:24314665

nomalous Interface and Surface Strontium Segregation in (La 1-ySr y) 2CoO 4 /La 1-xSr xCoO 3- Heterostructured Thin Films

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

Feng, Zhenxing; Yacoby, Yuzhak; Gadre, Milind

2014-01-01

Heterostructured materials have shown unusual physiochemical properties at the interfaces such as two dimensional electron gas systems, high-temperature superconductivity, and enhanced catalysis. Here we report the first atomic-scale evidence of the microscopic structure of a perovskite/Ruddlesden-Popper heterostructure (having La1-xSrxCoO3- /(La1-ySry)2CoO4 ), and anomalous strontium segregation at the interface and in the Ruddlesden-Popper structure using direct X-ray methods combined with ab initio calculations. The remarkably enhanced activity of such heterostructured surfaces relative to bulk perovskite and Ruddlesden-Popper oxides previously shown for oxygen electrocatalysis at elevated temperatures can be attributed to reduced thermodynamic penalty of oxygen vacancies in the oxide structure associatedmore » with Sr segregation observed in the heterostructure. Our findings provide insights for the design of highly active catalysts for energy conversion and storage applications.« less

Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings

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

Aikin, Jr., Robert M.

2017-10-04

This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation.more » It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.« less

The Rhetoric of Decentralization

ERIC Educational Resources Information Center

Ravitch, Diane

1974-01-01

Questions the rationale for and possible consequences of political decentralization of New York City. Suggests that the disadvantages--reduced level of professionalism, increased expense in multiple government operation, "stabilization" of residential segregation, necessity for budget negotiations because of public disclosure of tax…

An Investigation of Technologies for Hazardous Sludge Reduction at AFLC (Air Force Logistics Command) Industrial Waste Treatment Plants. Volume 2. Literature Review of Available Technologies for Treating Heavy Metal Wastewaters.

DTIC Science & Technology

1983-12-01

plate quality. Dummying of chromium baths is used in the special case where high cathode-to-anode 15ea ratio has resulted in build up of trivalent ... chromium (Cr ).Dummying with a high anode -to-cat hode area ratio can be used to reoxidize the trivalent to hexavalent chromium (Cr +6 ). Proper...the trivalent state, which then can be precipitated as chromium hydroxide by alkali neutralization " Cyanide oxidation (if needed) of segregated

Income inequality and income segregation.

PubMed

Reardon, Sean F; Bischoff, Kendra

2011-01-01

This article investigates how the growth in income inequality from 1970 to 2000 affected patterns of income segregation along three dimensions: the spatial segregation of poverty and affluence, race-specific patterns of income segregation, and the geographic scale of income segregation. The evidence reveals a robust relationship between income inequality and income segregation, an effect that is larger for black families than for white families. In addition, income inequality affects income segregation primarily through its effect on the large-scale spatial segregation of affluence rather than by affecting the spatial segregation of poverty or by altering small-scale patterns of income segregation.

Nanoscopic analysis of oxygen segregation at tilt boundaries in silicon ingots using atom probe tomography combined with TEM and ab initio calculations.

PubMed

Ohno, Y; Inoue, K; Fujiwara, K; Kutsukake, K; Deura, M; Yonenaga, I; Ebisawa, N; Shimizu, Y; Inoue, K; Nagai, Y; Yoshida, H; Takeda, S; Tanaka, S; Kohyama, M

2017-12-01

We have developed an analytical method to determine the segregation levels on the same tilt boundaries (TBs) at the same nanoscopic location by a joint use of atom probe tomography and scanning transmission electron microscopy, and discussed the mechanism of oxygen segregation at TBs in silicon ingots in terms of bond distortions around the TBs. The three-dimensional distribution of oxygen atoms was determined at the typical small- and large-angle TBs by atom probe tomography with a low impurity detection limit (0.01 at.% on a TB plane) simultaneously with high spatial resolution (about 0.4 nm). The three-dimensional distribution was correlated with the atomic stress around the TBs; the stress at large-angle TBs was estimated by ab initio calculations based on atomic resolution scanning transmission electron microscopy data and that at small-angle TBs were calculated with the elastic theory based on dark-field transmission electron microscopy data. Oxygen atoms would segregate at bond-centred sites under tensile stress above about 2 GPa, so as to attain a more stable bonding network by reducing the local stress. The number of oxygen atoms segregating in a unit TB area N GB (in atoms nm -2 ) was determined to be proportional to both the number of the atomic sites under tensile stress in a unit TB area n bc and the average concentration of oxygen atoms around the TB [O i ] (in at.%) with N GB ∼ 50 n bc [O i ]. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

TOTAL ORE PROCESSING INTEGRATION AND MANAGEMENT

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

Leslie Gertsch; Richard Gertsch

2005-05-16

The lessons learned from ore segregation test No.3 were presented to Minntac Mine personnel during the reporting period. Ore was segregated by A-Factor, with low values going to Step 1/2 and high values going to Step 3. During the test, the mine maintained the best split possible for the given production and location constraints. During the test, Step 1&2 A-Factor was lowered more than Step 3 was raised. All other ore quality changes were not manipulated, but the segregation by A-Factor affected most of the other qualities. Magnetic iron, coarse tails, fine tails, silica, and grind changed in response tomore » the split. Segregation was achieved by adding ore from HIS to the Step 3 blend and lowering the amount of LC 1&2 and somewhat lowering the amount of LC 3&4. Conversely, Step 1&2 received less HIS with a corresponding increase in LC 1&2. The amount of IBC was increased to both Steps about one-third of the way into the test. For about the center half of the test, LC 3&4 was reduced to both Steps. The most noticeable layer changes were, then: an increase in the HIS split; a decrease in the LC 1&2 split; adding IBC to both Steps; and lowering LC 3&4 to both Steps. Statistical analysis of the dataset collected during ordinary, non-segregated operation of the mine and mill is continuing. Graphical analysis of blast patterns according to drill monitor data was slowed by student classwork. It is expected to resume after the semester ends in May.« less

Fine-grained linings of leveed channels facilitate runout of granular flows

USGS Publications Warehouse

Kokelaar, B.P.; Graham, R. L.; Gray, J.M.N.T.; Vallance, James W.

2014-01-01

Catastrophic dense granular flows, such as occur in rock avalanches, debris flows and pyroclastic flows, move as fully shearing mixtures that have approximately 60 vol.% solids and tend to segregate to form coarse-grained fronts and leveed channels. Levees restrict spreading of unconfined flows and form as coarse particles that become concentrated in the top of the flow are transported to the front and then advect to the sides in the flow head. Channels from which most material has drained away down slope are commonly lined with fine-grained deposit, widely thought to remain from the tail of the waning flow. We show how segregation in experimental dense flows of carborundum or sand (300–425 μm) mixed with spherical fine ballotini (150–250 μm), on rough slopes of 27–29°, produces fine-grained channel linings that are deposited with the levees, into which they grade laterally. Maximum runout distance is attained with mixtures containing 30–40% sand, just sufficient to segregate and form levees that are adequately robust to restrict the spreading attributable to the low-friction fines. Resin impregnation and serial sectioning of deliberately arrested experimental flows shows how fines-lined levees form from the flow head; the flows create their own stable ‘conduit’ entirely from the front, which in a geophysical context can play an important mechanistic role in facilitating runout. The flow self-organization ensures that low-friction fines at the base of the segregated channel flow shear over fine-grained substrate in the channel, thus reducing frictional energy losses. We propose that in pyroclastic flows and debris flows, which have considerable mobility attributable to pore-fluid pressures, such fine-grained flow-contact zones form similarly and not only reduce frictional energy losses but also reduce flow–substrate permeability so as to enhance pore-fluid pressure retention. Thus the granular flow self-organization that produces fine-grained channel linings can be an important factor in facilitating long runout of catastrophic geophysical flows on the low slopes (few degrees) of depositional fans and aprons around mountains and volcanoes.

Fine-grained linings of leveed channels facilitate runout of granular flows

NASA Astrophysics Data System (ADS)

Kokelaar, B. P.; Graham, R. L.; Gray, J. M. N. T.; Vallance, J. W.

2014-01-01

Catastrophic dense granular flows, such as occur in rock avalanches, debris flows and pyroclastic flows, move as fully shearing mixtures that have approximately 60 vol.% solids and tend to segregate to form coarse-grained fronts and leveed channels. Levees restrict spreading of unconfined flows and form as coarse particles that become concentrated in the top of the flow are transported to the front and then advect to the sides in the flow head. Channels from which most material has drained away down slope are commonly lined with fine-grained deposit, widely thought to remain from the tail of the waning flow. We show how segregation in experimental dense flows of carborundum or sand (300-425 μm) mixed with spherical fine ballotini (150-250 μm), on rough slopes of 27-29°, produces fine-grained channel linings that are deposited with the levees, into which they grade laterally. Maximum runout distance is attained with mixtures containing 30-40% sand, just sufficient to segregate and form levees that are adequately robust to restrict the spreading attributable to the low-friction fines. Resin impregnation and serial sectioning of deliberately arrested experimental flows shows how fines-lined levees form from the flow head; the flows create their own stable ‘conduit’ entirely from the front, which in a geophysical context can play an important mechanistic role in facilitating runout. The flow self-organization ensures that low-friction fines at the base of the segregated channel flow shear over fine-grained substrate in the channel, thus reducing frictional energy losses. We propose that in pyroclastic flows and debris flows, which have considerable mobility attributable to pore-fluid pressures, such fine-grained flow-contact zones form similarly and not only reduce frictional energy losses but also reduce flow-substrate permeability so as to enhance pore-fluid pressure retention. Thus the granular flow self-organization that produces fine-grained channel linings can be an important factor in facilitating long runout of catastrophic geophysical flows on the low slopes (few degrees) of depositional fans and aprons around mountains and volcanoes.

APC/C Dysfunction Limits Excessive Cancer Chromosomal Instability

PubMed Central

Sansregret, Laurent; López-García, Carlos; Koch, André; McGranahan, Nicholas; Chao, William Chong Hang; Barry, David J.; Rowan, Andrew; Instrell, Rachael; Horswell, Stuart; Way, Michael; Howell, Michael; Singleton, Martin R.; Medema, René H.; Nurse, Paul; Petronczki, Mark; Swanton, Charles

2017-01-01

Intercellular heterogeneity, exacerbated by chromosomal instability (CIN), fosters tumor heterogeneity and drug resistance. However, extreme CIN correlates with improved cancer outcome, suggesting that karyotypic diversity required to adapt to selection pressures might be balanced in tumors against the risk of excessive instability. Here, we used a functional genomics screen, genome editing, and pharmacologic approaches to identify CIN-survival factors in diploid cells. We find partial anaphase-promoting complex/cyclosome (APC/C) dysfunction lengthens mitosis, suppresses pharmacologically induced chromosome segregation errors, and reduces naturally occurring lagging chromosomes in cancer cell lines or following tetraploidization. APC/C impairment caused adaptation to MPS1 inhibitors, revealing a likely resistance mechanism to therapies targeting the spindle assembly checkpoint. Finally, CRISPR-mediated introduction of cancer somatic mutations in the APC/C subunit cancer driver gene CDC27 reduces chromosome segregation errors, whereas reversal of an APC/C subunit nonsense mutation increases CIN. Subtle variations in mitotic duration, determined by APC/C activity, influence the extent of CIN, allowing cancer cells to dynamically optimize fitness during tumor evolution. Significance We report a mechanism whereby cancers balance the evolutionary advantages associated with CIN against the fitness costs caused by excessive genome instability, providing insight into the consequence of CDC27 APC/C subunit driver mutations in cancer. Lengthening of mitosis through APC/C modulation may be a common mechanism of resistance to cancer therapeutics that increase chromosome segregation errors. PMID:28069571

Contextual and Developmental Differences in the Neural Architecture of Cognitive Control.

PubMed

Petrican, Raluca; Grady, Cheryl L

2017-08-09

Because both development and context impact functional brain architecture, the neural connectivity signature of a cognitive or affective predisposition may similarly vary across different ages and circumstances. To test this hypothesis, we investigated the effects of age and cognitive versus social-affective context on the stable and time-varying neural architecture of inhibition, the putative core cognitive control component, in a subsample ( N = 359, 22-36 years, 174 men) of the Human Connectome Project. Among younger individuals, a neural signature of superior inhibition emerged in both stable and dynamic connectivity analyses. Dynamically, a context-free signature emerged as stronger segregation of internal cognition (default mode) and environmentally driven control (salience, cingulo-opercular) systems. A dynamic social-affective context-specific signature was observed most clearly in the visual system. Stable connectivity analyses revealed both context-free (greater default mode segregation) and context-specific (greater frontoparietal segregation for higher cognitive load; greater attentional and environmentally driven control system segregation for greater reward value) signatures of inhibition. Superior inhibition in more mature adulthood was typified by reduced segregation in the default network with increasing reward value and increased ventral attention but reduced cingulo-opercular and subcortical system segregation with increasing cognitive load. Failure to evidence this neural profile after the age of 30 predicted poorer life functioning. Our results suggest that distinguishable neural mechanisms underlie individual differences in cognitive control during different young adult stages and across tasks, thereby underscoring the importance of better understanding the interplay among dispositional, developmental, and contextual factors in shaping adaptive versus maladaptive patterns of thought and behavior. SIGNIFICANCE STATEMENT The brain's functional architecture changes across different contexts and life stages. To test whether the neural signature of a trait similarly varies, we investigated cognitive versus social-affective context effects on the stable and time-varying neural architecture of inhibition during a period of neurobehavioral fine-tuning (age 22-36 years). Younger individuals with superior inhibition showed distinguishable context-free and context-specific neural profiles, evidenced in both static and dynamic connectivity analyses. More mature individuals with superior inhibition evidenced only context-specific profiles, revealed in the static connectivity patterns linked to increased reward or cognitive load. Delayed expression of this profile predicted poorer life functioning. Our results underscore the importance of understanding the interplay among dispositional, developmental, and contextual factors in shaping behavior. Copyright © 2017 the authors 0270-6474/17/377711-16$15.00/0.

Gender Neutralities, Dichotomies and Hidden Inequalities: Analysis of Vocational Teachers' Reflections on Gender in the Profession

ERIC Educational Resources Information Center

Lappalainen, Sirpa; Lahelma, Elina; Pehkonen, Leila; Isopahkala-Bouret, Ulpukka

2012-01-01

This article analyses how Finnish vocational teachers make sense of the meanings of gender in their work. The context of the study consists of the two most gender segregated environments of vocational education: the female-dominated Sector of Health and Social Services and the male-dominated Sector of Technology and Transport. Our analysis draws…

Nanoscale organization in the fluorinated room temperature ionic liquid: Tetraethyl ammonium (trifluoromethanesulfonyl)(nonafluorobutylsulfonyl)imide

NASA Astrophysics Data System (ADS)

Lo Celso, F.; Appetecchi, G. B.; Jafta, C. J.; Gontrani, L.; Canongia Lopes, J. N.; Triolo, A.; Russina, O.

2018-05-01

Fluorinated Room Temperature Ionic Liquids (FRTILs) are a branch of ionic liquids that is the object of growing interest for a wide range of potential applications, due to the synergic combination of specifically ionic features and those properties that stem from fluorous tails. So far limited experimental work exists on the micro- and mesoscopic structural organization in this class of compounds. Such a work is however necessary to fully understand morphological details at atomistic level that would have strong implications in terms of bulk properties. Here we use the synergy between X-ray and neutron scattering together with molecular dynamics simulations to access structural details of a technologically relevant FRTIL that is characterised by an anion bearing a long enough fluorinated tail to develop specific morphological features. In particular, we find the first experimental evidence that in FRTILs bearing an asymmetric bis(perfluoroalkyl)sulfonyl-imide anion, fluorous side chains tend to be spatially segregated into nm-scale spatial heterogeneities. This feature together with the well-established micro-segregation of side alkyl chains in conventional RTILs leads to the concept of triphilic ILs, whose technological applications are yet to be fully developed.

Perspective analysis of tri gate germanium tunneling field-effect transistor with dopant segregation region at source/drain

NASA Astrophysics Data System (ADS)

Liu, Liang-kui; Shi, Cheng; Zhang, Yi-bo; Sun, Lei

2017-04-01

A tri gate Ge-based tunneling field-effect transistor (TFET) has been numerically studied with technology computer aided design (TCAD) tools. Dopant segregated Schottky source/drain is applied to the device structure design (DS-TFET). The characteristics of the DS-TFET are compared and analyzed comprehensively. It is found that the performance of n-channel tri gate DS-TFET with a positive bias is insensitive to the dopant concentration and barrier height at n-type drain, and that the dopant concentration and barrier height at a p-type source considerably affect the device performance. The domination of electron current in the entire BTBT current of this device accounts for this phenomenon and the tri-gate DS-TFET is proved to have a higher performance than its dual-gate counterpart.

Racial residential segregation impacts on low birth weight using improved neighborhood boundary definitions.

PubMed

Grady, Sue C

2010-12-01

Research on local racial residential segregation and health generally utilize census tract boundaries as a proxy from within which to estimate individual exposures. Census tracts however, may not accurately reflect the neighborhood environments in which people live and interact. Census tract geography may also capture non-exchangeable populations in socially stratified cities, impacting statistical assumptions of independence. To address these concerns, this study assessed the impact of racial residential segregation (i.e., racial isolation and racial clusters) on low birth weight (i.e., intrauterine growth retardation (IUGR) and preterm birth) in the Detroit Metropolitan Area using optimized neighborhood boundary definitions. Automated zone-matching (AZM) methodology was applied to redefine neighborhood (zones). Maternal and infant health information was obtained from Michigan's vital statistics birth registry (n=137,965) for the years 2004-2006. Multilevel models were estimated to assess the effect of high racial isolation and high racial clusters on IUGR and preterm birth, controlling for maternal race, single marital status, smoking and area-level poverty. The results from this study showed that high racial isolation had a significant effect on IUGR, while the odds of preterm birth were higher in racially clustered zones. African American mothers were at increased odds of having IUGR or preterm infants than other mothers; however, these disparities reduced in highly segregated zones. The predicted incidence of IUGR across racially isolated zones and census tracts differed indicating a modifiable area unit problem (MAUP). MAUP effects were not observed in models predicting preterm incidence in high racial clusters or IUGR or preterm incidence in high poverty areas, demonstrating the stability-reliability of these estimates. Future research should continue to optimize neighborhood boundary definitions, while assessing the sensitivity of segregation measures to changes in scale, to improve our understanding of segregation impacts on racial disparities in low birth weight. Copyright © 2010 Elsevier Inc. All rights reserved.

How to Be a Male at Different Elevations: Ecology of Intra-Sexual Segregation in the Trawling Bat Myotis daubentonii

PubMed Central

Nardone, Valentina; Cistrone, Luca; Di Salvo, Ivy; Ariano, Alessandro; Migliozzi, Antonello; Allegrini, Claudia; Ancillotto, Leonardo; Fulco, Antonio; Russo, Danilo

2015-01-01

Intra-sexual segregation is a form of social segregation widespread among vertebrates. In the bat Myotis daubentonii, males are disproportionately abundant at higher elevations, while females are restricted to lower altitude. Intra-male segregation is also known to occur yet its ecological and behavioural determinants are unclear. We studied male segregation along a river in Central Italy where we tested the following predictions: 1. Upstream ( > 1000 m a.s.l.) males will rely on scarcer prey; 2. To deal with this limitation and exploit a cooler roosting environment, they will employ more prolonged and deeper torpor than downstream (< 900 m a.s.l.) males; 3. Body condition will be better in downstream males as they forage in more productive areas; 4. To cope with less predictable foraging opportunities, upstream males will use more habitat types. Consistent with our predictions, we found that prey were less common at higher altitudes, where bats exhibited prolonged and deeper torpor. Body condition was better in downstream males than in upstream males but not in all summer months. This result reflected a decrease in downstream males’ body condition over the season, perhaps due to the energy costs of reduced opportunities to use torpor and/or intraspecific competition. Downstream males mainly foraged over selected riparian vegetation whereas upstream males used a greater variety of habitats. One controversial issue is whether upstream males are excluded from lower elevations by resident bats. We tested this by translocating 10 upstream males to a downstream roost: eight returned to the high elevation site in 1-2 nights, two persisted at low altitude but did not roost with resident bats. These results are consistent with the idea of segregation due to competition. Living at high altitude allows for more effective heterothermy and may thus be not detrimental for survival, but by staying at lower altitude males increase proximity to females and potentially benefit from summer mating opportunities. PMID:26230548

Interpopulation hybridization results in widespread viability selection across the genome in Tigriopus californicus

PubMed Central

2011-01-01

Background Genetic interactions within hybrids influence their overall fitness. Understanding the details of these interactions can improve our understanding of speciation. One experimental approach is to investigate deviations from Mendelian expectations (segregation distortion) in the inheritance of mapped genetic markers. In this study, we used the copepod Tigriopus californicus, a species which exhibits high genetic divergence between populations and a general pattern of reduced fitness in F2 interpopulation hybrids. Previous studies have implicated both nuclear-cytoplasmic and nuclear-nuclear interactions in causing this fitness reduction. We identified and mapped population-diagnostic single nucleotide polymorphisms (SNPs) and used these to examine segregation distortion across the genome within F2 hybrids. Results We generated a linkage map which included 45 newly elucidated SNPs and 8 population-diagnostic microsatellites used in previous studies. The map, the first available for the Copepoda, was estimated to cover 75% of the genome and included markers on all 12 T. californicus chromosomes. We observed little segregation distortion in newly hatched F2 hybrid larvae (fewer than 10% of markers at p < 0.05), but strikingly higher distortion in F2 hybrid adult males (45% of markers at p < 0.05). Hence, segregation distortion was primarily caused by selection against particular genetic combinations which acted between hatching and maturity. Distorted markers were not distributed randomly across the genome but clustered on particular chromosomes. In contrast to other studies in this species we found little evidence for cytonuclear coadaptation. Instead, different linkage groups exhibited markedly different patterns of distortion, which appear to have been influenced by nuclear-nuclear epistatic interactions and may also reflect genetic load carried within the parental lines. Conclusion Adult male F2 hybrids between two populations of T. californius exhibit dramatic segregation distortion across the genome. Distorted loci are clustered within specific linkage groups, and the direction of distortion differs between chromosomes. This segregation distortion is due to selection acting between hatching and adulthood. PMID:21639918

The intensity of segregation of the OH-Isoprene reaction -measurements above the amazon rain forest-

NASA Astrophysics Data System (ADS)

Sörgel, Matthias; Berger, Martina; Dlugi, Ralph; Harder, Hartwig; Kesselmeier, Jürgen; Mallik, Chinmay; Marno, Daniel; Tsokankunku, Anywhere; Wolff, Stefan; Yanez-Serrano, Ana-Maria; Zelger, Michael

2017-04-01

Incomplete mixing (segregation) causes reduced reaction rates compared to laboratory values derived for well mixed conditions. The dominant contribution to atmospheric chemistry is given by the most important oxidizing agent, the OH-radical, which is regarded as the detergent of the atmosphere as it reacts with the majority of atmospheric pollutants and therefore accelerates their removal from the atmosphere. Hence, to understand atmospheric self-cleansing, we need to quantify and understand the budgets (sources and sinks) of OH. Budgets are generally derived by measuring mixing ratios of known source molecules (either primary or recycling) and the total sink for OH of which isoprene is an important part in the pristine rain forest. The production and loss terms are calculated by using the measured mixing ratios and the laboratory derived kinetic values. If reactants are not well mixed their actual reaction rates are lower in the atmosphere than in the laboratory. Therefore, segregation might play a substantial role in quantifying and understanding the derived budgets. We measured OH-radicals, isoprene and other species (O3, NOx, HO2, H2O) with high time resolution (1-10 Hz) shortly above a rain forest canopy (41 m above ground level) at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W). The site is characterized by high isoprene (up to 20 ppb) and low NO (50 ppt - 500 ppt). Simultaneous measurements of OH and isoprene with high time resolution (necessary to directly calculate the intensity of segregation) are sparse. To our knowledge this is now the third dataset for OH-isoprene segregation but the first from a tropical rain forest. The results will be compared to modeling results from different environments and the effect of trace gas exchange driven by coherent structures on the intensity of segregation will be evaluated as well.

Housing Discrimination, Residential Racial Segregation, and Colorectal Cancer Survival in Southeastern Wisconsin.

PubMed

Zhou, Yuhong; Bemanian, Amin; Beyer, Kirsten M M

2017-04-01

Background: Residential racial segregation is still neglected in contemporary examinations of racial health disparities, including studies of cancer. Even fewer studies examine the processes by which segregation occurs, such as through housing discrimination. This study aims to examine relationships among housing discrimination, segregation, and colorectal cancer survival in southeastern Wisconsin. Methods: Cancer incidence data were obtained from the Wisconsin Cancer Reporting System for two southeastern Wisconsin metropolitan areas. Two indices of mortgage discrimination were derived from Home Mortgage Disclosure Act data, and a measure of segregation (the location quotient) was calculated from U.S. census data; all predictors were specified at the ZIP Code Tabulation Area level. Cox proportional hazards regression was used to examine associations between mortgage discrimination, segregation, and colorectal cancer survival in southeastern Wisconsin. Results: For all-cause mortality, racial bias in mortgage lending was significantly associated with a greater hazard rate among blacks [HR = 1.37; 95% confidence interval (CI), 1.06-1.76] and among black women (HR = 1.53; 95% CI, 1.06-2.21), but not black men in sex-specific models. No associations were identified for redlining or the location quotient. Additional work is needed to determine whether these findings can be replicated in other geographical settings. Conclusions: Our findings indicate that black women in particular experience poorer colorectal cancer survival in neighborhoods characterized by racial bias in mortgage lending, a measure of institutional racism. These findings are in line with previous studies of breast cancer survival. Impact: Housing discrimination and institutional racism may be important targets for policy change to reduce health disparities, including cancer disparities. Cancer Epidemiol Biomarkers Prev; 26(4); 561-8. ©2017 AACR See all the articles in this CEBP Focus section, "Geospatial Approaches to Cancer Control and Population Sciences." ©2017 American Association for Cancer Research.

Continuous flame aerosol synthesis of carbon-coated nano-LiFePO4 for Li-ion batteries

PubMed Central

Waser, Oliver; Büchel, Robert; Hintennach, Andreas; Novák, Petr; Pratsinis, Sotiris E.

2013-01-01

Core-shell, nanosized LiFePO4-carbon particles were made in one step by scalable flame aerosol technology at 7 g/h. Core LiFePO4 particles were made in an enclosed flame spray pyrolysis (FSP) unit and were coated in-situ downstream by auto thermal carbonization (pyrolysis) of swirl-fed C2H2 in an O2-controlled atmosphere. The formation of acetylene carbon black (ACB) shell was investigated as a function of the process fuel-oxidant equivalence ratio (EQR). The core-shell morphology was obtained at slightly fuel-rich conditions (1.0 < EQR < 1.07) whereas segregated ACB and LiFePO4 particles were formed at fuel-lean conditions (0.8 < EQR < 1). Post-annealing of core-shell particles in reducing environment (5 vol% H2 in argon) at 700 °C for up to 4 hours established phase pure, monocrystalline LiFePO4 with a crystal size of 65 nm and 30 wt% ACB content. Uncoated LiFePO4 or segregated LiFePO4-ACB grew to 250 nm at these conditions. Annealing at 800 °C induced carbothermal reduction of LiFePO4 to Fe2P by ACB shell consumption that resulted in cavities between carbon shell and core LiFePO4 and even slight LiFePO4 crystal growth but better electrochemical performance. The present carbon-coated LiFePO4 showed superior cycle stability and higher rate capability than the benchmark, commercially available LiFePO4. PMID:23407817

Environmental Remediation Activities in Japan Following the Fukushima Dai-ichi Reactor Incident - 12603

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

Lively, J.W.; Kelley, J.L.; Marcial, M.R.

2012-07-01

In March 2011, the Fukushima Dai-ichi reactor power plant was crippled by the Great Pacific earthquake and subsequent tsunami. Much of the focus in the news was on the reactor site itself as the utility company (TEPCO), the Japanese government, and experts from around the world worked to bring the damaged plants into a safe shutdown condition and stem the release of radioactivity to the environment. Most of the radioactivity released was carried out to sea with the prevailing winds. Still, as weather patterns changed and winds shifted, a significant plume of radioactive materials released from the plant deposited inmore » the environment surrounding the plant, contaminating large land areas of the Fukushima Prefecture. The magnitude of the radiological impact to the surrounding environmental is so large that the Japanese government has had to reevaluate the meaning of 'acceptably clean'. In many respects, 'acceptably clean' cannot be a one-size-fits-all standard. The economics costs of such an approach would make impossible what is already an enormous and costly environmental response and remediation task. Thus, the Japanese government has embarked upon an approach that is both situation-specific and reasonably achievable. For example, the determination of acceptably clean for a nursery school or kindergarten play yard may be different from that for a parking lot. The acceptably clean level of residual radioactivity in the surface soil of a rice paddy is different from that in a forested area. The recognized exposure situation (scenario) thus plays a large role in the decision process. While sometimes complicated to grasp or implement, such an approach does prioritize national resources to address environment remediation based upon immediate and significant risks. In addition, the Japanese government is testing means and methods, including advanced or promising technologies, that could be proven to be effective in reducing the amount of radioactivity in the environment beyond a fixed, concentration based limit. Essentially, the definition of acceptably clean includes the concept of reasonably achievable, given the available technology, means and methods, and the cost to implement such. The Japanese government recently issued three technology demonstration contracts expressly designed to test and evaluate the available technologies, means, and methods, which, if implemented, might produce the greatest risk reduction from environmental contamination for the best value. One of the Japanese contract holders, Obayashi JV, has teamed with AMEC to demonstrate the applicability and capabilities of the Orion ScanPlot{sup SM} and ScanSort{sup SM} technologies in radiologically impacted towns both inside and immediately outside the 20 km restricted zone. This presentation provides some unique images and informative insight into the environmental radioactive impacts in and around the exclusion zone. It will provide a look at one element of the Japanese government?s efforts to achieve the greatest risk reduction that is reasonably achievable. The Orion ScanPlot{sup SM} and ScanSort{sup SM} are being used with success on the Japan Town Demonstration Project to assess pre-remedial action contamination levels, document the post-remedial action contamination levels and to precisely measure and segregate excavated soils based on their radioactive content and the prescribed segregation limits (DCS). Initial results suggest that these technologies could provide capabilities to the remedial action efforts that would result in considerable improvements in field data certainty and compliance with remedial objectives while reducing overall costs. (authors)« less

Key issues in controlling air pollutants in Dhaka, Bangladesh

NASA Astrophysics Data System (ADS)

Begum, Bilkis A.; Biswas, Swapan K.; Hopke, Philip K.

2011-12-01

Particulate matter (PM) sampling for both coarse and fine fractions was conducted in a semi-residential site (AECD) in Dhaka from February 2005 to December 2006. The samples were analyzed for mass, black carbon (BC), and elemental compositions. The resulting data set were analyzed for sources by Positive Matrix Factorization (EPA-PMF). From previous studies, it is found that, the air quality became worse in the dry winter period compared to the rainy season because of higher particulate matter concentration in the ambient air. Therefore, seasonal source contributions were determined from seasonally segregated data using EPA-PMF modeling so that further policy interventions can be undertaken to improve air quality. From the source apportionment results, it is observed that vehicular emissions and emission from brick kiln are the major contributors to air pollution in Dhaka especially in the dry seasons, while contribution from emissions from metal smelters increases during rainy seasons. The Government of Bangladesh is considering different interventions to reduce the emissions from those sources by adopting conversion of diesel/petrol vehicles to CNG, increasing traffic speed in the city and by introducing green technologies for brick production. However, in order to reduce the transboundary effect it is necessary to take action regionally.

Baltic Consortium on Promoting Gender Equality in Marine Research Organisations (Baltic Gender)

NASA Astrophysics Data System (ADS)

Kısakürek Ibsen, Başak; Braun, Sarah; Heiskanen, Anna-Stiina; Kutser, Tiit; Stadmark, Johanna; Vaitkevičienė, Viktorija; Waniek, Joanna; Werner, Iris; Matthes, Katja

2017-04-01

Marine Science and Technology has been traditionally a male-dominated research field, with a significant lack of women in leadership positions. However, the whole intellectual capacity of men and women alike are needed to create innovative solutions for the sustainable use of marine resources in the face of major global challenges for the development of the marine environment. The EU-funded project, Baltic Gender (GA No. 710363), responds to this need for creating policies and implementing measures at the institutional level with the aim of harvesting the full human capital for the needs of marine research. The main goal of Baltic Gender is to help reduce gender segregation and gender inequalities in Marine Science and Technology. To this end, eight partner institutions from five countries in the Baltic Sea region (Estonia, Finland, Germany, Lithuania and Sweden) came together for the exchange of institutional practices as well as for the transfer of knowledge from institutions/countries leading in gender equality to those following. Baltic Gender will sow the seeds for long-lasting institutional practices by initiating schemes and strategies that promote gender equality in the partner institutions. These include, for instance: the founding of grass-root networks that support the career advancement of women; creating strategies for better reconciliation of work and family life of women and men; the review and improvement of institutional policies and practices with regard to gender balance, fairness and transparency; development of a method protocol for incorporating gender analysis into research projects or programmes of Marine Science and Technology; initiating gender focused training and mentoring in or across all partner institutions. The project will support the implementation of Gender Equality Plans (GEPs), which consist of a set of actions an institution commits to in order to identify any existing gender bias and to implement strategies to advance gender equality on all levels of the organisation. The implementation of GEPs in the partner organisations will be supported via the collection, standardization and analysis of gender-segregated data as well as the establishment of gender-sensitive indicators. Such data analysis is essential for uncovering trends regarding gender (in)equality and for defining/setting explicit targets, whereas indicators are used (together with qualitative methods) for monitoring progress.

Controlling cation segregation in perovskite-based electrodes for high electro-catalytic activity and durability.

PubMed

Li, Yifeng; Zhang, Wenqiang; Zheng, Yun; Chen, Jing; Yu, Bo; Chen, Yan; Liu, Meilin

2017-10-16

Solid oxide cell (SOC) based energy conversion systems have the potential to become the cleanest and most efficient systems for reversible conversion between electricity and chemical fuels due to their high efficiency, low emission, and excellent fuel flexibility. Broad implementation of this technology is however hindered by the lack of high-performance electrode materials. While many perovskite-based materials have shown remarkable promise as electrodes for SOCs, cation enrichment or segregation near the surface or interfaces is often observed, which greatly impacts not only electrode kinetics but also their durability and operational lifespan. Since the chemical and structural variations associated with surface enrichment or segregation are typically confined to the nanoscale, advanced experimental and computational tools are required to probe the detailed composition, structure, and nanostructure of these near-surface regions in real time with high spatial and temporal resolutions. In this review article, an overview of the recent progress made in this area is presented, highlighting the thermodynamic driving forces, kinetics, and various configurations of surface enrichment and segregation in several widely studied perovskite-based material systems. A profound understanding of the correlation between the surface nanostructure and the electro-catalytic activity and stability of the electrodes is then emphasized, which is vital to achieving the rational design of more efficient SOC electrode materials with excellent durability. Furthermore, the methodology and mechanistic understanding of the surface processes are applicable to other materials systems in a wide range of applications, including thermo-chemical photo-assisted splitting of H 2 O/CO 2 and metal-air batteries.

Race and Space in the 1990s: Changes in the Geographic Scale of Racial Residential Segregation, 1990-2000

PubMed Central

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

2014-01-01

We use newly developed methods of measuring spatial segregation across a range of spatial scales to assess changes in racial residential segregation patterns in the 100 largest U.S. metropolitan areas from 1990 to 2000. Our results point to three notable trends in segregation from 1990 to 2000: 1) Hispanic-white and Asian-white segregation levels increased at both micro- and macro-scales; 2) black-white segregation declined at a micro-scale, but was unchanged at a macro-scale; and 3) for all three racial groups and for almost all metropolitan areas, macro-scale segregation accounted for more of the total metropolitan area segregation in 2000 than in 1990. Our examination of the variation in these trends among the metropolitan areas suggests that Hispanic-white and Asian-white segregation changes have been driven largely by increases in macro-scale segregation resulting from the rapid growth of the Hispanic and Asian populations in central cities. The changes in black-white segregation, in contrast, appear to be driven by the continuation of a 30-year trend in declining micro-segregation, coupled with persistent and largely stable patterns of macro-segregation. PMID:19569292

Greenhouse gas emissions of waste management processes and options: A case study.

PubMed

de la Barrera, Belen; Hooda, Peter S

2016-07-01

Increasing concern about climate change is prompting organisations to mitigate their greenhouse gas emissions. Waste management activities also contribute to greenhouse gas emissions. In the waste management sector, there has been an increasing diversion of waste sent to landfill, with much emphasis on recycling and reuse to prevent emissions. This study evaluates the carbon footprint of the different processes involved in waste management systems, considering the entire waste management stream. Waste management data from the Royal Borough of Kingston upon Thames, London (UK), was used to estimate the carbon footprint for its (Royal Borough of Kingston upon Thames) current source segregation system. Second, modelled full and partial co-mingling scenarios were used to estimate carbon emissions from these proposed waste management approaches. The greenhouse gas emissions from the entire waste management system at Royal Borough of Kingston upon Thames were 12,347 t CO2e for the source-segregated scenario, and 11,907 t CO2e for the partial co-mingled model. These emissions amount to 203.26 kg CO2e t(-1) and 196.02 kg CO2e t(-1) municipal solid waste for source-segregated and partial co-mingled, respectively. The change from a source segregation fleet to a partial co-mingling fleet reduced the emissions, at least partly owing to a change in the number and type of vehicles. © The Author(s) 2016.

The Effect of Hydrogen Annealing and Sulfur Content on the Oxidation Resistance of PWA 1480

NASA Technical Reports Server (NTRS)

Smialek, James L.

1997-01-01

For many decades the dramatic effect of trace amounts of reactive elements on alumina and chromia scale adhesion has been recognized and widely studied. Although various theories have been used to account for such behavior, the connection between scale adhesion and sulfur segregation was initially reported by Smeggil et al. This study found strong surface segregation of sulfur from very low levels in the bulk which could then be curtailed by the addition of reactive elements. It was assumed that the reactive elements, which are strong sulfide formers, acted by getting sulfur in the bulk thus precluding sulfur segregation and weakening of the oxide-metal bond. Subsequent studies confirmed that adhesion could be produced by reducing the sulfur impurity level, without reactive elements. The understanding of this phenomenon has been applied to modern single crystal superalloys, where the addition of Y, although very effective, is problematic. Also problematic is definition of the level of sulfur that is acceptable and below which no further adhesion benefit is reached. Published works have indicated a broad transition defined by various materials and oxidation tests. The present study describes the oxidation behavior of one superalloy (PWA 1480) as a function of various sulfur contents produced by hydrogen annealing for various temperatures, times, and sample thicknesses. The purpose is to define more precisely a criterion for adhesion based on total sulfur reservoir and segregation potential.

Analysis of ABCA4 in mixed Spanish families segregating different retinal dystrophies.

PubMed

Paloma, Eva; Coco, Rosa; Martínez-Mir, Amalia; Vilageliu, Lluïsa; Balcells, Susana; Gonzàlez-Duarte, Roser

2002-12-01

Genotype-phenotype correlations highlighted the function of ABCA4 in retinitis pigmentosa (RP),cone-rod dystrophy (CRD) and Stargardt/Fundus Flavimaculatus disease (STGD/FFM). Initial screening of ABCA4 variants showed a correlation between the type of mutation and the severity of the disease. In the present study we have undertaken mutational and haplotype analysis of ABCA4 in three mixed pedigrees segregating different retinal dystrophies. In family I, we have shown cosegregation of different ABCA4 alleles with CRD (homozygosity for L1940P) and three subtypes of STGD/FFM. The first, a mild form, consisting on fundus flavimaculatus-like distribution of flecks, but good visual acuity and absence of dark choroid, was found to cosegregate with alleles R1097C and F553L; the second, a conventional Stargardt phenotype was associated to alleles L1940P/R1097C and the third, displaying severely reduced visual acuity and dark choroid (named FFM), was associated to L1940P/F553L. In family II, segregating STGD and RP phenotypes, while the involvement of ABCA4 in STGD seems clear this is not the case for RP. Finally, in family III, also segregating STGD and RP, ABCA4 fails to explain either phenotype. Our data highlight the wide allelic heterogeneity involving this gene and support the genetic variability (beyond ABCA4) of mixed STGD/RP pedigrees. Copyright 2002 Wiley-Liss, Inc.

Race, Space, and Cumulative Disadvantage: A Case Study of the Subprime Lending Collapse.

PubMed

Rugh, Jacob S; Albright, Len; Massey, Douglas S

2015-05-01

In this article, we describe how residential segregation and individual racial disparities generate racialized patterns of subprime lending and lead to financial loss among black borrowers in segregated cities. We conceptualize race as a cumulative disadvantage because of its direct and indirect effects on socioeconomic status at the individual and neighborhood levels, with consequences that reverberate across a borrower's life and between generations. Using Baltimore, Maryland as a case study setting, we combine data from reports filed under the Home Mortgage Disclosure Act with additional loan-level data from mortgage-backed securities. We find that race and neighborhood racial segregation are critical factors explaining black disadvantage across successive stages in the process of lending and foreclosure, controlling for differences in borrower credit scores, income, occupancy status, and loan-to-value ratios. We analyze the cumulative cost of predatory lending to black borrowers in terms of reduced disposable income and lost wealth. We find the cost to be substantial. Black borrowers paid an estimated additional 5 to 11 percent in monthly payments and those that completed foreclosure in the sample lost an excess of $2 million in home equity. These costs were magnified in mostly black neighborhoods and in turn heavily concentrated in communities of color. By elucidating the mechanisms that link black segregation to discrimination we demonstrate how processes of cumulative disadvantage continue to undermine black socioeconomic status in the United States today.

Rapid identification of lettuce seed germination mutants by bulked segregant analysis and whole genome sequencing.

PubMed

Huo, Heqiang; Henry, Isabelle M; Coppoolse, Eric R; Verhoef-Post, Miriam; Schut, Johan W; de Rooij, Han; Vogelaar, Aat; Joosen, Ronny V L; Woudenberg, Leo; Comai, Luca; Bradford, Kent J

2016-11-01

Lettuce (Lactuca sativa) seeds exhibit thermoinhibition, or failure to complete germination when imbibed at warm temperatures. Chemical mutagenesis was employed to develop lettuce lines that exhibit germination thermotolerance. Two independent thermotolerant lettuce seed mutant lines, TG01 and TG10, were generated through ethyl methanesulfonate mutagenesis. Genetic and physiological analyses indicated that these two mutations were allelic and recessive. To identify the causal gene(s), we applied bulked segregant analysis by whole genome sequencing. For each mutant, bulked DNA samples of segregating thermotolerant (mutant) seeds were sequenced and analyzed for homozygous single-nucleotide polymorphisms. Two independent candidate mutations were identified at different physical positions in the zeaxanthin epoxidase gene (ABSCISIC ACID DEFICIENT 1/ZEAXANTHIN EPOXIDASE, or ABA1/ZEP) in TG01 and TG10. The mutation in TG01 caused an amino acid replacement, whereas the mutation in TG10 resulted in alternative mRNA splicing. Endogenous abscisic acid contents were reduced in both mutants, and expression of the ABA1 gene from wild-type lettuce under its own promoter fully complemented the TG01 mutant. Conventional genetic mapping confirmed that the causal mutations were located near the ZEP/ABA1 gene, but the bulked segregant whole genome sequencing approach more efficiently identified the specific gene responsible for the phenotype. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Analytical estimates of radial segregation in Bridgman growth from low-level steady and periodic accelerations

NASA Astrophysics Data System (ADS)

Naumann, Robert J.; Baugher, Charles

1992-08-01

Estimates of the convective flows driven by horizontal temperature gradients in the vertical Bridgman configuration are made for dilute systems subject to the low level accelerations typical of the residual accelerations experienced by a spacecraft in low Earth orbit. The estimates are made by solving the Navier-Stokes momentum equation in one dimension. The mass transport equation is then solved in two dimensions using a first-order perturbation method. This approach is valid provided the convective velocities are small compared to the growth velocity which generally requires a reduced gravity environment. If this condition is satisfied, there will be no circulating cells, and hence no convective transport along the vertical axis. However, the variations in the vertical velocity with radius will give rise to radial segregation. The approximate analytical model developed here can predict the degree of radial segregation for a variety of material and processing parameters to an accuracy well within a factor of two as compared against numerical computations of the full set of Navier-Stokes equations for steady accelerations. It has the advantage of providing more insight into the complex interplay of the processing parameters and how they affect the solute distribution in the grown crystal. This could be extremely valuable in the design of low-gravity experiments in which the intent is to control radial segregation. Also, the analysis can be extended to consider transient and periodic accelerations, which is difficult and costly to do numerically. Surprisingly, it was found that the relative radial segregation falls as the inverse cube of the frequency for periodic accelerations whose periods are short compared with the characteristic diffusion time.

Compositional segregation and electrical properties characterization of [001]- and [011]-oriented co-growth Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal

NASA Astrophysics Data System (ADS)

Song, Kexin; Li, Zhenrong; Guo, Haisheng; Xu, Zhuo; Fan, Shiji

2018-04-01

A Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 relaxor ferroelectric single crystal boule of 3 in. diameter was grown using [001]- and [011]-oriented co-growth crystals as seeds by the modified Bridgman method. The as-grown crystal boule was divided into two growth regions [001] and [011]. The composition and the electrical properties of samples of the two regions were characterized in detail along the growth direction in the whole crystal boule. The PT content of [001]-grown samples increased from 27.7 to 36.8 mol. % along the growth direction, especially they are averagely higher about 0.7 mol. % than those of [011]-grown samples at the same growth position. The PMN content of [001]-grown samples decreased from 43.0 to 34.8 mol. %, which is lower than that of the corresponding [011]-grown samples. The compositional segregation behavior along [001] and [011] growth directions was discussed based on the crystal growth theories. Variations in the rhombohedral to tetragonal phase transition temperature (TRT), the piezoelectric properties, the coercive electric field and the remnant polarization of [001] samples were discussed according to changes in compositional segregation and crystal anisotropy. Under the exact same growth conditions, the [011]-grown crystal has a larger composition segregation effect than that of the [001]-grown crystal. This result provides a positive effect on analysing the nature and reducing the effect of compositional segregation.

Deformation of a crystalline olivine aggregate containing two immiscible liquids: Implications for early core-mantle differentiation

NASA Astrophysics Data System (ADS)

Cerantola, V.; Walte, N. P.; Rubie, D. C.

2015-05-01

Deformation-assisted segregation of metallic and sulphidic liquid from a solid peridotitic matrix is a process that may contribute to the early differentiation of small planetesimals into a metallic core and a silicate mantle. Here we present results of an experimental study using a simplified system consisting of a polycrystalline Fo90-olivine matrix containing a small percentage of iron sulphide and a synthetic primitive MORB melt, in order to investigate whether the silicate melt enhances the interconnection and segregation of FeS liquid under deformation conditions at varying strain rates. The experiments have been performed at 2 GPa, 1450 °C and strain rates between 1 ×10-3s-1 to 1 ×10-5s-1. Our results show that the presence of silicate melt actually hinders the migration and segregation of sulphide liquid by reducing its interconnectivity. At low to moderate strain rates the sulphide liquid pockets preserved a roundish shape, showing the liquid behavior is governed mainly by surface tension rather than by differential stress. Even at the highest strain rates, insignificant FeS segregation and interconnection were observed. On the other hand the basaltic melt was very mobile during deformation, accommodating part of the strain, which led to its segregation from the matrix at high bulk strains leaving the sulphide liquid stranded in the olivine matrix. Hence, we conclude that deformation-induced percolation of sulphide liquid does not contribute to the formation of planetary cores after the silicate solidus is overstepped. A possible early deformation enhanced core-mantle differentiation after overstepping the Fe-S solidus is not possible between the initial formation of silicate melt and the formation of a widespread magma ocean.

Field Evaluation of Temperature Differential in HMA Mixtures

DOT National Transportation Integrated Search

2012-05-15

Segregation is a common occurrence in hot mix asphalt (HMA) construction. The two types of : segregation encountered are gradation segregation and thermal segregation. This investigation report : involves mainly thermal segregation, which occurs when...

Multiple loci and genetic interactions involving flowering time genes regulate stem branching among natural variants of Arabidopsis.

PubMed

Huang, Xueqing; Ding, Jia; Effgen, Sigi; Turck, Franziska; Koornneef, Maarten

2013-08-01

Shoot branching is a major determinant of plant architecture. Genetic variants for reduced stem branching in the axils of cauline leaves of Arabidopsis were found in some natural accessions and also at low frequency in the progeny of multiparent crosses. Detailed genetic analysis using segregating populations derived from backcrosses with the parental lines and bulked segregant analysis was used to identify the allelic variation controlling reduced stem branching. Eight quantitative trait loci (QTLs) contributing to natural variation for reduced stem branching were identified (REDUCED STEM BRANCHING 1-8 (RSB1-8)). Genetic analysis showed that RSB6 and RSB7, corresponding to flowering time genes FLOWERING LOCUS C (FLC) and FRIGIDA (FRI), epistatically regulate stem branching. Furthermore, FLOWERING LOCUS T (FT), which corresponds to RSB8 as demonstrated by fine-mapping, transgenic complementation and expression analysis, caused pleiotropic effects not only on flowering time, but, in the specific background of active FRI and FLC alleles, also on the RSB trait. The consequence of allelic variation only expressed in late-flowering genotypes revealed novel and thus far unsuspected roles of several genes well characterized for their roles in flowering time control. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Temperature Dependence Discontinuity in the Stability of Manganese doped Ceria Nanocrystals

DOE PAGES

Wu, Longjia; Dholabhai, Pratik; Uberuaga, Blas P.; ...

2017-01-05

CeO 2 has strong potential for chemical-looping water splitting. It has been shown that manganese doping decreases interface energies of CeO 2, allowing increased stability of high surface areas in this oxygen carrier oxide. The phenomenon is related to the segregation of Mn3+ at interfaces, which causes a measurable decrease in excess energy. Here in the present work, it is shown that, despite the stability of nanocrystals of manganese-doped CeO 2 with relation to undoped CeO 2, the effect is strongly dependent on the oxidation state of manganese, i.e., on the temperature. At temperatures below 800 °C, Mn is inmore » the 3+ valence state, and coarsening is hindered by the reduced interface energetics, showing smaller crystal sizes with increasing Mn content. At temperatures above 800 °C, Mn is reduced to its 2+ valence state, and coarsening is enhanced with increasing Mn content. Atomistic simulations show the segregation of Mn to grain boundaries is relatively insensitive to the charge state of the dopant. However, point defect modeling finds that the reduced state causes a decrease in cation vacancy concentration and an increase in cation interstitials, reducing drag forces for grain boundary mobility and increasing growth rates.« less

A hybrid technique for speech segregation and classification using a sophisticated deep neural network

PubMed Central

Nawaz, Tabassam; Mehmood, Zahid; Rashid, Muhammad; Habib, Hafiz Adnan

2018-01-01

Recent research on speech segregation and music fingerprinting has led to improvements in speech segregation and music identification algorithms. Speech and music segregation generally involves the identification of music followed by speech segregation. However, music segregation becomes a challenging task in the presence of noise. This paper proposes a novel method of speech segregation for unlabelled stationary noisy audio signals using the deep belief network (DBN) model. The proposed method successfully segregates a music signal from noisy audio streams. A recurrent neural network (RNN)-based hidden layer segregation model is applied to remove stationary noise. Dictionary-based fisher algorithms are employed for speech classification. The proposed method is tested on three datasets (TIMIT, MIR-1K, and MusicBrainz), and the results indicate the robustness of proposed method for speech segregation. The qualitative and quantitative analysis carried out on three datasets demonstrate the efficiency of the proposed method compared to the state-of-the-art speech segregation and classification-based methods. PMID:29558485

Variation in chlorophyll content per unit leaf area in spring wheat and implications for selection in segregating material.

PubMed

Hamblin, John; Stefanova, Katia; Angessa, Tefera Tolera

2014-01-01

Reduced levels of leaf chlorophyll content per unit leaf area in crops may be of advantage in the search for higher yields. Possible reasons include better light distribution in the crop canopy and less photochemical damage to leaves absorbing more light energy than required for maximum photosynthesis. Reduced chlorophyll may also reduce the heat load at the top of canopy, reducing water requirements to cool leaves. Chloroplasts are nutrient rich and reducing their number may increase available nutrients for growth and development. To determine whether this hypothesis has any validity in spring wheat requires an understanding of genotypic differences in leaf chlorophyll content per unit area in diverse germplasm. This was measured with a SPAD 502 as SPAD units. The study was conducted in series of environments involving up to 28 genotypes, mainly spring wheat. In general, substantial and repeatable genotypic variation was observed. Consistent SPAD readings were recorded for different sampling positions on leaves, between different leaves on single plant, between different plants of the same genotype, and between different genotypes grown in the same or different environments. Plant nutrition affected SPAD units in nutrient poor environments. Wheat genotypes DBW 10 and Transfer were identified as having consistent and contrasting high and low average SPAD readings of 52 and 32 units, respectively, and a methodology to allow selection in segregating populations has been developed.

Effects of centrifugal acceleration on the flows and segregation in vertical Bridgman crystal growth with steady ampoule rotation

NASA Astrophysics Data System (ADS)

Lan, C. W.

2001-07-01

The effects of centrifugal acceleration on the flows and segregation in vertical Bridgman crystal growth with steady ampoule rotation are investigated through numerical simulation. The numerical model is based on the Boussinesq approximation in a rotating frame, and the fluid flow, heat and mass transfer, and the growth interface are solved simultaneously by a robust finite-volume/Newton method. The growth of gallium-doped germanium (GaGe) in the Grenoble furnace is adopted as an example. The calculated results at small Froude number (Fr<<1) are consistent with the previous prediction (Lan, J. Crystal growth 197 (1999) 983). However, at a high rotation speed or in reduced gravity, where the centrifugal acceleration becomes important (Fr˜1), the results are quite different due to the secondary flow induced. Since the direction of the induced flow is different from that of the buoyancy convection due to the concave interface, the flow damping is more effective than that due to the Coriolis force alone. More importantly, radial segregation can be reversed during the flow transition from one to the other.

Centromeric Barrier Disruption Leads to Mitotic Defects in Schizosaccharomyces pombe

PubMed Central

Gaither, Terilyn L.; Merrett, Stephanie L.; Pun, Matthew J.; Scott, Kristin C.

2014-01-01

Centromeres are cis-acting chromosomal domains that direct kinetochore formation, enabling faithful chromosome segregation and preserving genome stability. The centromeres of most eukaryotic organisms are structurally complex, composed of nonoverlapping, structurally and functionally distinct chromatin subdomains, including the specialized core chromatin that underlies the kinetochore and pericentromeric heterochromatin. The genomic and epigenetic features that specify and preserve the adjacent chromatin subdomains critical to centromere identity are currently unknown. Here we demonstrate that chromatin barriers regulate this process in Schizosaccharomyces pombe. Reduced fitness and mitotic chromosome segregation defects occur in strains that carry exogenous DNA inserted at centromere 1 chromatin barriers. Abnormal phenotypes are accompanied by changes in the structural integrity of both the centromeric core chromatin domain, containing the conserved CENP-ACnp1 protein, and the flanking pericentric heterochromatin domain. Barrier mutant cells can revert to wild-type growth and centromere structure at a high frequency after the spontaneous excision of integrated exogenous DNA. Our results reveal a previously undemonstrated role for chromatin barriers in chromosome segregation and in the prevention of genome instability. PMID:24531725

Segregation for reduction of regulated medical waste in the operating room: a case report

PubMed Central

Shinn, Helen Ki; Kim, Byung-Gun; Yang, Chunwoo; Na, WonJu; Song, Jang-Ho

2017-01-01

One-third of all hospital-regulated medical waste (RMW) comes from the operating room (OR), and it considerably consists of disposable packaging and wrapping materials for the sterilization of surgical instruments. This study sought to identify the amount and type of waste produced by ORs in order to reduce the RMW so as to achieve environmentally-friendly waste management in the OR. We performed an initial waste segregation of 4 total knee replacement arthroplasties (TKRAs) and 1 total hip replacement arthroplasty, and later of 1 extra TKRA, 1 laparoscopic anterior resection of the colon, and 1 pelviscopy (with radical vaginal hysterectomy), performed at our OR. The total mass of non-regulated medical waste (non-RMW) and blue wrap amounted to 30.5 kg (24.9%), and that of RMW to 92.1 kg (75.1%). In the course of the study, we noted that the non-RMW included recyclables, such as papers, plastics, cardboards, and various wrapping materials. The study showed that a reduction in RMW generation can be achieved through the systematic segregation of OR waste. PMID:28184276

Niche separation in flycatcher-like species in the lowland rainforests of Malaysia.

PubMed

Mansor, Mohammad Saiful; Ramli, Rosli

2017-07-01

Niche theory suggests that sympatric species reduce interspecific competition through segregation of shared resources by adopting different attack manoeuvres. However, the fact that flycatcher-like bird species exclusively use the sally manoeuvre may thus challenge this view. We studied the foraging ecology of three flycatcher-like species (i.e. Paradise-flycatcher Terpsiphone sp., Black-naped Monarch Hypothymis azurea, and Rufous-winged Philentoma Philentoma pyrhoptera) in the Krau Wildlife Reserve in central Peninsular Malaysia. We investigated foraging preferences of each bird species and the potential niche partitioning via spatial or behavioural segregation. Foraging substrate was important parameter that effectively divided paradise-flycatcher from Black-naped Monarch and Rufous-winged Philentoma, where monarch and philentoma foraged mainly on live green leaves, while paradise-flycatcher foraged on the air. They also exhibited different foraging height preferences. Paradise-flycatcher, for instance, preferred the highest studied strata, while Black-naped Monarch foraged mostly in lower strata, and Rufous-winged Philentoma made use of the lowest strata. This study indicates that niche segregation occurs among sympatric species through foraging substrate and attack manoeuvres selection. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of modified mold shell on the microstructure and tensile fracture morphology of single-crystal nickel-base superalloy

NASA Astrophysics Data System (ADS)

Xu, Weitai; Zhao, Yutao; Sun, Shaochun; Liu, Manping; Ma, Dexin; Liang, Xiangfeng; Wang, Cunlong; Tao, Ran

2018-04-01

The mold shell used for single-crystal turbine blades preparation was modified from conventional process to fiber reinforcement technology. The wall thickness was decreased by 32.3 percent (pct) than the conventional process. Then these two mold shells were used to produce single crystal samples of nickel-base superalloy in a Bridgman furnace. The local temperature curves were recorded in the process. The results show that the modified mold shell can increase the temperature gradient in the mushy zone than the conventional mold shell. The primary and secondary dendrite arm space were reduced by 8 pct and 12 pct, respectively. Moreover, both the area fraction and mean size of the γ‧/γ eutectic were declined, as well as the dendritic segregation tendency. Therefore it contributed to the lower residual eutectic and micro-porosity in the heat-treated microstructure. Further, fracture surface of the samples made by modified mold shell exhibited smaller facets and more uniform dimples in the size and shape.

Atomic scale study of grain boundary segregation before carbide nucleation in Ni-Cr-Fe Alloys

NASA Astrophysics Data System (ADS)

Li, Hui; Xia, Shuang; Liu, Wenqing; Liu, Tingguang; Zhou, Bangxin

2013-08-01

Three dimensional chemical information concerning grain boundary segregation before carbide nucleation was characterized by atom probe tomography in two Ni-Cr-Fe alloys which were aged at 500 °C for 0.5 h after homogenizing treatment. B, C and Si atoms segregation at grain boundary in Alloy 690 was observed. B, C, N and P atoms segregation at grain boundary in 304 austenitic stainless steel was observed. C atoms co-segregation with Cr atoms at the grain boundaries both in Alloy 690 and 304 austenitic stainless steel was found, and its effect on the carbide nucleation was discussed. The amount of each segregated element at grain boundaries in the two Ni-Cr-Fe alloys were analyzed quantitatively. Comparison of the grain boundary segregation features of the two Ni-Cr-Fe alloys were carried out based on the experimental results. The impurity and solute atoms segregate inhomogeneously in the same grain boundary both in 304 SS and Alloy 690. The grain boundary segregation tendencies (Sav) are B (11.8 ± 1.4) > P (5.4 ± 1.4) > N (4.7 ± 0.3) > C (3.7 ± 0.4) in 304 SS, and B (6.9 ± 0.9) > C (6.7 ± 0.4) > Si (1.5 ± 0.2) in Alloy 690. Cr atoms may co-segregate with C atoms at grain boundaries before carbide nucleation at the grain boundaries both in 304 SS and Alloy 690. Ni atoms generally deplete at grain boundary both in 304 SS and Alloy 690. The literature shows that the Ni atoms may co-segregate with P atoms at grain boundaries [28], but the P atoms segregation do not leads to Ni segregation in the current study. In the current study, Fe atoms may segregate or deplete at grain boundary in Alloy 690. But Fe atoms generally deplete at grain boundary in 304 SS. B atoms have the strongest grain boundary segregation tendency both in 304 SS and Alloy 690. The grain boundary segregation tendency and Gibbs free energy of B in 304 SS is higher than in Alloy 690. C atoms are easy to segregate at grain boundaries both in 304 SS and Alloy 690. The grain boundary segregation tendency and Gibbs free energy of C in Alloy 690 is higher than in 304 SS, due to the higher bulk C concentration and the site competition of P atoms which segregate at grain boundary [29,30]. It is imply that the segregation tendency is influenced by the bulk concentration of the segregates. Si atoms slightly segregate at grain boundaries in Alloy 690, but do not segregate at grain boundaries in 304 SS. N and P atoms segregate at grain boundary in 304 SS, and their segregation Gibbs free energy are similar. N atoms may be exhausted by the TiN precipitated in the matrix and can not be observed in the grain boundary of Alloy 690 [19]. Mn atoms deplete at grain boundary in 304 SS. This phenomenon is similar to that of proton irradiation induced segregation in 304 SS [32]. B, C, N, P segregation Gibbs energies are similar both in 304 SS and Alloy 690. B and C atoms segregate at grain boundary both in Alloy 690 and 304 SS, P and N segregate at grain boundary in 304 SS. Si atoms segregate at grain boundary in Alloy 690, but do not segregate at grain boundary in 304 SS. Cr enriches at grain boundary both in Alloy 690 and 304 SS, although carbide does not nucleate. Ni and Fe may segregate, deplete or homogeneously distribute at grain boundary in Alloy 690, but they deplete at grain boundary in 304 SS. C and Cr atoms co-segregate at grain boundaries before carbide nucleation in Alloy 690 and 304 SS. Combination with other results in literatures, the evolution of Cr concentration at grain boundary should be enrichment at grain boundary before carbide nucleation, depletion at grain boundary after carbide precipitation, and healing after obvious growth of carbide. After aging treatment at 500 °C for 0.5 h, the total reduction of grain boundary free energy due to segregation is 27.489 kJ/mol for Alloy 690 and 45.207 kJ/mol for 304.

Analysis of surface segregation in polymer mixtures: A combination of mean field and statistical associated fluid theories

NASA Astrophysics Data System (ADS)

Krawczyk, Jaroslaw; Croce, Salvatore; Chakrabarti, Buddhapriya; Tasche, Jos

The surface segregation in polymer mixtures remains a challenging problem for both academic exploration as well as industrial applications. Despite its ubiquity and several theoretical attempts a good agreement between computed and experimentally observed profiles has not yet been achieved. A simple theoretical model proposed in this context by Schmidt and Binder combines Flory-Huggins free energy of mixing with the square gradient theory of wetting of a wall by fluid. While the theory gives us a qualitative understanding of the surface induced segregation and the surface enrichment it lacks the quantitative comparison with the experiment. The statistical associating fluid theory (SAFT) allows us to calculate accurate free energy for a real polymeric materials. In an earlier work we had shown that increasing the bulk modulus of a polymer matrix through which small molecules migrate to the free surface causes reduction in the surface migrant fraction using Schmidt-Binder and self-consistent field theories. In this work we validate this idea by combining mean field theories and SAFT to identify parameter ranges where such an effect should be observable. Department of Molecular Physics, Łódź University of Technology, Żeromskiego 116, 90-924 Łódź, Poland.

Stabilization of MgAl 2O 4 spinel surfaces via doping

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

Hasan, Md. M.; Dholabhai, Pratik P.; Castro, Ricardo H. R.

Here, the surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. We report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl 2O 4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y 3+, Gd 3+,more » La 3+) and one tetravalent dopant (Zr 4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.« less

Impurity segregation behavior in polycrystalline silicon ingot grown with variation of electron-beam power

NASA Astrophysics Data System (ADS)

Lee, Jun-Kyu; Lee, Jin-Seok; Jang, Bo-Yun; Kim, Joon-Soo; Ahn, Young-Soo; Cho, Churl-Hee

2014-08-01

Electron beam melting (EBM) systems have been used to improve the purity of metallurgical grade silicon feedstock for photovoltaic application. Our advanced EBM system is able to effectively remove volatile impurities using a heat source with high energy from an electron gun and to continuously allow impurities to segregate at the top of an ingot solidified in a directional solidification (DS) zone in a vacuum chamber. Heat in the silicon melt should move toward the ingot bottom for the desired DS. However, heat flux though the ingot is changed as the ingot becomes longer due to low thermal conductivity of silicon. This causes a non-uniform microstructure of the ingot, finally leading to impurity segregation at its middle. In this research, EB power irradiated on the silicon melt was controlled during the ingot growth in order to suppress the change of heat flux. EB power was reduced from 12 to 6.6 kW during the growth period of 45 min with a drop rate of 0.125 kW/min. Also, the silicon ingot was grown under a constant EB power of 12 kW to estimate the effect of the drop rate of EB power. When the EB power was reduced, the grains with columnar shape were much larger at the middle of the ingot compared to the case of constant EB power. Also, the present research reports a possible reason for the improvement of ingot purity by considering heat flux behaviors.

Stabilization of MgAl2O4 spinel surfaces via doping

NASA Astrophysics Data System (ADS)

Hasan, Md. M.; Dholabhai, Pratik P.; Castro, Ricardo H. R.; Uberuaga, Blas P.

2016-07-01

Surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. Here, we report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl2O4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y3+, Gd3+, La3+) and one tetravalent dopant (Zr4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.

Stabilization of MgAl 2O 4 spinel surfaces via doping

DOE PAGES

Hasan, Md. M.; Dholabhai, Pratik P.; Castro, Ricardo H. R.; ...

2016-02-06

Here, the surface structure of complex oxides plays a vital role in processes such as sintering, thin film growth, and catalysis, as well as being a critical factor determining the stability of nanoparticles. We report atomistic calculations of the low-index stoichiometric magnesium aluminate spinel (MgAl 2O 4) surfaces, each with two different chemical terminations. High temperature annealing was used to explore the potential energy landscape and provide more stable surface structures. We find that the lowest energy surface is {100} while the highest energy surface is {111}. The surfaces were subsequently doped with three trivalent dopants (Y 3+, Gd 3+,more » La 3+) and one tetravalent dopant (Zr 4+) and both the surface segregation energies of the dopants and surface energies of the doped surface were determined. All of the dopants reduce the surface energy of spinel, though this reduction in energy depends on both the size and valence of the dopant. Dopants with larger ionic radius tend to segregate to the surface more strongly and reduce the surface energy to a greater extent. Furthermore, the ionic valence of the dopants seems to have a stronger influence on the segregation than does ionic size. For both undoped and doped spinel, the predicted crystal shape is dominated by {100} surfaces, but the relative fraction of the various surfaces changes with doping due to the unequal changes in energy, which has implications on equilibrium nanoparticle shapes and therefore on applications sensitive to surface properties.« less

Multi-material classification of dry recyclables from municipal solid waste based on thermal imaging.

PubMed

Gundupalli, Sathish Paulraj; Hait, Subrata; Thakur, Atul

2017-12-01

There has been a significant rise in municipal solid waste (MSW) generation in the last few decades due to rapid urbanization and industrialization. Due to the lack of source segregation practice, a need for automated segregation of recyclables from MSW exists in the developing countries. This paper reports a thermal imaging based system for classifying useful recyclables from simulated MSW sample. Experimental results have demonstrated the possibility to use thermal imaging technique for classification and a robotic system for sorting of recyclables in a single process step. The reported classification system yields an accuracy in the range of 85-96% and is comparable with the existing single-material recyclable classification techniques. We believe that the reported thermal imaging based system can emerge as a viable and inexpensive large-scale classification-cum-sorting technology in recycling plants for processing MSW in developing countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Trends in Gender Segregation in the Choice of Science and Engineering Majors*

PubMed Central

Mann, Allison; DiPrete, Thomas A.

2013-01-01

Numerous theories have been put forward for the high and continuing levels of gender segregation in science, technology, engineering, and mathematics (STEM) fields, but research has not systematically examined the extent to which these theories for the gender gap are consistent with actual trends. Using both administrative data and four separate longitudinal studies sponsored by the U.S. Department of Education’s National Center for Education Statistics (NCES), we evaluate several prominent explanations for the persisting gender gap in STEM fields related to mathematics performance and background and general life goals, and find that none of them are empirically satisfactory. Instead, we suggest that the structure of majors and their linkages to professional training and careers may combine with gender differences in educational goals to influence the persisting gender gap in STEM fields. An analysis of gendered career aspirations, course-taking patterns, and pathways to medical and law school supports this explanation. PMID:24090849

Blood cell interactions and segregation in flow.

PubMed

Munn, Lance L; Dupin, Michael M

2008-04-01

For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall.

Interface segregation behavior in thermal aged austenitic precipitation strengthened stainless steel.

PubMed

Li, Hui; Song, Hui; Liu, Wenqing; Xia, Shuang; Zhou, Bangxin; Su, Cheng; Ding, Wenyan

2015-12-01

The segregation of various elements at grain boundaries, precipitate/matrix interfaces were analyzed using atom probe tomography in an austenitic precipitation strengthened stainless steel aged at 750 °C for different time. Segregation of P, B and C at all types of interfaces in all the specimens were observed. However, Si segregated at all types of interfaces only in the specimen aged for 16 h. Enrichment of Ti at grain boundaries was evident in the specimen aged for 16 h, while Ti did not segregate at other interfaces. Mo varied considerably among interface types, e.g. from segregated at grain boundaries in the specimens after all the aging time to never segregate at γ'/γ phase interfaces. Cr co-segregated with C at grain boundaries, although carbides still did not nucleate at grain boundaries yet. Despite segregation tendency variations in different interface types, the segregation tendency evolution variation of different elements depending aging time were analyzed among all types of interfaces. Based on the experimental results, the enrichment factors, Gibbs interface excess and segregation free energies of segregated elements were calculated and discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

The Sex Composition of Selective Colleges and Gender Differences in Career Aspirations.

ERIC Educational Resources Information Center

Bressler, Marvin; Wendell, Peter

1980-01-01

Selective single-sex colleges provide a more favorable environment than comparable coeducational institutions for influencing White, middle-class, academically capable undergraduates of both sexes to disregard conventional occupational prescriptions based on gender. Sexually segregated academic settings are instrumental in reducing male-female…

Quality control/quality assurance testing for joint density and segregation of asphalt mixtures : tech transfer summary.

DOT National Transportation Integrated Search

2013-04-01

A longitudinal joint is the interface between two adjacent and parallel hot-mix asphalt (HMA) mats. Inadequate joint construction can lead to a location where water can penetrate the pavement layers and reduce the structural support of the underlying...

Effective search for stable segregation configurations at grain boundaries with data-mining techniques

NASA Astrophysics Data System (ADS)

Kiyohara, Shin; Mizoguchi, Teruyasu

2018-03-01

Grain boundary segregation of dopants plays a crucial role in materials properties. To investigate the dopant segregation behavior at the grain boundary, an enormous number of combinations have to be considered in the segregation of multiple dopants at the complex grain boundary structures. Here, two data mining techniques, the random-forests regression and the genetic algorithm, were applied to determine stable segregation sites at grain boundaries efficiently. Using the random-forests method, a predictive model was constructed from 2% of the segregation configurations and it has been shown that this model could determine the stable segregation configurations. Furthermore, the genetic algorithm also successfully determined the most stable segregation configuration with great efficiency. We demonstrate that these approaches are quite effective to investigate the dopant segregation behaviors at grain boundaries.

Residential Segregation and Racial Cancer Disparities: A Systematic Review.

PubMed

Landrine, Hope; Corral, Irma; Lee, Joseph G L; Efird, Jimmy T; Hall, Marla B; Bess, Jukelia J

2017-12-01

This paper provides the first review of empirical studies of segregation and black-white cancer disparities. We searched all years of PubMed (through May 2016) using these terms: racial segregation, residential segregation, neighborhood racial composition (first terms) and (second terms) cancer incidence, mortality, survival, stage at diagnosis, screening. The 17 (of 668) articles that measured both segregation and a cancer outcome were retained. Segregation contributed significantly to cancer and to racial cancer disparities in 70% of analyses, even after controlling for socioeconomic status and health insurance. Residing in segregated African-American areas was associated with higher odds of later-stage diagnosis of breast and lung cancers, higher mortality rates and lower survival rates from breast and lung cancers, and higher cumulative cancer risks associated with exposure to ambient air toxics. There were no studies of many types of cancer (e.g., cervical). Studies differed in their measure of segregation, and 40% used an invalid measure. Possible mediators of the segregation effect usually were not tested. Empirical analysis of segregation and racial cancer disparities is a recent area of research. The literature is limited to 17 studies that focused primarily on breast cancer. Studies differed in their measure of segregation, yet segregation nonetheless contributed to cancer and to racial cancer disparities in 70% of analyses. This suggests the need for further research that uses valid measures of segregation, examines a variety of types of cancers, and explores the variables that may mediate the segregation effect.

49 CFR 176.80 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Segregation Requirements § 176.80 Applicability. (a) This subpart sets forth segregation requirements in addition to any segregation requirements set forth elsewhere in this subchapter. (b) Hazardous materials in... segregation requirements of this subpart and any additional segregation specified in this subchapter for...

49 CFR 176.80 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Segregation Requirements § 176.80 Applicability. (a) This subpart sets forth segregation requirements in addition to any segregation requirements set forth elsewhere in this subchapter. (b) Hazardous materials in... segregation requirements of this subpart and any additional segregation specified in this subchapter for...

The New Segregation.

ERIC Educational Resources Information Center

Laosa, Luis M.

2001-01-01

This issue reviews national demographic trends in school segregation, summarizing research findings. Though the national debate on school segregation emphasizes blacks and whites, present-day school segregation includes segregation by socioeconomic level, ethnicity, and native language. The research study examined features of the ecology of…

Site-preference and valency for rare-earth sites in (R-Ce)2Fe14B magnets

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

Alam, Aftab; Khan, Mahmud; McCallum, R. W.

2013-01-28

Rare-earth (R) permanent magnets of R2Fe14B have technological importance due to their high energy products, and they have two R-sites (Wyckoff 4f and 4g, with four-fold multiplicity) that affect chemistry and valence. Designing magnetic behavior and stability via alloying is technologically relevant to reduce critical (expensive) R-content while retaining key properties; cerium, an abundant (cheap) R-element, offers this potential. We calculate magnetic properties and Ce site preference in (R1-xCex)2Fe14B [R=La,Nd] using density functional theory (DFT) methods—including a DFT+U scheme to treat localized 4f-electrons. Fe moments compare well with neutron data—almost unaffected by Hubbard U, and weakly affected by spin-orbit coupling.more » In La2Fe14B, Ce alloys for 0 ≤ x ≤ 1 and prefers smaller R(4f) sites, as observed, a trend we find unaffected by valence. Whereas, in Nd2Fe14B, Ce is predicted to have limited alloying (x ≤ 0.3) with a preference for larger R(4g) sites, resulting in weak partial ordering and segregation. The Curie temperatures versus x for (Nd,Ce) were predicted for a typical sample processing and verified experimentally.« less

Development of Protection and Control Unit for Distribution Substation

NASA Astrophysics Data System (ADS)

Iguchi, Fumiaki; Hayashi, Hideyuki; Takeuchi, Motohiro; Kido, Mitsuyasu; Kobayashi, Takashi; Yanaoka, Atsushi

The Recently, electronics and IT technologies have been rapidly innovated and have been introduced to power system protection & control system to achieve high reliability, maintainability and more functionality. Concerning the distribution substation application, digital relays have been applied for more than 10 years. Because of a number of electronic devices used for it, product cost becomes higher. Also, products installed during the past high-growth period will be at the end of lifetime and will be replaced. Therefore, replacing market is expected to grow and the reduction of cost is demanded. Considering above mentioned background, second generation digital protection and control unit as a successor is designed to have following concepts. Functional integration based on advanced digital technologies, Ethernet LAN based indoor communication network, cost reduction and downsizing. Pondering above concepts, integration of protection and control function is adopted in contrary to the functional segregation applied to the previous system in order to achieve one-unit concept. Also the adoption of Ethernet LAN for inter-unit communication is objective. This report shows the development of second-generation digital relay for distribution substation, which is equipped with control function and Ethernet LAN by reducing the size of auxiliary transformer unit and the same size as previous product is realized.

Facially Amphipathic Glycopolymers Inhibit Ice Recrystallization.

PubMed

Graham, Ben; Fayter, Alice E R; Houston, Judith E; Evans, Rachel C; Gibson, Matthew I

2018-05-02

Antifreeze glycoproteins (AFGPs) from polar fish are the most potent ice recrystallization (growth) inhibitors known, and synthetic mimics are required for low-temperature applications such as cell cryopreservation. Here we introduce facially amphipathic glycopolymers that mimic the three-dimensional structure of AFGPs. Glycopolymers featuring segregated hydrophilic and hydrophobic faces were prepared by ring-opening metathesis polymerization, and their rigid conformation was confirmed by small-angle neutron scattering. Ice recrystallization inhibition (IRI) activity was reduced when a hydrophilic oxo-ether was installed on the glycan-opposing face, but significant activity was restored by incorporating a hydrophobic dimethylfulvene residue. This biomimetic strategy demonstrates that segregated domains of distinct hydrophilicity/hydrophobicity are a crucial motif to introduce IRI activity, which increases our understanding of the complex ice crystal inhibition processes.

Amide-Catalyzed Phase-Selective Crystallization Reduces Defect Density in Wide-Bandgap Perovskites.

PubMed

Kim, Junghwan; Saidaminov, Makhsud I; Tan, Hairen; Zhao, Yicheng; Kim, Younghoon; Choi, Jongmin; Jo, Jea Woong; Fan, James; Quintero-Bermudez, Rafael; Yang, Zhenyu; Quan, Li Na; Wei, Mingyang; Voznyy, Oleksandr; Sargent, Edward H

2018-03-01

Wide-bandgap (WBG) formamidinium-cesium (FA-Cs) lead iodide-bromide mixed perovskites are promising materials for front cells well-matched with crystalline silicon to form tandem solar cells. They offer avenues to augment the performance of widely deployed commercial solar cells. However, phase instability, high open-circuit voltage (V oc ) deficit, and large hysteresis limit this otherwise promising technology. Here, by controlling the crystallization of FA-Cs WBG perovskite with the aid of a formamide cosolvent, light-induced phase segregation and hysteresis in perovskite solar cells are suppressed. The highly polar solvent additive formamide induces direct formation of the black perovskite phase, bypassing the yellow phases, thereby reducing the density of defects in films. As a result, the optimized WBG perovskite solar cells (PSCs) (E g ≈ 1.75 eV) exhibit a high V oc of 1.23 V, reduced hysteresis, and a power conversion efficiency (PCE) of 17.8%. A PCE of 15.2% on 1.1 cm 2 solar cells, the highest among the reported efficiencies for large-area PSCs having this bandgap is also demonstrated. These perovskites show excellent phase stability and thermal stability, as well as long-term air stability. They maintain ≈95% of their initial PCE after 1300 h of storage in dry air without encapsulation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Capturing the Two Dimensions of Residential Segregation at the Neighborhood Level for Health Research

PubMed Central

Oka, Masayoshi; Wong, David W. S.

2014-01-01

Two conceptual and methodological foundations of segregation studies are that (i) segregation involves more than one group, and (ii) segregation measures need to quantify how different population groups are distributed across space. Therefore, percentage of population belonging to a group is not an appropriate measure of segregation because it does not describe how populations are spread across different areal units or neighborhoods. In principle, evenness and isolation are the two distinct dimensions of segregation that capture the spatial patterns of population groups. To portray people’s daily environment more accurately, segregation measures need to account for the spatial relationships between areal units and to reflect the situations at the neighborhood scale. For these reasons, the use of local spatial entropy-based diversity index (SHi) and local spatial isolation index (Si) to capture the evenness and isolation dimensions of segregation, respectively, are preferable. However, these two local spatial segregation indexes have rarely been incorporated into health research. Rather ineffective and insufficient segregation measures have been used in previous studies. Hence, this paper empirically demonstrates how the two measures can reflect the two distinct dimensions of segregation at the neighborhood level, and argues conceptually and set the stage for their future use to effectively and meaningfully examine the relationships between residential segregation and health. PMID:25202687

Residential segregation, dividing walls and mental health: a population-based record linkage study.

PubMed

Maguire, Aideen; French, Declan; O'Reilly, Dermot

2016-09-01

Neighbourhood segregation has been described as a fundamental determinant of physical health, but literature on its effect on mental health is less clear. While most previous research has relied on conceptualised measures of segregation, Northern Ireland is unique as it contains physical manifestations of segregation in the form of segregation barriers (or 'peacelines') which can be used to accurately identify residential segregation. We used population-wide health record data on over 1.3 million individuals, to analyse the effect of residential segregation, measured by both the formal Dissimilarity Index and by proximity to a segregation barrier, on the likelihood of poor mental health. Using multilevel logistic regression models, we found residential segregation measured by the Dissimilarity Index poses no additional risk to the likelihood of poor mental health after adjustment for area-level deprivation. However, residence in an area segregated by a 'peaceline' increases the likelihood of antidepressant medication by 19% (OR=1.19, 95% CI 1.14 to 1.23) and anxiolytic medication by 39% (OR=1.39, 95% CI 1.32 to 1.48), even after adjustment for gender, age, conurbation, deprivation and crime. Living in an area segregated by a 'peaceline' is detrimental to mental health suggesting segregated areas characterised by a heightened sense of 'other' pose a greater risk to mental health. The difference in results based on segregation measure highlights the importance of choice of measure when studying segregation. 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/

Innovations. Separated by Sex. A Troubled New Jersey Middle School Segregates Girls from Boys.

ERIC Educational Resources Information Center

Richardson, Joanna

1995-01-01

The principal of one urban New Jersey middle school chose to deal with a long history of student behavior and discipline problems by making every class single sex. The change helped curb classroom distractions, reduced discipline problems, and restored a sense of order. (SM)

19 CFR 10.538 - Fungible goods and materials.

Code of Federal Regulations, 2010 CFR

2010-04-01

... THE TREASURY ARTICLES CONDITIONALLY FREE, SUBJECT TO A REDUCED RATE, ETC. United States-Singapore Free... either based on the physical segregation of each fungible good or material or by using an inventory management method. For purposes of this subpart, the term “inventory management method” means: (1) Averaging...

Root traits of a soybean (Glycinemax) recombinant inbred population segregating for flooding tolerance.

USDA-ARS?s Scientific Manuscript database

Soybeans (Glycine max) are known to be sensitive to flooding stress. Flooding at the reproductive stage can reduce soybean yield by 50%. However, recent screening efforts have resulted in the identification of genotypes differing in susceptibility to flooding. The flooding tolerant genotype PI 40810...

Proving the Viability of a School Choice Voucher. Policy Brief

ERIC Educational Resources Information Center

Haller, Scott

2015-01-01

A recent Pioneer Institute report written by Ken Ardon and Cara Stilling Candal, "Modeling Urban Scholarship Vouchers in Massachusetts," explores the viability of a school choice voucher program in the Commonwealth. Nationally, school choice has been shown to improve parent satisfaction and student achievement, reduce racial segregation,…

The Role of Residential Segregation in Contemporary School Segregation

ERIC Educational Resources Information Center

Frankenberg, Erica

2013-01-01

Inaction to address housing segregation in metropolitan areas has resulted in persistently high levels of residential segregation. As the Supreme Court has recently limited school districts' voluntary integration efforts, this article considers the role of residential segregation in maintaining racially isolated schools, namely what is known about…

41 CFR 109-1.5106 - Segregation of personal property.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Segregation of personal...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5106 Segregation of personal...) The segregation of the property would materially hinder the progress of the work (i.e., segregation is...

49 CFR 176.146 - Segregation from non-hazardous materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 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, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 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...

41 CFR 109-1.5106 - Segregation of personal property.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Segregation of personal...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5106 Segregation of personal...) The segregation of the property would materially hinder the progress of the work (i.e., segregation is...

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.

Controlling mixing and segregation in time periodic granular flows

NASA Astrophysics Data System (ADS)

Bhattacharya, Tathagata

Segregation is a major problem for many solids processing industries. Differences in particle size or density can lead to flow-induced segregation. In the present work, we employ the discrete element method (DEM)---one type of particle dynamics (PD) technique---to investigate the mixing and segregation of granular material in some prototypical solid handling devices, such as a rotating drum and chute. In DEM, one calculates the trajectories of individual particles based on Newton's laws of motion by employing suitable contact force models and a collision detection algorithm. Recently, it has been suggested that segregation in particle mixers can be thwarted if the particle flow is inverted at a rate above a critical forcing frequency. Further, it has been hypothesized that, for a rotating drum, the effectiveness of this technique can be linked to the probability distribution of the number of times a particle passes through the flowing layer per rotation of the drum. In the first portion of this work, various configurations of solid mixers are numerically and experimentally studied to investigate the conditions for improved mixing in light of these hypotheses. Besides rotating drums, many studies of granular flow have focused on gravity driven chute flows owing to its practical importance in granular transportation and to the fact that the relative simplicity of this type of flow allows for development and testing of new theories. In this part of the work, we observe the deposition behavior of both mono-sized and polydisperse dry granular materials in an inclined chute flow. The effects of different parameters such as chute angle, particle size, falling height and charge amount on the mass fraction distribution of granular materials after deposition are investigated. The simulation results obtained using DEM are compared with the experimental findings and a high degree of agreement is observed. Tuning of the underlying contact force parameters allows the achievement of realistic results and is used as a means of validating the model against available experimental data. The tuned model is then used to find the critical chute length for segregation based on the hypothesis that segregation can be thwarted if the particle flow is inverted at a rate above a critical forcing frequency. The critical frequency, fcrit, is inversely proportional to the characteristic time of segregation, ts. Mixing is observed instead of segregation when the chute length L < U avgts, where Uavg denotes the average stream-wise flow velocity of the particles. While segregation is often an undesired effect, sometimes separating the components of a particle mixture is the ultimate goal. Rate-based separation processes hold promise as both more environmentally benign as well as less energy intensive when compared to conventional particle separations technologies such as vibrating screens or flotation methods. This approach is based on differences in the kinetic properties of the components of a mixture, such as the velocity of migration or diffusivity. In this portion of the work, two examples of novel rate-based separation devices are demonstrated. The first example involves the study of the dynamics of gravity-driven particles through an array of obstacles. Both discrete element (DEM) simulations and experiments are used to augment the understanding of this device. Dissipative collisions (both between the particles themselves and with the obstacles) give rise to a diffusive motion of particles perpendicular to the flow direction and the differences in diffusion lengths are exploited to separate the particles. The second example employs DEM to analyze a ratchet mechanism where a current of particles can be produced in a direction perpendicular to the energy input. In this setup, a vibrating saw-toothed base is employed to induce different mobility for different types of particles. The effect of operating conditions and design parameters on the separation efficiency are discussed. Keywords: granular flow, particle, mixing, segregation, discrete element method, particle dynamics, tumbler, chute, periodic flow inversion, collisional flow, rate-based separation, ratchet, static separator, dissipative particle dynamics, non-spherical droplet.

Soil Segregation Methods for Reducing Transportation and Disposal Costs - 13544

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

Frothingham, David; Andrews, Shawn; Barker, Michelle

2013-07-01

At Formerly Utilized Sites Remedial Action Program (FUSRAP) sites where the selected alternative for contaminated soil is excavation and off-site disposal, the most significant budget items of the remedial action are the costs for transportation and disposal of soil at an off-site facility. At these sites, the objective is to excavate and dispose of only those soils that exceed derived concentration guideline levels. In situ soil segregation using gross gamma detectors to guide the excavation is often challenging at sites where the soil contamination is overlain by clean soil or where the contaminated soil is located in isolated, subsurface pockets.more » In addition, data gaps are often identified during the alternative evaluation and selection process, resulting in increased uncertainty in the extent of subsurface contamination. In response, the U.S. Army Corps of Engineers, Buffalo District is implementing ex situ soil segregation methods. At the remediated Painesville Site, soils were excavated and fed through a conveyor-belt system, which automatically segregated them into above- and below-cleanup criteria discharge piles utilizing gamma spectroscopy. At the Linde Site and the Shallow Land Disposal Area (SLDA) Site, which are both in the remediation phase, soils are initially segregated during the excavation process using gross gamma detectors and then transported to a pad for confirmatory manual surveying and sampling. At the Linde Site, the ex situ soils are analyzed on the basis of a site-specific method, to establish compliance with beneficial reuse criteria that were developed for the Linde remediation. At the SLDA Site, the ex situ soils are surveyed and sampled based on Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) final status survey guidance to demonstrate compliance with the derived concentration guideline levels. At all three sites, the ex situ soils that meet the site- specific DCGLs are retained on-site and used as backfill material. This paper describes the ex situ soil segregation methods, the considerations of each method, and the estimated cost savings from minimizing the volume of soil requiring transportation and off-site disposal. (authors)« less

Niche dynamics of shorebirds in Delaware Bay: Foraging behavior, habitat choice and migration timing

NASA Astrophysics Data System (ADS)

Novcic, Ivana

2016-08-01

Niche differentiation through resource partitioning is seen as one of the most important mechanisms of diversity maintenance contributing to stable coexistence of different species within communities. In this study, I examined whether four species of migrating shorebirds, dunlins (Calidris alpina), semipalmated sandpipers (Calidris pusilla), least sandpipers (Calidris minutilla) and short-billed dowitchers (Limnodromus griseus), segregate by time of passage, habitat use and foraging behavior at their major stopover in Delaware Bay during spring migration. I tested the prediction that most of the separation between morphologically similar species will be achieved by differential migration timing. Despite the high level of overlap along observed niche dimensions, this study demonstrates a certain level of ecological separation between migrating shorebirds. The results of analyses suggest that differential timing of spring migration might be the most important dimension along which shorebird species segregate while at stopover in Delaware Bay. Besides differences in time of passage, species exhibited differences in habitat use, particularly least sandpipers that foraged in vegetated areas of tidal marshes more frequently than other species, as well as short-billed dowitchers that foraged in deeper water more often than small sandpipers did. Partitioning along foraging techniques was less prominent than segregation along temporal or microhabitat dimensions. Such ranking of niche dimensions emphasizes significance of temporal segregation of migratory species - separation of species by time of passage may reduce the opportunity for interspecific aggressive encounters, which in turn can have positive effects on birds' time and energy budget during stopover period.

Race, Space, and Cumulative Disadvantage: A Case Study of the Subprime Lending Collapse

PubMed Central

Rugh, Jacob S.; Albright, Len; Massey, Douglas S.

2016-01-01

In this article, we describe how residential segregation and individual racial disparities generate racialized patterns of subprime lending and lead to financial loss among black borrowers in segregated cities. We conceptualize race as a cumulative disadvantage because of its direct and indirect effects on socioeconomic status at the individual and neighborhood levels, with consequences that reverberate across a borrower's life and between generations. Using Baltimore, Maryland as a case study setting, we combine data from reports filed under the Home Mortgage Disclosure Act with additional loan-level data from mortgage-backed securities. We find that race and neighborhood racial segregation are critical factors explaining black disadvantage across successive stages in the process of lending and foreclosure, controlling for differences in borrower credit scores, income, occupancy status, and loan-to-value ratios. We analyze the cumulative cost of predatory lending to black borrowers in terms of reduced disposable income and lost wealth. We find the cost to be substantial. Black borrowers paid an estimated additional 5 to 11 percent in monthly payments and those that completed foreclosure in the sample lost an excess of $2 million in home equity. These costs were magnified in mostly black neighborhoods and in turn heavily concentrated in communities of color. By elucidating the mechanisms that link black segregation to discrimination we demonstrate how processes of cumulative disadvantage continue to undermine black socioeconomic status in the United States today. PMID:27478254

Point defects at the ice (0001) surface

PubMed Central

Watkins, Matthew; VandeVondele, Joost; Slater, Ben

2010-01-01

Using density functional theory we investigate whether intrinsic defects in ice surface segregate. We predict that hydronium, hydroxide, and the Bjerrum L- and D-defects are all more stable at the surface. However, the energetic cost to create a D-defect at the surface and migrate it into the bulk crystal is smaller than its bulk formation energy. Absolute and relative segregation energies are sensitive to the surface structure of ice, especially the spatial distribution of protons associated with dangling hydrogen bonds. It is found that the basal plane surface of hexagonal ice increases the bulk concentration of Bjerrum defects, strongly favoring D-defects over L-defects. Dangling protons associated with undercoordinated water molecules are preferentially injected into the crystal bulk as Bjerrum D-defects, leading to a surface dipole that attracts hydronium ions. Aside from the disparity in segregation energies for the Bjerrum defects, we find the interactions between defect species to be very finely balanced; surface segregation energies for hydronium and hydroxide species and trapping energies of these ionic species with Bjerrum defects are equal within the accuracy of our calculations. The mobility of the ionic hydronium and hydroxide species is greatly reduced at the surface in comparison to the bulk due to surface sites with high trapping affinities. We suggest that, in pure ice samples, the surface of ice will have an acidic character due to the presence of hydronium ions. This may be important in understanding the reactivity of ice particulates in the upper atmosphere and at the boundary layer. PMID:20615938

Primary vesicles, vesicle-rich segregation structures and recognition of primary and secondary porosities in lava flows from the Paraná igneous province, southern Brazil

NASA Astrophysics Data System (ADS)

Barreto, Carla Joana S.; de Lima, Evandro F.; Goldberg, Karin

2017-04-01

This study focuses on a volcanic succession of pāhoehoe to rubbly lavas of the Paraná-Etendeka Province exposed in a single road profile in southernmost Brazil. This work provides an integrated approach for examining primary vesicles and vesicle-rich segregation structures at the mesoscopic scale. In addition, this study provides a quantitative analysis of pore types in thin section. We documented distinct distribution patterns of vesicle and vesicle-rich segregation structures according to lava thickness. In compound pāhoehoe lavas, the cooling allows only vesicles (<1 cm size) and pipe vesicles to be frozen into place. In inflated pāhoehoe lavas, vesicles of different sizes are common, including pipe vesicles, and also segregation structures such as proto-cylinders, cylinders, cylinder sheets, vesicle sheets, and pods. In rubbly lavas, only vesicles of varying sizes occur. Gas release from melt caused the formation of primary porosity, while hydrothermal alteration and tectonic fracturing are the main processes that generated secondary porosity. Although several forms of porosity were created in the basaltic lava flows, the precipitation of secondary minerals within the pores has tended to reduce the original porosities. Late-stage fractures could create efficient channel networks for possible hydrocarbon/groundwater migration and entrapment owing to their ability to connect single pores. Quantitative permeability data should be gathered in future studies to confirm the potential of these lavas for store hydrocarbons or groundwater.

A critical review of the bioavailability and impacts of heavy metals in municipal solid waste composts compared to sewage sludge.

PubMed

Smith, Stephen R

2009-01-01

The content, behaviour and significance of heavy metals in composted waste materials is important from two potentially conflicting aspects of environmental legislation in terms of: (a) defining end-of-waste criteria and increasing recycling of composted residuals on land and (b) protecting soil quality by preventing contamination. This review examines the effects of heavy metals in compost and amended soil as a basis for achieving a practical and sustainable balance between these different policy objectives, with particular emphasis on agricultural application. All types of municipal solid waste (MSW) compost contain more heavy metals than the background concentrations present in soil and will increase their contents in amended soil. Total concentrations of heavy metals in source-segregated and greenwaste compost are typically below UK PAS100 limits and mechanical segregated material can also comply with the metal limits in UK PAS100, although this is likely to be more challenging. Zinc and Pb are numerically the elements present in the largest amounts in MSW-compost. Lead is the most limiting element to use of mechanically-segregated compost in domestic gardens, but concentrations are typically below risk-based thresholds that protect human health. Composted residuals derived from MSW and greenwaste have a high affinity for binding heavy metals. There is general consensus in the scientific literature that aerobic composting processes increase the complexation of heavy metals in organic waste residuals, and that metals are strongly bound to the compost matrix and organic matter, limiting their solubility and potential bioavailability in soil. Lead is the most strongly bound element and Ni the weakest, with Zn, Cu and Cd showing intermediate sorption characteristics. The strong metal sorption properties of compost produced from MSW or sewage sludge have important benefits for the remediation of metal contaminated industrial and urban soils. Compost and sewage sludge additions to agricultural and other soils, with background concentrations of heavy metals, raise the soil content and the availability of heavy metals for transfer into crop plants. The availability in soil depends on the nature of the chemical association between a metal with the organic residual and soil matrix, the pH value of the soil, the concentration of the element in the compost and the soil, and the ability of the plant to regulate the uptake of a particular element. There is no evidence of increased metal release into available forms as organic matter degrades in soil once compost applications have ceased. However, there is good experimental evidence demonstrating the reduced bioavailability and crop uptake of metals from composted biosolids compared to other types of sewage sludge. It may therefore be inferred that composting processes overall are likely to contribute to lowering the availability of metals in amended soil compared to other waste biostabilisation techniques. The total metal concentration in compost is important in controlling crop uptake of labile elements, like Zn and Cu, which increases with increasing total content of these elements in compost. Therefore, low metal materials, which include source-segregated and greenwaste composts, are likely to have inherently lower metal availabilities overall, at equivalent metal loading rates to soil, compared to composted residuals with larger metal contents. This is explained because the compost matrix modulates metal availability and materials low in metals have stronger sorption capacity compared to high metal composts. Zinc is the element in sewage sludge-treated agricultural soil identified as the main concern in relation to potential impacts on soil microbial activity and is also the most significant metal in compost with regard to soil fertility and microbial processes. However, with the exception of one study, there is no other tangible evidence demonstrating negative impacts of heavy metals applied to soil in compost on soil microbial processes and only positive effects of compost application on the microbial status and fertility of soil are reported. The negative impacts on soil microorganisms apparent in one long-term field experiment could be explained by the exceptionally high concentrations of Cd and other elements in the applied compost, and of Cd in the compost-amended soil, which are unrepresentative of current practice and compost quality. The metal contents of source-segregated MSW or greenwaste compost are smaller compared to mechanically-sorted MSW-compost and sewage sludge, and low metal materials also have the smallest potential metal availabilities. Composting processes also inherently reduce metal availability compared to other organic waste stabilisation methods. Therefore, risks to the environment, human health, crop quality and yield, and soil fertility, from heavy metals in source-segregated MSW or greenwaste-compost are minimal. Furthermore, composts produced from mechanically-segregated MSW generally contain fewer metals than sewage sludge used as an agricultural soil improver under controlled conditions. Consequently, the metal content of mechanically-segregated MSW-compost does not represent a barrier to end-use of the product. The application of appropriate preprocessing and refinement technologies is recommended to minimise the contamination of mechanically-segregated MSW-compost as far as practicable. In conclusion, the scientific evidence indicates that conservative, but pragmatic limits on heavy metals in compost may be set to encourage recycling of composted residuals and contaminant reduction measures, which at the same time, also protect the soil and environment from potentially negative impacts caused by long-term accumulation of heavy metals in soil.

Controlling for Prior Attainment Reduces the Positive Influence that Single-Gender Classroom Initiatives Exert on High School Students' Scholastic Achievements.

PubMed

Pennington, Charlotte R; Kaye, Linda K; Qureshi, Adam W; Heim, Derek

2018-01-01

Research points to the positive impact that gender-segregated schooling and classroom initiatives exert on academic attainment. An evaluation of these studies which reveal positive effects highlights, however, that students are typically selectively assigned to single- or mixed-gender instructional settings, presenting a methodological confound. The current study controls for students' prior attainment to appraise the efficacy of a single-gender classroom initiative implemented in a co-educational high school in the United Kingdom. Secondary data analysis (using archived data) was performed on 266 middle-ability, 11-12 year-old students' standardized test scores in Languages (English, foreign language), STEM-related (Mathematics, Science, Information and Communication Technology), and Non-STEM subjects (art, music, drama). Ninety-eight students (54, 55% female) were taught in single-gender and 168 (69, 41% female) in mixed-gender classrooms. Students undertook identical tests irrespective of classroom type, which were graded in accordance with U.K national curriculum guidelines. Controlling for students' prior attainment, findings indicate that students do not appear to benefit from being taught in single-gender relative to mixed-gender classrooms in Language and STEM-related subjects. Young women benefitted from being taught in mixed-gender relative to single-gender classes for Non-STEM subjects. However, when prior ability is not controlled for, the intervention appears to be effective for all school subjects, highlighting the confounding influence of selective admissions. These findings suggest that gender-segregated classroom initiatives may not bolster students' grades. It is argued that studies that do not control for selection effects may tell us little about the effectiveness of such interventions on scholastic achievement.

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

Centrifugal Sieve for Gravity-Level-Independent Size Segregation of Granular Materials

NASA Technical Reports Server (NTRS)

Walton, Otis R.; Dreyer, Christopher; Riedel, Edward

2013-01-01

Conventional size segregation or screening in batch mode, using stacked vibrated screens, is often a time-consuming process. Utilization of centrifugal force instead of gravity as the primary body force can significantly shorten the time to segregate feedstock into a set of different-sized fractions. Likewise, under reduced gravity or microgravity, a centrifugal sieve system would function as well as it does terrestrially. When vibratory and mechanical blade sieving screens designed for terrestrial conditions were tested under lunar gravity conditions, they did not function well. The centrifugal sieving design of this technology overcomes the issues that prevented sieves designed for terrestrial conditions from functioning under reduced gravity. These sieves feature a rotating outer (cylindrical or conical) screen wall, rotating fast enough for the centrifugal forces near the wall to hold granular material against the rotating screen. Conventional centrifugal sieves have a stationary screen and rapidly rotating blades that shear the granular solid near the stationary screen, and effect the sieving process assisted by the airflow inside the unit. The centrifugal sieves of this new design may (or may not) have an inner blade or blades, moving relative to the rotating wall screen. Some continuous flow embodiments would have no inner auger or blades, but achieve axial motion through vibration. In all cases, the shearing action is gentler than conventional centrifugal sieves, which have very high velocity differences between the stationary outer screen and the rapidly rotating blades. The new design does not depend on airflow in the sieving unit, so it will function just as well in vacuum as in air. One advantage of the innovation for batch sieving is that a batch-mode centrifugal sieve may accomplish the same sieving operation in much less time than a conventional stacked set of vibrated screens (which utilize gravity as the primary driving force for size separation). In continuous mode, the centrifugal sieves can provide steady streams of fine and coarse material separated from a mixed feedstock flow stream. The centrifugal sieves can be scaled to any desired size and/or mass flow rate. Thus, they could be made in sizes suitable for small robotic exploratory missions, or for semi-permanent processing of regolith for extraction of volatiles of minerals. An advantage of the continuous-mode system is that it can be made with absolutely no gravity flow components for feeding material into, or for extracting the separated size streams from, the centrifugal sieve. Thus, the system is capable of functioning in a true microgravity environment. Another advantage of the continuous-mode system is that some embodiments of the innovation have no internal blades or vanes, and thus, can be designed to handle a very wide range of feedstock sizes, including occasional very large oversized pieces, without jamming or seizing up.

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

APC/C Dysfunction Limits Excessive Cancer Chromosomal Instability.

PubMed

Sansregret, Laurent; Patterson, James O; Dewhurst, Sally; López-García, Carlos; Koch, André; McGranahan, Nicholas; Chao, William Chong Hang; Barry, David J; Rowan, Andrew; Instrell, Rachael; Horswell, Stuart; Way, Michael; Howell, Michael; Singleton, Martin R; Medema, René H; Nurse, Paul; Petronczki, Mark; Swanton, Charles

2017-02-01

Intercellular heterogeneity, exacerbated by chromosomal instability (CIN), fosters tumor heterogeneity and drug resistance. However, extreme CIN correlates with improved cancer outcome, suggesting that karyotypic diversity required to adapt to selection pressures might be balanced in tumors against the risk of excessive instability. Here, we used a functional genomics screen, genome editing, and pharmacologic approaches to identify CIN-survival factors in diploid cells. We find partial anaphase-promoting complex/cyclosome (APC/C) dysfunction lengthens mitosis, suppresses pharmacologically induced chromosome segregation errors, and reduces naturally occurring lagging chromosomes in cancer cell lines or following tetraploidization. APC/C impairment caused adaptation to MPS1 inhibitors, revealing a likely resistance mechanism to therapies targeting the spindle assembly checkpoint. Finally, CRISPR-mediated introduction of cancer somatic mutations in the APC/C subunit cancer driver gene CDC27 reduces chromosome segregation errors, whereas reversal of an APC/C subunit nonsense mutation increases CIN. Subtle variations in mitotic duration, determined by APC/C activity, influence the extent of CIN, allowing cancer cells to dynamically optimize fitness during tumor evolution. We report a mechanism whereby cancers balance the evolutionary advantages associated with CIN against the fitness costs caused by excessive genome instability, providing insight into the consequence of CDC27 APC/C subunit driver mutations in cancer. Lengthening of mitosis through APC/C modulation may be a common mechanism of resistance to cancer therapeutics that increase chromosome segregation errors. Cancer Discov; 7(2); 218-33. ©2017 AACR.See related commentary by Burkard and Weaver, p. 134This article is highlighted in the In This Issue feature, p. 115. ©2017 American Association for Cancer Research.

Applying Nightingale charts to evaluate the heterogeneity of biomedical waste in a Hospital

PubMed Central

Paiz, Janini Cristina; Bigolin, Marcio; Schneider, Vania Elisabete; Stedile, Nilva Lúcia Rech

2014-01-01

OBJECTIVES: to evaluate the heterogeneity of biomedical waste (BW) using Nightingale charts. METHOD: cross-sectional study consisting of data collection on wastes (direct observation of receptacles, physical characterisation, and gravimetric composition), development of a Management Information System, and creation of statistical charts. RESULTS: the wastes with the greatest degree of heterogeneity are, in order, recyclable, infectious, and organic wastes; chemical waste had the most efficient segregation; Nightingale charts are useful for quick visualisation and systematisation of information on heterogeneity. CONCLUSION: the development of a management information system and the use of Nightingale charts allows for the identification and correction of errors in waste segregation, which increase health risks and contamination by infectious and chemical wastes and reduce the sale and profit from recyclables. PMID:25591088

Effects of Monomer Structure on Their Organization and Polymerization in a Smectic Liquid Crystal

PubMed

Guymon; Hoggan; Clark; Rieker; Walba; Bowman

1997-01-03

Photopolymerizable diacrylate monomers dissolved in fluid-layer smectic A and smectic C liquid crystal (LC) hosts exhibited significant spatial segregation and orientation that depend strongly on monomer structure. Small, flexible monomers such as 1,6-hexanediol diacrylate (HDDA) oriented parallel to the smectic layers and intercalated, whereas rod-shaped mesogen-like monomers such as 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) oriented normal to the smectic layers and collected within them. Such spatial segregation caused by the smectic layering dramatically enhanced photopolymerization rates; for HDDA, termination rates were reduced, whereas for C6M, both the termination and propagation rates were increased. These polymerization precursor structures suggest novel materials-design paradigms for gel LCs and nanophase-separated polymer systems.

TCIRG1 associated Congenital Neutropenia

PubMed Central

Makaryan, Vahagn; Rosenthal, Elisabeth A.; Bolyard, Audrey Anna; Kelley, Merideth L.; Below, Jennifer E.; Bamshad, Michael J.; Bofferding, Kathryn M.; Smith, Joshua D.; Buckingham, Kati; Boxer, Laurence A.; Skokowa, Julia; Welte, Karl; Nickerson, Deborah A.; Jarvik, Gail P.; Dale, David C.

2014-01-01

Severe congenital neutropenia (SCN) is a rare hematopoietic disorder, with estimated incidence of 1 in 200,000 individuals of European descent, many cases of which are inherited in an autosomal dominant pattern. Despite the fact that several causal genes have been identified, the genetic basis for >30% of cases remains unknown. We report a five generation family segregating a novel single nucleotide variant (SNV) in TCIRG1. There is perfect co-segregation of the SNV with congenital neutropenia in this family; all 11 affected, but none of the unaffected, individuals carry this novel SNV. Western blot analysis show reduced levels of TCIRG1 protein in affected individuals, compared to healthy controls. Two unrelated patients with SCN, identified by independent investigators, are heterozygous for different, rare, highly conserved, coding variants in TCIRG1. PMID:24753205

Innovations in the Assay of Un-Segregated Multi-Isotopic Grade TRU Waste Boxes with SuperHENC and FRAM Technology

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

Simpson, A. P.; Barber, S.; Abdurrahman, N. M.

2006-07-01

The Super High Efficiency Neutron Coincidence Counter (SuperHENC) was originally developed by BIL Solutions Inc., Los Alamos National Laboratory (LANL) and Rocky Flats Environmental Technology Site (RFETS) for assay of transuranic (TRU) waste in Standard Waste Boxes (SWB) at Rocky Flats. This mobile system was a key component in the shipment of over 4,000 SWBs to the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. The system was WIPP certified in 2001 and operated at the site for four years. The success of this system, a passive neutron coincidence counter combined with high resolution gamma spectroscopy, led to themore » order of two new units, delivered to Hanford in 2004. Several new challenges were faced at Hanford: For example, the original RFETS system was calibrated for segregated waste streams such that metals, plastics, wet combustibles and dry combustibles were separated by 'Item Description Codes' prior to assay. Furthermore, the RFETS mission of handling only weapons grade plutonium, enabled the original SuperHENC to benefit from the use of known Pu isotopics. Operations at Hanford, as with most other DOE sites, generate un-segregated waste streams, with a wide diversity of Pu isotopics. Consequently, the new SuperHENCs are required to deal with new technical challenges. The neutron system's software and calibration methodology have been modified to encompass these new requirements. In addition, PC-FRAM software has been added to the gamma system, providing a robust isotopic measurement capability. Finally a new software package has been developed that integrates the neutron and gamma data to provide a final assay results and analysis report. The new system's performance has been rigorously tested and validated against WIPP quality requirements. These modifications, together with the mobile platform, make the new SuperHENC far more versatile in handling diverse waste streams and allow for rapid redeployment around the DOE complex. (authors)« less

Intersecting Inequalities: Research to Reduce Inequality for Immigrant-Origin Children and Youth

ERIC Educational Resources Information Center

Suárez-Orozco, Carola; Yoshikawa, Hirokazu; Tseng, Vivian

2015-01-01

As immigration has reached historic numbers in the United States, immigrant children have become an integral part of the national tapestry. While immigration has grown across all post-industrial nations, inequality has risen at a steep rate on a variety of indicators, including income distribution, child poverty, residential segregation, and…

Aggression, segregation and stability in a dominance hierarchy

PubMed Central

Ang, Tzo Zen; Manica, Andrea

2010-01-01

Central to our understanding of social group formation and maintenance is the question of how within-group conflict resolution is achieved in the face of asymmetrical competition over resources and reproduction. A crucial yet implicit assumption of many conflict resolution models dealing with reproductive skew is that subordinates have perfect knowledge of the extent of conflict between themselves and their dominants, enabling behavioural responses on an individual rather than evolutionary scale. However, a mechanism enabling subordinates to accurately assess their relative conflict levels has yet to be empirically demonstrated. Here, we show in the angelfish Centropyge bicolor that the rate of overt mild aggression from dominants to subordinates acts as a signal of increasing rank conflict. The clarity of this signal can be reduced by spatial segregation, causing subordinates to be less able to respond appropriately by regulation of their foraging rates. A reduced signal ultimately leads to a less well-defined dominance hierarchy and destabilization of the social group. Our study suggests that, contrary to previous suggestions, dominant aggression rates play a crucial role as an accurate information signal required for the evolutionary stability of skew models. PMID:20053647

Enhancing and reducing chirality by opposite circularly-polarized light irradiation on crystalline chiral domains consisting of nonchiral photoresponsive W-shaped liquid crystal molecules.

PubMed

Choi, Suk-Won; Takezoe, Hideo

2016-09-28

We found possible chirality enhancement and reduction in chiral domains formed by photoresponsive W-shaped molecules by irradiation with circularly polarized light (CPL). The W-shaped molecules exhibit a unique smectic phase with spontaneously segregated chiral domains, although the molecules are nonchiral. The chirality control was generated in the crystalline phase, which shows chiral segregation as in the upper smectic phase, and the result appeared to be as follows: for a certain chiral domain, right-CPL stimuli enhanced the chirality, while left-CPL stimuli reduced the chirality, and vice versa for another chiral domain. Interestingly, no domain-size change could be observed after CPL irradiation, suggesting some changes in the causes of chirality. In this way, the present system can recognize the handedness of the applied chiral stimuli. In other words, the present material can be used as a sensitive chiral-stimuli-recognizing material and should find invaluable applications, including in chiroptical switches, sensors, and memories as well as in chiral recognition.

TopBP1 is required at mitosis to reduce transmission of DNA damage to G1 daughter cells

PubMed Central

Pedersen, Rune Troelsgaard; Kruse, Thomas; Nilsson, Jakob

2015-01-01

Genome integrity is critically dependent on timely DNA replication and accurate chromosome segregation. Replication stress delays replication into G2/M, which in turn impairs proper chromosome segregation and inflicts DNA damage on the daughter cells. Here we show that TopBP1 forms foci upon mitotic entry. In early mitosis, TopBP1 marks sites of and promotes unscheduled DNA synthesis. Moreover, TopBP1 is required for focus formation of the structure-selective nuclease and scaffold protein SLX4 in mitosis. Persistent TopBP1 foci transition into 53BP1 nuclear bodies (NBs) in G1 and precise temporal depletion of TopBP1 just before mitotic entry induced formation of 53BP1 NBs in the next cell cycle, showing that TopBP1 acts to reduce transmission of DNA damage to G1 daughter cells. Based on these results, we propose that TopBP1 maintains genome integrity in mitosis by controlling chromatin recruitment of SLX4 and by facilitating unscheduled DNA synthesis. PMID:26283799

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...

Reduced integration and improved segregation of functional brain networks in Alzheimer’s disease

NASA Astrophysics Data System (ADS)

Kabbara, A.; Eid, H.; El Falou, W.; Khalil, M.; Wendling, F.; Hassan, M.

2018-04-01

Objective. Emerging evidence shows that cognitive deficits in Alzheimer’s disease (AD) are associated with disruptions in brain functional connectivity. Thus, the identification of alterations in AD functional networks has become a topic of increasing interest. However, to what extent AD induces disruption of the balance of local and global information processing in the human brain remains elusive. The main objective of this study is to explore the dynamic topological changes of AD networks in terms of brain network segregation and integration. Approach. We used electroencephalography (EEG) data recorded from 20 participants (10 AD patients and 10 healthy controls) during resting state. Functional brain networks were reconstructed using EEG source connectivity computed in different frequency bands. Graph theoretical analyses were performed assess differences between both groups. Main results. Results revealed that AD networks, compared to networks of age-matched healthy controls, are characterized by lower global information processing (integration) and higher local information processing (segregation). Results showed also significant correlation between the alterations in the AD patients’ functional brain networks and their cognitive scores. Significance. These findings may contribute to the development of EEG network-based test that could strengthen results obtained from currently-used neurophysiological tests in neurodegenerative diseases.

Investigating niche partitioning of ectomycorrhizal fungi in specialized rooting zones of the monodominant leguminous tree Dicymbe corymbosa.

PubMed

Smith, Matthew E; Henkel, Terry W; Williams, Gwendolyn C; Aime, M Catherine; Fremier, Alexander K; Vilgalys, Rytas

2017-07-01

Temperate ectomycorrhizal (ECM) fungi show segregation whereby some species dominate in organic layers and others favor mineral soils. Weak layering in tropical soils is hypothesized to decrease niche space and therefore reduce the diversity of ectomycorrhizal fungi. The Neotropical ECM tree Dicymbe corymbosa forms monodominant stands and has a distinct physiognomy with vertical crown development, adventitious roots and massive root mounds, leading to multi-stemmed trees with spatially segregated rooting environments: aerial litter caches, aerial decayed wood, organic root mounds and mineral soil. We hypothesized that these microhabitats host distinct fungal assemblages and therefore promote diversity. To test our hypothesis, we sampled D. corymbosa ectomycorrhizal root tips from the four microhabitats and analyzed community composition based on pyrosequencing of fungal internal transcribed spacer (ITS) barcode markers. Several dominant fungi were ubiquitous but analyses nonetheless suggested that communities in mineral soil samples were statistically distinct from communities in organic microhabitats. These data indicate that distinctive rooting zones of D. corymbosa contribute to spatial segregation of the fungal community and likely enhance fungal diversity. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Reduced integration and improved segregation of functional brain networks in Alzheimer's disease.

PubMed

Kabbara, A; Eid, H; El Falou, W; Khalil, M; Wendling, F; Hassan, M

2018-04-01

Emerging evidence shows that cognitive deficits in Alzheimer's disease (AD) are associated with disruptions in brain functional connectivity. Thus, the identification of alterations in AD functional networks has become a topic of increasing interest. However, to what extent AD induces disruption of the balance of local and global information processing in the human brain remains elusive. The main objective of this study is to explore the dynamic topological changes of AD networks in terms of brain network segregation and integration. We used electroencephalography (EEG) data recorded from 20 participants (10 AD patients and 10 healthy controls) during resting state. Functional brain networks were reconstructed using EEG source connectivity computed in different frequency bands. Graph theoretical analyses were performed assess differences between both groups. Results revealed that AD networks, compared to networks of age-matched healthy controls, are characterized by lower global information processing (integration) and higher local information processing (segregation). Results showed also significant correlation between the alterations in the AD patients' functional brain networks and their cognitive scores. These findings may contribute to the development of EEG network-based test that could strengthen results obtained from currently-used neurophysiological tests in neurodegenerative diseases.

Perceptual asymmetry reveals neural substrates underlying stereoscopic transparency.

PubMed

Tsirlin, Inna; Allison, Robert S; Wilcox, Laurie M

2012-02-01

We describe a perceptual asymmetry found in stereoscopic perception of overlaid random-dot surfaces. Specifically, the minimum separation in depth needed to perceptually segregate two overlaid surfaces depended on the distribution of dots across the surfaces. With the total dot density fixed, significantly larger inter-plane disparities were required for perceptual segregation of the surfaces when the front surface had fewer dots than the back surface compared to when the back surface was the one with fewer dots. We propose that our results reflect an asymmetry in the signal strength of the front and back surfaces due to the assignment of the spaces between the dots to the back surface by disparity interpolation. This hypothesis was supported by the results of two experiments designed to reduce the imbalance in the neuronal response to the two surfaces. We modeled the psychophysical data with a network of inter-neural connections: excitatory within-disparity and inhibitory across disparity, where the spread of disparity was modulated according to figure-ground assignment. These psychophysical and computational findings suggest that stereoscopic transparency depends on both inter-neural interactions of disparity-tuned cells and higher-level processes governing figure ground segregation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of Boron Microalloying Element on Susceptibility to Hydrogen Embrittlement in High Strength Mooring Chain Steel

NASA Astrophysics Data System (ADS)

Li, H.; Cheng, X. Y.; Shen, H. P.; Su, L. C.; Zhang, S. Y.

The susceptibility to hydrogen embrittlement in high strength mooring chain steel with different boron content (0, 0.003 %, 0.008 %) were investigated by electrochemical hydrogen charging technique and tensile test. The results revealed that appropriate boron content can effectively depress hydrogen induced embrittlement. Precharged with a low current density, this effect seemed to be unobvious. It gradually became clearly with the increasing current density. The increase of resistance to the hydrogen embrittlement for 3B and 8B after adding appropriate boron was attributed to three facts. The first was that the segregation of boron atoms along grain boundaries reduced the grain boundary segregation of phosphorus, which prohibited hydrogen concentration at the grain boundaries, depressing the possibility of the intergranular fracture due to H. The second was that the segregation of boron increased intergranular cohesion, enhanced grain boundary strength, and refined the final microstructure. The third was that the addition of boron changed the state of hydrogen traps, leading to the small amount of diffusible hydrogen. That is to say, hydrogen transferred to these defects by dislocations was accordingly decreased, which led to the low sensitive of hydrogen induced cracking.

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

The materials processing research base of the Materials Processing Center

NASA Technical Reports Server (NTRS)

Latanision, R. M.

1986-01-01

An annual report of the research activities of the Materials Processing Center of the Massachusetts Institute of Technology is given. Research on dielectrophoresis in the microgravity environment, phase separation kinetics in immiscible liquids, transport properties of droplet clusters in gravity-free fields, probes and monitors for the study of solidification of molten semiconductors, fluid mechanics and mass transfer in melt crystal growth, and heat flow control and segregation in directional solidification are discussed.

Airfield Damage Repair (ADR); Polymer Repair of Airfields Summary of Research

DTIC Science & Technology

2007-12-01

reported in section 4.3.1. Prior to mixing, the stainless steel bowl, paddle and molds were sprayed with an industrial silicone release agent, Zip-Slip...aggressive foaming and segregation problems. airfield damage repair, (ADR), polymer, concrete, polymer concrete, crater repair U U U UU 30 R. Craig...Polymer Technology for Agile Combat Support to develop a rapid crater repair using resin binders for indigenous materials. The research team consisted of

Suppressed Sr segregation and performance of directly assembled La0.6Sr0.4Co0.2Fe0.8O3-δ oxygen electrode on Y2O3-ZrO2 electrolyte of solid oxide electrolysis cells

NASA Astrophysics Data System (ADS)

Ai, Na; He, Shuai; Li, Na; Zhang, Qi; Rickard, William D. A.; Chen, Kongfa; Zhang, Teng; Jiang, San Ping

2018-04-01

Active and stable oxygen electrode is probably the most important in the development of solid oxide electrolysis cells (SOECs) technologies. Herein, we report the successful development of mixed ionic and electronic conducting (MIEC) La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) perovskite oxides directly assembled on barrier-layer-free yttria-stabilized zirconia (YSZ) electrolyte as highly active and stable oxygen electrodes of SOECs. Electrolysis polarization effectively induces the formation of electrode/electrolyte interface, similar to that observed under solid oxide fuel cell (SOFC) operation conditions. However, in contrast to the significant performance decay under SOFC operation conditions, the cell with directly assembled LSCF oxygen electrodes shows excellent stability, tested for 300 h at 0.5 A cm-2 and 750 °C under SOEC operation conditions. Detailed microstructure and phase analysis reveal that Sr segregation is inevitable for LSCF electrode, but anodic polarization substantially suppresses Sr segregation and migration to the electrode/electrolyte interface, leading to the formation of stable and efficient electrode/electrolyte interface for water and CO2 electrolysis under SOECs operation conditions. The present study demonstrates the feasibility of using directly assembled MIEC cobaltite based oxygen electrodes on barrier-layer-free YSZ electrolyte of SOECs.

Staged thermal fractionation for segregation of lignin and cellulose pyrolysis products: An experimental study of residence time and temperature effects

DOE PAGES

Waters, Christopher L.; Janupala, Rajiv R.; Mallinson, Richard G.; ...

2017-05-25

Thermal conversion technologies may be the most efficient means of production of transportation fuels from lignocellulosic biomass. In order to increase the viability and improve the carbon emissions profile of pyrolysis biofuels, improvements must be made to the required catalytic upgrading to increase both hydrogen utilization efficiency and final liquid carbon yields. However, no current single catalytic valorization strategy can be optimized to convert the complex mixture of compounds produced upon fast pyrolysis of biomass. Staged thermal fractionation, which entails a series of sequentially increasing temperature steps to decompose biomass, has been proposed as a simple means to create vapormore » product streams of enhanced purity as compared to fast pyrolysis. In this work, we use analytical pyrolysis to investigate the effects of time and temperature on a thermal step designed to segregate the lignin and cellulose pyrolysis products of a biomass which has been pre-torrefied to remove hemicellulose. At process conditions of 380 °C and 180 s isothermal hold time, a stream containing less than 20% phenolics (carbon basis) was produced, and upon subsequent fast pyrolysis of the residual solid a stream of 81.5% levoglucosan (carbon basis) was produced. The thermal segregation comes at the expense of vapor product carbon yield, but the improvement in catalytic performance may offset these losses.« less

Staged thermal fractionation for segregation of lignin and cellulose pyrolysis products: An experimental study of residence time and temperature effects

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

Waters, Christopher L.; Janupala, Rajiv R.; Mallinson, Richard G.

Thermal conversion technologies may be the most efficient means of production of transportation fuels from lignocellulosic biomass. In order to increase the viability and improve the carbon emissions profile of pyrolysis biofuels, improvements must be made to the required catalytic upgrading to increase both hydrogen utilization efficiency and final liquid carbon yields. However, no current single catalytic valorization strategy can be optimized to convert the complex mixture of compounds produced upon fast pyrolysis of biomass. Staged thermal fractionation, which entails a series of sequentially increasing temperature steps to decompose biomass, has been proposed as a simple means to create vapormore » product streams of enhanced purity as compared to fast pyrolysis. In this work, we use analytical pyrolysis to investigate the effects of time and temperature on a thermal step designed to segregate the lignin and cellulose pyrolysis products of a biomass which has been pre-torrefied to remove hemicellulose. At process conditions of 380 °C and 180 s isothermal hold time, a stream containing less than 20% phenolics (carbon basis) was produced, and upon subsequent fast pyrolysis of the residual solid a stream of 81.5% levoglucosan (carbon basis) was produced. The thermal segregation comes at the expense of vapor product carbon yield, but the improvement in catalytic performance may offset these losses.« less

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.

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)

Ascertainment correction for Markov chain Monte Carlo segregation and linkage analysis of a quantitative trait.

PubMed

Ma, Jianzhong; Amos, Christopher I; Warwick Daw, E

2007-09-01

Although extended pedigrees are often sampled through probands with extreme levels of a quantitative trait, Markov chain Monte Carlo (MCMC) methods for segregation and linkage analysis have not been able to perform ascertainment corrections. Further, the extent to which ascertainment of pedigrees leads to biases in the estimation of segregation and linkage parameters has not been previously studied for MCMC procedures. In this paper, we studied these issues with a Bayesian MCMC approach for joint segregation and linkage analysis, as implemented in the package Loki. We first simulated pedigrees ascertained through individuals with extreme values of a quantitative trait in spirit of the sequential sampling theory of Cannings and Thompson [Cannings and Thompson [1977] Clin. Genet. 12:208-212]. Using our simulated data, we detected no bias in estimates of the trait locus location. However, in addition to allele frequencies, when the ascertainment threshold was higher than or close to the true value of the highest genotypic mean, bias was also found in the estimation of this parameter. When there were multiple trait loci, this bias destroyed the additivity of the effects of the trait loci, and caused biases in the estimation all genotypic means when a purely additive model was used for analyzing the data. To account for pedigree ascertainment with sequential sampling, we developed a Bayesian ascertainment approach and implemented Metropolis-Hastings updates in the MCMC samplers used in Loki. Ascertainment correction greatly reduced biases in parameter estimates. Our method is designed for multiple, but a fixed number of trait loci. Copyright (c) 2007 Wiley-Liss, Inc.

Growth model and structure evolution of Ag layers deposited on Ge films.

PubMed

Ciesielski, Arkadiusz; Skowronski, Lukasz; Górecka, Ewa; Kierdaszuk, Jakub; Szoplik, Tomasz

2018-01-01

We investigated the crystallinity and optical parameters of silver layers of 10-35 nm thickness as a function 2-10 nm thick Ge wetting films deposited on SiO 2 substrates. X-ray reflectometry (XRR) and X-ray diffraction (XRD) measurements proved that segregation of germanium into the surface of the silver film is a result of the gradient growth of silver crystals. The free energy of Ge atoms is reduced by their migration from boundaries of larger grains at the Ag/SiO 2 interface to boundaries of smaller grains near the Ag surface. Annealing at different temperatures and various durations allowed for a controlled distribution of crystal dimensions, thus influencing the segregation rate. Furthermore, using ellipsometric and optical transmission measurements we determined the time-dependent evolution of the film structure. If stored under ambient conditions for the first week after deposition, the changes in the transmission spectra are smaller than the measurement accuracy. Over the course of the following three weeks, the segregation-induced effects result in considerably modified transmission spectra. Two months after deposition, the slope of the silver layer density profile derived from the XRR spectra was found to be inverted due to the completed segregation process, and the optical transmission spectra increased uniformly due to the roughened surfaces, corrosion of silver and ongoing recrystallization. The Raman spectra of the Ge wetted Ag films were measured immediately after deposition and ten days later and demonstrated that the Ge atoms at the Ag grain boundaries form clusters of a few atoms where the Ge-Ge bonds are still present.

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).

Trends in gender segregation in the choice of science and engineering majors.

PubMed

Mann, Allison; Diprete, Thomas A

2013-11-01

Numerous theories have been put forward for the high and continuing levels of gender segregation in science, technology, engineering, and mathematics (STEM) fields, but research has not systematically examined the extent to which these theories for the gender gap are consistent with actual trends. Using both administrative data and four separate longitudinal studies sponsored by the U.S. Department of Education's National Center for Education Statistics (NCES), we evaluate several prominent explanations for the persisting gender gap in STEM fields related to mathematics performance and background and general life goals, and find that none of them are empirically satisfactory. Instead, we suggest that the structure of majors and their linkages to professional training and careers may combine with gender differences in educational goals to influence the persisting gender gap in STEM fields. An analysis of gendered career aspirations, course-taking patterns, and pathways to medical and law school supports this explanation. Copyright © 2013 Elsevier Inc. All rights reserved.

Surface Structure Formation in Direct Chill (DC) Casting of Al Alloys

NASA Astrophysics Data System (ADS)

Bayat, Nazlin; Carlberg, Torbjörn

2014-05-01

The aim of this study is to increase the understanding of the surface zone formation during direct chill (DC) casting of aluminum billets produced by the air slip technology. The depth of the shell zone, with compositions deviating from the bulk, is of large importance for the subsequent extrusion productivity and quality of final products. The surface microstructures of 6060 and 6005 aluminum alloys in three different surface appearances—defect free, wavy surface, and spot defects—were studied. The surface microstructures and outer appearance, segregation depth, and phase formation were investigated for the mentioned cases. The results were discussed and explained based on the exudation of liquid metal through the mushy zone and the fact that the exudated liquid is contained within a surface oxide skin. Outward solidification in the surface layer was quantitatively analyzed, and the oxide skin movements explained meniscus line formation. Phases forming at different positions in the segregation zone were analyzed and coupled to a cellular solidification in the exudated layer.

Blood Cell Interactions and Segregation in Flow

PubMed Central

Munn, Lance L.; Dupin, Michael M.

2009-01-01

For more than a century, pioneering researchers have been using novel experimental and computational approaches to probe the mysteries of blood flow. Thanks to their efforts, we know that blood cells generally prefer to migrate to the axis of flow, that red and white cells segregate in flow, and that cell deformability and their tendency to reversibly aggregate contribute to the non-Newtonian nature of this unique fluid. All of these properties have beneficial physiological consequences, allowing blood to perform a variety of critical functions. Our current understanding of these unusual flow properties of blood have been made possible by the ingenuity and diligence of a number of researchers, including Harry Goldsmith, who developed novel technologies to visualize and quantify the flow of blood at the level of individual cells. Here we summarize efforts in our lab to continue this tradition and to further our understanding of how blood cells interact with each other and with the blood vessel wall. PMID:18188702

Phase Behavior of a Single Structured Ionomer Chain in Solution

DOE PAGES

Aryal, Dipak; Etampawala, Thusitha; Perahia, Dvora; ...

2014-08-14

Structured polymers offer a means to tailor transport pathways within mechanically stable manifolds. Here we examine the building block of such a membrane, namely a single large pentablock co-polymer that consist of a center block of a randomly sulfonated polystyrene, designed for transport, tethered to poly-ethylene-r-propylene and end-capped by poly-t-butyl styrene, for mechanical stability,using molecular dynamics simulations. The polymer structure in a cyclohexane-heptane mixture, a technologically viable solvent, and in water, a poor solvent for all segments and a ubiquitous substance is extracted. In all solvents the pentablock collapsed into nearly spherical aggregates where the ionic block is segregated. Inmore » hydrophobic solvents, the ionic block resides in the center, surrounded by swollen intermix of flexible and end blocks. In water all blocks are collapsed with the sulfonated block residing on the surface. Our results demonstrate that solvents drive different local nano-segregation, providing a gateway to assemble membranes with controlled topology.« less

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.

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.

Detecting novel genetic mutations in Chinese Usher syndrome families using next-generation sequencing technology.

PubMed

Qu, Ling-Hui; Jin, Xin; Xu, Hai-Wei; Li, Shi-Ying; Yin, Zheng-Qin

2015-02-01

Usher syndrome (USH) is the most common cause of combined blindness and deafness inherited in an autosomal recessive mode. Molecular diagnosis is of great significance in revealing the molecular pathogenesis and aiding the clinical diagnosis of this disease. However, molecular diagnosis remains a challenge due to high phenotypic and genetic heterogeneity in USH. This study explored an approach for detecting disease-causing genetic mutations in candidate genes in five index cases from unrelated USH families based on targeted next-generation sequencing (NGS) technology. Through systematic data analysis using an established bioinformatics pipeline and segregation analysis, 10 pathogenic mutations in the USH disease genes were identified in the five USH families. Six of these mutations were novel: c.4398G > A and EX38-49del in MYO7A, c.988_989delAT in USH1C, c.15104_15105delCA and c.6875_6876insG in USH2A. All novel variations segregated with the disease phenotypes in their respective families and were absent from ethnically matched control individuals. This study expanded the mutation spectrum of USH and revealed the genotype-phenotype relationships of the novel USH mutations in Chinese patients. Moreover, this study proved that targeted NGS is an accurate and effective method for detecting genetic mutations related to USH. The identification of pathogenic mutations is of great significance for elucidating the underlying pathophysiology of USH.

Effects of Resource Allocation on Student Academic Achievement and Self-Perceptions of Success in an Urban Setting

ERIC Educational Resources Information Center

Harris, Kimberly

2014-01-01

Civil Rights legislation, now 50 years old, "de facto" segregation based on socioeconomic factors, such as poverty and ethnicity in urban areas translates into the surrounding schools, with a legacy of limited funding, reduced services, and teachers with limited training to successfully engage students in high poverty areas. This study…

Fostering Sex Fairness in Vocational Education: Strategies for Administrators. Information Series No. 147.

ERIC Educational Resources Information Center

Steiger, JoAnn M.; Schlesinger, Sue H.

One of a series of sixteen knowledge transformation papers, this paper gives an overview of sex equity issues and suggests alternative strategies for administrators in vocational education to use in reducing sex segregation and fostering sex fairness. In the first section the nature of the problem is discussed; occupational sex stereotyping and…

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

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.

Population health in an era of rising income inequality: USA, 1980-2015.

PubMed

Bor, Jacob; Cohen, Gregory H; Galea, Sandro

2017-04-08

Income inequality in the USA has increased over the past four decades. Socioeconomic gaps in survival have also increased. Life expectancy has risen among middle-income and high-income Americans whereas it has stagnated among poor Americans and even declined in some demographic groups. Although the increase in income inequality since 1980 has been driven largely by soaring top incomes, the widening of survival inequalities has occurred lower in the distribution-ie, between the poor and upper-middle class. Growing survival gaps across income percentiles since 2001 reflect falling real incomes among poor Americans as well as an increasingly strong association between low income and poor health. Changes in individual risk factors such as smoking, obesity, and substance abuse play a part but do not fully explain the steeper gradient. Distal factors correlated with rising inequality including unequal access to technological innovations, increased geographical segregation by income, reduced economic mobility, mass incarceration, and increased exposure to the costs of medical care might have reduced access to salutary determinants of health among low-income Americans. Having missed out on decades of income growth and longevity gains, low-income Americans are increasingly left behind. Without interventions to decouple income and health, or to reduce inequalities in income, we might see the emergence of a 21st century health-poverty trap and the further widening and hardening of socioeconomic inequalities in health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Site-preference and valency for rare-earth sites in (R-Ce)(2)Fe14B magnets

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

Alam, A; Khan, M; McCallum, RW

2013-01-28

Rare-earth (R) permanent magnets of R2Fe14B have technological importance due to their high energy products, and they have two R-sites (Wyckoff 4f and 4g, with four-fold multiplicity) that affect chemistry and valence. Designing magnetic behavior and stability via alloying is technologically relevant to reduce critical (expensive) R-content while retaining key properties; cerium, an abundant (cheap) R-element, offers this potential. We calculate magnetic properties and Ce site preference in (R1-xCex)(2)Fe14B [R = La, Nd] using density functional theory (DFT) methods-including a DFT+U scheme to treat localized 4f-electrons. Fe moments compare well with neutron data-almost unaffected by Hubbard U, and weakly affectedmore » by spin-orbit coupling. In La2Fe14B, Ce alloys for 0 <= x <= 1 and prefers smaller R(4f) sites, as observed, a trend we find unaffected by valence. Whereas, in Nd2Fe14B, Ce is predicted to have limited alloying (x <= 0.3) with a preference for larger R(4g) sites, resulting in weak partial ordering and segregation. The Curie temperatures versus x for (Nd, Ce) were predicted for a typical sample processing and verified experimentally. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789527]« less

Split Cas9, Not Hairs - Advancing the Therapeutic Index of CRISPR Technology.

PubMed

Schmelas, Carolin; Grimm, Dirk

2018-01-05

The discovery that the bacterial CRISPR/Cas9 system can be translated into mammalian cells continues to have an unprecedented impact on the biomedical research community, as it largely facilitates efforts to experimentally interrogate or therapeutically modify the cellular genome. In particular, CRISPR promises the ability to correct disease-associated genetic defects, or to target and destroy invading foreign DNA, in a simple, efficient, and selective manner directly in affected human cells or tissues. Here, we highlight a set of exciting new strategies that aim at further increasing the therapeutic index of CRISPR technologies, by reducing the size of Cas9 expression cassettes and thus enhancing their compatibility with viral gene delivery vectors. Specifically, we discuss the concept of splitCas9 whereby the Cas9 holo-protein is segregated into two parts that are expressed individually and reunited in the cell by various means, including use of 1) the gRNA as a scaffold for Cas9 assembly; 2) the rapamycin-controlled FKBP/FRB system; 3) the light-regulated Magnet system; or 4) inteins. We describe how these avenues, despite pursuing the identical aim, differ in critical features comprising the extent of spatio-temporal control of CRISPR activity, and discuss additional improvements to their efficiency or specificity that should foster their clinical translation. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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. ...

Convection effects on radial segregation and crystal melt interface in vertical Bridgman growth

NASA Technical Reports Server (NTRS)

Tanveer, S.

1993-01-01

We analytically study the influence of convection caused by horizontal heat transfer through the sides of a vertical Bridgman apparatus. We consider the case when the heat transfer across the side walls is small so that the resulting interfacial deformation and fluid velocities are also small. This allows us to linearize the Navier-Stokes equations and express the interfacial conditions about a planar interface through a Taylor expansion. Using a no tangential stress conditions on the side walls, asymptotic expressions for both the interfacial slope, and radial segregation at the crystal-melt interface are obtained in closed form in the limit of large thermal Rayleigh number. It is suggested that these can be reduced by appropriately controlling a specific heat transfer property at the edge of the insulation zone in the solid side.

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)

Analysis of transgenic wheat (Triticum aestivum L.) harboring a maize (Zea mays L.) gene for plastid EF-Tu: segregation pattern, expression and effects of the transgene.

PubMed

Fu, Jianming; Ristic, Zoran

2010-06-01

We previously reported that transgenic wheat (Triticum aestivum L.) carrying a maize (Zea mays L.) gene (Zmeftu1) for chloroplast protein synthesis elongation factor, EF-Tu, displays reduced thermal aggregation of leaf proteins, reduced injury to photosynthetic membranes (thylakoids), and enhanced rate of CO(2) fixation following exposure to heat stress (18 h at 45 degrees C) [Fu et al. in Plant Mol Biol 68:277-288, 2008]. In the current study, we investigated the segregation pattern and expression of the transgene Zmeftu1 and determined the grain yield of transgenic plants after exposure to a brief heat stress (18 h at 45 degrees C). We also assessed thermal aggregation of soluble leaf proteins in transgenic plants, testing the hypothesis that increased levels of EF-Tu will lead to a non-specific protection of leaf proteins against thermal aggregation. The transgenic wheat displayed a single-gene pattern of segregation of Zmeftu1. Zmeftu1 was expressed, and the transgenic plants synthesized and accumulated three anti-EF-Tu cross-reacting polypeptides of similar molecular mass but different pI, suggesting the possibility of posttranslational modification of this protein. The transgenic plants also showed better grain yield after exposure to heat stress compared with their non-transgenic counterparts. Soluble leaf proteins of various molecular masses displayed lower thermal aggregation in transgenic than in non-transgenic wheat. The results suggest that overexpression of chloroplast EF-Tu can be beneficial to wheat tolerance to heat stress. Moreover, the results also support the hypothesis that EF-Tu contributes to heat tolerance by acting as a molecular chaperone and protecting heat-labile proteins from thermal aggregation in a non-specific manner.

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.

An Overview of Natural Gas Conversion Technologies for Co-Production of Hydrogen and Value-Added Solid Carbon Products

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

Dagle, Robert A.; Dagle, Vanessa; Bearden, Mark D.

This report was prepared in response to the U.S. Department of Energy Fuel Cell Technologies Office Congressional Appropriation language to support research on carbon-free production of hydrogen using new chemical processes that utilize natural gas to produce solid carbon and hydrogen. The U.S. produces 9-10 million tons of hydrogen annually with more than 95% of the hydrogen produced by steam-methane reforming (SMR) of natural gas. SMR is attractive because of its high hydrogen yield; but it also converts the carbon to carbon dioxide. Non-oxidative thermal decomposition of methane to carbon and hydrogen is an alternative to SMR and produces COmore » 2-free hydrogen. The produced carbon can be sold as a co-product, thus providing economic credit that reduces the delivered net cost of hydrogen. The combination of producing hydrogen with potentially valuable carbon byproducts has market value in that this allows greater flexibility to match the market prices of hydrogen and carbon. That is, the higher value product can subsidize the other in pricing decisions. In this report we highlight the relevant technologies reported in the literature—primarily thermochemical and plasma conversion processes—and recent research progress and commercial activities. Longstanding technical challenges include the high energetic requirements (e.g., high temperatures and/or electricity requirements) necessary for methane activation and, for some catalytic processes, the separation of solid carbon product from the spent catalyst. We assess current and new carbon product markets that could be served given technological advances, and we discuss technical barriers and potential areas of research to address these needs. We provide preliminary economic analysis for these processes and compare to other emerging (e.g., electrolysis) and conventional (e.g., SMR) processes for hydrogen production. The overarching conclusion of this study is that the cost of hydrogen can be potentially reduced to target levels of $2/kg with the co-production and sale of a sufficiently high-value carbon product. Technological advances are required to understand the reaction conditions and design reactor systems that can achieve high yields of the select carbon products and segregate or separate the high-value carbon products, and optimize the production process for both hydrogen and carbon.« less

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.

Fully Disposable Manufacturing Concepts for Clinical and Commercial Manufacturing and Ballroom Concepts.

PubMed

Boedeker, Berthold; Goldstein, Adam; Mahajan, Ekta

2017-11-04

The availability and use of pre-sterilized disposables has greatly changed the methods used in biopharmaceuticals development and production, particularly from mammalian cell culture. Nowadays, almost all process steps from cell expansion, fermentation, cell removal, and purification to formulation and storage of drug substances can be carried out in disposables, although there are still limitations with single-use technologies, particularly in the areas of pretesting and quality control of disposables, bag and connections standardization and qualification, extractables and leachables (E/L) validation, and dependency on individual vendors. The current status of single-use technologies is summarized for all process unit operations using a standard mAb process as an example. In addition, current pros and cons of using disposables are addressed in a comparative way, including quality control and E/L validation.The continuing progress in developing single-use technologies has an important impact on manufacturing facilities, resulting in much faster, less expensive and simpler plant design, start-up, and operation, because cell culture process steps are no longer performed in hard-piped unit operations. This leads to simpler operations in a lab-like environment. Overall it enriches the current landscape of available facilities from standard hard-piped to hard-piped/disposables hybrid to completely single-use-based production plants using the current segregation and containment concept. At the top, disposables in combination with completely and functionally closed systems facilitate a new, revolutionary design of ballroom facilities without or with much less segregation, which enables us to perform good manufacturing practice manufacturing of different products simultaneously in unclassified but controlled areas.Finally, single-use processing in lab-like shell facilities is a big enabler of transferring and establishing production in emergent countries, and this is described in more detail in 7. Graphical Abstract.

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.

Effect of P impurity on mechanical properties of NiAl Σ5 grain boundary: From perspectives of stress and energy

NASA Astrophysics Data System (ADS)

Hu, Xue-Lan; Zhao, Ruo-Xi; Deng, Jiang-Ge; Hu, Yan-Min; Song, Qing-Gong

2018-03-01

In this paper, we employ the first-principle total energy method to investigate the effect of P impurity on mechanical properties of NiAl grain boundary (GB). According to “energy”, the segregation of P atom in NiAlΣ5 GB reduces the cleavage energy and embrittlement potential, demonstrating that P impurity embrittles NiAlΣ5 GB. The first-principle computational tensile test is conducted to determine the theoretical tensile strength of NiAlΣ5 GB. It is demonstrated that the maximum ideal tensile strength of NiAlΣ5 GB with P atom segregation is 144.5 GPa, which is lower than that of the pure NiAlΣ5 GB (164.7 GPa). It is indicated that the segregation of P weakens the theoretical strength of NiAlΣ5 GB. The analysis of atomic configuration shows that the GB fracture is caused by the interfacial bond breaking. Moreover, P is identified to weaken the interactions between Al–Al bonds and enhance Ni–Ni bonds. Project supported by the National Natural Science Foundation of China (Grant Nos. 11404396 and 51201181) and the Subject Construction Fund of Civil Aviation University of China (Grant No. 000032041102).

Altered segregation between task-positive and task-negative regions in mild traumatic brain injury.

PubMed

Sours, Chandler; Kinnison, Joshua; Padmala, Srikanth; Gullapalli, Rao P; Pessoa, Luiz

2018-06-01

Changes in large-scale brain networks that accompany mild traumatic brain injury (mTBI) were investigated using functional magnetic resonance imaging (fMRI) during the N-back working memory task at two cognitive loads (1-back and 2-back). Thirty mTBI patients were examined during the chronic stage of injury and compared to 28 control participants. Demographics and behavioral performance were matched across groups. Due to the diffuse nature of injury, we hypothesized that there would be an imbalance in the communication between task-positive and Default Mode Network (DMN) regions in the context of effortful task execution. Specifically, a graph-theoretic measure of modularity was used to quantify the extent to which groups of brain regions tended to segregate into task-positive and DMN sub-networks. Relative to controls, mTBI patients showed reduced segregation between the DMN and task-positive networks, but increased functional connectivity within the DMN regions during the more cognitively demanding 2-back task. Together, our findings reveal that patients exhibit alterations in the communication between and within neural networks during a cognitively demanding task. These findings reveal altered processes that persist through the chronic stage of injury, highlighting the need for longitudinal research to map the neural recovery of mTBI patients.

Three-dimensional phase segregation of micro-porous layers for fuel cells by nano-scale X-ray computed tomography

NASA Astrophysics Data System (ADS)

Andisheh-Tadbir, Mehdi; Orfino, Francesco P.; Kjeang, Erik

2016-04-01

Modern hydrogen powered polymer electrolyte fuel cells (PEFCs) utilize a micro-porous layer (MPL) consisting of carbon nanoparticles and polytetrafluoroethylene (PTFE) to enhance the transport phenomena and performance while reducing cost. However, the underlying mechanisms are not yet completely understood due to a lack of information about the detailed MPL structure and properties. In the present work, the 3D phase segregated nanostructure of an MPL is revealed for the first time through the development of a customized, non-destructive procedure for monochromatic nano-scale X-ray computed tomography visualization. Utilizing this technique, it is discovered that PTFE is situated in conglomerated regions distributed randomly within connected domains of carbon particles; hence, it is concluded that PTFE acts as a binder for the carbon particles and provides structural support for the MPL. Exposed PTFE surfaces are also observed that will aid the desired hydrophobicity of the material. Additionally, the present approach uniquely enables phase segregated calculation of effective transport properties, as reported herein, which is particularly important for accurate estimation of electrical and thermal conductivity. Overall, the new imaging technique and associated findings may contribute to further performance improvements and cost reduction in support of fuel cell commercialization for clean energy applications.

Conditional mutation of Smc5 in mouse embryonic stem cells perturbs condensin localization and mitotic progression.

PubMed

Pryzhkova, Marina V; Jordan, Philip W

2016-04-15

Correct duplication of stem cell genetic material and its appropriate segregation into daughter cells are requisites for tissue, organ and organism homeostasis. Disruption of stem cell genomic integrity can lead to developmental abnormalities and cancer. Roles of the Smc5/6 structural maintenance of chromosomes complex in pluripotent stem cell genome maintenance have not been investigated, despite its important roles in DNA synthesis, DNA repair and chromosome segregation as evaluated in other model systems. Using mouse embryonic stem cells (mESCs) with a conditional knockout allele of Smc5, we showed that Smc5 protein depletion resulted in destabilization of the Smc5/6 complex, accumulation of cells in G2 phase of the cell cycle and apoptosis. Detailed assessment of mitotic mESCs revealed abnormal condensin distribution and perturbed chromosome segregation, accompanied by irregular spindle morphology, lagging chromosomes and DNA bridges. Mutation of Smc5 resulted in retention of Aurora B kinase and enrichment of condensin on chromosome arms. Furthermore, we observed reduced levels of Polo-like kinase 1 at kinetochores during mitosis. Our study reveals crucial requirements of the Smc5/6 complex during cell cycle progression and for stem cell genome maintenance. © 2016. Published by The Company of Biologists Ltd.

Computational Fluid Dynamics Modeling of Macrosegregation and Shrinkage in Large-Diameter Steel Roll Castings

NASA Astrophysics Data System (ADS)

Nastac, Laurentiu

2011-12-01

Minimizing macrosegregation and shrinkage in large cast steel mill rolls challenges the limits of commercial foundry technology. Processing improvements have been achieved by balancing the total heat input of casting with the rate of heat extraction from the surface of the roll in the mold. A submerged entry nozzle (SEN) technique that injects a dilute alloy addition through a nozzle into the partially solidified net-shaped roll ingot can mitigate both centerline segregation and midradius channel segregate conditions. The objective of this study is to optimize the melt chemistry, solidification, and SEN conditions to minimize centerline and midradius segregation, and then to improve the quality of the transition region between the outer shell and the diluted interior region. To accomplish this objective, a multiphase, multicomponent computational fluid dynamics (CFD) code was developed for studying the macrosegregation and shrinkage under various casting conditions for a 65-ton, 1.6-m-diameter steel roll. The developed CFD framework consists of solving for the volume fraction of phases (air and steel mixture), temperature, flow, and solute balance in multicomponent alloy systems. Thermal boundary conditions were determined by measuring the temperature in the mold at several radial depths and height locations. The thermophysical properties including viscosity of steel alloy used in the simulations are functions of temperature. The steel mixture in the species-transfer model consists of the following elements: Fe, Mn, Si, S, P, C, Cr, Mo, and V. Density and liquidus temperature of the steel mixture are locally affected by the segregation of these elements. The model predictions were validated against macrosegregation measured from pieces cut from the 65-ton roll. The effect of key processing parameters such as melt composition and superheat of both the shell and the dilute interior alloy are addressed. The influence of mold type and thickness on macrosegregation and shrinkage also are discussed.

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.

Genetic screening for PRA-associated mutations in multiple dog breeds shows that PRA is heterogeneous within and between breeds.

PubMed

Downs, Louise M; Hitti, Rebekkah; Pregnolato, Silvia; Mellersh, Cathryn S

2014-03-01

To assess the extent of progressive retinal atrophy (PRA) genetic heterogeneity within and between domestic dog breeds. DNA from 231 dogs with PRA, representing 36 breeds, was screened for 17 mutations previously associated with PRA in at least one breed of dog. Screening methods included amplified fragment size discrimination using gel electrophoresis or detection of fluorescence, (TaqMan(®) ; Life Technologies, Carlsbad, CA, USA) allelic discrimination, and Sanger sequencing. Of the 231 dogs screened, 129 were homozygous for a PRA-associated mutation, 29 dogs were carriers, and 73 were homozygous for the wild-type allele at all loci tested. In two of the 129 dogs, homozygous mutations were identified that had not previously been observed in the respective breeds: one Chinese Crested dog was homozygous for the RCD3-associated mutation usually found in the Cardigan Welsh Corgi, and one Standard Poodle was homozygous for the RCD4-associated mutation previously reported to segregate in Gordon and Irish Setters. In the majority of the breeds (15/21) in which a PRA-associated mutation is known to segregate, cases were identified that did not carry any of the known PRA-associated mutations. Progressive retinal atrophy in the dog displays significant genetic heterogeneity within as well as between breeds. There are also several instances where PRA-associated mutations segregate among breeds with no known close ancestry. © 2013 American College of Veterinary Ophthalmologists.

Achieving continuous manufacturing for final dosage formation: challenges and how to meet them. May 20-21, 2014 Continuous Manufacturing Symposium.

PubMed

Byrn, Stephen; Futran, Maricio; Thomas, Hayden; Jayjock, Eric; Maron, Nicola; Meyer, Robert F; Myerson, Allan S; Thien, Michael P; Trout, Bernhardt L

2015-03-01

We describe the key issues and possibilities for continuous final dosage formation, otherwise known as downstream processing or drug product manufacturing. A distinction is made between heterogeneous processing and homogeneous processing, the latter of which is expected to add more value to continuous manufacturing. We also give the key motivations for moving to continuous manufacturing, some of the exciting new technologies, and the barriers to implementation of continuous manufacturing. Continuous processing of heterogeneous blends is the natural first step in converting existing batch processes to continuous. In heterogeneous processing, there are discrete particles that can segregate, versus in homogeneous processing, components are blended and homogenized such that they do not segregate. Heterogeneous processing can incorporate technologies that are closer to existing technologies, where homogeneous processing necessitates the development and incorporation of new technologies. Homogeneous processing has the greatest potential for reaping the full rewards of continuous manufacturing, but it takes long-term vision and a more significant change in process development than heterogeneous processing. Heterogeneous processing has the detriment that, as the technologies are adopted rather than developed, there is a strong tendency to incorporate correction steps, what we call below "The Rube Goldberg Problem." Thus, although heterogeneous processing will likely play a major role in the near-term transformation of heterogeneous to continuous processing, it is expected that homogeneous processing is the next step that will follow. Specific action items for industry leaders are: Form precompetitive partnerships, including industry (pharmaceutical companies and equipment manufacturers), government, and universities. These precompetitive partnerships would develop case studies of continuous manufacturing and ideally perform joint-technology development, including development of small-scale equipment and processes. Develop ways to invest internally in continuous manufacturing. How best to do this will depend on the specifics of a given organization, in particular the current development projects. Upper managers will need to energize their process developers to incorporate continuous manufacturing in at least part of their processes to gain experience and demonstrate directly the benefits. Training of continuous manufacturing technologies, organizational approaches, and regulatory approaches is a key area that industrial leaders should pursue together. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Effects of rapid thermal annealing on crystallinity and Sn surface segregation of {{Ge}}_{1-{\\boldsymbol{x}}}{{Sn}}_{{\\boldsymbol{x}}} films on Si (100) and Si (111)

NASA Astrophysics Data System (ADS)

Miao, Yuan-Hao; Hu, Hui-Yong; Song, Jian-Jun; Xuan, Rong-Xi; Zhang, He-Ming

2017-12-01

Not Available Project supported by the National Natural Science Foundation of China (Grant Nos. 61474085 and 61704130), the Science Research Plan in Shaanxi Province, China (Grant No. 2016GY-085), the Opening Project of Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences (Grant No. 90109162905), and the Fundamental Research Funds for the Central Universities, China (Grant No. 61704130).

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.

Corrosion Protection by Calcite-Type Coatings

DTIC Science & Technology

1989-10-01

CORROSION PROTECTION BY CALCITE -TYPE COATINGS OCTOBER, 1989 Prepared by: OCEAN CITY RESEARCH CORPORATION Tennessee Avenue & Beach Thorofare Ocean...REPORT DATE OCT 1989 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Corrosion Protection by Calcite -Type Coatings 5a. CONTRACT... calcite -type coatings to segregated seawater ballast tanks. If perfected, a calcite coating approach could substantially reduce the cost of corrosion

International Policy and Roma Education in Europe: Essential Inputs or Centralized Distractions?

ERIC Educational Resources Information Center

Ram, Melanie H.

2015-01-01

This article examines the case of Roma inclusion in education as a study of the ways in which international policy can and cannot bring change at the local level. I first reflect on the numerous international organizations and initiatives to improve the educational outcomes of Roma, and to reduce segregation and other non-inclusionary practices.…

Single nucleotide polymorphism discovery in rainbow trout by deep sequencing of a reduced representation library.

PubMed

Sánchez, Cecilia Castaño; Smith, Timothy P L; Wiedmann, Ralph T; Vallejo, Roger L; Salem, Mohamed; Yao, Jianbo; Rexroad, Caird E

2009-11-25

To enhance capabilities for genomic analyses in rainbow trout, such as genomic selection, a large suite of polymorphic markers that are amenable to high-throughput genotyping protocols must be identified. Expressed Sequence Tags (ESTs) have been used for single nucleotide polymorphism (SNP) discovery in salmonids. In those strategies, the salmonid semi-tetraploid genomes often led to assemblies of paralogous sequences and therefore resulted in a high rate of false positive SNP identification. Sequencing genomic DNA using primers identified from ESTs proved to be an effective but time consuming methodology of SNP identification in rainbow trout, therefore not suitable for high throughput SNP discovery. In this study, we employed a high-throughput strategy that used pyrosequencing technology to generate data from a reduced representation library constructed with genomic DNA pooled from 96 unrelated rainbow trout that represent the National Center for Cool and Cold Water Aquaculture (NCCCWA) broodstock population. The reduced representation library consisted of 440 bp fragments resulting from complete digestion with the restriction enzyme HaeIII; sequencing produced 2,000,000 reads providing an average 6 fold coverage of the estimated 150,000 unique genomic restriction fragments (300,000 fragment ends). Three independent data analyses identified 22,022 to 47,128 putative SNPs on 13,140 to 24,627 independent contigs. A set of 384 putative SNPs, randomly selected from the sets produced by the three analyses were genotyped on individual fish to determine the validation rate of putative SNPs among analyses, distinguish apparent SNPs that actually represent paralogous loci in the tetraploid genome, examine Mendelian segregation, and place the validated SNPs on the rainbow trout linkage map. Approximately 48% (183) of the putative SNPs were validated; 167 markers were successfully incorporated into the rainbow trout linkage map. In addition, 2% of the sequences from the validated markers were associated with rainbow trout transcripts. The use of reduced representation libraries and pyrosequencing technology proved to be an effective strategy for the discovery of a high number of putative SNPs in rainbow trout; however, modifications to the technique to decrease the false discovery rate resulting from the evolutionary recent genome duplication would be desirable.

Notch3 is necessary for neuronal differentiation and maturation in the adult spinal cord

PubMed Central

Rusanescu, Gabriel; Mao, Jianren

2014-01-01

Notch receptors are key regulators of nervous system development and promoters of neural stem cells renewal and proliferation. Defects in the expression of Notch genes result in severe, often lethal developmental abnormalities. Notch3 is generally thought to have a similar proliferative, anti-differentiation and gliogenic role to Notch1. However, in some cases, Notch3 has an opposite, pro-differentiation effect. Here, we show that Notch3 segregates from Notch1 and is transiently expressed in adult rat and mouse spinal cord neuron precursors and immature neurons. This suggests that during the differentiation of adult neural progenitor cells, Notch signalling may follow a modified version of the classical lateral inhibition model, involving the segregation of individual Notch receptors. Notch3 knockout mice, otherwise neurologically normal, are characterized by a reduced number of mature inhibitory interneurons and an increased number of highly excitable immature neurons in spinal cord laminae I–II. As a result, these mice have permanently lower nociceptive thresholds, similar to chronic pain. These results suggest that defective neuronal differentiation, for example as a result of reduced Notch3 expression or activation, may underlie human cases of intractable chronic pain, such as fibromyalgia and neuropathic pain. PMID:25164209

Determination of gaseous fission product behavior near the cerium dioxide Σ 3 (111)/[11 bar0] tilt grain boundary via first-principles study

NASA Astrophysics Data System (ADS)

Xi, Jianqi; Liu, Bin; Xu, Haixuan; Zhang, Yanwen; Weber, William J.

2018-02-01

Grain boundaries (GBs) are the most abundant structural defects in nanostructured nuclear fuels and play an important role in determining fission product behavior, which further affects the performance of nuclear fuels. In this work, cerium dioxide (CeO2) is used as a surrogate material for mixed oxide fuels to understand gaseous fission product behavior, specifically Xe. First-principles calculations are employed to comprehensively study the behavior of Xe and trap sites for Xe near the Σ 3 (111)/[11 bar0] grain boundary in CeO2, which will provide guidance on overall trends for Xe stability and diffusion at grain boundaries vs in the bulk. Significant segregation behavior of trap sites, regardless of charge states, is observed near the GB. This is mainly ascribed to the local atomic structure near the GB, which results in weaker bond strength and more negative segregation energies. For Xe, however, the segregation profile near the GB is different. Our calculations show that, as the size of trap sites increases, the segregation propensity of Xe is reduced. In addition, under hyper-stoichiometric conditions, the solubility of Xe trapped at the GB is significantly higher than that in the bulk, suggesting higher Xe concentration than that in the bulk. The results of this work demonstrate that the diffusion mechanism of Xe in CeO2 is comparable to that in UO2. The diffusion activation energies of Xe atoms in the Σ 3 GB are lower than that in the bulk CeO2. These results suggest that the diffusivity of Xe atoms is higher along the GB than that in the bulk, which enhances the aggregation of Xe atoms near the GB.

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

VEP contrast sensitivity responses reveal reduced functional segregation of mid and high filters of visual channels in autism.

PubMed

Jemel, Boutheina; Mimeault, Daniel; Saint-Amour, Dave; Hosein, Anthony; Mottron, Laurent

2010-06-01

Despite the vast amount of behavioral data showing a pronounced tendency in individuals with autism spectrum disorder (ASD) to process fine visual details, much less is known about the neurophysiological characteristics of spatial vision in ASD. Here, we address this issue by assessing the contrast sensitivity response properties of the early visual-evoked potentials (VEPs) to sine-wave gratings of low, medium and high spatial frequencies in adults with ASD and in an age- and IQ-matched control group. Our results show that while VEP contrast responses to low and high spatial frequency gratings did not differ between ASD and controls, early VEPs to mid spatial frequency gratings exhibited similar response characteristics as those to high spatial frequency gratings in ASD. Our findings show evidence for an altered functional segregation of early visual channels, especially those responsible for processing mid- and high-frequency spatial scales.

Mutations in genes encoding condensin complex proteins cause microcephaly through decatenation failure at mitosis

PubMed Central

Martin, Carol-Anne; Murray, Jennie E.; Carroll, Paula; Leitch, Andrea; Mackenzie, Karen J.; Halachev, Mihail; Fetit, Ahmed E.; Keith, Charlotte; Bicknell, Louise S.; Fluteau, Adeline; Gautier, Philippe; Hall, Emma A.; Joss, Shelagh; Soares, Gabriela; Silva, João; Bober, Michael B.; Duker, Angela; Wise, Carol A.; Quigley, Alan J.; Phadke, Shubha R.; Wood, Andrew J.; Vagnarelli, Paola; Jackson, Andrew P.

2016-01-01

Compaction of chromosomes is essential for accurate segregation of the genome during mitosis. In vertebrates, two condensin complexes ensure timely chromosome condensation, sister chromatid disentanglement, and maintenance of mitotic chromosome structure. Here, we report that biallelic mutations in NCAPD2, NCAPH, or NCAPD3, encoding subunits of these complexes, cause microcephaly. In addition, hypomorphic Ncaph2 mice have significantly reduced brain size, with frequent anaphase chromatin bridge formation observed in apical neural progenitors during neurogenesis. Such DNA bridges also arise in condensin-deficient patient cells, where they are the consequence of failed sister chromatid disentanglement during chromosome compaction. This results in chromosome segregation errors, leading to micronucleus formation and increased aneuploidy in daughter cells. These findings establish “condensinopathies” as microcephalic disorders, with decatenation failure as an additional disease mechanism for microcephaly, implicating mitotic chromosome condensation as a key process ensuring mammalian cerebral cortex size. PMID:27737959

Consequences of Asexuality in Natural Populations: Insights from Stick Insects.

PubMed

Bast, Jens; Parker, Darren J; Dumas, Zoé; Jalvingh, Kirsten M; Tran Van, Patrick; Jaron, Kamil S; Figuet, Emeric; Brandt, Alexander; Galtier, Nicolas; Schwander, Tanja

2018-07-01

Recombination is a fundamental process with significant impacts on genome evolution. Predicted consequences of the loss of recombination include a reduced effectiveness of selection, changes in the amount of neutral polymorphisms segregating in populations, and an arrest of GC-biased gene conversion. Although these consequences are empirically well documented for nonrecombining genome portions, it remains largely unknown if they extend to the whole genome scale in asexual organisms. We identify the consequences of asexuality using de novo transcriptomes of five independently derived, obligately asexual lineages of stick insects, and their sexual sister-species. We find strong evidence for higher rates of deleterious mutation accumulation, lower levels of segregating polymorphisms and arrested GC-biased gene conversion in asexuals as compared with sexuals. Taken together, our study conclusively shows that predicted consequences of genome evolution under asexuality can indeed be found in natural populations.

Heterozygous SSBP1 start loss mutation co-segregates with hearing loss and the m.1555A>G mtDNA variant in a large multigenerational family.

PubMed

Kullar, Peter J; Gomez-Duran, Aurora; Gammage, Payam A; Garone, Caterina; Minczuk, Michal; Golder, Zoe; Wilson, Janet; Montoya, Julio; Häkli, Sanna; Kärppä, Mikko; Horvath, Rita; Majamaa, Kari; Chinnery, Patrick F

2018-01-01

The m.1555A>G mtDNA variant causes maternally inherited deafness, but the reasons for the highly variable clinical penetrance are not known. Exome sequencing identified a heterozygous start loss mutation in SSBP1, encoding the single stranded binding protein 1 (SSBP1), segregating with hearing loss in a multi-generational family transmitting m.1555A>G, associated with mtDNA depletion and multiple deletions in skeletal muscle. The SSBP1 mutation reduced steady state SSBP1 levels leading to a perturbation of mtDNA metabolism, likely compounding the intra-mitochondrial translation defect due to m.1555A>G in a tissue-specific manner. This family demonstrates the importance of rare trans-acting genetic nuclear modifiers in the clinical expression of mtDNA disease. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.

Communication: Influence of nanophase segregation on ion transport in room temperature ionic liquids

DOE PAGES

Griffin, Philip J.; Wang, Yangyang; Holt, Adam P.; ...

2016-04-21

In this paper, we report measurements of the ionic conductivity, shear viscosity, and structural dynamics in a homologous series of quaternary ammonium ionic liquids (ILs) and a prototypical imidazolium-based IL over a wide range of temperatures down to the glass transition. We find that the ionic conductivity of these materials generally decreases, while the shear viscosity correspondingly increases, with increasing volume fraction of aliphatic side groups. Upon crossing an aliphatic volume fraction of ~0.40, we observe a sharp, order-of-magnitude decrease in ionic conductivity and enhancement of viscosity, which coincides with the presence of long-lived, nanometer-sized alkyl aggregates. These strong changesmore » in dynamics are not mirrored in the ionicity of these ILs, which decreases nearly linearly with aliphatic volume fraction. Finally, our results demonstrate that nanophase segregation in neat ILs strongly reduces ionic conductivity primarily due to an aggregation-induced suppression of dynamics.« less

Effects of He implantation on radiation induced segregation in Cu-Au and Ni-Si alloys

NASA Astrophysics Data System (ADS)

Iwase, A.; Rehn, L. E.; Baldo, P. M.; Funk, L.

Effects of He implantation on radiation induced segregation (RIS) in Cu-Au and Ni-Si alloys were investigated using in situ Rutherford backscattering spectrometry during simultaneous irradiation with 1.5-MeV He and low-energy (100 or 400-keV) He ions at elevated temperatures. RIS during single He ion irradiation, and the effects of pre-implantation with low-energy He ions, were also studied. RIS near the specimen surface, which was pronounced during 1.5-MeV He single-ion irradiation, was strongly reduced under low-energy He single-ion irradiation, and during simultaneous irradiation with 1.5-MeV He and low-energy He ions. A similar RIS reduction was also observed in the specimens pre-implanted with low-energy He ions. The experimental results indicate that the accumulated He atoms cause the formation of small bubbles, which provide additional recombination sites for freely migrating defects.

Polymorphic mimicry, microhabitat use, and sex-specific behaviour.

PubMed

Joron, M

2005-05-01

In order to assess the adaptive importance of microhabitat segregation for the maintenance of mimetic diversity, I explore how flight height varies between the sympatric forms of the polymorphic butterfly Heliconius numata and their respective models in the genus Melinaea. There is no evidence for vertical stratification of mimicry rings in these tiger-patterned butterflies, but males of H. numata tend to fly significantly higher than females and the Melinaea models. This difference in microhabitat preference likely results from females searching for host plants whereas males are patrolling for mates. I then present an extension of Muller's mimicry model for the case of partial behavioural or spatial segregation of sexes. The analysis suggests that sex-specific behaviours can make mimicry more beneficial, simply by reducing the effective population size participating in mimicry. The interaction between mimicry and sex-specific behaviours may therefore facilitate the evolution of polymorphism via enhanced, fine-scale local adaptation.

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

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.

A high-density consensus map of barley linking DArT markers to SSR, RFLP and STS loci and agricultural traits

PubMed Central

Wenzl, Peter; Li, Haobing; Carling, Jason; Zhou, Meixue; Raman, Harsh; Paul, Edie; Hearnden, Phillippa; Maier, Christina; Xia, Ling; Caig, Vanessa; Ovesná, Jaroslava; Cakir, Mehmet; Poulsen, David; Wang, Junping; Raman, Rosy; Smith, Kevin P; Muehlbauer, Gary J; Chalmers, Ken J; Kleinhofs, Andris; Huttner, Eric; Kilian, Andrzej

2006-01-01

Background Molecular marker technologies are undergoing a transition from largely serial assays measuring DNA fragment sizes to hybridization-based technologies with high multiplexing levels. Diversity Arrays Technology (DArT) is a hybridization-based technology that is increasingly being adopted by barley researchers. There is a need to integrate the information generated by DArT with previous data produced with gel-based marker technologies. The goal of this study was to build a high-density consensus linkage map from the combined datasets of ten populations, most of which were simultaneously typed with DArT and Simple Sequence Repeat (SSR), Restriction Enzyme Fragment Polymorphism (RFLP) and/or Sequence Tagged Site (STS) markers. Results The consensus map, built using a combination of JoinMap 3.0 software and several purpose-built perl scripts, comprised 2,935 loci (2,085 DArT, 850 other loci) and spanned 1,161 cM. It contained a total of 1,629 'bins' (unique loci), with an average inter-bin distance of 0.7 ± 1.0 cM (median = 0.3 cM). More than 98% of the map could be covered with a single DArT assay. The arrangement of loci was very similar to, and almost as optimal as, the arrangement of loci in component maps built for individual populations. The locus order of a synthetic map derived from merging the component maps without considering the segregation data was only slightly inferior. The distribution of loci along chromosomes indicated centromeric suppression of recombination in all chromosomes except 5H. DArT markers appeared to have a moderate tendency toward hypomethylated, gene-rich regions in distal chromosome areas. On the average, 14 ± 9 DArT loci were identified within 5 cM on either side of SSR, RFLP or STS loci previously identified as linked to agricultural traits. Conclusion Our barley consensus map provides a framework for transferring genetic information between different marker systems and for deploying DArT markers in molecular breeding schemes. The study also highlights the need for improved software for building consensus maps from high-density segregation data of multiple populations. PMID:16904008

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.

[Microarray CGH: principle and use for constitutional disorders].

PubMed

Sanlaville, D; Lapierre, J M; Coquin, A; Turleau, C; Vermeesch, J; Colleaux, L; Borck, G; Vekemans, M; Aurias, A; Romana, S P

2005-10-01

Chips technology has allowed to miniaturize process making possible to realize in one step and using the same device a lot of chemical reactions. The application of this technology to molecular cytogenetics resulted in the development of comparative genomic hybridization (CGH) on microarrays technique. Using this technique it is possible to detect very small genetic imbalances anywhere in the genome. Its usefulness has been well documented in cancer and more recently in constitutional disorders. In particular it has been used to detect interstitial and subtelomeric submicroscopic imbalances, to characterize their size at the molecular level or to define the breakpoints of translocation. The challenge today is to transfer this technology in laboratory medicine. Nevertheless this technology remains expensive and the existence of numerous sequence polymorphisms makes its interpretation difficult. Finally its is unlikely that it will make karyotyping obsolete as it does not allow to detect balanced rearrangements which after meiotic segregation might result in genome imbalance in the progeny.

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

Development of mass production technology for block copolymer lithographic materials

NASA Astrophysics Data System (ADS)

Himi, Toshiyuki; Matsuki, Ryota; Kosaka, Terumasa; Ogaki, Ryosuke; Kawaguchi, Yukio; Shimizu, Tetsuo

2017-03-01

We have successfully synthesized various and over wide range molecular weight block copolymers (BCPs): these are polystyrene(PS)-polymethylmethacrylate(PMMA) as general components and poly(4-trimethylsilylstyrene)(PTMSS)- poly(4-hydroxystyrene)(PHS) system as very strong segregated components (high chi) and multiblock type of those copolymers which form the microphase-separated structure pattern using living anionic polymerizing method by which the size of polymer can be precisely controlled. In addition, we were able to observe alternating lamellar and cylinder structures which were formed by our various BCPs using small angle X-ray scattering (SAXS). Moreover, we have successfully developed new apparatus for high volume manufacturing including our original technologies such as purification of monomer, improvement of wetted surface, and mechanical technology for high vacuum. And we have successfully synthesized all the BCPs with narrow molecular weight distribution (PDI <1.1) with large-scale apparatus.

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.

Defining the Role of ATP Hydrolysis in Mitotic Segregation of Bacterial Plasmids

PubMed Central

Ah-Seng, Yoan; Rech, Jérôme; Lane, David; Bouet, Jean-Yves

2013-01-01

Hydrolysis of ATP by partition ATPases, although considered a key step in the segregation mechanism that assures stable inheritance of plasmids, is intrinsically very weak. The cognate centromere-binding protein (CBP), together with DNA, stimulates the ATPase to hydrolyse ATP and to undertake the relocation that incites plasmid movement, apparently confirming the need for hydrolysis in partition. However, ATP-binding alone changes ATPase conformation and properties, making it difficult to rigorously distinguish the substrate and cofactor roles of ATP in vivo. We had shown that mutation of arginines R36 and R42 in the F plasmid CBP, SopB, reduces stimulation of SopA-catalyzed ATP hydrolysis without changing SopA-SopB affinity, suggesting the role of hydrolysis could be analyzed using SopA with normal conformational responses to ATP. Here, we report that strongly reducing SopB-mediated stimulation of ATP hydrolysis results in only slight destabilization of mini-F, although the instability, as well as an increase in mini-F clustering, is proportional to the ATPase deficit. Unexpectedly, the reduced stimulation also increased the frequency of SopA relocation over the nucleoid. The increase was due to drastic shortening of the period spent by SopA at nucleoid ends; average speed of migration per se was unchanged. Reduced ATP hydrolysis was also associated with pronounced deviations in positioning of mini-F, though time-averaged positions changed only modestly. Thus, by specifically targeting SopB-stimulated ATP hydrolysis our study reveals that even at levels of ATPase which reduce the efficiency of splitting clusters and the constancy of plasmid positioning, SopB still activates SopA mobility and plasmid positioning, and sustains near wild type levels of plasmid stability. PMID:24367270

Diversity arrays technology (DArT) markers in apple for genetic linkage maps.

PubMed

Schouten, Henk J; van de Weg, W Eric; Carling, Jason; Khan, Sabaz Ali; McKay, Steven J; van Kaauwen, Martijn P W; Wittenberg, Alexander H J; Koehorst-van Putten, Herma J J; Noordijk, Yolanda; Gao, Zhongshan; Rees, D Jasper G; Van Dyk, Maria M; Jaccoud, Damian; Considine, Michael J; Kilian, Andrzej

2012-03-01

Diversity Arrays Technology (DArT) provides a high-throughput whole-genome genotyping platform for the detection and scoring of hundreds of polymorphic loci without any need for prior sequence information. The work presented here details the development and performance of a DArT genotyping array for apple. This is the first paper on DArT in horticultural trees. Genetic mapping of DArT markers in two mapping populations and their integration with other marker types showed that DArT is a powerful high-throughput method for obtaining accurate and reproducible marker data, despite the low cost per data point. This method appears to be suitable for aligning the genetic maps of different segregating populations. The standard complexity reduction method, based on the methylation-sensitive PstI restriction enzyme, resulted in a high frequency of markers, although there was 52-54% redundancy due to the repeated sampling of highly similar sequences. Sequencing of the marker clones showed that they are significantly enriched for low-copy, genic regions. The genome coverage using the standard method was 55-76%. For improved genome coverage, an alternative complexity reduction method was examined, which resulted in less redundancy and additional segregating markers. The DArT markers proved to be of high quality and were very suitable for genetic mapping at low cost for the apple, providing moderate genome coverage. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11032-011-9579-5) contains supplementary material, which is available to authorized users.

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.

Study of the Effect of Trace Mg Additions on Carbides in Die Steel H13

NASA Astrophysics Data System (ADS)

Li, Ji; Li, Jing; Wang, Liang-liang; Zhu, Qin-tian

2016-09-01

Carbides in annealed steel H13 without magnesium and with a micro-addition of magnesium (0.0010%) are studied. Trace amounts of magnesium strengthen carbide segregation and reduce their size. Carbides phases M7C3, M6 C, and M(C, N) are detected in steel H13, and this agrees with results of thermodynamic calculations.

Is There Something Rotten in the State of Denmark? The Paradoxical Policies of Inclusive Education--Lessons from Denmark

ERIC Educational Resources Information Center

Engsig, Thomas T.; Johnstone, Christopher J.

2015-01-01

By 2015, 96% of the entire student body in the Danish public school system must receive his or her education within the regular classrooms, and referrals to segregated special education must be reduced radically. This is the consequence of the so-called "Inclusion Law" passed in the Danish parliament in April 2012. The law contains a…

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.

Structure and properties of small molecule-polymer blend semiconductors for organic thin film transistors.

PubMed

Kang, Jihoon; Shin, Nayool; Jang, Do Young; Prabhu, Vivek M; Yoon, Do Y

2008-09-17

A comprehensive structural and electrical characterization of solution-processed blend films of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) semiconductor and poly(alpha-methylstyrene) (PalphaMS) insulator was performed to understand and optimize the blend semiconductor films, which are very attractive as the active layer in solution-processed organic thin-film transistors (OTFTs). Our study, based on careful measurements of specular neutron reflectivity and grazing-incidence X-ray diffraction, showed that the blends with a low molecular-mass PalphaMS exhibited a strong segregation of TIPS-pentacene only at the air interface, but surprisingly the blends with a high molecular-mass PalphaMS showed a strong segregation of TIPS-pentacene at both air and bottom substrate interfaces with high crystallinity and desired orientation. This finding led to the preparation of a TIPS-pentacene/PalphaMS blend active layer with superior performance characteristics (field-effect mobility, on/off ratio, and threshold voltage) over those of neat TIPS-pentacene, as well as the solution-processability of technologically attractive bottom-gate/bottom-contact OTFT devices.

3-D Ultrastructure of O. tauri: Electron Cryotomography of an Entire Eukaryotic Cell

PubMed Central

Henderson, Gregory P.; Gan, Lu; Jensen, Grant J.

2007-01-01

The hallmark of eukaryotic cells is their segregation of key biological functions into discrete, membrane-bound organelles. Creating accurate models of their ultrastructural complexity has been difficult in part because of the limited resolution of light microscopy and the artifact-prone nature of conventional electron microscopy. Here we explored the potential of the emerging technology electron cryotomography to produce three-dimensional images of an entire eukaryotic cell in a near-native state. Ostreococcus tauri was chosen as the specimen because as a unicellular picoplankton with just one copy of each organelle, it is the smallest known eukaryote and was therefore likely to yield the highest resolution images. Whole cells were imaged at various stages of the cell cycle, yielding 3-D reconstructions of complete chloroplasts, mitochondria, endoplasmic reticula, Golgi bodies, peroxisomes, microtubules, and putative ribosome distributions in-situ. Surprisingly, the nucleus was seen to open long before mitosis, and while one microtubule (or two in some predivisional cells) was consistently present, no mitotic spindle was ever observed, prompting speculation that a single microtubule might be sufficient to segregate multiple chromosomes. PMID:17710148

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.

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.

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

PubMed

Farley, R

1986-01-01

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

Life cycle costing of waste management systems: overview, calculation principles and case studies.

PubMed

Martinez-Sanchez, Veronica; Kromann, Mikkel A; Astrup, Thomas Fruergaard

2015-02-01

This paper provides a detailed and comprehensive cost model for the economic assessment of solid waste management systems. The model was based on the principles of Life Cycle Costing (LCC) and followed a bottom-up calculation approach providing detailed cost items for all key technologies within modern waste systems. All technologies were defined per tonne of waste input, and each cost item within a technology was characterised by both a technical and an economic parameter (for example amount and cost of fuel related to waste collection), to ensure transparency, applicability and reproducibility. Cost items were classified as: (1) budget costs, (2) transfers (for example taxes, subsidies and fees) and (3) externality costs (for example damage or abatement costs related to emissions and disamenities). Technology costs were obtained as the sum of all cost items (of the same type) within a specific technology, while scenario costs were the sum of all technologies involved in a scenario. The cost model allows for the completion of three types of LCC: a Conventional LCC, for the assessment of financial costs, an Environmental LCC, for the assessment of financial costs whose results are complemented by a Life Cycle Assessment (LCA) for the same system, and a Societal LCC, for socio-economic assessments. Conventional and Environmental LCCs includes budget costs and transfers, while Societal LCCs includes budget and externality costs. Critical aspects were found in the existing literature regarding the cost assessment of waste management, namely system boundary equivalency, accounting for temporally distributed emissions and impacts, inclusions of transfers, the internalisation of environmental impacts and the coverage of shadow prices, and there was also significant confusion regarding terminology. The presented cost model was implemented in two case study scenarios assessing the costs involved in the source segregation of organic waste from 100,000 Danish households and the subsequent co-digestion of organic waste with animal manure. Overall, source segregation resulted in higher financial costs than the alternative of incinerating the organic waste with the residual waste: 1.6 M€/year, of which 0.9 M€/year was costs for extra bins and bags used by the households, 1.0 M€/year for extra collections and -0.3 M€/year saved on incineration. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Long-term energy security in a national scale using LEAP. Application to de-carbonization scenarios in Andorra

NASA Astrophysics Data System (ADS)

Travesset-Baro, Oriol; Jover, Eric; Rosas-Casals, Marti

2016-04-01

This paper analyses the long-term energy security in a national scale using Long-range Energy Alternatives Planning System (LEAP) modelling tool. It builds the LEAP Andorra model, which forecasts energy demand and supply for the Principality of Andorra by 2050. It has a general bottom-up structure, where energy demand is driven by the technological composition of the sectors of the economy. The technological model is combined with a top-down econometric model to take into account macroeconomic trends. The model presented in this paper provides an initial estimate of energy demand in Andorra segregated into all sectors (residential, transport, secondary, tertiary and public administration) and charts a baseline scenario based on historical trends. Additional scenarios representing different policy strategies are built to explore the country's potential energy savings and the feasibility to achieve the Intended Nationally Determined Contribution (INDC) submitted in April 2015 to UN. In this climatic agreement Andorra intends to reduce net greenhouse gas emissions (GHG) by 37% as compared to a business-as-usual scenario by 2030. In addition, current and future energy security is analysed in this paper under baseline and de-carbonization scenarios. Energy security issues are assessed in LEAP with an integrated vision, going beyond the classic perspective of security of supply, and being closer to the sustainability's integrative vision. Results of scenarios show the benefits of climate policies in terms of national energy security and the difficulties for Andorra to achieving the de-carbonization target by 2030.

Site-preference and valency for rare-earth sites in (R-Ce)2Fe14B [R =La,Nd] magnets

NASA Astrophysics Data System (ADS)

Alam, Aftab; Khan, Mahmud; McCallum, R. W.; Johnson, D. D.

2013-03-01

Rare-earth (R) permanent magnets of R2Fe14B have technological importance due to their high energy products, and they have two symmetry distinct R-sites (Wyckoff 4f and 4g) that affect chemistry and valence. Designing magnetic behavior and stability via alloying is technologically relevant to reduce critical (expensive) R-content while retaining key properties; cerium, an abundant (cheap) R-element, offers this potential. We calculate magnetic properties and Ce site preference in (R1-xCex)Fe14B [R=La,Nd] using density functional theory (DFT) methods. The Fe moments compare well with neutron scattering data - remain weakly affected by Hubbard U, but improved with spin-orbit coupling. In (La,Ce)2Fe14B, Ce alloys for 0 < x < 1 with a preference for smaller R(4f) sites, as observed, a trend we find unaffected by valence. Whereas in (Nd,Ce)2Fe14B, Ce is predicted to have limited alloying (x < 0.3) with a preference for larger R(4g) sites, resulting in weak partial ordering and segregation. Curie temperatures versus x were predicted for a typical sample processing and verified experimentally. We shall also present some initial results on the critical mixed valency of Ce in related compounds. Work at Ames Laboratory was supported by the U.S. Department of Energy, ARPA-E under the REACT program (0472-1526)

Short-term prediction of threatening and violent behaviour in an Acute Psychiatric Intensive Care Unit based on patient and environment characteristics.

PubMed

Vaaler, Arne E; Iversen, Valentina C; Morken, Gunnar; Fløvig, John C; Palmstierna, Tom; Linaker, Olav M

2011-03-18

The aims of the present study were to investigate clinically relevant patient and environment-related predictive factors for threats and violent incidents the first three days in a PICU population based on evaluations done at admittance. In 2000 and 2001 all 118 consecutive patients were assessed at admittance to a Psychiatric Intensive Care Unit (PICU). Patient-related conditions as actuarial data from present admission, global clinical evaluations by physician at admittance and clinical nurses first day, a single rating with an observer rated scale scoring behaviours that predict short-term violence in psychiatric inpatients (The Brøset Violence Checklist (BVC)) at admittance, and environment-related conditions as use of segregation or not were related to the outcome measure Staff Observation Aggression Scale-Revised (SOAS-R). A multiple logistic regression analysis with SOAS-R as outcome variable was performed. The global clinical evaluations and the BVC were effective and more suitable than actuarial data in predicting short-term aggression. The use of segregation reduced the number of SOAS-R incidents. In a naturalistic group of patients in a PICU segregation of patients lowers the number of aggressive and threatening incidents. Prediction should be based on clinical global judgment, and instruments designed to predict short-term aggression in psychiatric inpatients. NCT00184119/NCT00184132.

Short-term prediction of threatening and violent behaviour in an Acute Psychiatric Intensive Care Unit based on patient and environment characteristics

PubMed Central

2011-01-01

Background The aims of the present study were to investigate clinically relevant patient and environment-related predictive factors for threats and violent incidents the first three days in a PICU population based on evaluations done at admittance. Methods In 2000 and 2001 all 118 consecutive patients were assessed at admittance to a Psychiatric Intensive Care Unit (PICU). Patient-related conditions as actuarial data from present admission, global clinical evaluations by physician at admittance and clinical nurses first day, a single rating with an observer rated scale scoring behaviours that predict short-term violence in psychiatric inpatients (The Brøset Violence Checklist (BVC)) at admittance, and environment-related conditions as use of segregation or not were related to the outcome measure Staff Observation Aggression Scale-Revised (SOAS-R). A multiple logistic regression analysis with SOAS-R as outcome variable was performed. Results The global clinical evaluations and the BVC were effective and more suitable than actuarial data in predicting short-term aggression. The use of segregation reduced the number of SOAS-R incidents. Conclusions In a naturalistic group of patients in a PICU segregation of patients lowers the number of aggressive and threatening incidents. Prediction should be based on clinical global judgment, and instruments designed to predict short-term aggression in psychiatric inpatients. Trial registrations NCT00184119/NCT00184132 PMID:21418581

Aneuploidy in spermatids of Robertsonian (Rb) chromosome heterozygous mice.

PubMed

Manieu, Catalina; González, Marisel; López-Fenner, Julio; Page, Jesús; Ayarza, Eliana; Fernández-Donoso, Raúl; Berríos, Soledad

2014-12-01

Rb translocations are chromosomal rearrangements frequently found in natural populations of the house mouse Mus musculus domesticus. The standard diploid karyotype of the house mouse consisting of 40 telocentric chromosomes may be reduced by the emergence of metacentric Rb chromosomes. Multiple simple Rb heterozygotes form trivalents exhibiting higher anaphase nondisjunction frequency and consequently higher number of unbalanced gametes than in normal males. This work will attempt to establish whether frequencies of aneuploidy observed in heterozygote spermatids of the house mouse M. musculus domesticus show differences in chromosomes derived from different trivalents. Towards this goal, the number and distribution frequency of aneuploidy was assessed via FISH staining of specific chromosomes of spermatids derived from 2n = 32 individuals. Our results showed that for a given set of target chromosomes, 90% of the gametes were balanced, resulting from alternate segregation, and that there were no differences (approx. 10%) in aneuploidy frequencies in chromosomes derived from different trivalents. These observations suggest that segregation effectiveness does not depend on the type of chromosomes involved in trivalents. As a consequence of the trivalent's configuration, joint segregation of the telocentric chromosomes occurs thus favoring their appearance together in early spermatids. Our data suggest that Rb chromosomes and their telocentric homologs are subject to architectural constraints placing them close to each other. This proximity may ultimately facilitate fusion between them, hence contributing to a prevalence of Rb metacentric chromosomes.

The role of meiotic cohesin REC8 in chromosome segregation in gamma irradiation-induced endopolyploid tumour cells.

PubMed

Erenpreisa, Jekaterina; Cragg, Mark S; Salmina, Kristine; Hausmann, Michael; Scherthan, Harry

2009-09-10

Escape from mitotic catastrophe and generation of endopolyploid tumour cells (ETCs) represents a potential survival strategy of tumour cells in response to genotoxic treatments. ETCs that resume the mitotic cell cycle have reduced ploidy and are often resistant to these treatments. In search for a mechanism for genome reduction, we previously observed that ETCs express meiotic proteins among which REC8 (a meiotic cohesin component) is of particular interest, since it favours reductional cell division in meiosis. In the present investigation, we induced endopolyploidy in p53-dysfunctional human tumour cell lines (Namalwa, WI-L2-NS, HeLa) by gamma irradiation, and analysed the sub-cellular localisation of REC8 in the resulting ETCs. We observed by RT-PCR and Western blot that REC8 is constitutively expressed in these tumour cells, along with SGOL1 and SGOL2, and that REC8 becomes modified after irradiation. REC8 localised to paired sister centromeres in ETCs, the former co-segregating to opposite poles. Furthermore, REC8 localised to the centrosome of interphase ETCs and to the astral poles in anaphase cells where it colocalised with the microtubule-associated protein NuMA. Altogether, our observations indicate that radiation-induced ETCs express features of meiotic cell divisions and that these may facilitate chromosome segregation and genome reduction.

Models of Mass Transport During Microgravity Crystal Growth of Alloyed Semiconductors in a Magnetic Field

NASA Technical Reports Server (NTRS)

Ma, Nancy

2003-01-01

Alloyed semiconductor crystals, such as germanium-silicon (GeSi) and various II-VI alloyed crystals, are extremely important for optoelectronic devices. Currently, high-quality crystals of GeSi and of II-VI alloys can be grown by epitaxial processes, but the time required to grow a certain amount of single crystal is roughly 1,000 times longer than the time required for Bridgman growth from a melt. Recent rapid advances in optoelectronics have led to a great demand for more and larger crystals with fewer dislocations and other microdefects and with more uniform and controllable compositions. Currently, alloyed crystals grown by bulk methods have unacceptable levels of segregation in the composition of the crystal. Alloyed crystals are being grown by the Bridgman process in space in order to develop successful bulk-growth methods, with the hope that the technology will be equally successful on earth. Unfortunately some crystals grown in space still have unacceptable segregation, for example, due to residual accelerations. The application of a weak magnetic field during crystal growth in space may eliminate the undesirable segregation. Understanding and improving the bulk growth of alloyed semiconductors in microgravity is critically important. The purpose of this grant to to develop models of the unsteady species transport during the bulk growth of alloyed semiconductor crystals in the presence of a magnetic field in microgravity. The research supports experiments being conducted in the High Magnetic Field Solidification Facility at Marshall Space Flight Center (MSFC) and future experiments on the International Space Station.

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.