Different Faces in Our Classrooms: Teachers' Cultural Perspectives of Heterogeneous School Environments

ERIC Educational Resources Information Center

Hendricks, Paige

2016-01-01

The foundation of the United States' educational system is that all students will be educated equally by offering access to knowledge, opportunities, and services resulting in the creation of positive societal contributors. However, this task is complex and challenging. Heterogeneous student populations due to increased culturally diversity, do…

Properties of hypothesis testing techniques and (Bayesian) model selection for exploration-based and theory-based (order-restricted) hypotheses.

PubMed

Kuiper, Rebecca M; Nederhoff, Tim; Klugkist, Irene

2015-05-01

In this paper, the performance of six types of techniques for comparisons of means is examined. These six emerge from the distinction between the method employed (hypothesis testing, model selection using information criteria, or Bayesian model selection) and the set of hypotheses that is investigated (a classical, exploration-based set of hypotheses containing equality constraints on the means, or a theory-based limited set of hypotheses with equality and/or order restrictions). A simulation study is conducted to examine the performance of these techniques. We demonstrate that, if one has specific, a priori specified hypotheses, confirmation (i.e., investigating theory-based hypotheses) has advantages over exploration (i.e., examining all possible equality-constrained hypotheses). Furthermore, examining reasonable order-restricted hypotheses has more power to detect the true effect/non-null hypothesis than evaluating only equality restrictions. Additionally, when investigating more than one theory-based hypothesis, model selection is preferred over hypothesis testing. Because of the first two results, we further examine the techniques that are able to evaluate order restrictions in a confirmatory fashion by examining their performance when the homogeneity of variance assumption is violated. Results show that the techniques are robust to heterogeneity when the sample sizes are equal. When the sample sizes are unequal, the performance is affected by heterogeneity. The size and direction of the deviations from the baseline, where there is no heterogeneity, depend on the effect size (of the means) and on the trend in the group variances with respect to the ordering of the group sizes. Importantly, the deviations are less pronounced when the group variances and sizes exhibit the same trend (e.g., are both increasing with group number). © 2014 The British Psychological Society.

Modeling postshock evolution of large electropores

NASA Astrophysics Data System (ADS)

Neu, John C.; Krassowska, Wanda

2003-02-01

The Smoluchowski equation (SE), which describes the evolution of pores created by electric shocks, cannot be applied to modeling large and long-lived pores for two reasons: (1) it does not predict pores of radius above 20 nm without also predicting membrane rupture; (2) it does not predict postshock growth of pores. This study proposes a model in which pores are coupled by membrane tension, resulting in a nonlinear generalization of SE. The predictions of the model are explored using examples of homogeneous (all pore radii r are equal) and heterogeneous (0⩽r⩽rmax) distributions of pores. Pores in a homogeneous population either shrink to zero or assume a stable radius corresponding to the minimum of the bilayer energy. For a heterogeneous population, such a stable radius does not exist. All pores, except rmax, shrink to zero and rmax grows to infinity. However, the unbounded growth of rmax is not physical because the number of pores per cell decreases in time and the continuum model loses validity. When the continuum formulation is replaced by the discrete one, the model predicts the coarsening process: all pores, except rmax, shrink to zero and rmax assumes a stable radius. Thus, the model with tension-coupled pores does not predict membrane rupture and the predicted postshock growth of pores is consistent with experimental evidence.

Daring to Marry: Marriage Equality Activism After Proposition 8 as Challenge to the Assimilationist/Radical Binary in Queer Studies.

PubMed

Weber, Shannon

2015-01-01

I analyze three case studies of marriage equality activism and marriage equality-based groups after the passage of Proposition 8 in California. Evaluating the JoinTheImpact protests of 2008, the LGBTQ rights group GetEQUAL, and the group One Struggle One Fight, I argue that these groups revise queer theoretical arguments about marriage equality activism as by definition assimilationist, homonormative, and single-issue. In contrast to such claims, the cases studied here provide a snapshot of heterogeneous, intersectional, and coalition-based social justice work in which creative methods of protest, including direct action and flash mobs, are deployed in militant ways for marriage rights and beyond.

Role of deformation temperature on the evolution and heterogeneity of texture during equal channel angular pressing of magnesium

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

Biswas, Somjeet, E-mail: somjeetbiswas@gmail.com; Department of Materials Engineering, Indian Institute of Science, Bangalore 560012; Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures

Investigations on texture evolution and through-thickness texture heterogeneity during equal channel angular pressing (ECAP) of pure magnesium at 200 °C, 150 °C and room temperature (RT) was carried out by neutron, high energy synchrotron X-ray and electron back-scatter diffraction. Irrespective of the ECAP temperature, a distinctive basal (B) and pyramidal (C{sub 2}) II type of fibers forms. The texture differs in the bottom 1 mm portion, where the B-fiber is shifted ~ 55° due to negative shear attributed to friction. - Highlights: • ECAP of magnesium was carried out at 200 °C, 150 °C and room temperature. • Microstructure andmore » micro-texture evolution was examined using EBSD in FEG–SEM. • Bulk-texture was studied using neutron diffraction and compared with micro-texture. • Through thickness texture heterogeneity was observed by synchrotron radiation. • Changes in these parameters with respect to deformation temperature are discussed.« less

Small-scale heterogeneity spectra in the Earth mantle resolved by PKP-ab,-bc and -df waves

NASA Astrophysics Data System (ADS)

Zheng, Y.

2016-12-01

Plate tectonics creates heterogeneities at mid ocean ridges and subducts the heterogeneities back to the mantle at subduction zones. Heterogeneities manifest themselves by different densities and seismic wave speeds. The length scales and spatial distribution of the heterogeneities measure the mixing mechanism of the plate tectonics. This information can be mathematically captured as the heterogeneity spatial Fourier spectrum. Since most heterogeneities created are on the order of 10s of km, global seismic tomography is not able to resolve them directly. Here, we use seismic P-waves that transmit through the outer core (phases: PKP-ab and PKP-bc) and through the inner core (PKP-df) to probe the lower-mantle heterogeneities. The differential traveltimes (PKP-ab versus PKP-df; PKP-bc versus PKP-df) are sensitive to lower mantle structures. We have collected more than 10,000 PKP phases recorded by Japan Hi-Net short-period seismic network. We found that the lower mantle was filled with seismic heterogeneities from scale 20km to 200km. The heterogeneity spectrum is similar to an exponential distribution but is more enriched in small-scale heterogeneities at the high-wavenumber end. The spectrum is "red" meaning large scales have more power and heterogeneities show a multiscale nature: small-scale heterogeneities are embedded in large-scale heterogeneities. These small-scale heterogeneities cannot be due to thermal origin and they must be compositional. If all these heterogeneities were located in the D" layer, statistically, it would have a root-mean-square P-wave velocity fluctuation of 1% (i.e., -3% to 3%).

Impact of an equality constraint on the class-specific residual variances in regression mixtures: A Monte Carlo simulation study

PubMed Central

Kim, Minjung; Lamont, Andrea E.; Jaki, Thomas; Feaster, Daniel; Howe, George; Van Horn, M. Lee

2015-01-01

Regression mixture models are a novel approach for modeling heterogeneous effects of predictors on an outcome. In the model building process residual variances are often disregarded and simplifying assumptions made without thorough examination of the consequences. This simulation study investigated the impact of an equality constraint on the residual variances across latent classes. We examine the consequence of constraining the residual variances on class enumeration (finding the true number of latent classes) and parameter estimates under a number of different simulation conditions meant to reflect the type of heterogeneity likely to exist in applied analyses. Results showed that bias in class enumeration increased as the difference in residual variances between the classes increased. Also, an inappropriate equality constraint on the residual variances greatly impacted estimated class sizes and showed the potential to greatly impact parameter estimates in each class. Results suggest that it is important to make assumptions about residual variances with care and to carefully report what assumptions were made. PMID:26139512

Fair Shares, Matey, or Walk the Plank

ERIC Educational Resources Information Center

Wilson, P. Holt; Myers, Marrielle; Edgington, Cyndi; Confrey, Jere

2012-01-01

Whether sharing a collection of toys among friends or a pie for dessert, children as young as kindergarten age are keen on making sure that everyone gets their "fair share." In the classroom, fair-sharing activities call for creating equal-size groups from a collection of objects or creating equal-size parts of a whole and are generally used by…

Evidence for self-organization in determining spatial patterns of stream nutrients, despite primacy of the geomorphic template

PubMed Central

Dong, Xiaoli; Grimm, Nancy B.

2017-01-01

Nutrients in freshwater ecosystems are highly variable in space and time. Nevertheless, the variety of processes contributing to nutrient patchiness, and the wide range of spatial and temporal scales at which these processes operate, obfuscate how this spatial heterogeneity is generated. Here, we describe the spatial structure of stream nutrient concentration, quantify the relative importance of the physical template and biological processes, and detect and evaluate the role of self-organization in driving such patterns. We examined nutrient spatial patterns in Sycamore Creek, an intermittent desert stream in Arizona that experienced an ecosystem regime shift [from a gravel/algae-dominated to a vascular plant-dominated (hereafter, “wetland”) system] in 2000 when cattle grazing ceased. We conducted high-resolution nutrient surveys in surface water along a 10-km stream reach over four visits spanning 18 y (1995–2013) that represent different successional stages and prewetland stage vs. postwetland state. As expected, groundwater upwelling had a major influence on nutrient spatial patterns. However, self-organization realized by the mechanism of spatial feedbacks also was significant and intensified over ecosystem succession, as a resource (nitrogen) became increasingly limiting. By late succession, the effects of internal spatial feedbacks and groundwater upwelling were approximately equal in magnitude. Wetland establishment influenced nutrient spatial patterns only indirectly, by modifying the extent of surface water/groundwater exchange. This study illustrates that multiple mechanisms interact in a dynamic way to create spatial heterogeneity in riverine ecosystems, and provides a means to detect spatial self-organization against physical template heterogeneity as a dominant driver of spatial patterns. PMID:28559326

Evidence for self-organization in determining spatial patterns of stream nutrients, despite primacy of the geomorphic template.

PubMed

Dong, Xiaoli; Ruhí, Albert; Grimm, Nancy B

2017-06-13

Nutrients in freshwater ecosystems are highly variable in space and time. Nevertheless, the variety of processes contributing to nutrient patchiness, and the wide range of spatial and temporal scales at which these processes operate, obfuscate how this spatial heterogeneity is generated. Here, we describe the spatial structure of stream nutrient concentration, quantify the relative importance of the physical template and biological processes, and detect and evaluate the role of self-organization in driving such patterns. We examined nutrient spatial patterns in Sycamore Creek, an intermittent desert stream in Arizona that experienced an ecosystem regime shift [from a gravel/algae-dominated to a vascular plant-dominated (hereafter, "wetland") system] in 2000 when cattle grazing ceased. We conducted high-resolution nutrient surveys in surface water along a 10-km stream reach over four visits spanning 18 y (1995-2013) that represent different successional stages and prewetland stage vs. postwetland state. As expected, groundwater upwelling had a major influence on nutrient spatial patterns. However, self-organization realized by the mechanism of spatial feedbacks also was significant and intensified over ecosystem succession, as a resource (nitrogen) became increasingly limiting. By late succession, the effects of internal spatial feedbacks and groundwater upwelling were approximately equal in magnitude. Wetland establishment influenced nutrient spatial patterns only indirectly, by modifying the extent of surface water/groundwater exchange. This study illustrates that multiple mechanisms interact in a dynamic way to create spatial heterogeneity in riverine ecosystems, and provides a means to detect spatial self-organization against physical template heterogeneity as a dominant driver of spatial patterns.

Restriction of the anti-bovine serum albumin response in rabbits immunized with Micrococcus lysodeikticus.

PubMed Central

De Baetselier, P; Hamers-Casterman, C; Van der Loo, W; Hamers, R

1977-01-01

Rabbits capable of producing antibodies of restricted heterogeneity in response to Micrococcus lysodeikticus are equally capable of producing antibodies of restricted heterogeneity to bovine serum albumin. These antibodies are produced when animals are simultaneously injected with micrococcus and BSA and their specificity is restricted to a small number of epitopes. These results suggest that micrococcal vaccines can induce the restriction of heterogeneity in antibodies raised against totally unrelated antigens. Images Figure 4 Figure 5 Figure 2 Figure 6 Figure 7 Figure 8 PMID:71263

An Analytical Investigation of the Robustness and Power of ANCOVA with the Presence of Heterogeneous Regression Slopes.

ERIC Educational Resources Information Center

Hollingsworth, Holly H.

This study shows that the test statistic for Analysis of Covariance (ANCOVA) has a noncentral F-districution with noncentrality parameter equal to zero if and only if the regression planes are homogeneous and/or the vector of overall covariate means is the null vector. The effect of heterogeneous regression slope parameters is to either increase…

Nonclassical Kinetics of Clonal yet Heterogeneous Enzymes.

PubMed

Park, Seong Jun; Song, Sanggeun; Jeong, In-Chun; Koh, Hye Ran; Kim, Ji-Hyun; Sung, Jaeyoung

2017-07-06

Enzyme-to-enzyme variation in the catalytic rate is ubiquitous among single enzymes created from the same genetic information, which persists over the lifetimes of living cells. Despite advances in single-enzyme technologies, the lack of an enzyme reaction model accounting for the heterogeneous activity of single enzymes has hindered a quantitative understanding of the nonclassical stochastic outcome of single enzyme systems. Here we present a new statistical kinetics and exactly solvable models for clonal yet heterogeneous enzymes with possibly nonergodic state dynamics and state-dependent reactivity, which enable a quantitative understanding of modern single-enzyme experimental results for the mean and fluctuation in the number of product molecules created by single enzymes. We also propose a new experimental measure of the heterogeneity and nonergodicity for a system of enzymes.

Halving It All: How Equally Shared Parenting Works.

ERIC Educational Resources Information Center

Deutsch, Francine M.

Noting that details of everyday life contribute to parental equality or inequality, this qualitative study focused on how couples transformed parental roles to create truly equal families. Participating in the study were 88 couples in 4 categories, based on division of parental responsibilities: equal sharers, 60-40 couples, 75-25 couples, and…

Functional Heterogeneity and Senior Management Team Effectiveness

ERIC Educational Resources Information Center

Benoliel, Pascale; Somech, Anit

2016-01-01

Purpose: There has been an increasing trend toward the creation of senior management teams (SMTs) which are characterized by a high degree of functional heterogeneity. Although such teams may create better linkages to information, along with the benefits of functional heterogeneity comes the potential for conflicts that stem from the value…

Sequential, progressive, equal-power, reflective beam-splitter arrays

NASA Astrophysics Data System (ADS)

Manhart, Paul K.

2017-11-01

The equations to calculate equal-power reflectivity of a sequential series of beam splitters is presented. Non-sequential optical design examples are offered for uniform illumination using diode lasers. Objects created using Boolean operators and Swept Surfaces can create objects capable of reflecting light into predefined elevation and azimuth angles. Analysis of the illumination patterns for the array are also presented.

On the evolution of dispersal via heterogeneity in spatial connectivity

PubMed Central

Henriques-Silva, Renato; Boivin, Frédéric; Calcagno, Vincent; Urban, Mark C.; Peres-Neto, Pedro R.

2015-01-01

Dispersal has long been recognized as a mechanism that shapes many observed ecological and evolutionary processes. Thus, understanding the factors that promote its evolution remains a major goal in evolutionary ecology. Landscape connectivity may mediate the trade-off between the forces in favour of dispersal propensity (e.g. kin-competition, local extinction probability) and those against it (e.g. energetic or survival costs of dispersal). It remains, however, an open question how differing degrees of landscape connectivity may select for different dispersal strategies. We implemented an individual-based model to study the evolution of dispersal on landscapes that differed in the variance of connectivity across patches ranging from networks with all patches equally connected to highly heterogeneous networks. The parthenogenetic individuals dispersed based on a flexible logistic function of local abundance. Our results suggest, all else being equal, that landscapes differing in their connectivity patterns will select for different dispersal strategies and that these strategies confer a long-term fitness advantage to individuals at the regional scale. The strength of the selection will, however, vary across network types, being stronger on heterogeneous landscapes compared with the ones where all patches have equal connectivity. Our findings highlight how landscape connectivity can determine the evolution of dispersal strategies, which in turn affects how we think about important ecological dynamics such as metapopulation persistence and range expansion. PMID:25673685

Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport

NASA Astrophysics Data System (ADS)

Rod, Kenton; Um, Wooyong; Chun, Jaehun; Wu, Ning; Yin, Xialong; Wang, Guohui; Neeves, Keith

2018-06-01

A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d-1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500-600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500-600 μm and 300-400 μm). A chemical heterogeneity was created using 25% of the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500-600 μm). Input solution with 0.5 mM CsI and 50 mg L-1 colloids (1-μm diameter SiO2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.

SOA formation from partitioning and heterogeneous reactions: model study in the presence of inorganic species.

PubMed

Jang, Myoseon; Czoschke, Nadine M; Northcross, Amanda L; Cao, Gang; Shaof, David

2006-05-01

A predictive model for secondary organic aerosol (SOA) formation by both partitioning and heterogeneous reactions was developed for SOA created from ozonolysis of alpha-pinene in the presence of preexisting inorganic seed aerosols. SOA was created in a 2 m3 polytetrafluoroethylene film indoor chamber under darkness. Extensive sets of SOA experiments were conducted varying humidity, inorganic seed compositions comprising of ammonium sulfate and sulfuric acid, and amounts of inorganic seed mass. SOA mass was decoupled into partitioning (OM(P)) and heterogeneous aerosol production (OM(H)). The reaction rate constant for OM(H) production was subdivided into three categories (fast, medium, and slow) to consider different reactivity of organic products for the particle phase heterogeneous reactions. The influence of particle acidity on reaction rates was treated in a previous semiempirical model. Model OM(H) was developed with medium and strong acidic seed aerosols, and then extrapolated to OM(H) in weak acidic conditions, which are more relevant to atmospheric aerosols. To demonstrate the effects of preexisting glyoxal derivatives (e.g., glyoxal hydrate and dimer) on OM(H), SOA was created with a seed mixture comprising of aqueous glyoxal and inorganic species. Our results show that heterogeneous SOA formation was also influenced by preexisting reactive glyoxal derivatives.

Differentiated Teaching & Learning in Heterogeneous Classrooms: Strategies for Meeting the Needs of All Students.

ERIC Educational Resources Information Center

Kronberg, Robi; York-Barr, Jennifer; Arnold, Kathy; Gombos, Shawn; Truex, Sharon; Vallejo, Barb; Stevenson, Jane

This guide provides conceptual as well as practical information for meeting the needs of all learners in heterogeneous classrooms. The first six sections discuss the growing heterogeneity in today's classrooms, the rationale for differentiated teaching and learning, the changing roles of teachers and students, the importance of creating classroom…

Heterogeneity in Health Care Computing Environments

PubMed Central

Sengupta, Soumitra

1989-01-01

This paper discusses issues of heterogeneity in computer systems, networks, databases, and presentation techniques, and the problems it creates in developing integrated medical information systems. The need for institutional, comprehensive goals are emphasized. Using the Columbia-Presbyterian Medical Center's computing environment as the case study, various steps to solve the heterogeneity problem are presented.

Landscapes of facilitation: how self-organized patchiness of aquatic macrophytes promotes diversity in streams.

PubMed

Cornacchia, Loreta; van de Koppel, Johan; van der Wal, Daphne; Wharton, Geraldene; Puijalon, Sara; Bouma, Tjeerd J

2018-04-01

Spatial heterogeneity plays a crucial role in the coexistence of species. Despite recognition of the importance of self-organization in creating environmental heterogeneity in otherwise uniform landscapes, the effects of such self-organized pattern formation in promoting coexistence through facilitation are still unknown. In this study, we investigated the effects of pattern formation on species interactions and community spatial structure in ecosystems with limited underlying environmental heterogeneity, using self-organized patchiness of the aquatic macrophyte Callitriche platycarpa in streams as a model system. Our theoretical model predicted that pattern formation in aquatic vegetation - due to feedback interactions between plant growth, water flow and sedimentation processes - could promote species coexistence, by creating heterogeneous flow conditions inside and around the plant patches. The spatial plant patterns predicted by our model agreed with field observations at the reach scale in naturally vegetated rivers, where we found a significant spatial aggregation of two macrophyte species around C. platycarpa. Field transplantation experiments showed that C. platycarpa had a positive effect on the growth of both beneficiary species, and the intensity of this facilitative effect was correlated with the heterogeneous hydrodynamic conditions created within and around C. platycarpa patches. Our results emphasize the importance of self-organized patchiness in promoting species coexistence by creating a landscape of facilitation, where new niches and facilitative effects arise in different locations. Understanding the interplay between competition and facilitation is therefore essential for successful management of biodiversity in many ecosystems. © 2018 The Authors Ecology published by Wiley Periodicals, Inc. on behalf of Ecological Society of America.

A novel method of estimation of lipophilicity using distance-based topological indices: dominating role of equalized electronegativity.

PubMed

Agrawal, Vijay K; Gupta, Madhu; Singh, Jyoti; Khadikar, Padmakar V

2005-03-15

Attempt is made to propose yet another method of estimating lipophilicity of a heterogeneous set of 223 compounds. The method is based on the use of equalized electronegativity along with topological indices. It was observed that excellent results are obtained in multiparametric regression upon introduction of indicator parameters. The results are discussed critically on the basis various statistical parameters.

Environmental heterogeneity, dispersal mode, and co-occurrence in stream macroinvertebrates

PubMed Central

Heino, Jani

2013-01-01

Both environmental heterogeneity and mode of dispersal may affect species co-occurrence in metacommunities. Aquatic invertebrates were sampled in 20–30 streams in each of three drainage basins, differing considerably in environmental heterogeneity. Each drainage basin was further divided into two equally sized sets of sites, again differing profoundly in environmental heterogeneity. Benthic invertebrate data were divided into three groups of taxa based on overland dispersal modes: passive dispersers with aquatic adults, passive dispersers with terrestrial winged adults, and active dispersers with terrestrial winged adults. The co-occurrence of taxa in each dispersal mode group, drainage basin, and heterogeneity site subset was measured using the C-score and its standardized effect size. The probability of finding high levels of species segregation tended to increase with environmental heterogeneity across the drainage basins. These patterns were, however, contingent on both dispersal mode and drainage basin. It thus appears that environmental heterogeneity and dispersal mode interact in affecting co-occurrence in metacommunities, with passive dispersers with aquatic adults showing random patterns irrespective of environmental heterogeneity, and active dispersers with terrestrial winged adults showing increasing segregation with increasing environmental heterogeneity. PMID:23467653

Impact of an equality constraint on the class-specific residual variances in regression mixtures: A Monte Carlo simulation study.

PubMed

Kim, Minjung; Lamont, Andrea E; Jaki, Thomas; Feaster, Daniel; Howe, George; Van Horn, M Lee

2016-06-01

Regression mixture models are a novel approach to modeling the heterogeneous effects of predictors on an outcome. In the model-building process, often residual variances are disregarded and simplifying assumptions are made without thorough examination of the consequences. In this simulation study, we investigated the impact of an equality constraint on the residual variances across latent classes. We examined the consequences of constraining the residual variances on class enumeration (finding the true number of latent classes) and on the parameter estimates, under a number of different simulation conditions meant to reflect the types of heterogeneity likely to exist in applied analyses. The results showed that bias in class enumeration increased as the difference in residual variances between the classes increased. Also, an inappropriate equality constraint on the residual variances greatly impacted on the estimated class sizes and showed the potential to greatly affect the parameter estimates in each class. These results suggest that it is important to make assumptions about residual variances with care and to carefully report what assumptions are made.

Equality of Opportunity: Perspectives and Possibilities.

ERIC Educational Resources Information Center

Greene, Maxine

A survey of the concept of equality in American thought and literature reveals varying attitudes about socioeconomic opportunities and the function of education. In 1848, de Tocqueville foresaw that industrialization would create a manufacturing aristocracy which would be a threat to the equality demonstrated in agrarian America. During the…

Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport

DOE PAGES

Rod, Kenton; Um, Wooyong; Chun, Jaehun; ...

2018-03-31

A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d -1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500–600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500–600 μm and 300–400 μm). A chemical heterogeneity was created using 25% ofmore » the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500–600 μm). Input solution with 0.5 mM CsI and 50 mg L -1 colloids (1-μm diameter SiO 2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.« less

Effect of chemical and physical heterogeneities on colloid-facilitated cesium transport

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

Rod, Kenton; Um, Wooyong; Chun, Jaehun

A set of column experiments was conducted to investigate the chemical and physical heterogeneity effect on colloid facilitated transport under slow pore velocity conditions. Pore velocities were kept below 100 cm d -1 for all experiments. Glass beads were packed into columns establishing four different conditions: 1) homogeneous, 2) mixed physical heterogeneity, 3) sequentially layered physical heterogeneity, and 4) chemical heterogeneity. The homogeneous column was packed with glass beads (diameter 500–600 μm), and physical heterogeneities were created by sequential layering or mixing two sizes of glass bead (500–600 μm and 300–400 μm). A chemical heterogeneity was created using 25% ofmore » the glass beads coated with hydrophobic molecules (1H-1H-2H-2H-perfluorooctyltrichlorosilane) mixed with 75% pristine glass beads (all 500–600 μm). Input solution with 0.5 mM CsI and 50 mg L -1 colloids (1-μm diameter SiO 2) was pulsed into columns under saturated conditions. The physical heterogeneity in the packed glass beads retarded the transport of colloids compared to homogeneous (R = 25.0), but showed only slight differences between sequentially layered (R = 60.7) and mixed heterogeneity(R = 62.4). The column with the chemical, hydrophobic/hydrophilic, heterogeneity removed most of the colloids from the input solution. All column conditions stripped Cs from colloids onto the column matrix of packed glass beads.« less

[Quantitative characterization of nuclear polymorphism of the epithelial cells in fibroadenomatosis and cancer of the breast].

PubMed

Ganina, K P; Petunin, Iu I; Timoshenko, Ia G

1989-01-01

A method for quantitative analysis of epithelial cell nuclear polymorphism was suggested, viz. identification of general statistical population using Petunin's criterion. This criterion was employed to assess heterogeneity of visible surface of interphase epithelial cell nuclei and to assay nuclear DNA level in fibroadenomatous hyperplasia and cancer of the breast. Heterogeneity index (h), alongside with other parameters, appeared useful for quantitative assessment of the disease: heterogeneity index values ranging 0.1-0.4 point to pronounced heterogeneity of epithelial cell nucleus surface and DNA level, and are suggestive of malignant transformation of tissue, whereas benign proliferation of the epithelium is usually characterized by 0.4 less than h less than or equal to 0.9.

Heterogeneous Risk Perceptions: The Case of Poultry Meat Purchase Intentions in Finland

PubMed Central

Heikkilä, Jaakko; Pouta, Eija; Forsman-Hugg, Sari; Mäkelä, Johanna

2013-01-01

This study focused on the heterogeneity of consumer reactions, measured through poultry meat purchase intentions, when facing three cases of risk. The heterogeneity was analysed by latent class logistic regression that included all three risk cases. Approximately 60% of the respondents belonged to the group of production risk avoiders, in which the intention to purchase risk food was significantly lower than in the second group of risk neutrals. In addition to socio-demographic variables, the purchase intentions were statistically associated with several attitude-based variables. We highlighted some policy implications of the heterogeneity. Overall, the study demonstrated that risk matters to consumers, not all risk is equal, and consumer types react somewhat differently to different types of risk. PMID:24157513

Homogeneous-heterogeneous reactions in curved channel with porous medium

NASA Astrophysics Data System (ADS)

Hayat, T.; Ayub, Sadia; Alsaedi, A.

2018-06-01

Purpose of the present investigation is to examine the peristaltic flow through porous medium in a curved conduit. Problem is modeled for incompressible electrically conducting Ellis fluid. Influence of porous medium is tackled via modified Darcy's law. The considered model utilizes homogeneous-heterogeneous reactions with equal diffusivities for reactant and autocatalysis. Constitutive equations are formulated in the presence of viscous dissipation. Channel walls are compliant in nature. Governing equations are modeled and simplified under the assumptions of small Reynolds number and large wavelength. Graphical results for velocity, temperature, heat transfer coefficient and homogeneous-heterogeneous reaction parameters are examined for the emerging parameters entering into the problem. Results reveal an activation in both homogenous-heterogenous reaction effect and heat transfer rate with increasing curvature of the channel.

Israel's Gender Equality Policy in Education: Revolution or Containment?

ERIC Educational Resources Information Center

Eden, Devorah

2000-01-01

Examines Israel's policy of gender equality in education, discussing: social and economic forces that created the demand for equality; political processes for implementing the policy; and policy content. Data from interviews and document reviews indicate that the policy was devised to address concerns of high-tech industries and women,…

Enantiomerically enriched, polycrystalline molecular sieves

DOE PAGES

Brand, Stephen K.; Schmidt, Joel E.; Deem, Michael W.; ...

2017-05-01

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. For this study, enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electronmore » microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).« less

Enantiomerically enriched, polycrystalline molecular sieves

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

Brand, Stephen K.; Schmidt, Joel E.; Deem, Michael W.

Zeolite and zeolite-like molecular sieves are being used in a large number of applications such as adsorption and catalysis. Achievement of the long-standing goal of creating a chiral, polycrystalline molecular sieve with bulk enantioenrichment would enable these materials to perform enantioselective functions. Here, we report the synthesis of enantiomerically enriched samples of a molecular sieve. For this study, enantiopure organic structure directing agents are designed with the assistance of computational methods and used to synthesize enantioenriched, polycrystalline molecular sieve samples of either enantiomer. Computational results correctly predicted which enantiomer is obtained, and enantiomeric enrichment is proven by high-resolution transmission electronmore » microscopy. The enantioenriched and racemic samples of the molecular sieves are tested as adsorbents and heterogeneous catalysts. The enantioenriched molecular sieves show enantioselectivity for the ring opening reaction of epoxides and enantioselective adsorption of 2-butanol (the R enantiomer of the molecular sieve shows opposite and approximately equal enantioselectivity compared with the S enantiomer of the molecular sieve, whereas the racemic sample of the molecular sieve shows no enantioselectivity).« less

Pre-set extrusion bioprinting for multiscale heterogeneous tissue structure fabrication.

PubMed

Kang, Donggu; Ahn, Geunseon; Kim, Donghwan; Kang, Hyun-Wook; Yun, Seokhwan; Yun, Won-Soo; Shim, Jin-Hyung; Jin, Songwan

2018-06-06

Recent advances in three-dimensional bioprinting technology have led to various attempts in fabricating human tissue-like structures. However, current bioprinting technologies have limitations for creating native tissue-like structures. To resolve these issues, we developed a new pre-set extrusion bioprinting technique that can create heterogeneous, multicellular, and multimaterial structures simultaneously. The key to this ability lies in the use of a precursor cartridge that can stably preserve a multimaterial with a pre-defined configuration that can be simply embedded in a syringe-based printer head. The multimaterial can be printed and miniaturized through a micro-nozzle without conspicuous deformation according to the pre-defined configuration of the precursor cartridge. Using this system, we fabricated heterogeneous tissue-like structures such as spinal cords, hepatic lobule, blood vessels, and capillaries. We further obtained a heterogeneous patterned model that embeds HepG2 cells with endothelial cells in a hepatic lobule-like structure. In comparison with homogeneous and heterogeneous cell printing, the heterogeneous patterned model showed a well-organized hepatic lobule structure and higher enzyme activity of CYP3A4. Therefore, this pre-set extrusion bioprinting method could be widely used in the fabrication of a variety of artificial and functional tissues or organs.

CT Identification and Fractal Characterization of 3-D Propagation and Distribution of Hydrofracturing Cracks in Low-Permeability Heterogeneous Rocks

NASA Astrophysics Data System (ADS)

Liu, Peng; Ju, Yang; Gao, Feng; Ranjith, Pathegama G.; Zhang, Qianbing

2018-03-01

Understanding and characterization of the three-dimensional (3-D) propagation and distribution of hydrofracturing cracks in heterogeneous rock are key for enhancing the stimulation of low-permeability petroleum reservoirs. In this study, we investigated the propagation and distribution characteristics of hydrofracturing cracks, by conducting true triaxial hydrofracturing tests and computed tomography on artificial heterogeneous rock specimens. Silica sand, Portland cement, and aedelforsite were mixed to create artificial heterogeneous rock specimens using the data of mineral compositions, coarse gravel distribution, and mechanical properties that were measured from the natural heterogeneous glutenite cores. To probe the effects of material heterogeneity on hydrofracturing cracks, the artificial homogenous specimens were created using the identical matrix compositions of the heterogeneous rock specimens and then fractured for comparison. The effects of horizontal geostress ratio on the 3-D growth and distribution of cracks during hydrofracturing were examined. A fractal-based method was proposed to characterize the complexity of fractures and the efficiency of hydrofracturing stimulation of heterogeneous media. The material heterogeneity and horizontal geostress ratio were found to significantly influence the 3-D morphology, growth, and distribution of hydrofracturing cracks. A horizontal geostress ratio of 1.7 appears to be the upper limit for the occurrence of multiple cracks, and higher ratios cause a single crack perpendicular to the minimum horizontal geostress component. The fracturing efficiency is associated with not only the fractured volume but also the complexity of the crack network.

The biogeochemical heterogeneity of tropical forests.

PubMed

Townsend, Alan R; Asner, Gregory P; Cleveland, Cory C

2008-08-01

Tropical forests are renowned for their biological diversity, but also harbor variable combinations of soil age, chemistry and susceptibility to erosion or tectonic uplift. Here we contend that the combined effects of this biotic and abiotic diversity promote exceptional biogeochemical heterogeneity at multiple scales. At local levels, high plant diversity creates variation in chemical and structural traits that affect plant production, decomposition and nutrient cycling. At regional levels, myriad combinations of soil age, soil chemistry and landscape dynamics create variation and uncertainty in limiting nutrients that do not exist at higher latitudes. The effects of such heterogeneity are not well captured in large-scale estimates of tropical ecosystem function, but we suggest new developments in remote sensing can help bridge the gap.

THERMAL HETEROGENEITY, STREAM CHANNEL MORPHOLOGY, AND SALMONID ABUNDANCE IN NORTHEASTERN OREGON STREAMS

EPA Science Inventory

Heterogeneity in stream water temperatures created by local influx of cooler subsurface waters into geomorphically complex stream channels was associated with increased abundance of rainbow trout (Oncorhynchus mykiss) and chinook salmon (O. tshawytscha) in northeastern Oregon. Th...

Job Segregation and Wage Discrimination under Title VII and the Equal Pay Act.

ERIC Educational Resources Information Center

Lorber, Lawrence Z.

1980-01-01

Questions whether the Equal Employment Opportunity Commission, or any other agency of the federal government, has the authority to create guidelines for personnel evaluation in the private sector. (Author/IRT)

Women at Work: The Myth of Equal Opportunity.

ERIC Educational Resources Information Center

Piercy, Day; Krieter, Nancy

The advances women have made in the past decade have created the myth that women have achieved equal opportunity in the job market. In reality, the opposite is true. The current economic status of women demonstrates the need for strict enforcement of equal opportunity laws. Department of Labor data indicate that the wage gap between men and women…

Office of Equal Opportunity Programs

NASA Technical Reports Server (NTRS)

Chin, Jennifer L.

2004-01-01

The NASA Glenn Office of Equal Opportunity Programs works to provide quality service for all programs and/or to assist the Center in becoming a model workplace. During the summer of 2004, I worked with Deborah Cotleur along with other staff members to create and modify customer satisfaction surveys. This office aims to assist in developing a model workplace by providing functions as a change agent to the center by serving as an advisor to management to ensure equity throughout the Center. In addition, the office serves as a mediator for the Center in addressing issues and concerns. Lastly, the office provides assistance to employees to enable attainment of personal and organizational goals. The Office of Equal Opportunities is a staff office which reports and provides advice to the Center Director and Executive Leadership, implements laws, regulations, and presidential executive orders, and provides center wide leadership and assistance to NASA GRC employees. Some of the major responsibilities of the office include working with the discrimination complaints program, special emphasis programs (advisory groups), management support, monitoring and evaluation, contract compliance, and community outreach. During my internship in this office, my main objective was to create four customer satisfaction surveys based on EO retreats, EO observances, EO advisory boards, and EO mediation/counseling. I created these surveys after conducting research on past events and surveys as well as similar survey research created and conducted by other NASA centers, program for EO Advisory group members, leadership training sessions for supervisors, preventing sexual harassment training sessions, and observance events. I also conducted research on the style and format from feedback surveys from the Marshall Equal Opportunity website, the Goddard website, and the main NASA website. Using the material from the Office of Equal Opportunity Programs at Glenn Research Center along with my previous research, I created four customer satisfaction surveys. Additional information is included in the original extended abstract.

Assembly of tissue engineered blood vessels with spatially-controlled heterogeneities.

PubMed

Strobel, Hannah A; Hookway, Tracy; Piola, Marco; Fiore, Gianfranco Beniamino; Soncini, Monica; Alsberg, Eben; Rolle, Marsha

2018-05-04

Tissue-engineered human blood vessels may enable in vitro disease modeling and drug screening to accelerate advances in vascular medicine. Existing methods for tissue engineered blood vessel (TEBV) fabrication create homogenous tubes not conducive to modeling the focal pathologies characteristic of vascular disease. We developed a system for generating self-assembled human smooth muscle cell ring-units, which were fused together into TEBVs. The goal of this study was to assess the feasibility of modular assembly and fusion of ring building units to fabricate spatially-controlled, heterogeneous tissue tubes. We first aimed to enhance fusion and reduce total culture time, and determined that reducing ring pre-culture duration improved tube fusion. Next, we incorporated electrospun polymer ring units onto tube ends as reinforced extensions, which allowed us to cannulate tubes after only 7 days of fusion, and culture tubes with luminal flow in a custom bioreactor. To create focal heterogeneities, we incorporated gelatin microspheres into select ring units during self-assembly, and fused these rings between ring units without microspheres. Cells within rings maintained their spatial position within tissue tubes after fusion. This work describes a platform approach for creating modular TEBVs with spatially-defined structural heterogeneities, which may ultimately be applied to mimic focal diseases such as intimal hyperplasia or aneurysm.

Laboratory Evidence of Strength Recovery of Healed Faults

NASA Astrophysics Data System (ADS)

Masuda, K.

2015-12-01

Fault zones consist of a fault core and a surrounding damage zone. Fault zones are typically characterized by the presence of many healed surfaces, the strength of which is unknown. If a healed fault recovers its strength such that its cohesion is equal to or greater than that of the host rock, repeated cycles of fracture and healing may be one mechanism producing wide fault zones. I present laboratory evidence supporting the strength recovery of healed fault surface, obtained by AE monitoring, strain measurements and X-ray CT techniques. The loading experiment was performed with a specimen collected from an exhumed fault zone. Healed surfaces of the rock sample were interpreted to be parallel to slip surfaces. The specimen was a cylinder with 50 mm diameter and 100 mm long. The long axis of the specimen was inclined with respect to the orientation of the healed surfaces. The compression test used a constant loading rate under 50 MPa of confining pressure. Macroscopic failure occurred when the applied differential stress reached 439 MPa. The macro-fracture surface created during the experiment was very close to the preexisting plane. The AE hypocenters closely match the locations of the preexisting healed surface and the new fault plane. The experiment also revealed details of the initial stage of fault development. The new fault zone developed near, but not precisely on the preexisting healed fault plane. An area of heterogeneous structure where stress appears to have concentrated, was where the AEs began, and it was also where the fracture started. This means that the healed surface was not a weak surface and that healing strengthened the fault such that its cohesion was equal to or greater than that of the intact host rock. These results suggest that repeated cycles of fracture and healing may be the main mechanism creating wide fault zones with multiple fault cores and damage zones.

Universal Design and LGBTQ (Lesbian, Gay, Transgender, Bisexual, and Queer) Issues: Creating Equal Access and Opportunities for Success

ERIC Educational Resources Information Center

Daniels, Jennifer R.; Geiger, Tracy J.

2010-01-01

The authors extend the ideals set forth by the universal design (UD) framework seeking to include the unique needs of students in the lesbian, gay, bisexual, transgender, and queer (LGBTQ) community. Universal design is a philosophy that, when applied to higher education, constitutes acceptance of, equal access for, and equal opportunities for…

Induced spatial heterogeneity in forest canopies: responses of small mammals.

Treesearch

A.B. Carey

2001-01-01

We hypothesized that creating a mosaic of interspersed patches of different densities of canopy trees in a second-growth Douglas-fir (Pseudotsuga menziesiz) forest would accelerate development of biocomplexity (diversity in ecosystem structure, composition, and processes) by promoting spatial heterogeneity in understory, midstory, and canopy,...

Designed to Fail: A Novel Mode of Collagen Fibril Disruption and Its Relevance to Tissue Toughness

PubMed Central

Veres, Samuel P.; Lee, J. Michael

2012-01-01

Collagen fibrils are nanostructured biological cables essential to the structural integrity of many of our tissues. Consequently, understanding the structural basis of their robust mechanical properties is of great interest. Here we present what to our knowledge is a novel mode of collagen fibril disruption that provides new insights into both the structure and mechanics of native collagen fibrils. Using enzyme probes for denatured collagen and scanning electron microscopy, we show that mechanically overloading collagen fibrils from bovine tail tendons causes them to undergo a sequential, two-stage, selective molecular failure process. Denatured collagen molecules—meaning molecules with a reduced degree of time-averaged helicity compared to those packed in undamaged fibrils—were first created within kinks that developed at discrete, repeating locations along the length of fibrils. There, collagen denaturation within the kinks was concentrated within certain subfibrils. Additional denatured molecules were then created along the surface of some disrupted fibrils. The heterogeneity of the disruption within fibrils suggests that either mechanical load is not carried equally by a fibril's subcomponents or that the subcomponents do not possess homogenous mechanical properties. Meanwhile, the creation of denatured collagen molecules, which necessarily involves the energy intensive breaking of intramolecular hydrogen bonds, provides a physical basis for the toughness of collagen fibrils. PMID:22735538

Convective mixing in vertically-layered porous media: The linear regime and the onset of convection

NASA Astrophysics Data System (ADS)

Ghorbani, Zohreh; Riaz, Amir; Daniel, Don

2017-08-01

We study the effect of permeability heterogeneity on the stability of gravitationally unstable, transient, diffusive boundary layers in porous media. Permeability is taken to vary periodically in the horizontal plane normal to the direction of gravity. In contrast to the situation for vertical permeability variation, the horizontal perturbation structures are multimodal. We therefore use a two-dimensional quasi-steady eigenvalue analysis as well as a complementary initial value problem to investigate the stability behavior in the linear regime, until the onset of convection. We find that thick permeability layers enhance instability compared with thin layers when heterogeneity is increased. On the contrary, for thin layers the instability is weakened progressively with increasing heterogeneity to the extent that the corresponding homogeneous case is more unstable. For high levels of heterogeneity, we find that a small change in the permeability field results in large variations in the onset time of convection, similar to the instability event in the linear regime. However, this trend does not persist unconditionally because of the reorientation of vorticity pairs due to the interaction of evolving perturbation structures with heterogeneity. Consequently, an earlier onset of instability does not necessarily imply an earlier onset of convection. A resonant amplification of instability is observed within the linear regime when the dominant perturbation mode is equal to half the wavenumber of permeability variation. On the other hand, a substantial damping occurs when the perturbation mode is equal to the harmonic and sub-harmonic components of the permeability wavenumber. The phenomenon of such harmonic interactions influences both the onset of instability as well as the onset of convection.

Convective mixing in vertically-layered porous media: The linear regime and the onset of convection

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

Ghorbani, Zohreh; Riaz, Amir; Daniel, Don

In this paper, we study the effect of permeability heterogeneity on the stability of gravitationally unstable, transient, diffusive boundary layers in porous media. Permeability is taken to vary periodically in the horizontal plane normal to the direction of gravity. In contrast to the situation for vertical permeability variation, the horizontal perturbation structures are multimodal. We therefore use a two-dimensional quasi-steady eigenvalue analysis as well as a complementary initial value problem to investigate the stability behavior in the linear regime, until the onset of convection. We find that thick permeability layers enhance instability compared with thin layers when heterogeneity is increased.more » On the contrary, for thin layers the instability is weakened progressively with increasing heterogeneity to the extent that the corresponding homogeneous case is more unstable. For high levels of heterogeneity, we find that a small change in the permeability field results in large variations in the onset time of convection, similar to the instability event in the linear regime. However, this trend does not persist unconditionally because of the reorientation of vorticity pairs due to the interaction of evolving perturbation structures with heterogeneity. Consequently, an earlier onset of instability does not necessarily imply an earlier onset of convection. A resonant amplification of instability is observed within the linear regime when the dominant perturbation mode is equal to half the wavenumber of permeability variation. On the other hand, a substantial damping occurs when the perturbation mode is equal to the harmonic and sub-harmonic components of the permeability wavenumber. Finally, the phenomenon of such harmonic interactions influences both the onset of instability as well as the onset of convection.« less

Convective mixing in vertically-layered porous media: The linear regime and the onset of convection

DOE PAGES

Ghorbani, Zohreh; Riaz, Amir; Daniel, Don

2017-08-02

In this paper, we study the effect of permeability heterogeneity on the stability of gravitationally unstable, transient, diffusive boundary layers in porous media. Permeability is taken to vary periodically in the horizontal plane normal to the direction of gravity. In contrast to the situation for vertical permeability variation, the horizontal perturbation structures are multimodal. We therefore use a two-dimensional quasi-steady eigenvalue analysis as well as a complementary initial value problem to investigate the stability behavior in the linear regime, until the onset of convection. We find that thick permeability layers enhance instability compared with thin layers when heterogeneity is increased.more » On the contrary, for thin layers the instability is weakened progressively with increasing heterogeneity to the extent that the corresponding homogeneous case is more unstable. For high levels of heterogeneity, we find that a small change in the permeability field results in large variations in the onset time of convection, similar to the instability event in the linear regime. However, this trend does not persist unconditionally because of the reorientation of vorticity pairs due to the interaction of evolving perturbation structures with heterogeneity. Consequently, an earlier onset of instability does not necessarily imply an earlier onset of convection. A resonant amplification of instability is observed within the linear regime when the dominant perturbation mode is equal to half the wavenumber of permeability variation. On the other hand, a substantial damping occurs when the perturbation mode is equal to the harmonic and sub-harmonic components of the permeability wavenumber. Finally, the phenomenon of such harmonic interactions influences both the onset of instability as well as the onset of convection.« less

Do Differences in Exposures Explain the Observed Heterogeneity in PM2.5 - Mortality Associations across U.S. cities?

EPA Science Inventory

This analysis evaluates exposure factors as potential determinants of the heterogeneity in city-specific associations between PM2.5 and mortality. Exposure factor variables were created based on housing characteristics, commuting patterns, heating fuel usage, and climatic factors...

Spatial heterogeneity lowers rather than increases host-parasite specialization.

PubMed

Hesse, E; Best, A; Boots, M; Hall, A R; Buckling, A

2015-09-01

Abiotic environmental heterogeneity can promote the evolution of diverse resource specialists, which in turn may increase the degree of host-parasite specialization. We coevolved Pseudomonas fluorescens and lytic phage ϕ2 in spatially structured populations, each consisting of two interconnected subpopulations evolving in the same or different nutrient media (homogeneous and heterogeneous environments, respectively). Counter to the normal expectation, host-parasite specialization was significantly lower in heterogeneous compared with homogeneous environments. This result could not be explained by dispersal homogenizing populations, as this would have resulted in the heterogeneous treatments having levels of specialization equal to or greater than that of the homogeneous environments. We argue that selection for costly generalists is greatest when the coevolving species are exposed to diverse environmental conditions and that this can provide an explanation for our results. A simple coevolutionary model of this process suggests that this can be a general mechanism by which environmental heterogeneity can reduce rather than increase host-parasite specialization. © 2015 The Authors. J. EVOL. BIOL. Journal of Evolutionary Biology Published by John Wiley & Sons Ltd on Behalf of European Society for Evolutionary Biology.

DOE Energy Frontiers Research Center for Heterogeneous Functional Materials; the “HeteroFoaM Center”

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

Reifsnider, Kenneth Leonard

Synopsis of five year accomplishments: Devices that convert and store energy are generally made from heterogeneous constituent materials that act and interact to selectively conduct, transport, and separate mass, heat, and charge. Controlling these actions and interactions enables the technical breakthroughs that have made fuel cells, batteries, and solid state membranes, for example, essential parts of our society. In the biological sense, these materials are ‘vascular’ rather than primitive ‘cellular’ materials, in which the arrangements and configurations of the constituents (including their void phases) play essential and definitive roles in their functional capabilities. In 2009 a group of investigators, withmore » lifetime investments of effort in the understanding of heterogeneous materials, recognized that the design of such material systems is not an optimization problem as such. Local interactions of the constituents create “emergent” properties and responses that are not part of the formal set of constituent characteristics, in much the same sense that society and culture is created by the group interactions of the people involved. The design of emergent properties is an open question in all formal science, but for energy materials the lack of this foundation science relegates development tasks to Edisonian trial and error, with anecdotal success and frequent costly failures. That group defined, for the first time, multi-scale heterogeneous functional materials with functional disordered and void phase regions as “HeteroFoaM,” and formed the first multidisciplinary research team to define and codify the foundation science of that material class. The primary goal of the HeteroFoaM Center was, and is, to create and establish the multi-scale fundamental knowledge and related methodology required for the rational and systematic multiphysics design of heterogeneous functional materials and their interfaces and surfaces for applications in energy transformation and storage. The scope of the HeteroFoaM center was focused on the discovery and development of the control science of key phenomena across multiple length scales that create functionality in heterogeneous materials and their structured interfaces, boundaries, and surfaces for applications in energy technologies. The HeteroFoaM Center defined a critical path and established an essential foundation for progress in the field of heterogeneous functional materials. Perhaps the single most important element of progress was the establishment of the capability to design, characterize, and model heterogeneous functional materials at the conformal level, i.e., for a limited set of material systems, the HeteroFoaM team defined how to control the order / disorder at the atomic level, the surfaces, and the interfaces for selected constituent morphologies, and to use multiphysical models to explain the remarkable property variations resulting from that control science for several heterogeneous material systems. For those cases we defined “meso-structures” (at various scales) where the interactive physics of constituent phases acted to create emergent properties, e.g., strongly emergent mixed conductor behavior and ionic transport. The general approach used by this EFRC is shown in Fig. 1. The HeteroFoaM Center created the genre of Heterogeneous Functional Materials with functional surfaces and interfaces (including void phases) called HeteroFoaM as a science platform to enable rational analysis and design of functional material systems by focusing on the meso-interactions that drive emergent response. The team firmly established this approach with over 180 archival publications (see “Publications” section), 7 patent applications, and over 100 invited lectures in 15 countries on this topic, enabled by building a remarkably effective and uniquely coherent research team. Indeed, our team was our principal strength; this problem eluded solution earlier because such a team was not available.« less

"Kill the Baby": Making All Things Equal.

ERIC Educational Resources Information Center

Agne, Karen

1999-01-01

Suggests that the trend toward detracking and inclusion in schools is socio-politically motivated. Rebuts arguments that tracking is racist and damages self-esteem and identifies harmful effects of heterogeneous grouping. Concludes that tracking and ability grouping have a place in education. (SK)

The effect of heterogeneous defectors on the evolution of public cooperation

NASA Astrophysics Data System (ADS)

Chen, Tong; Hu, Xuezhi; Wang, Yongjie; Wang, Le

2018-06-01

In recent years,more and more private capital join the construction of cultural facilities and the organization of cultural activities in China. Actually, the organization of cultural activities by crowd-funding mechanism is a kind of multi-player game. Not all players who donate different amount of money are real cooperators. In fact, some cunning defectors may donate a little money to avoid the gossip and punishment. This part of people are very tricky. They could be seen as heterogeneous defectors. The role of heterogeneous defectors is investigated in cooperative behaviors of complex social network. Numerical results show that heterogeneous defectors could be a buffer for maintaining the public pool when synergy factor is low in public goods game (PGG). It is relatively easy to be cooperators for heterogeneous defectors when synergy factor is high in PGG. To better improve cooperation, punishment towards heterogeneous defectors and complete defectors is introduced. We are glad to find that when the defectors' loss is equal to or larger than the altruistic cooperators' punishment cost, the mechanism could make great effect. In addition, the role of heterogeneous defectors depends on the relationship between the punishment cost and the defectors' loss.

A New Coarsening Operator for the Optimal Preconditioning of the Dual and Primal Domain Decomposition Methods: Application to Problems with Severe Coefficient Jumps

NASA Technical Reports Server (NTRS)

Farhat, Charbel; Rixen, Daniel

1996-01-01

We present an optimal preconditioning algorithm that is equally applicable to the dual (FETI) and primal (Balancing) Schur complement domain decomposition methods, and which successfully addresses the problems of subdomain heterogeneities including the effects of large jumps of coefficients. The proposed preconditioner is derived from energy principles and embeds a new coarsening operator that propagates the error globally and accelerates convergence. The resulting iterative solver is illustrated with the solution of highly heterogeneous elasticity problems.

Modelling heterogeneity variances in multiple treatment comparison meta-analysis--are informative priors the better solution?

PubMed

Thorlund, Kristian; Thabane, Lehana; Mills, Edward J

2013-01-11

Multiple treatment comparison (MTC) meta-analyses are commonly modeled in a Bayesian framework, and weakly informative priors are typically preferred to mirror familiar data driven frequentist approaches. Random-effects MTCs have commonly modeled heterogeneity under the assumption that the between-trial variance for all involved treatment comparisons are equal (i.e., the 'common variance' assumption). This approach 'borrows strength' for heterogeneity estimation across treatment comparisons, and thus, ads valuable precision when data is sparse. The homogeneous variance assumption, however, is unrealistic and can severely bias variance estimates. Consequently 95% credible intervals may not retain nominal coverage, and treatment rank probabilities may become distorted. Relaxing the homogeneous variance assumption may be equally problematic due to reduced precision. To regain good precision, moderately informative variance priors or additional mathematical assumptions may be necessary. In this paper we describe four novel approaches to modeling heterogeneity variance - two novel model structures, and two approaches for use of moderately informative variance priors. We examine the relative performance of all approaches in two illustrative MTC data sets. We particularly compare between-study heterogeneity estimates and model fits, treatment effect estimates and 95% credible intervals, and treatment rank probabilities. In both data sets, use of moderately informative variance priors constructed from the pair wise meta-analysis data yielded the best model fit and narrower credible intervals. Imposing consistency equations on variance estimates, assuming variances to be exchangeable, or using empirically informed variance priors also yielded good model fits and narrow credible intervals. The homogeneous variance model yielded high precision at all times, but overall inadequate estimates of between-trial variances. Lastly, treatment rankings were similar among the novel approaches, but considerably different when compared with the homogenous variance approach. MTC models using a homogenous variance structure appear to perform sub-optimally when between-trial variances vary between comparisons. Using informative variance priors, assuming exchangeability or imposing consistency between heterogeneity variances can all ensure sufficiently reliable and realistic heterogeneity estimation, and thus more reliable MTC inferences. All four approaches should be viable candidates for replacing or supplementing the conventional homogeneous variance MTC model, which is currently the most widely used in practice.

Origins and implications of pluripotent stem cell variability and heterogeneity

PubMed Central

Cahan, Patrick; Daley, George Q.

2014-01-01

Pluripotent stem cells constitute a platform to model disease and developmental processes and can potentially be used in regenerative medicine. However, not all pluripotent cell lines are equal in their capacity to differentiate into desired cell types in vitro. Genetic and epigenetic variations contribute to functional variability between cell lines and heterogeneity within clones. These genetic and epigenetic variations could ‘lock’ the pluripotency network resulting in residual pluripotent cells or alter the signalling response of developmental pathways leading to lineage bias. The molecular contributors to functional variability and heterogeneity in both embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are only beginning to emerge, yet they are crucial to the future of the stem cell field. PMID:23673969

Long-life physical property preservation and postendodontic rehabilitation with the Composipost.

PubMed

Duret, B; Duret, F; Reynaud, M

1996-01-01

Most coronal radicular reconstructions are made of cast inlay core metals or prefabricated posts covered in composite. The differences in the mechanical properties of these elements create a heterogeneous mass with inconsistent mechanical behavior. Studies using the Finite Element Method have shown the biomechanical disturbances caused by the inclusion of materials with a modulus of elasticity that is superior to that of dentine (i.e., nickel, chrome, zircon, etc). The use of materials with a modulus of elasticity close to that of dentine does not disturb the flow of stress inside the root. To our knowledge, only a composite material structured with programmable mechanical properties would be capable of producing both high mechanical performance and a modulus of elasticity adapted to dentine values. The C-POST, made of carbon epoxy, accommodates the demands of the dentine, as well as the in vitro stress linked to the prosthesis. The internal structure, consisting of long high-performance carbon fibers, unidirectionally and equally stretched, confers a totally original behavior that is adapted to clinical objectives. In addition, the C-POST has a fracture resistance superior to most metals.

The Global Inventor Gap: Distribution and Equality of World-Wide Inventive Effort, 1990–2010

PubMed Central

Toivanen, Hannes; Suominen, Arho

2015-01-01

Applying distance-to-frontier analysis, we have used 2.9 million patents and population data to assess whether the relative capacity of world countries and major regions to create new knowledge and technology has become globally more equal or less equal between 1990 and 2010. We show with the Gini coefficient that the global distribution of inventors has become more equal between major countries and regions. However, this trend has been largely due to the improved performance of only two major countries, China and India. The worst performing regions, totalling a population of almost 2 billion, are actually falling behind. Our results suggest that substantial parts of the global population have fallen further behind countries at the global frontier in their ability to create new knowledge and inventions, and that the catch-up among the least developed and middle-income countries is highly uneven, prompting questions about the nature and future of the global knowledge economy. PMID:25849202

Engineering the architectural diversity of heterogeneous metallic nanocrystals.

PubMed

Yu, Yue; Zhang, Qingbo; Xie, Jianping; Lee, Jim Yang

2013-01-01

Similar to molecular engineering where structural diversity is used to create more property variations for application explorations, the architectural engineering of heterogeneous metallic nanocrystals (HMNCs) can likewise increase the versatility of metallic nanocrystals (NCs). Here we present a synthesis strategy capable of engineering the architectural diversity of HMNCs through rational and independent programming of every architecture-determining element, that is, the shape and size of the component NCs and their spatial arrangement. The strategy is based on the galvanic replacement reaction of a self-sustaining layer formed by underpotential deposition on a polyhedral NC. The selective deposition of satellite NCs on specific site of the central NC is realized by creating a geometry-dependent heterogeneous electron distribution. This site-selective deposition approach is applicable to central NCs in various polyhedral shapes and sizes. The satellite NCs can further develop their own shape and size through crystal growth kinetics control.

Rights to Equality for Disabled Persons under Federal and State Law

ERIC Educational Resources Information Center

Stapleton, Margaret

1976-01-01

Legislation has mandated equal opportunity in American society for persons with handicaps, creating mechanisms for ending discrimination against them. Access to education, employment, public transportation vehicles and other facilities, and community living situations is specifically guaranteed in federal legislation. State statutes and municipal…

Moving beyond gender: processes that create relationship equality.

PubMed

Knudson-Martin, Carmen; Mahoney, Anne Rankin

2005-04-01

Equality is related to relationship success, yet few couples achieve it. In this qualitative study, we examine how couples with children in two time cohorts (1982 and 2001) moved toward equality. The analysis identifies three types of couples: Postgender, gender legacy, and traditional. Movement toward equality is facilitated by: (a) Stimulus for change, including awareness of gender, commitment to family and work, and situational pressures; and (b) patterns that promote change, including active negotiation, challenges to gender entitlement, development of new competencies, and mutual attention to relationship and family tasks. Implications for practice are discussed.

Should heterogeneity be the basis for conservation? Grassland bird response to fire and grazing

USGS Publications Warehouse

Fuhlendorf, S.D.; Harrell, W.C.; Engle, David M.; Hamilton, R.G.; Davis, C.A.; Leslie, David M.

2006-01-01

In tallgrass prairie, disturbances such as grazing and fire can generate patchiness across the landscape, contributing to a shifting mosaic that presumably enhances biodiversity. Grassland birds evolved within the context of this shifting mosaic, with some species restricted to one or two patch types created under spatially and temporally distinct disturbance regimes. Thus, management-driven reductions in heterogeneity may be partly responsible for declines in numbers of grassland birds. We experimentally altered spatial heterogeneity of vegetation structure within a tallgrass prairie by varying the spatial and temporal extent of fire and by allowing grazing animals to move freely among burned and unburned patches (patch treatment). We contrasted this disturbance regime with traditional agricultural management of the region that promotes homogeneity (traditional treatment). We monitored grassland bird abundance during the breeding seasons of 2001-2003 to determine the influence of altered spatial heterogeneity on the grassland bird community. Focal disturbances of patch burning and grazing that shifted through the landscape over several years resulted in a more heterogeneous pattern of vegetation than uniform application of fire and grazing. Greater spatial heterogeneity in vegetation provided greater variability in the grassland bird community. Some bird species occurred in greatest abundance within focally disturbed patches, while others occurred in relatively undisturbed patches in our patch treatment. Henslow's Sparrow, a declining species, occurred only within the patch treatment. Upland Sandpiper and some other species were more abundant on recently disturbed patches within the same treatment. The patch burn treatment created the entire gradient of vegetation structure required to maintain a suite of grassland bird species that differ in habitat preferences. Our study demonstrated that increasing spatial and temporal heterogeneity of disturbance in grasslands increases variability in vegetation structure that results in greater variability at higher trophic levels. Thus, management that creates a shifting mosaic using spatially and temporally discrete disturbances in grasslands can be a useful tool in conservation. In the case of North American tallgrass prairie, discrete fires that capitalize on preferential grazing behavior of large ungulates promote a shifting mosaic of habitat types that maintain biodiversity and agricultural productivity. ?? 2006 by the Ecological Society of America.

49 CFR 701.6 - Release and processing procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... requests will be handled according to the date that the FOIA request was initially received. (d) Creating a... existing records. The cost of creating or compiling such a record may not be charged to the requester unless the fee for creating the record is equal to or less than the fee that would be charged for...

Beyond Diversity and Inclusion: Creating a Social Justice Agenda in the Classroom

ERIC Educational Resources Information Center

Lerner, Justin E.; Fulambarker, Anjali

2018-01-01

A social justice classroom agenda relies on the ability of educators to create a space free from microaggressions that can be strengthened through an approach of cultural humility. Utilizing Bonnycastle's social justice continuum, this article explores how to create a classroom grounded in social equality and guided by social work values to foster…

Why power matters: creating a foundation of mutual support in couple relationships.

PubMed

Knudson-Martin, Carmen

2013-03-01

Research shows that equal power helps couples create intimacy and relationship success. However, though couples increasingly desire equal relationships, cultural models of mutual support are not well developed. Clinicians often approach heterosexual couple therapy as though partners are inherently equal, thus reinforcing unacknowledged gender inequities. This article examines research that shows why power imbalances are destructive to intimate relationships and focuses on four gender-related aspects of mutual support: (a) shared relational responsibility, (b) mutual vulnerability, (c) mutual attunement, and (d) shared influence. Case examples illustrate how socio-emotional attunement, interrupting the flow of power, and introducing alternative relational experience help couple therapists identify and address power disparities in these important relational processes. Encouraging the powerful person to take relational initiative and introducing alternative gender discourse are especially important. © FPI, Inc.

The Enduring Legacy of "Rodriguez": Creating New Pathways to Equal Educational Opportunity

ERIC Educational Resources Information Center

Ogletree, Charles J., Jr., Ed.; Robinson, Kimberly Jenkins, Ed.

2015-01-01

In this ambitious volume, leading legal and educational scholars examine "San Antonio Independent School District v. Rodriguez" (1973), the landmark US Supreme Court decision that held that the Constitution does not guarantee equality of educational opportunity. Charles J. Ogletree, Jr., and Kimberly Jenkins Robinson have brought…

Discipline: Impact on Access to Equal Educational Opportunities

ERIC Educational Resources Information Center

Joubert, Rika; de Waal, Elda; Rossouw, JP

2004-01-01

Complying with the founding values (human dignity, equality and freedom) of the South African Constitution is one of the most important challenges of creating and maintaining a safe, disciplined environment where effective teaching and learning can take place. All school principals, educators and school governing bodies--bearing in mind the…

Smoothly varying in-plane stiffness heterogeneity evaluated under uniaxial tensile stress

Treesearch

J.M. Considine; F. Pierron; K.T. Turner; P. Lava; X. Tang

2017-01-01

Identification of spatially varying stiffness is a challenging, but important, research topic in the mechanics of materials and can provide the necessary information for material suitability, damage, and process control, especially for high‐value applications. One homogeneous and 3 heterogeneous virtual field method (VFM) formulations were used to create a methodology...

A Method To Ensure Heterogeneous Mixing of Grade 9 Classes.

ERIC Educational Resources Information Center

Brydges, Bruce

This paper presents outcomes of a practicum that was designed to address a need that was created when the Ministry of Education in Ontario, Canada, mandated that all grade 9 classes be "destreamed." A review of educational literature found no methods for ensuring that classes are truly heterogeneously mixed. The practicum was designed to…

Plant succession on gopher mounds in Western Cascade meadows: consequences for species diversity and heterogeneity

Treesearch

Chad C. Jones; Charles B. Halpern; Jessica Niederer

2008-01-01

Pocket gophers have the potential to alter the dynamics of grasslands by creating mounds that bury existing vegetation and locally reset succession. Gopher mounds may provide safe sites for less competitive species, potentially increasing both species diversity and vegetation heterogeneity (spatial variation in species composition). We compared species composition,...

Ownership and ecosystem as sources of spatial heterogeneity in a forested landscape, Wisconsin, USA

Treesearch

Thomas R. Crow; George E. Host; David J. Mladenoff

1999-01-01

The interaction between physical environment and land ownership in creating spatial heterogeneity was studied in largely forested landscapes of northern Wisconsin, USA. A stratified random approach was used in which 2500-ha plots representing two ownerships (National Forest and private non-industrial) were located within two regional ecosystems (extremely well-drained...

Heterogeneous propellant internal ballistics: criticism and regeneration

NASA Astrophysics Data System (ADS)

Glick, R. L.

2011-10-01

Although heterogeneous propellant and its innately nondeterministic, chemically discrete morphology dominates applications, ballisticcharacterization deterministic time-mean burning rate and acoustic admittance measures' absence of explicit, nondeterministic information requires homogeneous propellant with a smooth, uniformly regressing burning surface: inadequate boundary conditions for heterogeneous propellant grained applications. The past age overcame this dichotomy with one-dimensional (1D) models and empirical knowledge from numerous, adequately supported motor developments and supplementary experiments. However, current cost and risk constraints inhibit this approach. Moreover, its fundamental science approach is more sensitive to incomplete boundary condition information (garbage-in still equals garbage-out) and more is expected. This work critiques this situation and sketches a path forward based on enhanced ballistic and motor characterizations in the workplace and approximate model and apparatus developments mentored by CSAR DNS capabilities (or equivalent).

Novel cyclone empirical pressure drop and emissions with heterogeneous particulate

USDA-ARS?s Scientific Manuscript database

New cyclone designs equally effective at controlling emissions that have smaller pressure losses would reduce both the financial and the environmental cost of procuring electricity. Tests were conducted with novel and industry standard 30.5 cm diameter cyclones at inlet velocities from 8 to 18 m s-...

Interactive Groups: Examining and Interrogating Issues of Heterogeneity and Accountability

ERIC Educational Resources Information Center

Frost, Gail; Connolly, Maureen

2009-01-01

Teachers and learners alike bring past experiences into present teaching and learning contexts. Group work is an experience that carries equal measures of joyful anticipation and mournful trepidation. Learners typically experience group work as an uneven distribution of time, competence, and accountability, and seem to have lingering memories of…

What Next? Promoting Alternatives to Ability Grouping.

ERIC Educational Resources Information Center

Wheelock, Anne; Hawley, Willis D.

1993-01-01

Suggests ways to eliminate ability grouping in the schools, and explores new alternatives to improve schooling for all students. Specific guidelines are given for the development of academically and racially heterogeneous schooling. The elimination of grouping practices that deny equal access to education is a goal worth pursuing. (SLD)

How Social Preferences Shape Incentives in (Experimental) Markets for Credence Goods.

PubMed

Kerschbamer, Rudolf; Sutter, Matthias; Dulleck, Uwe

2017-03-01

Credence goods markets suffer from inefficiencies caused by superior information of sellers about the surplus-maximising quality. While standard theory predicts that equal mark-up prices solve the credence goods problem if customers can verify the quality received, experimental evidence indicates the opposite. We identify a lack of robustness with respect to heterogeneity in social preferences as a possible cause of this and conduct new experiments that allow for parsimonious identification of sellers' social preference types. Our results confirm the assumed heterogeneity in social preferences and provide strong support for our explanation of the failure of verifiability to increase efficiency.

Modeling early in situ wetting of a compacted bentonite buffer installed in low permeable crystalline bedrock

NASA Astrophysics Data System (ADS)

Dessirier, B.; Frampton, A.; Fransson, À.; Jarsjö, J.

2016-08-01

The repository concept for geological disposal of spent nuclear fuel in Sweden and Finland is planned to be constructed in sparsely fractured crystalline bedrock and with an engineered bentonite buffer to embed the waste canisters. An important stage in such a deep repository is the postclosure phase following the deposition and the backfilling operations when the initially unsaturated buffer material gets hydrated by the groundwater delivered by the natural bedrock. We use numerical simulations to interpret observations on buffer wetting gathered during an in situ campaign, the Bentonite Rock Interaction Experiment, in which unsaturated bentonite columns were introduced into deposition holes in the floor of a 417 m deep tunnel at the Äspö Hard Rock Laboratory in Sweden. Our objectives are to assess the performance of state-of-the-art flow models in reproducing the buffer wetting process and to investigate to which extent dependable predictions of buffer wetting times and saturation patterns can be made based on information collected prior to buffer insertion. This would be important for preventing insertion into unsuitable bedrock environments. Field data and modeling results indicate the development of a de-saturated zone in the rock and show that in most cases, the presence or absence of fractures and flow heterogeneity are more important factors for correct wetting predictions than the total inflow. For instance, for an equal open-hole inflow value, homogeneous inflow yields much more rapid buffer wetting than cases where fractures are represented explicitly thus creating heterogeneous inflow distributions.

Mobility of Protozoa through Narrow Channels

PubMed Central

Wang, Wei; Shor, Leslie M.; LeBoeuf, Eugene J.; Wikswo, John P.; Kosson, David S.

2005-01-01

Microbes in the environment are profoundly affected by chemical and physical heterogeneities occurring on a spatial scale of millimeters to micrometers. Physical refuges are critical for maintaining stable bacterial populations in the presence of high predation pressure by protozoa. The effects of microscale heterogeneity, however, are difficult to replicate and observe using conventional experimental techniques. The objective of this research was to investigate the effect of spatial constraints on the mobility of six species of marine protozoa. Microfluidic devices were created with small channels similar in size to pore spaces in soil or sediment systems. Individuals from each species of protozoa tested were able to rapidly discover and move within these channels. The time required for locating the channel entrance from the source well increased with protozoan size and decreased with channel height. Protozoa of every species were able to pass constrictions with dimensions equal to or smaller than the individual's unconstrained cross-sectional area. Channel geometry was also an important factor affecting protozoan mobility. Linear rates of motion for various species of protozoa varied by channel size. In relatively wide channels, typical rates of motion were 300 to 500 μm s−1 (or about 1 m per hour). As the channel dimensions decreased, however, motilities slowed more than an order of magnitude to 20 μm s−1. Protozoa were consistently observed to exhibit several strategies for successfully traversing channel reductions. The empirical results and qualitative observations resulting from this research help define the physical limitations on protozoan grazing, a critical process affecting microbes in the environment. PMID:16085857

Bounding the heterogeneous gas uptake on aerosols and ground using resistance model

NASA Astrophysics Data System (ADS)

Su, H.; Li, M.; Cheng, Y.

2017-12-01

Heterogeneous uptake on aerosols and ground are potential important atmospheric sinks for gases. Different schemes have been used to characterize the dry deposition and heterogeneous aerosol gas uptake, although they share similar characteristics. In this work, we propose a unified resistance model to compare the uptake flux on both ground and aerosols, to identify the dominate heterogeneous process within the planetary boundary layer (PBL). The Gamma(eq) is introduced to represent the reactive uptake coefficient on aerosols when these two processes are equally important. It's shown that Gamma(eq) is proportional to the dry deposition velocity, inversely proportional to aerosol surface area concentration. Under typical regional background condition, Gamma(eq) vary from 1x10-5 to 4x10-4 with gas species, land-use type and season, which indicates that aerosol gas uptake should be included in atmospheric models when uptake coefficient higher than 10-5. We address the importance of heterogeneous gas uptake on aerosols over ground especially for ozone uptake on liquid organic aerosols and for marine PBL atmosphere.

Heterogeneous delays making parents synchronized: A coupled maps on Cayley tree model

NASA Astrophysics Data System (ADS)

Singh, Aradhana; Jalan, Sarika

2014-06-01

We study the phase synchronized clusters in the diffusively coupled maps on the Cayley tree networks for heterogeneous delay values. Cayley tree networks comprise of two parts: the inner nodes and the boundary nodes. We find that heterogeneous delays lead to various cluster states, such as; (a) cluster state consisting of inner nodes and boundary nodes, and (b) cluster state consisting of only boundary nodes. The former state may comprise of nodes from all the generations forming self-organized cluster or nodes from few generations yielding driven clusters depending upon on the parity of heterogeneous delay values. Furthermore, heterogeneity in delays leads to the lag synchronization between the siblings lying on the boundary by destroying the exact synchronization among them. The time lag being equal to the difference in the delay values. The Lyapunov function analysis sheds light on the destruction of the exact synchrony among the last generation nodes. To the end we discuss the relevance of our results with respect to their applications in the family business as well as in understanding the occurrence of genetic diseases.

Regional gas transport in the heterogeneous lung during oscillatory ventilation

PubMed Central

Herrmann, Jacob; Tawhai, Merryn H.

2016-01-01

Regional ventilation in the injured lung is heterogeneous and frequency dependent, making it difficult to predict how an oscillatory flow waveform at a specified frequency will be distributed throughout the periphery. To predict the impact of mechanical heterogeneity on regional ventilation distribution and gas transport, we developed a computational model of distributed gas flow and CO2 elimination during oscillatory ventilation from 0.1 to 30 Hz. The model consists of a three-dimensional airway network of a canine lung, with heterogeneous parenchymal tissues to mimic effects of gravity and injury. Model CO2 elimination during single frequency oscillation was validated against previously published experimental data (Venegas JG, Hales CA, Strieder DJ, J Appl Physiol 60: 1025–1030, 1986). Simulations of gas transport demonstrated a critical transition in flow distribution at the resonant frequency, where the reactive components of mechanical impedance due to airway inertia and parenchymal elastance were equal. For frequencies above resonance, the distribution of ventilation became spatially clustered and frequency dependent. These results highlight the importance of oscillatory frequency in managing the regional distribution of ventilation and gas exchange in the heterogeneous lung. PMID:27763872

Competence development for the promotion of gender equality in development cooperation: the case of the Swedish International Development Cooperation Agency (SIDA).

PubMed

Hannan-andersson, C

1997-01-01

The Swedish International Development Cooperation Agency (SIDA) has created an Action Program for Promoting Equality Between Women and Men in Partner Countries that emphasizes competency development as a means of achieving gender equality. Competency development goes beyond formal training and utilizes existing entry points while creating innovative ones. SIDA's partnership approach requires clear delineation of roles for SIDA personnel and partner countries, with SIDA 1) applying a gender perspective to assessments, 2) initiating a constructive dialogue about gender equality if needed, 3) assessing the need for gender equality promoting competency development, 4) studying the local context, and 5) developing effective local networks. In addition, the needs of different groups within SIDA should be met with appropriate competency development inputs while SIDA continues support to competency development in partner countries by developing local capacity for gender training and gender sensitization at the regional and national levels. At SIDA, gender training has evolved since 1989 to its current focus on the practical and concrete challenges facing participants. In addition, departments and divisions conduct sector- and issue-specific training, and gender equality is integrated in all SIDA training activities on every topic. The challenges for future competency development are to 1) increase the number of men involved in provision of competency development inputs, 2) improve competency at embassy and field levels, and 3) improve competency in policy dialogues.

The One World of Working Women. Monograph No. 1.

ERIC Educational Resources Information Center

Nelson, Anne H.

Women of many nations, particularly the industrialized countries, are achieving greater opportunity and equality in the working world. The rate at which women are joining the work force has confounded all predictions and created unexpected difficulties in securing equal pay and access to jobs and training. The most direct discrimination, separate…

Gender-heterogeneous working groups produce higher quality science.

PubMed

Campbell, Lesley G; Mehtani, Siya; Dozier, Mary E; Rinehart, Janice

2013-01-01

Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index). While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science.

Gender-Heterogeneous Working Groups Produce Higher Quality Science

PubMed Central

Campbell, Lesley G.; Mehtani, Siya; Dozier, Mary E.; Rinehart, Janice

2013-01-01

Here we present the first empirical evidence to support the hypothesis that a gender-heterogeneous problem-solving team generally produced journal articles perceived to be higher quality by peers than a team comprised of highly-performing individuals of the same gender. Although women were historically underrepresented as principal investigators of working groups, their frequency as PIs at the National Center for Ecological Analysis and Synthesis is now comparable to the national frequencies in biology and they are now equally qualified, in terms of their impact on the accumulation of ecological knowledge (as measured by the h-index). While women continue to be underrepresented as working group participants, peer-reviewed publications with gender-heterogeneous authorship teams received 34% more citations than publications produced by gender-uniform authorship teams. This suggests that peers citing these publications perceive publications that also happen to have gender-heterogeneous authorship teams as higher quality than publications with gender uniform authorship teams. Promoting diversity not only promotes representation and fairness but may lead to higher quality science. PMID:24205372

Modelling heterogeneity variances in multiple treatment comparison meta-analysis – Are informative priors the better solution?

PubMed Central

2013-01-01

Background Multiple treatment comparison (MTC) meta-analyses are commonly modeled in a Bayesian framework, and weakly informative priors are typically preferred to mirror familiar data driven frequentist approaches. Random-effects MTCs have commonly modeled heterogeneity under the assumption that the between-trial variance for all involved treatment comparisons are equal (i.e., the ‘common variance’ assumption). This approach ‘borrows strength’ for heterogeneity estimation across treatment comparisons, and thus, ads valuable precision when data is sparse. The homogeneous variance assumption, however, is unrealistic and can severely bias variance estimates. Consequently 95% credible intervals may not retain nominal coverage, and treatment rank probabilities may become distorted. Relaxing the homogeneous variance assumption may be equally problematic due to reduced precision. To regain good precision, moderately informative variance priors or additional mathematical assumptions may be necessary. Methods In this paper we describe four novel approaches to modeling heterogeneity variance - two novel model structures, and two approaches for use of moderately informative variance priors. We examine the relative performance of all approaches in two illustrative MTC data sets. We particularly compare between-study heterogeneity estimates and model fits, treatment effect estimates and 95% credible intervals, and treatment rank probabilities. Results In both data sets, use of moderately informative variance priors constructed from the pair wise meta-analysis data yielded the best model fit and narrower credible intervals. Imposing consistency equations on variance estimates, assuming variances to be exchangeable, or using empirically informed variance priors also yielded good model fits and narrow credible intervals. The homogeneous variance model yielded high precision at all times, but overall inadequate estimates of between-trial variances. Lastly, treatment rankings were similar among the novel approaches, but considerably different when compared with the homogenous variance approach. Conclusions MTC models using a homogenous variance structure appear to perform sub-optimally when between-trial variances vary between comparisons. Using informative variance priors, assuming exchangeability or imposing consistency between heterogeneity variances can all ensure sufficiently reliable and realistic heterogeneity estimation, and thus more reliable MTC inferences. All four approaches should be viable candidates for replacing or supplementing the conventional homogeneous variance MTC model, which is currently the most widely used in practice. PMID:23311298

Electrokinetically driven microfluidic mixing with patchwise surface heterogeneity and AC applied electric field

NASA Astrophysics Data System (ADS)

Luo, Win-Jet; Yue, Cheng-Feng

2004-12-01

This paper investigates two-dimensional, time-dependent electroosmotic flows driven by an AC electric field via patchwise surface heterogeneities distributed along the microchannel walls. The time-dependent flow fields through the microchannel are simulated for various patchwise heterogeneous surface patterns using the backwards-Euler time stepping numerical method. Different heterogeneous surface patterns are found to create significantly different electrokinetic transport phenomena. It is shown that the presence of oppositely charged surface heterogeneities on the microchannel walls results in the formation of localized flow circulations within the bulk flow. These circulation regions grow and decay periodically in accordance with the applied periodic AC electric field intensity. The circulations provide an effective means of enhancing species mixing in the microchannel. A suitable design of the patchwise heterogeneous surface pattern permits the mixing channel length and the retention time required to attain a homogeneous solution to be reduced significantly.

From motherhood penalties to husband premia: the new challenge for gender equality and family policy, lessons from Norway.

PubMed

Petersen, Trond; Penner, Andrew M; Høgsnes, Geir

2014-03-01

Given the key role that processes occurring in the family play in creating gender inequality, the family is a central focus of policies aimed at creating greater gender equality. We examine how family status affects the gender wage gap using longitudinal matched employer-employee data from Norway, 1979-96, a period with extensive expansion of family policies. The motherhood penalty dropped dramatically from 1979 to 1996. Among men the premia for marriage and fatherhood remained constant. In 1979, the gender wage gap was primarily due to the motherhood penalty, but by 1996 husband premia were more important than motherhood penalties.

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

Kauweloa, K; Gutierrez, A; Bergamo, A

Purpose: There is growing interest about biological effective dose (BED) and its application in treatment plan evaluation due to its stronger correlation with treatment outcome. An approximate biological effective dose (BEDA) equation was introduced to simplify BED calculations by treatment planning systems in multi-phase treatments. The purpose of this work is to reveal its mathematical properties relative to the true, multi-phase BED (BEDT) equation. Methods: The BEDT equation was derived and used to reveal the mathematical properties of BEDA. MATLAB (MathWorks, Natick, MA) was used to simulate and analyze common and extreme clinical multi-phase cases. In those cases, percent errormore » (Perror) and Bland-Altman analysis were used to study the significance of the inaccuracies of BEDA for different combinations of total doses, numbers of fractions, doses per fractions and α over β values. All the calculations were performed on a voxel-basis in order to study how dose distributions would affect the accuracy of BEDA. Results: When the voxel dose-per-fractions (DPF) delivered by both phases are equal, BEDA and BEDT are equal. In heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the imprecision of BEDA is greater. It was shown that as the α over β ratio increased the accuracy of BEDA would improve. Examining twenty-four cases, it was shown that the range of DPF ratios for a 3 Perror varied from 0.32 to 7.50Gy, whereas for Perror of 1 the range varied from 0.50 to 2.96Gy. Conclusion: The DPF between the different phases should be equal in order to render BEDA accurate. OARs typically receive heterogeneous dose distributions hence the probability of equal DPFs is low. Consequently, the BEDA equation should only be used for targets or OARs that receive uniform or very similar dose distributions by the different treatment phases.« less

Social Actions Career Ladder and Utilization Field, AFSCs 734X0A/B, 736XA/B, 737X, 73499, and 73400.

DTIC Science & Technology

1984-11-01

enlisted specialty was composed of three shreds: 734XOA - Social Actions Technician, Equal Opportunity; 734XOB- Social Actions Technician, Drug/Alcohol...and 734X0C - Social Actions Technician, Race Relations. On 30 April 1980, the Equal Opportunity and Race Relations specialties were merged to form...AFS 734X0A - Social Actions Technician, Equal Opportunity/Human Relations. The officer Social Actions utilization field was created on 31 January 1973

Hidden Gains: Effects of Early U.S. Compulsory Schooling Laws on Attendance and Attainment by Social Background

ERIC Educational Resources Information Center

Rauscher, Emily

2014-01-01

Research on early compulsory schooling laws finds minimal effects on attendance but fails to investigate heterogeneous effects. Similarly, research proposes limited contexts in which expansion policies can increase equality but has difficulty separating policy and cohort effects. Capitalizing on within-country variation in timing of early…

On Lateral Viscosity Contrast in the Mantle and the Rheology of Low-Frequency Geodynamics

NASA Technical Reports Server (NTRS)

Ivins, Erik R.; Sammis, Charles G.

1995-01-01

Mantle-wide heterogeneity is largely controlled by deeply penetrating thermal convective currents. These thermal currents are likely to produce significant lateral variation in rheology, and this can profoundly influence overall material behaviour. How thermally related lateral viscosity variations impact models of glacio-isostatic and tidal deformation is largely unknown. An important step towards model improvement is to quantify, or bound, the actual viscosity variations that characterize the mantle. Simple scaling of viscosity to shear-wave velocity fluctuations yields map-views of long- wavelength viscosity variation. These give a general quantitative description and aid in estimating the depth dependence of rheological heterogeneity throughout the mantle. The upper mantle is probably characterized by two to four orders of magnitude variation (peak-to-peak). Discrepant time-scales for rebounding Holocene shorelines of Hudson Bay and southern Iceland are consistent with this characterization. Results are given in terms of a local average viscosity ratio, (Delta)eta(bar)(sub i), of volumetric concentration, phi(sub i). For the upper mantle deeper than 340 km the following reasonable limits are estimated for (delta)eta(bar) approx. equal 10(exp -2): 0.01 less than or equal to phi less than or equal to 0.15. A spectrum of ratios (Delta)eta(bar)(sub i) less than 0.1 at concentration level eta(sub i) approx. equal 10(exp -6) - 10(exp -1) in the lower mantle implies a spectrum of shorter time-scale deformational response modes for second-degree spherical harmonic deformations of the Earth. Although highly uncertain, this spectrum of spatial variation allows a purely Maxwellian viscoelastic rheology simultaneously to explain all solid tidal dispersion phenomena and long-term rebound-related mantle viscosity. Composite theory of multiphase viscoelastic media is used to demonstrate this effect.

Network design for telemedicine--e-health using satellite technology.

PubMed

Graschew, Georgi; Roelofs, Theo A; Rakowsky, Stefan; Schlag, Peter M

2008-01-01

Over the last decade various international Information and Communications Technology networks have been created for a global access to high-level medical care. OP 2000 has designed and validated the high-end interactive video communication system WinVicos especially for telemedical applications, training of the physician in a distributed environment, teleconsultation and second opinion. WinVicos is operated on a workstation (WoTeSa) using standard hardware components and offers a superior image quality at a moderate transmission bandwidth of up to 2 Mbps. WoTeSa / WinVicos have been applied for IP-based communication in different satellite-based telemedical networks. In the DELTASS-project a disaster scenario was analysed and an appropriate telecommunication system for effective rescue measures for the victims was set up and evaluated. In the MEDASHIP project an integrated system for telemedical services (teleconsultation, teleelectro-cardiography, telesonography) on board of cruise ships and ferries has been set up. EMISPHER offers an equal access for most of the countries of the Euro-Mediterranean area to on-line services for health care in the required quality of service. E-learning applications, real-time telemedicine and shared management of medical assistance have been realized. The innovative developments in ICT with the aim of realizing a ubiquitous access to medical resources for everyone at any time and anywhere (u-Health) bear the risk of creating and amplifying a digital divide in the world. Therefore we have analyzed how the objective needs of the heterogeneous partners can be joined with the result that there is a need for real integration of the various platforms and services. A virtual combination of applications serves as the basic idea for the Virtual Hospital. The development of virtual hospitals and digital medicine helps to bridge the digital divide between different regions of the world and enables equal access to high-level medical care. Pre-operative planning, intra-operative navigation and minimally-invasive surgery require a digital and virtual environment supporting the perception of the physician. As data and computing resources in a virtual hospital are distributed over many sites the concept of the Grid should be integrated with other communication networks and platforms.

Sex Equality in Vocational Education: A Chance for Educators to Expand Opportunities for Students.

ERIC Educational Resources Information Center

Schonborn, Barbara G.; O'Neil, Mary L.

Addressed to vocational educators and counselors, this booklet contains four main sections. The first section includes definitions of terms in the area of sex equality in vocational education, an overview of the problems created by sex discrimination, and a discussion of the question: Where does vocational education lead? The second section…

Deferring Virtue: The New Management of Students and the Civic Role of Schools

ERIC Educational Resources Information Center

Ben-Porath, Sigal

2013-01-01

The expectation that schools resuscitate civic virtues and create a vibrant civic and public sphere competes with a more powerful contemporary demand on schools, namely, that they generate equal opportunity and mobility, especially for poor and minority youth. This equal opportunity is framed solely in the context of grades on standardized tests.…

Effects of overstory composition and prescribed fire on fuel loading across a heterogeneous managed landscape in the southeastern USA

Treesearch

Bernard R. Parresol; John I. Blake; Andrew J. Thompson

2012-01-01

In the southeastern USA, land use history, forest management and natural geomorphic features have created heterogeneous fuel loads. This apparent temporal and spatial variation in fuel loads make it difficult to reliably assess potential fire behavior from remotely sensed canopy variables to determine risk and to prescribe treatments. We examined this variation by...

High-throughput imaging of heterogeneous cell organelles with an X-ray laser (CXIDB ID 25)

DOE Data Explorer

Hantke, Max, F.

2014-11-17

Preprocessed detector images that were used for the paper "High-throughput imaging of heterogeneous cell organelles with an X-ray laser". The CXI file contains the entire recorded data - including both hits and blanks. It also includes down-sampled images and LCLS machine parameters. Additionally, the Cheetah configuration file is attached that was used to create the pre-processed data.

Average static stress drops for heterogeneous slip distributions: Comparison of several measures and implications for energy partition in earthquakes

NASA Astrophysics Data System (ADS)

Noda, H.; Lapusta, N.; Kanamori, H.

2010-12-01

Static stress drop is often estimated using the seismic moment and rupture area based on a model for uniform stress drop distribution; we denote this estimate by Δσ_M. Δσ_M is sometimes interpreted as the spatial average of stress change over the ruptured area, denoted here as Δσ_A, and used accordingly, for example, to discuss the relation between recurrence interval and the healing of the frictional surface in a system with one degree of freedom [e.g., Marone, 1998]. Δσ_M is also used to estimate available energy (defined as the strain energy change computed using the final stress state as the reference one) and radiation efficiency [e.g., Venkataraman and Kanamori, 2004]. In this work, we define a stress drop measure, Δσ_E, that would enter the exact computation of available energy and radiation efficiency. The three stress drop measures - Δσ_M that can be estimated from observations, Δσ_A, and Δσ_E - are equal if the static stress change is spatially uniform, and that motivates substituting Δσ_M for the other two quantities in applications. However, finite source inversions suggest that the stress change is heterogeneous in natural earthquakes [e.g., Bouchon, 1997]. Since Δσ_M is the average of stress change weighted by slip distribution due to a uniform stress drop [Madariaga, 1979], Δσ_E is the average of stress change weighted by actual slip distribution in the event (this work), and Δσ_A is the simple spatial average of stress change, the three measures should, in general, be different. Here, we investigate the effect of heterogeneity aiming to understand how to use the seismological estimates of stress drop appropriately. We create heterogeneous slip distributions for both circular and rectangular planar ruptures using the approach motivated by Liu-Zeng et al. [2005] and Lavalleé et al [2005]. We find that, indeed, the three stress drop measures differ in our scenarios. In particular, heterogeneity increases Δσ_E and thus the available energy when the seismic moment (and hence Δσ_M) is preserved. So using Δσ_M instead of Δσ_E would underestimate available energy and hence overestimate radiation efficiency. For a range of parameters, Δσ_E is well-approximated by the seismic estimate Δσ_M if the latter is computed using a modified (decreased) rupture area that excludes low-slipped regions; a qualitatively similar procedure is already being used in practice [Somerville et al, 1999].

Public hospital care: equal for all or equal for some? Evidence from the Philippines.

PubMed

James, Chris D; Peabody, John; Hanson, Kara; Solon, Orville

2015-03-01

In low- and middle-income countries, government budgets are rarely sufficient to cover a public hospital's operating costs. Shortfalls are typically financed through a combination of health insurance contributions and user charges. The mixed nature of this financing arrangement potentially creates financial incentives to treat patients with equal health need unequally. Using data from the Philippines, the authors analyzed whether doctors respond to such incentives. After controlling for a patient's condition, they found that patients using insurance, paying more for hospital accommodation, and being treated in externally monitored hospitals were likely to receive more care. This highlights the worrying possibility that public hospital patients with equal health needs are not always equally treated. © 2011 APJPH.

Quantifying the impact of between-study heterogeneity in multivariate meta-analyses

PubMed Central

Jackson, Dan; White, Ian R; Riley, Richard D

2012-01-01

Measures that quantify the impact of heterogeneity in univariate meta-analysis, including the very popular I2 statistic, are now well established. Multivariate meta-analysis, where studies provide multiple outcomes that are pooled in a single analysis, is also becoming more commonly used. The question of how to quantify heterogeneity in the multivariate setting is therefore raised. It is the univariate R2 statistic, the ratio of the variance of the estimated treatment effect under the random and fixed effects models, that generalises most naturally, so this statistic provides our basis. This statistic is then used to derive a multivariate analogue of I2, which we call . We also provide a multivariate H2 statistic, the ratio of a generalisation of Cochran's heterogeneity statistic and its associated degrees of freedom, with an accompanying generalisation of the usual I2 statistic, . Our proposed heterogeneity statistics can be used alongside all the usual estimates and inferential procedures used in multivariate meta-analysis. We apply our methods to some real datasets and show how our statistics are equally appropriate in the context of multivariate meta-regression, where study level covariate effects are included in the model. Our heterogeneity statistics may be used when applying any procedure for fitting the multivariate random effects model. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22763950

Reporting Heterogeneity and Health Disparities Across Gender and Education Levels: Evidence From Four Countries.

PubMed

Molina, Teresa

2016-04-01

I use anchoring vignettes from Indonesia, the United States, England, and China to study the extent to which differences in self-reported health across gender and education levels can be explained by the use of different response thresholds. To determine whether statistically significant differences between groups remain after adjusting thresholds, I calculate standard errors for the simulated probabilities, largely ignored in previous literature. Accounting for reporting heterogeneity reduces the gender gap in many health domains across the four countries, but to varying degrees. Health disparities across education levels persist and even widen after equalizing thresholds across the two groups.

Influence of wood on invertebrate communities in streams and rivers

Treesearch

Arthur Benke; J. Bruce Wallace

2010-01-01

Wood plays a major role in creating multiple invertebrate habitats in small streams and large rivers. In small streams, wood debris dams are instrumental in creating a step and pool profile of habitats, enhancing habitat heterogeneity, retaining organic matter, and changing current velocity. Beavers can convert sections of free-flowing streams into ponds and wetlands...

Regional gas transport in the heterogeneous lung during oscillatory ventilation.

PubMed

Herrmann, Jacob; Tawhai, Merryn H; Kaczka, David W

2016-12-01

Regional ventilation in the injured lung is heterogeneous and frequency dependent, making it difficult to predict how an oscillatory flow waveform at a specified frequency will be distributed throughout the periphery. To predict the impact of mechanical heterogeneity on regional ventilation distribution and gas transport, we developed a computational model of distributed gas flow and CO 2 elimination during oscillatory ventilation from 0.1 to 30 Hz. The model consists of a three-dimensional airway network of a canine lung, with heterogeneous parenchymal tissues to mimic effects of gravity and injury. Model CO 2 elimination during single frequency oscillation was validated against previously published experimental data (Venegas JG, Hales CA, Strieder DJ, J Appl Physiol 60: 1025-1030, 1986). Simulations of gas transport demonstrated a critical transition in flow distribution at the resonant frequency, where the reactive components of mechanical impedance due to airway inertia and parenchymal elastance were equal. For frequencies above resonance, the distribution of ventilation became spatially clustered and frequency dependent. These results highlight the importance of oscillatory frequency in managing the regional distribution of ventilation and gas exchange in the heterogeneous lung. Copyright © 2016 the American Physiological Society.

The Dilemma and Solutions for the Conflicts between Equality and Excellence in the Massification of Higher Education in Taiwan

ERIC Educational Resources Information Center

Hsiou-Huai, Wang

2012-01-01

Equality and excellence are two core values underlying many educational endeavors; however, they are often in conflict and controversy. This article intends to examine the dilemma created by such controversies in the context of massification of higher education in Taiwan and attempt to provide solutions from both the theoretical and policy…

Equality or Equity, Player or Guardian? The Dutch Government and Its Role in Providing Access Opportunities for Government Sponsored International Secondary Education, 1979-2009

ERIC Educational Resources Information Center

Prickarts, Boris

2010-01-01

This article focuses on the Dutch government's International Baccalaureate (IB) Diploma Programme (DP) Pilot, allowing Dutch pre-university students to take part in the IB DP. Is it likely to create "equal", or rather "equitable", access opportunities for government-sponsored Dutch international secondary schools? The article…

Bayesian Power Prior Analysis and Its Application to Operational Risk and Rasch Model

ERIC Educational Resources Information Center

Zhang, Honglian

2010-01-01

When sample size is small, informative priors can be valuable in increasing the precision of estimates. Pooling historical data and current data with equal weights under the assumption that both of them are from the same population may be misleading when heterogeneity exists between historical data and current data. This is particularly true when…

Pitch and Harmony in Gyorgy Ligeti's "Hamburg Concerto" and "Syzygy" for String Quartet

NASA Astrophysics Data System (ADS)

Corey, Charles

The analysis component of this dissertation focuses on intricate and complex pitch relationships in Gyorgy Ligeti's last work, the Hamburg Concerto. This piece uses two distinct tuning systems---twelve tone equal temperament and just intonation---throughout its seven movements. Often, these two systems are used simultaneously, creating complex harmonic relationships. This combination allows Ligeti to exploit the unique features of each system and explore their relationships to each other. Ligeti's just intonation in the Hamburg Concerto comes mainly from the five French horns, who are instructed to keep their hands out of the bell to allow the instrument to sound its exact harmonics. The horns themselves, however, are tuned to varying different fundamentals, creating a constantly changing series of just-intoned pitches anchored above an equal-tempered bass. This method of generating just-intoned intervals adds a second layer to the relationship between equal temperament and just intonation. This paper focuses on creating ways to understand this relationship, and describing the ramifications of these tunings as they unfold throughout the piece. Ligeti very carefully crafts this work in a way that creates a balance between the systems. Research done at the Paul Sacher Stiftung has uncovered a significant collection of errors in the published score. Clearing up these discrepancies allows for a much more accurate and more informed analysis. Throughout this dissertation, mistakes are corrected, and several aspects of the score are clarified. The tuning systems are described, and a likely tuning scheme for the horns is posited. (The analytical component of the dissertation delves into the many varying intervals which all fit into one interval class---a feature that is best explored when two distinct tuning systems are juxtaposed.) A language is created herein to better understand these pitch relationships that fit neither into equal temperament nor just intonation. The analysis clearly shows that very simple musical intervals turn out to be cornerstones of this piece, traceable throughout the entire Hamburg Concerto. The composition, Syzygy for string quartet, is written in just intonation. Through four movements, the relationships evoked by the titles (always groups of homonyms) are examined and illuminated.

Fine-scale structure of the mid-mantle characterised by global stacks of PP precursors

NASA Astrophysics Data System (ADS)

Bentham, H. L. M.; Rost, S.; Thorne, M. S.

2017-08-01

Subduction zones are likely a major source of compositional heterogeneities in the mantle, which may preserve a record of the subduction history and mantle convection processes. The fine-scale structure associated with mantle heterogeneities can be studied using the scattered seismic wavefield that arrives as coda to or as energy preceding many body wave arrivals. In this study we analyse precursors to PP by creating stacks recorded at globally distributed stations. We create stacks aligned on the PP arrival in 5° distance bins (with range 70-120°) from 600 earthquakes recorded at 193 stations stacking a total of 7320 seismic records. As the energy trailing the direct P arrival, the P coda, interferes with the PP precursors, we suppress the P coda by subtracting a best fitting exponential curve to this energy. The resultant stacks show that PP precursors related to scattering from heterogeneities in the mantle are present for all distances. Lateral variations are explored by producing two regional stacks across the Atlantic and Pacific hemispheres, but we find only negligible differences in the precursory signature between these two regions. The similarity of these two regions suggests that well mixed subducted material can survive at upper and mid-mantle depth. To describe the scattered wavefield in the mantle, we compare the global stacks to synthetic seismograms generated using a Monte Carlo phonon scattering technique. We propose a best-fitting layered heterogeneity model, BRT2017, characterised by a three layer mantle with a background heterogeneity strength (ɛ = 0.8%) and a depth-interval of increased heterogeneity strength (ɛ = 1%) between 1000 km and 1800 km. The scalelength of heterogeneity is found to be 8 km throughout the mantle. Since mantle heterogeneity of 8 km scale may be linked to subducted oceanic crust, the detection of increased heterogeneity at mid-mantle depths could be associated with stalled slabs due to increases in viscosity, supporting recent observations of mantle viscosity increases due to the iron spin transition at depths of ∼1000 km.

Automated solar collector installation design including ability to define heterogeneous design preferences

DOEpatents

Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

2014-04-29

Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre -defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

Automated solar collector installation design including ability to define heterogeneous design preferences

DOEpatents

Wayne, Gary; Frumkin, Alexander; Zaydman, Michael; Lehman, Scott; Brenner, Jules

2013-01-08

Embodiments may include systems and methods to create and edit a representation of a worksite, to create various data objects, to classify such objects as various types of pre-defined "features" with attendant properties and layout constraints. As part of or in addition to classification, an embodiment may include systems and methods to create, associate, and edit intrinsic and extrinsic properties to these objects. A design engine may apply of design rules to the features described above to generate one or more solar collectors installation design alternatives, including generation of on-screen and/or paper representations of the physical layout or arrangement of the one or more design alternatives. Embodiments may also include definition of one or more design apertures, each of which may correspond to boundaries in which solar collector layouts should comply with distinct sets of user-defined design preferences. Distinct apertures may provide heterogeneous regions of collector layout according to the user-defined design preferences.

Environmental structure and competitive scoring advantages in team competitions.

PubMed

Merritt, Sears; Clauset, Aaron

2013-10-29

In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

Darcy-Forchheimer flow with Cattaneo-Christov heat flux and homogeneous-heterogeneous reactions

PubMed Central

Hayat, Tasawar; Haider, Farwa; Alsaedi, Ahmed

2017-01-01

Here Darcy-Forchheimer flow of viscoelastic fluids has been analyzed in the presence of Cattaneo-Christov heat flux and homogeneous-heterogeneous reactions. Results for two viscoelastic fluids are obtained and compared. A linear stretching surface has been used to generate the flow. Flow in porous media is characterized by considering the Darcy-Forchheimer model. Modified version of Fourier's law through Cattaneo-Christov heat flux is employed. Equal diffusion coefficients are employed for both reactants and auto catalyst. Optimal homotopy scheme is employed for solutions development of nonlinear problems. Solutions expressions of velocity, temperature and concentration fields are provided. Skin friction coefficient and heat transfer rate are computed and analyzed. Here the temperature and thermal boundary layer thickness are lower for Cattaneo-Christov heat flux model in comparison to classical Fourier's law of heat conduction. Moreover, the homogeneous and heterogeneous reactions parameters have opposite behaviors for concentration field. PMID:28380014

Environmental structure and competitive scoring advantages in team competitions

NASA Astrophysics Data System (ADS)

Merritt, Sears; Clauset, Aaron

2013-10-01

In most professional sports, playing field structure is kept neutral so that scoring imbalances may be attributed to differences in team skill. It thus remains unknown what impact environmental heterogeneities can have on scoring dynamics or competitive advantages. Applying a novel generative model of scoring dynamics to roughly 10 million team competitions drawn from an online game, we quantify the relationship between the structure within a competition and its scoring dynamics, while controlling the impact of chance. Despite wide structural variations, we observe a common three-phase pattern in the tempo of events. Tempo and balance are highly predictable from a competition's structural features alone and teams exploit environmental heterogeneities for sustained competitive advantage. Surprisingly, the most balanced competitions are associated with specific environmental heterogeneities, not from equally skilled teams. These results shed new light on the design principles of balanced competition, and illustrate the potential of online game data for investigating social dynamics and competition.

Distinct Functional Roles of Cardiac Mitochondrial Subpopulations Revealed by a 3D Simulation Model

PubMed Central

Hatano, Asuka; Okada, Jun-ichi; Washio, Takumi; Hisada, Toshiaki; Sugiura, Seiryo

2015-01-01

Experimental characterization of two cardiac mitochondrial subpopulations, namely, subsarcolemmal mitochondria (SSM) and interfibrillar mitochondria (IFM), has been hampered by technical difficulties, and an alternative approach is eagerly awaited. We previously developed a three-dimensional computational cardiomyocyte model that integrates electrophysiology, metabolism, and mechanics with subcellular structure. In this study, we further developed our model to include intracellular oxygen diffusion, and determined whether mitochondrial localization or intrinsic properties cause functional variations. For this purpose, we created two models: one with equal SSM and IFM properties and one with IFM having higher activity levels. Using these two models to compare the SSM and IFM responses of [Ca2+], tricarboxylic acid cycle activity, [NADH], and mitochondrial inner membrane potential to abrupt changes in pacing frequency (0.25–2 Hz), we found that the reported functional differences between these subpopulations appear to be mostly related to local [Ca2+] heterogeneity, and variations in intrinsic properties only serve to augment these differences. We also examined the effect of hypoxia on mitochondrial function. Under normoxic conditions, intracellular oxygen is much higher throughout the cell than the half-saturation concentration for oxidative phosphorylation. However, under limited oxygen supply, oxygen is mostly exhausted in SSM, leaving the core region in an anoxic condition. Reflecting this heterogeneous oxygen environment, the inner membrane potential continues to decrease in IFM, whereas it is maintained to nearly normal levels in SSM, thereby ensuring ATP supply to this region. Our simulation results provide clues to understanding the origin of functional variations in two cardiac mitochondrial subpopulations and their differential roles in maintaining cardiomyocyte function as a whole. PMID:26039174

Modeling the effects of structure on seismic anisotropy in the Chester gneiss dome, southeast Vermont

NASA Astrophysics Data System (ADS)

Saif, S.; Brownlee, S. J.

2017-12-01

Compositional and structural heterogeneity in the continental crust are factors that contribute to the complex expression of crustal seismic anisotropy. Understanding deformation and flow in the crust using seismic anisotropy has thus proven difficult. Seismic anisotropy is affected by rock microstructure and mineralogy, and a number of studies have begun to characterize the full elastic tensors of crustal rocks in an attempt to increase our understanding of these intrinsic factors. However, there is still a large gap in length-scale between laboratory characterization on the scale of centimeters and seismic wavelengths on the order of kilometers. To address this length-scale gap we are developing a 3D crustal model that will help us determine the effects of rotating laboratory-scale elastic tensors into field-scale structures. The Chester gneiss dome in southeast Vermont is our primary focus. The model combines over 2000 structural data points from field measurements and published USGS structural data with elastic tensors of Chester dome rocks derived from electron backscatter diffraction data. We created a uniformly spaced grid by averaging structural measurements together in equally spaced grid boxes. The surface measurements are then projected into the third dimension using existing subsurface interpretations. A measured elastic tensor for the specific rock type is rotated according to its unique structural input at each point in the model. The goal is to use this model to generate artificial seismograms using existing numerical wave propagation codes. Once completed, the model input can be varied to examine the effects of different subsurface structure interpretations, as well as heterogeneity in rock composition and elastic tensors. Our goal is to be able to make predictions for how specific structures will appear in seismic data, and how that appearance changes with variations in rock composition.

Why 'Optimal' Payment for Healthcare Providers Can Never be Optimal Under Community Rating.

PubMed

Zweifel, Peter; Frech, H E

2016-02-01

This article extends the existing literature on optimal provider payment by accounting for consumer heterogeneity in preferences for health insurance and healthcare. This heterogeneity breaks down the separation of the relationship between providers and the health insurer and the relationship between consumers and the insurer. Both experimental and market evidence for a high degree of heterogeneity are presented. Given heterogeneity, a uniform policy fails to effectively control moral hazard, while incentives for risk selection created by community rating cannot be neutralized through risk adjustment. Consumer heterogeneity spills over into relationships with providers, such that a uniform contract with providers also cannot be optimal. The decisive condition for ensuring optimality of provider payment is to replace community rating (which violates the principle of marginal cost pricing) with risk rating of contributions combined with subsidization targeted at high risks with low incomes.

A Framework for Seamless Interoperation of Heterogeneous Distributed Software Components

DTIC Science & Technology

2005-05-01

interoperability, b) distributed resource discovery, and c) validation of quality requirements. Principles and prototypical systems were created to demonstrate the successful completion of the research.

Dependency of branch diameter growth in young Acer trees on light availability and shoot elongation.

PubMed

Sone, Kosei; Noguchi, Ko; Terashima, Ichiro

2005-01-01

Many biomechanical and theoretical studies have been based on the pipe-model theory, according to which a tree is regarded as an assemblage of pipes, each having the same amount of leaf area or leaf mass. However, the physiological mechanisms underlying the theory have not been extensively examined, particularly at the branch level. We analyzed how branches and trunks thickened in nine young Acer mono Maxim. var. marmoratum (Nichols) Hara f. dissectum (Wesmael) Rehder. and A. rufinerve (Siebold & Zucc.) trees. In particular, we examined the roles of light, allocation of photosynthates and shoot heterogeneity. The cross-sectional area (A) of a branch was proportional to cumulative leaf mass or leaf area of the branch, and cumulative cross-sectional area of the daughter branches (SigmaA) above a branching point was equal to the A of the mother branch. These results indicate the validity of the pipe-model theory. However, the theory was invalid for current-year growth of branch cross-sectional area (DeltaA). The DeltaA/SigmaDeltaA for a branching point was greatest (nearly equal to 1) at the crown surface, decreased with crown depth, and tended to increase again at the trunk base, and DeltaA strongly depended on light interception and the yearly increment of leaves on the branch. We examined factors that influenced DeltaA with multiple regression analysis. The ratio of DeltaA of a branch to branch leaf area depended on both relative irradiance and mean current-year shoot length of the branch, suggesting that diameter growth of a branch is determined by the balance between supply of photosynthates, which depends on light interception by the branch, and demand for photosynthates, which is created by the high cambial activity associated with vigorous shoot elongation.

Testing the impact of morphological rate heterogeneity on ancestral state reconstruction of five floral traits in angiosperms.

PubMed

Reyes, Elisabeth; Nadot, Sophie; von Balthazar, Maria; Schönenberger, Jürg; Sauquet, Hervé

2018-06-21

Ancestral state reconstruction is an important tool to study morphological evolution and often involves estimating transition rates among character states. However, various factors, including taxonomic scale and sampling density, may impact transition rate estimation and indirectly also the probability of the state at a given node. Here, we test the influence of rate heterogeneity using maximum likelihood methods on five binary perianth characters, optimized on a phylogenetic tree of angiosperms including 1230 species sampled from all families. We compare the states reconstructed by an equal-rate (Mk1) and a two-rate model (Mk2) fitted either with a single set of rates for the whole tree or as a partitioned model, allowing for different rates on five partitions of the tree. We find strong signal for rate heterogeneity among the five subdivisions for all five characters, but little overall impact of the choice of model on reconstructed ancestral states, which indicates that most of our inferred ancestral states are the same whether heterogeneity is accounted for or not.

Evolutionary dynamics of incubation periods

PubMed Central

Ottino-Loffler, Bertrand; Scott, Jacob G

2017-01-01

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease. PMID:29266000

Evolutionary dynamics of incubation periods.

PubMed

Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

2017-12-21

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

Cultural Diversity Climate and Psychological Adjustment at School-Equality and Inclusion Versus Cultural Pluralism.

PubMed

Schachner, Maja K; Noack, Peter; Van de Vijver, Fons J R; Eckstein, Katharina

2016-07-01

The present study is concerned with cultural diversity climate at school and how it relates to acculturation orientations and psychological school adjustment of early adolescent immigrants. Specifically, the distinct role of two types of diversity policy is investigated, namely (a) fostering equality and inclusion and (b) acknowledging cultural pluralism. Longitudinal multilevel analyses based on 386 early adolescent immigrant students (Mage  = 10.49 years) in 44 ethnically heterogeneous classrooms in Germany revealed that the manifestations of both types of policies promote psychological school adjustment (i.e., better well-being and fewer psychological and behavioral problems) at the individual level. However, they differ in their effects on acculturation orientations. At the classroom level, equality and inclusion promote assimilation. Implications for research and educational practice are discussed. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Investigating equality: The Rényi spectrum

NASA Astrophysics Data System (ADS)

Eliazar, Iddo

2017-09-01

An equality index is a score quantifying the socioeconomic egalitarianism of the distribution of wealth in human societies; the score takes values in the unit interval, with the unit upper bound characterizing purely communist societies. In this paper we explore the Rényi spectrum, a continuum of equality indices that: (i) is based on the moments of the societies' distributions of wealth; (ii) unifies various measures of socioeconomic inequality, including the Theil and Atkinson indices; (iii) displays a collection of amicable analytic properties; (iv) admits multiple Rényi-divergence representations; and (v) provides a high-resolution gauging of egalitarianism that is way beyond what can be offered by the common-practice measures of socioeconomic inequality, the Gini and Pietra indices. At large, the Rényi spectrum is applicable in the context of any distribution of non-negative sizes with a positive mean-yielding a high-resolution gauging of the distribution's inherent statistical heterogeneity.

Technical Note: A new zeolite PET phantom to test segmentation algorithms on heterogeneous activity distributions featured with ground-truth contours.

PubMed

Soffientini, Chiara D; De Bernardi, Elisabetta; Casati, Rosangela; Baselli, Giuseppe; Zito, Felicia

2017-01-01

Design, realization, scan, and characterization of a phantom for PET Automatic Segmentation (PET-AS) assessment are presented. Radioactive zeolites immersed in a radioactive heterogeneous background simulate realistic wall-less lesions with known irregular shape and known homogeneous or heterogeneous internal activity. Three different zeolite families were evaluated in terms of radioactive uptake homogeneity, necessary to define activity and contour ground truth. Heterogeneous lesions were simulated by the perfect matching of two portions of a broken zeolite, soaked in two different 18 F-FDG radioactive solutions. Heterogeneous backgrounds were obtained with tissue paper balls and sponge pieces immersed into radioactive solutions. Natural clinoptilolite proved to be the most suitable zeolite for the construction of artificial objects mimicking homogeneous and heterogeneous uptakes in 18 F-FDG PET lesions. Heterogeneous backgrounds showed a coefficient of variation equal to 269% and 443% of a uniform radioactive solution. Assembled phantom included eight lesions with volumes ranging from 1.86 to 7.24 ml and lesion to background contrasts ranging from 4.8:1 to 21.7:1. A novel phantom for the evaluation of PET-AS algorithms was developed. It is provided with both reference contours and activity ground truth, and it covers a wide range of volumes and lesion to background contrasts. The dataset is open to the community of PET-AS developers and utilizers. © 2016 American Association of Physicists in Medicine.

Tumor Heterogeneity in Breast Cancer

PubMed Central

Turashvili, Gulisa; Brogi, Edi

2017-01-01

Breast cancer is a heterogeneous disease and differs greatly among different patients (intertumor heterogeneity) and even within each individual tumor (intratumor heterogeneity). Clinical and morphologic intertumor heterogeneity is reflected by staging systems and histopathologic classification of breast cancer. Heterogeneity in the expression of established prognostic and predictive biomarkers, hormone receptors, and human epidermal growth factor receptor 2 oncoprotein is the basis for targeted treatment. Molecular classifications are indicators of genetic tumor heterogeneity, which is probed with multigene assays and can lead to improved stratification into low- and high-risk groups for personalized therapy. Intratumor heterogeneity occurs at the morphologic, genomic, transcriptomic, and proteomic levels, creating diagnostic and therapeutic challenges. Understanding the molecular and cellular mechanisms of tumor heterogeneity that are relevant to the development of treatment resistance is a major area of research. Despite the improved knowledge of the complex genetic and phenotypic features underpinning tumor heterogeneity, there has been only limited advancement in diagnostic, prognostic, or predictive strategies for breast cancer. The current guidelines for reporting of biomarkers aim to maximize patient eligibility for targeted therapy, but do not take into account intratumor heterogeneity. The molecular classification of breast cancer is not implemented in routine clinical practice. Additional studies and in-depth analysis are required to understand the clinical significance of rapidly accumulating data. This review highlights inter- and intratumor heterogeneity of breast carcinoma with special emphasis on pathologic findings, and provides insights into the clinical significance of molecular and cellular mechanisms of heterogeneity. PMID:29276709

Pattern Analysis of Dynamic Susceptibility Contrast-enhanced MR Imaging Demonstrates Peritumoral Tissue Heterogeneity

PubMed Central

Akbari, Hamed; Macyszyn, Luke; Da, Xiao; Wolf, Ronald L.; Bilello, Michel; Verma, Ragini; O’Rourke, Donald M.

2014-01-01

Purpose To augment the analysis of dynamic susceptibility contrast material–enhanced magnetic resonance (MR) images to uncover unique tissue characteristics that could potentially facilitate treatment planning through a better understanding of the peritumoral region in patients with glioblastoma. Materials and Methods Institutional review board approval was obtained for this study, with waiver of informed consent for retrospective review of medical records. Dynamic susceptibility contrast-enhanced MR imaging data were obtained for 79 patients, and principal component analysis was applied to the perfusion signal intensity. The first six principal components were sufficient to characterize more than 99% of variance in the temporal dynamics of blood perfusion in all regions of interest. The principal components were subsequently used in conjunction with a support vector machine classifier to create a map of heterogeneity within the peritumoral region, and the variance of this map served as the heterogeneity score. Results The calculated principal components allowed near-perfect separability of tissue that was likely highly infiltrated with tumor and tissue that was unlikely infiltrated with tumor. The heterogeneity map created by using the principal components showed a clear relationship between voxels judged by the support vector machine to be highly infiltrated and subsequent recurrence. The results demonstrated a significant correlation (r = 0.46, P < .0001) between the heterogeneity score and patient survival. The hazard ratio was 2.23 (95% confidence interval: 1.4, 3.6; P < .01) between patients with high and low heterogeneity scores on the basis of the median heterogeneity score. Conclusion Analysis of dynamic susceptibility contrast-enhanced MR imaging data by using principal component analysis can help identify imaging variables that can be subsequently used to evaluate the peritumoral region in glioblastoma. These variables are potentially indicative of tumor infiltration and may become useful tools in guiding therapy, as well as individualized prognostication. © RSNA, 2014 PMID:24955928

Habitat size modulates the influence of heterogeneity on species richness patterns in a model zooplankton community.

PubMed

Schuler, Matthew S; Chase, Jonathan M; Knight, Tiffany M

2017-06-01

Habitat heterogeneity is a primary mechanism influencing species richness. Despite the general expectation that increased heterogeneity should increase species richness, there is considerable variation in the observed relationship, including many studies that show negative effects of heterogeneity on species richness. One mechanism that can create such disparate results is the predicted trade-off between habitat area and heterogeneity, sometimes called the area-heterogeneity-trade-off (AHTO) hypothesis. The AHTO hypothesis predicts positive effects of heterogeneity on species richness in large habitats, but negative effects in small habitats. We examined the interplay between habitat size and habitat heterogeneity in experimental mesocosms that mimic freshwater ponds, and measured responses in a species-rich zooplankton community. We used the AHTO hypothesis and related mechanisms to make predictions about how heterogeneity would affect species richness and diversity in large compared to small habitats. We found that heterogeneity had a positive influence on species richness in large, but not small habitats, and that this likely resulted because habitat specialists were able to persist only when habitat size was sufficiently large, consistent with the predictions of the AHTO hypothesis. Our results emphasize the importance of considering context (e.g., habitat size in this case) when investigating the relative importance of ecological drivers of diversity, like heterogeneity. © 2017 by the Ecological Society of America.

The evolution of recombination in a heterogeneous environment.

PubMed Central

Lenormand, T; Otto, S P

2000-01-01

Most models describing the evolution of recombination have focused on the case of a single population, implicitly assuming that all individuals are equally likely to mate and that spatial heterogeneity in selection is absent. In these models, the evolution of recombination is driven by linkage disequilibria generated either by epistatic selection or drift. Models based on epistatic selection show that recombination can be favored if epistasis is negative and weak compared to directional selection and if the recombination modifier locus is tightly linked to the selected loci. In this article, we examine the joint effects of spatial heterogeneity in selection and epistasis on the evolution of recombination. In a model with two patches, each subject to different selection regimes, we consider the cases of mutation-selection and migration-selection balance as well as the spread of beneficial alleles. We find that including spatial heterogeneity extends the range of epistasis over which recombination can be favored. Indeed, recombination can be favored without epistasis, with negative and even with positive epistasis depending on environmental circumstances. The selection pressure acting on recombination-modifier loci is often much stronger with spatial heterogeneity, and even loosely linked modifiers and free linkage may evolve. In each case, predicting whether recombination is favored requires knowledge of both the type of environmental heterogeneity and epistasis, as none of these factors alone is sufficient to predict the outcome. PMID:10978305

Demographically Adjusted Groups for Equating Test Scores. Research Report. ETS RR-14-30

ERIC Educational Resources Information Center

Livingston, Samuel A.

2014-01-01

In this study, I investigated 2 procedures intended to create test-taker groups of equal ability by poststratifying on a composite variable created from demographic information. In one procedure, the stratifying variable was the composite variable that best predicted the test score. In the other procedure, the stratifying variable was the…

Fractions: How to Fair Share

ERIC Educational Resources Information Center

Wilson, P. Holt; Edgington, Cynthia P.; Nguyen, Kenny H.; Pescosolido, Ryan S.; Confrey, Jere

2011-01-01

Children learn from a very early age what it means to get their "fair share." Whether it is candy or birthday cake, many children successfully create equal-size groups or parts of a collection or whole but later struggle to create fair shares of multiple wholes, such as fairly sharing four pies among a family of seven. Recent research suggests…

Forms of Self-Concept in Gifted High School Students Enrolled in Heterogeneous Classes

ERIC Educational Resources Information Center

Villatte, Aude; Hugon, Mandarine; de Leonardis, Myriam

2011-01-01

Prior research has been devoted to understanding how to facilitate the integration of gifted young people (Intelligence Quotient, greater than or equal to 130) into classroom settings. This study investigated a typology of self-concept in gifted French high school students. Eighty-four participants, between the ages of 13 and 18 (mean age, 15.5;…

Microstructure and Mechanical Properties of Ultrafine-Grained Al-6061 Prepared Using Intermittent Ultrasonic-Assisted Equal-Channel Angular Pressing

NASA Astrophysics Data System (ADS)

Lu, Jianxun; Wu, Xiaoyu; Wu, Zhaozhi; Liu, Zhiyuan; Guo, Dengji; Lou, Yan; Ruan, Shuangchen

2017-10-01

Equal-channel angular pressing (ECAP) is an efficient technique to achieve grain refinement in a wide range of materials. However, the extrusion process requires an excessive extrusion force, the microstructure of ECAPed specimens scatters heterogeneously because of considerable fragmentation of the structure and strain heterogeneity, and the resultant ultrafine grains exhibit poor thermal stability. The intermittent ultrasonic-assisted ECAP (IU-ECAP) approach was proposed to address these issues. In this work, ECAP and IU-ECAP were applied to produce ultrafine-grained Al-6061 alloys, and the differences in their mechanical properties, microstructural characteristics, and thermal stability were investigated. Mechanical testing demonstrated that the necessary extrusion force for IU-ECAP was significantly reduced; even more, the microhardness and ultimate tensile strength were strengthened. In addition, the IU-ECAPed Al alloy exhibited a smaller grain size with a more homogeneous microstructure. X-ray diffraction analysis indicated that the intensities of the textures were weakened using IU-ECAP, and a more homogeneous microstructure and larger dislocation densities were obtained. Investigation of the thermal stability revealed that the ultrafine-grained materials produced using IU-ECAP recrystallized at higher temperature or after longer time; the materials thus exhibited improved thermal stability.

Enhanced Handover Decision Algorithm in Heterogeneous Wireless Network

PubMed Central

Abdullah, Radhwan Mohamed; Zukarnain, Zuriati Ahmad

2017-01-01

Transferring a huge amount of data between different network locations over the network links depends on the network’s traffic capacity and data rate. Traditionally, a mobile device may be moved to achieve the operations of vertical handover, considering only one criterion, that is the Received Signal Strength (RSS). The use of a single criterion may cause service interruption, an unbalanced network load and an inefficient vertical handover. In this paper, we propose an enhanced vertical handover decision algorithm based on multiple criteria in the heterogeneous wireless network. The algorithm consists of three technology interfaces: Long-Term Evolution (LTE), Worldwide interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). It also employs three types of vertical handover decision algorithms: equal priority, mobile priority and network priority. The simulation results illustrate that the three types of decision algorithms outperform the traditional network decision algorithm in terms of handover number probability and the handover failure probability. In addition, it is noticed that the network priority handover decision algorithm produces better results compared to the equal priority and the mobile priority handover decision algorithm. Finally, the simulation results are validated by the analytical model. PMID:28708067

Quantification and Control of Wall Effects in Porous Media Experiments

NASA Astrophysics Data System (ADS)

Roth, E. J.; Mays, D. C.; Neupauer, R.; Crimaldi, J. P.

2017-12-01

Fluid flow dynamics in porous media are dominated by media heterogeneity. This heterogeneity can create preferential pathways in which local seepage velocities dwarf system seepage velocities, further complicating an already incomplete understanding of dispersive processes. In physical models of porous media flows, apparatus walls introduce preferential flow paths (i.e., wall effects) that may overwhelm other naturally occurring preferential pathways within the apparatus, leading to deceptive results. We used planar laser-induced fluorescence (PLIF) in conjunction with refractive index matched (RIM) porous media and pore fluid to observe fluid dynamics in the porous media, with particular attention to the region near the apparatus walls in a 17 cm x 8 cm x 7 cm uniform flow cell. Hexagonal close packed spheres were used to create an isotropic, homogenous porous media field in the interior of the apparatus. Visualization of the movement of a fluorescent dye revealed the influence of the wall in creating higher permeability preferential flow paths in an otherwise homogenous media packing. These preferential flow paths extended approximately one half of one sphere diameter from the wall for homogenously packed regions, with a quickly diminishing effect on flow dynamics for homogenous media adjacent to the preferential pathway, but with major influence on flow dynamics for adjoining heterogeneous regions. Multiple approaches to mitigate wall effects were investigated, and a modified wall was created such that the fluid dynamics near the wall mimics the fluid dynamics within the homogenous porous media. This research supports the design of a two-dimensional experimental apparatus that will simulate engineered pumping schemes for use in contaminant remediation. However, this research could benefit the design of fixed bed reactors or other engineering challenges in which vessel walls contribute to unwanted preferential flow.

Homelessness prevention in New York City: On average, it works

PubMed Central

Goodman, Sarena; Messeri, Peter; O'Flaherty, Brendan

2016-01-01

This study evaluates the community impact of the first four years of Homebase, a homelessness prevention program in New York City. Family shelter entries decreased on average in the neighborhoods in which Homebase was operating. Homebase effects appear to be heterogeneous, and so different kinds of averages imply different-sized effects. The (geometric) average decrease in shelter entries was about 5% when census tracts are weighted equally, and 11% when community districts (which are much larger) are weighted equally. This study also examines the effect of foreclosures. Foreclosures are associated with more shelter entries in neighborhoods that usually do not send large numbers of families to the shelter system. PMID:26941543

Concentrative nitrogen allocation to sun-lit branches and the effects on whole-plant growth under heterogeneous light environments.

PubMed

Sugiura, D; Tateno, M

2013-08-01

We investigated the nitrogen and carbohydrate allocation patterns of trees under heterogeneous light environments using saplings of the devil maple tree (Acer diabolicum) with Y-shaped branches. Different branch groups were created: all branches of a sapling exposed to full light (L-branches), all branches exposed to full shade (S-branches), and half of the branches of a sapling exposed to light (HL-branches) and the other half exposed to shade (HS-branches). Throughout the growth period, nitrogen was preferentially allocated to HL-branches, whereas nitrogen allocation to HS-branches was suppressed compared to L- and S-branches. HL-branches with the highest leaf nitrogen content (N(area)) also had the highest rates of growth, and HS-branches with the lowest N(area) had the lowest observed growth rates. In addition, net nitrogen assimilation, estimated using a photosynthesis model, was strongly correlated with branch growth and whole-plant growth. In contrast, patterns of photosynthate allocation to branches and roots were not affected by the light conditions of the other branch. These observations suggest that tree canopies develop as a result of resource allocation patterns, where the growth of sun-lit branches is favoured over shaded branches, which leads to enhanced whole-plant growth in heterogeneous light environments. Our results indicate that whole-plant growth is enhanced by the resource allocation patterns created for saplings in heterogeneous light environments.

Gendered power in cultural contexts: Part III. Couple relationships in Iran.

PubMed

Moghadam, Seddigheh; Knudson-Martin, Carmen; Mahoney, Anne Rankin

2009-03-01

Sometimes therapists assume that gender equality is not relevant when working with couples from traditional cultures. This study of couples in Iran suggests more complexity. The authors identify a variety of views and practices regarding equality between men and women in relationships. Some aspired to traditional roles; others attempted to create mutually supportive relationships. Yet others were somewhere in-between. This study helps identify important dimensions that may be overlooked when we define couple equality only by American standards or understand it only through a Western lens. The study provides insight into the dilemmas couples face when ideals of equality intersect with societal structures that maintain gendered power and offers suggestions for addressing gender when working with couples with traditional cultural backgrounds.

Growing Down -- Increasing Diversity as the Army Gets Smaller

DTIC Science & Technology

2012-03-19

purpose. The Fahy Committee was created to carry out President Truman’s equal treatment and opportunity policy in both the federal government and the...military. The Gesell Committee, on the other hand, was more concerned with developing a new equal treatment strategy than assessing the existing...developing this focal group will also establish organizational norms which will benefit women and other minority populations. Further, following the

The key particle and quark energy equality E W + E Z = E top

NASA Astrophysics Data System (ADS)

Mac Gregor, Malcolm H.

2017-11-01

Precision Tevatron and Linear Hadron Collider measurements at Fermilab and CERN have revealed the numerically accurate mass equality W + Z = t. This equality between two gauge bosons ( gb) and the top quark t is only valid if reinterpreted as an energy equality, where E = mc 2, since energy is a shared property of particles and quarks. The experimental data indicate that the LHC particle excitation energy is quantized in the form of gauge boson energy packets E gb , which are created by factor-of-137 proton-quark energy increases denoted as α- boosts, where α 1/137 is the fine structure constant. These α-boosts occur during the rare head-on quark-quark collisions in the proton beams. The α-boost energy quantization mechanism also occurs in low-energy electron-positron boson and fermion particle production channels, where it generates E b and E f energy packets. These α-boost energy channels link together coherently, as demonstrated by the accurate top quark energy equation E top = (18/α2) E electron. Particle production energy equations are derived which combine to create an overall energy pattern that accurately reproduces the energies of the ( u, d), s, c, b, t fermion constituent quarks, the µ and τ leptons, and the proton.

Information mining over heterogeneous and high-dimensional time-series data in clinical trials databases.

PubMed

Altiparmak, Fatih; Ferhatosmanoglu, Hakan; Erdal, Selnur; Trost, Donald C

2006-04-01

An effective analysis of clinical trials data involves analyzing different types of data such as heterogeneous and high dimensional time series data. The current time series analysis methods generally assume that the series at hand have sufficient length to apply statistical techniques to them. Other ideal case assumptions are that data are collected in equal length intervals, and while comparing time series, the lengths are usually expected to be equal to each other. However, these assumptions are not valid for many real data sets, especially for the clinical trials data sets. An addition, the data sources are different from each other, the data are heterogeneous, and the sensitivity of the experiments varies by the source. Approaches for mining time series data need to be revisited, keeping the wide range of requirements in mind. In this paper, we propose a novel approach for information mining that involves two major steps: applying a data mining algorithm over homogeneous subsets of data, and identifying common or distinct patterns over the information gathered in the first step. Our approach is implemented specifically for heterogeneous and high dimensional time series clinical trials data. Using this framework, we propose a new way of utilizing frequent itemset mining, as well as clustering and declustering techniques with novel distance metrics for measuring similarity between time series data. By clustering the data, we find groups of analytes (substances in blood) that are most strongly correlated. Most of these relationships already known are verified by the clinical panels, and, in addition, we identify novel groups that need further biomedical analysis. A slight modification to our algorithm results an effective declustering of high dimensional time series data, which is then used for "feature selection." Using industry-sponsored clinical trials data sets, we are able to identify a small set of analytes that effectively models the state of normal health.

What Does It Mean to Be a Girl? Teachers' Representations of Gender in Supplementary Reading Materials for South African Schools

ERIC Educational Resources Information Center

Dentith, Audrey M.; Sailors, Misty; Sethusha, Mantsose

2016-01-01

Education reform, including methods to create greater gender equality, is an ongoing process in post-Apartheid South Africa. Using an African feminism theoretical framework and a critical content analysis approach, we examined the representation of female characters in a subset of supplementary reading titles created under an international…

Poverty, Equity and Access to Education in Bangladesh. CREATE Pathways to Access. Research Monograph No. 51

ERIC Educational Resources Information Center

Hossain, Altaf; Zeitlyn, Benjamin

2010-01-01

Bangladesh has made great improvements in the scale and quality of access to education in recent years and gender equality has almost been achieved in primary education (World Bank, 2008). Evidence from CREATE's nationwide community and school survey (ComSS) confirms results from other research (such as Al-Samarrai, 2009) which suggests that…

Zebrafish as a model to assess cancer heterogeneity, progression and relapse

PubMed Central

Blackburn, Jessica S.; Langenau, David M.

2014-01-01

Clonal evolution is the process by which genetic and epigenetic diversity is created within malignant tumor cells. This process culminates in a heterogeneous tumor, consisting of multiple subpopulations of cancer cells that often do not contain the same underlying mutations. Continuous selective pressure permits outgrowth of clones that harbor lesions that are capable of enhancing disease progression, including those that contribute to therapy resistance, metastasis and relapse. Clonal evolution and the resulting intratumoral heterogeneity pose a substantial challenge to biomarker identification, personalized cancer therapies and the discovery of underlying driver mutations in cancer. The purpose of this Review is to highlight the unique strengths of zebrafish cancer models in assessing the roles that intratumoral heterogeneity and clonal evolution play in cancer, including transgenesis, imaging technologies, high-throughput cell transplantation approaches and in vivo single-cell functional assays. PMID:24973745

Transient electroosmotic flow induced by AC electric field in micro-channel with patchwise surface heterogeneities.

PubMed

Luo, Win-Jet

2006-03-15

This paper investigates two-dimensional, time-dependent electroosmotic flow driven by an AC electric field via patchwise surface heterogeneities distributed along the micro-channel walls. The time-dependent flow fields through the micro-channel are simulated for various patchwise heterogeneous surface patterns using the backwards-Euler time stepping numerical method. Different heterogeneous surface patterns are found to create significantly different electrokinetic transport phenomena. The transient behavior characteristics of the generated electroosmotic flow are then discussed in terms of the influence of the patchwise surface heterogeneities, the direction of the applied AC electric field, and the velocity of the bulk flow. It is shown that the presence of oppositely charged surface heterogeneities on the micro-channel walls results in the formation of localized flow circulations within the bulk flow. These circulation regions grow and decay periodically in phase with the applied periodic AC electric field intensity. The location and rotational direction of the induced circulations are determined by the directions of the bulk flow velocity and the applied electric field.

High effective heterogeneous plasma vortex reactor for production of heat energy and hydrogen

NASA Astrophysics Data System (ADS)

Belov, N. K.; Zavershinskii, I. P.; Klimov, A. I.; Molevich, N. E.; Porfiriev, D. P.; Tolkunov, B. N.

2018-03-01

This work is a continuation of our previous studies [1-10] of physical parameters and properties of a long-lived heterogeneous plasmoid (plasma formation with erosive nanoclusters) created by combined discharge in a high-speed swirl flow. Here interaction of metal nanoclusters with hydrogen atoms is studied in a plasma vortex reactor (PVR) with argon-water steam mixture. Metal nanoclusters were created by nickel cathode’s erosion at combined discharge on. Dissociated hydrogen atoms and ions were obtained in water steam by electric discharge. These hydrogen atoms and ions interacted with metal nanoclusters, which resulted in the creation of a stable plasmoid in a swirl gas flow. This plasmoid has been found to create intensive soft X-ray radiation. Plasma parameters of this plasmoid were measured by optical spectroscopy method. It has been obtained that there is a high non-equilibrium plasmoid: Te > TV >> TR. The measured coefficient of energy performance of this plasmoid is about COP = 2÷10. This extra power release in plasmoid is supposed to be connected with internal excited electrons. The obtained experimental results have proved our suggestion.

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

Iwai, P; Lins, L Nadler

Purpose: There is a lack of studies with significant cohort data about patients using pacemaker (PM), implanted cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) device undergoing radiotherapy. There is no literature comparing the cumulative doses delivered to those cardiac implanted electronic devices (CIED) calculated by different algorithms neither studies comparing doses with heterogeneity correction or not. The aim of this study was to evaluate the influence of the algorithms Pencil Beam Convolution (PBC), Analytical Anisotropic Algorithm (AAA) and Acuros XB (AXB) as well as heterogeneity correction on risk categorization of patients. Methods: A retrospective analysis of 19 3DCRT ormore » IMRT plans of 17 patients was conducted, calculating the dose delivered to CIED using three different calculation algorithms. Doses were evaluated with and without heterogeneity correction for comparison. Risk categorization of the patients was based on their CIED dependency and cumulative dose in the devices. Results: Total estimated doses at CIED calculated by AAA or AXB were higher than those calculated by PBC in 56% of the cases. In average, the doses at CIED calculated by AAA and AXB were higher than those calculated by PBC (29% and 4% higher, respectively). The maximum difference of doses calculated by each algorithm was about 1 Gy, either using heterogeneity correction or not. Values of maximum dose calculated with heterogeneity correction showed that dose at CIED was at least equal or higher in 84% of the cases with PBC, 77% with AAA and 67% with AXB than dose obtained with no heterogeneity correction. Conclusion: The dose calculation algorithm and heterogeneity correction did not change the risk categorization. Since higher estimated doses delivered to CIED do not compromise treatment precautions to be taken, it’s recommend that the most sophisticated algorithm available should be used to predict dose at the CIED using heterogeneity correction.« less

Biological challenges to effective vaccines in the developing world

PubMed Central

Grassly, Nicholas C.; Kang, Gagandeep; Kampmann, Beate

2015-01-01

The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy. PMID:25964451

A novel algorithm for fully automated mapping of geospatial ontologies

NASA Astrophysics Data System (ADS)

Chaabane, Sana; Jaziri, Wassim

2018-01-01

Geospatial information is collected from different sources thus making spatial ontologies, built for the same geographic domain, heterogeneous; therefore, different and heterogeneous conceptualizations may coexist. Ontology integrating helps creating a common repository of the geospatial ontology and allows removing the heterogeneities between the existing ontologies. Ontology mapping is a process used in ontologies integrating and consists in finding correspondences between the source ontologies. This paper deals with the "mapping" process of geospatial ontologies which consist in applying an automated algorithm in finding the correspondences between concepts referring to the definitions of matching relationships. The proposed algorithm called "geographic ontologies mapping algorithm" defines three types of mapping: semantic, topological and spatial.

Black Youth in Cuba

ERIC Educational Resources Information Center

Horne, Gerald C.

1975-01-01

Cuban social system has eliminated discrimination, racism, sexism and unemployment and created equal opportunity for all. Cuba is upheld as model for all forward looking U.S. citizens to study. (Author/AM)

Flexible method for monitoring fuel cell voltage

DOEpatents

Mowery, Kenneth D.; Ripley, Eugene V.

2002-01-01

A method for equalizing the measured voltage of each cluster in a fuel cell stack wherein at least one of the clusters has a different number of cells than the identical number of cells in the remaining clusters by creating a pseudo voltage for the different cell numbered cluster. The average cell voltage of the all of the cells in the fuel cell stack is calculated and multiplied by a constant equal to the difference in the number of cells in the identical cell clusters and the number of cells in the different numbered cell cluster. The resultant product is added to the actual voltage measured across the different numbered cell cluster to create a pseudo voltage which is equivalent in cell number to the number of cells in the other identical numbered cell clusters.

A predator equalizes rate of capture of a schooling prey in a patchy environment.

PubMed

Vijayan, Sundararaj; Kotler, Burt P; Abramsky, Zvika

2017-05-01

Prey individuals are often distributed heterogeneously in the environment, and their abundances and relative availabilities vary among patches. A foraging predator should maximize energetic gains by selectively choosing patches with higher prey density. However, catching behaviorally responsive and group-forming prey in patchy environments can be a challenge for predators. First, they have to identify the profitable patches, and second, they must manage the prey's sophisticated anti-predator behavior. Thus, the forager and its prey have to continuously adjust their behavior to that of their opponent. Given these conditions, the foraging predator's behavior should be dynamic with time in terms of foraging effort and prey capture rates across different patches. Theoretically, the allocation of its time among patches of behaviorally responsive prey should be such that it equalizes its prey capture rates across patches through time. We tested this prediction in a model system containing a predator (little egret) and group-forming prey (common gold fish) in two sets of experiments in which (1) patches (pools) contained equal numbers of prey, or in which (2) patches contained unequal densities of prey. The egret equalized the prey capture rate through time in both equal and different density experiments. Copyright © 2017 Elsevier B.V. All rights reserved.

Melting Heat in Radiative Flow of Carbon Nanotubes with Homogeneous-Heterogeneous Reactions

NASA Astrophysics Data System (ADS)

Hayat, Tasawar; Muhammad, Khursheed; Muhammad, Taseer; Alsaedi, Ahmed

2018-04-01

The present article provides mathematical modeling for melting heat and thermal radiation in stagnation-point flow of carbon nanotubes towards a nonlinear stretchable surface of variable thickness. The process of homogeneous-heterogeneous reactions is considered. Diffusion coefficients are considered equal for both reactant and autocatalyst. Water and gasoline oil are taken as base fluids. The conversion of partial differential system to ordinary differential system is done by suitable transformations. Optimal homotopy technique is employed for the solutions development of velocity, temperature, concentration, skin friction and local Nusselt number. Graphical results for various values of pertinent parameters are displayed and discussed. Our results indicate that the skin friction coefficient and local Nusselt number are enhanced for larger values of nanoparticles volume fraction.

Health Implications of the Supreme Court's Obergefell vs. Hodges Marriage Equality Decision

PubMed Central

2015-01-01

Abstract The United States Supreme Court's Obergefell vs. Hodges groundbreaking marriage equality decision also created new terrain for lesbian, gay, bisexual, and transgender (LGBT) persons regarding health, healthcare, and health benefits. This article addresses the health implications of this decision by examining its impact on minority stress and stigmatization and health-related benefits. It also includes a discussion of several impending issues affecting LGBT health that remain after Obergefell. PMID:26788668

Health Implications of the Supreme Court's Obergefell vs. Hodges Marriage Equality Decision.

PubMed

Perone, Angela K

2015-09-01

The United States Supreme Court's Obergefell vs. Hodges groundbreaking marriage equality decision also created new terrain for lesbian, gay, bisexual, and transgender (LGBT) persons regarding health, healthcare, and health benefits. This article addresses the health implications of this decision by examining its impact on minority stress and stigmatization and health-related benefits. It also includes a discussion of several impending issues affecting LGBT health that remain after Obergefell.

SU-F-T-604: Dosimetric Evaluation of Intracranial Stereotactic Radiotherapy Plans On a LINAC

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

Sheth, N; Tabibian, A; Rose, J

2016-06-15

Purpose: To evaluate the dosimetry of cranial stereotactic radiotherapy (SRT) plans of varying techniques on linac that meets appropriate TG-142 tolerances using 1 cm leaf width multileaf collimator (MLC). Methods: Seventeen spherical targets were generated in the center of a head phantom with diameters ranging 8 mm to 40 mm. SRT plans used 100° non-coplanar arcs and 5 couch angles with 35° spacing. The field size was target plus 1 mm margin. Four plans were created for each target: symmetrical jaws blocking for 5 arcs with 0° collimator (J1C), symmetrical jaws blocking with 5 clockwise arcs with 0° collimator andmore » 5 counter-clockwise arcs with 45° collimator (J2C), MLC blocking for 5 dynamic conformal arcs with 0° collimator (M1C), and MLC blocking for 5 clockwise dynamic conformal arcs with 0° collimators and 5 counter-clockwise dynamic conformal arcs with 45° collimator (M2C).Conformity was evaluated using a ratio of Rx to target volume (PITV). Heterogeneity was determined using a ratio of maximum dose to Rx dose. Falloff was scored using CGIg: difference of effective radii of spheres equal to half and full Rx volumes. Results: All plans met RTOG SRS criteria for conformity and heterogeneity. The mean PITV was 1.52±0.07, 1.49±0.08, 1.39±0.05, and 1.37±0.04 for J1C, J2C, M1C, and M2C plans respectively. The mean CGIg was 75.35±15.79, 74.19±16.66, 77.14±15.12, and 76.28±15.78 for J1C, J2C, M1C, and M2C plans respectively. The mean MDPD was 1.25±0.00 for all techniques. Conclusion: Clinically acceptable SRT plans for spherical targets were created on a linac with 1 cm MLC. Adding two collimator angles and MLC to arcs each improved conformity. The MLC improved the dose falloff while two collimator angles degraded it. This technique can expand the availability of SRT to patients especially to those who cannot travel to a facility with a dedicated stereotactic radiosurgery machine.« less

Experimental protocol for manipulating plant-induced soil heterogeneity.

PubMed

Brandt, Angela J; del Pino, Gaston A; Burns, Jean H

2014-03-13

Coexistence theory has often treated environmental heterogeneity as being independent of the community composition; however biotic feedbacks such as plant-soil feedbacks (PSF) have large effects on plant performance, and create environmental heterogeneity that depends on the community composition. Understanding the importance of PSF for plant community assembly necessitates understanding of the role of heterogeneity in PSF, in addition to mean PSF effects. Here, we describe a protocol for manipulating plant-induced soil heterogeneity. Two example experiments are presented: (1) a field experiment with a 6-patch grid of soils to measure plant population responses and (2) a greenhouse experiment with 2-patch soils to measure individual plant responses. Soils can be collected from the zone of root influence (soils from the rhizosphere and directly adjacent to the rhizosphere) of plants in the field from conspecific and heterospecific plant species. Replicate collections are used to avoid pseudoreplicating soil samples. These soils are then placed into separate patches for heterogeneous treatments or mixed for a homogenized treatment. Care should be taken to ensure that heterogeneous and homogenized treatments experience the same degree of soil disturbance. Plants can then be placed in these soil treatments to determine the effect of plant-induced soil heterogeneity on plant performance. We demonstrate that plant-induced heterogeneity results in different outcomes than predicted by traditional coexistence models, perhaps because of the dynamic nature of these feedbacks. Theory that incorporates environmental heterogeneity influenced by the assembling community and additional empirical work is needed to determine when heterogeneity intrinsic to the assembling community will result in different assembly outcomes compared with heterogeneity extrinsic to the community composition.

Multidimensional Modeling of Atmospheric Effects and Surface Heterogeneities on Remote Sensing

NASA Technical Reports Server (NTRS)

Gerstl, S. A. W.; Simmer, C.; Zardecki, A. (Principal Investigator)

1985-01-01

The overall goal of this project is to establish a modeling capability that allows a quantitative determination of atmospheric effects on remote sensing including the effects of surface heterogeneities. This includes an improved understanding of aerosol and haze effects in connection with structural, angular, and spatial surface heterogeneities. One important objective of the research is the possible identification of intrinsic surface or canopy characteristics that might be invariant to atmospheric perturbations so that they could be used for scene identification. Conversely, an equally important objective is to find a correction algorithm for atmospheric effects in satellite-sensed surface reflectances. The technical approach is centered around a systematic model and code development effort based on existing, highly advanced computer codes that were originally developed for nuclear radiation shielding applications. Computational techniques for the numerical solution of the radiative transfer equation are adapted on the basis of the discrete-ordinates finite-element method which proved highly successful for one and two-dimensional radiative transfer problems with fully resolved angular representation of the radiation field.

A numerical homogenization method for heterogeneous, anisotropic elastic media based on multiscale theory

DOE PAGES

Gao, Kai; Chung, Eric T.; Gibson, Richard L.; ...

2015-06-05

The development of reliable methods for upscaling fine scale models of elastic media has long been an important topic for rock physics and applied seismology. Several effective medium theories have been developed to provide elastic parameters for materials such as finely layered media or randomly oriented or aligned fractures. In such cases, the analytic solutions for upscaled properties can be used for accurate prediction of wave propagation. However, such theories cannot be applied directly to homogenize elastic media with more complex, arbitrary spatial heterogeneity. We therefore propose a numerical homogenization algorithm based on multiscale finite element methods for simulating elasticmore » wave propagation in heterogeneous, anisotropic elastic media. Specifically, our method used multiscale basis functions obtained from a local linear elasticity problem with appropriately defined boundary conditions. Homogenized, effective medium parameters were then computed using these basis functions, and the approach applied a numerical discretization that is similar to the rotated staggered-grid finite difference scheme. Comparisons of the results from our method and from conventional, analytical approaches for finely layered media showed that the homogenization reliably estimated elastic parameters for this simple geometry. Additional tests examined anisotropic models with arbitrary spatial heterogeneity where the average size of the heterogeneities ranged from several centimeters to several meters, and the ratio between the dominant wavelength and the average size of the arbitrary heterogeneities ranged from 10 to 100. Comparisons to finite-difference simulations proved that the numerical homogenization was equally accurate for these complex cases.« less

Heterogeneity, Mixing, and the Spatial Scales of Mosquito-Borne Pathogen Transmission

PubMed Central

Perkins, T. Alex; Scott, Thomas W.; Le Menach, Arnaud; Smith, David L.

2013-01-01

The Ross-Macdonald model has dominated theory for mosquito-borne pathogen transmission dynamics and control for over a century. The model, like many other basic population models, makes the mathematically convenient assumption that populations are well mixed; i.e., that each mosquito is equally likely to bite any vertebrate host. This assumption raises questions about the validity and utility of current theory because it is in conflict with preponderant empirical evidence that transmission is heterogeneous. Here, we propose a new dynamic framework that is realistic enough to describe biological causes of heterogeneous transmission of mosquito-borne pathogens of humans, yet tractable enough to provide a basis for developing and improving general theory. The framework is based on the ecological context of mosquito blood meals and the fine-scale movements of individual mosquitoes and human hosts that give rise to heterogeneous transmission. Using this framework, we describe pathogen dispersion in terms of individual-level analogues of two classical quantities: vectorial capacity and the basic reproductive number, . Importantly, this framework explicitly accounts for three key components of overall heterogeneity in transmission: heterogeneous exposure, poor mixing, and finite host numbers. Using these tools, we propose two ways of characterizing the spatial scales of transmission—pathogen dispersion kernels and the evenness of mixing across scales of aggregation—and demonstrate the consequences of a model's choice of spatial scale for epidemic dynamics and for estimation of , both by a priori model formulas and by inference of the force of infection from time-series data. PMID:24348223

The influence of microtopography on soil nutrients in created mitigation wetlands

USGS Publications Warehouse

Moser, K.F.; Ahn, C.; Noe, G.B.

2009-01-01

This study explores the relationship between microtopography and soil nutrients (and trace elements), comparing results for created and reference wetlands in Virginia, and examining the effects of disking during wetland creation. Replicate multiscale tangentially conjoined circular transects were used to quantify microtopography both in terms of elevation and by two microtopographic indices. Corresponding soil samples were analyzed for moisture content, total C and N, KCl-extractable NH4-N and NO3-N, and Mehlich-3 extractable P, Ca, Mg, K, Al, Fe, and Mn. Means and variances of soil nutrient/element concentrations were compared between created and natural wetlands and between disked and nondisked created wetlands. Natural sites had higher and more variable soil moisture, higher extractable P and Fe, lower Mn than created wetlands, and comparatively high variability in nutrient concentrations. Disked sites had higher soil moisture, NH4-N, Fe, and Mn than did nondisked sites. Consistently low variances (Levene test for inequality) suggested that nondisked sites had minimal nutrient heterogeneity. Across sites, low P availability was inferred by the molar ratio (Mehlich-3 [P/(Al + Fe)] < 0.06); strong intercorrelations among total C, total N, and extractable Fe, Al, and P suggested that humic-metal-P complexes may be important for P retention and availability. Correlations between nutrient/element concentrations and microtopographic indices suggested increased Mn and decreased K and Al availability with increased surface roughness. Disking appears to enhance water and nutrient retention, as well as nutrient heterogeneity otherwise absent from created wetlands, thus potentially promoting ecosystem development. ?? 2008 Society for Ecological Restoration International.

Differential change in integrative psychotherapy: a re-analysis of a change-factor based RCT in a naturalistic setting.

PubMed

Holtforth, Martin Grosse; Wilm, Katharina; Beyermann, Stefanie; Rhode, Annemarie; Trost, Stephanie; Steyer, Rolf

2011-11-01

General Psychotherapy (GPT; Grawe, 1997) is a research-informed psychotherapy that combines cognitive-behavioral and process-experiential techniques and that assumes motivational clarification and problem mastery as central mechanisms of change. To isolate the effect of motivational clarification, GPT was compared to a treatment that proscribed motivational clarification (General Psychotherapy Minus Clarification, GPT-C) in a randomized-controlled trial with 67 diagnostically heterogeneous outpatients. Previous analyses demonstrated equal outcomes and some superiority for highly avoidant patients in GPT. Re-analyses using causal-analytic methods confirmed equal changes, but also showed superior effects for GPT in highly symptomatic patients. Results are discussed regarding theory, methodological limitations, and implications for research and practice.

Dermal Fibroblasts from Different Layers of Pig Skin Exhibit Different Profibrotic and Morphological Characteristics.

PubMed

Zuo, Yanhai; Yu, Xiaoping; Lu, Shuliang

2016-11-01

In vitro studies of human dermal fibroblast (DF) heterogeneity have long been reported, yet in vivo studies and related research on animals are rare. The objectives of the study were to determine whether the DFs of pigs exhibit heterogeneity and to identify an animal model for the in vivo study of DF heterogeneity. The skin of three female red Duroc pigs (FRDPs) was separated into six layers, and the second and fifth layers (i.e., the superficial and deep dermis) were used in the establishment of wound models and cell cultures. To create the wound models, 54 tongue-shaped flaps were created on one side of the dorsum, and the underlying dermis was then fully replaced with the superficial or deep dermis (the superficial and deep groups, respectively). Skin samples were harvested at postoperative weeks 1, 2, and 3 for measurements of the normal and wounded skin thicknesses. Cells cultured from the superficial and deep dermis (i.e., superficial and deep DFs) were subjected to quantitative estimation of collagen and electron microscopy. The wounded skin thickness in the deep group was significantly greater than that in the superficial group. In contrast with the long deep DFs, the superficial DFs were short and exhibited microvilli-like cell surface projections. Compared with the superficial DFs, the deep DFs exhibited a greater density of rough endoplasmic reticulum and produced significantly more collagen. Similar to humans, FRDPs exhibit DF heterogeneity and should thus be a good animal model for in vivo studies of DF heterogeneity. Anat Rec, 299:1585-1599, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Shrinking cities examined from a shrinking scale – the impact ...

EPA Pesticide Factsheets

Urban populations continue to increase globally and cities have become the dominant human habitat. However, the growth of cities is not universal. Shrinking cities face decreased income, reduced property values, and decreased tax revenue. Fewer people per unit area creates inefficiencies and higher costs for infrastructure maintenance and the provision of public amenities. However, population losses and economic distress are not equal in all neighborhoods, and in fact are quite heterogeneously distributed across the landscape. Broader statements about the trajectory of a shrinking city may mask underlying differences in economic, cultural, and environmental impacts as well as the ability of some neighborhoods to be resilient and adaptive to economic changes as well as climate change and other environmental stressors. This paper examines the recent impact of population loss in neighborhoods in the Río Piedras watershed in San Juan, Puerto Rico, on the provision of ecosystem services, material and energy flows, and ecological impacts, using public data and data collected previously in two household surveys. Using scenarios, we estimate future population changes and their potential positive and negative impacts on the environment and human well-being in these neighborhoods. This paper expands on prior research on shrinking cities by examining the impacts of population loss on urban social-ecological systems at the household and neighborhood scales. The purpose

Mammalian Models for the Study of H7 Virus Pathogenesis and Transmission

PubMed Central

Belser, Jessica A.; Tumpey, Terrence M.

2018-01-01

Mammalian models, most notably the mouse and ferret, have been instrumental in the assessment of avian influenza virus pathogenicity and transmissibility, and have been used widely to characterize the molecular determinants that confer H5N1 virulence in mammals. However, while H7 influenza viruses have typically been associated with conjunctivitis and/or mild respiratory disease in humans, severe disease and death is also possible, as underscored by the recent emergence of H7N9 viruses in China. Despite the public health need to understand the pandemic potential of this virus subtype, H7 virus pathogenesis and transmission has not been as extensively studied. In this review, we discuss the heterogeneity of H7 subtype viruses isolated from humans, and the characterization of mammalian models to study the virulence of H7 subtype viruses associated with human infection, including viruses of both high and low pathogenicity and following multiple inoculation routes. The use of the ferret transmission model to assess the influence of receptor binding preference among contemporary H7 influenza viruses is described. These models have enabled the study of preventative and therapeutic agents, including vaccines and antivirals, to reduce disease burden, and have permitted a greater appreciation that not all highly pathogenic influenza viruses are created equal. PMID:24996862

Integrated conservation and development: evaluating a community-based marine protected area project for equality of socioeconomic impacts.

PubMed

Gurney, Georgina G; Pressey, Robert L; Cinner, Joshua E; Pollnac, Richard; Campbell, Stuart J

2015-11-05

Despite the prevalence of protected areas, evidence of their impacts on people is weak and remains hotly contested in conservation policy. A key question in this debate is whether socioeconomic impacts vary according to social subgroup. Given that social inequity can create conflict and impede poverty reduction, understanding how protected areas differentially affect people is critical to designing them to achieve social and biological goals. Understanding heterogeneous responses to protected areas can improve targeting of management activities and help elucidate the pathways through which impacts of protected areas occur. Here, we assessed whether the socioeconomic impacts of marine protected areas (MPAs)-designed to achieve goals for both conservation and poverty alleviation-differed according to age, gender or religion in associated villages in North Sulawesi, Indonesia. Using data from pre-, mid- and post-implementation of the MPAs for control and project villages, we found little empirical evidence that impacts on five key socioeconomic indicators related to poverty differed according to social subgroup. We found suggestive empirical evidence that the effect of the MPAs on environmental knowledge differed by age and religion; over the medium and long terms, younger people and Muslims showed greater improvements compared with older people and Christians, respectively. © 2015 The Author(s).

Sexual scripts among young heterosexually active men and women: continuity and change.

PubMed

Masters, N Tatiana; Casey, Erin; Wells, Elizabeth A; Morrison, Diane M

2013-01-01

Whereas gendered sexual scripts are hegemonic at the cultural level, research suggests they may be less so at dyadic and individual levels. Understanding "disjunctures" between sexual scripts at different levels holds promise for illuminating mechanisms through which sexual scripts can change. Through interviews with 44 heterosexually active men and women aged 18 to 25, the ways young people grappled with culture-level scripts for sexuality and relationships were delineated. Findings suggest that, although most participants' culture-level gender scripts for behavior in sexual relationships were congruent with descriptions of traditional masculine and feminine sexuality, there was heterogeneity in how or whether these scripts were incorporated into individual relationships. Specifically, three styles of working with sexual scripts were found: conforming, in which personal gender scripts for sexual behavior overlapped with traditional scripts; exception-finding, in which interviewees accepted culture-level gender scripts as a reality, but created exceptions to gender rules for themselves; and transforming, in which participants either attempted to remake culture-level gender scripts or interpreted their own nontraditional styles as equally normative. Changing sexual scripts can potentially contribute to decreased gender inequity in the sexual realm and to increased opportunities for sexual satisfaction, safety, and well-being, particularly for women, but for men as well.

Integrated conservation and development: evaluating a community-based marine protected area project for equality of socioeconomic impacts

PubMed Central

Gurney, Georgina G.; Pressey, Robert L.; Cinner, Joshua E.; Pollnac, Richard; Campbell, Stuart J.

2015-01-01

Despite the prevalence of protected areas, evidence of their impacts on people is weak and remains hotly contested in conservation policy. A key question in this debate is whether socioeconomic impacts vary according to social subgroup. Given that social inequity can create conflict and impede poverty reduction, understanding how protected areas differentially affect people is critical to designing them to achieve social and biological goals. Understanding heterogeneous responses to protected areas can improve targeting of management activities and help elucidate the pathways through which impacts of protected areas occur. Here, we assessed whether the socioeconomic impacts of marine protected areas (MPAs)—designed to achieve goals for both conservation and poverty alleviation—differed according to age, gender or religion in associated villages in North Sulawesi, Indonesia. Using data from pre-, mid- and post-implementation of the MPAs for control and project villages, we found little empirical evidence that impacts on five key socioeconomic indicators related to poverty differed according to social subgroup. We found suggestive empirical evidence that the effect of the MPAs on environmental knowledge differed by age and religion; over the medium and long terms, younger people and Muslims showed greater improvements compared with older people and Christians, respectively. PMID:26460130

SU-F-J-169: A Feasibility Study of Using MRI Alone in Abdominal Radiotherapy

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

Zawisza, I; Hsu, S; Peng, Q

Purpose: To demonstrate the feasibility of a MRI alone workflow to support treatment planning and image guidance for abdominal radiotherapy. Methods: Abdominal MR images (in-phase/out-phase/fat/water) were acquired for a patient with breath-hold using a Dixon pulse sequence. Air masks were created on in-phase images using intensity thresholding and morphological processing methods in order to separate air from bone. Pseudo-CT and DRRs were generated using a published method. To investigate the effect of heterogeneity corrections on dose calculations using pseudo-CT, three different plans (3-field 3D, 5-field IMRT and 2-arc VMAT) were performed to mimic pancreatic treatments (1.8Gy/fraction over 28 fractions). Results:more » The DRRs created from pseudo-CT were of comparable quality as those created from CT. Comparing dose calculations with and without heterogeneity corrections between the 3 different plans, the biggest dosimetric differences were seen in the VMAT plan where modulation must occur across air-tissue interfaces such as those of the stomach and bowel. The DVHs for the VMAT plan showed ∼84cc difference at V50Gy in the small bowel. In terms of pseudo-CT quality, some small volumes of air in the bowel and stomach were misclassified as bone. The VMAT plan was re-optimized on pseudo-CT with 0 HU in the misclassified areas. The V50Gy in the small bowel differed by ∼90cc between the new VMAT plan with and without heterogeneity corrections. Conclusion: We found that the use of MRI alone is feasible for abdominal treatment planning and image guidance. A difference between calculations with and without heterogeneity corrections was found that is most pronounced for VMAT where the traversal of air-tissue interfaces is unavoidable. Future work will be performed to minimize misclassification between bone and air.« less

Mapping Fearscapes of a Mammalian Herbivore using Terrestrial LiDAR and UAV Imagery

NASA Astrophysics Data System (ADS)

Olsoy, P.; Nobler, J. D.; Forbey, J.; Rachlow, J. L.; Burgess, M. A.; Glenn, N. F.; Shipley, L. A.

2013-12-01

Concealment allows prey animals to remain hidden from a predator and can influence both real and perceived risks of predation. The heterogeneous nature of vegetative structure can create a variable landscape of concealment - a 'fearscape' - that may influence habitat quality and use by prey. Traditional measurements of concealment rely on a limited number of distances, heights, and vantage points, resulting in small snapshots of concealment available to a prey animal. Our objective was to demonstrate the benefits of emerging remote sensing techniques to map fearscapes for pygmy rabbits (Brachylagus idahoensis) in sagebrush steppe habitat across a continuous range of scales. Specifically, we used vegetation height rasters derived from terrestrial laser scanning (TLS) to create viewsheds from multiple vantage points, representing predator visibility. The sum of all the viewsheds modeled horizontal concealment of prey at both the shrub and patch scales. We also used a small, unmanned aerial vehicle (UAV) to determine vertical concealment at a habitat scale. Terrestrial laser scanning provided similar estimates of horizontal concealment at the shrub scale when compared to photographic methods (R2 = 0.85). Both TLS and UAV provide the potential to quantify concealment of prey from multiple distances, heights, or vantage points, allowing the creation of a manipulable fearscape map that can be correlated with habitat use by prey animals. The predictive power of such a map also could identify shrubs or patches for fine scale nutritional and concealment analysis for future investigation and conservation efforts. Fearscape map at the mound-scale. Viewsheds were calculated from 100 equally spaced observer points located 4 m from the closest on-mound sagebrush of interest. Red areas offer low concealment, while green areas provide high concealment.

Simulation modeling to understand how selective foraging by beaver can drive the structure and function of a willow community

USGS Publications Warehouse

Peinetti, H.R.; Baker, B.W.; Coughenour, M.B.

2009-01-01

Beaver-willow (Castor-Salix) communities are a unique and vital component of healthy wetlands throughout the Holarctic region. Beaver selectively forage willow to provide fresh food, stored winter food, and construction material. The effects of this complex foraging behavior on the structure and function of willow communities is poorly understood. Simulation modeling may help ecologists understand these complex interactions. In this study, a modified version of the SAVANNA ecosystem model was developed to better understand how beaver foraging affects the structure and function of a willow community in a simulated riparian ecosystem in Rocky Mountain National Park, Colorado (RMNP). The model represents willow in terms of plant and stem dynamics and beaver foraging in terms of the quantity and quality of stems cut to meet the energetic and life history requirements of beaver. Given a site where all stems were equally available, the model suggested a simulated beaver family of 2 adults, 2 yearlings, and 2 kits required a minimum of 4 ha of willow (containing about10 stems m-2) to persist in a steady-state condition. Beaver created a willow community where the annual net primary productivity (ANPP) was 2 times higher and plant architecture was more diverse than the willow community without beaver. Beaver foraging created a plant architecture dominated by medium size willow plants, which likely explains how beaver can increase ANPP. Long-term simulations suggested that woody biomass stabilized at similar values even though availability differed greatly at initial condition. Simulations also suggested that willow ANPP increased across a range of beaver densities until beaver became food limited. Thus, selective foraging by beaver increased productivity, decreased biomass, and increased structural heterogeneity in a simulated willow community.

Building a National Framework for Adolescent and Young Adult Hematology and Oncology and Transition from Pediatric to Adult Care: Report of the Inaugural Meeting of the "AjET" Working Group of the German Society for Pediatric Oncology and Hematology.

PubMed

Escherich, Gabriele; Bielack, Stefan; Maier, Stephan; Braungart, Ralf; Brümmendorf, Tim H; Freund, Mathias; Grosse, Regine; Hoferer, Anette; Kampschulte, Rebecca; Koch, Barbara; Lauten, Melchior; Milani, Valeria; Ross, Henning; Schilling, Freimut; Wöhrle, Dieter; Cario, Holger; Dirksen, Uta

2017-06-01

Adolescents and young adults (AYAs) with hemato-oncological problems constitute a heterogenous group with characteristic particularities, specific needs, and age-related clinical and unique psychosocial features. Strong collaboration between pediatric and adult hemato-oncology settings is essential to address their needs appropriately. This is not only true for patients who first become ill during adolescence or young adulthood, but equally so for people who contract hemato-oncological diseases congenitally or as younger children and who are now becoming old enough to leave the pediatric setting and have to transit into "adult" medical care. Efforts to create environments that meet the specific needs of the AYA population affected by hemato-oncological diseases have been initiated in many countries. Due to international variations between societies in general and healthcare infrastructures in particular, the challenges posed to creating such environments vary considerably from country to country. Aiming at addressing these on a national basis for Germany, a dedicated Working Group on Adolescents, Young Adults, and Transition (Arbeitsgemeinschaft Adoleszenten, junge Erwachsene, Transition, AjET) was established. This meeting report depicts the content and discussions of the first interdisciplinary conference on treatment, transition, and long-term follow-up in AYAs with cancer or chronic/inborn hematological diseases. The AjET group of the German Society for Pediatric Oncology and Hematology (GPOH) intends to increase the national awareness for AYAs; strengthen the collaboration of pediatric and adult care givers; and initiate, promote, and coordinate collaborative activities in the fields of basic and translational research, clinical care, and long-term follow-up aimed at improving the current situation.

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.

Simulation study of axial ultrasound transmission in heterogeneous cortical bone model

NASA Astrophysics Data System (ADS)

Takano, Koki; Nagatani, Yoshiki; Matsukawa, Mami

2017-07-01

Ultrasound propagation in a heterogeneous cortical bone was studied. Using a bovine radius, the longitudinal wave velocity distribution in the axial direction was experimentally measured in the MHz range. The bilinear interpolation and piecewise cubic Hermite interpolation methods were applied to create a three-dimensional (3D) precise velocity model of the bone using experimental data. By assuming the uniaxial anisotropy of the bone, the distributions of all elastic moduli of a 3D heterogeneous model were estimated. The elastic finite-difference time-domain method was used to simulate axial ultrasonic wave propagation. The wave propagation in the initial model was compared with that in the thinner model, where the inner part of the cortical bone model was removed. The wave front of the first arriving signal (FAS) slightly depended on the heterogeneity in each model. Owing to the decrease in bone thickness, the propagation behavior also changed and the FAS velocity clearly decreased.

Physical Heterogeneity and Aquatic Community Function in River Networks

EPA Science Inventory

The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological...

SU-E-T-513: Investigating Dose of Internal Target Volume After Correcting for Tissue Heterogeneity in SBRT Lung Plans with Homogeneity Calculation

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

Qi, P; Zhuang, T; Magnelli, A

2015-06-15

Purpose It was recommended to use the prescription of 54 Gy/3 with heterogeneity corrections for previously established dose scheme of 60 Gy/3 with homogeneity calculation. This study is to investigate dose coverage for the internal target volume (ITV) with and without heterogeneity correction. Methods Thirty patients who received stereotactic body radiotherapy (SBRT) to a dose of 60 Gy in 3 fractions with homogeneous planning for early stage non-small-cell lung cancer (NSCLC) were selected. ITV was created either from 4DCT scans or a fusion of multi-phase respiratory scans. Planning target volume (PTV) was a 5 mm expansion of the ITV. Formore » this study, we recalculated homogeneous clinical plans using heterogeneity corrections with monitor units set as clinically delivered. All plans were calculated with 3 mm dose grids and collapsed cone convolution algorithm. To account for uncertainties from tumor delineation and image-guided radiotherapy, a structure ITV2mm was created by expanding ITV with 2 mm margins. Dose coverage to the PTV, ITV and ITV2mm were compared with a student paired t-test. Results With heterogeneity corrections, the PTV V60Gy decreased by 10.1% ± 18.4% (p<0.01) while the maximum dose to the PTV increased by 3.7 ± 4.3% (p<0.01). With and without corrections, D99% was 65.8 ± 4.0 Gy and 66.7 ± 4.8 Gy (p=0.15) for the ITV, and 63.9 ± 3.4 Gy and 62.9 ± 4.6 Gy for the ITV2mm (p=0.22), respectively. The mean dose to the ITV and ITV2mm increased 3.6% ± 4.7% (p<0.01) and 2.3% ± 5.2% (p=0.01) with heterogeneity corrections. Conclusion After heterogeneity correction, the peripheral coverage of the PTV decreased to approximately 54 Gy, but D99% of the ITV and ITV2mm was unchanged and the mean dose to the ITV and ITV2mm was increased. Clinical implication of these results requires more investigation.« less

TOWARDS A MULTI-SCALE AGENT-BASED PROGRAMMING LANGUAGE METHODOLOGY

PubMed Central

Somogyi, Endre; Hagar, Amit; Glazier, James A.

2017-01-01

Living tissues are dynamic, heterogeneous compositions of objects, including molecules, cells and extra-cellular materials, which interact via chemical, mechanical and electrical process and reorganize via transformation, birth, death and migration processes. Current programming language have difficulty describing the dynamics of tissues because: 1: Dynamic sets of objects participate simultaneously in multiple processes, 2: Processes may be either continuous or discrete, and their activity may be conditional, 3: Objects and processes form complex, heterogeneous relationships and structures, 4: Objects and processes may be hierarchically composed, 5: Processes may create, destroy and transform objects and processes. Some modeling languages support these concepts, but most cannot translate models into executable simulations. We present a new hybrid executable modeling language paradigm, the Continuous Concurrent Object Process Methodology (CCOPM) which naturally expresses tissue models, enabling users to visually create agent-based models of tissues, and also allows computer simulation of these models. PMID:29282379

TOWARDS A MULTI-SCALE AGENT-BASED PROGRAMMING LANGUAGE METHODOLOGY.

PubMed

Somogyi, Endre; Hagar, Amit; Glazier, James A

2016-12-01

Living tissues are dynamic, heterogeneous compositions of objects , including molecules, cells and extra-cellular materials, which interact via chemical, mechanical and electrical process and reorganize via transformation, birth, death and migration processes . Current programming language have difficulty describing the dynamics of tissues because: 1: Dynamic sets of objects participate simultaneously in multiple processes, 2: Processes may be either continuous or discrete, and their activity may be conditional, 3: Objects and processes form complex, heterogeneous relationships and structures, 4: Objects and processes may be hierarchically composed, 5: Processes may create, destroy and transform objects and processes. Some modeling languages support these concepts, but most cannot translate models into executable simulations. We present a new hybrid executable modeling language paradigm, the Continuous Concurrent Object Process Methodology ( CCOPM ) which naturally expresses tissue models, enabling users to visually create agent-based models of tissues, and also allows computer simulation of these models.

Analyzing the Heterogeneous Hierarchy of Cultural Heritage Materials: Analytical Imaging.

PubMed

Trentelman, Karen

2017-06-12

Objects of cultural heritage significance are created using a wide variety of materials, or mixtures of materials, and often exhibit heterogeneity on multiple length scales. The effective study of these complex constructions thus requires the use of a suite of complementary analytical technologies. Moreover, because of the importance and irreplaceability of most cultural heritage objects, researchers favor analytical techniques that can be employed noninvasively, i.e., without having to remove any material for analysis. As such, analytical imaging has emerged as an important approach for the study of cultural heritage. Imaging technologies commonly employed, from the macroscale through the micro- to nanoscale, are discussed with respect to how the information obtained helps us understand artists' materials and methods, the cultures in which the objects were created, how the objects may have changed over time, and importantly, how we may develop strategies for their preservation.

A Method to Represent Heterogeneous Materials for Rapid Prototyping: The Matryoshka Approach.

PubMed

Lei, Shuangyan; Frank, Matthew C; Anderson, Donald D; Brown, Thomas D

The purpose of this paper is to present a new method for representing heterogeneous materials using nested STL shells, based, in particular, on the density distributions of human bones. Nested STL shells, called Matryoshka models, are described, based on their namesake Russian nesting dolls. In this approach, polygonal models, such as STL shells, are "stacked" inside one another to represent different material regions. The Matryoshka model addresses the challenge of representing different densities and different types of bone when reverse engineering from medical images. The Matryoshka model is generated via an iterative process of thresholding the Hounsfield Unit (HU) data using computed tomography (CT), thereby delineating regions of progressively increasing bone density. These nested shells can represent regions starting with the medullary (bone marrow) canal, up through and including the outer surface of the bone. The Matryoshka approach introduced can be used to generate accurate models of heterogeneous materials in an automated fashion, avoiding the challenge of hand-creating an assembly model for input to multi-material additive or subtractive manufacturing. This paper presents a new method for describing heterogeneous materials: in this case, the density distribution in a human bone. The authors show how the Matryoshka model can be used to plan harvesting locations for creating custom rapid allograft bone implants from donor bone. An implementation of a proposed harvesting method is demonstrated, followed by a case study using subtractive rapid prototyping to harvest a bone implant from a human tibia surrogate.

Dynamic Distributed Cooperative Control of Multiple Heterogeneous Resources

DTIC Science & Technology

2012-10-01

of the UAVs to maximize the total sensor footprint over the region of interest. The algorithm utilized to solve this problem was based on sampling a...and moving obstacles. Obstacle positions were assumed known a priori. Kingston and Beard [22] presented an algorithm to keep moving UAVs equally spaced...Planning Algorithms , Cambridge University Press, 2006. 11. Ma, C. S. and Miller, R. H., “Mixed integer linear programming trajectory generation for

What information is provided in transcripts and Medical Student Performance Records from Canadian Medical Schools? A retrospective cohort study.

PubMed

Robins, Jason A; McInnes, Matthew D F; Esmail, Kaisra

2014-01-01

Resident selection committees must rely on information provided by medical schools in order to evaluate candidates. However, this information varies between institutions, limiting its value in comparing individuals and fairly assessing their quality. This study investigates what is included in candidates' documentation, the heterogeneity therein, as well as its objective data. Samples of recent transcripts and Medical Student Performance Records were anonymised prior to evaluation. Data were then extracted by two independent reviewers blinded to the submitting university, assessing for the presence of pre-selected criteria; disagreement was resolved through consensus. The data were subsequently analysed in multiple subgroups. Inter-rater agreement equalled 92%. Inclusion of important criteria varied by school, ranging from 22.2% inclusion to 70.4%; the mean equalled 47.4%. The frequency of specific criteria was highly variable as well. Only 17.7% of schools provided any basis for comparison of academic performance; the majority detailed only status regarding pass or fail, without any further qualification. Considerable heterogeneity exists in the information provided in official medical school documentation, as well as markedly little objective data. Standardization may be necessary in order to facilitate fair comparison of graduates from different institutions. Implementation of objective data may allow more effective intra- and inter-scholastic comparison.

Modelling solute dispersion in periodic heterogeneous porous media: Model benchmarking against intermediate scale experiments

NASA Astrophysics Data System (ADS)

Majdalani, Samer; Guinot, Vincent; Delenne, Carole; Gebran, Hicham

2018-06-01

This paper is devoted to theoretical and experimental investigations of solute dispersion in heterogeneous porous media. Dispersion in heterogenous porous media has been reported to be scale-dependent, a likely indication that the proposed dispersion models are incompletely formulated. A high quality experimental data set of breakthrough curves in periodic model heterogeneous porous media is presented. In contrast with most previously published experiments, the present experiments involve numerous replicates. This allows the statistical variability of experimental data to be accounted for. Several models are benchmarked against the data set: the Fickian-based advection-dispersion, mobile-immobile, multirate, multiple region advection dispersion models, and a newly proposed transport model based on pure advection. A salient property of the latter model is that its solutions exhibit a ballistic behaviour for small times, while tending to the Fickian behaviour for large time scales. Model performance is assessed using a novel objective function accounting for the statistical variability of the experimental data set, while putting equal emphasis on both small and large time scale behaviours. Besides being as accurate as the other models, the new purely advective model has the advantages that (i) it does not exhibit the undesirable effects associated with the usual Fickian operator (namely the infinite solute front propagation speed), and (ii) it allows dispersive transport to be simulated on every heterogeneity scale using scale-independent parameters.

Optimized ECC Implementation for Secure Communication between Heterogeneous IoT Devices.

PubMed

Marin, Leandro; Pawlowski, Marcin Piotr; Jara, Antonio

2015-08-28

The Internet of Things is integrating information systems, places, users and billions of constrained devices into one global network. This network requires secure and private means of communications. The building blocks of the Internet of Things are devices manufactured by various producers and are designed to fulfil different needs. There would be no common hardware platform that could be applied in every scenario. In such a heterogeneous environment, there is a strong need for the optimization of interoperable security. We present optimized elliptic curve Cryptography algorithms that address the security issues in the heterogeneous IoT networks. We have combined cryptographic algorithms for the NXP/Jennic 5148- and MSP430-based IoT devices and used them to created novel key negotiation protocol.

Design of a digital and self-reported food frequency questionnaire to estimate food consumption in adolescents and young adults: birth cohorts at Pelotas, Rio Grande do Sul, Brazil.

PubMed

Schneider, Bruna Celestino; Motta, Janaína Vieira Dos Santos; Muniz, Ludmila Correa; Bielemann, Renata Moraes; Madruga, Samanta Winck; Orlandi, Silvana Paiva; Gigante, Denise Petrucci; Assunção, Maria Cecília Formoso

2016-01-01

Methodological paper aiming to describe the development of a digital and self-reported food frequency questionnaire (FFQ), created to the 1982 and 1993 Pelotas Birth Cohorts. The instrument was created based on FFQs previously applied to subjects belonging to both cohorts in the 2004 and 2008 follow-ups. The FFQ was developed including 88 foods and/or meals where frequencies were clustered from a minimum of never or once/month to a maximum of greater than or equal to 5 times/day. The closed options related to portions were based on a 24-hour recall previously asked to a subsample from the 1993 cohort. Three options for portions were created: equal to, less than or greater than. Equal to portion was described based on the 50 percentile of each food consumed reported in a 24-hour recall. Photographs of portions related to the 50 percentile for each food were also included in the software. This digital FFQ included food and meals based on the needs of current researches. The layout of the software was attractive to the staff members as well as to the cohort members. The responding time was 12 minutes and the software allowed several individuals to use it at the same time. Moreover, this instrument dismissed interviewers and double data entry. It is recommended the use of the same strategy in other studies, adapted to different contexts and situations.

Application of the dynamically allocated virtual clustering management system to emulated tactical network experimentation

NASA Astrophysics Data System (ADS)

Marcus, Kelvin

2014-06-01

The U.S Army Research Laboratory (ARL) has built a "Network Science Research Lab" to support research that aims to improve their ability to analyze, predict, design, and govern complex systems that interweave the social/cognitive, information, and communication network genres. Researchers at ARL and the Network Science Collaborative Technology Alliance (NS-CTA), a collaborative research alliance funded by ARL, conducted experimentation to determine if automated network monitoring tools and task-aware agents deployed within an emulated tactical wireless network could potentially increase the retrieval of relevant data from heterogeneous distributed information nodes. ARL and NS-CTA required the capability to perform this experimentation over clusters of heterogeneous nodes with emulated wireless tactical networks where each node could contain different operating systems, application sets, and physical hardware attributes. Researchers utilized the Dynamically Allocated Virtual Clustering Management System (DAVC) to address each of the infrastructure support requirements necessary in conducting their experimentation. The DAVC is an experimentation infrastructure that provides the means to dynamically create, deploy, and manage virtual clusters of heterogeneous nodes within a cloud computing environment based upon resource utilization such as CPU load, available RAM and hard disk space. The DAVC uses 802.1Q Virtual LANs (VLANs) to prevent experimentation crosstalk and to allow for complex private networks. Clusters created by the DAVC system can be utilized for software development, experimentation, and integration with existing hardware and software. The goal of this paper is to explore how ARL and the NS-CTA leveraged the DAVC to create, deploy and manage multiple experimentation clusters to support their experimentation goals.

Influence of macrofaunal assemblages and environmental heterogeneity on microphytobenthic production in experimental systems

PubMed Central

Dyson, Kirstie E; Bulling, Mark T; Solan, Martin; Hernandez-Milian, Gema; Raffaelli, David G; White, Piran C.L; Paterson, David M

2007-01-01

Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, rapid response times and the well-understood effects of macrofauna on sediment processes. Here, the influence of heterogeneity on microphytobenthic production in synthetic estuarine assemblages is examined. Heterogeneity was created by enriching patches of sediment with detrital algae (Enteromorpha intestinalis) to provide a source of allochthonous organic matter. A gradient of species density for four numerically dominant intertidal macrofauna (Hediste diversicolor, Hydrobia ulvae, Corophium volutator, Macoma balthica) was constructed, and microphytobenthic biomass at the sediment surface was measured. Statistical analysis using generalized least squares regression indicated that heterogeneity within our system was a significant driving factor that interacted with macrofaunal density and species identity. Microphytobenthic biomass was highest in enriched patches, suggesting that nutrients were obtained locally from the sediment–water interface and not from the water column. Our findings demonstrate that organic enrichment can cause the development of heterogeneity which influences infaunal bioturbation and consequent nutrient generation, a driver of microphytobenthic production. PMID:17698480

Influence of macrofaunal assemblages and environmental heterogeneity on microphytobenthic production in experimental systems.

PubMed

Dyson, Kirstie E; Bulling, Mark T; Solan, Martin; Hernandez-Milian, Gema; Raffaelli, David G; White, Piran C L; Paterson, David M

2007-10-22

Despite the complexity of natural systems, heterogeneity caused by the fragmentation of habitats has seldom been considered when investigating ecosystem processes. Empirical approaches that have included the influence of heterogeneity tend to be biased towards terrestrial habitats; yet marine systems offer opportunities by virtue of their relative ease of manipulation, rapid response times and the well-understood effects of macrofauna on sediment processes. Here, the influence of heterogeneity on microphytobenthic production in synthetic estuarine assemblages is examined. Heterogeneity was created by enriching patches of sediment with detrital algae (Enteromorpha intestinalis) to provide a source of allochthonous organic matter. A gradient of species density for four numerically dominant intertidal macrofauna (Hediste diversicolor, Hydrobia ulvae, Corophium volutator, Macoma balthica) was constructed, and microphytobenthic biomass at the sediment surface was measured. Statistical analysis using generalized least squares regression indicated that heterogeneity within our system was a significant driving factor that interacted with macrofaunal density and species identity. Microphytobenthic biomass was highest in enriched patches, suggesting that nutrients were obtained locally from the sediment-water interface and not from the water column. Our findings demonstrate that organic enrichment can cause the development of heterogeneity which influences infaunal bioturbation and consequent nutrient generation, a driver of microphytobenthic production.

Mesoscale Computational Investigation of Shocked Heterogeneous Materials with Application to Large Impact Craters

NASA Technical Reports Server (NTRS)

Crawford, D. A.; Barnouin-Jha, O. S.; Cintala, M. J.

2003-01-01

The propagation of shock waves through target materials is strongly influenced by the presence of small-scale structure, fractures, physical and chemical heterogeneities. Pre-existing fractures often create craters that appear square in outline (e.g. Meteor Crater). Reverberations behind the shock from the presence of physical heterogeneity have been proposed as a mechanism for transient weakening of target materials. Pre-existing fractures can also affect melt generation. In this study, we are attempting to bridge the gap in numerical modeling between the micro-scale and the continuum, the so-called meso-scale. To accomplish this, we are developing a methodology to be used in the shock physics hydrocode (CTH) using Monte-Carlo-type methods to investigate the shock properties of heterogeneous materials. By comparing the results of numerical experiments at the micro-scale with experimental results and by using statistical techniques to evaluate the performance of simple constitutive models, we hope to embed the effect of physical heterogeneity into the field variables (pressure, stress, density, velocity) allowing us to directly imprint the effects of micro-scale heterogeneity at the continuum level without incurring high computational cost.

Modern aspects of homogeneous-heterogeneous reactions and variable thickness in nanofluids through carbon nanotubes

NASA Astrophysics Data System (ADS)

Hayat, Tasawar; Ahmed, Sohail; Muhammad, Taseer; Alsaedi, Ahmed

2017-10-01

This article examines homogeneous-heterogeneous reactions and internal heat generation in Darcy-Forchheimer flow of nanofluids with different base fluids. Flow is generated due to a nonlinear stretchable surface of variable thickness. The characteristics of nanofluid are explored using CNTs (single and multi walled carbon nanotubes). Equal diffusion coefficients are considered for both reactants and auto catalyst. The conversion of partial differential equations (PDEs) to ordinary differential equations (ODEs) is done via appropriate transformations. Optimal homotopy approach is implemented for solutions development of governing problems. Averaged square residual errors are computed. The optimal solution expressions of velocity, temperature and concentration are explored through plots by using several values of physical parameters. Further the coefficient of skin friction and local Nusselt number are examined through graphs.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

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

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. This approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

DOE PAGES

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.; ...

2016-09-08

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. Lastly, this approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Use of steric encumbrance to develop conjugated nanoporous polymers for metal-free catalytic hydrogenation

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

Tian, Chengcheng; Zhu, Xiang; Abney, Carter W.

The design and synthesis of metal-free heterogeneous catalysts for efficient hydrogenation remains a great challenge. Here we report a novel approach to create conjugated nanoporous polymers with efficient hydrogenation activities toward unsaturated ketones by leveraging the innate steric encumbrance. The steric bulk of the framework as well as the local sterics of the Lewis basic sites within the polymeric skeleton result in the generation of the putative catalyst. Lastly, this approach opens up new possibilities for the development of innovative metal-free heterogeneous catalysts.

Equality as a central concept of nursing ethics: a systematic literature review.

PubMed

Kangasniemi, Mari

2010-12-01

Equality is a central concept in the Western way of thinking and in health care. In ethics research within nursing science, equality is a key concept but the meaning of its contents is more or less presumptive. The purpose of this study was to define the concept of equality as a value of nursing ethics research. Data were collected through systematic literature review and analysed using deductive and inductive content analysis. Equality has been studied as a concept and in relation to ethical theories. In nursing ethics, research on equality on theoretical and functional level is presented. These levels consist of dimensions, i.e. themes, that equality is related to. The dimensions of the theoretical level are the equality of being, i.e. universal human value, and distributive equality, i.e. equal opportunities, circumstances and results. The dimensions of functional equality included themes such as critique of distributive equality, context, difference, power and care. Critique is aimed at incompatibility of theoretical level with practice. Context raises questions of each nursing situation in relation to equality. Variation within context is closely related to differences involving parties to nursing, and it is a starting point to questions of equality. Power is understood as comprising knowledge, skills and authority that create differences and questions of equality between nurses and patients and nurses and other professionals or students. Nursing as care always includes relationship between two or more persons and needs to be inspected from the point of view of equality. The concept of equality has been complex to achieve in practice. The dimensions of the levels of equality defined in this study provide an opportunity to reach a better understanding of equality in nursing ethics. There is still a great demand for more research on the concept of equality. © 2010 The Author. Scandinavian Journal of Caring Sciences © 2010 Nordic College of Caring Science.

Edge enhancement and image equalization by unsharp masking using self-adaptive photochromic filters.

PubMed

Ferrari, José A; Flores, Jorge L; Perciante, César D; Frins, Erna

2009-07-01

A new method for real-time edge enhancement and image equalization using photochromic filters is presented. The reversible self-adaptive capacity of photochromic materials is used for creating an unsharp mask of the original image. This unsharp mask produces a kind of self filtering of the original image. Unlike the usual Fourier (coherent) image processing, the technique we propose can also be used with incoherent illumination. Validation experiments with Bacteriorhodopsin and photochromic glass are presented.

78 FR 62955 - National Character Counts Week, 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-23

... Founders--that we are all created equal, that we possess certain unalienable rights, including the rights... United States of America. Nowhere is our Nation's strength more evident than in the men and women in...

Gender Differences in Sustained Attentional Control Relate to Gender Inequality across Countries

PubMed Central

Riley, Elizabeth; Okabe, Hidefusa; Germine, Laura; Wilmer, Jeremy; Esterman, Michael; DeGutis, Joseph

2016-01-01

Sustained attentional control is critical for everyday tasks and success in school and employment. Understanding gender differences in sustained attentional control, and their potential sources, is an important goal of psychology and neuroscience and of great relevance to society. We used a large web-based sample (n = 21,484, from testmybrain.org) to examine gender differences in sustained attentional control. Our sample included participants from 41 countries, allowing us to examine how gender differences in each country relate to national indices of gender equality. We found significant gender differences in certain aspects of sustained attentional control. Using indices of gender equality, we found that overall sustained attentional control performance was lower in countries with less equality and that there were greater gender differences in performance in countries with less equality. These findings suggest that creating sociocultural conditions which value women and men equally can improve a component of sustained attention and reduce gender disparities in cognition. PMID:27802294

Gender Differences in Sustained Attentional Control Relate to Gender Inequality across Countries.

PubMed

Riley, Elizabeth; Okabe, Hidefusa; Germine, Laura; Wilmer, Jeremy; Esterman, Michael; DeGutis, Joseph

2016-01-01

Sustained attentional control is critical for everyday tasks and success in school and employment. Understanding gender differences in sustained attentional control, and their potential sources, is an important goal of psychology and neuroscience and of great relevance to society. We used a large web-based sample (n = 21,484, from testmybrain.org) to examine gender differences in sustained attentional control. Our sample included participants from 41 countries, allowing us to examine how gender differences in each country relate to national indices of gender equality. We found significant gender differences in certain aspects of sustained attentional control. Using indices of gender equality, we found that overall sustained attentional control performance was lower in countries with less equality and that there were greater gender differences in performance in countries with less equality. These findings suggest that creating sociocultural conditions which value women and men equally can improve a component of sustained attention and reduce gender disparities in cognition.

Risk equalization and voluntary deductibles: a complex interaction.

PubMed

van Kleef, R C; Beck, K; van de Ven, W P M M; van Vliet, R C J A

2008-03-01

The presence of voluntary deductibles in the Swiss and Dutch mandatory health insurance has important implications for the respective risk equalization systems. In a theoretical analysis, we discuss the consequences of equalizing three types of expenditures: the net claims that are reimbursed by the insurer, the out-of-pocket expenditures and the expenditure savings due to moral hazard reduction. Equalizing only the net claims, as done in Switzerland, creates incentives for cream skimming and prevents insurers from incorporating out-of-pocket expenditures and moral hazard reductions into their premium structure. In an empirical analysis, we examine the effect of self-selection and conclude that the Swiss and Dutch risk equalization systems do not fully adjust for differences in health status between those who choose a deductible and those who do not. We discuss how this may lead to incentives for cream skimming and to a reduction of cross-subsidies from healthy to unhealthy individuals compared to a situation without voluntary deductibles.

Ponderomotive force on solitary structures created during radiation pressure acceleration of thin foils

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

Tripathi, Vipin K.; Sharma, Anamika

2013-05-15

We estimate the ponderomotive force on an expanded inhomogeneous electron density profile, created in the later phase of laser irradiated diamond like ultrathin foil. When ions are uniformly distributed along the plasma slab and electron density obeys the Poisson's equation with space charge potential equal to negative of ponderomotive potential, φ=−φ{sub p}=−(mc{sup 2}/e)(γ−1), where γ=(1+|a|{sup 2}){sup 1/2}, and |a| is the normalized local laser amplitude inside the slab; the net ponderomotive force on the slab per unit area is demonstrated analytically to be equal to radiation pressure force for both overdense and underdense plasmas. In case electron density is takenmore » to be frozen as a Gaussian profile with peak density close to relativistic critical density, the ponderomotive force has non-monotonic spatial variation and sums up on all electrons per unit area to equal radiation pressure force at all laser intensities. The same result is obtained for the case of Gaussian ion density profile and self consistent electron density profile, obeying Poisson's equation with φ=−φ{sub p}.« less

A tour of inequality

NASA Astrophysics Data System (ADS)

Eliazar, Iddo

2018-02-01

This paper presents a concise and up-to-date tour to the realm of inequality indices. Originally devised for socioeconomic applications, inequality indices gauge the divergence of wealth distributions in human societies from the socioeconomic 'ground state' of perfect equality, i.e. pure communism. Inequality indices are quantitative scores that take values in the unit interval, with the zero score characterizing perfect equality. In effect, inequality indices are applicable in the context of general distributions of sizes - non-negative quantities such as count, length, area, volume, mass, energy, and duration. For general size distributions, which are omnipresent in science and engineering, inequality indices provide multi-dimensional and infinite-dimensional quantifications of the inherent inequality - i.e., the statistical heterogeneity, the non-determinism, the randomness. This paper compactly describes the insights and the practical implementation of inequality indices.

Remote Tropospheric Radio Communication,

DTIC Science & Technology

1980-03-19

heterogeneities of the second form arp caused by turtulent air motion as a result cf the inequality of the earth’s surface, nonuniformity of its heating...practice are applied ancther characteristic of the variability of the frecuency characteristics cf signal, so-callei nonuniformity in band E. This...eXcied val,1o K. Howe er, frequency ctaracteristic has identical DOC =80025107 r1Gi ji" nonuniformity , if the ailitude ratio on the edges cf band is equal

Coordinating Representations

DTIC Science & Technology

2006-04-07

4 COGNITIVE THEORY OF INTERSUBJECTIVITY...adaptive component that is created and that the use of that component improves their performance. 2 Project Summary Objectives Develop cognitive theory of...distributed collaboration among a heterogeneous team of actors. Theory explains how collaborators share a common understanding of their cooperative

Sustainable Applications of Magnetic Nano-catalysts and Graphitic Carbon Nitrides (presentation)

EPA Science Inventory

Homogeneous catalysts, known for chemo-, regio- and enantioselectivity, have better contact with the reactants but the catalyst separation creates barriers. Heterogeneous systems enable better separation although at the cost of reduction in the availability of active sites. Becau...

Quantifying site-specific physical heterogeneity within an estuarine seascape

USGS Publications Warehouse

Kennedy, Cristina G.; Mather, Martha E.; Smith, Joseph M.

2017-01-01

Quantifying physical heterogeneity is essential for meaningful ecological research and effective resource management. Spatial patterns of multiple, co-occurring physical features are rarely quantified across a seascape because of methodological challenges. Here, we identified approaches that measured total site-specific heterogeneity, an often overlooked aspect of estuarine ecosystems. Specifically, we examined 23 metrics that quantified four types of common physical features: (1) river and creek confluences, (2) bathymetric variation including underwater drop-offs, (3) land features such as islands/sandbars, and (4) major underwater channel networks. Our research at 40 sites throughout Plum Island Estuary (PIE) provided solutions to two problems. The first problem was that individual metrics that measured heterogeneity of a single physical feature showed different regional patterns. We solved this first problem by combining multiple metrics for a single feature using a within-physical feature cluster analysis. With this approach, we identified sites with four different types of confluences and three different types of underwater drop-offs. The second problem was that when multiple physical features co-occurred, new patterns of total site-specific heterogeneity were created across the seascape. This pattern of total heterogeneity has potential ecological relevance to structure-oriented predators. To address this second problem, we identified sites with similar types of total physical heterogeneity using an across-physical feature cluster analysis. Then, we calculated an additive heterogeneity index, which integrated all physical features at a site. Finally, we tested if site-specific additive heterogeneity index values differed for across-physical feature clusters. In PIE, the sites with the highest additive heterogeneity index values were clustered together and corresponded to sites where a fish predator, adult striped bass (Morone saxatilis), aggregated in a related acoustic tracking study. In summary, we have shown general approaches to quantifying site-specific heterogeneity.

A new approach to network heterogeneity: Polymerization Induced Phase Separation in photo-initiated, free-radical methacrylic systems

PubMed Central

Szczepanski, Caroline R.; Pfeifer, Carmem S.; Stansbury, Jeffrey W.

2012-01-01

Non-reactive, thermoplastic prepolymers (poly- methyl, ethyl and butyl methacrylate) were added to a model homopolymer matrix composed of triethylene glycol dimethacrylate (TEGDMA) to form heterogeneous networks via polymerization induced phase separation (PIPS). PIPS creates networks with distinct phase structure that can partially compensate for volumetric shrinkage during polymerization through localized internal volume expansion. This investigation utilizes purely photo-initiated, free-radical systems, broadening the scope of applications for PIPS since these processing conditions have not been studied previously. The introduction of prepolymer into TEGDMA monomer resulted in stable, homogeneous monomer formulations, most of which underwent PIPS upon photo-irradiation, creating heterogeneous networks. During polymerization the presence of prepolymer enhanced autoacceleration, allowing for a more extensive ambient cure of the material. Phase separation, as characterized by dynamic changes in sample turbidity, was monitored simultaneously with monomer conversion and either preceded or was coincident with network gelation. Dynamic mechanical analysis shows a broadening of the tan delta peak and secondary peak formation, characteristic of phase-separated materials, indicating one phase rich in prepolymer and another depleted form upon phase separation. In certain cases, PIPS leads to an enhanced physical reduction of volumetric shrinkage, which is attractive for many applications including dental composite materials. PMID:23109733

Commercial Off-The-Shelf (COTS) Parts Risk and Reliability User and Application Guide

NASA Technical Reports Server (NTRS)

White, Mark

2017-01-01

All COTS parts are not created equal. Because they are not created equal, the notion that one can force the commercial industry to follow a set of military specifications and standards, along with the certifications, audits and qualification commitments that go with them, is unrealistic for the sale of a few parts. The part technologies that are Defense Logistics Agency (DLA) certified or Military Specification (MS) qualified, are several generations behind the state-of-the-art high-performance parts that are required for the compact, higher performing systems for the next generation of spacecraft and instruments. The majority of the part suppliers are focused on the portion of the market that is producing high-tech commercial products and systems. To that end, in order to compete in the high performance and leading edge advanced technological systems, an alternative approach to risk assessment and reliability prediction must be considered.

Optimized ECC Implementation for Secure Communication between Heterogeneous IoT Devices

PubMed Central

Marin, Leandro; Piotr Pawlowski, Marcin; Jara, Antonio

2015-01-01

The Internet of Things is integrating information systems, places, users and billions of constrained devices into one global network. This network requires secure and private means of communications. The building blocks of the Internet of Things are devices manufactured by various producers and are designed to fulfil different needs. There would be no common hardware platform that could be applied in every scenario. In such a heterogeneous environment, there is a strong need for the optimization of interoperable security. We present optimized elliptic curve Cryptography algorithms that address the security issues in the heterogeneous IoT networks. We have combined cryptographic algorithms for the NXP/Jennic 5148- and MSP430-based IoT devices and used them to created novel key negotiation protocol. PMID:26343677

A Method to Represent Heterogeneous Materials for Rapid Prototyping: The Matryoshka Approach

PubMed Central

Lei, Shuangyan; Frank, Matthew C.; Anderson, Donald D.; Brown, Thomas D.

2015-01-01

Purpose The purpose of this paper is to present a new method for representing heterogeneous materials using nested STL shells, based, in particular, on the density distributions of human bones. Design/methodology/approach Nested STL shells, called Matryoshka models, are described, based on their namesake Russian nesting dolls. In this approach, polygonal models, such as STL shells, are “stacked” inside one another to represent different material regions. The Matryoshka model addresses the challenge of representing different densities and different types of bone when reverse engineering from medical images. The Matryoshka model is generated via an iterative process of thresholding the Hounsfield Unit (HU) data using computed tomography (CT), thereby delineating regions of progressively increasing bone density. These nested shells can represent regions starting with the medullary (bone marrow) canal, up through and including the outer surface of the bone. Findings The Matryoshka approach introduced can be used to generate accurate models of heterogeneous materials in an automated fashion, avoiding the challenge of hand-creating an assembly model for input to multi-material additive or subtractive manufacturing. Originality/Value This paper presents a new method for describing heterogeneous materials: in this case, the density distribution in a human bone. The authors show how the Matryoshka model can be used to plan harvesting locations for creating custom rapid allograft bone implants from donor bone. An implementation of a proposed harvesting method is demonstrated, followed by a case study using subtractive rapid prototyping to harvest a bone implant from a human tibia surrogate. PMID:26120277

Optimized and parallelized implementation of the electronegativity equalization method and the atom-bond electronegativity equalization method.

PubMed

Vareková, R Svobodová; Koca, J

2006-02-01

The most common way to calculate charge distribution in a molecule is ab initio quantum mechanics (QM). Some faster alternatives to QM have also been developed, the so-called "equalization methods" EEM and ABEEM, which are based on DFT. We have implemented and optimized the EEM and ABEEM methods and created the EEM SOLVER and ABEEM SOLVER programs. It has been found that the most time-consuming part of equalization methods is the reduction of the matrix belonging to the equation system generated by the method. Therefore, for both methods this part was replaced by the parallel algorithm WIRS and implemented within the PVM environment. The parallelized versions of the programs EEM SOLVER and ABEEM SOLVER showed promising results, especially on a single computer with several processors (compact PVM). The implemented programs are available through the Web page http://ncbr.chemi.muni.cz/~n19n/eem_abeem.

Theoretical study of the acid-base properties of the montmorillonite/electrolyte interface: influence of the surface heterogeneity and ionic strength on the potentiometric titration curves.

PubMed

Zarzycki, Piotr; Thomas, Fabien

2006-10-15

The parallel shape of the potentiometric titration curves for montmorillonite suspension is explained using the surface complexation model and taking into account the surface heterogeneity. The homogeneous models give accurate predictions only if they assume unphysically large values of the equilibrium constants for the exchange process occurring on the basal plane. However, the assumption that the basal plane is energetically heterogeneous allows to fit the experimental data (reported by Avena and De Pauli [M. Avena, C.P. De Pauli, J. Colloid Interface Sci. 202 (1998) 195-204]) for reasonable values of exchange equilibrium constant equal to 1.26 (suggested by Fletcher and Sposito [P. Fletcher, G. Sposito, Clay Miner. 24 (1989) 375-391]). Moreover, we observed the typical behavior of point of zero net proton charge (pznpc) as a function of logarithm of the electrolyte concentration (log[C]). We showed that the slope of the linear dependence, pznpc=f(log[C]), is proportional to the number of isomorphic substitutions in the crystal phase, which was also observed in the experimental studies.

Voices from Networked Classrooms.

ERIC Educational Resources Information Center

Brownlee-Conyers, Jean; Kraber, Brenda

1996-01-01

In 1994, the Glenview (Illinois) Public Schools created three technology-rich educational environments (TREEs) that use alternative teaching and learning methods through networked communication technologies. Each setting consists of three teachers and about 75 heterogeneously grouped students (ages 9-12) who work collaboratively to solve problems…

A Theoretical Approach to Selection of a Biologically Active Substance in Ultra-Low Doses for Effective Action on a Biological System.

PubMed

Boldyreva, Liudmila Borisovna

2018-05-01

 An approach is offered to selecting a biologically active substance (BAS) in ultra-low dose for effective action on a biological system (BS). The technique is based on the assumption that BAS in ultra-low doses exerts action on BS by means of spin supercurrent emerging between the spin structure created by BAS, on the one hand, and the spin structure created by BS, on the other hand. According to modern quantum-mechanical concepts, these spin structures may be virtual particles pairs having precessing spin (that is, be essentially spin vortices in the physical vacuum) and created by the quantum entities that BAS and BS consist of. The action is effective provided there is equality of precession frequencies of spins in these spin structures.  In this work, some methods are considered for determining the precession frequencies of spins in virtual particles pairs: (1) determination of energy levels of quantum entities that BS and BAS consist of; (2) the use of spin-flip effect of the virtual particles pair spin, the effect being initiated by action of magnetic vector potential (the spin-flip effect takes place when the varied frequency of the magnetic vector potential equals the precession frequency of the spin); (3) determining the frequencies of photons effectively acting on BS.  It is shown that the effect of BAS in ultra-low doses on BS can be replaced by the effect of a beam of low-intensity photons, if the frequency of photons equals the precession frequency of spin in spin structures created by BS. Consequently, the color of bodies placed near a biological system is able to exert an effective action on the biological system: that is "color therapy" is possible. It is also supposed that the spin-flip effect may be used not only for determining the precession frequency of spin in spin structures created by BS but also for therapeutic action on biological systems. The Faculty of Homeopathy.

Surface roughness of novel resin composites polished with one-step systems.

PubMed

Ergücü, Z; Türkün, L S

2007-01-01

This study: 1) analyzed the surface roughness of five novel resin composites that contain nanoparticles after polishing with three different one-step systems and 2) evaluated the effectiveness of these polishers and their possible surface damage using scanning electron microscope (SEM) analysis. The resin composites evaluated in this study include CeramX, Filtek Supreme XT, Grandio, Premise and Tetric EvoCeram. A total of 100 discs (20/resin composites, 10 x 2 mm) were fabricated. Five specimens/resin composites cured under Mylar strips served as the control. The samples were polished for 30 seconds with PoGo, OptraPol and One Gloss discs at 15,000 rpm using a slow speed handpiece. The surfaces were tested for roughness (Ra) with a surface roughness tester and examined with SEM. One-way ANOVA was used for statistical analysis (p = 0.05). For all the composites tested, differences between the polishing systems were found to be significant (p < 0.05). For Filtek Supreme XT, Mylar and PoGo created equally smooth surfaces, while significantly rougher surfaces were obtained after OptraPol and One Gloss applications. For Grandio, Mylar and PoGo created equally smooth surfaces, while OptraPol and One Gloss produced equally rougher surfaces. Tetric EvoCeram exhibited the roughest surface with OptraPol, while no significant differences were found between Premise and CeramX. According to SEM images, OptraPol and One Gloss scratched and plucked the particles away from the surface, while PoGo created a uniform finish, although the roughness values were not the same for each composite. Effectiveness of the polishers seems to be material dependent.

Bursts of Vertex Activation and Epidemics in Evolving Networks

PubMed Central

Rocha, Luis E. C.; Blondel, Vincent D.

2013-01-01

The dynamic nature of contact patterns creates diverse temporal structures. In particular, empirical studies have shown that contact patterns follow heterogeneous inter-event time intervals, meaning that periods of high activity are followed by long periods of inactivity. To investigate the impact of these heterogeneities in the spread of infection from a theoretical perspective, we propose a stochastic model to generate temporal networks where vertices make instantaneous contacts following heterogeneous inter-event intervals, and may leave and enter the system. We study how these properties affect the prevalence of an infection and estimate , the number of secondary infections of an infectious individual in a completely susceptible population, by modeling simulated infections (SI and SIR) that co-evolve with the network structure. We find that heterogeneous contact patterns cause earlier and larger epidemics in the SIR model in comparison to homogeneous scenarios for a vast range of parameter values, while smaller epidemics may happen in some combinations of parameters. In the case of SI and heterogeneous patterns, the epidemics develop faster in the earlier stages followed by a slowdown in the asymptotic limit. For increasing vertex turnover rates, heterogeneous patterns generally cause higher prevalence in comparison to homogeneous scenarios with the same average inter-event interval. We find that is generally higher for heterogeneous patterns, except for sufficiently large infection duration and transmission probability. PMID:23555211

Magnetically assisted slip casting of bioinspired heterogeneous composites

NASA Astrophysics Data System (ADS)

Le Ferrand, Hortense; Bouville, Florian; Niebel, Tobias P.; Studart, André R.

2015-11-01

Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture.

The structure of Turkish trait-descriptive adjectives.

PubMed

Somer, O; Goldberg, L R

1999-03-01

This description of the Turkish lexical project reports some initial findings on the structure of Turkish personality-related variables. In addition, it provides evidence on the effects of target evaluative homogeneity vs. heterogeneity (e.g., samples of well-liked target individuals vs. samples of both liked and disliked targets) on the resulting factor structures, and thus it provides a first test of the conclusions reached by D. Peabody and L. R. Goldberg (1989) using English trait terms. In 2 separate studies, and in 2 types of data sets, clear versions of the Big Five factor structure were found. And both studies replicated and extended the findings of Peabody and Goldberg; virtually orthogonal factors of relatively equal size were found in the homogeneous samples, and a more highly correlated set of factors with relatively large Agreeableness and Conscientiousness dimensions was found in the heterogeneous samples.

Structural Health Monitoring for Heterogeneous Systems

DTIC Science & Technology

2006-06-30

composites, The 2 present work concentrates on the applicability of the MPD teclmnique to extract some feature components of "multiple-harmonic...actuator and sensor transfer finctions, rcspectivcly. The parameter CaI) is thc attenuation coefficieint at excitation frequency (Q and RAS is the...an cquilatcral triangle with a spacing of v0- R, and thc angles (t’,B6,Y) equal ton’/ 3 . 8 ag ID Is 20 25 Fig 2: L.:+ Su,,su, .....g distributio. Fig

A fractal analysis of protein to DNA binding kinetics using biosensors.

PubMed

Sadana, Ajit

2003-08-01

A fractal analysis of a confirmative nature only is presented for the binding of estrogen receptor (ER) in solution to its corresponding DNA (estrogen response element, ERE) immobilized on a sensor chip surface [J. Biol. Chem. 272 (1997) 11384], and for the cooperative binding of human 1,25-dihydroxyvitamin D(3) receptor (VDR) to DNA with the 9-cis-retinoic acid receptor (RXR) [Biochemistry 35 (1996) 3309]. Ligands were also used to modulate the first reaction. Data taken from the literature may be modeled by using a single- or a dual-fractal analysis. Relationships are presented for the binding rate coefficient as a function of either the analyte concentration in solution or the fractal dimension that exists on the biosensor surface. The binding rate expressions developed exhibit a wide range of dependence on the degree of heterogeneity that exists on the surface, ranging from sensitive (order of dependence equal to 1.202) to very sensitive (order of dependence equal to 12.239). In general, the binding rate coefficient increases as the degree of heterogeneity or the fractal dimension of the surface increases. The predictive relationships presented provide further physical insights into the reactions occurring on the biosensor surface. Even though these reactions are occurring on the biosensor surface, the relationships presented should assist in understanding and in possibly manipulating the reactions occurring on cellular surfaces.

Comparison of variance estimators for meta-analysis of instrumental variable estimates

PubMed Central

Schmidt, AF; Hingorani, AD; Jefferis, BJ; White, J; Groenwold, RHH; Dudbridge, F

2016-01-01

Abstract Background: Mendelian randomization studies perform instrumental variable (IV) analysis using genetic IVs. Results of individual Mendelian randomization studies can be pooled through meta-analysis. We explored how different variance estimators influence the meta-analysed IV estimate. Methods: Two versions of the delta method (IV before or after pooling), four bootstrap estimators, a jack-knife estimator and a heteroscedasticity-consistent (HC) variance estimator were compared using simulation. Two types of meta-analyses were compared, a two-stage meta-analysis pooling results, and a one-stage meta-analysis pooling datasets. Results: Using a two-stage meta-analysis, coverage of the point estimate using bootstrapped estimators deviated from nominal levels at weak instrument settings and/or outcome probabilities ≤ 0.10. The jack-knife estimator was the least biased resampling method, the HC estimator often failed at outcome probabilities ≤ 0.50 and overall the delta method estimators were the least biased. In the presence of between-study heterogeneity, the delta method before meta-analysis performed best. Using a one-stage meta-analysis all methods performed equally well and better than two-stage meta-analysis of greater or equal size. Conclusions: In the presence of between-study heterogeneity, two-stage meta-analyses should preferentially use the delta method before meta-analysis. Weak instrument bias can be reduced by performing a one-stage meta-analysis. PMID:27591262

Do Fraternities and Sororities Inhibit Intercultural Competence?

ERIC Educational Resources Information Center

Martin, Georgianna L.; Parker, Gene; Pascarella, Ernest T.; Blechschmidt, Sally

2015-01-01

This study explored the impact of fraternity and sorority affiliation on students' development of intercultural competence over four years of college at 11 institutions. Prior research admonishes fraternities and sororities for being largely heterogeneous organizations that detract from institutional efforts to create a culturally competent…

Low-temperature direct heterogeneous bonding of polyether ether ketone and platinum.

PubMed

Fu, Weixin; Shigetou, Akitsu; Shoji, Shuichi; Mizuno, Jun

2017-10-01

Direct heterogeneous bonding between polyether ether ketone (PEEK) and Pt was realized at the temperatures lower than 150°C. In order to create sufficient bondability to diverse materials, the surface was modified by vacuum ultraviolet (VUV) irradiation, which formed hydrate bridges. For comparison, direct bonding between surfaces atomically cleaned via Ar fast atom bombardment (FAB) was conducted in a vacuum. The VUV irradiation was found to be effective for creating an ultrathin hydrate bridge layer from the residual water molecules in the chamber. Tight bonds were formed through dehydration of the hydrate bridges by heating at 150°C, which also contributed to enhancing interdiffusion across the interface. The VUV-modified surfaces showed bondability as good as that of the FAB-treated surfaces, and the VUV-modified samples had shear strengths at the same level as those of FAB-treated surfaces. This technology will be of practical use in the packaging of lightweight, flexible biomedical devices. Copyright © 2017 Elsevier B.V. All rights reserved.

Numerical Generation of Dense Plume Fingers in Unsaturated Homogeneous Porous Media

NASA Astrophysics Data System (ADS)

Cremer, C.; Graf, T.

2012-04-01

In nature, the migration of dense plumes typically results in the formation of vertical plume fingers. Flow direction in fingers is downwards, which is counterbalanced by upwards flow of less dense fluid between fingers. In heterogeneous media, heterogeneity itself is known to trigger the formation of fingers. In homogeneous media, however, fingers are also created even if all grains had the same diameter. The reason is that pore-scale heterogeneity leading to different flow velocities also exists in homogeneous media due to two effects: (i) Grains of identical size may randomly arrange differently, e.g. forming tetrahedrons, hexahedrons or octahedrons. Each arrangement creates pores of varying diameter, thus resulting in different average flow velocities. (ii) Random variations of solute concentration lead to varying buoyancy effects, thus also resulting in different velocities. As a continuation of previously made efforts to incorporate pore-scale heterogeneity into fully saturated soil such that dense fingers are realistically generated (Cremer and Graf, EGU Assembly, 2011), the current paper extends the research scope from saturated to unsaturated soil. Perturbation methods are evaluated by numerically re-simulating a laboratory-scale experiment of plume transport in homogeneous unsaturated sand (Simmons et al., Transp. Porous Media, 2002). The following 5 methods are being discussed: (i) homogeneous sand, (ii) initial perturbation of solute concentration, (iii) spatially random, time-constant perturbation of solute source, (iv) spatially and temporally random noise of simulated solute concentration, and (v) random K-field that introduces physically insignificant but numerically significant heterogeneity. Results demonstrate that, as opposed to saturated flow, perturbing the solute source will not result in plume fingering. This is because the location of the perturbed source (domain top) and the location of finger generation (groundwater surface) do not coincide. Alternatively, similar to saturated flow, applying either a random concentration noise (iv) or a random K-field (v) generates realistic plume fingering. Future work will focus on the generation mechanisms of plume finger splitting.

Monte Carlo Investigation on the Effect of Heterogeneities on Strut Adjusted Volume Implant (SAVI) Dosimetry

NASA Astrophysics Data System (ADS)

Koontz, Craig

Breast cancer is the most prevalent cancer for women with more than 225,000 new cases diagnosed in the United States in 2012 (ACS, 2012). With the high prevalence, comes an increased emphasis on researching new techniques to treat this disease. Accelerated partial breast irradiation (APBI) has been used as an alternative to whole breast irradiation (WBI) in order to treat occult disease after lumpectomy. Similar recurrence rates have been found using ABPI after lumpectomy as with mastectomy alone, but with the added benefit of improved cosmetic and psychological results. Intracavitary brachytherapy devices have been used to deliver the APBI prescription. However, inability to produce asymmetric dose distributions in order to avoid overdosing skin and chest wall has been an issue with these devices. Multi-lumen devices were introduced to overcome this problem. Of these, the Strut-Adjusted Volume Implant (SAVI) has demonstrated the greatest ability to produce an asymmetric dose distribution, which would have greater ability to avoid skin and chest wall dose, and thus allow more women to receive this type of treatment. However, SAVI treatments come with inherent heterogeneities including variable backscatter due to the proximity to the tissue-air and tissue-lung interfaces and variable contents within the cavity created by the SAVI. The dose calculation protocol based on TG-43 does not account for heterogeneities and thus will not produce accurate dosimetry; however Acuros, a model-based dose calculation algorithm manufactured by Varian Medical Systems, claims to accurately account for heterogeneities. Monte Carlo simulation can calculate the dosimetry with high accuracy. In this thesis, a model of the SAVI will be created for Monte Carlo, specifically using MCNP code, in order to explore the affects of heterogeneities on the dose distribution. This data will be compared to TG-43 and Acuros calculated dosimetry to explore their accuracy.

Uneven-aged silviculture can enhance within stand heterogeneity and beetle diversity.

PubMed

Joelsson, Klara; Hjältén, Joakim; Work, Timothy

2018-01-01

Uneven-aged silviculture may better maintain species assemblages associated with old-growth forests than clear felling in part due to habitat heterogeneity created by maintaining standing retention strips adjacent to harvest trails. Retention strips and harvest trails created at the time of tree removal will likely have different microclimate and may harbor different assemblages. In some cases, the resultant stand heterogeneity associated with uneven-aged silviculture may be similar to natural small-scale disturbances. For beetles, increased light and temperature as well as potential access to young vegetation and deadwood substrates present in harvset trails may harbor beetle assemblages similar to those found in natural gaps. We sampled saproxylic beetles using flight intercept traps placed in harvest corridors and retention strips in 9 replicated uneven-aged spruce stands in central Sweden. We compared abundance, species richness and composition between harvest corridors and retention strips using generalized linear models, rarefaction, permutational multivariate analysis of variance and indicator species analysis. Canopy openness doubled, mean temperature and variability in daily temperature increased and humidity decreased on harvest trails. Beetle richness and abundance were greater in harvests trails than in retention strips and the beetle species composition differed significantly between habitats. Twenty-five species were associated with harvest trails, including three old-growth specialists such as Agathidium discoideum (Erichson), currently red-listed. We observed only one species, Xylechinus pilosus (Ratzeburg) that strongly favored retention strips. Harvest trails foster both open habitat species and old-growth species while retention strips harbored forest interior specialists. The combination of closed canopy, stratified forest in the retention strips and gap-like conditions on the harvest trails thus increases overall species richness and maintains more diverse assemblages at the stand level than would otherwise be seen in less heterogeneous stand types. This suggests that uneven-aged silviculture may provide added conservation benefits for both open habitat and old-growth specialists than silvicultural approaches that reduce stand heterogeneity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Reframing diversity: younq dentists and the numbers game.

PubMed

Lugo, Ivan

2005-01-01

Diversity is not the same thing as equality, although it creates pressure in that direction. As America becomes more diverse, we would like to see greater progress in access to education and equitable entry into the profession. The new dentist is increasingly both young and a member of a minority group. Foundations, such as Kellogg, Robert Wood Johnson, and the California Endowment, and the Hispanic, the National, and other ethnically affiliated dental associations and the American Association of Women Dentists are becoming a voice to convert diversity into equality.

Addressing poverty, education, and gender equality to improve the health of women worldwide.

PubMed

Tyer-Viola, Lynda A; Cesario, Sandra K

2010-01-01

The Millennium Development Goals (MDG) that target alleviating poverty, improving primary education, and fostering gender equity are important as a foundation to promote world health. Achieving these goals will create an environment for healthy lives for women and children. Poverty, education, and gender equality, although undeniably linked, need to be addressed individually. Nurses have the capacity and political will to address MDGs and to contribute to the health and well-being of the world population. © 2010 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.

Coarse-Grained Clustering Dynamics of Heterogeneously Coupled Neurons.

PubMed

Moon, Sung Joon; Cook, Katherine A; Rajendran, Karthikeyan; Kevrekidis, Ioannis G; Cisternas, Jaime; Laing, Carlo R

2015-12-01

The formation of oscillating phase clusters in a network of identical Hodgkin-Huxley neurons is studied, along with their dynamic behavior. The neurons are synaptically coupled in an all-to-all manner, yet the synaptic coupling characteristic time is heterogeneous across the connections. In a network of N neurons where this heterogeneity is characterized by a prescribed random variable, the oscillatory single-cluster state can transition-through [Formula: see text] (possibly perturbed) period-doubling and subsequent bifurcations-to a variety of multiple-cluster states. The clustering dynamic behavior is computationally studied both at the detailed and the coarse-grained levels, and a numerical approach that can enable studying the coarse-grained dynamics in a network of arbitrarily large size is suggested. Among a number of cluster states formed, double clusters, composed of nearly equal sub-network sizes are seen to be stable; interestingly, the heterogeneity parameter in each of the double-cluster components tends to be consistent with the random variable over the entire network: Given a double-cluster state, permuting the dynamical variables of the neurons can lead to a combinatorially large number of different, yet similar "fine" states that appear practically identical at the coarse-grained level. For weak heterogeneity we find that correlations rapidly develop, within each cluster, between the neuron's "identity" (its own value of the heterogeneity parameter) and its dynamical state. For single- and double-cluster states we demonstrate an effective coarse-graining approach that uses the Polynomial Chaos expansion to succinctly describe the dynamics by these quickly established "identity-state" correlations. This coarse-graining approach is utilized, within the equation-free framework, to perform efficient computations of the neuron ensemble dynamics.

Homogenizing bacterial cell factories: Analysis and engineering of phenotypic heterogeneity.

PubMed

Binder, Dennis; Drepper, Thomas; Jaeger, Karl-Erich; Delvigne, Frank; Wiechert, Wolfgang; Kohlheyer, Dietrich; Grünberger, Alexander

2017-07-01

In natural habitats, microbes form multispecies communities that commonly face rapidly changing and highly competitive environments. Thus, phenotypic heterogeneity has evolved as an innate and important survival strategy to gain an overall fitness advantage over cohabiting competitors. However, in defined artificial environments such as monocultures in small- to large-scale bioreactors, cell-to-cell variations are presumed to cause reduced production yields as well as process instability. Hence, engineering microbial production toward phenotypic homogeneity is a highly promising approach for synthetic biology and bioprocess optimization. In this review, we discuss recent studies that have unraveled the cell-to-cell heterogeneity observed during bacterial gene expression and metabolite production as well as the molecular mechanisms involved. In addition, current single-cell technologies are briefly reviewed with respect to their applicability in exploring cell-to-cell variations. We highlight emerging strategies and tools to reduce phenotypic heterogeneity in biotechnological expression setups. Here, strain or inducer modifications are combined with cell physiology manipulations to achieve the ultimate goal of equalizing bacterial populations. In this way, the majority of cells can be forced into high productivity, thus reducing less productive subpopulations that tend to consume valuable resources during production. Modifications in uptake systems, inducer molecules or nutrients represent valuable tools for diminishing heterogeneity. Finally, we address the challenge of transferring homogeneously responding cells into large-scale bioprocesses. Environmental heterogeneity originating from extrinsic factors such as stirring speed and pH, oxygen, temperature or nutrient distribution can significantly influence cellular physiology. We conclude that engineering microbial populations toward phenotypic homogeneity is an increasingly important task to take biotechnological productions to the next level of control. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Temperature and electrical memory of polymer fibers

NASA Astrophysics Data System (ADS)

Yuan, Jinkai; Zakri, Cécile; Grillard, Fabienne; Neri, Wilfrid; Poulin, Philippe

2014-05-01

We report in this work studies of the shape memory behavior of polymer fibers loaded with carbon nanotubes or graphene flakes. These materials exhibit enhanced shape memory properties with the generation of a giant stress upon shape recovery. In addition, they exhibit a surprising temperature memory with a peak of generated stress at a temperature nearly equal to the temperature of programming. This temperature memory is ascribed to the presence of dynamical heterogeneities and to the intrinsic broadness of the glass transition. We present recent experiments related to observables other than mechanical properties. In particular nanocomposite fibers exhibit variations of electrical conductivity with an accurate memory. Indeed, the rate of conductivity variations during temperature changes reaches a well defined maximum at a temperature equal to the temperature of programming. Such materials are promising for future actuators that couple dimensional changes with sensing electronic functionalities.

PeakML/mzMatch: a file format, Java library, R library, and tool-chain for mass spectrometry data analysis.

PubMed

Scheltema, Richard A; Jankevics, Andris; Jansen, Ritsert C; Swertz, Morris A; Breitling, Rainer

2011-04-01

The recent proliferation of high-resolution mass spectrometers has generated a wealth of new data analysis methods. However, flexible integration of these methods into configurations best suited to the research question is hampered by heterogeneous file formats and monolithic software development. The mzXML, mzData, and mzML file formats have enabled uniform access to unprocessed raw data. In this paper we present our efforts to produce an equally simple and powerful format, PeakML, to uniformly exchange processed intermediary and result data. To demonstrate the versatility of PeakML, we have developed an open source Java toolkit for processing, filtering, and annotating mass spectra in a customizable pipeline (mzMatch), as well as a user-friendly data visualization environment (PeakML Viewer). The PeakML format in particular enables the flexible exchange of processed data between software created by different groups or companies, as we illustrate by providing a PeakML-based integration of the widely used XCMS package with mzMatch data processing tools. As an added advantage, downstream analysis can benefit from direct access to the full mass trace information underlying summarized mass spectrometry results, providing the user with the means to rapidly verify results. The PeakML/mzMatch software is freely available at http://mzmatch.sourceforge.net, with documentation, tutorials, and a community forum.

Synergistic rate boosting of collagen fibrillogenesis in heterogeneous mixtures of crowding agents.

PubMed

Dewavrin, Jean-Yves; Abdurrahiem, Muhammed; Blocki, Anna; Musib, Mrinal; Piazza, Francesco; Raghunath, Michael

2015-03-26

The competition for access to space that arises between macromolecules is the basis of the macromolecular crowding phenomenon, known to modulate biochemical reactions in subtle ways. Crowding is a highly conserved physiological condition in and around cells in metazoans, and originates from a mixture of heterogeneous biomolecules. Here, using collagen fibrillogenesis as an experimental test platform and ideas from the theory of nonideal solutions, we show that an entropy-based synergy is created by a mixture of two different populations of artificial crowders, providing small crowders with extra volume occupancy when in the vicinity of bigger crowders. We present the physiological mechanism by which synergistic effects maximize volume exclusion with the minimum amount of heterogeneous crowders, demonstrating how the evolutionarily optimized crowded conditions found in vivo can be reproduced effectively in vitro.

Computationally Probing the Performance of Hybrid, Heterogeneous, and Homogeneous Iridium-Based Catalysts for Water Oxidation

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

García-Melchor, Max; Vilella, Laia; López, Núria

2016-04-29

An attractive strategy to improve the performance of water oxidation catalysts would be to anchor a homogeneous molecular catalyst on a heterogeneous solid surface to create a hybrid catalyst. The idea of this combined system is to take advantage of the individual properties of each of the two catalyst components. We use Density Functional Theory to determine the stability and activity of a model hybrid water oxidation catalyst consisting of a dimeric Ir complex attached on the IrO 2(110) surface through two oxygen atoms. We find that homogeneous catalysts can be bound to its matrix oxide without losing significant activity.more » Hence, designing hybrid systems that benefit from both the high tunability of activity of homogeneous catalysts and the stability of heterogeneous systems seems feasible.« less

Physical heterogeneity and aquatic community function in river networks: A case study from the Kanawha River Basin, USA

NASA Astrophysics Data System (ADS)

Thoms, M. C.; Delong, M. D.; Flotemersch, J. E.; Collins, S. E.

2017-08-01

The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological components is a central tenet for the interdisciplinary field of river science. Relationships between the physical heterogeneity and food web character of functional process zones (FPZs) - large tracts of river with a similar geomorphic character -in the Kanawha River (West Virginia, USA) are examined in this study. Food web character was measured as food chain length (FCL), which reflects ecological community structure and ecosystem function. Our results show that the same basal resources were present throughout the Kanawha River but that their assimilation into the aquatic food web by primary consumers differed between FPZs. Differences in the trophic position of higher consumers (fish) were also recorded between FPZs. Overall, the morphological heterogeneity and heterogeneity of the river bed sediment of FPZs were significantly correlated with FCL. Specifically, FCL increases with greater FPZ physical heterogeneity. The result of this study does not support the current paradigm that ecosystem size is the primary determinant of food web character in river ecosystems.

Statistics of chemical gradients in heterogeneous porous media

NASA Astrophysics Data System (ADS)

Le Borgne, T.; Huck, P. D.; Dentz, M.; Villermaux, E.

2017-12-01

As they create chemical disequilibrium and drive mixing fluxes, spatial gradients in solute concentrations exert a strong control on mixing and biogeochemical reactions in the subsurface. Large concentration gradients may develop in particular at interfaces between surface water and groundwater bodies, such as hyporheic zones, sea water - surface water interfaces or recharge areas. They also develop around contaminant plumes and fluids injected in subsurface operations. While macrodispersion theories predict smooth gradients, decaying in time due to dispersive dissipation, we show that concentration gradients are sustained by flow heterogeneity and have broadly distributed values. We present a general theory predicting the statistics of concentration gradients from the flow heterogeneity (Le Borgne et al., 2017). Analytical predictions are validated from high resolution simulations of transport in heterogeneous Darcy fields ranging from low to high permeability variances and low to high Peclet numbers. This modelling framework hence opens new perspectives for quantifying the dynamics of chemical gradients and the kinetics of associated biogeochemical reactions in heterogeneous subsurface environments.Reference:Le Borgne T., P.D. Huck, M. Dentz and E. Villermaux (2017) Scalar gradients in stirred mixtures and the deconstruction of random fields, J. of Fluid Mech. vol. 812, pp. 578-610 doi:10.1017/jfm.2016.799

WET sensor performance in organic and inorganic media with heterogeneous moisture distribution

USDA-ARS?s Scientific Manuscript database

Interest in electronic monitoring of soil water has grown as increased demand for water creates a greater need for effective water management. Relatively inexpensive commercial soil water sensors that use measured dielectric properties to calculate water content, have been developed to address this...

Culture Shock and Higher Education Performance: Implications for Teaching

ERIC Educational Resources Information Center

Kelly, Philip; Moogan, Yvonne

2012-01-01

The globalisation of higher education brings together learners and teachers from differing systems, creating a heterogeneous and diverse environment. Yet many higher education institutions typically rely on foreign students themselves to adapt to their new higher education environments. An investigation was undertaken as to whether traditional…

A Synthetic Model of Mass Persuasion.

ERIC Educational Resources Information Center

Kneupper, Charles W.; Underwood, Willard A.

Mass persuasion involves a message production process which significantly alters or reinforces an attitude, belief, or action of the members of a large, heterogeneous audience. A synthetic communication model for mass persuasion has been constructed which incorporates aspects of several models created to describe the process of effective…

MODELING SCALE-DEPENDENT LANDSCAPE PATTERN, DISPERSAL, AND CONNECTIVITY FROM THE PERSPECTIVE OF THE ORGANISM

EPA Science Inventory

Effects of fine- to broad-scale patterns of landscape heterogeneity on dispersal success were examined for organisms varying in life history traits. To systematically control spatial pattern, a landscape model was created by merging physiographically-based maps of simulated land...

2016 Summer Series - Elizabeth Nyamayaro - How to Create a Social Movement

NASA Image and Video Library

2016-07-14

Political activism is a tool used to create change, shining light on areas needing to be revisited. Humanity is at its best when we focus on our similarities while celebrating and promoting our differences; it is key to our survival. At NASA Ames, workforce diversity results in innovation and risk reduction. In her presentation, Ms. Elizabeth Nyamayaro will use the HeForShe movement as an example of factors that drive a successful movement and discuss gender equality.

Novel durable bio-photocatalyst purifiers, a non-heterogeneous mechanism: accelerated entrapped dye degradation into structural polysiloxane-shield nano-reactors.

PubMed

Dastjerdi, Roya; Montazer, Majid; Shahsavan, Shadi; Böttcher, Horst; Moghadam, M B; Sarsour, Jamal

2013-01-01

This research has designed innovative Ag/TiO(2) polysiloxane-shield nano-reactors on the PET fabric to develop novel durable bio-photocatalyst purifiers. To create these very fine nano-reactors, oppositely surface charged multiple size nanoparticles have been applied accompanied with a crosslinkable amino-functionalized polysiloxane (XPs) emulsion. Investigation of photocatalytic dye decolorization efficiency revealed a non-heterogeneous mechanism including an accelerated degradation of entrapped dye molecules into the structural polysiloxane-shield nano-reactors. In fact, dye molecules can be adsorbed by both Ag and XPs due to their electrostatic interactions and/or even via forming a complex with them especially with silver NPs. The absorbed dye and active oxygen species generated by TiO(2) were entrapped by polysiloxane shelter and the presence of silver nanoparticles further attract the negative oxygen species closer to the adsorbed dye molecules. In this way, the dye molecules are in close contact with concentrated active oxygen species into the created nano-reactors. This provides an accelerated degradation of dye molecules. This non-heterogeneous mechanism has been detected on the sample containing all of the three components. Increasing the concentration of Ag and XPs accelerated the second step beginning with an enhanced rate. Further, the treated samples also showed an excellent antibacterial activity. Copyright © 2012 Elsevier B.V. All rights reserved.

Spatiotemporal Heterogeneity of Dissolved Organic Carbon in Waters and Soils in a Snow-dominated Headwater Catchment: Investigations at Reynolds Creek Critical Zone Observatory, Owyhee County, Idaho

NASA Astrophysics Data System (ADS)

Radke, A. G.; Godsey, S.; Lohse, K. A.; Huber, D. P.; Patton, N. R.; Holbrook, S.

2017-12-01

The non-uniform distribution of precipitation in snowmelt-driven systems—the result of blowing and drifting snow—is a primary driver of spatial heterogeneity in vegetative communities and soil development. Snowdrifts may increase bedrock weathering below them, creating deeper soils and the potential for greater fracture flow. These snowdrift areas are also commonly more productive than the snow-starved, scoured areas where wind has removed snow. Warming-induced changes in the fraction of precipitation falling as snow, and therefore subject to drifting, may significantly affect carbon dynamics on multiple timescales. The focus of this study is to understand the coupled hydrological and carbon dynamics in a heterogeneous, drift-dominated watershed. We seek to determine the paths of soil water and groundwater in a small headwater catchment (Reynolds Mountain East, Reynolds Creek Critical Zone Observatory, Idaho, USA). Additionally, we anticipate quantifying the flux of dissolved organic carbon through these paths, and relate this to zones of greater vegetative productivity. We deduce likely flowpaths through a combination of soil water, groundwater, and precipitation characterization. Along a transect running from a snowdrift to the stream, we measure hydrometric and hydrochemical signatures of flow throughout the snowmelt period and summer. We then use end-member-mixing analysis to interpret flowpaths in light of inferred subsurface structure derived from drilling and electrical resistance tomography transects. Preliminary results from soil moisture sensors suggest that increased bedrock weathering creates pathways by which snowmelt bypasses portions of the soil, further increasing landscape heterogeneity. Further analysis will identify seasonal changes in carbon sourcing for this watershed, but initial indications are that spring streamwater is sourced primarily from soil water, with close associations between soil carbon and DOC.

Personalized-detailed clinical model for data interoperability among clinical standards.

PubMed

Khan, Wajahat Ali; Hussain, Maqbool; Afzal, Muhammad; Amin, Muhammad Bilal; Saleem, Muhammad Aamir; Lee, Sungyoung

2013-08-01

Data interoperability among health information exchange (HIE) systems is a major concern for healthcare practitioners to enable provisioning of telemedicine-related services. Heterogeneity exists in these systems not only at the data level but also among different heterogeneous healthcare standards with which these are compliant. The relationship between healthcare organization data and different heterogeneous standards is necessary to achieve the goal of data level interoperability. We propose a personalized-detailed clinical model (P-DCM) approach for the generation of customized mappings that creates the necessary linkage between organization-conformed healthcare standards concepts and clinical model concepts to ensure data interoperability among HIE systems. We consider electronic health record (EHR) standards, openEHR, and HL7 CDA instances transformation using P-DCM. P-DCM concepts associated with openEHR and HL7 CDA help in transformation of instances among these standards. We investigated two datasets: (1) data of 100 diabetic patients, including 50 each of type 1 and type 2, from a local hospital in Korea and (2) data of a single Alzheimer's disease patient. P-DCMs were created for both scenarios, which provided the basis for deriving instances for HL7 CDA and openEHR standards. For proof of concept, we present case studies of encounter information for type 2 diabetes mellitus patients and monitoring of daily routine activities of an Alzheimer's disease patient. These reflect P-DCM-based customized mappings generation with openEHR and HL7 CDA standards. Customized mappings are generated based on the relationship of P-DCM concepts with CDA and openEHR concepts. The objective of this work is to achieve semantic data interoperability among heterogeneous standards. This would lead to effective utilization of resources and allow timely information exchange among healthcare systems.

Personalized-Detailed Clinical Model for Data Interoperability Among Clinical Standards

PubMed Central

Khan, Wajahat Ali; Hussain, Maqbool; Afzal, Muhammad; Amin, Muhammad Bilal; Saleem, Muhammad Aamir

2013-01-01

Abstract Objective: Data interoperability among health information exchange (HIE) systems is a major concern for healthcare practitioners to enable provisioning of telemedicine-related services. Heterogeneity exists in these systems not only at the data level but also among different heterogeneous healthcare standards with which these are compliant. The relationship between healthcare organization data and different heterogeneous standards is necessary to achieve the goal of data level interoperability. We propose a personalized-detailed clinical model (P-DCM) approach for the generation of customized mappings that creates the necessary linkage between organization-conformed healthcare standards concepts and clinical model concepts to ensure data interoperability among HIE systems. Materials and Methods: We consider electronic health record (EHR) standards, openEHR, and HL7 CDA instances transformation using P-DCM. P-DCM concepts associated with openEHR and HL7 CDA help in transformation of instances among these standards. We investigated two datasets: (1) data of 100 diabetic patients, including 50 each of type 1 and type 2, from a local hospital in Korea and (2) data of a single Alzheimer's disease patient. P-DCMs were created for both scenarios, which provided the basis for deriving instances for HL7 CDA and openEHR standards. Results: For proof of concept, we present case studies of encounter information for type 2 diabetes mellitus patients and monitoring of daily routine activities of an Alzheimer's disease patient. These reflect P-DCM-based customized mappings generation with openEHR and HL7 CDA standards. Customized mappings are generated based on the relationship of P-DCM concepts with CDA and openEHR concepts. Conclusions: The objective of this work is to achieve semantic data interoperability among heterogeneous standards. This would lead to effective utilization of resources and allow timely information exchange among healthcare systems. PMID:23875730

SCALE-MODEL STUDIES OF MIXING IN DRINKING WATER STORAGE TANKS

EPA Science Inventory

Storage tanks and reservoirs are commonly used in drinking water distribution systems to equalize pumping requirements and operating pressures, and to provide emergency water for fire-fighting and pumping outages. Poor mixing in these structures can create pockets of older water...

Increasing Participation through Differentiation

ERIC Educational Resources Information Center

Christenson, Bridget; Wager, Anita A.

2012-01-01

One of the many challenges teachers face is trying to differentiate instruction so all students have equal opportunities to participate, learn, and engage. To provide guidelines for differentiated instruction in mathematics, staff from the Madison Metropolitan School District in Wisconsin created a pedagogical framework for teaching called…

Marked heterogeneity in growth characteristics of myoblast clonal cultures and myoblast mixed cultures obtained from the same individual.

PubMed

Maier, Andrea B; Cohen, Ron; Blom, Joke; van Heemst, Diana; Westendorp, Rudi G J

2012-01-01

Sarcopenia is defined as an age-related decrease in skeletal muscle mass and function while adjacent satellite cells are unable to compensate for this loss. However, myoblast cultures can be established even in the presence of sarcopenia. It is yet unknown whether satellite cells from failing muscle in older age are equally affected, as human satellite cells have been assessed using myoblast mixed cultures and not by using myoblast clonal cultures. We questioned to what extent myoblast mixed cultures reflect the in vivo characteristics of single satellite cells from adult skeletal muscle. We established a myoblast mixed culture and three myoblast clonal cultures out of the same muscle biopsy and cultured these cells for 100 days. Replicative capacity and oxidative stress resistance were compared. We found marked heterogeneity between the myoblast clonal cultures that all had a significantly lower replicative capacity when compared to the mixed culture. Replicative capacity of the clonal cultures was inversely related to the β-galactosidase activity after exposure to oxidative stress. Addition of L-carnosine enhanced the remaining replicative capacity in all cultures with a concomitant marginal decrease in β-galactosidase activity. It is concluded that myoblast mixed cultures in vitro do not reflect the marked heterogeneity between single isolated satellite cells. The consequences of the heterogeneity on muscle performance remain to be established. Copyright © 2011 S. Karger AG, Basel.

Effects of the heterogeneous landscape on a predator-prey system

NASA Astrophysics Data System (ADS)

Lee, Sang-Hee

2010-01-01

In order to understand how a heterogeneous landscape affects a predator-prey system, a spatially explicit lattice model consisting of predators, prey, grass, and landscape was constructed. The predators and preys randomly move on the lattice space and the grass grows in its neighboring site according to its growth probability. When predators and preys meet at the same site at the same time, a number of prey, equal to the number of predators are eaten. This rule was also applied to the relationship between the prey and grass. The predator (prey) could give birth to an offspring when it ate prey (grass), with a birth probability. When a predator or prey animal was initially introduced, or newly born, its health state was set at a given high value. This health state decreased by one with every time step. When the state of an animal decreased to less than zero, the animal died and was removed from the system. The heterogeneous landscape was characterized by parameter H, which controlled the heterogeneity according to the neutral model. The simulation results showed that H positively or negatively affected a predator’s survival, while its effect on prey and grass was less pronounced. The results can be understood by the disturbance of the balance between the prey and predator densities in the areas where the animals aggregated.

Badger (Taxidea taxus) disturbances increase soil heterogeneity in a degraded shrub-steppe ecosystem

USDA-ARS?s Scientific Manuscript database

In the western United States, overgrazing, weed invasion and wildfire have resulted in the conversion of shrub-steppe to annual grasslands, with substantial effects on ecosystem function. In these landscapes, badgers disturb large areas of soil while foraging for prey. Mounds created by badgers cont...

Herbaceous response to type and severity of disturbance

Treesearch

Katherine J. Elliott; Craig A. Harper; Beverly Collins

2011-01-01

The herbaceous layer varies with topographic heterogeneity and harbors the great majority of plant diversity in eastern deciduous forests. We described the interplay between disturbances, both natural and human-caused, and composition, dynamics, and diversity of herbaceous vegetation, especially those in early successional habitats. Management actions that create low...

Regenerating oak-dominated forests using irregular, gap-based silvicultural systems

Treesearch

John M. Lhotka; Michael R. Saunders; John M. Kabrick; Daniel C. Dey

2013-01-01

Throughout the Eastern United States, practitioners have primarily focused on using uniformly applied even-aged approaches to regenerate oak species. Irregular, gap-based silvicultural systems offer an alternative that retains continuous canopy cover, creates heterogeneous forest structure, and provides multiple income flows over a rotation. Although commonly used in...

The Impact of Politics in Local Education: Navigating White Water

ERIC Educational Resources Information Center

Owen, Jane C.

2006-01-01

Today, administrators must assume a different mindset if public schools are to remain viable and functional. Changing populations resulting in heterogeneous communities, the diversity of community values, and the finite resources available to meet the infinite desires of a demanding constituency have created the necessity for political acumen on…

Associations of grassland bird communities with black-tailed praire dogs in the North American Great Plains

USDA-ARS?s Scientific Manuscript database

Colonial, burrowing herbivores can serve as ecosystem engineers in grassland and shrubland ecosystems by creating belowground refugia, modifying vegetation structure and composition, serving as prey, and generating landscape heterogeneity. They can also serve a keystone species role by affecting the...

Complex Instruction: A Model for Reaching Up--and Out

ERIC Educational Resources Information Center

Tomlinson, Carol Ann

2018-01-01

Complex Instruction is a multifaceted instructional model designed to provide highly challenging learning opportunities for students in heterogeneous classrooms. The model provides a rationale for and philosophy of creating equity of access to excellent curriculum and instruction for a broad range of learners, guidance for preparing students for…

Harnessing Technology to Improve Formative Assessment of Student Conceptions in STEM: Forging a National Network

ERIC Educational Resources Information Center

Haudek, Kevin C.; Kaplan, Jennifer J.; Knight, Jennifer; Long, Tammy; Merrill, John; Munn, Alan; Nehm, Ross; Smith, Michelle; Urban-Lurain, Mark

2011-01-01

Concept inventories, consisting of multiple-choice questions designed around common student misconceptions, are designed to reveal student thinking. However, students often have complex, heterogeneous ideas about scientific concepts. Constructed-response assessments, in which students must create their own answer, may better reveal students'…

Experience(s) in Creating Distance Learning Texts

ERIC Educational Resources Information Center

Todd, Peter A.

2007-01-01

A combination of factors including longer working hours, emphasis on professional development, and increased access to the Internet have fuelled the current high demand for distance learning options in tertiary biology. Distance learner students come from a heterogeneous pool of ages, backgrounds and abilities and they require choice in how they…

Equity in the Classroom

ERIC Educational Resources Information Center

DiMartino, Joseph; Miles, Sherri

2004-01-01

In this article, the authors discuss three reform strategies designed to produce educational equity. The first strategy, heterogeneous grouping, does away with the controversial practice of placing students in different tracks based on their ability, which can polarize the student population into pro- and anti-school camps, create a "caste system"…

Food web heterogeneity and succession in created saltmarshes

USGS Publications Warehouse

Nordstrom, M C; Demopoulos, Amanda W.J.; Whitcraft, CR; Rismondo, A.; McMillan, P.; Gonzales, J P; Levin, L A

2015-01-01

1. Ecological restoration must achieve functional as well as structural recovery. Functional metrics for reestablishment of trophic interactions can be used to complement traditional monitoring of structural attributes. In addition, topographic effects on food web structure provide added information within a restoration context; often, created sites may require spatial heterogeneity to effectively match structure and function of natural habitats. 2. We addressed both of these issues in our study of successional development of benthic food web structure, with focus on bottom–up driven changes in macroinvertebrate consumer assemblages in the salt marshes of the Venice Lagoon, Italy. We combined quantified estimates of the changing community composition with stable isotope data (13C:12C and 15N:14N) to compare the general trophic structure between created (2–14 years) marshes and reference sites and along topographic elevation gradients within salt marshes. 3. Macrofaunal invertebrate consumers exhibited local, habitat-specific trophic patterns. Stable isotope-based trophic structure changed with increasing marsh age, in particular with regards to mid-elevation (Salicornia) habitats. In young marshes, the mid-elevation consumer signatures resembled those of unvegetated ponds. The mid elevation of older and natural marshes had a more distinct Salicornia-zone food web, occasionally resembling that of the highest (Sarcocornia-dominated) elevation. In summary, this indicates that primary producers and availability of vascular plant detritus structure consumer trophic interactions and the flow of carbon. 4. Functionally different consumers, subsurface-feeding detritivores (Oligochaeta) and surface grazers (Hydrobia sp.), showed distinct but converging trajectories of isotopic change over time, indicating that successional development may be asymmetric between ‘brown’ (detrital) guilds and ‘green’ (grazing) guilds in the food web. 5. Synthesis and applications. Created marsh food webs converged into a natural state over about a decade, with successional shifts seen in both consumer community composition and stable isotope space. Strong spatial effects were noted, highlighting the utility of stable isotopes to evaluate functional equivalence in spatially heterogeneous systems. Understanding the recovery of functional properties such as food web support, and their inherent spatial variability, is key to planning and managing successful habitat restoration.

Dynamic effective properties of heterogeneous geological formations with spherical inclusions under periodic time variations

NASA Astrophysics Data System (ADS)

Rabinovich, A.; Dagan, G.; Miloh, T.

2013-04-01

In unsteady groundwater flow (or similar processes of heat/electrical conduction), the heterogeneous medium structure is characterized by two random properties, the conductivity K and the specific storativity S. The average head field ⟨H ⟩and the associated effective properties Kef, Sef are determined for a layer with a periodic head drop between boundaries, such that H is periodic in time, and a medium made up of a matrix with a dilute concentration of spherical inclusions. In the common quasi-steady approximation, Kef is equal to the classical steady solution while Sef = SA, the arithmetic mean. We derive expressions for the frequency dependent Kef, Sef, which are generally complex, i.e., dynamic. The main result is the delineation of the ranges of the parameters: dimensionless frequency (ω) and contrasts of conductivity (κ) and storativity (s) between the matrix and the inclusions, for which dynamic effects are significant.

Morphological response to competition for light in the clonal Trifolium repens (Fabaceae).

PubMed

Bittebiere, Anne-Kristel; Renaud, Nolwenn; Clément, Bernard; Mony, Cendrine

2012-04-01

Plant communities in temperate zones are dominated by clonal plants that can plastically modify their growth characteristics in response to competition. Given that plants compete with one another, and the implications this has for species coexistence, we conducted a study to assess how clonal species morphologically respond to competition for light depending on its intensity and heterogeneity, which are determined by the competitor species. We assessed the morphological response to competition for light of the clonal species Trifolium repens L. by measuring its growth performance, and vertical and horizontal growth traits. We used five competitive environments, i.e., one without competitor and four differing by their competitor species creating different conditions of competition intensity and heterogeneity. The morphological response of Trifolium repens to competition for light depended on the competitor identity. Competition intensity and heterogeneity, determined by competitor identity, had an interactive effect on most traits. The increase in petiole elongation and specific leaf area due to increased competition intensity was observed only at low to intermediate competition heterogeneity. Competition heterogeneity promoted the elongation of clone connections allowing space exploration. Our results demonstrated that the intensity and heterogeneity of competition, which depended on competitor identity, are of primary importance in determining the plastic response of Trifolium repens. This emphasizes that it is important to consider the fine-scale spatial distribution of individuals when studying their interactions within plant communities.

Higher Education and the Public, Private and Non-Profit Sectors. Equal Partners in Promoting Regional Economic Development.

ERIC Educational Resources Information Center

Hughey, Aaron W.

2003-01-01

Advocates collaboration by universities with public, private, and nonprofit organizations to create value-added innovative economies in their regions. Discusses the advantages of such partnerships and various approaches to regional economic development. (Contains 29 references.) (SK)

Public and Private Interests in Networking Educational Services for Schools, Households, Communities.

ERIC Educational Resources Information Center

Sheekey, Arthur D.

1997-01-01

Discusses the networking of educational services for schools, homes, and communities. Highlights include equal access; the development of digital technologies; visions for electronic information services; the public sector; the private sector; creating learning communities; and future possibilities, including funding strategies. (LRW)

Trends and New Directions in Software Architecture

DTIC Science & Technology

2014-10-10

frameworks  Open source  Cloud strategies  NoSQL  Machine Learning  MDD  Incremental approaches  Dashboards  Distributed development...complexity grows  NoSQL Models are not created equal 2014 Our Current Research  Lightweight Evaluation and Architecture Prototyping for Big Data

Creation

NASA Astrophysics Data System (ADS)

Terry, Bruce

2003-04-01

An infinity of pure, non-moving space did not need to be created. What would or could replace it? The Self-Creating Universe* explains exactly the importance of why this infinity of space was static and how static space converted itself to first movement thus creating the two equal but opposite forces necessary for cosmic evolution to begin. This process provided the atmosphere for a self-causing third force to develope. The third force, in conjunction with the original two forces, became the background that triggered the creation of the physical forces. The derivatives of this action/re-action allowed all of the known cosmos to complete itself. All processes of movement constituting the cosmos, whether it be compression (creating density) or expansion (drawing a vacuum), must involve two or more of the three original forces. The full abstract of The Self-Creating Universe* theory, can be found at http://www.scuinc.com. *copyright by Bruce Terry All Rights Reserved

Numerical Simulation by using Soldiers Pile of the Embankment on Semarang-Solo Highway

NASA Astrophysics Data System (ADS)

Tumanduk, M. S. S. S.; Maki, T. S.; Pangkey, T. U. Y.; Pandeiroth, Y. C.

2018-02-01

Semarang-Solo highway works section II Gedawang-Penggaron constitutes a labile area. It is thought to be effect of the existence of coat clay shale which have moulded. For the purpose of anticipating the embankment mass movement it is placed line bored pile and stringed up (soldiers pile). The objective of this research is to know the efficient use of soldier’s pile of the embankment on Semarang-Solo highway section II Gedawang-Penggaron pursuant based upon numerical simulation. The result of analysis depicts that original slope in a stabil state with horizontal displacement which equal to 0.06 m and safety factor (SF) which equal to 1.31. The strengthened embankment with bored pile is not effective to give am SF improvement at slope so that, at this phase, the slope cannot be slid to be safe enough from landslide namely with horizontal displacement which equal to 0.20 m and SF which equal to 1.09. The effect of traffic load horizontal displacement is which equal to 0.21 m with SF which equal to 1.00. The earthquake simulation results horizontal displacement which equal to 0.75 m with SF which equal to 1.00. Long variation of bored pile of phase II by neglecting bored pile phase III at the depth 35 m yields horizontal displacement which equal to 0.03 m and SF optimum which equal to 2.17. The variation of pile location by placing bored pile under embankment slope foot with distance from the location of bored pile of phase II which equal to 20 m without changing the profile of the existing bored pile creates the horizontal displacement which equals to 0.02 m with SF which equal to 2.29. The result of the horizontal displacement and SF of the two alternative is safer compared to the existing condition (SF>1.5).

Ontology based heterogeneous materials database integration and semantic query

NASA Astrophysics Data System (ADS)

Zhao, Shuai; Qian, Quan

2017-10-01

Materials digital data, high throughput experiments and high throughput computations are regarded as three key pillars of materials genome initiatives. With the fast growth of materials data, the integration and sharing of data is very urgent, that has gradually become a hot topic of materials informatics. Due to the lack of semantic description, it is difficult to integrate data deeply in semantic level when adopting the conventional heterogeneous database integration approaches such as federal database or data warehouse. In this paper, a semantic integration method is proposed to create the semantic ontology by extracting the database schema semi-automatically. Other heterogeneous databases are integrated to the ontology by means of relational algebra and the rooted graph. Based on integrated ontology, semantic query can be done using SPARQL. During the experiments, two world famous First Principle Computational databases, OQMD and Materials Project are used as the integration targets, which show the availability and effectiveness of our method.

Dedicated heterogeneous node scheduling including backfill scheduling

DOEpatents

Wood, Robert R [Livermore, CA; Eckert, Philip D [Livermore, CA; Hommes, Gregg [Pleasanton, CA

2006-07-25

A method and system for job backfill scheduling dedicated heterogeneous nodes in a multi-node computing environment. Heterogeneous nodes are grouped into homogeneous node sub-pools. For each sub-pool, a free node schedule (FNS) is created so that the number of to chart the free nodes over time. For each prioritized job, using the FNS of sub-pools having nodes useable by a particular job, to determine the earliest time range (ETR) capable of running the job. Once determined for a particular job, scheduling the job to run in that ETR. If the ETR determined for a lower priority job (LPJ) has a start time earlier than a higher priority job (HPJ), then the LPJ is scheduled in that ETR if it would not disturb the anticipated start times of any HPJ previously scheduled for a future time. Thus, efficient utilization and throughput of such computing environments may be increased by utilizing resources otherwise remaining idle.

Effects of diffusion on total biomass in heterogeneous continuous and discrete-patch systems

USGS Publications Warehouse

DeAngelis, Donald L.; Ming Ni, Wei; Zhang, Bo

2016-01-01

Theoretical models of populations on a system of two connected patches previously have shown that when the two patches differ in maximum growth rate and carrying capacity, and in the limit of high diffusion, conditions exist for which the total population size at equilibrium exceeds that of the ideal free distribution, which predicts that the total population would equal the total carrying capacity of the two patches. However, this result has only been shown for the Pearl-Verhulst growth function on two patches and for a single-parameter growth function in continuous space. Here, we provide a general criterion for total population size to exceed total carrying capacity for three commonly used population growth rates for both heterogeneous continuous and multi-patch heterogeneous landscapes with high population diffusion. We show that a sufficient condition for this situation is that there is a convex positive relationship between the maximum growth rate and the parameter that, by itself or together with the maximum growth rate, determines the carrying capacity, as both vary across a spatial region. This relationship occurs in some biological populations, though not in others, so the result has ecological implications.

A new approach to tracer transport analysis: From fracture systems to strongly heterogeneous porous media

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

Tsang, Chin-Fu

Many current development and utilization of groundwater resources include a study of their flow and transport properties. These properties are needed in evaluating possible changes in groundwater quality and potential transport of hazardous solutes through the groundwater system. Investigation of transport properties of fractured rocks is an active area of research. Most of the current approaches to the study of flow and transport in fractured rocks cannot be easily used for analysis of tracer transport field data. A new approach is proposed based on a detailed study of transport through a fracture of variable aperture. This is a two-dimensional stronglymore » heterogeneous permeable system. It is suggested that tracer breakthrough curves can be analyzed based on an aperture or permeability probability distribution function that characterizes the tracer flow through the fracture. The results are extended to a multi-fracture system and can be equally applied to a strongly heterogeneous porous medium. Finally, the need for multi-point or line and areal tracer injection and observation tests is indicated as a way to avoid the sensitive dependence of point measurements on local permeability variability. 30 refs., 15 figs.« less

Diversity of devices along with diversity of data formats as a new challenge in global teaching and learning system

NASA Astrophysics Data System (ADS)

Sultana, Razia; Christ, Andreas; Meyrueis, Patrick

2014-07-01

The popularity of mobile communication devices is increasing day by day among students, especially for e-learning activities. "Always-ready-to-use" feature of mobile devices is a key motivation for students to use it even in a short break for a short time. This leads to new requirements regarding learning content presentation, user interfaces, and system architecture for heterogeneous devices. To support diverse devices is not enough to establish global teaching and learning system, it is equally important to support various formats of data along with different sort of devices having different capabilities in terms of processing power, display size, supported data formats, operating system, access method of data etc. Not only the existing data formats but also upcoming data formats, such as due to research results in the area of optics and photonics, virtual reality etc should be considered. This paper discusses the importance, risk and challenges of supporting heterogeneous devices to provide heterogeneous data as a learning content to make global teaching and learning system literally come true at anytime and anywhere. We proposed and implemented a sustainable architecture to support device and data format independent learning system.

Illusion optics via one-dimensional ultratransparent photonic crystals with shifted spatial dispersions.

PubMed

Yao, Zhongqi; Luo, Jie; Lai, Yun

2017-12-11

In this work, we propose that one-dimensional ultratransparent dielectric photonic crystals with wide-angle impedance matching and shifted elliptical equal frequency contours are promising candidate materials for illusion optics. The shift of the equal frequency contour does not affect the refractive behaviors, but enables a new degree of freedom in phase modulation. With such ultratransparent photonic crystals, we demonstrate some applications in illusion optics, including creating illusions of a different-sized scatterer and a shifted source with opposite phase. Such ultratransparent dielectric photonic crystals may establish a feasible platform for illusion optics devices at optical frequencies.

Diversity begets diversity: A global perspective on gender equality in scientific society leadership

PubMed Central

Burdfield-Steel, Emily; Potvin, Jacqueline M.; Heap, Stephen M.

2018-01-01

Research shows that gender inequality is still a major issue in academic science, yet academic societies may serve as underappreciated and effective avenues for promoting female leadership. That is, society membership is often self-selective, and board positions are elected (with a high turnover compared to institutions)—these characteristics, among others, may thus create an environment conducive to gender equality. We therefore investigate this potential using an information-theoretic approach to quantify gender equality (male:female ratios) in zoology society boards around the world. We compare alternative models to analyze how society characteristics might predict or correlate with the proportion of female leaders, and find that a cultural model, including society age, size of board and whether or not a society had an outward commitment or statement of equality, was the most informative predictor for the gender ratio of society boards and leadership positions. This model was more informative than alternatives that considered, for instance, geographic location, discipline of study or taxonomic focus. While women were more highly represented in society leadership than in institutional academic leadership, this representation was still far short of equal (~30%): we thus also provide a checklist and recommendations for societies to contribute to global gender equality in science. PMID:29847591

Diversity begets diversity: A global perspective on gender equality in scientific society leadership.

PubMed

Potvin, Dominique A; Burdfield-Steel, Emily; Potvin, Jacqueline M; Heap, Stephen M

2018-01-01

Research shows that gender inequality is still a major issue in academic science, yet academic societies may serve as underappreciated and effective avenues for promoting female leadership. That is, society membership is often self-selective, and board positions are elected (with a high turnover compared to institutions)-these characteristics, among others, may thus create an environment conducive to gender equality. We therefore investigate this potential using an information-theoretic approach to quantify gender equality (male:female ratios) in zoology society boards around the world. We compare alternative models to analyze how society characteristics might predict or correlate with the proportion of female leaders, and find that a cultural model, including society age, size of board and whether or not a society had an outward commitment or statement of equality, was the most informative predictor for the gender ratio of society boards and leadership positions. This model was more informative than alternatives that considered, for instance, geographic location, discipline of study or taxonomic focus. While women were more highly represented in society leadership than in institutional academic leadership, this representation was still far short of equal (~30%): we thus also provide a checklist and recommendations for societies to contribute to global gender equality in science.

Effects of Pre-Existing Target Structure on the Formation of Large Craters

NASA Technical Reports Server (NTRS)

Barnouin-Jha, O. S.; Cintala, M. J.; Crawford, D. A.

2003-01-01

The shapes of large-scale craters and the mechanics responsible for melt generation are influenced by broad and small-scale structures present in a target prior to impact. For example, well-developed systems of fractures often create craters that appear square in outline, good examples being Meteor Crater, AZ and the square craters of 433 Eros. Pre-broken target material also affects melt generation. Kieffer has shown how the shock wave generated in Coconino sandstone at Meteor crater created reverberations which, in combination with the natural target heterogeneity present, created peaks and troughs in pressure and compressed density as individual grains collided to produce a range of shock mineralogies and melts within neighboring samples. In this study, we further explore how pre-existing target structure influences various aspects of the cratering process. We combine experimental and numerical techniques to explore the connection between the scales of the impact generated shock wave and the pre-existing target structure. We focus on the propagation of shock waves in coarse, granular media, emphasizing its consequences on excavation, crater growth, ejecta production, cratering efficiency, melt generation, and crater shape. As a baseline, we present a first series of results for idealized targets where the particles are all identical in size and possess the same shock impedance. We will also present a few results, whereby we increase the complexities of the target properties by varying the grain size, strength, impedance and frictional properties. In addition, we investigate the origin and implications of reverberations that are created by the presence of physical and chemical heterogeneity in a target.

JUDGING PUBLIC RISK - NOT ALL ARSENICS ARE CREATED EQUAL

EPA Science Inventory

Many trace elements occur in the environment in several chemical forms, called species. Each species has unique physical-chemical properties that affect how it moves in the environment, as well as how available and toxic it is to humans and other animals. Hyphenated techniques, t...

Building Strong Community Partnerships: Equal Voice and Mutual Benefits

ERIC Educational Resources Information Center

Oberg De La Garza, Tammy; Moreno Kuri, Lissette

2014-01-01

This article explores an urban partnership and service-learning project deliberately created to improve literacy and strengthen learning communities in an urban, Latino neighborhood of Chicago. The project aligns activities and objectives with resources and needs of university participants, a Latino community organization, and local public…

RIVERINE ASSESSMENT USING MACROINVERTEBRATES: ALL METHODS ARE NOT CREATED EQUAL

EPA Science Inventory

In 1999, we compared six benthic macroinvertebrate field sampling methods for nonwadeable streams based on those developed for three major programs (EMAP-SW, NAWQA, and Ohio EPA), at each of sixty sites across four tributaries to the Ohio River. Water chemistry samples and physi...

Television & Literacy Development in the Czech Republic. Chapter 14.

ERIC Educational Resources Information Center

Hubik, Stanislav

This chapter begins by explaining that cultural literacy is the ability of a community to create relationships, processes, and institutions aimed at multifaceted community development using indigenous resources (natural, human, social, and cultural). Literacy development in a rural community involves three equally important dimensions--social,…

Physical Heterogeneity Increases Biofilm Resource Use and Its Molecular Diversity in Stream Mesocosms

PubMed Central

Singer, Gabriel; Besemer, Katharina; Schmitt-Kopplin, Philippe; Hödl, Iris; Battin, Tom J.

2010-01-01

Background Evidence increasingly shows that stream ecosystems greatly contribute to global carbon fluxes. This involves a tight coupling between biofilms, the dominant form of microbial life in streams, and dissolved organic carbon (DOC), a very significant pool of organic carbon on Earth. Yet, the interactions between microbial biodiversity and the molecular diversity of resource use are poorly understood. Methodology/Principal Findings Using six 40-m-long streamside flumes, we created a gradient of streambed landscapes with increasing spatial flow heterogeneity to assess how physical heterogeneity, inherent to streams, affects biofilm diversity and DOC use. We determined bacterial biodiversity in all six landscapes using 16S-rRNA fingerprinting and measured carbon uptake from glucose and DOC experimentally injected to all six flumes. The diversity of DOC molecules removed from the water was determined from ultrahigh-resolution Fourier Transform Ion Cyclotron Resonance mass spectrometry (FTICR-MS). Bacterial beta diversity, glucose and DOC uptake, and the molecular diversity of DOC use all increased with increasing flow heterogeneity. Causal modeling and path analyses of the experimental data revealed that the uptake of glucose was largely driven by physical processes related to flow heterogeneity, whereas biodiversity effects, such as complementarity, most likely contributed to the enhanced uptake of putatively recalcitrant DOC compounds in the streambeds with higher flow heterogeneity. Conclusions/Significance Our results suggest biophysical mechanisms, including hydrodynamics and microbial complementarity effects, through which physical heterogeneity induces changes of resource use and carbon fluxes in streams. These findings highlight the importance of fine-scale streambed heterogeneity for microbial biodiversity and ecosystem functioning in streams, where homogenization and loss of habitats increasingly reduce biodiversity. PMID:20376323

Dispersion Analysis Using Particle Tracking Simulations Through Heterogeneity Based on Outcrop Lidar Imagery

NASA Astrophysics Data System (ADS)

Klise, K. A.; Weissmann, G. S.; McKenna, S. A.; Tidwell, V. C.; Frechette, J. D.; Wawrzyniec, T. F.

2007-12-01

Solute plumes are believed to disperse in a non-Fickian manner due to small-scale heterogeneity and variable velocities that create preferential pathways. In order to accurately predict dispersion in naturally complex geologic media, the connection between heterogeneity and dispersion must be better understood. Since aquifer properties can not be measured at every location, it is common to simulate small-scale heterogeneity with random field generators based on a two-point covariance (e.g., through use of sequential simulation algorithms). While these random fields can produce preferential flow pathways, it is unknown how well the results simulate solute dispersion through natural heterogeneous media. To evaluate the influence that complex heterogeneity has on dispersion, we utilize high-resolution terrestrial lidar to identify and model lithofacies from outcrop for application in particle tracking solute transport simulations using RWHet. The lidar scan data are used to produce a lab (meter) scale two-dimensional model that captures 2-8 mm scale natural heterogeneity. Numerical simulations utilize various methods to populate the outcrop structure captured by the lidar-based image with reasonable hydraulic conductivity values. The particle tracking simulations result in residence time distributions used to evaluate the nature of dispersion through complex media. Particle tracking simulations through conductivity fields produced from the lidar images are then compared to particle tracking simulations through hydraulic conductivity fields produced from sequential simulation algorithms. Based on this comparison, the study aims to quantify the difference in dispersion when using realistic and simplified representations of aquifer heterogeneity. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Biotic Drivers of Spatial Heterogeneity and Implications for River Ecosystems

NASA Astrophysics Data System (ADS)

Wohl, Ellen

2017-04-01

Rivers throughout the northern hemisphere have been simplified and homogenized by the removal of beavers and instream wood, along with numerous forms of channel engineering and flow regulation. Loss of spatial heterogeneity in river corridors - channels and floodplains - affects downstream fluxes of water, sediment, organic matter, and nutrients, as well as stream metabolism, biomass, and biodiversity. Recent work in streams of the Colorado Rocky Mountains illustrates how the presence of beavers and instream wood can facilitate spatial heterogeneity by creating stable, persistent, multithread channel planform and high channel-floodplain and channel-hyporheic zone connectivity. This spatial heterogeneity facilitates retention of water in pools, floodplain wetlands, and hyporheic storage. Suspended sediment, particulate organic matter (POM), and solutes are also more likely to be retained in these stream segments than in more uniform stream segments with greater downstream conveyance. Retention of POM and solutes equates to greater volumes of organic carbon storage per unit valley length and greater rates of nitrogen uptake. Spatially heterogeneous stream segments also exhibit greater biomass and biodiversity of aquatic macroinvertebrates, salmonid fish, and riparian spiders than do more uniform stream segments. These significant differences in stream form and function are unlikely to be unique to this field area and can provide a conceptual model for understanding and restoring ecosystem functions in other rivers.

Physical Heterogeneity and Aquatic Community Function in ...

EPA Pesticide Factsheets

The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological components is a central tenet for the interdisciplinary field of river science. Relationships between the physical heterogeneity and food web character of functional process zones (FPZs) – large tracts of river with a similar geomorphic character - in the Kanawha River (West Virginia, USA) are examined in this study. Food web character was measured as food chain length (FCL), which reflects ecological community structure and ecosystem function. Our results show the same basal resources were present throughout the Kanawha River but their assimilation into the aquatic food web by primary consumers differed between FPZs. Differences in the trophic position of secondary consumers – fish - were also recorded between FPZs. Overall, both the morphological heterogeneity and heterogeneity of the river bed sediment of FPZs were significantly correlated with FCL. Specifically, FCL increases with greater FPZ physical heterogeneity, supporting tenet 8 of the river ecosystem synthesis. In previous research efforts, we delineated the functional process zones (FPZs) of the Kanawha River. In this study, we examined the relationship between the hydrogeomorphically-derived zones with food webs.

Design and fabrication of a realistic anthropomorphic heterogeneous head phantom for MR purposes

PubMed Central

Wood, Sossena; Krishnamurthy, Narayanan; Santini, Tales; Raval, Shailesh; Farhat, Nadim; Holmes, John Andy; Ibrahim, Tamer S.

2017-01-01

Objective The purpose of this study is to design an anthropomorphic heterogeneous head phantom that can be used for MRI and other electromagnetic applications. Materials and methods An eight compartment, physical anthropomorphic head phantom was developed from a 3T MRI dataset of a healthy male. The designed phantom was successfully built and preliminarily evaluated through an application that involves electromagnetic-tissue interactions: MRI (due to it being an available resource). The developed phantom was filled with media possessing electromagnetic constitutive parameters that correspond to biological tissues at ~297 MHz. A preliminary comparison between an in-vivo human volunteer (based on whom the anthropomorphic head phantom was created) and various phantoms types, one being the anthropomorphic heterogeneous head phantom, were performed using a 7 Tesla human MRI scanner. Results Echo planar imaging was performed and minimal ghosting and fluctuations were observed using the proposed anthropomorphic phantom. The magnetic field distributions (during MRI experiments at 7 Tesla) and the scattering parameter (measured using a network analyzer) were most comparable between the anthropomorphic heterogeneous head phantom and an in-vivo human volunteer. Conclusion The developed anthropomorphic heterogeneous head phantom can be used as a resource to various researchers in applications that involve electromagnetic-biological tissue interactions such as MRI. PMID:28806768

Analysis of image heterogeneity using 2D Minkowski functionals detects tumor responses to treatment.

PubMed

Larkin, Timothy J; Canuto, Holly C; Kettunen, Mikko I; Booth, Thomas C; Hu, De-En; Krishnan, Anant S; Bohndiek, Sarah E; Neves, André A; McLachlan, Charles; Hobson, Michael P; Brindle, Kevin M

2014-01-01

The acquisition of ever increasing volumes of high resolution magnetic resonance imaging (MRI) data has created an urgent need to develop automated and objective image analysis algorithms that can assist in determining tumor margins, diagnosing tumor stage, and detecting treatment response. We have shown previously that Minkowski functionals, which are precise morphological and structural descriptors of image heterogeneity, can be used to enhance the detection, in T1 -weighted images, of a targeted Gd(3+) -chelate-based contrast agent for detecting tumor cell death. We have used Minkowski functionals here to characterize heterogeneity in T2 -weighted images acquired before and after drug treatment, and obtained without contrast agent administration. We show that Minkowski functionals can be used to characterize the changes in image heterogeneity that accompany treatment of tumors with a vascular disrupting agent, combretastatin A4-phosphate, and with a cytotoxic drug, etoposide. Parameterizing changes in the heterogeneity of T2 -weighted images can be used to detect early responses of tumors to drug treatment, even when there is no change in tumor size. The approach provides a quantitative and therefore objective assessment of treatment response that could be used with other types of MR image and also with other imaging modalities. Copyright © 2013 Wiley Periodicals, Inc.

Innovative approach for the in vitro research on biomedical scaffolds designed and customized with CAD-CAM technology.

PubMed

Marrelli, Massimo; Pujia, Antonella; Palmieri, Francesca; Gatto, Roberto; Falisi, Giovanni; Gargari, Marco; Caruso, Silvia; Apicella, Davide; Rastelli, Claudio; Nardi, Gianna Maria; Paduano, Francesco; Tatullo, Marco

2016-12-01

Studies on biomaterials involve assays aimed to assess the interactions between the biomaterial and the cells seeded on its surface. However, the morphology of biomaterials is heterogeneous and it could be tricky to standardize the results among different biomaterials and the classic plastic plates. In this light, we decided to create, by means of computer-aided design (CAD) technology, a standardized sample model, with equal shape and sizes, able to fit into a classic shape of a 96-wells tissue culture plate (TCP). The design of this sample consists of a hole in the top in order to allow the injected cells to settle without them being able to slip from the sides of the sample to the bottom of the TCP wells. This CAD project is made using the software Pro-Engineer. The sample will totally fill the wells of the 96-well TCP. Dental pulp stem cells have been used to assess the ability of the different sample to support and promote the cell proliferation. Twelve titanium, 12 gold-palladium, and 12 zirconium oxide customized samples were designed by means of the software cam powermill, by importing the .stl file created in Pro-Engineer software. The proliferation rate of the tested scaffolds showed to be similar to the control in the group with the customized shape. We think that our method can be useful to test different types of scaffolds when a greater accuracy of the measurements is desirable in order to verify the cell behavior of these scaffolds. Our innovative method can improve the standardization process in the evaluation of cell behavior on different biomaterials to open the way to more reliable tests on biomatrices functionalized with drugs or growth factors applied to the future regenerative medicine. © The Author(s) 2016.

Cellular manipulation and patterning using ferromagnetic nanowires

NASA Astrophysics Data System (ADS)

Hultgren, Anne

Ferromagnetic nanowires are demonstrated as an effective tool to apply forces to living cells. Both magnetic cell separations and the magnetic patterning of cells on a substrate will be accomplished through the use of cell-nanowire interactions as well as nanowire-magnetic field interactions. When introduced into cultures of NIH-3T3 cells, the nanowires are internalized by cells via the integrin-mediated adhesion pathway without inflicting any toxic effects on the cell cycle over the course of several days. In addition, the length of the nanowires was found to have an effect on the cell-nanowire interactions when the cells were dissociated from the tissue culture dish. To compare the effectiveness of the nanowires as a means of manipulating cells to the current technology which is based on superparamagnetic beads, magnetic cell separations were performed with electrodeposited Ni nanowires 350 nm in diameter and 5--35 mum long in field gradients of 80 T/m. Single-pass separations of NIH-3T3 cells bound to nanowires achieve up to 81% purity with 85% yield, a dramatic improvement over the 55% purity and 20% yield obtained with the beads. The yield for the separations were found to be dependent on the length of the nanowires, and was maximized when the length of the nanowires equaled the diameter of the cells. This dependence was exploited to perform a size-selective magnetic separation. Substrates containing arrays of micro-magnets, fabricated using photolithography, were placed in cell cultures. These micro-magnet arrays create regions of locally strong magnetic field gradients to trap nanowires in specific locations on the substrate. These substrates were used in conjunction with fluid flow and a weak, externally applied magnetic field to create and control patterns of cells bound to nanowires. Controlled isolation of heterogeneous pairs and groups of cells will enable the study of the biochemistry of cell-cell contacts.

CAVEman: Standardized Anatomical Context for Biomedical Data Mapping

ERIC Educational Resources Information Center

Turinsky, Andrei L.; Fanea, Elena; Trinh, Quang; Wat, Stephen; Hallgrimsson, Benedikt; Dong, Xiaoli; Shu, Xueling; Stromer, Julie N.; Hill, Jonathan W.; Edwards, Carol; Grosenick, Brenda; Yajima, Masumi; Sensen, Christoph W.

2008-01-01

The authors have created a software system called the CAVEman, for the visual integration and exploration of heterogeneous anatomical and biomedical data. The CAVEman can be applied for both education and research tasks. The main component of the system is a three-dimensional digital atlas of the adult male human anatomy, structured according to…

Determination of smoke plume and layer heights using scanning lidar data

Treesearch

Vladimir A. Kovalev; Alexander Petkov; Cyle Wold; Shawn Urbanski; Wei Min Hao

2009-01-01

The methodology of using mobile scanning lidar data for investigation of smoke plume rise and high-resolution smoke dispersion is considered. The methodology is based on the lidar-signal transformation proposed recently [Appl. Opt. 48, 2559 (2009)]. In this study, similar methodology is used to create the atmospheric heterogeneity height indicator (HHI...

Application of ground-based LIDAR for fine-scale forest fuel modeling

Treesearch

E. Louise Loudermilk; Abhinav Singhania; Juan C. Fernandez; J. Kevin Hiers; Joseph J. O' Brien; Wendell P. Cropper Jr.; K. Clint Slatton; Robert J. Mitchell

2007-01-01

Frequent (1 to 5 year) low intensity fire regimes of longleaf pine (Pinus palustris) savannas of the Southeastern United States create a continuous fuelbed of understory grasses, forbs, flammable pine needle litter, with interstitial hardwood shrubs. Measuring the spatial heterogeneity of these fine-fuels can be difficult, requiring intensive field...

Case for a field-programmable gate array multicore hybrid machine for an image-processing application

NASA Astrophysics Data System (ADS)

Rakvic, Ryan N.; Ives, Robert W.; Lira, Javier; Molina, Carlos

2011-01-01

General purpose computer designers have recently begun adding cores to their processors in order to increase performance. For example, Intel has adopted a homogeneous quad-core processor as a base for general purpose computing. PlayStation3 (PS3) game consoles contain a multicore heterogeneous processor known as the Cell, which is designed to perform complex image processing algorithms at a high level. Can modern image-processing algorithms utilize these additional cores? On the other hand, modern advancements in configurable hardware, most notably field-programmable gate arrays (FPGAs) have created an interesting question for general purpose computer designers. Is there a reason to combine FPGAs with multicore processors to create an FPGA multicore hybrid general purpose computer? Iris matching, a repeatedly executed portion of a modern iris-recognition algorithm, is parallelized on an Intel-based homogeneous multicore Xeon system, a heterogeneous multicore Cell system, and an FPGA multicore hybrid system. Surprisingly, the cheaper PS3 slightly outperforms the Intel-based multicore on a core-for-core basis. However, both multicore systems are beaten by the FPGA multicore hybrid system by >50%.

Effects of oxidation on surface heterogeneity of carbosils

NASA Astrophysics Data System (ADS)

Charmas, B.; Leboda, R.; Gérard, G.; Villiéras, F.

2002-08-01

Carbon-silica adsorbents (carbosils), prepared by pyrolysis of methylene chloride (CH 2Cl 2) on the surface of a porous silica gel, were subjected to an oxidizing hydrothermal treatment (HTT) at 200 °C, using a hydrogen peroxide water solution as a modification medium. Conventional nitrogen adsorption volumetry and low-pressure argon and nitrogen adsorption techniques were used to analyze and compare textural properties and surface heterogeneity of initial and hydrothermally treated samples. In the presence of carbon, the mesoporous network of silica gel is protected from the massive collapse generally observed after oxidizing HTT. For carbosils, some changes occur during HTT, leading to a slight decrease of specific surface areas accompanied by an increase in mean mesopore size. The argon and nitrogen condensation energy distributions, derived from low-pressure adsorption experiments, indicate that both silica and pyrocarbon materials were modified during HTT. Depolymerization and recondensation processes occur for silica, creating new silica surfaces. These processes are responsible of the decrease in specific surface areas. For pyrocarbon, similar depolymerization and recondensation processes probably occur, creating new and high-energy surface sites.

Perfect harmony: A mathematical analysis of four historical tunings

NASA Astrophysics Data System (ADS)

Page, Michael F.

2004-10-01

In Western music, a musical interval defined by the frequency ratio of two notes is generally considered consonant when the ratio is composed of small integers. Perfect harmony or an ``ideal just scale,'' which has no exact solution, would require the division of an octave into 12 notes, each of which would be used to create six other consonant intervals. The purpose of this study is to analyze four well-known historical tunings to evaluate how well each one approximates perfect harmony. The analysis consists of a general evaluation in which all consonant intervals are given equal weighting and a specific evaluation for three preludes from Bach's ``Well-Tempered Clavier,'' for which intervals are weighted in proportion to the duration of their occurrence. The four tunings, 5-limit just intonation, quarter-comma meantone temperament, well temperament (Werckmeister III), and equal temperament, are evaluated by measures of centrality, dispersion, distance, and dissonance. When all keys and consonant intervals are equally weighted, equal temperament demonstrates the strongest performance across a variety of measures, although it is not always the best tuning. Given C as the starting note for each tuning, equal temperament and well temperament perform strongly for the three ``Well-Tempered Clavier'' preludes examined. .

Building IoT Services for Aging in Place Using Standard-Based IoT Platforms and Heterogeneous IoT Products.

PubMed

Fattah, Sheik Mohammad Mostakim; Sung, Nak-Myoung; Ahn, Il-Yeup; Ryu, Minwoo; Yun, Jaeseok

2017-10-11

An aging population and human longevity is a global trend. Many developed countries are struggling with the yearly increasing healthcare cost that dominantly affects their economy. At the same time, people living with old adults suffering from a progressive brain disorder such as Alzheimer's disease are enduring even more stress and depression than those patients while caring for them. Accordingly, seniors' ability to live independently and comfortably in their current home for as long as possible has been crucial to reduce the societal cost for caregiving and thus give family members peace of mind, called 'aging in place' (AIP). In this paper we present a way of building AIP services using standard-based IoT platforms and heterogeneous IoT products. An AIP service platform is designed and created by combining previous standard-based IoT platforms in a collaborative way. A service composition tool is also created that allows people to create AIP services in an efficient way. To show practical usability of our proposed system, we choose a service scenario for medication compliance and implement a prototype service which could give old adults medication reminder appropriately at the right time (i.e., when it is time to need to take pills) through light and speaker at home but also wrist band and smartphone even outside the home.

Building IoT Services for Aging in Place Using Standard-Based IoT Platforms and Heterogeneous IoT Products

PubMed Central

Fattah, Sheik Mohammad Mostakim; Sung, Nak-Myoung; Ahn, Il-Yeup; Ryu, Minwoo; Yun, Jaeseok

2017-01-01

An aging population and human longevity is a global trend. Many developed countries are struggling with the yearly increasing healthcare cost that dominantly affects their economy. At the same time, people living with old adults suffering from a progressive brain disorder such as Alzheimer’s disease are enduring even more stress and depression than those patients while caring for them. Accordingly, seniors’ ability to live independently and comfortably in their current home for as long as possible has been crucial to reduce the societal cost for caregiving and thus give family members peace of mind, called ‘aging in place’ (AIP). In this paper we present a way of building AIP services using standard-based IoT platforms and heterogeneous IoT products. An AIP service platform is designed and created by combining previous standard-based IoT platforms in a collaborative way. A service composition tool is also created that allows people to create AIP services in an efficient way. To show practical usability of our proposed system, we choose a service scenario for medication compliance and implement a prototype service which could give old adults medication reminder appropriately at the right time (i.e., when it is time to need to take pills) through light and speaker at home but also wrist band and smartphone even outside the home. PMID:29019964

Beyond CMOS: heterogeneous integration of III–V devices, RF MEMS and other dissimilar materials/devices with Si CMOS to create intelligent microsystems

PubMed Central

Kazior, Thomas E.

2014-01-01

Advances in silicon technology continue to revolutionize micro-/nano-electronics. However, Si cannot do everything, and devices/components based on other materials systems are required. What is the best way to integrate these dissimilar materials and to enhance the capabilities of Si, thereby continuing the micro-/nano-electronics revolution? In this paper, I review different approaches to heterogeneously integrate dissimilar materials with Si complementary metal oxide semiconductor (CMOS) technology. In particular, I summarize results on the successful integration of III–V electronic devices (InP heterojunction bipolar transistors (HBTs) and GaN high-electron-mobility transistors (HEMTs)) with Si CMOS on a common silicon-based wafer using an integration/fabrication process similar to a SiGe BiCMOS process (BiCMOS integrates bipolar junction and CMOS transistors). Our III–V BiCMOS process has been scaled to 200 mm diameter wafers for integration with scaled CMOS and used to fabricate radio-frequency (RF) and mixed signals circuits with on-chip digital control/calibration. I also show that RF microelectromechanical systems (MEMS) can be integrated onto this platform to create tunable or reconfigurable circuits. Thus, heterogeneous integration of III–V devices, MEMS and other dissimilar materials with Si CMOS enables a new class of high-performance integrated circuits that enhance the capabilities of existing systems, enable new circuit architectures and facilitate the continued proliferation of low-cost micro-/nano-electronics for a wide range of applications. PMID:24567473

Beyond CMOS: heterogeneous integration of III-V devices, RF MEMS and other dissimilar materials/devices with Si CMOS to create intelligent microsystems.

PubMed

Kazior, Thomas E

2014-03-28

Advances in silicon technology continue to revolutionize micro-/nano-electronics. However, Si cannot do everything, and devices/components based on other materials systems are required. What is the best way to integrate these dissimilar materials and to enhance the capabilities of Si, thereby continuing the micro-/nano-electronics revolution? In this paper, I review different approaches to heterogeneously integrate dissimilar materials with Si complementary metal oxide semiconductor (CMOS) technology. In particular, I summarize results on the successful integration of III-V electronic devices (InP heterojunction bipolar transistors (HBTs) and GaN high-electron-mobility transistors (HEMTs)) with Si CMOS on a common silicon-based wafer using an integration/fabrication process similar to a SiGe BiCMOS process (BiCMOS integrates bipolar junction and CMOS transistors). Our III-V BiCMOS process has been scaled to 200 mm diameter wafers for integration with scaled CMOS and used to fabricate radio-frequency (RF) and mixed signals circuits with on-chip digital control/calibration. I also show that RF microelectromechanical systems (MEMS) can be integrated onto this platform to create tunable or reconfigurable circuits. Thus, heterogeneous integration of III-V devices, MEMS and other dissimilar materials with Si CMOS enables a new class of high-performance integrated circuits that enhance the capabilities of existing systems, enable new circuit architectures and facilitate the continued proliferation of low-cost micro-/nano-electronics for a wide range of applications.

Velocity profile development for a poultry facility acid scrubber

USDA-ARS?s Scientific Manuscript database

Determination of the air velocity profile for 12 experimental configurations (ECs) of an acid scrubber was carried out using an equal area traverse method with a vane axial anemometer. Four velocity profile plots were created for each configuration to determine the four optimal ECs. ECs were selecte...

Contesting Global Neoliberalism and Creating Alternative Futures

ERIC Educational Resources Information Center

Hursh, David W.; Henderson, Joseph A.

2011-01-01

Neoliberal policies, in spite of their considerable damage to economic equality, the environment, and education, remain dominant. In this paper, we suggest that neoliberalism has remained dominant in part because the power elite who benefit from the policies have gained control over both public debate and policy-making. By dominating the discourse…

Gender Intelligence.

ERIC Educational Resources Information Center

Zemsky, Robert, Ed.

2001-01-01

This essay explores the questions that women faculty in institutions of all kinds have been pondering. What would be the attributes of a higher education system that provides opportunities for growth and advancement to women that are equal to those provided for men? What aspects of academic culture would have to change to create a more equitable…

Not All Female-Headed Families Are Created Equal.

ERIC Educational Resources Information Center

Besharov, Douglas J.; Quin, Alison J.

1987-01-01

Changes in parenting behavior have led to the troubling situation called the "feminization of poverty." Families headed by divorced women are doing better than is commonly supposed. Families headed by never-married women are doing worse. Public policy should reflect the differing needs of these two groups. (VM)

Compilation of Action Research Papers in English Education.

ERIC Educational Resources Information Center

Sherman, Thomas F.; Lundquist, Margaret

This action research compilation contains two research projects: "Increasing Student Appreciation of Poetry through the Use of Contemporary Music" by Paul G. Senjem and "Are Men and Women Created Equal? Gender in the Classroom" by Jennifer Joyce Plitzuweit. The researcher/author of the first paper states that his goal was to…

Landscape assessment for tourism

Treesearch

Clare A. Gunn

1979-01-01

Increased development of landscapes for tourism now creates problems of integrating the many parts. Accomplishments at the site scale have not been matched with equal progress at the regional scale. This concept, and its example of application, shows promise of assisting regions in assessing their potential of landscapes before development. With such a concept, not...

Children's Literature as a Pathway of Possibilities

ERIC Educational Resources Information Center

Wilkins, Ebony Joy

2014-01-01

Visionaries like W. E. B. Du Bois opened the door to possibility and opportunity for the next generations of African American artists. Among those who benefited from and contributed to this legacy are award-winning African American authors and illustrators who created works that celebrate Black children, equality, and diversity. These artists…

Equalizing Educational Opportunity: In Defense of Bilingual Education--A California Perspective

ERIC Educational Resources Information Center

Wang, Hao

2016-01-01

Under critical examination, the English language and its use in daily interactions carry with them symbolic values in our social world, including social mobility, educational achievement, and employment. Its representations in government bodies, mass media, education, and legal documents have further increased those values and subtly created a…

Should Institutions Expand the Academic Record?

ERIC Educational Resources Information Center

Book, Connie; Parks, Rodney

2016-01-01

Higher education is more competitive than ever before. New terms for curricular gains--for example badges and competencies are becoming the norm. Not all student experiences are created equal. In the "curriculum of experience," Elon University has advanced and deepened a 20-year-old general education requirement that students complete…

Who Benefits from the Massification of Higher Education in Taiwan?

ERIC Educational Resources Information Center

Prudence, Chou Chuing; Li-Tien, Wang

2012-01-01

The objectives of expanding higher education are to foster advanced personnel and realize the concept of achieving equal access to education. The problems created by the expansion of higher education in many countries, including Taiwan, in fact indicate a divergence from originally anticipated objectives. Such problems include the uneven…

78 FR 62339 - Blind Americans Equality Day, 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-18

... innovation in business and government, or creating powerful music and art, blind and visually impaired... more level playing field and ensure students with disabilities have access to the general education... commitment to using Braille to open doors for students who are blind or visually impaired, so every student...

Civil Rights Commission Reports on Discrimination

ERIC Educational Resources Information Center

Linguistic Reporter, 1974

1974-01-01

The U.S. Commission on Civil Rights maintained in a report that Mexican American students are experiencing widespread discrimination in public schools in the Southwest and made 51 recommendations to help promote equal education for Mexican Americans. It is claimed that language and cultural bias has created discriminatory practices. (SW)

Working with Advocates

ERIC Educational Resources Information Center

Doan, Kim

2010-01-01

Court appointed special advocates (CASAs) are volunteers who represent abused and neglected children in the court system. David Soukup, a judge in Washington State, created the first CASA program in 1977 to gather more information about the children whose cases were appearing before him. The likelihood of meeting a CASA may be equal to the…

Becoming Better Parents. Fourth Edition.

ERIC Educational Resources Information Center

Balson, Maurice

In response to new problems facing parents and families, this book provides democratic parenting strategies that diverge from traditional autocratic methods and reflect the values of respect, shared responsibility, self-discipline, and social equality. The goal of the book is to create a new tradition in child raising that will help to foster the…

Are All Homeschooling Methods Created Equal?

ERIC Educational Resources Information Center

Taylor-Hough, Deborah

2010-01-01

For parents looking to see their children develop into the self-reliant, critical thinkers John Taylor Gatto described in his essay, "Against School," and other works, a combination of unschooling and the Charlotte Mason method would have the best chance of overall success. Research shows any method of homeschooling produces standardized test…

Eleven Ways to Stamp Out the Potential for Sexual Harassment.

ERIC Educational Resources Information Center

Decker, Robert H.

1988-01-01

Reviews the 1980 Equal Employment Opportunity Commission guidelines defining sexual harassment as a form of sex discrimination. Advises 11 steps, including creating clear-cut policies and guidelines to help school officials deal with the problem. Insets offer policy "pointers" and several recommendations for staff members desiring to counter…

Are All Infinities Created Equal?

ERIC Educational Resources Information Center

Paoletti, Teo J.

2013-01-01

Can one infinity be more than another infinity? Ask students this question, and many will be puzzled; others will insist that "infinity is infinity." The question seems to pique their interest and provides an opportunity to present the beautifully simple but counterintuitive proofs concerning the size of infinity first constructed by…

77 FR 75105 - Advisory Committee on Beginning Farmers and Ranchers; Intent To Renew and Request for Nominations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-19

..., policies, and programs that will enhance opportunities and create new farming and ranching operations. The... farming producers (industry), related government, State, and Tribal agricultural agencies, academic... 1041-001. Equal opportunity practices, in line with the USDA policies, will be followed in all...

Astronomy and Creationism.

ERIC Educational Resources Information Center

Morrison, David

1982-01-01

Discusses the effects on astronomy courses/curriculum if equal time were given to the concept that the universe was created in its present form about ten thousand years ago. Includes the full text on a resolution concerning creationism passed by the Board of Directors of the Astronomical Society of the Pacific. (Author/JN)

Admissions Testing & Institutional Admissions Processes

ERIC Educational Resources Information Center

Hossler, Don; Kalsbeek, David

2009-01-01

The array of admissions models and the underlying, and sometimes conflicting goals people have for college admissions, create the dynamics and the tensions that define the contemporary context for enrollment management. The senior enrollment officer must ask, for example, how does an institution try to assure transparency, equality of access,…

How Obstacles Perturb Population Fronts and Alter Their Genetic Structure.

PubMed

Möbius, Wolfram; Murray, Andrew W; Nelson, David R

2015-12-01

As populations spread into new territory, environmental heterogeneities can shape the population front and genetic composition. We focus here on the effects of an important building block of heterogeneous environments, isolated obstacles. With a combination of experiments, theory, and simulation, we show how isolated obstacles both create long-lived distortions of the front shape and amplify the effect of genetic drift. A system of bacteriophage T7 spreading on a spatially heterogeneous Escherichia coli lawn serves as an experimental model system to study population expansions. Using an inkjet printer, we create well-defined replicates of the lawn and quantitatively study the population expansion of phage T7. The transient perturbations of the population front found in the experiments are well described by a model in which the front moves with constant speed. Independent of the precise details of the expansion, we show that obstacles create a kink in the front that persists over large distances and is insensitive to the details of the obstacle's shape. The small deviations between experimental findings and the predictions of the constant speed model can be understood with a more general reaction-diffusion model, which reduces to the constant speed model when the obstacle size is large compared to the front width. Using this framework, we demonstrate that frontier genotypes just grazing the side of an isolated obstacle increase in abundance, a phenomenon we call 'geometry-enhanced genetic drift', complementary to the founder effect associated with spatial bottlenecks. Bacterial range expansions around nutrient-poor barriers and stochastic simulations confirm this prediction. The effect of the obstacle on the genealogy of individuals at the front is characterized by simulations and rationalized using the constant speed model. Lastly, we consider the effect of two obstacles on front shape and genetic composition of the population illuminating the effects expected from complex environments with many obstacles.

How Obstacles Perturb Population Fronts and Alter Their Genetic Structure

PubMed Central

Möbius, Wolfram; Murray, Andrew W.; Nelson, David R.

2015-01-01

As populations spread into new territory, environmental heterogeneities can shape the population front and genetic composition. We focus here on the effects of an important building block of heterogeneous environments, isolated obstacles. With a combination of experiments, theory, and simulation, we show how isolated obstacles both create long-lived distortions of the front shape and amplify the effect of genetic drift. A system of bacteriophage T7 spreading on a spatially heterogeneous Escherichia coli lawn serves as an experimental model system to study population expansions. Using an inkjet printer, we create well-defined replicates of the lawn and quantitatively study the population expansion of phage T7. The transient perturbations of the population front found in the experiments are well described by a model in which the front moves with constant speed. Independent of the precise details of the expansion, we show that obstacles create a kink in the front that persists over large distances and is insensitive to the details of the obstacle’s shape. The small deviations between experimental findings and the predictions of the constant speed model can be understood with a more general reaction-diffusion model, which reduces to the constant speed model when the obstacle size is large compared to the front width. Using this framework, we demonstrate that frontier genotypes just grazing the side of an isolated obstacle increase in abundance, a phenomenon we call ‘geometry-enhanced genetic drift’, complementary to the founder effect associated with spatial bottlenecks. Bacterial range expansions around nutrient-poor barriers and stochastic simulations confirm this prediction. The effect of the obstacle on the genealogy of individuals at the front is characterized by simulations and rationalized using the constant speed model. Lastly, we consider the effect of two obstacles on front shape and genetic composition of the population illuminating the effects expected from complex environments with many obstacles. PMID:26696601

Link-quality measurement and reporting in wireless sensor networks.

PubMed

Chehri, Abdellah; Jeon, Gwanggil; Choi, Byoungjo

2013-03-04

Wireless Sensor networks (WSNs) are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios.

Link-Quality Measurement and Reporting in Wireless Sensor Networks

PubMed Central

Chehri, Abdellah; Jeon, Gwanggil; Choi, Byoungjo

2013-01-01

Wireless Sensor networks (WSNs) are created by small hardware devices that possess the necessary functionalities to measure and exchange a variety of environmental data in their deployment setting. In this paper, we discuss the experiments in deploying a testbed as a first step towards creating a fully functional heterogeneous wireless network-based underground monitoring system. The system is mainly composed of mobile and static ZigBee nodes, which are deployed on the underground mine galleries for measuring ambient temperature. In addition, we describe the measured results of link characteristics such as received signal strength, latency and throughput for different scenarios. PMID:23459389

Heterogeneity in magnetic complex oxides

NASA Astrophysics Data System (ADS)

Arenholz, Elke

Heterogeneity of quantum materials on the nanoscale can result from the spontaneous formation of regions with distinct atomic, electronic and/or magnetic order, and indicates coexistence of competing quantum phases. In complex oxides, the subtle interplay of lattice, charge, orbital, and spin degrees of freedom gives rise to especially rich phase diagrams. For example, coexisting conducting and insulating phases can occur near metal-insulator transitions, colossal magnetoresistance can emerge where ferromagnetic and antiferromagnetic domains compete, and charge-ordered and superconducting regions are present simultaneously in materials exhibiting high-temperature superconductivity. Additionally, externally applied fields (electric, magnetic, or strain) or other external excitations (light or heat) can tip the energy balance towards one phase, or support heterogeneity and phase coexistence and provide the means to perturb and tailor quantum heterogeneity at the nanoscale. Engineering nanomaterials, with structural, electronic and magnetic characteristics beyond what is found in bulk materials, is possible today through the technique of thin film epitaxy, effectively a method of `spray painting' atoms on single crystalline substrates to create precisely customized layered structures with atomic arrangements defined by the underlying substrate. Charge transfer and spin polarization across interfaces as well as imprinting nanoscale heterogeneity between adjacent layers lead to intriguing and important new phenomena testing our understanding of basic physics and creating new functionalities. Moreover, the abrupt change of orientation of an order parameter between nanoscale domains can lead to unique phases that are localized at domain walls, including conducting domain walls in insulating ferroelectrics, and ferromagnetic domain walls in antiferromagnets. Here we present our recent results on tailoring the electronic anisotropy of multiferroic heterostructures by imprinting the BiFeO3 domain pattern in an adjacent La0.7Sr0.3MnO3 layer, understanding the metal-insulator transition in strained VO2 thin films and identifying a three-dimensional quasi-long-range electronic supermodulation in YBa2Cu3O7-x/La0.7Ca0.3MnO3 heterostructures. The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

Patterns of gender equality at workplaces and psychological distress.

PubMed

Elwér, Sofia; Harryson, Lisa; Bolin, Malin; Hammarström, Anne

2013-01-01

Research in the field of occupational health often uses a risk factor approach which has been criticized by feminist researchers for not considering the combination of many different variables that are at play simultaneously. To overcome this shortcoming this study aims to identify patterns of gender equality at workplaces and to investigate how these patterns are associated with psychological distress. Questionnaire data from the Northern Swedish Cohort (n = 715) have been analysed and supplemented with register data about the participants' workplaces. The register data were used to create gender equality indicators of women/men ratios of number of employees, educational level, salary and parental leave. Cluster analysis was used to identify patterns of gender equality at the workplaces. Differences in psychological distress between the clusters were analysed by chi-square test and logistic regression analyses, adjusting for individual socio-demographics and previous psychological distress. The cluster analysis resulted in six distinctive clusters with different patterns of gender equality at the workplaces that were associated to psychological distress for women but not for men. For women the highest odds of psychological distress was found on traditionally gender unequal workplaces. The lowest overall occurrence of psychological distress as well as same occurrence for women and men was found on the most gender equal workplaces. The results from this study support the convergence hypothesis as gender equality at the workplace does not only relate to better mental health for women, but also more similar occurrence of mental ill-health between women and men. This study highlights the importance of utilizing a multidimensional view of gender equality to understand its association to health outcomes. Health policies need to consider gender equality at the workplace level as a social determinant of health that is of importance for reducing differences in health outcomes for women and men.

Impact of Heterogeneity in Sexual Behavior on Effectiveness in Reducing HIV Transmission with Test-and-Treat Strategy.

PubMed

Rozhnova, Ganna; van der Loeff, Maarten F Schim; Heijne, Janneke C M; Kretzschmar, Mirjam E

2016-08-01

The WHO's early-release guideline for antiretroviral treatment (ART) of HIV infection based on a recent trial conducted in 34 countries recommends starting treatment immediately upon an HIV diagnosis. Therefore, the test-and-treat strategy may become more widely used in an effort to scale up HIV treatment and curb further transmission. Here we examine behavioural determinants of HIV transmission and how heterogeneity in sexual behaviour influences the outcomes of this strategy. Using a deterministic model, we perform a systematic investigation into the effects of various mixing patterns in a population of men who have sex with men (MSM), stratified by partner change rates, on the elimination threshold and endemic HIV prevalence. We find that both the level of overdispersion in the distribution of the number of sexual partners and mixing between population subgroups have a large influence on endemic prevalence before introduction of ART and on possible long term effectiveness of ART. Increasing heterogeneity in risk behavior may lead to lower endemic prevalence levels, but requires higher coverage levels of ART for elimination. Elimination is only feasible for populations with a rather low degree of assortativeness of mixing and requires treatment coverage of almost 80% if rates of testing and treatment uptake by all population subgroups are equal. In this case, for fully assortative mixing and 80% coverage endemic prevalence is reduced by 57%. In the presence of heterogeneity in ART uptake, elimination is easier to achieve when the subpopulation with highest risk behavior is tested and treated more often than the rest of the population, and vice versa when it is less. The developed framework can be used to extract information on behavioral heterogeneity from existing data which is otherwise hard to determine from population surveys.

Impact of Heterogeneity in Sexual Behavior on Effectiveness in Reducing HIV Transmission with Test-and-Treat Strategy

PubMed Central

Rozhnova, Ganna; van der Loeff, Maarten F. Schim; Heijne, Janneke C. M.; Kretzschmar, Mirjam E.

2016-01-01

The WHO’s early-release guideline for antiretroviral treatment (ART) of HIV infection based on a recent trial conducted in 34 countries recommends starting treatment immediately upon an HIV diagnosis. Therefore, the test-and-treat strategy may become more widely used in an effort to scale up HIV treatment and curb further transmission. Here we examine behavioural determinants of HIV transmission and how heterogeneity in sexual behaviour influences the outcomes of this strategy. Using a deterministic model, we perform a systematic investigation into the effects of various mixing patterns in a population of men who have sex with men (MSM), stratified by partner change rates, on the elimination threshold and endemic HIV prevalence. We find that both the level of overdispersion in the distribution of the number of sexual partners and mixing between population subgroups have a large influence on endemic prevalence before introduction of ART and on possible long term effectiveness of ART. Increasing heterogeneity in risk behavior may lead to lower endemic prevalence levels, but requires higher coverage levels of ART for elimination. Elimination is only feasible for populations with a rather low degree of assortativeness of mixing and requires treatment coverage of almost 80% if rates of testing and treatment uptake by all population subgroups are equal. In this case, for fully assortative mixing and 80% coverage endemic prevalence is reduced by 57%. In the presence of heterogeneity in ART uptake, elimination is easier to achieve when the subpopulation with highest risk behavior is tested and treated more often than the rest of the population, and vice versa when it is less. The developed framework can be used to extract information on behavioral heterogeneity from existing data which is otherwise hard to determine from population surveys. PMID:27479074

A multiple-point geostatistical method for characterizing uncertainty of subsurface alluvial units and its effects on flow and transport

USGS Publications Warehouse

Cronkite-Ratcliff, C.; Phelps, G.A.; Boucher, A.

2012-01-01

This report provides a proof-of-concept to demonstrate the potential application of multiple-point geostatistics for characterizing geologic heterogeneity and its effect on flow and transport simulation. The study presented in this report is the result of collaboration between the U.S. Geological Survey (USGS) and Stanford University. This collaboration focused on improving the characterization of alluvial deposits by incorporating prior knowledge of geologic structure and estimating the uncertainty of the modeled geologic units. In this study, geologic heterogeneity of alluvial units is characterized as a set of stochastic realizations, and uncertainty is indicated by variability in the results of flow and transport simulations for this set of realizations. This approach is tested on a hypothetical geologic scenario developed using data from the alluvial deposits in Yucca Flat, Nevada. Yucca Flat was chosen as a data source for this test case because it includes both complex geologic and hydrologic characteristics and also contains a substantial amount of both surface and subsurface geologic data. Multiple-point geostatistics is used to model geologic heterogeneity in the subsurface. A three-dimensional (3D) model of spatial variability is developed by integrating alluvial units mapped at the surface with vertical drill-hole data. The SNESIM (Single Normal Equation Simulation) algorithm is used to represent geologic heterogeneity stochastically by generating 20 realizations, each of which represents an equally probable geologic scenario. A 3D numerical model is used to simulate groundwater flow and contaminant transport for each realization, producing a distribution of flow and transport responses to the geologic heterogeneity. From this distribution of flow and transport responses, the frequency of exceeding a given contaminant concentration threshold can be used as an indicator of uncertainty about the location of the contaminant plume boundary.

Concurrent heterogeneous neural model simulation on real-time neuromimetic hardware.

PubMed

Rast, Alexander; Galluppi, Francesco; Davies, Sergio; Plana, Luis; Patterson, Cameron; Sharp, Thomas; Lester, David; Furber, Steve

2011-11-01

Dedicated hardware is becoming increasingly essential to simulate emerging very-large-scale neural models. Equally, however, it needs to be able to support multiple models of the neural dynamics, possibly operating simultaneously within the same system. This may be necessary either to simulate large models with heterogeneous neural types, or to simplify simulation and analysis of detailed, complex models in a large simulation by isolating the new model to a small subpopulation of a larger overall network. The SpiNNaker neuromimetic chip is a dedicated neural processor able to support such heterogeneous simulations. Implementing these models on-chip uses an integrated library-based tool chain incorporating the emerging PyNN interface that allows a modeller to input a high-level description and use an automated process to generate an on-chip simulation. Simulations using both LIF and Izhikevich models demonstrate the ability of the SpiNNaker system to generate and simulate heterogeneous networks on-chip, while illustrating, through the network-scale effects of wavefront synchronisation and burst gating, methods that can provide effective behavioural abstractions for large-scale hardware modelling. SpiNNaker's asynchronous virtual architecture permits greater scope for model exploration, with scalable levels of functional and temporal abstraction, than conventional (or neuromorphic) computing platforms. The complete system illustrates a potential path to understanding the neural model of computation, by building (and breaking) neural models at various scales, connecting the blocks, then comparing them against the biology: computational cognitive neuroscience. Copyright © 2011 Elsevier Ltd. All rights reserved.

Coarse-Grained Descriptions of Dynamics for Networks with Both Intrinsic and Structural Heterogeneities

PubMed Central

Bertalan, Tom; Wu, Yan; Laing, Carlo; Gear, C. William; Kevrekidis, Ioannis G.

2017-01-01

Finding accurate reduced descriptions for large, complex, dynamically evolving networks is a crucial enabler to their simulation, analysis, and ultimately design. Here, we propose and illustrate a systematic and powerful approach to obtaining good collective coarse-grained observables—variables successfully summarizing the detailed state of such networks. Finding such variables can naturally lead to successful reduced dynamic models for the networks. The main premise enabling our approach is the assumption that the behavior of a node in the network depends (after a short initial transient) on the node identity: a set of descriptors that quantify the node properties, whether intrinsic (e.g., parameters in the node evolution equations) or structural (imparted to the node by its connectivity in the particular network structure). The approach creates a natural link with modeling and “computational enabling technology” developed in the context of Uncertainty Quantification. In our case, however, we will not focus on ensembles of different realizations of a problem, each with parameters randomly selected from a distribution. We will instead study many coupled heterogeneous units, each characterized by randomly assigned (heterogeneous) parameter value(s). One could then coin the term Heterogeneity Quantification for this approach, which we illustrate through a model dynamic network consisting of coupled oscillators with one intrinsic heterogeneity (oscillator individual frequency) and one structural heterogeneity (oscillator degree in the undirected network). The computational implementation of the approach, its shortcomings and possible extensions are also discussed. PMID:28659781

Structure formation and properties of a copper-aluminum joint produced by ultrasound-assisted explosive welding

NASA Astrophysics Data System (ADS)

Kuz'min, E. V.; Peev, A. P.; Kuz'min, S. V.; Lysak, V. I.

2017-08-01

The effect of ultrasound-assisted explosive welding on the structure formation and the properties of copper-aluminum joints is studied. Ultrasound-assisted explosive welding improves the quality of formed copper-aluminum joints, i.e., enhances their strength and significantly reduces the amount of fused metal over the entire weldability range. It is shown that ultrasound-assisted explosive welding can noticeably extend the weldability range of the copper-aluminum pair to obtain equal-in-strength joints with minimum structural heterogeneity in the wide welding range.

Madelung's Disease - Case Series and Treatment by Tumescent Liposuction or Lipectomy.

PubMed

Wollina, Uwe; Heinig, Birgit

2017-07-25

Madelung disease is a disfiguring disorder belonging to the heterogeneous group of lipomatosis. The aetiology is not well understood, but alcohol consumption has been regarded as of importance. The reported incidence is about 1 in 25,000 inhabitants. We reviewed our files of the last ten years and identified eight adult patients with an equal gender distribution. Their age was between 60 and 85 years of life. Comorbidities are frequent. Clinical presentation may vary. Surgical treatment is reported and discussed. Both cold steel surgery and tumescent liposuction have their place in treatment.

Preservation of Earth-forming events in the tungsten isotopic composition of modern flood basalts.

PubMed

Rizo, Hanika; Walker, Richard J; Carlson, Richard W; Horan, Mary F; Mukhopadhyay, Sujoy; Manthos, Vicky; Francis, Don; Jackson, Matthew G

2016-05-13

How much of Earth's compositional variation dates to processes that occurred during planet formation remains an unanswered question. High-precision tungsten isotopic data from rocks from two large igneous provinces, the North Atlantic Igneous Province and the Ontong Java Plateau, reveal preservation to the Phanerozoic of tungsten isotopic heterogeneities in the mantle. These heterogeneities, caused by the decay of hafnium-182 in mantle domains with high hafnium/tungsten ratios, were created during the first ~50 million years of solar system history, indicating that portions of the mantle that formed during Earth's primary accretionary period have survived to the present. Copyright © 2016, American Association for the Advancement of Science.

Anatomy of Data Integration

PubMed Central

Brazhnik, Olga; Jones, John F.

2007-01-01

Producing reliable information is the ultimate goal of data processing. The ocean of data created with the advances of science and technologies calls for integration of data coming from heterogeneous sources that are diverse in their purposes, business rules, underlying models and enabling technologies. Reference models, Semantic Web, standards, ontology, and other technologies enable fast and efficient merging of heterogeneous data, while the reliability of produced information is largely defined by how well the data represent the reality. In this paper we initiate a framework for assessing the informational value of data that includes data dimensions; aligning data quality with business practices; identifying authoritative sources and integration keys; merging models; uniting updates of varying frequency and overlapping or gapped data sets. PMID:17071142

Effects of Part-based Similarity on Visual Search: The Frankenbear Experiment

PubMed Central

Alexander, Robert G.; Zelinsky, Gregory J.

2012-01-01

Do the target-distractor and distractor-distractor similarity relationships known to exist for simple stimuli extend to real-world objects, and are these effects expressed in search guidance or target verification? Parts of photorealistic distractors were replaced with target parts to create four levels of target-distractor similarity under heterogenous and homogenous conditions. We found that increasing target-distractor similarity and decreasing distractor-distractor similarity impaired search guidance and target verification, but that target-distractor similarity and heterogeneity/homogeneity interacted only in measures of guidance; distractor homogeneity lessens effects of target-distractor similarity by causing gaze to fixate the target sooner, not by speeding target detection following its fixation. PMID:22227607

SU-F-R-13: Decoding 18F-FDG Uptake Heterogeneity for Primary and Lymphoma Tumors by Using Texture Analysis in PET Images

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

Ma, C; Yin, Y

Purpose: To explore 18F-FDG uptake heterogeneity of primary tumor and lymphoma tumor by texture features of PET image and quantify the heterogeneity difference between primary tumor and lymphoma tumor. Methods: 18 patients with primary tumor and lymphoma tumor in lung cancer were enrolled. All patients underwent whole-body 18F-FDG PET/CT scans before treatment. Texture features, based on Gray-level Co-occurrence Matrix, second and high order matrices are extracted from code using MATLAB software to quantify 18F-FDG uptake heterogeneity. The relationships of volume between energy, entropy, correlation, homogeneity and contrast were analyzed. Results: For different cases, tumor heterogeneity was not the same. Texturemore » parameters (contrast, entropy, and correlation) of lymphoma were lower than primary tumor. On the contrast, the texture parameters (energy, homogeneity and inverse different moment) of lymphoma were higher than primary tumor. Significantly, correlations were observed between volume and energy (primary, r=−0.194, p=0.441; lymphoma, r=−0.339, p=0.582), homogeneity (primary, r=−0.146, p=0.382; lymphoma, r=−0.193, p=0.44), inverse difference moment (primary, r=−0.14, p=0.374; lymphoma, r=−0.172, p=0.414) and a positive correlation between volume and entropy (primary, r=0.233, p=0.483; lymphoma, r=0.462, p=0.680), contrast (primary, r=0.159, p=0.399; lymphoma, r=0.341, p=0.584), correlation (primary, r=0.027, p=0.165; lymphoma, r=0.046, p=0.215). For the same patient, energy for primary and lymphoma tumor is equal. The volume of lymphoma is smaller than primary tumor, but the homogeneity were higher than primary tumor. Conclusion: This study showed that there were effective heterogeneity differences between primary and lymphoma tumor by FDG-PET image texture analysis.« less

Quantitative trait loci analysis for resistance to Cephalosporium stripe, a vascular wilt disease of wheat.

PubMed

Quincke, Martin C; Peterson, C James; Zemetra, Robert S; Hansen, Jennifer L; Chen, Jianli; Riera-Lizarazu, Oscar; Mundt, Christopher C

2011-05-01

Cephalosporium stripe, caused by Cephalosporium gramineum, can cause severe loss of wheat (Triticum aestivum L.) yield and grain quality and can be an important factor limiting adoption of conservation tillage practices. Selecting for resistance to Cephalosporium stripe is problematic; however, as optimum conditions for disease do not occur annually under natural conditions, inoculum levels can be spatially heterogeneous, and little is known about the inheritance of resistance. A population of 268 recombinant inbred lines (RILs) derived from a cross between two wheat cultivars was characterized using field screening and molecular markers to investigate the inheritance of resistance to Cephalosporium stripe. Whiteheads (sterile heads caused by pathogen infection) were measured on each RIL in three field environments under artificially inoculated conditions. A linkage map for this population was created based on 204 SSR and DArT markers. A total of 36 linkage groups were resolved, representing portions of all chromosomes except for chromosome 1D, which lacked a sufficient number of polymorphic markers. Quantitative trait locus (QTL) analysis identified seven regions associated with resistance to Cephalosporium stripe, with approximately equal additive effects. Four QTL derived from the more susceptible parent (Brundage) and three came from the more resistant parent (Coda), but the cumulative, additive effect of QTL from Coda was greater than that of Brundage. Additivity of QTL effects was confirmed through regression analysis and demonstrates the advantage of accumulating multiple QTL alleles to achieve high levels of resistance.

Structural classification of marshes with Polarimetric SAR highlighting the temporal mapping of marshes exposed to oil

USGS Publications Warehouse

Ramsey, Elijah W.; Rangoonwala, Amina; Jones, Cathleen E.

2015-01-01

Empirical relationships between field-derived Leaf Area Index (LAI) and Leaf Angle Distribution (LAD) and polarimetric synthetic aperture radar (PolSAR) based biophysical indicators were created and applied to map S. alterniflora marsh canopy structure. PolSAR and field data were collected near concurrently in the summers of 2010, 2011, and 2012 in coastal marshes, and PolSAR data alone were acquired in 2009. Regression analyses showed that LAI correspondence with the PolSAR biophysical indicator variables equaled or exceeded those of vegetation water content (VWC) correspondences. In the final six regressor model, the ratio HV/VV explained 49% of the total 77% explained LAI variance, and the HH-VV coherence and phase information accounted for the remainder. HV/HH dominated the two regressor LAD relationship, and spatial heterogeneity and backscatter mechanism followed by coherence information dominated the final three regressor model that explained 74% of the LAD variance. Regression results applied to 2009 through 2012 PolSAR images showed substantial changes in marsh LAI and LAD. Although the direct cause was not substantiated, following a release of freshwater in response to the 2010 Deepwater Horizon oil spill, the fairly uniform interior marsh structure of 2009 was more vertical and dense shortly after the oil spill cessation. After 2010, marsh structure generally progressed back toward the 2009 uniformity; however, the trend was more disjointed in oil impact marshes.             

Determination of the Optimal Fourier Number on the Dynamic Thermal Transmission

NASA Astrophysics Data System (ADS)

Bruzgevičius, P.; Burlingis, A.; Norvaišienė, R.

2016-12-01

This article represents the result of experimental research on transient heat transfer in a multilayered (heterogeneous) wall. Our non-steady thermal transmission simulation is based on a finite-difference calculation method. The value of a Fourier number shows the similarity of thermal variation in conditional layers of an enclosure. Most scientists recommend using no more than a value of 0.5 for the Fourier number when performing calculations on dynamic (transient) heat transfer. The value of the Fourier number is determined in order to acquire reliable calculation results with optimal accuracy. To compare the results of simulation with experimental research, a transient heat transfer calculation spreadsheet was created. Our research has shown that a Fourier number of around 0.5 or even 0.32 is not sufficient ({≈ }17 % of oscillation amplitude) for calculations of transient heat transfer in a multilayered wall. The least distorted calculation results were obtained when the multilayered enclosure was divided into conditional layers with almost equal Fourier number values and when the value of the Fourier number was around 1/6, i.e., approximately 0.17. Statistical deviation analysis using the Statistical Analysis System was applied to assess the accuracy of the spreadsheet calculation and was developed on the basis of our established methodology. The mean and median absolute error as well as their confidence intervals has been estimated by the two methods with optimal accuracy ({F}_{oMDF}= 0.177 and F_{oEPS}= 0.1633 values).

Age Discrimination in Employment Act; retiree health benefits. Final rule.

PubMed

2007-12-26

The Equal Employment Opportunity Commission is publishing this final rule so that employers may create, adopt, and maintain a wide range of retiree health plan designs, such as Medicare bridge plans and Medicare wrap-around plans, without violating the Age Discrimination in Employment Act of 1967 (ADEA). To address concerns that the ADEA may be construed to create an incentive for employers to eliminate or reduce retiree health benefits, EEOC is creating a narrow exemption from the prohibitions of the ADEA for the practice of coordinating employer-sponsored retiree health benefits with eligibility for Medicare or a comparable State health benefits program. The rule does not otherwise affect an employer's ability to offer health or other employment benefits to retirees, consistent with the law.

Samoa's Education Policy: Negotiating a Hybrid Space for Values

ERIC Educational Resources Information Center

Tuia, Tagataese Tupu; Iyer, Radha

2015-01-01

This paper analyses the education policy of Samoa to examine the values that are presented within as relevant to the education system. Drawing on the theory of postcolonialism and globalization, we illustrate how the global and local interact within the education policy to create a hybrid, heterogeneous mix of values and, while the policy…

Public Discourse: Creating the Conditions for Dialogue Concerning the Common Good in a Postmodern Heterogeneous Democracy.

ERIC Educational Resources Information Center

Geren, Peggy Ruth

2001-01-01

Offers a philosophical history of the nature of public discourse, describing it as a basic constituent of human rights. Analyzes the dichotomy between the common good and tolerance and protection of pluralism. Discusses the philosophical views of Condorcet, Jefferson, Dewey, and Habermas, portraying public discourse in relation to the…

Managing landscapes at multiple scales for sustainability of ecosystem functions (Preface)

Treesearch

R.A. Birdsey; R. Lucas; Y. Pan; G. Sun; E.J. Gustafson; A.H.  Perera

2010-01-01

The science of landscape ecology is a rapidly evolving academic field with an emphasis on studying large-scale spatial heterogeneity created by natural influences and human activities. These advances have important implications for managing and conserving natural resources. At a September 2008 IUFRO conference in Chengdu, Sichuan, P.R. China, we highlighted both the...

Effects of Cooperative Writing with Embedded Multimedia: A Randomized Experiment

ERIC Educational Resources Information Center

Madden, Nancy A.; Slavin, Robert E.; Logan, Michele

2011-01-01

The present study represented an effort to improve on the outcomes of the Puma (2006) study by creating a writing process program that provided students with compelling video models of effective writing practices in small writing teams. In this method, called Writing Wings with Media (WWM), students worked in 4-member, heterogeneous writing groups…

Positing a difference between acts and omissions: the principle of justice, Rachels' cases and moral weakness.

PubMed

Mohindra, R

2009-05-01

The difficulty in discovering a difference between killing and letting die has led many philosophers to deny the distinction. This paper seeks to develop an argument defending the distinction between killing and letting die. In relation to Rachels' cases, the argument is that (a) even accepting that Smith and Jones may select equally heinous options from the choices they have available to them, (b) the fact that the choices available to them are different is morally relevant, and (c) this difference in available choices can be used to distinguish between the agents in certain circumstances. It is the principle of justice, as espoused by Aristotle, which requires that equal things are treated equally and that unequal things are treated unequally that creates a presumption that Smith and Jones should be treated differently. The magnitude of this difference can be amplified by other premises, making the distinction morally relevant in practical reality.

Scale Dependence of Cirrus Horizontal Heterogeneity Effects on TOA Measurements. Part I; MODIS Brightness Temperatures in the Thermal Infrared

NASA Technical Reports Server (NTRS)

Fauchez, Thomas; Platnick, Steven; Meyer, Kerry; Cornet, Celine; Szczap, Frederic; Varnai, Tamas

2017-01-01

This paper presents a study on the impact of cirrus cloud heterogeneities on MODIS simulated thermal infrared (TIR) brightness temperatures (BTs) at the top of the atmosphere (TOA) as a function of spatial resolution from 50 meters to 10 kilometers. A realistic 3-D (three-dimensional) cirrus field is generated by the 3DCLOUD model (average optical thickness of 1.4, cloudtop and base altitudes at 10 and 12 kilometers, respectively, consisting of aggregate column crystals of D (sub eff) equals 20 microns), and 3-D thermal infrared radiative transfer (RT) is simulated with the 3DMCPOL (3-D Monte Carlo Polarized) code. According to previous studies, differences between 3-D BT computed from a heterogenous pixel and 1-D (one-dimensional) RT computed from a homogeneous pixel are considered dependent at nadir on two effects: (i) the optical thickness horizontal heterogeneity leading to the plane-parallel homogeneous bias (PPHB); and the (ii) horizontal radiative transport (HRT) leading to the independent pixel approximation error (IPAE). A single but realistic cirrus case is simulated and, as expected, the PPHB mainly impacts the low-spatial resolution results (above approximately 250 meters), with averaged values of up to 5-7 K (thousand), while the IPAE mainly impacts the high-spatial resolution results (below approximately 250 meters) with average values of up to 1-2 K (thousand). A sensitivity study has been performed in order to extend these results to various cirrus optical thicknesses and heterogeneities by sampling the cirrus in several ranges of parameters. For four optical thickness classes and four optical heterogeneity classes, we have found that, for nadir observations, the spatial resolution at which the combination of PPHB and HRT effects is the smallest, falls between 100 and 250 meters. These spatial resolutions thus appear to be the best choice to retrieve cirrus optical properties with the smallest cloud heterogeneity-related total bias in the thermal infrared. For off-nadir observations, the average total effect is increased and the minimum is shifted to coarser spatial resolutions.

Creating multithemed ecological regions for macroscale ecology: Testing a flexible, repeatable, and accessible clustering method

USGS Publications Warehouse

Cheruvelil, Kendra Spence; Yuan, Shuai; Webster, Katherine E.; Tan, Pang-Ning; Lapierre, Jean-Francois; Collins, Sarah M.; Fergus, C. Emi; Scott, Caren E.; Norton Henry, Emily; Soranno, Patricia A.; Filstrup, Christopher T.; Wagner, Tyler

2017-01-01

Understanding broad-scale ecological patterns and processes often involves accounting for regional-scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question—How well do these regions capture regional-scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km2); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft-ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation—approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional scale. Our results demonstrate the usefulness of this method for creating customizable and reproducible regions for research and management applications.

Creating multithemed ecological regions for macroscale ecology: Testing a flexible, repeatable, and accessible clustering method.

PubMed

Cheruvelil, Kendra Spence; Yuan, Shuai; Webster, Katherine E; Tan, Pang-Ning; Lapierre, Jean-François; Collins, Sarah M; Fergus, C Emi; Scott, Caren E; Henry, Emily Norton; Soranno, Patricia A; Filstrup, Christopher T; Wagner, Tyler

2017-05-01

Understanding broad-scale ecological patterns and processes often involves accounting for regional-scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question-How well do these regions capture regional-scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km 2 ); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft-ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation-approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional scale. Our results demonstrate the usefulness of this method for creating customizable and reproducible regions for research and management applications.

HeNCE: A Heterogeneous Network Computing Environment

DOE PAGES

Beguelin, Adam; Dongarra, Jack J.; Geist, George Al; ...

1994-01-01

Network computing seeks to utilize the aggregate resources of many networked computers to solve a single problem. In so doing it is often possible to obtain supercomputer performance from an inexpensive local area network. The drawback is that network computing is complicated and error prone when done by hand, especially if the computers have different operating systems and data formats and are thus heterogeneous. The heterogeneous network computing environment (HeNCE) is an integrated graphical environment for creating and running parallel programs over a heterogeneous collection of computers. It is built on a lower level package called parallel virtual machine (PVM).more » The HeNCE philosophy of parallel programming is to have the programmer graphically specify the parallelism of a computation and to automate, as much as possible, the tasks of writing, compiling, executing, debugging, and tracing the network computation. Key to HeNCE is a graphical language based on directed graphs that describe the parallelism and data dependencies of an application. Nodes in the graphs represent conventional Fortran or C subroutines and the arcs represent data and control flow. This article describes the present state of HeNCE, its capabilities, limitations, and areas of future research.« less

Estimation of the frequency of occult mutations for an autosomal recessive disease in the presence of genetic heterogeneity: application to genetic hearing loss disorders.

PubMed

Kimberling, William J

2005-11-01

The routine testing for pathologic mutation(s) in a patient's DNA has become the foundation of modern molecular genetic diagnosis. It is especially valuable when the phenotype shows genetic heterogeneity, and its importance will grow as treatments become genotype specific. However, the technology of mutation detection is imperfect and mutations are often missed. This can be especially troublesome when dealing with a recessive disorder where the combination of genetic heterogeneity and missed mutation creates an imprecision in the genotypic assessment of individuals who do not appear to have the expected complement of two pathologic mutations. This article describes a statistical approach to the estimation of the likelihood of a genetic diagnosis under these conditions. In addition to providing a means of testing for missed mutations, it also provides a method of estimating and testing for the presence of genetic heterogeneity in the absence of linkage data. Gene frequencies as well as estimates of sensitivity and specificity can be obtained as well. The test is applied to GJB2 recessive nonsyndromic deafness, Usher syndrome types Ib and IIa, and Pendred-enlarged vestibular aqueduct syndrome. Copyright 2005 Wiley-Liss, Inc.

Kleptothermy: an additional category of thermoregulation, and a possible example in sea kraits (Laticauda laticaudata, Serpentes).

PubMed

Brischoux, François; Bonnet, Xavier; Shine, Richard

2009-12-23

Lacking the capacity for thermogenesis, most ectotherms inhabiting thermally heterogeneous environments rely instead upon exploiting that ambient heterogeneity. In many cases they maintain body temperatures within a narrow range despite massive spatial and temporal variation in ambient conditions. Reliance on diverse thermal opportunities is reflected in specific terms for organisms that bask in sunlight to regulate their temperature (heliotherms), or that press their bodies against warm substrates to facilitate heat flow (thigmotherms), or that rely on large body mass to maintain thermal constancy (gigantothermy). We propose an additional category of thermoregulators: kleptotherms, which regulate their own temperature by 'stealing' heat from other organisms. This concept involves two major conditions: the thermal heterogeneity created by the presence of a warm organism in a cool environment and the selective use of that heterogeneity by another animal to maintain body temperatures at higher (and more stable) levels than would be possible elsewhere in the local area. Kleptothermy occurs in endotherms also, but is usually reciprocal (rather than unilateral as in ectotherms). Thermal monitoring on a small tropical island documents a possible example of kleptothermy, based on high stable temperatures of a sea snake (Laticauda laticaudata) inside a burrow occupied by seabirds.

Fuselets: an agent based architecture for fusion of heterogeneous information and data

NASA Astrophysics Data System (ADS)

Beyerer, Jürgen; Heizmann, Michael; Sander, Jennifer

2006-04-01

A new architecture for fusing information and data from heterogeneous sources is proposed. The approach takes criminalistics as a model. In analogy to the work of detectives, who attempt to investigate crimes, software agents are initiated that pursue clues and try to consolidate or to dismiss hypotheses. Like their human pendants, they can, if questions beyond their competences arise, consult expert agents. Within the context of a certain task, region, and time interval, specialized operations are applied to each relevant information source, e.g. IMINT, SIGINT, ACINT,..., HUMINT, data bases etc. in order to establish hit lists of first clues. Each clue is described by its pertaining facts, uncertainties, and dependencies in form of a local degree-of-belief (DoB) distribution in a Bayesian sense. For each clue an agent is initiated which cooperates with other agents and experts. Expert agents support to make use of different information sources. Consultations of experts, capable to access certain information sources, result in changes of the DoB of the pertaining clue. According to the significance of concentration of their DoB distribution clues are abandoned or pursued further to formulate task specific hypotheses. Communications between the agents serve to find out whether different clues belong to the same cause and thus can be put together. At the end of the investigation process, the different hypotheses are evaluated by a jury and a final report is created that constitutes the fusion result. The approach proposed avoids calculating global DoB distributions by adopting a local Bayesian approximation and thus reduces the complexity of the exact problem essentially. Different information sources are transformed into DoB distributions using the maximum entropy paradigm and considering known facts as constraints. Nominal, ordinal and cardinal quantities can be treated within this framework equally. The architecture is scalable by tailoring the number of agents according to the available computer resources, to the priority of tasks, and to the maximum duration of the fusion process. Furthermore, the architecture allows cooperative work of human and automated agents and experts, as long as not all subtasks can be accomplished automatically.

Challenging Lesbian and Gay Inequalities in Education. Gender and Education Series.

ERIC Educational Resources Information Center

Epstein, Debbie, Ed.

Educators in Britain have tended to ignore lesbian and gay issues, creating a gap that this book addresses by discussing the complex debates about sexuality and schooling. Contributors to this collection tell stories of distress and victimization and of achievement and support in the following: (1) "Introduction: Lesbian and Gay Equality in…

Revenues and Spending of Michigan's Urban, Suburban, Town and Rural School Districts, 2004-2010

ERIC Educational Resources Information Center

Van Beek, Michael

2011-01-01

In the passionate debates over providing equal educational opportunity for all children, it's frequently argued that large financial inequities create challenges for many public schools, particularly those in lower-income urban areas. This study compares the revenues and operating expenditures of Michigan's urban, suburban, town and rural school…

Library Media Center Design Considerations for Physically Disabled Students.

ERIC Educational Resources Information Center

Moy, Patricia J.

Federal legislation ensures that children with physical disabilities should not be denied access to the school library. These children have the same information needs as their peers, and they want equal access to information in the school library media center. To create an accessible and functional school library, many requirements and…

PROGRESS AND PROBLEMS FROM THE SOCIAL SCIENTIST'S VIEWPOINT.

ERIC Educational Resources Information Center

CLARK, KENNETH

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

Student Success and Satisfaction: Analysis of Students' Perception of a Theatre Conservatory Program

ERIC Educational Resources Information Center

Anton, Anita

2010-01-01

All theatre programs are not created equal. This qualitative study set out to determine the graduating students' perception of satisfaction and success after attending a four year conservatory theatre program. I conducted two interviews with seven of the twelve graduating seniors. The initial interview was conducted after graduation, and the…

Learning from Experience: Creating Leadership Capabilities through Computer Simulated Leadership Challenges

ERIC Educational Resources Information Center

Stewart, Alice C.; Black, Sylvia Sloan; Smith-Gratto, Karen; Williams, Jacqueline A.

2007-01-01

Leadership is often described as something that is learned from experience. However, experiences do not often occur within a controlled environment where learning and its impact can be evaluated. In this paper, we investigate the efficacy of two types of learning experiences. University students received leadership training of equal length through…

Voluntary Counter-Reformation: Stepping Up to the Challenge

ERIC Educational Resources Information Center

Graves, William H.

2007-01-01

The political philosophy (from the U.S. Declaration of Independence) that "all men are created equal" succinctly captures the "raison d'etre" and phenomenal successes of American higher education. Today, the deepest commitment to this idea of fair play is affordable access to a higher education that offers the opportunity to cultivate knowledge,…

If Constructively Creative Divergent Thinking Equals Entrepreneur...How Can We Help Create More of Them?

ERIC Educational Resources Information Center

Lipper, Arthur, III

1987-01-01

The early training of children in divergent thinking skills can help foster entrepreneurship. Such training would include activities to develop natural creativity, activities allowing children to win, activities which accept different solutions, teachers who recognize and encourage creative children, and an understanding of basic business…

Assimilation and Affirmative Action in French Education Systems

ERIC Educational Resources Information Center

Langan, Elise S.

2008-01-01

The French education system was created as a means to uphold the republican principles emanating from the Revolution. The first Article of the 1958 French Constitution says the Republic assures equality before the law of all citizens without distinction of origin or race. Theoretically at least, it is not only forbidden to discriminate, but to…

The Women's Center.

ERIC Educational Resources Information Center

Stimpson, Catharine R.; And Others

Barnard College has created a Women's Center that devotes itself to the task of reaffirming the dignity, autonomy, and equality of women. For too long society has held that women are less rational than men, less capable than men, and thus that educating women is less useful than educating men. Replacing myth with fact is the responsibility of…

Mapping out a Career: An Analysis of Geographic Concentration of Occupations

ERIC Educational Resources Information Center

Watson, Audrey

2010-01-01

Not all occupations are created equal when it comes to geographic distribution. Some occupations are concentrated in relatively few geographic areas; others are spread more evenly across the United States. Specific occupations might be clustered in particular types of geographic settings, such as large urban areas or small rural ones. And some…

Assessing Static and Dynamic Influences on Inmate Violence Levels

ERIC Educational Resources Information Center

Steiner, Benjamin

2009-01-01

Inmate misconduct creates problems for other inmates as well as correctional staff. Most empirical assessments of the correlates of inmate misconduct have been conducted at the individual level; however, a facility's level of misconduct may be of equal importance to prison management and state officials because these numbers can reflect order, or…

Inflammatory phenotypes in the intestine of poultry: Not all inflammation is created equally

USDA-ARS?s Scientific Manuscript database

The intestinal tract harbors a diverse community of microbes that have co-evolved with the host immune system. Although many of these microbes execute functions that are critical for host physiology, the host immune system must control the microbial community so that the dynamics of this interdepen...

Botrytis and native grape yeasts – not all interactions are created equal

USDA-ARS?s Scientific Manuscript database

Native yeasts are of increasing interest to grape growers and winemakers in Washington State because of their potential to contribute to vineyard health and wine quality. In this pilot project, we used eleven strains of native yeasts and nine isolates of the Botrytis bunch rot pathogen, all obtained...

Quality Education through Child-Friendly Schools: Resource Allocation for the Protection of Children's Rights

ERIC Educational Resources Information Center

Orkodashvili, Mariam

2010-01-01

The paper discusses the idea and purpose of Child-Friendly Schools (CFSs) initiated by the UNICEF. It analyses the implications of CFSs in terms of improving children's health and nutrition, promoting gender equality, protecting children's rights, re-defining education quality and creating positive psycho-emotional environment at schools.…

Conjunction Errors in Recognition: Emergent Structure and Metacognitive Control

ERIC Educational Resources Information Center

Verde, Michael F.

2010-01-01

Pictures consisted of component halves from either the same photographic scene (SS) or different scenes (DS). SS pictures possessed the emergent property of forming a continuous scene. In Experiment 1, conjunction lures were created by rearranging halves from studied DS pictures into new DS or SS lures. Despite equally familiar components,…

Standing for Just and Right Decisions: The Long, Slow Path to School Safety.

ERIC Educational Resources Information Center

LeCompte, Margaret D.

2000-01-01

Describes one high school's 20-year struggle to create a safe school environment following race riots and sexual harassment of young women. Notes that these ongoing efforts set the pattern for the school's current efforts to provide equal protection for gay, lesbian, bisexual, transgendered, and queer/questioning students. (SM)

Not All Ambiguous Words Are Created Equal: An EEG Investigation of Homonymy and Polysemy

ERIC Educational Resources Information Center

Klepousniotou, Ekaterini; Pike, G. Bruce; Steinhauer, Karsten; Gracco, Vincent

2012-01-01

Event-related potentials (ERPs) were used to investigate the time-course of meaning activation of different types of ambiguous words. Unbalanced homonymous ("pen"), balanced homonymous ("panel"), metaphorically polysemous ("lip"), and metonymically polysemous words ("rabbit") were used in a visual single-word priming delayed lexical decision task.…

Human Rights: The Struggle for Freedom, Dignity and Equality. Resource Guide.

ERIC Educational Resources Information Center

Connecticut State Dept. of Education, Hartford.

Every human being deserves the right to live in freedom and dignity. Yet human rights violations dominate the headlines. In addition to becoming sensitive to human pain and suffering, young adults must also begin the lifelong process of creating, recognizing, and exercising options. This resource guide contains suggested questions and projects…

Anti-Racist Scholarship: An Advocacy. SUNY Series, Social Context of Education.

ERIC Educational Resources Information Center

Scheurich, James Joseph, Ed.

These papers examine the subject of white scholars using anti-racist scholarship within the long-term U.S. civil rights struggle to create real equality. Chapter 1 includes: "Toward a White Discourse on White Racism" (James Joseph Scheurich), "Response to a 'White Discourse on White Racism'" (W. B. Allen), "Advancing a…

Not All Created Equally: Exploring Calculator Use by Students with Mild Intellectual Disability

ERIC Educational Resources Information Center

Yakubova, Gulnoza; Bouck, Emily C.

2014-01-01

Calculators are widely used in mathematics education, yet limited research examines the effects of calculators for students with mild intellectual disability. An alternating treatments design was used to study the effects of calculator types (i.e., scientific and graphing) on the mathematical performance (i.e., computation and word problems) of…

Identifying Reading Problems with Computer-Adaptive Assessments

ERIC Educational Resources Information Center

Merrell, C.; Tymms, P.

2007-01-01

This paper describes the development of an adaptive assessment called Interactive Computerised Assessment System (InCAS) that is aimed at children of a wide age and ability range to identify specific reading problems. Rasch measurement has been used to create the equal interval scales that form each part of the assessment. The rationale for the…

Multi-Level Alignment Model: Transforming Face-to-Face into E-Instructional Programs

ERIC Educational Resources Information Center

Byers, Celina

2005-01-01

Purpose--To suggest to others in the field an approach equally valid for transforming existing courses into online courses and for creating new online courses. Design/methodology/approach--Using the literature for substantiation, this article discusses the current rapid change within organizations, the role of technology in that change, and the…

The Locus of Preparation and Privilege: College Choice and Social Reproduction

ERIC Educational Resources Information Center

Allen, Daniel J.

2012-01-01

Despite the ostensible proposition of American higher education to create a level playing field and advance an individual's life opportunities, the history of access to higher education in the United States has demonstrated a lack of equality in enrollment patterns. This enrollment inequality appears most pronounced when considering family…

Creating a Campus Climate that Truly Values Diversity.

ERIC Educational Resources Information Center

Clements, Evelyn

In 1987 Middlesex Community College in Massachusetts opened two new campuses: one in Lowell, serving primarily Asian and Hispanic students, and the other in Bedford, serving mostly Caucasian students having limited experience with other cultures. To ensure that both campuses were viewed equally and that a tone of racial harmony was established,…

Challenging the Politics of the "Model Minority" Stereotype: A Case for Educational Equality

ERIC Educational Resources Information Center

Yu, Tianlong

2006-01-01

This article examines the political rationale of the "model minority" stereotype about Asian Americans and its ramifications on education. Created by white elites in the 1960s as a device of political control, the model minority stereotype continues to serve the larger conservative restoration in American society today. By…

"Citizen Jane": Rethinking Design Principles for Closing the Gender Gap in Computing.

ERIC Educational Resources Information Center

Raphael, Chad

This paper identifies three rationales in the relevant literature for closing the gender gap in computing: economic, cultural and political. Each rationale implies a different set of indicators of present inequalities, disparate goals for creating equality, and distinct principles for software and web site design that aims to help girls overcome…

Informal Nature Experience on the School Playground

ERIC Educational Resources Information Center

Raith, Andreas

2015-01-01

In Germany, all-day care and all-day schooling are currently increasing on a large-scale. The extended time children spend in educational institutions could potentially result in limited access to nature experience for children. On the other hand, it could equally create opportunities for informal nature experience if school playgrounds have a…

Young Children Create Partner-Specific Referential Pacts with Peers

ERIC Educational Resources Information Center

Köymen, Bahar; Schmerse, Daniel; Lieven, Elena; Tomasello, Michael

2014-01-01

In 2 studies, we investigated how peers establish a "referential pact" to call something, for example, a "cushion" versus a "pillow" (both equally felicitous). In Study 1, pairs of 4-and 6-year-old German-speaking peers established a referential pact for an artifact, for example, a "woman's shoe," in a…

Mother-Adolescent Health Communication: Are All Conversations Created Equally?

ERIC Educational Resources Information Center

Boone, Tanya L.; Lefkowitz, Eva S.

2007-01-01

Fifty-two mother-adolescent dyads (mean adolescent age = 16.3) participated in an observational study of communication about health topics. The aim of the study was to examine mother-adolescent conversations about health issues--drugs/alcohol, sexuality, nutrition/exercise--to determine the extent to which the mothers treat these issues similarly.…

The transcriptome of estrogen-independent mammary growth reveals that not all mammary glands are created equally

USDA-ARS?s Scientific Manuscript database

Allometric growth of ducts in the mammary glands (MG) is widely-held to be estrogen (E)-dependent. We previously discovered that the dietary fatty acid trans-10, cis-12 conjugated linoleic acid (CLA) stimulates E-independent allometric growth and TEB formation in ovariectomized mice. Given the simil...

Reinventing Black Colleges in Postethnic America: The Case of Knoxville College

ERIC Educational Resources Information Center

Hatton, Barbara R.

2011-01-01

As America moves toward the ideals of its founding documents, some scholars have termed it "postethnic America," where culture rather than color or ethnicity will have more influence over the country's affairs. In postethnic America, the country will realize that all "are created equal," and no groups will be treated…

All-Day Schooling: Improving Social and Educational Portuguese Policies

ERIC Educational Resources Information Center

Martins, Jorge; Vale, Ana; Mouraz, Ana

2015-01-01

Over the past decade, several European countries have implemented policies and programmes leading to the introduction of the concept of "all-day schooling," thus acknowledging the need to guarantee the guard of all children and to enhance equal opportunities of success at school. The Portuguese Ministry of Education created and funded…

Emotional Memories Are Not All Created Equal: Evidence for Selective Memory Enhancement

ERIC Educational Resources Information Center

Anderson, Adam K.; Grabski, Wojtek; Lacka, Dominika; Yamaguchi, Yuki

2006-01-01

Human brain imaging studies have shown that greater amygdala activation to emotional relative to neutral events leads to enhanced episodic memory. Other studies have shown that fearful faces also elicit greater amygdala activation relative to neutral faces. To the extent that amygdala recruitment is sufficient to enhance recollection, these…

Corralling Web 2.0: Building an Intranet that Enables Individuals

ERIC Educational Resources Information Center

Etches-Johnson, Amanda; Baird, Catherine

2010-01-01

The days of top-down communication and controlled internal messages at a library organization are--or should be--behind us. Modern libraries must be fluid and flexible organizations with equally nimble internal communication infrastructures in place to keep up with the fast-paced environments that have been created in these organizations. As is…

Authoring Immersive Mixed Reality Experiences

NASA Astrophysics Data System (ADS)

Misker, Jan M. V.; van der Ster, Jelle

Creating a mixed reality experience is a complicated endeavour. From our practice as a media lab in the artistic domain we found that engineering is “only” a first step in creating a mixed reality experience. Designing the appearance and directing the user experience are equally important for creating an engaging, immersive experience. We found that mixed reality artworks provide a very good test bed for studying these topics. This chapter details three steps required for authoring mixed reality experiences: engineering, designing and directing. We will describe a platform (VGE) for creating mixed reality environments that incorporates these steps. A case study (EI4) is presented in which this platform was used to not only engineer the system, but in which an artist was given the freedom to explore the artistic merits of mixed reality as an artistic medium, which involved areas such as the look and feel, multimodal experience and interaction, immersion as a subjective emotion and game play scenarios.

High-throughput heterogeneous catalyst research

NASA Astrophysics Data System (ADS)

Turner, Howard W.; Volpe, Anthony F., Jr.; Weinberg, W. H.

2009-06-01

With the discovery of abundant and low cost crude oil in the early 1900's came the need to create efficient conversion processes to produce low cost fuels and basic chemicals. Enormous investment over the last century has led to the development of a set of highly efficient catalytic processes which define the modern oil refinery and which produce most of the raw materials and fuels used in modern society. Process evolution and development has led to a refining infrastructure that is both dominated and enabled by modern heterogeneous catalyst technologies. Refineries and chemical manufacturers are currently under intense pressure to improve efficiency, adapt to increasingly disadvantaged feedstocks including biomass, lower their environmental footprint, and continue to deliver their products at low cost. This pressure creates a demand for new and more robust catalyst systems and processes that can accommodate them. Traditional methods of catalyst synthesis and testing are slow and inefficient, particularly in heterogeneous systems where the structure of the active sites is typically complex and the reaction mechanism is at best ill-defined. While theoretical modeling and a growing understanding of fundamental surface science help guide the chemist in designing and synthesizing targets, even in the most well understood areas of catalysis, the parameter space that one needs to explore experimentally is vast. The result is that the chemist using traditional methods must navigate a complex and unpredictable diversity space with a limited data set to make discoveries or to optimize known systems. We describe here a mature set of synthesis and screening technologies that together form a workflow that breaks this traditional paradigm and allows for rapid and efficient heterogeneous catalyst discovery and optimization. We exemplify the power of these new technologies by describing their use in the development and commercialization of a novel catalyst for the hydrodesulfurization of gasoline distillates having 50% more selectivity and 30% more activity for sulfur removal than the state-of-the-art commercial reference.

Monolithic Hydrogen Peroxide Catalyst Bed Development

NASA Technical Reports Server (NTRS)

Ponzo, J. B.

2003-01-01

With recent increased industry and government interest in rocket grade hydrogen peroxide as a viable propellant, significant effort has been expended to improve on earlier developments. This effort has been predominately centered in improving heterogeneous. typically catalyst beds; and homogeneous catalysts, which are typically solutions of catalytic substances. Heterogeneous catalyst beds have traditionally consisted of compressed wire screens plated with a catalytic substance, usually silver, and were used m many RCS applications (X-1, Mercury, and Centaur for example). Aerojet has devised a heterogeneous catalyst design that is monolithic (single piece), extremely compact, and has pressure drops equal to or less than traditional screen beds. The design consists of a bonded stack of very thin, photoetched metal plates, silver coated. This design leads to a high surface area per unit volume and precise flow area, resulting in high, stable, and repeatable performance. Very high throughputs have been demonstrated with 90% hydrogen peroxide. (0.60 lbm/s/sq in at 1775-175 psia) with no flooding of the catalyst bed. Bed life of over 900 seconds has also been demonstrated at throughputs of 0.60 lbm/s/sq in across varying chamber pressures. The monolithic design also exhibits good starting performance, short break-in periods, and will easily scale to various sizes.

Investigating the spectral characteristics of backscattering from heterogeneous spheroidal nuclei using broadband finite-difference time-domain simulations

NASA Astrophysics Data System (ADS)

Chao, Guo-Shan; Sung, Kung-Bin

2010-02-01

Backscattered light spectra have been used to extract size distribution of cell nuclei in epithelial tissues for noninvasive detection of precancerous lesions. In existing experimental studies, size estimation is achieved by assuming nuclei as homogeneous spheres or spheroids and fitting the measured data with models based on Mie theory. However, the validity of simplifying nuclei as homogeneous spheres has not been thoroughly examined. In this study, we investigate the spectral characteristics of backscattering from models of spheroidal nuclei under plane wave illumination using three-dimensional finite-difference time-domain (FDTD) simulation. A modulated Gaussian pulse is used to obtain wavelength dependent scattering intensity with a single FDTD run. The simulated model of nuclei consists of a nucleolus and randomly distributed chromatin condensation in homogeneous cytoplasm and nucleoplasm. The results show that backscattering spectra from spheroidal nuclei have similar oscillating patterns to those from homogeneous spheres with the diameter equal to the projective length of the spheroidal nucleus along the propagation direction. The strength of backscattering is enhanced in heterogeneous spheroids as compared to homogeneous spheroids. The degree of which backscattering spectra of heterogeneous nuclei deviate from Mie theory is highly dependent on the distribution of chromatin/nucleolus but not sensitive to nucleolar size, refractive index fluctuation or chromatin density.

Studies on the structure of sphingomyelinase. Amino acid composition and heterogeneity on isoelectric focusing.

PubMed Central

Jones, C S; Shankaran, P; Davidson, D J; Poulos, A; Callahan, J W

1983-01-01

Sphingomyelinase, purified to apparent homogeneity from human placenta, is an acidic protein, as judged from its amino acid composition and by isoelectric focusing of the carboxymethylated protein. The amino acid composition is characterized by an approximately equal content of hydrophobic and polar amino acid residues. The reduced-alkylated polypeptides were separated into two groups. Most of the polypeptides were heterogeneous with pI values of 4.4-5.0, but an additional more minor component was observed at pI 5.4. Liquid isoelectric focusing resolved the purified enzyme into a single major component (pI 4.7-4.8), a minor component (pI 5.0-5.4) and a plateau region of activity (pI 6-7). On thin-layer isoelectric focusing, the protein profile obtained from each of these regions was the same. In addition, the substrate specificity, Km values and effect of inhibitory substances were identical. We conclude that sphingomyelinase is an acidic, microheterogeneous protein that likely exists as a holopolymer of a single major polypeptide chain. the heterogeneity of the intact protein on isoelectric focusing appears to reflect this microheterogeneity, which is influenced by a tendency to associate with itself and with detergents such as Triton X-100. Images Fig. 1. Fig. 2. Fig. 4. PMID:6303305

A Versatile Omnibus Test for Detecting Mean and Variance Heterogeneity

PubMed Central

Bailey, Matthew; Kauwe, John S. K.; Maxwell, Taylor J.

2014-01-01

Recent research has revealed loci that display variance heterogeneity through various means such as biological disruption, linkage disequilibrium (LD), gene-by-gene (GxG), or gene-by-environment (GxE) interaction. We propose a versatile likelihood ratio test that allows joint testing for mean and variance heterogeneity (LRTMV) or either effect alone (LRTM or LRTV) in the presence of covariates. Using extensive simulations for our method and others we found that all parametric tests were sensitive to non-normality regardless of any trait transformations. Coupling our test with the parametric bootstrap solves this issue. Using simulations and empirical data from a known mean-only functional variant we demonstrate how linkage disequilibrium (LD) can produce variance-heterogeneity loci (vQTL) in a predictable fashion based on differential allele frequencies, high D’ and relatively low r2 values. We propose that a joint test for mean and variance heterogeneity is more powerful than a variance only test for detecting vQTL. This takes advantage of loci that also have mean effects without sacrificing much power to detect variance only effects. We discuss using vQTL as an approach to detect gene-by-gene interactions and also how vQTL are related to relationship loci (rQTL) and how both can create prior hypothesis for each other and reveal the relationships between traits and possibly between components of a composite trait. PMID:24482837

Spatially-resolved studies on the role of defects and boundaries in electronic behavior of 2D materials

NASA Astrophysics Data System (ADS)

Hus, Saban M.; Li, An-Ping

2017-08-01

Two-dimensional (2D) materials are intrinsically heterogeneous. Both localized defects, such as vacancies and dopants, and mesoscopic boundaries, such as surfaces and interfaces, give rise to compositional or structural heterogeneities. The presence of defects and boundaries can break lattice symmetry, modify the energy landscape, and create quantum confinement, leading to fascinating electronic properties different from the ;ideal; 2D sheets. This review summarizes recent progress in understanding the roles of defects and boundaries in electronic, magnetic, thermoelectric, and transport properties of 2D layered materials. The focus is on the understanding of correlation of atomic-scale structural information with electronic functions by interrogating heterogeneities individually. The materials concerned are graphene, transition metal dichalcogenides (TMDs), hexagonal boron nitride (hBN), and topological insulators (TIs). The experimental investigations benefit from new methodologies and techniques in scanning tunneling microscopy (STM), including spin-polarized STM, scanning tunneling potentiometry (STP), scanning tunneling thermopower microscopy, and multi-probe STM. The experimental effort is complemented by the computational and theoretical approaches, capable of discriminating between closely competing states and achieving the length scales necessary to bridge across features such as local defects and complex heterostructures. The goal is to provide a general view of current understanding and challenges in studying the heterogeneities in 2D materials and to evaluate the potential of controlling and exploiting these heterogeneities for novel functionalities and electron devices.

Shock recovery analogs and the origin of mesosiderites. [Abstract only

NASA Technical Reports Server (NTRS)

Rowan, L. R.

1994-01-01

The origin of mesosiderites, which consist of approximately equal-weight proportions of Fe-Ni metal and silicates (gabbros, basalts, orthopyroxenites, dunites), remains an interesting and complex problem in meteoritics. There is general agreement that multiple impact events were probably involved in the formation of these brecciated stony-iron meteorites, but given the heterogeneity of mesosiderites, additional processes have been invoked to explain the unique and intricate textural and compositional makeup of mesosiderites. We conducted a series of shock recovery experiments to test the impact event(s) scenario. The results indicated significant similarities between the shocked analogs and many mesosiderites. We have compared our analogs with a suite of thin sections of Barea mesosiderite. I have conducted a series of flash heating experiments in which equal-weight proportions of gabbro and stainless steel (SS304) powders were compressed into small charges and heated under reducing conditions for short times. These experiments were used to bracket localized, peak postshock temperatures in our analog shots and to compare the mixing relations between the silicate and metal. The shock recovery experiments used porous metal-silicate powder starting mixtures, therefore our experiments are most analogous to an impact scenario where the target is an asteroidal regolith surface composed of a loose mixture of Fe-Ni metal and heterogeneous silicates. Analog experiments may really describe a secondary impact process similar to the late-stage, localized impact melting event. This leaves one of the crucial questions about mesosiderite genesis unanswered, namely what is the source of the Fe-Ni metal that is so intimately distributed in these meteorites?

Image-guided genomics of phenotypically heterogeneous populations reveals vascular signalling during symbiotic collective cancer invasion

PubMed Central

Konen, J.; Summerbell, E.; Dwivedi, B.; Galior, K.; Hou, Y.; Rusnak, L.; Chen, A.; Saltz, J.; Zhou, W.; Boise, L. H.; Vertino, P.; Cooper, L.; Salaita, K.; Kowalski, J.; Marcus, A. I.

2017-01-01

Phenotypic heterogeneity is widely observed in cancer cell populations. Here, to probe this heterogeneity, we developed an image-guided genomics technique termed spatiotemporal genomic and cellular analysis (SaGA) that allows for precise selection and amplification of living and rare cells. SaGA was used on collectively invading 3D cancer cell packs to create purified leader and follower cell lines. The leader cell cultures are phenotypically stable and highly invasive in contrast to follower cultures, which show phenotypic plasticity over time and minimally invade in a sheet-like pattern. Genomic and molecular interrogation reveals an atypical VEGF-based vasculogenesis signalling that facilitates recruitment of follower cells but not for leader cell motility itself, which instead utilizes focal adhesion kinase-fibronectin signalling. While leader cells provide an escape mechanism for followers, follower cells in turn provide leaders with increased growth and survival. These data support a symbiotic model of collective invasion where phenotypically distinct cell types cooperate to promote their escape. PMID:28497793

Direct observation of spatially heterogeneous single-layer graphene oxide reduction kinetics.

PubMed

McDonald, Matthew P; Eltom, Ahmed; Vietmeyer, Felix; Thapa, Janak; Morozov, Yurii V; Sokolov, Denis A; Hodak, Jose H; Vinodgopal, Kizhanipuram; Kamat, Prashant V; Kuno, Masaru

2013-01-01

Graphene oxide (GO) is an important precursor in the production of chemically derived graphene. During reduction, GO's electrical conductivity and band gap change gradually. Doping and chemical functionalization are also possible, illustrating GO's immense potential in creating functional devices through control of its local hybridization. Here we show that laser-induced photolysis controllably reduces individual single-layer GO sheets. The reaction can be followed in real time through sizable decreases in GO's photoluminescence efficiency along with spectral blueshifts. As-produced reduced graphene oxide (rGO) sheets undergo additional photolysis, characterized by dramatic emission enhancements and spectral redshifts. Both GO's reduction and subsequent conversion to photobrightened rGO are captured through movies of their photoluminescence kinetics. Rate maps illustrate sizable spatial and temporal heterogeneities in sp(2) domain growth and reveal how reduction "flows" across GO and rGO sheets. The observed heterogeneous reduction kinetics provides mechanistic insight into GO's conversion to chemically derived graphene and highlights opportunities for overcoming its dynamic, chemical disorder.

Uncovering hidden heterogeneity: Geo-statistical models illuminate the fine scale effects of boating infrastructure on sediment characteristics and contaminants.

PubMed

Hedge, L H; Dafforn, K A; Simpson, S L; Johnston, E L

2017-06-30

Infrastructure associated with coastal communities is likely to not only directly displace natural systems, but also leave environmental footprints' that stretch over multiple scales. Some coastal infrastructure will, there- fore, generate a hidden layer of habitat heterogeneity in sediment systems that is not immediately observable in classical impact assessment frameworks. We examine the hidden heterogeneity associated with one of the most ubiquitous coastal modifications; dense swing moorings fields. Using a model based geo-statistical framework we highlight the variation in sedimentology throughout mooring fields and reference locations. Moorings were correlated with patches of sediment with larger particle sizes, and associated metal(loid) concentrations in these patches were depressed. Our work highlights two important ideas i) mooring fields create a mosaic of habitat in which contamination decreases and grain sizes increase close to moorings, and ii) model- based frameworks provide an information rich, easy-to-interpret way to communicate complex analyses to stakeholders. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Single-cell lineage tracking analysis reveals that an established cell line comprises putative cancer stem cells and their heterogeneous progeny

PubMed Central

Sato, Sachiko; Rancourt, Ann; Sato, Yukiko; Satoh, Masahiko S.

2016-01-01

Mammalian cell culture has been used in many biological studies on the assumption that a cell line comprises putatively homogeneous clonal cells, thereby sharing similar phenotypic features. This fundamental assumption has not yet been fully tested; therefore, we developed a method for the chronological analysis of individual HeLa cells. The analysis was performed by live cell imaging, tracking of every single cell recorded on imaging videos, and determining the fates of individual cells. We found that cell fate varied significantly, indicating that, in contrast to the assumption, the HeLa cell line is composed of highly heterogeneous cells. Furthermore, our results reveal that only a limited number of cells are immortal and renew themselves, giving rise to the remaining cells. These cells have reduced reproductive ability, creating a functionally heterogeneous cell population. Hence, the HeLa cell line is maintained by the limited number of immortal cells, which could be putative cancer stem cells. PMID:27003384

Microchip-Based Single-Cell Functional Proteomics for Biomedical Applications

PubMed Central

Lu, Yao; Yang, Liu; Wei, Wei; Shi, Qihui

2017-01-01

Cellular heterogeneity has been widely recognized but only recently have single cell tools become available that allow characterizing heterogeneity at the genomic and proteomic levels. We review the technological advances in microchip-based toolkits for single-cell functional proteomics. Each of these tools has distinct advantages and limitations, and a few have advanced toward being applied to address biological or clinical problems that fail to be addressed by traditional population-based methods. High-throughput single-cell proteomic assays generate high-dimensional data sets that contain new information and thus require developing new analytical framework to extract new biology. In this review article, we highlight a few biological and clinical applications in which the microchip-based single-cell proteomic tools provide unique advantages. The examples include resolving functional heterogeneity and dynamics of immune cells, dissecting cell-cell interaction by creating well-contolled on-chip microenvironment, capturing high-resolution snapshots of immune system functions in patients for better immunotherapy and elucidating phosphoprotein signaling networks in cancer cells for guiding effective molecularly targeted therapies. PMID:28280819

Climate forcing and infectious disease transmission in urban landscapes: integrating demographic and socioeconomic heterogeneity.

PubMed

Santos-Vega, Mauricio; Martinez, Pamela P; Pascual, Mercedes

2016-10-01

Urbanization and climate change are the two major environmental challenges of the 21st century. The dramatic expansion of cities around the world creates new conditions for the spread, surveillance, and control of infectious diseases. In particular, urban growth generates pronounced spatial heterogeneity within cities, which can modulate the effect of climate factors at local spatial scales in large urban environments. Importantly, the interaction between environmental forcing and socioeconomic heterogeneity at local scales remains an open area in infectious disease dynamics, especially for urban landscapes of the developing world. A quantitative and conceptual framework on urban health with a focus on infectious diseases would benefit from integrating aspects of climate forcing, population density, and level of wealth. In this paper, we review what is known about these drivers acting independently and jointly on urban infectious diseases; we then outline elements that are missing and would contribute to building such a framework. © 2016 New York Academy of Sciences.

Hierarchical Nanoporous Gold-Platinum with Heterogeneous Interfaces for Methanol Electrooxidation

PubMed Central

Xiao, Shuang; Xiao, Fei; Hu, Yuan; Yuan, Songliu; Wang, Shuai; Qian, Lihua; Liu, Yunqi

2014-01-01

The electrocatalysts utilized as the prospective electrodes in fuel cells and high efficient energy conversion devices require both the interconnected channels for efficient electrolyte transportation and the superior catalytic activity with long service life. In this work, nanoporous gold with the rigid skeletons in three dimensions is partially decorated by porous platinum shell containing nanoscale interstitials, aiming to create the heterogeneous gold-platinum interfaces and facilitate the electrolyte transportation as well. In comparison with no catalytic activity of bare nanoporous gold, the catalytic activity of hierarchical nanoporous gold-platinum towards electrochemical oxidation of methanol increases with the loading level of platinum shells, resulting in the highest electrochemical area of 70.4 m2·g−1 after the normalization by the mass of platinum. Heterogeneous gold-platinum interfaces affect the tolerance of the absorbed intermediate species because of the oxidization by the oxygenated species absorbed on the gold surface and the enhanced ion transportation within the porous platinum shell. PMID:24621809

Advection by ocean currents modifies phytoplankton size structure.

PubMed

Font-Muñoz, Joan S; Jordi, Antoni; Tuval, Idan; Arrieta, Jorge; Anglès, Sílvia; Basterretxea, Gotzon

2017-05-01

Advection by ocean currents modifies phytoplankton size structure at small scales (1-10 cm) by aggregating cells in different regions of the flow depending on their size. This effect is caused by the inertia of the cells relative to the displaced fluid. It is considered that, at larger scales (greater than or equal to 1 km), biological processes regulate the heterogeneity in size structure. Here, we provide observational evidence of heterogeneity in phytoplankton size structure driven by ocean currents at relatively large scales (1-10 km). Our results reveal changes in the phytoplankton size distribution associated with the coastal circulation patterns. A numerical model that incorporates the inertial properties of phytoplankton confirms the role of advection on the distribution of phytoplankton according to their size except in areas with enhanced nutrient inputs where phytoplankton dynamics is ruled by other processes. The observed preferential concentration mechanism has important ecological consequences that range from the phytoplankton level to the whole ecosystem. © 2017 The Author(s).

LDRD final report : leveraging multi-way linkages on heterogeneous data.

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

Dunlavy, Daniel M.; Kolda, Tamara Gibson

2010-09-01

This report is a summary of the accomplishments of the 'Leveraging Multi-way Linkages on Heterogeneous Data' which ran from FY08 through FY10. The goal was to investigate scalable and robust methods for multi-way data analysis. We developed a new optimization-based method called CPOPT for fitting a particular type of tensor factorization to data; CPOPT was compared against existing methods and found to be more accurate than any faster method and faster than any equally accurate method. We extended this method to computing tensor factorizations for problems with incomplete data; our results show that you can recover scientifically meaningfully factorizations withmore » large amounts of missing data (50% or more). The project has involved 5 members of the technical staff, 2 postdocs, and 1 summer intern. It has resulted in a total of 13 publications, 2 software releases, and over 30 presentations. Several follow-on projects have already begun, with more potential projects in development.« less

Identifying Atomic Scale Structure in Undoped/Doped Semicrystalline P3HT Using Inelastic Neutron Scattering

DOE PAGES

Harrelson, Thomas F.; Cheng, Yongqiang Q.; Li, Jun; ...

2017-03-07

The greatest advantage of organic materials is the ability to synthetically tune desired properties. However, structural heterogeneity often obfuscates the relationship between chemical structure and functional properties. Inelastic neutron scattering (INS) is sensitive to both local structure and chemical environment and provides atomic level details that cannot be obtained through other spectroscopic or diffraction methods. INS data are composed of a density of vibrational states with no selection rules, which means that every structural configuration is equally weighted in the spectrum. This allows the INS spectrum to be quantitatively decomposed into different structural motifs. Here in this paper we presentmore » INS measurements of the semiconducting polymer P3HT doped with F4TCNQ supported by density functional theory calculations to identify two dominant families of undoped crystalline structures and one dominant doped structural motif, in spite of considerable heterogeneity. The differences between the undoped and doped structures indicate that P3HT side chains flatten upon doping.« less

Future Directions in Painful Knee Osteoarthritis: Harnessing Complexity in a Heterogeneous Population

PubMed Central

George, Steven Z.; Maluf, Katrina S.; Stevens-Lapsley, Jennifer E.

2014-01-01

This perspective article proposes a conceptual model for the pain experience for individuals diagnosed with knee osteoarthritis (OA). Pain in knee OA is likely a heterogeneous, multifactorial phenomenon that involves not only the OA disease process but also elements specific to patient psychology and pain neurophysiology. The relevant contributions to the pain experience for any individual patient remain difficult, if not impossible, to definitively determine, and the rationale for many clinical treatment decisions arises primarily from a mechanistic understanding of OA pathophysiology. The Osteoarthritis Research Society International (OARSI) recently identified “phenotyping” of OA pain as a research priority to “better target pain therapies to individual patients.” This perspective article proposes that contributions from 3 domains—knee pathology, psychological distress, and pain neurophysiology—should be considered equally important in future efforts to understand pain phenotypes in knee OA. Ultimately, characterization of pain phenotypes may aid in the understanding of the pain experience and the development of interventions specific to pain for individual patients. PMID:24179141

Equalization filters for multiple-channel electromyogram arrays

PubMed Central

Clancy, Edward A.; Xia, Hongfang; Christie, Anita; Kamen, Gary

2007-01-01

Multiple channels of electromyogram activity are frequently transduced via electrodes, then combined electronically to form one electrophysiologic recording, e.g. bipolar, linear double difference and Laplacian montages. For high quality recordings, precise gain and frequency response matching of the individual electrode potentials is achieved in hardware (e.g., an instrumentation amplifier for bipolar recordings). This technique works well when the number of derived signals is small and the montages are pre-determined. However, for array electrodes employing a variety of montages, hardware channel matching can be expensive and tedious, and limits the number of derived signals monitored. This report describes a method for channel matching based on the concept of equalization filters. Monopolar potentials are recorded from each site without precise hardware matching. During a calibration phase, a time-varying linear chirp voltage is applied simultaneously to each site and recorded. Based on the calibration recording, each monopolar channel is digitally filtered to “correct” for (equalize) differences in the individual channels, and then any derived montages subsequently created. In a hardware demonstration system, the common mode rejection ratio (at 60 Hz) of bipolar montages improved from 35.2 ± 5.0 dB (prior to channel equalization) to 69.0 ± 5.0 dB (after equalization). PMID:17614134

Gender (in)equality among employees in elder care: implications for health.

PubMed

Elwér, Sofia; Aléx, Lena; Hammarström, Anne

2012-01-04

Gendered practices of working life create gender inequalities through horizontal and vertical gender segregation in work, which may lead to inequalities in health between women and men. Gender equality could therefore be a key element of health equity in working life. Our aim was to analyze what gender (in)equality means for the employees at a woman-dominated workplace and discuss possible implications for health experiences. All caregiving staff at two workplaces in elder care within a municipality in the north of Sweden were invited to participate in the study. Forty-five employees participated, 38 women and 7 men. Seven focus group discussions were performed and led by a moderator. Qualitative content analysis was used to analyze the focus groups. We identified two themes. "Advocating gender equality in principle" showed how gender (in)equality was seen as a structural issue not connected to the individual health experiences. "Justifying inequality with individualism" showed how the caregivers focused on personalities and interests as a justification of gender inequalities in work division. The justification of gender inequality resulted in a gendered work division which may be related to health inequalities between women and men. Gender inequalities in work division were primarily understood in terms of personality and interests and not in terms of gender. The health experience of the participants was affected by gender (in)equality in terms of a gendered work division. However, the participants did not see the gendered work division as a gender equality issue. Gender perspectives are needed to improve the health of the employees at the workplaces through shifting from individual to structural solutions. A healthy-setting approach considering gender relations is needed to achieve gender equality and fairness in health status between women and men.

Gender (in)equality among employees in elder care: implications for health

PubMed Central

2012-01-01

Introduction Gendered practices of working life create gender inequalities through horizontal and vertical gender segregation in work, which may lead to inequalities in health between women and men. Gender equality could therefore be a key element of health equity in working life. Our aim was to analyze what gender (in)equality means for the employees at a woman-dominated workplace and discuss possible implications for health experiences. Methods All caregiving staff at two workplaces in elder care within a municipality in the north of Sweden were invited to participate in the study. Forty-five employees participated, 38 women and 7 men. Seven focus group discussions were performed and led by a moderator. Qualitative content analysis was used to analyze the focus groups. Results We identified two themes. "Advocating gender equality in principle" showed how gender (in)equality was seen as a structural issue not connected to the individual health experiences. "Justifying inequality with individualism" showed how the caregivers focused on personalities and interests as a justification of gender inequalities in work division. The justification of gender inequality resulted in a gendered work division which may be related to health inequalities between women and men. Gender inequalities in work division were primarily understood in terms of personality and interests and not in terms of gender. Conclusion The health experience of the participants was affected by gender (in)equality in terms of a gendered work division. However, the participants did not see the gendered work division as a gender equality issue. Gender perspectives are needed to improve the health of the employees at the workplaces through shifting from individual to structural solutions. A healthy-setting approach considering gender relations is needed to achieve gender equality and fairness in health status between women and men. PMID:22217427

Consumer choice among Mutual Healthcare Purchasers: a feasible option for China?

PubMed

Xu, Weiwei; van de Ven, Wynand P M M

2013-11-01

In its 2009 blue print of healthcare reform, the Chinese government aimed to create a competitive health insurance market in order to increase efficiency in the health insurance sector. A major advantage of a competitive health insurance market is that insurers are stimulated to act as well-motivated prudent purchasers of healthcare on behalf of their enrolees, and that consumers can choose among these purchasers. To emphasize the insurers' role of purchasers of care we denote them, as well as other entities that can fulfil this role (e.g. fundholding community health centres), as 'Mutual Healthcare Purchasers' (MHPs). As feasible proposals for creating competition in China's health insurance sector have yet to be made, we suggest two potential approaches to create competition among MHPs: (1) separating finance and operation of social health insurance and allowing consumer choice among operators of social health insurance schemes; (2) allowing consumer choice among fund-holding community health centres. Although the benefits of competition are widely accepted in China, the problematic consequences of a free competitive health insurance market - especially in relation to affordability and accessibility - are generally neglected. To solve the problems of lack of affordability and inaccessibility that would occur in the case of unregulated competition among MHPs, at least the following regulations are proposed to the Chinese policy makers: a 'standard benefit package' for basic health insurance, a 'risk-equalization scheme', and 'open enrolment'. Potential obstacles for implementing a risk equalization scheme are examined based on theoretical arguments and international experiences. We conclude that allowing consumer choice among MHPs and implementing a risk equalization scheme in China is politically and technically complex. Therefore, the Chinese government should prepare carefully for a market-oriented reform in its healthcare sector and adopt a strategic approach in the implementation procedure. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Waste management: how reducing partiality can promote efficient resource allocation.

PubMed

Choshen-Hillel, Shoham; Shaw, Alex; Caruso, Eugene M

2015-08-01

Two central principles that guide resource-allocation decisions are equity (providing equal pay for equal work) and efficiency (not wasting resources). When these two principles conflict with one another, people will often waste resources to avoid inequity. We suggest that people wish to avoid inequity not because they find it inherently unfair, but because they want to avoid the appearance of partiality associated with it. We explore one way to reduce waste by reducing the perceived partiality of inequitable allocations. Specifically, we hypothesize that people will be more likely to favor an efficient (albeit inequitable) allocation if it puts them in a disadvantaged position than if it puts others in a disadvantaged position. To test this hypothesis, we asked participants to choose between giving some extra resource to one person (thereby creating inequity between this person and equally deserving others) and not giving the resource to anyone (thereby wasting the resource). Six studies, using realistic scenarios and behavioral paradigms, provide robust evidence for a self-disadvantaging effect: Allocators were consistently more likely to create inequity to avoid wasting resources when the resulting inequity would put them at a relative disadvantage than when it would put others at a relative disadvantage. We further find that this self-disadvantaging effect is a direct result of people's concern about appearing partial. Our findings suggest the importance of impartiality even in distributive justice, thereby bridging a gap between the distributive and procedural justice literatures. (c) 2015 APA, all rights reserved.

Biofilm three-dimensional architecture influences in situ pH distribution pattern on the human enamel surface

PubMed Central

Xiao, Jin; Hara, Anderson T; Kim, Dongyeop; Zero, Domenick T; Koo, Hyun; Hwang, Geelsu

2017-01-01

To investigate how the biofilm three-dimensional (3D) architecture influences in situ pH distribution patterns on the enamel surface. Biofilms were formed on human tooth enamel in the presence of 1% sucrose or 0.5% glucose plus 0.5% fructose. At specific time points, biofilms were exposed to a neutral pH buffer to mimic the buffering of saliva and subsequently pulsed with 1% glucose to induce re-acidification. Simultaneous 3D pH mapping and architecture of intact biofilms was performed using two-photon confocal microscopy. The enamel surface and mineral content characteristics were examined successively via optical profilometry and microradiography analyses. Sucrose-mediated biofilm formation created spatial heterogeneities manifested by complex networks of bacterial clusters (microcolonies). Acidic regions (pH<5.5) were found only in the interior of microcolonies, which impedes rapid neutralization (taking more than 120 min for neutralization). Glucose exposure rapidly re-created the acidic niches, indicating formation of diffusion barriers associated with microcolonies structure. Enamel demineralization (white spots), rougher surface, deeper lesion and more mineral loss appeared to be associated with the localization of these bacterial clusters at the biofilm-enamel interface. Similar 3D architecture was observed in plaque-biofilms formed in vivo in the presence of sucrose. The formation of complex 3D architectures creates spatially heterogeneous acidic microenvironments in close proximity of enamel surface, which might correlate with the localized pattern of the onset of carious lesions (white spot like) on teeth. PMID:28452377

Respiratory health equality in the United States. The American thoracic society perspective.

PubMed

Celedón, Juan C; Roman, Jesse; Schraufnagel, Dean E; Thomas, Alvin; Samet, Jonathan

2014-05-01

Because the frequency of major risk factors for respiratory diseases (e.g., tobacco use) differs across demographic groups (defined by socioeconomic status, race/ethnicity, sexual orientation, health care access, occupation, or other characteristics), health disparities are commonly encountered in pediatric and adult pulmonary, critical care, and sleep medicine. As part of its policy on respiratory health disparities, the American Thoracic Society (ATS) Executive Committee created a Health Equality Subcommittee of the Health Policy Committee, with an initial mandate of defining respiratory health equality and, as a subsequent task, providing recommendations to the ATS leadership as to how our society may help attain such equality in the United States. After receiving input from the ATS assemblies and committees, the subcommittee developed this document on respiratory health equality. This document defines respiratory health disparities and respiratory health equality, and expands on a recent ATS and European Respiratory Society policy statement on disparities in respiratory health. Attainment of respiratory health equality requires the ending of respiratory health disparities, which can be achieved only through multidisciplinary efforts to eliminate detrimental environmental exposures while promoting a healthy lifestyle, implementing all components of high-quality health care (prevention, screening, diagnosis, and treatment), and conducting research that will lead to better prevention and management of respiratory diseases for everyone. The ATS recognizes that such efforts must include all stakeholders: members of society at large, governmental and nongovernmental organizations, and other professional societies. The ATS urges all of its members and those of sister societies to work to achieve this laudable goal.

Respiratory Health Equality in the United States. The American Thoracic Society Perspective

PubMed Central

Roman, Jesse; Schraufnagel, Dean E.; Thomas, Alvin; Samet, Jonathan

2014-01-01

Because the frequency of major risk factors for respiratory diseases (e.g., tobacco use) differs across demographic groups (defined by socioeconomic status, race/ethnicity, sexual orientation, health care access, occupation, or other characteristics), health disparities are commonly encountered in pediatric and adult pulmonary, critical care, and sleep medicine. As part of its policy on respiratory health disparities, the American Thoracic Society (ATS) Executive Committee created a Health Equality Subcommittee of the Health Policy Committee, with an initial mandate of defining respiratory health equality and, as a subsequent task, providing recommendations to the ATS leadership as to how our society may help attain such equality in the United States. After receiving input from the ATS assemblies and committees, the subcommittee developed this document on respiratory health equality. This document defines respiratory health disparities and respiratory health equality, and expands on a recent ATS and European Respiratory Society policy statement on disparities in respiratory health. Attainment of respiratory health equality requires the ending of respiratory health disparities, which can be achieved only through multidisciplinary efforts to eliminate detrimental environmental exposures while promoting a healthy lifestyle, implementing all components of high-quality health care (prevention, screening, diagnosis, and treatment), and conducting research that will lead to better prevention and management of respiratory diseases for everyone. The ATS recognizes that such efforts must include all stakeholders: members of society at large, governmental and nongovernmental organizations, and other professional societies. The ATS urges all of its members and those of sister societies to work to achieve this laudable goal. PMID:24625275

Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

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

Hernandez, Andrew M., E-mail: amhern@ucdavis.edu; Seibert, J. Anthony; Boone, John M.

2015-11-15

Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fitmore » to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width in the superior and inferior directions, resulted in a 37.3% and a −26.6% change in the pDgN{sub hetero} coefficient, respectively, relative to the centered distribution for the Mo–Mo spectrum. Lateral displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width, resulted in a 1.5% change in the pDgN{sub hetero} coefficient relative to the centered distribution for the W–Rh spectrum. Conclusions: Introducing bCT-derived heterogeneous glandular distributions into mammography phantom design resulted in decreased glandular dose relative to the widely used homogeneous assumption. A homogeneous distribution overestimates the amount of glandular tissue near the entrant surface of the breast, where dose deposition is exponentially higher. While these findings are based on clinically measured distributions of glandular tissue using a large cohort of women, future work is required to improve the classification of glandular distributions based on breast size and overall glandular fraction.« less

Shrinking cities examined from a shrinking scale – the impact of household and neighborhood heterogeneity on changes in material and energy consumption, ecosystem services and environmental impact

EPA Science Inventory

Urban populations continue to increase globally and cities have become the dominant human habitat. However, the growth of cities is not universal. Shrinking cities face decreased income, reduced property values, and decreased tax revenue. Fewer people per unit area creates ineffi...

Microsite controls on tree seedling establishment in conifer forest canopy gaps

Treesearch

Andrew N. Gray; Thomas A. Spies

1997-01-01

Tree seedling establishment and growth were studied in experimental canopy gaps to assess the effect of heterogeneity of regeneration microsites within and among gaps in mature conifer forests. Seedlings were studied for two years in closed-canopy areas and in recently created gaps ranging in size from 40 to 2000 m2 in four stands of mature (90-...

Canopy gap size influences niche partitioning of the ground-layer plant community in a northern temperate forest

Treesearch

Christel C. Kern; Rebecca A. Montgomery; Peter B. Reich; Terry F. Strong

2013-01-01

The Gap Partitioning Hypothesis (GPH) posits that gaps create heterogeneity in resources crucial for tree regeneration in closed-canopy forests, allowing trees with contrasting strategies to coexist along resource gradients. Few studies have examined gap partitioning of temperate, ground-layer vascular plants. We used a ground-layer plant community of a temperate...

Variable-density thinning in coast redwood: a comparison of marking strategies to attain stand variability

Treesearch

Kevin L. O' Hara; Lathrop P. Leonard; Christopher R. Keyes

2012-01-01

Variable-density thinning (VDT) is an emerging thinning method that attempts to enhance stand structural heterogeneity by deliberately thinning at different intensities throughout a stand. VDT may create stands with dense areas, open areas, and other areas that may be intermediate in density. Subsequent stand development forms a more varied structure than is...

Big Data: An Opportunity for Collaboration with Computer Scientists on Data-Driven Science

NASA Astrophysics Data System (ADS)

Baru, C.

2014-12-01

Big data technologies are evolving rapidly, driven by the need to manage ever increasing amounts of historical data; process relentless streams of human and machine-generated data; and integrate data of heterogeneous structure from extremely heterogeneous sources of information. Big data is inherently an application-driven problem. Developing the right technologies requires an understanding of the applications domain. Though, an intriguing aspect of this phenomenon is that the availability of the data itself enables new applications not previously conceived of! In this talk, we will discuss how the big data phenomenon creates an imperative for collaboration among domain scientists (in this case, geoscientists) and computer scientists. Domain scientists provide the application requirements as well as insights about the data involved, while computer scientists help assess whether problems can be solved with currently available technologies or require adaptaion of existing technologies and/or development of new technologies. The synergy can create vibrant collaborations potentially leading to new science insights as well as development of new data technologies and systems. The area of interface between geosciences and computer science, also referred to as geoinformatics is, we believe, a fertile area for interdisciplinary research.

Interactions of lectins with plasma membrane glycoproteins of the Ehrlich ascites carcinoma cell.

PubMed

Nachbar, M S; Oppenheim, J D; Aull, F

1976-02-06

Several aspects of the interaction of various lectins with the surface of Ehrlich ascites carcinoma cells are described. The order of agglutinating activity for various lectins is Ricinus communis greater than wheat germ greater than or equal to concanavalin A greater than or equal to soybean greater than Limulus polyphemus. No agglutination was noted for Ulex europaeus. Using 125I-labeled lectins it was determined that there are 1.6 and 7 times as many Ricinus communis lectin binding sites for concanavalin A and soybean lectins. Sodium deoxycholate-solubilized plasma membrane material was subjected to lectin affinity chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The lectin receptors of the plasma membrane appeared to be heterogeneous and some qualitative differences could be discerned among the electrophoretically analyzed material, which bound to and was specifically eluted from the various lectin affinity columns. The characteristics of elution of bound material from individual lectin columns indicated secondary hydrophobic interactions between concanavalin A or wheat germ agglutinin and their respective lectin receptor molecules.

Uniform enhancement of optical micro-angiography images using Rayleigh contrast-limited adaptive histogram equalization.

PubMed

Yousefi, Siavash; Qin, Jia; Zhi, Zhongwei; Wang, Ruikang K

2013-02-01

Optical microangiography is an imaging technology that is capable of providing detailed functional blood flow maps within microcirculatory tissue beds in vivo. Some practical issues however exist when displaying and quantifying the microcirculation that perfuses the scanned tissue volume. These issues include: (I) Probing light is subject to specular reflection when it shines onto sample. The unevenness of the tissue surface makes the light energy entering the tissue not uniform over the entire scanned tissue volume. (II) The biological tissue is heterogeneous in nature, meaning the scattering and absorption properties of tissue would attenuate the probe beam. These physical limitations can result in local contrast degradation and non-uniform micro-angiogram images. In this paper, we propose a post-processing method that uses Rayleigh contrast-limited adaptive histogram equalization to increase the contrast and improve the overall appearance and uniformity of optical micro-angiograms without saturating the vessel intensity and changing the physical meaning of the micro-angiograms. The qualitative and quantitative performance of the proposed method is compared with those of common histogram equalization and contrast enhancement methods. We demonstrate that the proposed method outperforms other existing approaches. The proposed method is not limited to optical microangiography and can be used in other image modalities such as photo-acoustic tomography and scanning laser confocal microscopy.

Reconnaissance blind multi-chess: an experimentation platform for ISR sensor fusion and resource management

NASA Astrophysics Data System (ADS)

Newman, Andrew J.; Richardson, Casey L.; Kain, Sean M.; Stankiewicz, Paul G.; Guseman, Paul R.; Schreurs, Blake A.; Dunne, Jeffrey A.

2016-05-01

This paper introduces the game of reconnaissance blind multi-chess (RBMC) as a paradigm and test bed for understanding and experimenting with autonomous decision making under uncertainty and in particular managing a network of heterogeneous Intelligence, Surveillance and Reconnaissance (ISR) sensors to maintain situational awareness informing tactical and strategic decision making. The intent is for RBMC to serve as a common reference or challenge problem in fusion and resource management of heterogeneous sensor ensembles across diverse mission areas. We have defined a basic rule set and a framework for creating more complex versions, developed a web-based software realization to serve as an experimentation platform, and developed some initial machine intelligence approaches to playing it.

An Advice Mechanism for Heterogeneous Robot Teams

NASA Astrophysics Data System (ADS)

Daniluk, Steven

The use of reinforcement learning for robot teams has enabled complex tasks to be performed, but at the cost of requiring a large amount of exploration. Exchanging information between robots in the form of advice is one method to accelerate performance improvements. This thesis presents an advice mechanism for robot teams that utilizes advice from heterogeneous advisers via a method guaranteeing convergence to an optimal policy. The presented mechanism has the capability to use multiple advisers at each time step, and decide when advice should be requested and accepted, such that the use of advice decreases over time. Additionally, collective collaborative, and cooperative behavioural algorithms are integrated into a robot team architecture, to create a new framework that provides fault tolerance and modularity for robot teams.

Subpopulation-proteomics in prokaryotic populations.

PubMed

Jahn, Michael; Seifert, Jana; von Bergen, Martin; Schmid, Andreas; Bühler, Bruno; Müller, Susann

2013-02-01

Clonal microbial cells do not behave in an identical manner and form subpopulations during cultivation. Besides varying micro-environmental conditions, cell inherent features like cell cycle dependent localization and concentration of regulatory proteins as well as epigenetic properties are well accepted mechanisms creating cell heterogeneity. Another suspected reason is molecular noise on the transcriptional and translational level. A promising tool to unravel reasons for cell heterogeneity is the combination of cell sorting and subpopulation proteomics. This review summarizes recent developments in prokaryotic single-cell analytics and provides a workflow for selection of single cells, low cell number mass spectrometry, and proteomics evaluation. This approach is useful for understanding the dependency of individual cell decisions on inherent protein profiles. Copyright © 2012 Elsevier Ltd. All rights reserved.

Heterogeneous fuel for hybrid rocket

NASA Technical Reports Server (NTRS)

Stickler, David B. (Inventor)

1996-01-01

Heterogeneous fuel compositions suitable for use in hybrid rocket engines and solid-fuel ramjet engines, The compositions include mixtures of a continuous phase, which forms a solid matrix, and a dispersed phase permanently distributed therein. The dispersed phase or the matrix vaporizes (or melts) and disperses into the gas flow much more rapidly than the other, creating depressions, voids and bumps within and on the surface of the remaining bulk material that continuously roughen its surface, This effect substantially enhances heat transfer from the combusting gas flow to the fuel surface, producing a correspondingly high burning rate, The dispersed phase may include solid particles, entrained liquid droplets, or gas-phase voids having dimensions roughly similar to the displacement scale height of the gas-flow boundary layer generated during combustion.

Comparison of TG-43 and TG-186 in breast irradiation using a low energy electronic brachytherapy source.

PubMed

White, Shane A; Landry, Guillaume; Fonseca, Gabriel Paiva; Holt, Randy; Rusch, Thomas; Beaulieu, Luc; Verhaegen, Frank; Reniers, Brigitte

2014-06-01

The recently updated guidelines for dosimetry in brachytherapy in TG-186 have recommended the use of model-based dosimetry calculations as a replacement for TG-43. TG-186 highlights shortcomings in the water-based approach in TG-43, particularly for low energy brachytherapy sources. The Xoft Axxent is a low energy (<50 kV) brachytherapy system used in accelerated partial breast irradiation (APBI). Breast tissue is a heterogeneous tissue in terms of density and composition. Dosimetric calculations of seven APBI patients treated with Axxent were made using a model-based Monte Carlo platform for a number of tissue models and dose reporting methods and compared to TG-43 based plans. A model of the Axxent source, the S700, was created and validated against experimental data. CT scans of the patients were used to create realistic multi-tissue/heterogeneous models with breast tissue segmented using a published technique. Alternative water models were used to isolate the influence of tissue heterogeneity and backscatter on the dose distribution. Dose calculations were performed using Geant4 according to the original treatment parameters. The effect of the Axxent balloon applicator used in APBI which could not be modeled in the CT-based model, was modeled using a novel technique that utilizes CAD-based geometries. These techniques were validated experimentally. Results were calculated using two dose reporting methods, dose to water (Dw,m) and dose to medium (Dm,m), for the heterogeneous simulations. All results were compared against TG-43-based dose distributions and evaluated using dose ratio maps and DVH metrics. Changes in skin and PTV dose were highlighted. All simulated heterogeneous models showed a reduced dose to the DVH metrics that is dependent on the method of dose reporting and patient geometry. Based on a prescription dose of 34 Gy, the average D90 to PTV was reduced by between ~4% and ~40%, depending on the scoring method, compared to the TG-43 result. Peak skin dose is also reduced by 10%-15% due to the absence of backscatter not accounted for in TG-43. The balloon applicator also contributed to the reduced dose. Other ROIs showed a difference depending on the method of dose reporting. TG-186-based calculations produce results that are different from TG-43 for the Axxent source. The differences depend strongly on the method of dose reporting. This study highlights the importance of backscatter to peak skin dose. Tissue heterogeneities, applicator, and patient geometries demonstrate the need for a more robust dose calculation method for low energy brachytherapy sources.

Technological advances in cosmogenic neutron detectors for measuring soil water content

NASA Astrophysics Data System (ADS)

Zreda, M. G.; Schrön, M.; Köhli, M.

2017-12-01

The cosmic-ray neutron probe is used for measuring area-average soil water content at the hectometer scale. Early work showed a simple exponential decrease with distance of the instrument's sensitivity and a footprint 300 m in radius. Recent research suggested a much higher sensitivity to local neutrons and reduced footprint. We show results confirming the high sensitivity to local neutrons, describe two ways to reduce local and increase far-field effects, and propose ways of measuring neutrons at different spatial scales. Measurements with moderated detectors across a 10-m-wide creek and a 2-m-wide water tank show a decrease by 30% and 20%, respectively, of neutron intensity over water compared to that over land nearby. These results mean that the detector is sensitive to meter-scale heterogeneities of water content. This sensitivity can be reduced by rising the detector or by shielding it from local neutrons. The effect of local water distributions on the measured neutron intensity decreases with height. In the water tank experiment it disappeared almost completely at the height of 2 m, leading to the conjecture that the height roughly equal to the horizontal scale of heterogeneity would eliminate the sensitivity. This may or may not be practical. Shielding the detector below by a hydrogenous material removes a substantial fraction of the local neutrons. The shielded detector has a reduced count rate, reduced sensitivity to local neutrons and increased sensitivity to neutrons farther afield, and a larger footprint. Such a detector could be preferable to the current cosmogenic-neutron probe under heterogeneous soil water conditions. The shielding experiments also inspired the development of a local-area neutron detector. It has hydrogenous neutron shields on all sides except the bottom, substantially blocking the neutrons coming from afar, while allowing the neutrons coming directly from below. Its footprint is equal to its physical dimension when the detector is placed on the surface. Once this detector is calibrated, it can be useful in calibrating the wide-area detector, for example over stony soils that are difficult to sample physically for water content determination, and in high-resolution mapping of neutron intensity and soil moisture.

Divorce and marital equality in Orizaba, Mexico, 1915-1940.

PubMed

Swedberg, Gregory

2009-01-01

Mexico's legalization of divorce in 1917 generated tension in working-class communities such as Orizaba between traditional forms of gender relations that afforded men the right to control and discipline their wives and budding legal opportunities that provided women the opportunity to question their husbands' familial power. The state's legal reforms and its emphasis on protecting women and children were not, however intended to create equality between husbands and wives. Rather; officials believed that new laws would enable women to carry out their familial responsibilities more effectively. Nonetheless, mothers and wives were quick to understand how their ability to challenge their husbands' power overlapped with the state's mission to protect women and their children.

Opportunities and challenges in biological lignin valorization

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

Beckham, Gregg T.; Johnson, Christopher W.; Karp, Eric M.

Lignin is a primary component of lignocellulosic biomass that is an underutilized feedstock in the growing biofuels industry. Despite the fact that lignin depolymerization has long been studied, the intrinsic heterogeneity of lignin typically leads to heterogeneous streams of aromatic compounds, which in turn present significant technical challenges when attempting to produce lignin-derived chemicals where purity is often a concern. In Nature, microorganisms often encounter this same problem during biomass turnover wherein powerful oxidative enzymes produce heterogeneous slates of aromatics compounds. Some microbes have evolved metabolic pathways to convert these aromatic species via ‘upper pathways’ into central intermediates, which canmore » then be funneled through ‘lower pathways’ into central carbon metabolism in a process we dubbed ‘biological funneling’. This funneling approach offers a direct, biological solution to overcome heterogeneity problems in lignin valorization for the modern biorefinery. Coupled to targeted separations and downstream chemical catalysis, this concept offers the ability to produce a wide range of molecules from lignin. This perspective describes research opportunities and challenges ahead for this new field of research, which holds significant promise towards a biorefinery concept wherein polysaccharides and lignin are treated as equally valuable feedstocks. In particular, we discuss tailoring the lignin substrate for microbial utilization, host selection for biological funneling, ligninolytic enzyme–microbe synergy, metabolic engineering, expanding substrate specificity for biological funneling, and process integration, each of which presents key challenges. Ultimately, for biological solutions to lignin valorization to be viable, multiple questions in each of these areas will need to be addressed, making biological lignin valorization a multidisciplinary, co-design problem.« less

Group search algorithm recovers effective connectivity maps for individuals in homogeneous and heterogeneous samples.

PubMed

Gates, Kathleen M; Molenaar, Peter C M

2012-10-15

At its best, connectivity mapping can offer researchers great insight into how spatially disparate regions of the human brain coordinate activity during brain processing. A recent investigation conducted by Smith and colleagues (2011) on methods for estimating connectivity maps suggested that those which attempt to ascertain the direction of influence among ROIs rarely provide reliable results. Another problem gaining increasing attention is heterogeneity in connectivity maps. Most group-level methods require that the data come from homogeneous samples, and misleading findings may arise from current methods if the connectivity maps for individuals vary across the sample (which is likely the case). The utility of maps resulting from effective connectivity on the individual or group levels is thus diminished because they do not accurately inform researchers. The present paper introduces a novel estimation technique for fMRI researchers, Group Iterative Multiple Model Estimation (GIMME), which demonstrates that using information across individuals assists in the recovery of the existence of connections among ROIs used by Smith and colleagues (2011) and the direction of the influence. Using heterogeneous in-house data, we demonstrate that GIMME offers a unique improvement over current approaches by arriving at reliable group and individual structures even when the data are highly heterogeneous across individuals comprising the group. An added benefit of GIMME is that it obtains reliable connectivity map estimates equally well using the data from resting state, block, or event-related designs. GIMME provides researchers with a powerful, flexible tool for identifying directed connectivity maps at the group and individual levels. Copyright © 2012 Elsevier Inc. All rights reserved.

Lattice Boltzmann simulation of immiscible fluid displacement in porous media: Homogeneous versus heterogeneous pore network

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

Liu, Haihu, E-mail: haihu.liu@mail.xjtu.edu.cn; James Weir Fluids Laboratory, Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ; Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801

Injection of anthropogenic carbon dioxide (CO{sub 2}) into geological formations is a promising approach to reduce greenhouse gas emissions into the atmosphere. Predicting the amount of CO{sub 2} that can be captured and its long-term storage stability in subsurface requires a fundamental understanding of multiphase displacement phenomena at the pore scale. In this paper, the lattice Boltzmann method is employed to simulate the immiscible displacement of a wetting fluid by a non-wetting one in two microfluidic flow cells, one with a homogeneous pore network and the other with a randomly heterogeneous pore network. We have identified three different displacement patterns,more » namely, stable displacement, capillary fingering, and viscous fingering, all of which are strongly dependent upon the capillary number (Ca), viscosity ratio (M), and the media heterogeneity. The non-wetting fluid saturation (S{sub nw}) is found to increase nearly linearly with logCa for each constant M. Increasing M (viscosity ratio of non-wetting fluid to wetting fluid) or decreasing the media heterogeneity can enhance the stability of the displacement process, resulting in an increase in S{sub nw}. In either pore networks, the specific interfacial length is linearly proportional to S{sub nw} during drainage with equal proportionality constant for all cases excluding those revealing considerable viscous fingering. Our numerical results confirm the previous experimental finding that the steady state specific interfacial length exhibits a linear dependence on S{sub nw} for either favorable (M ≥ 1) or unfavorable (M < 1) displacement, and the slope is slightly higher for the unfavorable displacement.« less

Effect of non-normality on test statistics for one-way independent groups designs.

PubMed

Cribbie, Robert A; Fiksenbaum, Lisa; Keselman, H J; Wilcox, Rand R

2012-02-01

The data obtained from one-way independent groups designs is typically non-normal in form and rarely equally variable across treatment populations (i.e., population variances are heterogeneous). Consequently, the classical test statistic that is used to assess statistical significance (i.e., the analysis of variance F test) typically provides invalid results (e.g., too many Type I errors, reduced power). For this reason, there has been considerable interest in finding a test statistic that is appropriate under conditions of non-normality and variance heterogeneity. Previously recommended procedures for analysing such data include the James test, the Welch test applied either to the usual least squares estimators of central tendency and variability, or the Welch test with robust estimators (i.e., trimmed means and Winsorized variances). A new statistic proposed by Krishnamoorthy, Lu, and Mathew, intended to deal with heterogeneous variances, though not non-normality, uses a parametric bootstrap procedure. In their investigation of the parametric bootstrap test, the authors examined its operating characteristics under limited conditions and did not compare it to the Welch test based on robust estimators. Thus, we investigated how the parametric bootstrap procedure and a modified parametric bootstrap procedure based on trimmed means perform relative to previously recommended procedures when data are non-normal and heterogeneous. The results indicated that the tests based on trimmed means offer the best Type I error control and power when variances are unequal and at least some of the distribution shapes are non-normal. © 2011 The British Psychological Society.

Control, Trust, and Rethinking Traditional Roles: Critical Elements in Creating a Mutually Beneficial University-School Partnership.

ERIC Educational Resources Information Center

Lewison, Mitzi; Holliday, Sue

1997-01-01

Describes a partnership between a university graduate student and the principal and teachers of a traditional elementary school who collaborated to engage in study group sessions, keep professional journals, and read and discuss research articles on writing instruction. The paper addresses issues of building trust, equalizing power, and…

The Politics, Policies and Progress of Basic Education in Sri Lanka. CREATE Pathways to Access. Research Monograph No. 38

ERIC Educational Resources Information Center

Little, Angela W.

2010-01-01

Sri Lanka is hailed internationally for her achievements in literacy, access to education and equality of educational opportunity. However, progress has not been straightforward due to the complex interactions between politics, policy formulation, and the implementation of reforms. This dynamic process has often led to contradictory outcomes. This…

The University and Race Relations.

ERIC Educational Resources Information Center

Hinderaker, Ivan

The most critical issue that the US must face is whether people of all races can work together and create a society in which equal opportunity genuinely exists for all. The racism practiced throughout the US has produced potentially destructive forces that could lead to a second civil war between outraged minority groups and the rest of society.…

Academic Freedom in Canadian Higher Education: Universities, Colleges, and Institutes Were Not Created Equal

ERIC Educational Resources Information Center

Hogan, Barry E.; Trotter, Lane D.

2013-01-01

There has been substantial discussion, research, and debate about the role of academic freedom within higher education, primarily centered on the university model. Not as well documented or understood is the issue of academic freedom within colleges and institutes in Canada. In this paper, we examine the current state of academic freedom in…

78 FR 26227 - Law Day, U.S.A., 2013

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

... are created equal; that they are endowed by their Creator with certain unalienable rights; that among... founding creed. We honor the courageous men and women who fought to bring those ageless ideals of freedom and fairness into the rule of law--from the Civil Rights Act and the Voting Rights Act to Title IX and...

Earning by Degrees: Differences in the Career Outcomes of UK Graduates

ERIC Educational Resources Information Center

de Vries, Robert

2014-01-01

Despite increasing numbers of young people going on to higher education, a university degree still confers a substantial advantage in the labour market. However, not all degrees are created equal. This report examines how graduate career outcomes differ depending on the subject they studied and the university they attended. Key findings include:…

Colorado GEAR UP Program Design and Its Effect on Student Perceptions of Postsecondary Education

ERIC Educational Resources Information Center

Mendelsberg, Scott

2012-01-01

Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) is a federal program aimed at equalizing access to higher education for low-income students. GEAR UP, created in 1998, attempts to provide information and support about higher education to students beginning no later than the seventh grade while promoting lasting…

Creating Opportunities for Mutual Affiliation: Gang Prevention and Relational-Cultural Theory in Project YES

ERIC Educational Resources Information Center

Randell, Stacy T.; Smith, Amy E.; Steinman, Bernard A.

2015-01-01

American youth do not have equal access to academic success and life achievements. In particular, low-income male students of color are disproportionately failing in school, filling prisons, and enduring the consequences of low social capital and poor investment in their futures. Unfortunately, many young people cope with poverty and life in…

Are All Judgments Created Equal? An fMRI Study of Semantic and Episodic Metamemory Predictions

ERIC Educational Resources Information Center

Reggev, Niv; Zuckerman, Maya; Maril, Anat

2011-01-01

Metamemory refers to the ability of individuals to monitor and control their own memory performance. Although little theoretical consideration of the possible differences between the monitoring of episodic and of semantic knowledge has been published, results from patient and drug studies that used the "feeling of knowing" (FOK) paradigm show a…

Community-Based English Clubs: English Practice and Social Change outside the Classroom

ERIC Educational Resources Information Center

Malu, Kathleen F.; Smedley, Bryce

2016-01-01

This article defines and provides a rationale for the creation of community-based English clubs. We offer strategies that individuals can use to create and sustain English clubs, and we suggest meeting activities that will engage members in conversations and potential community action on a range of topics such as democracy, gender equality, and…

Universal Design for Learning. Practice Perspectives--Highlighting Information on Deaf-Blindness. Number 8

ERIC Educational Resources Information Center

Hartmann, Elizabeth

2011-01-01

It is essential that children who are deaf-blind have learning experiences that improve their quality of life. Unfortunately, even when educational teams work together to create individualized education programs, these students do not always have full and equal opportunities to learn. This issue of "Practice Perspectives" describes the basics of…

The Relationship between Selected Educational Technologies and Student-Centered versus Teacher-Centered Instruction

ERIC Educational Resources Information Center

Kollmer, Michael J.

2013-01-01

Not all teachers and students have equal access to technology. This inequality of access creates an uneven instructional practice that may result in varied student learning. By and large, students have limited access to technology within the confines of the classroom. New educational technologies provide schools with an opportunity to broaden and…

Reforming Reforms: Changing Incentives in Education Finance in Vermont

ERIC Educational Resources Information Center

Schmidt, Stephen J.; Scott, Karen

2006-01-01

In 1997, Vermont passed Act 60, which reformed its education finance system to achieve greater equality of spending. The reform encouraged wealthy towns to reduce spending; it was politically unpopular and was replaced, in 2004, by Act 68. We analyze the spending incentives created by the two acts and estimate the effects the change will have on…

Empowering the Self, Creating Worlds: Lesbian and Gay Latina/o College Students' Identity Negotiation in Figured Worlds

ERIC Educational Resources Information Center

Pena-Talamantes, Abraham E.

2013-01-01

Drawing from Holland, Lachicotte, Skinner, and Cain's (1998) identity theory, this study sought to understand how six self-identified lesbian and gay Latina/o college students negotiated their sexual and ethnic identities. Participants identified two equally flawed dimensions, the hometown and college figured worlds, from which they sought an…

Not All Emotions Are Created Equal: The Negativity Bias in Social-Emotional Development

ERIC Educational Resources Information Center

Vaish, Amrisha; Grossman, Tobias; Woodward, Amanda

2008-01-01

There is ample empirical evidence for an asymmetry in the way that adults use positive versus negative information to make sense of their world; specifically, across an array of psychological situations and tasks, adults display a negativity bias, or the propensity to attend to, learn from, and use negative information far more than positive…

The Role of Boards in College Access Programs: Creating and Maintaining Quality

ERIC Educational Resources Information Center

Center for Higher Education Policy Analysis, University of Southern California, 2006

2006-01-01

Access programs are facing increased scrutiny. Not all programs are equally effective. In an environment in which resources are short, funders increasingly require criteria that enable them to make informed decisions about program quality. As elaborated in this report , one role of a high performance board is to help develop benchmarks of…

Non-Performativity of University and Subjectification of Students: The Question of Equality and Diversity in UK Universities

ERIC Educational Resources Information Center

Kimura, Maki

2014-01-01

Universities in the United Kingdom have experienced a transformation in the context of the government's initiatives to widen participation and rapid socio-economic changes locally and globally. With more diverse students entering higher education, universities need to consider how they can create an inclusive environment. Indeed, in order to…

An Overview of Peace Education in Turkey: Definitions, Difficulties, and Suggestions--A Qualitative Analysis

ERIC Educational Resources Information Center

Demir, Semra

2011-01-01

In modern world, advances and changes experienced in social, political, and economic domains cannot be effective in diminishing the unwanted behaviors displayed by individuals in a society. This underpins the need for creating a peace culture based on equality, justice, democracy, human rights, tolerance, and solidarity in a society. The purpose…

Oasis of Dreams: Teaching and Learning Peace in a Jewish-Palestinian Village in Israel.

ERIC Educational Resources Information Center

Feuerverger, Grace

This book provides an interpretive/ethnographic inquiry into the relationship between Jews and Palestinians who live in a small cooperative community and into its two schools, which are devoted to peaceful coexistence. The village aims to create a social, cultural, and political framework of equality and mutual respect for the residents while…

Not All Analogies Are Created Equal: Associative and Categorical Analogy Processing following Brain Damage

ERIC Educational Resources Information Center

Schmidt, Gwenda L.; Cardillo, Eileen R.; Kranjec, Alexander; Lehet, Matthew; Widick, Page; Chatterjee, Anjan

2012-01-01

Current research on analogy processing assumes that different conceptual relations are treated similarly. However, just as words and concepts are related in distinct ways, different kinds of analogies may employ distinct types of relationships. An important distinction in how words are related is the difference between associative (dog-bone) and…

Material and Optical Densities

ERIC Educational Resources Information Center

Gluck, Paul

2007-01-01

The bending of a laser beam in a medium with a density and refractive index gradient in the same direction has been described previously. When a transparent container is half filled with a salt or sugar solution and an equal amount of water is floated on top of it, then diffusion will create a concentration gradient from top to bottom. A laser…

2014 Wallace Foundation Distinguished Lecture--Rigor and Realism: Doing Educational Science in the Real World

ERIC Educational Resources Information Center

Snow, Catherine E.

2015-01-01

Transcending the low status of educational research will require demonstrating its relevance to improvements in practice. Educational progress is most likely to emerge from approaches to research that create an equal footing for practitioners and researchers, recognizing that though these groups accumulate and curate knowledge in different ways,…

Multiculturalism on Campus: Theory, Models, and Practices for Understanding Diversity and Creating Inclusion

ERIC Educational Resources Information Center

Cuyjet, Michael J., Ed.; Howard-Hamilton, Mary F., Ed.; Cooper, Diane L., Ed.

2011-01-01

As the diversity of the students on campus increases, the importance for everyone in authority to understand students' distinct cultures and how they perceive institutions, and equally, to understand their own privilege, and often unconscious cultural assumptions, has never been greater. This book presents a comprehensive set of resources to guide…

Semantic Interaction in Early and Late Bilinguals: All Words Are Not Created Equally

ERIC Educational Resources Information Center

Gathercole, Virginia C. Mueller; Moawad, Ruba Abdelmatloub

2010-01-01

This study examines L1-L2 interaction in semantic categorization in early and late L2 learners. Word categories that overlapped but were not identical in Arabic and English were tested. Words always showed a "wider" range of application in one language, "narrower" in the other. Three types of categories--"classical", "radial", and…

Reflections on the Invisible: The Missing Social Context in Therapy.

ERIC Educational Resources Information Center

Hare-Mustin, Rachel T.

Constructivist approaches to therapy that view the therapist and patient as equal participants in co-creating a new dialogue render aspects of experience invisible. What is missing is an awareness of the dominant structures in society and the dominant ways of thinking and speaking. Three key factors need to be understood: first, the way meanings…

An Agency with a Mind of Its Own: The EEOC's Guidelines on Employment Testing.

ERIC Educational Resources Information Center

Lyons, Phil

1985-01-01

Analyzes the legislative and judicial background of the Equal Employment Opportunities Commission (EEOC)'s 1978 Uniform Guidelines on Employment Selection Procedures. Argues that the guidelines' apparent objectives are at odds with those of the legislators who created the EEOC in the 1960s: the guidelines force employers to discriminate by race.…

Designing Creative Spaces for Idea Generation and Start-Up Experiments: The Role of University Ecosystems

ERIC Educational Resources Information Center

Curley, Martin; Formica, Piero

2013-01-01

The role of universities is changing. In the last century the primary focus of universities was on education and research, with the key goals of creating and diffusing information and knowledge. A third and equally important role is now emerging, with its accompanying expectations and responsibilities -- that of value creation. "Value"…

Anti-Bullying Procedures for Schools in Ireland: Principals' Responses and Perceptions

ERIC Educational Resources Information Center

Foody, Mairéad; Murphy, Helena; Downes, Paul; O'Higgins Norman, James

2018-01-01

The role of the principal is imperative in creating a school climate that nurtures differences and equality at the same time. Policy and legislation in Ireland dictates the responsibility of school principals in preventing and intervening in issues relating to bullying. The current research investigates the extent to which principals consider the…

Changing against the Grain: Academy for Peace in a Reality of Conflict

ERIC Educational Resources Information Center

Hager, Tamar; Saba, Tuffaha

2009-01-01

This article recounts an attempt by administration and faculty to create a multinational and multicultural vision for Tel Hai Academic College in the Galilee in Israel. This uncommon initiative in the Israeli academia intends to transform the campus into a unique academic institution allowing equality and visibility for all cultural and national…

The Future of Education: Innovations Needed to Meet the Sustainable Development Goals

ERIC Educational Resources Information Center

Pota, Vikas

2017-01-01

In autumn 2015, the world's governments came together to agree to 17 ambitious Sustainable Development Goals (SDGs), which promised to overcome a vast array of problems--from poverty and hunger to health and gender equality--by 2030. The UNESCO report "Education for People and Planet: Creating Sustainable Futures for All" charted the…

Particle size distribution characteristics of cotton gin battery condenser system total particulate emissions

USDA-ARS?s Scientific Manuscript database

This report is part of a project to characterize cotton gin emissions from the standpoint of total particulate stack sampling and particle size analyses. In 2013, EPA published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created a...

Not All Lexical Access Tasks Are Created Equal: Lexical Development between Three and Five

ERIC Educational Resources Information Center

Isacoff, Nora M.; Stromswold, Karin

2014-01-01

Lexical access tasks are designed to measure efficiency of lexical access, but task demands and methods vary greatly. Many lexical access tasks do not account for confounding factors including competence in other linguistic abilities. In this study, preschoolers were given two lexical access tasks. In the single-category naming (SCN) task,…

School Location and Teacher Supply: Understanding the Distribution of Teacher Effects

ERIC Educational Resources Information Center

Gagnon, Douglas

2015-01-01

The U.S. Department of Education has recently called on all states to create plans to ensure equal access to excellent teachers. Although there are numerous limitations in using VAM [value-added modeling] in high-stakes contexts such as teacher evaluation, such techniques offer promise in helping states grapple with issues in equitable access.…

Race-Conscious Educational Policies versus a "Color-Blind Constitution": A Historical Perspective

ERIC Educational Resources Information Center

Anderson, James D.

2007-01-01

This article examines the origins and development of citizenship and equal rights by the Reconstruction Congress (1865-1875) to determine if it created a new constitutional order that is color blind and thus prohibits the use of racial classifications by government to achieve school desegregation and affirmative action programs. The theory of…

The Social Network: Keeping in Touch with Alumni through Online Media

ERIC Educational Resources Information Center

Bunker, Matt

2011-01-01

Not all social-networking tools are created equal. Knowing where alumni are and what they're doing online is key when deciding what social networks to use. Knowing how to address and employ social networking can change the way institutions engage alumni. Social media help institutions connect with alumni; these tools help build, sustain, and even…

MOAB: a spatially explicit, individual-based expert system for creating animal foraging models

USGS Publications Warehouse

Carter, J.; Finn, John T.

1999-01-01

We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a goven species on that landscape to simultaneously simulate the foraging behavior of multiple species. The heuristic rules for animal behavior are maintained in a user-modifiable expert system. MOAB can be used to explore hypotheses concerning the influence of landscape patttern on animal movement and foraging behavior. A red fox (Vulpes vulpes L.) foraging and nest predation model was created to test MOAB's capabilities. Foxes were simulated for 30-day periods using both expert system and random movement rules. Home range size, territory formation and other available simulation studies. A striped skunk (Mephitis mephitis L.) model also was developed. The expert system model proved superior to stochastic in respect to territory formation, general movement patterns and home range size.

Computed tomography and (18)F-fluorodeoxyglucose positron emission tomography/computed tomography findings in adrenal candidiasis and histoplasmosis: two cases.

PubMed

Altinmakas, Emre; Guo, Ming; Kundu, Uma R; Habra, Mouhammed Amir; Ng, Chaan

2015-01-01

We report the contrast-enhanced computed tomography (CT) and (18)F-fluorodeoxyglucose positron emission tomography findings in adrenal histoplasmosis and candidiasis. Both demonstrated bilateral hypermetabolic heterogeneous adrenal masses with limited wash-out on delayed CT. Adrenal candidiasis has not been previously reported, nor have the CT wash-out findings in either infection. The adrenal imaging findings are indistinguishable from malignancy, which is more common; but in this setting, physicians should be alert to the differential diagnosis of fungal infections, since it can be equally deadly. Published by Elsevier Inc.

Madelung’s Disease – Case Series and Treatment by Tumescent Liposuction or Lipectomy

PubMed Central

Wollina, Uwe; Heinig, Birgit

2017-01-01

Madelung disease is a disfiguring disorder belonging to the heterogeneous group of lipomatosis. The aetiology is not well understood, but alcohol consumption has been regarded as of importance. The reported incidence is about 1 in 25,000 inhabitants. We reviewed our files of the last ten years and identified eight adult patients with an equal gender distribution. Their age was between 60 and 85 years of life. Comorbidities are frequent. Clinical presentation may vary. Surgical treatment is reported and discussed. Both cold steel surgery and tumescent liposuction have their place in treatment. PMID:28785324

Functional correlation approach to operational risk in banking organizations

NASA Astrophysics Data System (ADS)

Kühn, Reimer; Neu, Peter

2003-05-01

A Value-at-Risk-based model is proposed to compute the adequate equity capital necessary to cover potential losses due to operational risks, such as human and system process failures, in banking organizations. Exploring the analogy to a lattice gas model from physics, correlations between sequential failures are modeled by as functionally defined, heterogeneous couplings between mutually supportive processes. In contrast to traditional risk models for market and credit risk, where correlations are described as equal-time-correlations by a covariance matrix, the dynamics of the model shows collective phenomena such as bursts and avalanches of process failures.

Different osteochondral potential of clonal cell lines derived from adult human trabecular bone.

PubMed

Osyczka, Anna M; Nöth, Ulrich; Danielson, Keith G; Tuan, Rocky S

2002-06-01

Cells derived from human trabecular bones have been shown to have multipotential differentiation ability along osteogenic, chondrogenic, and adipogenic lineages. In this study, we have derived two clonal sublines of human trabecular bone cells by means of stable transduction with human papilloma virus E6/E7 genes. Our results showed that these clonal sublines differ in their osteochondral potential, but are equally adipogenic, indicative of the heterogeneous nature of the parental cell population. The availability of these cell lines should be useful for the analysis of the mechanisms regulating the differentiation of adult mesenchymal progenitor cells.

Nosology, ontology and promiscuous realism.

PubMed

Binney, Nicholas

2015-06-01

Medics may consider worrying about their metaphysics and ontology to be a waste of time. I will argue here that this is not the case. Promiscuous realism is a metaphysical position which holds that multiple, equally valid, classification schemes should be applied to objects (such as patients) to capture different aspects of their complex and heterogeneous nature. As medics at the bedside may need to capture different aspects of their patients' problems, they may need to use multiple classification schemes (multiple nosologies), and thus consider adopting a different metaphysics to the one commonly in use. © 2014 John Wiley & Sons, Ltd.

Modeling the effect of soil structure on water flow and isoproturon dynamics in an agricultural field receiving repeated urban waste compost application.

PubMed

Filipović, Vilim; Coquet, Yves; Pot, Valérie; Houot, Sabine; Benoit, Pierre

2014-11-15

Transport processes in soils are strongly affected by heterogeneity of soil hydraulic properties. Tillage practices and compost amendments can modify soil structure and create heterogeneity at the local scale within agricultural fields. The long-term field experiment QualiAgro (INRA-Veolia partnership 1998-2013) explores the impact of heterogeneity in soil structure created by tillage practices and compost application on transport processes. A modeling study was performed to evaluate how the presence of heterogeneity due to soil tillage and compost application affects water flow and pesticide dynamics in soil during a long-term period. The study was done on a plot receiving a co-compost of green wastes and sewage sludge (SGW) applied once every 2 years since 1998. The plot was cultivated with a biannual rotation of winter wheat-maize (except 1 year of barley) and a four-furrow moldboard plow was used for tillage. In each plot, wick lysimeter outflow and TDR probe data were collected at different depths from 2004, while tensiometer measurements were also conducted during 2007/2008. Isoproturon concentration was measured in lysimeter outflow since 2004. Detailed profile description was used to locate different soil structures in the profile, which was then implemented in the HYDRUS-2D model. Four zones were identified in the plowed layer: compacted clods with no visible macropores (Δ), non-compacted soil with visible macroporosity (Γ), interfurrows created by moldboard plowing containing crop residues and applied compost (IF), and the plow pan (PP) created by plowing repeatedly to the same depth. Isoproturon retention and degradation parameters were estimated from laboratory batch sorption and incubation experiments, respectively, for each structure independently. Water retention parameters were estimated from pressure plate laboratory measurements and hydraulic conductivity parameters were obtained from field tension infiltrometer experiments. Soil hydraulic properties were optimized on one calibration year (2007/08) using pressure head, water content and lysimeter outflow data, and then tested on the whole 2004/2010 period. Lysimeter outflow and water content dynamics in the soil profile were correctly described for the whole period (model efficiency coefficient: 0.99) after some correction of LAI estimates for wheat (2005/06) and barley (2006/07). Using laboratory-measured degradation rates and assuming degradation only in the liquid phase caused large overestimation of simulated isoproturon losses in lysimeter outflow. A proper order of magnitude of isoproturon losses was obtained after considering that degradation occurred in solid (sorbed) phase at a rate 75% of that in liquid phase. Isoproturon concentrations were found to be highly sensitive to degradation rates. Neither the laboratory-measured isoproturon fate parameters nor the independently-derived soil hydraulic parameters could describe the actual multiannual field dynamics of water and isoproturon without calibration. However, once calibrated on a limited period of time (9 months), HYDRUS-2D was able to simulate the whole 6-year time series with good accuracy. Copyright © 2014 Elsevier B.V. All rights reserved.

Patterns of Gender Equality at Workplaces and Psychological Distress

PubMed Central

Bolin, Malin; Hammarström, Anne

2013-01-01

Research in the field of occupational health often uses a risk factor approach which has been criticized by feminist researchers for not considering the combination of many different variables that are at play simultaneously. To overcome this shortcoming this study aims to identify patterns of gender equality at workplaces and to investigate how these patterns are associated with psychological distress. Questionnaire data from the Northern Swedish Cohort (n = 715) have been analysed and supplemented with register data about the participants' workplaces. The register data were used to create gender equality indicators of women/men ratios of number of employees, educational level, salary and parental leave. Cluster analysis was used to identify patterns of gender equality at the workplaces. Differences in psychological distress between the clusters were analysed by chi-square test and logistic regression analyses, adjusting for individual socio-demographics and previous psychological distress. The cluster analysis resulted in six distinctive clusters with different patterns of gender equality at the workplaces that were associated to psychological distress for women but not for men. For women the highest odds of psychological distress was found on traditionally gender unequal workplaces. The lowest overall occurrence of psychological distress as well as same occurrence for women and men was found on the most gender equal workplaces. The results from this study support the convergence hypothesis as gender equality at the workplace does not only relate to better mental health for women, but also more similar occurrence of mental ill-health between women and men. This study highlights the importance of utilizing a multidimensional view of gender equality to understand its association to health outcomes. Health policies need to consider gender equality at the workplace level as a social determinant of health that is of importance for reducing differences in health outcomes for women and men. PMID:23326404

Changing masculinities: land-use, family communication and prospects for working with older men towards gender equality in a livelihoods intervention.

PubMed

Jobson, Geoffrey

2010-04-01

Engaging men in work towards gender equality is a critical aspect of gender and development. However, there are few documented grassroots-level approaches to undertaking such work. This paper argues that context specific stresses on local constructions of masculinity, such as unemployment, poverty and high HIV prevalence, may provide useful entry points for work with men towards gender equality. While these stresses may act to undermine men's ability to 'achieve' the requirements of traditional constructions of masculinity, particularly the role of men as providers, they simultaneously create spaces for change. In this research, land-use provided a basis from which to engage with a group of older men (45-75 years) around a range of issues, including HIV and AIDS and health. Increases in levels of communication around HIV, household resources and health are used as indicative of the men's moves towards gender-equal behaviour. The paper argues that this was achieved by supporting positive aspects of traditional masculine identities, particularly the role of men as breadwinners, in a social and economic context where these roles are threatened or placed under pressure, while simultaneously working around 'sensitive' issues.

Heterogeneous WS x/WO 3 thorn-bush nanofiber electrodes for sodium-ion batteries

DOE PAGES

Ryu, Won -Hee; Wilson, Hope; Sohn, Sungwoo; ...

2016-01-25

Heterogeneous electrode materials with hierarchical architectures promise to enable considerable improvement in future energy storage devices. In this study, we report on a tailored synthetic strategy used to create heterogeneous tungsten sulfide/oxide core–shell nanofiber materials with vertically and randomly aligned thorn-bush features, and we evaluate them as potential anode materials for high-performance Na-ion batteries. The WS x (2 ≤ x ≤ 3, amorphous WS 3 and crystalline WS 2) nanofiber is successfully prepared by electrospinning and subsequent calcination in a reducing atmosphere. To prevent capacity degradation of the WS x anodes originating from sulfur dissolution, a facile post-thermal treatment inmore » air is applied to form an oxide passivation surface. Interestingly, WO 3 thorn bundles are randomly grown on the nanofiber stem, resulting from the surface conversion. We elucidate the evolving morphological and structural features of the nanofibers during post-thermal treatment. The heterogeneous thorn-bush nanofiber electrodes deliver a high second discharge capacity of 791 mAh g –1 and improved cycle performance for 100 cycles compared to the pristine WS x nanofiber. Lastly, we show that this hierarchical design is effective in reducing sulfur dissolution, as shown by cycling analysis with counter Na electrodes.« less

Influences of granular constraints and surface effects on the heterogeneity of elastic, superelastic, and plastic responses of polycrystalline shape memory alloys

DOE PAGES

Paranjape, Harshad M.; Paul, Partha P.; Sharma, Hemant; ...

2017-02-16

Deformation heterogeneities at the microstructural length-scale developed in polycrystalline shape memory alloys (SMAs) during superelastic loading are studied using both experiments and simulations. In situ X-ray diffraction, specifically the far-field high energy diffraction microscopy (ff-HEDM) technique, was used to non-destructively measure the grain-averaged statistics of position, crystal orientation, elastic strain tensor, and volume for hundreds of austenite grains in a superelastically loaded nickel-titanium (NiTi) SMA. These experimental data were also used to create a synthetic microstructure within a finite element model. The development of intragranular stresses were then simulated during tensile loading of the model using anisotropic elasticity. Driving forcesmore » for phase transformation and slip were calculated from these stresses. The grain-average responses of individual austenite crystals examined before and after multiple stress-induced transformation events showed that grains in the specimen interior carry more axial stress than the surface grains as the superelastic response "shakes down". Examination of the heterogeneity within individual grains showed that regions near grain boundaries exhibit larger stress variation compared to the grain interiors. As a result, this intragranular heterogeneity is more strongly driven by the constraints of neighboring grains than the initial stress state and orientation of the individual grains.« less

Influences of granular constraints and surface effects on the heterogeneity of elastic, superelastic, and plastic responses of polycrystalline shape memory alloys

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

Paranjape, Harshad M.; Paul, Partha P.; Sharma, Hemant

Deformation heterogeneities at the microstructural length-scale developed in polycrystalline shape memory alloys (SMAs) during superelastic loading are studied using both experiments and simulations. In situ X-ray diffraction, specifically the far-field high energy diffraction microscopy (ff-HEDM) technique, was used to non-destructively measure the grain-averaged statistics of position, crystal orientation, elastic strain tensor, and volume for hundreds of austenite grains in a superelastically loaded nickel-titanium (NiTi) SMA. These experimental data were also used to create a synthetic microstructure within a finite element model. The development of intragranular stresses were then simulated during tensile loading of the model using anisotropic elasticity. Driving forcesmore » for phase transformation and slip were calculated from these stresses. The grain-average responses of individual austenite crystals examined before and after multiple stress-induced transformation events showed that grains in the specimen interior carry more axial stress than the surface grains as the superelastic response "shakes down". Examination of the heterogeneity within individual grains showed that regions near grain boundaries exhibit larger stress variation compared to the grain interiors. As a result, this intragranular heterogeneity is more strongly driven by the constraints of neighboring grains than the initial stress state and orientation of the individual grains.« less

Kleptothermy: an additional category of thermoregulation, and a possible example in sea kraits (Laticauda laticaudata, Serpentes)

PubMed Central

Brischoux, François; Bonnet, Xavier; Shine, Richard

2009-01-01

Lacking the capacity for thermogenesis, most ectotherms inhabiting thermally heterogeneous environments rely instead upon exploiting that ambient heterogeneity. In many cases they maintain body temperatures within a narrow range despite massive spatial and temporal variation in ambient conditions. Reliance on diverse thermal opportunities is reflected in specific terms for organisms that bask in sunlight to regulate their temperature (heliotherms), or that press their bodies against warm substrates to facilitate heat flow (thigmotherms), or that rely on large body mass to maintain thermal constancy (gigantothermy). We propose an additional category of thermoregulators: kleptotherms, which regulate their own temperature by ‘stealing’ heat from other organisms. This concept involves two major conditions: the thermal heterogeneity created by the presence of a warm organism in a cool environment and the selective use of that heterogeneity by another animal to maintain body temperatures at higher (and more stable) levels than would be possible elsewhere in the local area. Kleptothermy occurs in endotherms also, but is usually reciprocal (rather than unilateral as in ectotherms). Thermal monitoring on a small tropical island documents a possible example of kleptothermy, based on high stable temperatures of a sea snake (Laticauda laticaudata) inside a burrow occupied by seabirds. PMID:19656862

Visualizing Intrapopulation Hematopoietic Cell Heterogeneity with Self-Organizing Maps of SIMS Data.

PubMed

Mirshafiee, Vahid; Harley, Brendan A C; Kraft, Mary L

2018-05-07

Characterization of the heterogeneity within stem cell populations, which affects their differentiation potential, is necessary for the design of artificial cultures for stem cell expansion. In this study, we assessed whether self-organizing maps (SOMs) of single-cell time-of-flight secondary ion mass spectrometry (TOF-SIMS) data provide insight into the spectral, and thus the related functional heterogeneity between and within three hematopoietic cell populations. SOMs were created of TOF-SIMS data from individual hematopoietic stem and progenitor cells (HSPCs), lineage-committed common lymphoid progenitors (CLPs), and fully differentiated B cells that had been isolated from murine bone marrow via conventional flow cytometry. The positions of these cells on the SOMs and the spectral variation between adjacent map units, shown on the corresponding unified distance matrix (U-matrix), indicated the CLPs exhibited the highest intrapopulation spectral variation, regardless of the age of the donor mice. SOMs of HSPCs, CLPs, and B cells isolated from young and old mice using the same surface antigen profiles revealed the HSPCs exhibited the most age-related spectral variation, whereas B cells exhibited the least. These results demonstrate that SOMs of single-cell spectra enable characterizing the heterogeneity between and within cell populations that lie along distinct differentiation pathways.

Microbial micropatches within microbial hotspots.

PubMed

Dann, Lisa M; McKerral, Jody C; Smith, Renee J; Tobe, Shanan S; Paterson, James S; Seymour, Justin R; Oliver, Rod L; Mitchell, James G

2018-01-01

The spatial distributions of organism abundance and diversity are often heterogeneous. This includes the sub-centimetre distributions of microbes, which have 'hotspots' of high abundance, and 'coldspots' of low abundance. Previously we showed that 300 μl abundance hotspots, coldspots and background regions were distinct at all taxonomic levels. Here we build on these results by showing taxonomic micropatches within these 300 μl microscale hotspots, coldspots and background regions at the 1 μl scale. This heterogeneity among 1 μl subsamples was driven by heightened abundance of specific genera. The micropatches were most pronounced within hotspots. Micropatches were dominated by Pseudomonas, Bacteroides, Parasporobacterium and Lachnospiraceae incertae sedis, with Pseudomonas and Bacteroides being responsible for a shift in the most dominant genera in individual hotspot subsamples, representing up to 80.6% and 47.3% average abundance, respectively. The presence of these micropatches implies the ability these groups have to create, establish themselves in, or exploit heterogeneous microenvironments. These genera are often particle-associated, from which we infer that these micropatches are evidence for sub-millimetre aggregates and the aquatic polymer matrix. These findings support the emerging paradigm that the microscale distributions of planktonic microbes are numerically and taxonomically heterogeneous at scales of millimetres and less. We show that microscale microbial hotspots have internal structure within which specific local nutrient exchanges and cellular interactions might occur.