WorldWideScience

Sample records for surrogate species concept

  1. Environmental diversity as a surrogate for species representation.

    Science.gov (United States)

    Beier, Paul; de Albuquerque, Fábio Suzart

    2015-10-01

    Because many species have not been described and most species ranges have not been mapped, conservation planners often use surrogates for conservation planning, but evidence for surrogate effectiveness is weak. Surrogates are well-mapped features such as soil types, landforms, occurrences of an easily observed taxon (discrete surrogates), and well-mapped environmental conditions (continuous surrogate). In the context of reserve selection, the idea is that a set of sites selected to span diversity in the surrogate will efficiently represent most species. Environmental diversity (ED) is a rarely used surrogate that selects sites to efficiently span multivariate ordination space. Because it selects across continuous environmental space, ED should perform better than discrete surrogates (which necessarily ignore within-bin and between-bin heterogeneity). Despite this theoretical advantage, ED appears to have performed poorly in previous tests of its ability to identify 50 × 50 km cells that represented vertebrates in Western Europe. Using an improved implementation of ED, we retested ED on Western European birds, mammals, reptiles, amphibians, and combined terrestrial vertebrates. We also tested ED on data sets for plants of Zimbabwe, birds of Spain, and birds of Arizona (United States). Sites selected using ED represented European mammals no better than randomly selected cells, but they represented species in the other 7 data sets with 20% to 84% effectiveness. This far exceeds the performance in previous tests of ED, and exceeds the performance of most discrete surrogates. We believe ED performed poorly in previous tests because those tests considered only a few candidate explanatory variables and used suboptimal forms of ED's selection algorithm. We suggest future work on ED focus on analyses at finer grain sizes more relevant to conservation decisions, explore the effect of selecting the explanatory variables most associated with species turnover, and investigate

  2. Species concepts and species delimitation.

    Science.gov (United States)

    De Queiroz, Kevin

    2007-12-01

    The issue of species delimitation has long been confused with that of species conceptualization, leading to a half century of controversy concerning both the definition of the species category and methods for inferring the boundaries and numbers of species. Alternative species concepts agree in treating existence as a separately evolving metapopulation lineage as the primary defining property of the species category, but they disagree in adopting different properties acquired by lineages during the course of divergence (e.g., intrinsic reproductive isolation, diagnosability, monophyly) as secondary defining properties (secondary species criteria). A unified species concept can be achieved by treating existence as a separately evolving metapopulation lineage as the only necessary property of species and the former secondary species criteria as different lines of evidence (operational criteria) relevant to assessing lineage separation. This unified concept of species has several consequences for species delimitation, including the following: First, the issues of species conceptualization and species delimitation are clearly separated; the former secondary species criteria are no longer considered relevant to species conceptualization but only to species delimitation. Second, all of the properties formerly treated as secondary species criteria are relevant to species delimitation to the extent that they provide evidence of lineage separation. Third, the presence of any one of the properties (if appropriately interpreted) is evidence for the existence of a species, though more properties and thus more lines of evidence are associated with a higher degree of corroboration. Fourth, and perhaps most significantly, a unified species concept shifts emphasis away from the traditional species criteria, encouraging biologists to develop new methods of species delimitation that are not tied to those properties.

  3. A review of selection-based tests of abiotic surrogates for species representation.

    Science.gov (United States)

    Beier, Paul; Sutcliffe, Patricia; Hjort, Jan; Faith, Daniel P; Pressey, Robert L; Albuquerque, Fabio

    2015-06-01

    Because conservation planners typically lack data on where species occur, environmental surrogates--including geophysical settings and climate types--have been used to prioritize sites within a planning area. We reviewed 622 evaluations of the effectiveness of abiotic surrogates in representing species in 19 study areas. Sites selected using abiotic surrogates represented more species than an equal number of randomly selected sites in 43% of tests (55% for plants) and on average improved on random selection of sites by about 8% (21% for plants). Environmental diversity (ED) (42% median improvement on random selection) and biotically informed clusters showed promising results and merit additional testing. We suggest 4 ways to improve performance of abiotic surrogates. First, analysts should consider a broad spectrum of candidate variables to define surrogates, including rarely used variables related to geographic separation, distance from coast, hydrology, and within-site abiotic diversity. Second, abiotic surrogates should be defined at fine thematic resolution. Third, sites (the landscape units prioritized within a planning area) should be small enough to ensure that surrogates reflect species' environments and to produce prioritizations that match the spatial resolution of conservation decisions. Fourth, if species inventories are available for some planning units, planners should define surrogates based on the abiotic variables that most influence species turnover in the planning area. Although species inventories increase the cost of using abiotic surrogates, a modest number of inventories could provide the data needed to select variables and evaluate surrogates. Additional tests of nonclimate abiotic surrogates are needed to evaluate the utility of conserving nature's stage as a strategy for conservation planning in the face of climate change. © 2015 Society for Conservation Biology.

  4. Selecting a Conservation Surrogate Species for Small Fragmented Habitats Using Ecological Niche Modelling

    Directory of Open Access Journals (Sweden)

    K. Anne-Isola Nekaris

    2015-01-01

    Full Text Available Flagship species are traditionally large, charismatic animals used to rally conservation efforts. Accepted flagship definitions suggest they need only fulfil a strategic role, unlike umbrella species that are used to shelter cohabitant taxa. The criteria used to select both flagship and umbrella species may not stand up in the face of dramatic forest loss, where remaining fragments may only contain species that do not suit either set of criteria. The Cinderella species concept covers aesthetically pleasing and overlooked species that fulfil the criteria of flagships or umbrellas. Such species are also more likely to occur in fragmented habitats. We tested Cinderella criteria on mammals in the fragmented forests of the Sri Lankan Wet Zone. We selected taxa that fulfilled both strategic and ecological roles. We created a shortlist of ten species, and from a survey of local perceptions highlighted two finalists. We tested these for umbrella characteristics against the original shortlist, utilizing Maximum Entropy (MaxEnt modelling, and analysed distribution overlap using ArcGIS. The criteria highlighted Loris tardigradus tardigradus and Prionailurus viverrinus as finalists, with the former having highest flagship potential. We suggest Cinderella species can be effective conservation surrogates especially in habitats where traditional flagship species have been extirpated.

  5. Midwest Surrogate Species and Prairie Reconstruction Funding Final Report, FY 2016

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Final report on funding received from the Natural Resources Program Center to support surrogate species planning and implementation and the Prairie Reconstruction...

  6. Selecting focal species as surrogates for imperiled species using relative sensitivities derived from occupancy analysis

    Science.gov (United States)

    Silvano, Amy; Guyer, Craig; Steury, Todd; Grand, James B.

    2017-01-01

    Most imperiled species are rare or elusive and difficult to detect, which makes gathering data to estimate their response to habitat restoration a challenge. We used a repeatable, systematic method for selecting focal species using relative sensitivities derived from occupancy analysis. Our objective was to select suites of focal species that would be useful as surrogates when predicting effects of restoration of habitat characteristics preferred by imperiled species. We developed 27 habitat profiles that represent general habitat relationships for 118 imperiled species. We identified 23 regularly encountered species that were sensitive to important aspects of those profiles. We validated our approach by examining the correlation between estimated probabilities of occupancy for species of concern and focal species selected using our method. Occupancy rates of focal species were more related to occupancy rates of imperiled species when they were sensitive to more of the parameters appearing in profiles of imperiled species. We suggest that this approach can be an effective means of predicting responses by imperiled species to proposed management actions. However, adequate monitoring will be required to determine the effectiveness of using focal species to guide management actions.

  7. Incorporating surrogate species and seascape connectivity to improve marine conservation outcomes.

    Science.gov (United States)

    Olds, Andrew D; Connolly, Rod M; Pitt, Kylie A; Maxwell, Paul S; Aswani, Shankar; Albert, Simon

    2014-08-01

    Conservation focuses on maintaining biodiversity and ecosystem functioning, but gaps in our knowledge of species biology and ecological processes often impede progress. For this reason, focal species and habitats are used as surrogates for multispecies conservation, but species-based approaches are not widely adopted in marine ecosystems. Reserves in the Solomon Islands were designed on the basis of local ecological knowledge to conserve bumphead parrotfish (Bolbometopon muricatum) and to protect food security and ecosystem functioning. Bumphead parrotfish are an iconic threatened species and may be a useful surrogate for multispecies conservation. They move across tropical seascapes throughout their life history, in a pattern of habitat use that is shared with many other species. We examined their value as a conservation surrogate and assessed the importance of seascape connectivity (i.e., the physical connectedness of patches in the seascape) among reefs, mangroves, and seagrass to marine reserve performance. Reserves were designed for bumphead parrotfish, but also enhanced the abundance of other species. Integration of local ecological knowledge and seascape connectivity enhanced the abundance of 17 other harvested fish species in local reserves. This result has important implications for ecosystem functioning and local villagers because many of these species perform important ecological processes and provide the foundation for extensive subsistence fisheries. Our findings suggest greater success in maintaining and restoring marine ecosystems may be achieved when they are managed to conserve surrogate species and preserve functional seascape connections. © 2014 Society for Conservation Biology.

  8. Evaluating β Diversity as a Surrogate for Species Representation at Fine Scale.

    Directory of Open Access Journals (Sweden)

    Paul Beier

    Full Text Available Species turnover or β diversity is a conceptually attractive surrogate for conservation planning. However, there has been only 1 attempt to determine how well sites selected to maximize β diversity represent species, and that test was done at a scale too coarse (2,500 km2 sites to inform most conservation decisions. We used 8 plant datasets, 3 bird datasets, and 1 mammal dataset to evaluate whether sites selected to span β diversity will efficiently represent species at finer scale (sites sizes < 1 ha to 625 km2. We used ordinations to characterize dissimilarity in species assemblages (β diversity among plots (inventory data or among grid cells (atlas data. We then selected sites to maximize β diversity and used the Species Accumulation Index, SAI, to evaluate how efficiently the surrogate (selecting sites for maximum β diversity represented species in the same taxon. Across all 12 datasets, sites selected for maximum β diversity represented species with a median efficiency of 24% (i.e., the surrogate was 24% more effective than random selection of sites, and an interquartile range of 4% to 41% efficiency. β diversity was a better surrogate for bird datasets than for plant datasets, and for atlas datasets with 10-km to 14-km grid cells than for atlas datasets with 25-km grid cells. We conclude that β diversity is more than a mere descriptor of how species are distributed on the landscape; in particular β diversity might be useful to maximize the complementarity of a set of sites. Because we tested only within-taxon surrogacy, our results do not prove that β diversity is useful for conservation planning. But our results do justify further investigation to identify the circumstances in which β diversity performs well, and to evaluate it as a cross-taxon surrogate.

  9. Syrphid community in organic olive groves: can morphospecies be used as surrogates for species?

    OpenAIRE

    2012-01-01

    Syrphids are known as biological control agents of hemipteran pests and, in the olive grove, several species have been identified as predators of Euphyllura olivina (Costa). The objectives of this work were: (1) to study the syrphid community in organic olive groves and (2) to test the potential for the use of syrphid morphospecies as a surrogate for species. The field work was conducted in two organic olive groves located near Mirandela (Northeast of Portugal). The sampling perio...

  10. Sheepshead minnows (Cyprinodon variegatus) as a surrogate species in assessing contaminant risk to two endangered cyprinodontids

    Energy Technology Data Exchange (ETDEWEB)

    Brecken-Folse, J.; Albrecht, B. [TRAC Labs., Gulf Breeze, FL (United States); Mayer, F. [Environmental Protection Agency, Gulf Breeze, FL (United States); Ellersieck, M. [Univ. of Missouri, Columbia, MO (United States); Sappington, L. [National Biological Service, Columbia, MO (United States)

    1995-12-31

    Sheepshead minnows (Cyprinodon variegatus) were tested as a surrogate species to assess contaminant risk for the endangered Leon Springs pupfish (C. bovinus) and desert pupfish (C. macularius). Acute toxicity tests were conducted with carbaryl, copper sulfate, 4-nonylphenol, pentachlorophenol, and permethrin in accordance with ASTM guidelines. Sheepshead minnows were always more sensitive than pupfish, but the differences were small. 96-h LC50s for sheepshead minnows and Leon Springs pupfish were, respectively: carbaryl (4.2 and 4.6 mg/L), copper sulfate (2.5 and 4.6 mg/L), 4-nonylphenol (0.46 and 0.48 mg/L), pentachlorophenol (0.05 and 0.08 mg/L), permethrin (1 7 and 21 ug/L). Only one test could be conducted with desert pupfish and carbaryl, with the sheepshead minnow being more sensitive (7.3 vs 4.2 mg/L). These data, along with other data from the US NBS, Columbia, MO (two surrogate and six endangered freshwater fishes), indicate that toxicity test data for surrogate fishes can be used reliably to predict chemical toxicity to endangered fishes by interspecies correlations. However, the correlations were generally best within a family, particularly with the Cyprinodontids.

  11. Concepts of keystone species and species importance in ecology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper discussed the keystone species concept and introduced the typical characteristics of keystone species and their identification in communities or ecosystems. Based on the research of the keystone species, the concept of species importance (SI) was first advanced in this paper. The species importance can be simply understood as the important value of species in the ecosystem, which consists of three indexes: species structural important value (SIV), functional important value (FIV) and dynamical important value (DIV). With the indexes, the evaluation was also made on species importance of arbor trees in the Three-Hardwood forests (Fraxinus mandshurica, Juglans mandshurica, and Phellodendron amurense) ecosystem.

  12. Species concepts in Calonectria (Cylindrocladium)

    NARCIS (Netherlands)

    Lombard, L.; Crous, P.W.; Wingfield, B.D.; Wingfield, M.J.

    2010-01-01

    Species of Calonectria and their Cylindrocladium anamorphs are important plant pathogens worldwide. At present 52 Cylindrocladium spp. and 37 Calonectria spp. are recognised based on sexual compatibility, morphology and phylogenetic inference. The polyphasic approach of integrating Biological, Morph

  13. Limitations in dose-response and surrogate species methodologies for risk assessment of Cry toxins on arthropod natural enemies.

    Science.gov (United States)

    Paula, Débora P; Andow, David A; Bellinati, André; Timbó, Renata Velozo; Souza, Lucas M; Pires, Carmen S S; Sujii, Edison R

    2016-04-01

    Dose-response assays and surrogate species are standard methods for risk analysis for environmental chemicals. These assume that individuals within a species have unimodal responses and that a surrogate species can predict responses of other related taxa. We exposed immature individuals of closely related aphidophagous coccinellid predators, Cycloneda sanguinea and Harmonia axyridis, to Cry1Ac and Cry1F toxins through uniform and constant artificial tritrophic exposure through Myzus persicae aphids. Both toxins were detected in coccinellid pupae, with individual and interspecific variation. Uptake was significantly higher in H. axyridis than in C. sanguinea, both in the proportion of individuals and the concentrations per individual. We also observed bimodal uptake of the Cry toxins by H. axyridis, which indicated that some individuals had low bioaccumulation and some had high bioaccumulation. This suggests that standard dose-response assays need to be interpreted with caution and future assays should examine the modality of the responses. In addition, the similarity in the biological effects of the Cry toxins in the two predators was due to different biological exposure mechanisms. The majority of H. axyridis were exposed both internally and in the gut, while C. sanguinea was exposed primarily in the gut. Thus, despite their close phylogenetic relatedness, these species would not be good surrogates for each other and the surrogate species methodology should be tested more rigorously.

  14. Dynamic role and importance of surrogate species for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms

    Science.gov (United States)

    Surrogate species have a long history of use in research and regulatory settings to understand the potentially harmful effects of toxic substances including pesticides. More recently, surrogate species have been used to evaluate the potential effects of proteins contained in genetically engineered ...

  15. The keystone species concept: a critical appraisal

    Directory of Open Access Journals (Sweden)

    Robert J. Whittaker

    2012-09-01

    Full Text Available The keystone concept has been widely applied in the ecological literature since the idea was introduced in 1969. While it has been useful in framing biodiversity research and garnering support in conservation policy circles, the terminology surrounding the concept has been expanded to the extent that there is considerable confusion over what exactly a keystone species is. Several authors have argued that the term is too broadly applied, while others have pointed out the technical and theoretical limitations of the concept. Here, we chart the history of the keystone concept’s evolution and summarise the plethora of different terms and definitions currently in use. In reviewing these terms, we also analyse the value of the keystone concept and highlight some promising areas of recent work.

  16. Application of Design of Experiments and Surrogate Modeling within the NASA Advanced Concepts Office, Earth-to-Orbit Design Process

    Science.gov (United States)

    Zwack, Mathew R.; Dees, Patrick D.; Holt, James B.

    2016-01-01

    Decisions made during early conceptual design have a large impact upon the expected life-cycle cost (LCC) of a new program. It is widely accepted that up to 80% of such cost is committed during these early design phases. Therefore, to help minimize LCC, decisions made during conceptual design must be based upon as much information as possible. To aid in the decision making for new launch vehicle programs, the Advanced Concepts Office (ACO) at NASA Marshall Space Flight Center (MSFC) provides rapid turnaround pre-phase A and phase A concept definition studies. The ACO team utilizes a proven set of tools to provide customers with a full vehicle mass breakdown to tertiary subsystems, preliminary structural sizing based upon worst-case flight loads, and trajectory optimization to quantify integrated vehicle performance for a given mission. Although the team provides rapid turnaround for single vehicle concepts, the scope of the trade space can be limited due to analyst availability and the manpower requirements for manual execution of the analysis tools. In order to enable exploration of a broader design space, the ACO team has implemented an advanced design methods (ADM) based approach. This approach applies the concepts of design of experiments (DOE) and surrogate modeling to more exhaustively explore the trade space and provide the customer with additional design information to inform decision making. This paper will first discuss the automation of the ACO tool set, which represents a majority of the development effort. In order to fit a surrogate model within tolerable error bounds a number of DOE cases are needed. This number will scale with the number of variable parameters desired and the complexity of the system's response to those variables. For all but the smallest design spaces, the number of cases required cannot be produced within an acceptable timeframe using a manual process. Therefore, automation of the tools was a key enabler for the successful

  17. Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control

    Directory of Open Access Journals (Sweden)

    John E. Banks

    2017-07-01

    Full Text Available Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

  18. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals.

    Science.gov (United States)

    Ivey, Chris D; Besser, John M; Ingersoll, Chris G; Wang, Ning; Rogers, D Christopher; Raimondo, Sandy; Bauer, Candice R; Hammer, Edward J

    2017-03-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r(2 ) = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol

  19. Acute sensitivity of the vernal pool fairy shrimp, Branchinecta lynchi (Anostraca; Branchinectidae), and surrogate species to 10 chemicals

    Science.gov (United States)

    Ivey, Chris D.; Besser, John M.; Ingersoll, Christopher G.; Wang, Ning; Rogers, Christopher; Raimondo, Sandy; Bauer, Candice R.; Hammer, Edward J.

    2017-01-01

    Vernal pool fairy shrimp, Branchinecta lynchi, (Branchiopoda; Anostraca) and other fairy shrimp species have been listed as threatened or endangered under the US Endangered Species Act. Because few data exist about the sensitivity of Branchinecta spp. to toxic effects of contaminants, it is difficult to determine whether they are adequately protected by water quality criteria. A series of acute (24-h) lethality/immobilization tests was conducted with 3 species of fairy shrimp (B. lynchi, Branchinecta lindahli, and Thamnocephalus platyurus) and 10 chemicals with varying modes of toxic action: ammonia, potassium, chloride, sulfate, chromium(VI), copper, nickel, zinc, alachlor, and metolachlor. The same chemicals were tested in 48-h tests with other branchiopods (the cladocerans Daphnia magna and Ceriodaphnia dubia) and an amphipod (Hyalella azteca), and in 96-h tests with snails (Physa gyrina and Lymnaea stagnalis). Median effect concentrations (EC50s) for B. lynchi were strongly correlated (r2 = 0.975) with EC50s for the commercially available fairy shrimp species T. platyurus for most chemicals tested. Comparison of EC50s for fairy shrimp and EC50s for invertebrate taxa tested concurrently and with other published toxicity data indicated that fairy shrimp were relatively sensitive to potassium and several trace metals compared with other invertebrate taxa, although cladocerans, amphipods, and mussels had similar broad toxicant sensitivity. Interspecies correlation estimation models for predicting toxicity to fairy shrimp from surrogate species indicated that models with cladocerans and freshwater mussels as surrogates produced the best predictions of the sensitivity of fairy shrimp to contaminants. The results of these studies indicate that fairy shrimp are relatively sensitive to a range of toxicants, but Endangered Species Act-listed fairy shrimp of the genus Branchinecta were not consistently more sensitive than other fairy shrimp taxa. Environ Toxicol Chem

  20. Neuroecology, Chemical Defense, and the Keystone Species Concept

    National Research Council Canada - National Science Library

    Richard K. Zimmer; Ryan P. Ferrer

    2007-01-01

    .... The "keystone species" concept, for example, is seminal in ecological theory. It defines a species whose impacts on communities are far greater than would be predicted from its relative abundance and biomass...

  1. Species concepts do matter in nematology.

    Science.gov (United States)

    Ferris, V R

    1999-06-01

    Nematology is a taxon-based science, and a correct understanding of species and their relationships is basic to all nematological research. Modern methods of systematic analysis have reshaped issues concerning species recognition.

  2. Species concepts and the evolutionary paradigm in modem nematology.

    Science.gov (United States)

    Adams, B J

    1998-03-01

    Given the task of recovering and representing evolutionary history, nematode taxonomists can choose from among several species concepts. All species concepts have theoretical and (or) operational inconsistencies that can result in failure to accurately recover and represent species. This failure not only obfuscates nematode taxonomy but hinders other research programs in hematology that are dependent upon a phylogenetically correct taxonomy, such as biodiversity, biogeography, cospeciation, coevolution, and adaptation. Three types of systematic errors inherent in different species concepts and their potential effects on these research programs are presented. These errors include overestimating and underestimating the number of species (type I and II error, respectively) and misrepresenting their phylogenetic relationships (type III error). For research programs in hematology that utilize recovered evolutionary history, type II and III errors are the most serious. Linnean, biological, evolutionary, and phylogenefic species concepts are evaluated based on their sensitivity to systematic error. Linnean and biological species concepts are more prone to serious systematic error than evolutionary or phylogenetic concepts. As an alternative to the current paradigm, an amalgamation of evolutionary and phylogenetic species concepts is advocated, along with a set of discovery operations designed to minimize the risk of making systematic errors. Examples of these operations are applied to species and isolates of Heterorhabditis.

  3. Landscape genetics informs mesohabitat preference and conservation priorities for a surrogate indicator species in a highly fragmented river system.

    Science.gov (United States)

    Lean, J; Hammer, M P; Unmack, P J; Adams, M; Beheregaray, L B

    2017-04-01

    Poor dispersal species represent conservative benchmarks for biodiversity management because they provide insights into ecological processes influenced by habitat fragmentation that are less evident in more dispersive organisms. Here we used the poorly dispersive and threatened river blackfish (Gadopsis marmoratus) as a surrogate indicator system for assessing the effects of fragmentation in highly modified river basins and for prioritizing basin-wide management strategies. We combined individual, population and landscape-based approaches to analyze genetic variation in samples spanning the distribution of the species in Australia's Murray-Darling Basin, one of the world's most degraded freshwater systems. Our results indicate that G. marmoratus displays the hallmark of severe habitat fragmentation with notably scattered, small and demographically isolated populations with very low genetic diversity-a pattern found not only between regions and catchments but also between streams within catchments. By using hierarchically nested population sampling and assessing relationships between genetic uniqueness and genetic diversity across populations, we developed a spatial management framework that includes the selection of populations in need of genetic rescue. Landscape genetics provided an environmental criterion to identify associations between landscape features and ecological processes. Our results further our understanding of the impact that habitat quality and quantity has on habitat specialists with similarly low dispersal. They should also have practical applications for prioritizing both large- and small-scale conservation management actions for organisms inhabiting highly fragmented ecosystems.

  4. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms.

    Science.gov (United States)

    Carstens, Keri; Cayabyab, Bonifacio; De Schrijver, Adinda; Gadaleta, Patricia G; Hellmich, Richard L; Romeis, Jörg; Storer, Nicholas; Valicente, Fernando H; Wach, Michael

    2014-01-01

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs are assessed using surrogate species, and it is critical that the data derived from surrogates accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. The key is to select surrogate species that best represent the valued NTOs in the location where the crop is going to be introduced, but this selection process poses numerous challenges for the developers of GE crops who will perform the tests, as well as for the ecologists and regulators who will interpret the test results. These issues were the subject of a conference "Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms" convened by the Center for Environmental Risk Assessment, ILSI Research Foundation. This report summarizes the proceedings of the conference, including the presentations, discussions and the points of consensus agreed to by the participants.

  5. Effects of herbicides on Behr's metalmark butterfly, a surrogate species for the endangered butterfly, Lange's metalmark.

    Science.gov (United States)

    Stark, John D; Chen, Xue Dong; Johnson, Catherine S

    2012-05-01

    Lange's metalmark butterfly, Apodemia mormo langei Comstock, is in danger of extinction due to loss of habitat caused by invasive exotic plants which are eliminating its food, naked stem buckwheat. Herbicides are being used to remove invasive weeds from the dunes; however, little is known about the potential effects of herbicides on butterflies. To address this concern we evaluated potential toxic effects of three herbicides on Behr's metalmark, a close relative of Lange's metalmark. First instars were exposed to recommended field rates of triclopyr, sethoxydim, and imazapyr. Life history parameters were recorded after exposure. These herbicides reduced the number of adults that emerged from pupation (24-36%). Each herbicide has a different mode of action. Therefore, we speculate that effects are due to inert ingredients or indirect effects on food plant quality. If these herbicides act the same in A. mormo langei, they may contribute to the decline of this species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Prediction of naphthenic acid species degradation by kinetic and surrogate models during the ozonation of oil sands process-affected water.

    Science.gov (United States)

    Islam, Md Shahinoor; Moreira, Jesús; Chelme-Ayala, Pamela; Gamal El-Din, Mohamed

    2014-09-15

    Oil sands process-affected water (OSPW) is a complex mixture of organic and inorganic contaminants, and suspended solids, generated by the oil sands industry during the bitumen extraction process. OSPW contains a large number of structurally diverse organic compounds, and due to variability of the water quality of different OSPW matrices, there is a need to select a group of easily measured surrogate parameters for monitoring and treatment process control. In this study, kinetic and surrogate correlation models were developed to predict the degradation of naphthenic acids (NAs) species during the ozonation of OSPW. Additionally, the speciation and distribution of classical and oxidized NA species in raw and ozonated OSPW were also examined. The structure-reactivity of NA species indicated that the reactivity of individual NA species increased as the carbon and hydrogen deficiency numbers increased. The kinetic parameters obtained in this study allowed calculating the evolution of the concentrations of the acid-extractable fraction (AEF), chemical oxygen demand (COD), and NA distributions for a given ozonation process. High correlations between the AEF and COD and NA species were found, suggesting that AEF and COD can be used as surrogate parameters to predict the degradation of NAs during the ozonation of OSPW.

  7. Quantifying the dry deposition of reactive nitrogen and sulfur containing species in remote areas using a surrogate surface analysis approach

    Science.gov (United States)

    Raymond, Heather A.; Yi, Seung-Muk; Moumen, Nadjoua; Han, YoungJi; Holsen, Thomas M.

    In this study, the fluxes of gaseous (HNO 3 and SO 2) and particulate (NO 3- and SO 42-) species were measured using two recently developed surrogate surfaces, the water surface sampler (WSS) and the knife-edge surrogate surface (KSS). Sampling was conducted in Potsdam, NY, Solomons, MD, and at a farm in upstate NY intermittently between March 2000 and August 2001. The KSS contained both Nylasorb filters and greased Mylar disks. No statistical difference was found between measured total nitrate and sulfate deposition in side-by-side experiments with two WSSs. Average total nitrate fluxes measured with the WSS and Nylasorb filter on the KSS in Potsdam, Solomons, and at the farm were 3.6, 6.2, 2.9 mg m -2 day -1 and 2.5, 6.7, 2.3 mg m -2 day -1, respectively. Solomons had the highest total nitrate flux probably due to its proximity to large urban industrialized areas including Washington, DC, and Baltimore, MD. Average gaseous HNO 3 fluxes measured with the WSS and Nylasorb filter on the KSS in Potsdam, Solomons, and at the farm (calculated by subtracting the fraction of particles deposited to the Mylar disk from the total deposition to the WSS and Nylasorb filter) were 2.4, 4.9, 1.9 mg m -2 day -1 and 1.3, 5.6, 1.3 mg m -2 day -1, respectively. In Potsdam, total nitrate deposition to the WSS was greater than to the Nylasorb filter whereas in Solomons the opposite was true. This increased flux at Solomons may be because nitrate salts were formed on the surface of the Nylasorb filter by reaction of HNO 3 with previously deposited sea salt aerosols. Average p-NO 3- fluxes to the greased Mylar for the three sampling sites were 1.3, 1.3, and 1.0 mg m -2 day -1. The measured SO 2 deposition velocity to the WSS in Potsdam and Solomons was 2.1 and 1.5 cm s -1, respectively, and agreed well with other studies. The deposition velocity for HNO 3 to the WSS measured in Potsdam (8.1 cm s -1) was greater than to the Nylasorb filter (4.6 cm s -1) whereas in Solomons the opposite

  8. Birds as biodiversity surrogates

    DEFF Research Database (Denmark)

    Larsen, Frank Wugt; Bladt, Jesper Stentoft; Balmford, Andrew

    2012-01-01

    1. Most biodiversity is still unknown, and therefore, priority areas for conservation typically are identified based on the presence of surrogates, or indicator groups. Birds are commonly used as surrogates of biodiversity owing to the wide availability of relevant data and their broad popular...... appeal. However, some studies have found birds to perform relatively poorly as indicators. We therefore ask how the effectiveness of this approach can be improved by supplementing data on birds with information on other taxa. 2. Here, we explore two strategies using (i) species data for other taxa...... areas identified on the basis of birds alone performed well in representing overall species diversity where birds were relatively speciose compared to the other taxa in the data sets. Adding species data for one taxon increased surrogate effectiveness better than adding genus- and family-level data...

  9. The species concept as an emergent property of population biology.

    Science.gov (United States)

    Hart, Michael W

    2011-03-01

    Resurgent interest in the genetics of population divergence and speciation coincides with recent critical evaluation of species concepts and proposals for species delimitation. An important result of these parallel trends is a slight but important conceptual shift in focus away from species diagnoses based on prior species concepts or definitions, and toward analyses of the processes acting on lineages of metapopulations that eventually lead to differences recognizable as species taxa. An advantage of this approach is that it identifies quantitative metapopulation differences in continuous variables, rather than discrete entities that do or do not conform to a prior species concept, and species taxa are recognized as an emergent property of population-level processes. The tension between species concepts and diagnosis versus emergent recognition of species taxa is at least as old as Darwin, and is unlikely to be resolved soon in favor of either view, because the products of both approaches (discrete utilitarian taxon names for species, process-based understanding of the origins of differentiated metapopulations) continue to have important applications.

  10. Acute toxicity of six freshwater mussel species (Glochidia) to six chemicals: Implications for daphnids and Utterbackia imbecillis as surrogates for protection of freshwater mussels (Unionidae)

    Science.gov (United States)

    Milam, C.D.; Farris, J.L.; Dwyer, F.J.; Hardesty, D.K.

    2005-01-01

    Acute (24-h) toxicity tests were used in this study to compare lethality responses in early life stages (glochidia) of six freshwater mussel species, Leptodea fragilis, U. imbecillis, Lampsilis cardium, Lampsilis siliquoidea, Megalonaias nervosa, and Ligumia subrostrata, and two standard test organisms, Ceriodaphnia dubia and Daphnia magna. Concentrations of carbaryl, copper, 4-nonylphenol, pentachlorophenol, permethrin, and 2,4-D were used in acute exposures to represent different chemical classes and modes of action. The relative sensitivities of species were evaluated by ranking their LC 50 values for each chemical. We used these ranks to determine the extent to which U. imbecillis (one of the most commonly used unionids in toxicity tests) was representative of the tolerances of other mussels. We also calculated geometric mean LC50s for the families Unionidae and Daphnidae. Rankings of these data were used to assess the extent to which Daphnidae can be used as surrogates for freshwater mussels relative to chemical sensitivity. While no single chemical elicited consistently high or low toxicity estimates, carbaryl and 2,4-D were generally the least toxic to all species tested. No species was always the most sensitive, and Daphnidae were generally protective of Unionidae. Utterbackia imbecillis, while often proposed as a standard unionid mussel test species, did not always qualify as a sufficient surrogate (i.e., a substitute organism that often elicits similar sensitivity responses to the same contaminant exposure) for other species of mussels, since it was usually one of the more tolerant species in our rankings. U. imbecillis should be used as a surrogate species only with this caution on its relative insensitivity. ?? 2005 Springer Science+Business Media, Inc.

  11. Linking Keystone Species and Functional Groups: A New Operational Definition of the Keystone Species Concept

    Directory of Open Access Journals (Sweden)

    Robert D. Davic

    2003-07-01

    Full Text Available The concept of the "keystone species" is redefined to allow for the a priori prediction of these species within ecosystems. A keystone species is held to be a strongly interacting species whose top-down effect on species diversity and competition is large relative to its biomass dominance within a functional group. This operational definition links the community importance of keystone species to a specific ecosystem process, e.g., the regulation of species diversity, within functional groups at lower trophic levels that are structured by competition for a limited resource. The a priori prediction of keystone species has applied value for the conservation of natural areas.

  12. Revisiting algorithms for generating surrogate time series

    CERN Document Server

    Raeth, C; Papadakis, I E; Brinkmann, W

    2011-01-01

    The method of surrogates is one of the key concepts of nonlinear data analysis. Here, we demonstrate that commonly used algorithms for generating surrogates often fail to generate truly linear time series. Rather, they create surrogate realizations with Fourier phase correlations leading to non-detections of nonlinearities. We argue that reliable surrogates can only be generated, if one tests separately for static and dynamic nonlinearities.

  13. Combustion Kinetic Studies of Gasolines and Surrogates

    KAUST Repository

    Javed, Tamour

    2016-11-01

    Future thrusts for gasoline engine development can be broadly summarized into two categories: (i) efficiency improvements in conventional spark ignition engines, and (ii) development of advance compression ignition (ACI) concepts. Efficiency improvements in conventional spark ignition engines requires downsizing (and turbocharging) which may be achieved by using high octane gasolines, whereas, low octane gasolines fuels are anticipated for ACI concepts. The current work provides the essential combustion kinetic data, targeting both thrusts, that is needed to develop high fidelity gasoline surrogate mechanisms and surrogate complexity guidelines. Ignition delay times of a wide range of certified gasolines and surrogates are reported here. These measurements were performed in shock tubes and rapid compression machines over a wide range of experimental conditions (650 – 1250 K, 10 – 40 bar) relevant to internal combustion engines. Using the measured the data and chemical kinetic analyses, the surrogate complexity requirements for these gasolines in homogeneous environments are specified. For the discussions presented here, gasolines are classified into three categories: (i)\\tLow octane gasolines including Saudi Aramco’s light naphtha fuel (anti-knock index, AKI = (RON + MON)/2 = 64; Sensitivity (S) = RON – MON = 1), certified FACE (Fuels for Advanced Combustion Engines) gasoline I and J (AKI ~ 70, S = 0.7 and 3 respectively), and their Primary Reference Fuels (PRF, mixtures of n-heptane and iso-octane) and multi-component surrogates. (ii)\\t Mid octane gasolines including FACE A and C (AKI ~ 84, S ~ 0 and 1 respectively) and their PRF surrogates. Laser absorption measurements of intermediate and product species formed during gasoline/surrogate oxidation are also reported. (iii)\\t A wide range of n-heptane/iso-octane/toluene (TPRF) blends to adequately represent the octane and sensitivity requirements of high octane gasolines including FACE gasoline F and G

  14. Interpretation of the biological species concept from interspecific hybridization of two Helicoverpa species

    Institute of Scientific and Technical Information of China (English)

    WANG ChenZhu

    2007-01-01

    The biological species concept defines species in terms of interbreeding. Interbreeding between species is prevented by reproductive isolation mechanisms. Based on our results of interspecific hybridization between Helicoverpa armigera and Helicoverpa assulta, reproductive isolation mechanisms of the two species are analyzed. A combination of prezygotic factors (absent sex attraction and physical incompatibility of the genitalia) and postzygotic factors (female absence and partial sterility in F1 hybrids) causes reproductive isolation of the two species. In addition, the role of interspecific hybridization in speciation is discussed.

  15. The application of species criteria in avian taxonomy and its implications for the debate over species concepts.

    Science.gov (United States)

    Sangster, George

    2014-02-01

    The debate over species concepts has produced a huge body of literature on how species can, may or should be delimited. By contrast, very few studies have documented how species taxa are delimited in practice. The aims of the present study were to (i) quantify the use of species criteria in taxonomy, (ii) discuss its implications for the debate over species concepts and (iii) assess recent claims about the impact of different species concepts on taxonomic stability and the 'nature' of species. The application of six species criteria was examined in taxonomic studies of birds published between 1950 and 2009. Three types of taxonomic studies were included: descriptions of new species (N = 329), proposals to change the taxonomic rank of species and subspecies (N = 808) and the taxonomic recommendations of the American Ornithologists' Union Committee on Classification and Nomenclature (N = 176). In all three datasets, diagnosability was the most frequently applied criterion, followed by reproductive isolation and degree of difference. This result is inconsistent with the popular notion that the Biological Species Concept is the dominant species concept in avian taxonomy. Since the 1950s, avian species-level taxonomy has become increasingly pluralistic and eclectic. This suggests that taxonomists consider different criteria as complementary rather than as rival approaches to species delimitation. Application of diagnosability more frequently led to the elevation of subspecies to species rank than application of reproductive isolation, although the difference was small. Hypotheses based on diagnosability and reproductive isolation were equally likely to be accepted in a mainstream checklist. These findings contradict recent claims that application of the Phylogenetic Species Concept causes instability and that broader application of the Biological Species Concept can stabilise taxonomy. The criteria diagnosability and monophyly, which are commonly associated

  16. Putting the biological species concept to the test: using mating networks to delimit species.

    Directory of Open Access Journals (Sweden)

    Lélia Lagache

    Full Text Available Although interfertility is the key criterion upon which Mayr's biological species concept is based, it has never been applied directly to delimit species under natural conditions. Our study fills this gap. We used the interfertility criterion to delimit two closely related oak species in a forest stand by analyzing the network of natural mating events between individuals. The results reveal two groups of interfertile individuals connected by only few mating events. These two groups were largely congruent with those determined using other criteria (morphological similarity, genotypic similarity and individual relatedness. Our study, therefore, shows that the analysis of mating networks is an effective method to delimit species based on the interfertility criterion, provided that adequate network data can be assembled. Our study also shows that although species boundaries are highly congruent across methods of species delimitation, they are not exactly the same. Most of the differences stem from assignment of individuals to an intermediate category. The discrepancies between methods may reflect a biological reality. Indeed, the interfertility criterion is an environment-dependant criterion as species abundances typically affect rates of hybridization under natural conditions. Thus, the methods of species delimitation based on the interfertility criterion are expected to give results slightly different from those based on environment-independent criteria (such as the genotypic similarity criteria. However, whatever the criterion chosen, the challenge we face when delimiting species is to summarize continuous but non-uniform variations in biological diversity. The grade of membership model that we use in this study appears as an appropriate tool.

  17. The Reactive Sulfur Species Concept: 15 Years On

    Science.gov (United States)

    Giles, Gregory I.; Nasim, Muhammad Jawad; Ali, Wesam; Jacob, Claus

    2017-01-01

    Fifteen years ago, in 2001, the concept of “Reactive Sulfur Species” or RSS was advocated as a working hypothesis. Since then various organic as well as inorganic RSS have attracted considerable interest and stimulated many new and often unexpected avenues in research and product development. During this time, it has become apparent that molecules with sulfur-containing functional groups are not just the passive “victims” of oxidative stress or simple conveyors of signals in cells, but can also be stressors in their own right, with pivotal roles in cellular function and homeostasis. Many “exotic” sulfur-based compounds, often of natural origin, have entered the fray in the context of nutrition, ageing, chemoprevention and therapy. In parallel, the field of inorganic RSS has come to the forefront of research, with short-lived yet metabolically important intermediates, such as various sulfur-nitrogen species and polysulfides (Sx2−), playing important roles. Between 2003 and 2005 several breath-taking discoveries emerged characterising unusual sulfur redox states in biology, and since then the truly unique role of sulfur-dependent redox systems has become apparent. Following these discoveries, over the last decade a “hunt” and, more recently, mining for such modifications has begun—and still continues—often in conjunction with new, innovative and complex labelling and analytical methods to capture the (entire) sulfur “redoxome”. A key distinction for RSS is that, unlike oxygen or nitrogen, sulfur not only forms a plethora of specific reactive species, but sulfur also targets itself, as sulfur containing molecules, i.e., peptides, proteins and enzymes, preferentially react with RSS. Not surprisingly, today this sulfur-centred redox signalling and control inside the living cell is a burning issue, which has moved on from the predominantly thiol/disulfide biochemistry of the past to a complex labyrinth of interacting signalling and control

  18. Species concepts and biodiversity in Trichoderma and Hypocrea: from aggregate species to species clusters?

    Institute of Scientific and Technical Information of China (English)

    DRUZHININA Irina; KUBICEK Christian P.

    2005-01-01

    Trichoderma/Hypocrea is a genus of soil-borne or wood-decaying fungi containing members important to mankind as producers of industrial enzymes and biocontrol agents against plant pathogens, but also as opportunistic pathogens of immunocompromised humans. Species identification, while essential in view of the controversial properties of taxa ofthis genus, has been problematic by traditional methods. Here we will present a critical survey of the various identification methods in use. In addition,we will present an update on the taxonomy and phylogeny of the 88 taxa (which occur as 14 holomorphs, 49 teleomorphs and 25 anamorphs in nature) of Trichoderma/Hypocrea that have been confirmed by a combination of morphological, physiological and genetic approaches.

  19. Empathy and alteration: the ethical relevance of a phenomenological species concept.

    Science.gov (United States)

    Meacham, Darian

    2014-10-01

    The debate over the ethics of radically, technologically altering the capacities and traditional form of the human body is rife with appeals to and dismissals of the importance of the integrity of the human species. Species-integrist arguments can be found in authors as varied as Annas, Fukuyama, Habermas, and Agar. However, the ethical salience of species integrity is widely contested by authors such as Buchanan, Daniels, Fenton, and Juengst. This article proposes a Phenomenological approach to the question of species-integrity, arguing in favor of a phenomenon of species-recognition that carries an ethical pull. Building on Husserl's Phenomenological account of empathy and the lived-body, as well as Schopenhauer's concept of compassion as an ethical urphenomenon, I develop a "Phenomenological species concept" (PSC), which I argue has the ethical significance that biological species concepts do not. The PSC reorients the debate over human alteration and species integrity.

  20. Applying surrogate species presences to correct sample bias in species distribution models: a case study using the Pilbara population of the Northern Quoll

    Directory of Open Access Journals (Sweden)

    Shaun W. Molloy

    2017-05-01

    Full Text Available The management of populations of threatened species requires the capacity to identify areas of high habitat value. We developed a high resolution species distribution model (SDM for the endangered Pilbara northern quoll Dasyurus hallucatus, population using MaxEnt software and a combined suite of bioclimatic and landscape variables. Once common throughout much of northern Australia, this marsupial carnivore has recently declined throughout much of its former range and is listed as endangered by the IUCN. Other than the potential threats presented by climate change, and the invasive cane toad Rhinella marina (which has not yet arrived in the Pilbara. The Pilbara population is also impacted by introduced predators, pastoral and mining activities. To account for sample bias resulting from targeted surveys unevenly spread through the region, a pseudo-absence bias layer was developed from presence records of other critical weight-range non-volant mammals. The resulting model was then tested using the biomod2 package which produces ensemble models from individual models created with different algorithms. This ensemble model supported the distribution determined by the bias compensated MaxEnt model with a covariance of of 86% between models with both models largely identifying the same areas as high priority habitat. The primary product of this exercise is a high resolution SDM which corroborates and elaborates on our understanding of the ecology and habitat preferences of the Pilbara Northern Quoll population thereby improving our capacity to manage this population in the face of future threats.

  1. Species concepts in Cercospora: spotting the weeds among the roses

    NARCIS (Netherlands)

    Groenewald, J.Z.; Nakashima, C.; Nishikawa, J.; Shin, H.D.; Park, J.H.; Jama, A.N.; Groenewald, M.; Braun, U.; Crous, P.W.

    2013-01-01

    The genus Cercospora contains numerous important plant pathogenic fungi from a diverse range of hosts. Most species of Cercospora are known only from their morphological characters in vivo. Although the genus contains more than 5 000 names, very few cultures and associated DNA sequence data are avai

  2. The species concept as a cognitive tool for biological anthropology.

    Science.gov (United States)

    Bruner, Emiliano

    2013-01-01

    Taxonomy is caught between the search for the "perfect" theory and an elusive biological variability. The lack of major advances in issues related to how "species" and other taxonomic categories are defined suggests that perhaps we should avoid excessively rigid formalism in this regard. The risk is a separation between elegant but useless theories and confusing applications of the taxonomic tools. Communication is one of the main functions of taxonomy, and stability one of the main parameters that taxonomy users should be sensitive to. An excess of stability may generate anachronistic consequences while continuous revisions may make the tool of taxonomy scarcely practical. The current tendency pushes toward more and more fragmentation of biologically valid taxa. While taxonomy specialists enjoy such challenges, many taxonomy users feel a bit nervous and discouraged when trying to use a tool that is constantly changing. Debates over taxonomy would seem particularly unrewarding for fields with limited samples and scarce biological diversity, such as palaeoanthropology. In this context, where the information available is rarely sufficient to supply consistent taxonomical evidence, there are frequently excessive efforts to create debate on species separations. The risk is that we maintain the debate on a purely theoretical level, or else we distrust a reliable use of taxonomy. A compromise (and recommended) choice between these two extremes would be to rely on shared and reasonable interpretations of homogeneous evolutionary units, without diving into fine-grained issues that will remain, however, unresolved. Taxonomy should be a tool, not the goal, of the evolutionary biologist. Our mind needs discrete and recognizable objects to structure our perception of reality. There is no reason to expect that nature works the same way.

  3. The median means of species concepts and species delimitation%物种概念及其界定

    Institute of Scientific and Technical Information of China (English)

    龚佐山; 买买提明·苏来曼

    2012-01-01

    半世纪以来,物种概念的定义备受关注,不同研究方向的生物学家提出24种不同或至少有分歧的物种概念,根据其不同的物种概念,物种的界定和物种的数量会出现很大的差异.人们普遍认同:物种是进化分离的微居群谱系,但把谱系分离过程中获得的特征如生殖隔离、可鉴定性、单系统发生等视为鉴定物种次级特征却有不同的声音.该文提出统一的物种概念,把谱系进化分离作为物种界定的唯一而又必要的特征,把谱系分离过程中获得的次级特征作为界定谱系分离的证据.鉴于此,物种概念间的分歧就会化解.其一,物种概念化与物种界定明显分开,不再混淆;其二,谱系的次级特征只与物种界定有关,在某种程度上为谱系分离提供证据;第三,若能把合理解释的任何一个特征作为某物种客观存在的证据,这样更多的特征更能确定谱系分离;最后最重要的是,统一物种概念使我们解放思想,扬弃传统的物种界定标准,探求物种界定的新思路.%From the half century to now,the issue of species delimitation has long been confused by species conceptu alization, according to controversy species concepts,the boundaries and numbers of species could be great difference. Alternative species concepts agree in treating existence as a separately evolving metapopulation lineage as the primary defining property of the species category, but adopting different properties acquired by lineages during the course of divergence(e. G. Intrinsic reproductive isolation,diagnosability,monophyly)as secondary species criteria causes differ ent sounds. The paper gave a unified species concept treating a separately evolving metapopulation lineage as the only necessary property of species,and secondary species criteria as different lines of evidence relevant to assessing lineage separation. This unified concept of species had several consequences for species delimitation as

  4. Make the Most of the Data You've Got: Bayesian Models and a Surrogate Species Approach to Assessing Benefits of Upstream Migration Flows for the Endangered Australian Grayling.

    Science.gov (United States)

    Webb, J Angus; Koster, Wayne M; Stuart, Ivor G; Reich, Paul; Stewardson, Michael J

    2017-03-03

    Environmental water managers must make best use of allocations, and adaptive management is one means of improving effectiveness of environmental water delivery. Adaptive management relies on generation of new knowledge from monitoring and evaluation, but it is often difficult to make clear inferences from available monitoring data. Alternative approaches to assessment of flow benefits may offer an improved pathway to adaptive management. We developed Bayesian statistical models to inform adaptive management of the threatened Australian grayling (Prototroctes maraena) in the coastal Thomson River, South-East Victoria Australia. The models assessed the importance of flows in spring and early summer (migration flows) for upstream dispersal and colonization of juveniles of this diadromous species. However, Australian grayling young-of-year were recorded in low numbers, and models provided no indication of the benefit of migration flows. To overcome this limitation, we applied the same models to young-of-year of a surrogate species (tupong-Pseudaphritis urvilli)-a more common diadromous species expected to respond to flow similarly to Australian grayling-and found strong positive responses to migration flows. Our results suggest two complementary approaches to supporting adaptive management of Australian grayling. First, refine monitoring approaches to allow direct measurement of effects of migration flows, a process currently under way. Second, while waiting for improved data, further investigate the use of tupong as a surrogate species. More generally, alternative approaches to assessment can improve knowledge to inform adaptive management, and this can occur while monitoring is being revised to directly target environmental responses of interest.

  5. Plutonium radiation surrogate

    Science.gov (United States)

    Frank, Michael I [Dublin, CA

    2010-02-02

    A self-contained source of gamma-ray and neutron radiation suitable for use as a radiation surrogate for weapons-grade plutonium is described. The source generates a radiation spectrum similar to that of weapons-grade plutonium at 5% energy resolution between 59 and 2614 keV, but contains no special nuclear material and emits little .alpha.-particle radiation. The weapons-grade plutonium radiation surrogate also emits neutrons having fluxes commensurate with the gamma-radiation intensities employed.

  6. Strain, clone and species : comments on three basic concepts of bacteriology

    NARCIS (Netherlands)

    Ursing, BM; Ursing, JB

    2000-01-01

    Different aspects of the terms strain, clone and species are discussed. The term strain is commonly used to denote a pure culture - here called 'the strain in the taxonomic sense' - but does also refer to a natural concept closely related to the clone. The term clone on the other hand is used both i

  7. Third-Graders' Conceptions about the Origin of Species before and after Instruction: An Exploratory Study

    Science.gov (United States)

    Berti, Anna Emilia; Barbetta, Valentina; Toneatti, Laura

    2017-01-01

    This study examines how third-graders' conceptions about the origin of species are affected by formal instruction and whether children can learn not only about evolution but also about natural selection. We interviewed the same group of third-grade children (8-9 years old) twice, before and after following a curriculum about these topics.…

  8. Third-Graders' Conceptions about the Origin of Species before and after Instruction: An Exploratory Study

    Science.gov (United States)

    Berti, Anna Emilia; Barbetta, Valentina; Toneatti, Laura

    2017-01-01

    This study examines how third-graders' conceptions about the origin of species are affected by formal instruction and whether children can learn not only about evolution but also about natural selection. We interviewed the same group of third-grade children (8-9 years old) twice, before and after following a curriculum about these topics.…

  9. Ditch the niche - is the niche a useful concept in ecology or species distribution modelling?

    NARCIS (Netherlands)

    McInerny, Greg J.; Etienne, Rampal S.

    2012-01-01

    In this first of three papers we examine the use of niche concepts in ecology and especially in species distribution modelling (SDM). This paper deliberately focuses on the lack of clarity found in the term niche. Because its meanings are so diverse, the term niche tends to create confusion and

  10. Developments in Surrogating Methods

    Directory of Open Access Journals (Sweden)

    Hans van Dormolen

    2005-11-01

    Full Text Available In this paper, I would like to talk about the developments in surrogating methods for preservation. My main focus will be on the technical aspects of preservation surrogates. This means that I will tell you something about my job as Quality Manager Microfilming for the Netherlands’ national preservation program, Metamorfoze, which is coordinated by the National Library. I am responsible for the quality of the preservation microfilms, which are produced for Metamorfoze. Firstly, I will elaborate on developments in preservation methods in relation to the following subjects: · Preservation microfilms · Scanning of preservation microfilms · Preservation scanning · Computer Output Microfilm. In the closing paragraphs of this paper, I would like to tell you something about the methylene blue test. This is an important test for long-term storage of preservation microfilms. Also, I will give you a brief report on the Cellulose Acetate Microfilm Conference that was held in the British Library in London, May 2005.

  11. Priority wetland invertebrates as conservation surrogates.

    Science.gov (United States)

    Ormerod, S J; Durance, Isabelle; Terrier, Aurelie; Swanson, Alisa M

    2010-04-01

    Invertebrates are important functionally in most ecosystems, but seldom appraised as surrogate indicators of biological diversity. Priority species might be good candidates; thus, here we evaluated whether three freshwater invertebrates listed in the U.K. Biodiversity Action Plan indicated the richness, composition, and conservation importance of associated wetland organisms as defined respectively by their alpha diversity, beta diversity, and threat status. Sites occupied by each of the gastropods Segmentina nitida, Anisus vorticulus, and Valvata macrostoma had greater species richness of gastropods and greater conservation importance than other sites. Each also characterized species assemblages associated with significant variations between locations in alpha or beta diversity among other mollusks and aquatic macrophytes. Because of their distinct resource requirements, conserving the three priority species extended the range of wetland types under management for nature conservation by 18% and the associated gastropod niche-space by around 33%. Although nonpriority species indicated variations in richness, composition, and conservation importance among other organisms as effectively as priority species, none characterized such a wide range of high-quality wetland types. We conclude that priority invertebrates are no more effective than nonpriority species as indicators of alpha and beta diversity or conservation importance among associated organisms. Nevertheless, conserving priority species can extend the array of distinct environments that are protected for their specialized biodiversity and environmental quality. We suggest that this is a key role for priority species and conservation surrogates more generally, and, on our evidence, can best be delivered through multiple species with contrasting habitat requirements.

  12. Homologous recombination in Agrobacterium: potential implications for the genomic species concept in bacteria.

    Science.gov (United States)

    Costechareyre, Denis; Bertolla, Franck; Nesme, Xavier

    2009-01-01

    only minor declines in homologous recombination frequencies. Consequently, the sequence diversity, as a mechanistic factor for the efficiency of recombination (as assayed in the laboratory), appears to play little role in the genetic cohesion of bacterial species, and thus, the genomic species definition for prokaryotes is definitively not reconcilable with the biological species concept for eukaryotes.

  13. Surrogate motherhood as a medical treatment procedure for women's infertility.

    Science.gov (United States)

    Jovic, Olga S

    2011-03-01

    The content of this work is conceived on the research of the consequences of surrogate motherhood as a process of assisted procreation, which represent a way of parenthood in cases when it is not possible to realize parenthood through a natural way. Surrogate motherhood is a process in which a woman (surrogate mother) agrees to carry a pregnancy with the intent to give the child to the couple with whom she has made a contract on surrogate maternity after the birth. This process of conception and birth makes the determination of the child's origin on its mother's side hard to determine, because of the distinction of the genetic and gestation phases of the two women. The concept of surrogate motherhood is to appear in two forms, depending on the existence or the non-existence of the genetic link between the surrogate mother and the child she gives birth to. There are gestation (full) and genetic (partial) surrogates each with different modalities and legal and ethical implications. In Serbia, Infertility Treatment and the Bio-medically Assisted Procreation Act from 2009 explicitly forbids surrogate motherhood, despite the fact that an infertile couple decides to use it, as a rule, after having tried all other treatment procedures, in cases when there is a diagnosis but the conventional treatment applied has not produced the desired results. Given the fact that no one has the right to ignore the sufferings of people who cannot procreate naturally, the medical practice and legal science in our country plead for a formulation of a legal framework in which to apply surrogate motherhood as an infertility treatment, under particular conditions.

  14. Surrogate Modeling for Geometry Optimization

    DEFF Research Database (Denmark)

    Rojas Larrazabal, Marielba de la Caridad; Abraham, Yonas; Holzwarth, Natalie;

    2009-01-01

    A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used.......A new approach for optimizing the nuclear geometry of an atomic system is described. Instead of the original expensive objective function (energy functional), a small number of simpler surrogates is used....

  15. Surrogate Endpoints in Suicide Research

    Science.gov (United States)

    Wortzel, Hal S.; Gutierrez, Peter M.; Homaifar, Beeta Y.; Breshears, Ryan E.; Harwood, Jeri E.

    2010-01-01

    Surrogate endpoints frequently substitute for rare outcomes in research. The ability to learn about completed suicides by investigating more readily available and proximate outcomes, such as suicide attempts, has obvious appeal. However, concerns with surrogates from the statistical science perspective exist, and mounting evidence from…

  16. Developing thresholds of potential concern for invasive alien species: Hypotheses and concepts

    Directory of Open Access Journals (Sweden)

    Llewellyn C. Foxcroft

    2009-01-01

    Full Text Available The Kruger National Park (KNP has developed and refined a system of management called ‘strategic adaptive management’ (SAM, which rests on the concept of ‘threshold of potential concern’ (TPC. TPCs represent end-points in a continuum of change. When thresholds are reached – at which point concerns of negative impacts on biodiversity are raised – management options are explicitly considered and implemented. This paper describes the TPCs developed for monitoring and managing invasive alien species (IAS. More importantly, however, it describes the conceptual understanding, principles and hypotheses adopted as the foundations for setting these TPCs. In accordance with adaptive management practices, the TPCs will be revised as the ecological and conceptual understanding of invasions grows and information is gained through research in the KNP and elsewhere.Conservation implication: In accepting that species and systems are variable, and that flux is inevitable and desirable, these TPCs developed for invasive alien species specifi cally, provide end points against which monitoring can be assessed. Once a threshold is reached, the cause of the threshold being exceeded is examined and management interventions recommended.

  17. Disinfection byproduct regulatory compliance surrogates and bromide-associated risk.

    Science.gov (United States)

    Kolb, Chelsea; Francis, Royce A; VanBriesen, Jeanne M

    2017-08-01

    Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. Copyright © 2017. Published by Elsevier B.V.

  18. Effectiveness of biological surrogates for predicting patterns of marine biodiversity: a global meta-analysis.

    Directory of Open Access Journals (Sweden)

    Camille Mellin

    Full Text Available The use of biological surrogates as proxies for biodiversity patterns is gaining popularity, particularly in marine systems where field surveys can be expensive and species richness high. Yet, uncertainty regarding their applicability remains because of inconsistency of definitions, a lack of standard methods for estimating effectiveness, and variable spatial scales considered. We present a Bayesian meta-analysis of the effectiveness of biological surrogates in marine ecosystems. Surrogate effectiveness was defined both as the proportion of surrogacy tests where predictions based on surrogates were better than random (i.e., low probability of making a Type I error; P and as the predictability of targets using surrogates (R(2. A total of 264 published surrogacy tests combined with prior probabilities elicited from eight international experts demonstrated that the habitat, spatial scale, type of surrogate and statistical method used all influenced surrogate effectiveness, at least according to either P or R(2. The type of surrogate used (higher-taxa, cross-taxa or subset taxa was the best predictor of P, with the higher-taxa surrogates outperforming all others. The marine habitat was the best predictor of R(2, with particularly low predictability in tropical reefs. Surrogate effectiveness was greatest for higher-taxa surrogates at a <10-km spatial scale, in low-complexity marine habitats such as soft bottoms, and using multivariate-based methods. Comparisons with terrestrial studies in terms of the methods used to study surrogates revealed that marine applications still ignore some problems with several widely used statistical approaches to surrogacy. Our study provides a benchmark for the reliable use of biological surrogates in marine ecosystems, and highlights directions for future development of biological surrogates in predicting biodiversity.

  19. Top predators: hot or not? A call for systematic assessment of biodiversity surrogates

    NARCIS (Netherlands)

    Cabeza, M.; Arponen, A.; Teeffelen, van A.J.A.

    2008-01-01

    argue that top predators are justified conservation surrogates based on a case study where raptor presence is associated with high species richness of birds, butterflies and trees. 2. We question the methodology as well as the applicability of their results, and clarify differences between surrogate

  20. [Surrogate maternity--literature review and practice].

    Science.gov (United States)

    Pilka, L; Rumpík, D; Pilka, R; Koudelka, M; Prudil, L

    2009-04-01

    This review summarizes opinions on surrogacy including internatinal and governmental organizations attitudes, as well as some religious concerns. Literature review. Reprofit International, Brno, Reproductive medicine and gynecology centre, Zlin, Department of obstetrics and gynecology, Palacky University, Olomouc. The developments in the field of assissted reproduction during the last twenty years have attracted unexpected public interest in some of its ethical and moral aspects. It is very difficult to find a uniform attitude to ethical concerns of assisted conception in plural society. Surrogate mother is defined as a woman who bears and relinquishes a child for another person. The european congress on human reproduction in Barcelona 2008 adopted following résumé on surrogacy: Public opinion has shifted to a position where surrogacy is recognized as an appropriate response to infertility in some circumstances and it is to be expected that this approach will be further strenghtened with stress on positive aspects of familiar life.

  1. Defining and evaluating the umbrella species concept for conserving and restoring landscape connectivity.

    Science.gov (United States)

    Breckheimer, Ian; Haddad, Nick M; Morris, William F; Trainor, Anne M; Fields, William R; Jobe, R Todd; Hudgens, Brian R; Moody, Aaron; Walters, Jeffrey R

    2014-12-01

    Conserving or restoring landscape connectivity between patches of breeding habitat is a common strategy to protect threatened species from habitat fragmentation. By managing connectivity for some species, usually charismatic vertebrates, it is often assumed that these species will serve as conservation umbrellas for other species. We tested this assumption by developing a quantitative method to measure overlap in dispersal habitat of 3 threatened species-a bird (the umbrella), a butterfly, and a frog-inhabiting the same fragmented landscape. Dispersal habitat was determined with Circuitscape, which was parameterized with movement data collected for each species. Despite differences in natural history and breeding habitat, we found substantial overlap in the spatial distributions of areas important for dispersal of this suite of taxa. However, the intuitive umbrella species (the bird) did not have the highest overlap with other species in terms of the areas that supported connectivity. Nevertheless, we contend that when there are no irreconcilable differences between the dispersal habitats of species that cohabitate on the landscape, managing for umbrella species can help conserve or restore connectivity simultaneously for multiple threatened species with different habitat requirements. © 2014 Society for Conservation Biology.

  2. A comparison of the application of a biological and phenetic species concept in the Hebeloma crustuliniforme complex within a phylogenetic framework

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Kuyper, T.W.

    2004-01-01

    is provided. Other taxon names are briefly discussed. The very limited ability to translate a biological species concept into an operational phenetic species concept is explained by the lack of qualitative characters and the plasticity of quantitative characters. Recency of common evolutionary history is also...

  3. Biopolicies and biotechnologies: reflections on surrogate maternity in India

    OpenAIRE

    Mónica Amador

    2010-01-01

    This article explores the impact of biotechnology, particularly on assisted reproductive technologies such as surrogate motherhood. The study is based on interviews and field work conducted in the city of Hyderabad in India within the frame of the seminar on “Research Methodology” given by Dr. Rohan D´Souza at the Centre for Studies in Science Policy at the Jawaharlal Nehru University in India. The theoretical framework of this analysis focuses on exploring concepts such as cyborg (Haraway,19...

  4. Biopolicies and biotechnologies: reflections on surrogate maternity in India

    OpenAIRE

    Mónica Amador

    2010-01-01

    This article explores the impact of biotechnology, particularly on assisted reproductive technologies such as surrogate motherhood. The study is based on interviews and field work conducted in the city of Hyderabad in India within the frame of the seminar on “Research Methodology” given by Dr. Rohan D´Souza at the Centre for Studies in Science Policy at the Jawaharlal Nehru University in India. The theoretical framework of this analysis focuses on exploring concepts such as cyborg (Haraway,19...

  5. What can comparative genomics tell us about species concepts in the genus Aspergillus?

    Energy Technology Data Exchange (ETDEWEB)

    Rokas, Antonis; payne, gary; Federova, Natalie D.; Baker, Scott E.; Machida, Masa; yu, Jiujiang; georgianna, D. R.; Dean, Ralph A.; Bhatnagar, Deepak; Cleveland, T. E.; Wortman, Jennifer R.; Maiti, R.; Joardar, V.; Amedeo, Paolo; Denning, David W.; Nierman, William C.

    2007-12-15

    Understanding the nature of species" boundaries is a fundamental question in evolutionary biology. The availability of genomes from several species of the genus Aspergillus allows us for the first time to examine the demarcation of fungal species at the whole-genome level. Here, we examine four case studies, two of which involve intraspecific comparisons, whereas the other two deal with interspecific genomic comparisons between closely related species. These four comparisons reveal significant variation in the nature of species boundaries across Aspergillus. For example, comparisons between A. fumigatus and Neosartorya fischeri (the teleomorph of A. fischerianus) and between A. oryzae and A. flavus suggest that measures of sequence similarity and species-specific genes are significantly higher for the A. fumigatus - N. fischeri pair. Importantly, the values obtained from the comparison between A. oryzae and A. flavus are remarkably similar to those obtained from an intra-specific comparison of A. fumigatus strains, giving support to the proposal that A. oryzae represents a distinct ecotype of A. flavus and not a distinct species. We argue that genomic data can aid Aspergillus taxonomy by serving as a source of novel and unprecedented amounts of comparative data, as a resource for the development of additional diagnostic tools, and finally as a knowledge database about the biological differences between strains and species.

  6. Generation Conservation: Children's Developing Folkbiological and Moral Conceptions of Protecting Endangered Species

    Science.gov (United States)

    Ruckert, Jolina H.

    2016-01-01

    Research Findings: This study investigated folkbiological concepts that structure children's moral reasoning regarding conservation. Participants (N = 52; 7- and 10-year-olds, gender balanced) were interviewed regarding their values, moral obligations, and rights concerns for endangered and extinct animals. Across the 2 ages, children drew on the…

  7. Generation Conservation: Children's Developing Folkbiological and Moral Conceptions of Protecting Endangered Species

    Science.gov (United States)

    Ruckert, Jolina H.

    2016-01-01

    Research Findings: This study investigated folkbiological concepts that structure children's moral reasoning regarding conservation. Participants (N = 52; 7- and 10-year-olds, gender balanced) were interviewed regarding their values, moral obligations, and rights concerns for endangered and extinct animals. Across the 2 ages, children drew on the…

  8. Using multiscale spatial models to assess potential surrogate habitat for an imperiled reptile.

    Directory of Open Access Journals (Sweden)

    Jennifer M Fill

    Full Text Available In evaluating conservation and management options for species, practitioners might consider surrogate habitats at multiple scales when estimating available habitat or modeling species' potential distributions based on suitable habitats, especially when native environments are rare. Species' dependence on surrogates likely increases as optimal habitat is degraded and lost due to anthropogenic landscape change, and thus surrogate habitats may be vital for an imperiled species' survival in highly modified landscapes. We used spatial habitat models to examine a potential surrogate habitat for an imperiled ambush predator (eastern diamondback rattlesnake, Crotalus adamanteus; EDB at two scales. The EDB is an apex predator indigenous to imperiled longleaf pine ecosystems (Pinus palustris of the southeastern United States. Loss of native open-canopy pine savannas and woodlands has been suggested as the principal cause of the species' extensive decline. We examined EDB habitat selection in the Coastal Plain tidewater region to evaluate the role of marsh as a potential surrogate habitat and to further quantify the species' habitat requirements at two scales: home range (HR and within the home range (WHR. We studied EDBs using radiotelemetry and employed an information-theoretic approach and logistic regression to model habitat selection as use vs.We failed to detect a positive association with marsh as a surrogate habitat at the HR scale; rather, EDBs exhibited significantly negative associations with all landscape patches except pine savanna. Within home range selection was characterized by a negative association with forest and a positive association with ground cover, which suggests that EDBs may use surrogate habitats of similar structure, including marsh, within their home ranges. While our HR analysis did not support tidal marsh as a surrogate habitat, marsh may still provide resources for EDBs at smaller scales.

  9. Toward monophyletic generic concepts in Magnaporthales: species with Harpophora asexual states.

    Science.gov (United States)

    Luo, Jing; Walsh, Emily; Zhang, Ning

    2015-01-01

    We investigated the phylogenetic relationships among Magnaporthales fungi with harpophora-like asexual states based on DNA sequences of ITS, MCM7, RPB1 and TEF1 genes. The results indicated that these species are polyphyletic. Based on the four-gene phylogeny, the type species of Harpophora, H. radicicola, belongs to Gaeumannomyces and thus Harpophora is treated as a synonym of Gaeumannomyces. In addition, a monotypic new genus, Falciphora, is established based on F. oryzae, previous referred as Harpophora oryzae.

  10. A comparison of the application of a biological and morphological species concept in the Hebeloma crustuliniforme complex within a phylogenetic framework

    NARCIS (Netherlands)

    Aanen, D.K.; Kuyper, T.W.

    2004-01-01

    A method is presented to derive an operational phenetic species concept for the Hebeloma crustuliniforme complex in northwestern Europe. The complex was found to consist of at least 22 biological species (intercompatibility groups; ICGs). Almost none of these biological species could be recognised

  11. A comparison of the application of a biological and phenetic species concept in the Hebeloma crustuliniforme complex within a phylogenetic framework

    NARCIS (Netherlands)

    Aanen, Duur K.; Kuyper, Thomas W.

    2004-01-01

    A method is presented to derive an operational phenetic species concept for the Hebeloma crustuliniforme complex in northwestern Europe. The complex was found to consist of at least 22 biological species (intercompatibility groups; ICGs). Almost none of these biological species could be recognised

  12. Surrogate Analysis and Index Developer (SAID) tool

    Science.gov (United States)

    Domanski, Marian M.; Straub, Timothy D.; Landers, Mark N.

    2015-10-01

    The use of acoustic and other parameters as surrogates for suspended-sediment concentrations (SSC) in rivers has been successful in multiple applications across the Nation. Tools to process and evaluate the data are critical to advancing the operational use of surrogates along with the subsequent development of regression models from which real-time sediment concentrations can be made available to the public. Recent developments in both areas are having an immediate impact on surrogate research and on surrogate monitoring sites currently (2015) in operation.

  13. Very Short Literature Survey From Supervised Learning To Surrogate Modeling

    CERN Document Server

    Brusan, Altay

    2012-01-01

    The past century was era of linear systems. Either systems (especially industrial ones) were simple (quasi)linear or linear approximations were accurate enough. In addition, just at the ending decades of the century profusion of computing devices were available, before then due to lack of computational resources it was not easy to evaluate available nonlinear system studies. At the moment both these two conditions changed, systems are highly complex and also pervasive amount of computation strength is cheap and easy to achieve. For recent era, a new branch of supervised learning well known as surrogate modeling (meta-modeling, surface modeling) has been devised which aimed at answering new needs of modeling realm. This short literature survey is on to introduce surrogate modeling to whom is familiar with the concepts of supervised learning. Necessity, challenges and visions of the topic are considered.

  14. A computational methodology for formulating gasoline surrogate fuels with accurate physical and chemical kinetic properties

    KAUST Repository

    Ahmed, Ahfaz

    2015-03-01

    Gasoline is the most widely used fuel for light duty automobile transportation, but its molecular complexity makes it intractable to experimentally and computationally study the fundamental combustion properties. Therefore, surrogate fuels with a simpler molecular composition that represent real fuel behavior in one or more aspects are needed to enable repeatable experimental and computational combustion investigations. This study presents a novel computational methodology for formulating surrogates for FACE (fuels for advanced combustion engines) gasolines A and C by combining regression modeling with physical and chemical kinetics simulations. The computational methodology integrates simulation tools executed across different software platforms. Initially, the palette of surrogate species and carbon types for the target fuels were determined from a detailed hydrocarbon analysis (DHA). A regression algorithm implemented in MATLAB was linked to REFPROP for simulation of distillation curves and calculation of physical properties of surrogate compositions. The MATLAB code generates a surrogate composition at each iteration, which is then used to automatically generate CHEMKIN input files that are submitted to homogeneous batch reactor simulations for prediction of research octane number (RON). The regression algorithm determines the optimal surrogate composition to match the fuel properties of FACE A and C gasoline, specifically hydrogen/carbon (H/C) ratio, density, distillation characteristics, carbon types, and RON. The optimal surrogate fuel compositions obtained using the present computational approach was compared to the real fuel properties, as well as with surrogate compositions available in the literature. Experiments were conducted within a Cooperative Fuels Research (CFR) engine operating under controlled autoignition (CAI) mode to compare the formulated surrogates against the real fuels. Carbon monoxide measurements indicated that the proposed surrogates

  15. Broadband chemical species tomography: Measurement theory and a proof-of-concept emission detection experiment

    Science.gov (United States)

    Grauer, Samuel J.; Tsang, Roger W.; Daun, Kyle J.

    2017-09-01

    This work introduces broadband-absorption based chemical species tomography (CST) as a novel approach to reconstruct hydrocarbon concentrations from open-path attenuation measurements. In contrast to monochromatic CST, which usually involves solving a mathematically ill-posed linear problem, the measurement equations in broadband CST are nonlinear due to the integration of the radiative transfer equation over the detection spectrum. We present a transfer function that relates broadband transmittances to a path-integrated concentration, suitable for tomographic reconstruction, and use a Bayesian reconstruction technique that combines the measurement data with a priori assumptions about the spatial distribution of the target species. The technique is demonstrated by reconstructing a propane plume, and validating the results by point concentration measurements made with a flame ionization detector.

  16. Genomics and transcriptomics of Xanthomonas campestris species challenge the concept of core type III effectome.

    Science.gov (United States)

    Roux, Brice; Bolot, Stéphanie; Guy, Endrick; Denancé, Nicolas; Lautier, Martine; Jardinaud, Marie-Françoise; Fischer-Le Saux, Marion; Portier, Perrine; Jacques, Marie-Agnès; Gagnevin, Lionel; Pruvost, Olivier; Lauber, Emmanuelle; Arlat, Matthieu; Carrère, Sébastien; Koebnik, Ralf; Noël, Laurent D

    2015-11-18

    The bacterial species Xanthomonas campestris infects a wide range of Brassicaceae. Specific pathovars of this species cause black rot (pv. campestris), bacterial blight of stock (pv. incanae) or bacterial leaf spot (pv. raphani). In this study, we extended the genomic coverage of the species by sequencing and annotating the genomes of strains from pathovar incanae (CFBP 1606R and CFBP 2527R), pathovar raphani (CFBP 5828R) and a pathovar formerly named barbareae (CFBP 5825R). While comparative analyses identified a large core ORFeome at the species level, the core type III effectome was limited to only three putative type III effectors (XopP, XopF1 and XopAL1). In Xanthomonas, these effector proteins are injected inside the plant cells by the type III secretion system and contribute collectively to virulence. A deep and strand-specific RNA sequencing strategy was adopted in order to experimentally refine genome annotation for strain CFBP 5828R. This approach also allowed the experimental definition of novel ORFs and non-coding RNA transcripts. Using a constitutively active allele of hrpG, a master regulator of the type III secretion system, a HrpG-dependent regulon of 141 genes co-regulated with the type III secretion system was identified. Importantly, all these genes but seven are positively regulated by HrpG and 56 of those encode components of the Hrp type III secretion system and putative effector proteins. This dataset is an important resource to mine for novel type III effector proteins as well as for bacterial genes which could contribute to pathogenicity of X. campestris.

  17. Solar Occultation Constellation for Retrieving Aerosols and Trace Element Species (SOCRATES): Proposed Mission Concept

    Science.gov (United States)

    Gordley, L. L.; Bailey, S. M.

    2015-12-01

    The goal of SOCRATES is to resolve the critical but underexplored role of the upper troposphere/lower stratosphere (UTLS) in climate change. The mission would provide the suite of measurements required to quantify UTLS transport pathways and their contribution to UTLS composition, and to evaluate the radiative forcing implications of changes in UTLS composition forced by expected changes in these pathways as the climate evolves. The discrimination and quantification of UTLS transport pathways requires simultaneous measurement of several key trace gases and aerosols with high precision, accuracy, and vertical resolution. Furthermore, aerosols and clouds, often present in the UTLS, complicate the measurement of trace gases. The SOCRATES sensor is a 23-channel Gas Filter Correlation Radiometer (GFCR), referred to as GLO (GFCR Limb solar Occultation), with heritage from HALOE on UARS, and SOFIE on AIM. GLO measures aerosol extinction from 0.45 to 3.88 μm, important radiatively active gases in the UTLS (H2O, O3, CH4, N2O), key tracers of UTLS transport (HCN, CO, HDO), gases important in stratospheric O3 chemistry (HCl and HF), and temperature from cloud top to 50 km at a vertical resolution of SOCRATES mission concept is a 6-element constellation of autonomous small satellites, each mated with a GLO sensor, and deployed from a single launch vehicle. The SOCRATES/GLO approach reaps the advantages of solar occultation: high precision and accuracy; robust calibration; and high vertical resolution, while mitigating the sparse coverage of a single solar occultation sensor. We present the SOCRATES science case, and key elements of the SOCRATES mission and GLO instrument concepts.

  18. Solar Occultation Constellation for Retrieving Aerosols and Trace Element Species (SOCRATES) Mission Concept

    Science.gov (United States)

    Bailey, S. M.; Bevilacqua, R. M.; Fish, C. S.; Gordley, L. L.; Fromm, M. D.

    2014-12-01

    The goal of SOCRATES is to quantify the critical role of the upper troposphere/lower stratosphere (UTLS) in the climate system. The mission would provide, for the first time, the suite of measurements required to quantify stratosphere/troposphere exchange (STE) pathways and their contribution to UTLS composition, and to evaluate the radiative forcing implications of potential changes in STE pathways with climate change. The discrimination and quantification of STE pathways requires simultaneous measurement of several key trace gases and aerosols with high precision, accuracy, and vertical resolution. Furthermore, aerosol and clouds, often present in the UTLS, complicate the measurement of trace gases. The SOCRATES sensor is a 23-channel Gas Filter Correlation Radiometer (GFCR), referred to as GLO (GFCR Limb solar Occultation), with heritage from HALOE on UARS, and SOFIE on AIM. GLO measures aerosol extinction from 0.45 to 3.88 μm, important radiatively active gases in the UTLS (H2O, O3, CH4, N2O), key tracers of STE (HCN, CO, HDO), gases important in stratospheric O3 chemistry (HCl and HF), and temperature from cloud top to 50 km at a vertical resolution of 1 km. Improved pointing knowledge will provide dramatically better retrieval precision in the UTLS, even in the presence of aerosols, than possible with HALOE. In addition, the GLO form factor is only a few percent of that of HALOE, and costs for a constellation of GLO sensors is within the cost cap of a NASA Venture mission. The SOCRATES mission concept is an 8-element constellation of autonomous CubeSats, each mated with a GLO sensor, deployed from a single launch vehicle. The SOCRATES/GLO approach reaps the advantages of solar occultation: high precision and accuracy; robust calibration; and high vertical resolution, while mitigating the sparse coverage of a single solar occultation sensor. We present the SOCRATES science case, and key elements of the SOCRATES mission and GLO instrument concepts.

  19. Imaging Seeker Surrogate for IRCM evaluation

    NARCIS (Netherlands)

    Schleijpen, H.M.A.; Carpenter, S.R.; Mellier, B.; Dimmeler, A.

    2007-01-01

    NATO-SCI-139 and its predecessor groups have more than a decade of history in the evaluation and recommendation of EO and IR Countermeasures against anti-aircraft missiles. Surrogate Seekers have proven to be a valuable tool for this work. The use of surrogate seekers in international co-operations

  20. 77 FR 34788 - Surrogate Foreign Corporations

    Science.gov (United States)

    2012-06-12

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BF47 Surrogate Foreign Corporations AGENCY: Internal... regulations regarding whether a foreign corporation is treated as a surrogate foreign corporation. The final ] regulations affect certain domestic corporations and partnerships (and certain parties related thereto),...

  1. Surrogate Guderley Test Problem Definition

    Energy Technology Data Exchange (ETDEWEB)

    Ramsey, Scott D. [Los Alamos National Laboratory; Shashkov, Mikhail J. [Los Alamos National Laboratory

    2012-07-06

    The surrogate Guderley problem (SGP) is a 'spherical shock tube' (or 'spherical driven implosion') designed to ease the notoriously subtle initialization of the true Guderley problem, while still maintaining a high degree of fidelity. In this problem (similar to the Guderley problem), an infinitely strong shock wave forms and converges in one-dimensional (1D) cylindrical or spherical symmetry through a polytropic gas with arbitrary adiabatic index {gamma}, uniform density {rho}{sub 0}, zero velocity, and negligible pre-shock pressure and specific internal energy (SIE). This shock proceeds to focus on the point or axis of symmetry at r = 0 (resulting in ostensibly infinite pressure, velocity, etc.) and reflect back out into the incoming perturbed gas.

  2. Two Species Previously Confused Under the Concept of Sabethes Tarsopus in Central America (Diptera: Culicidae)

    Science.gov (United States)

    1992-07-01

    u ., data . Ss hnqone rte s . oireorte for Information OP• etonatnd ft"ar l2t% 11¢1 fil 111111111111 1 1 Id udget P&OelwOtk Reduction 1 oje t illO 70...HONDURAS. Yoro: Camp Big ridge system (Holdridge and Budowski 1956). Bear. approx. 800 m. 7 Mar 86, R. Johnson. dominant plants consist of drought-resistant...Nijera, A. 1966. Mosquitos tropicales 1951. Descriptions of two new species of de Mexico. Rev. Invest. Salud Publica Wveom’ia and the male of

  3. Use of Surrogate end points in HTA

    Directory of Open Access Journals (Sweden)

    Mangiapane, Sandra

    2009-08-01

    Full Text Available The different actors involved in health system decision-making and regulation have to deal with the question which are valid parameters to assess the health value of health technologies.So called surrogate endpoints represent in the best case preliminary steps in the casual chain leading to the relevant outcome (e. g. mortality, morbidity and are not usually directly perceptible by patients. Surrogate endpoints are not only used in trials of pharmaceuticals but also in studies of other technologies. Their use in the assessment of the benefit of a health technology is however problematic. In this report we intend to answer the following research questions: Which criteria need to be fulfilled for a surrogate parameter to be considered a valid endpoint? Which methods have been described in the literature for the assessment of the validity of surrogate endpoints? Which methodological recommendations concerning the use of surrogate endpoints have been made by international HTA agencies? Which place has been given to surrogate endpoints in international and German HTA reports? For this purpose, we choose three different approaches. Firstly, we conduct a review of the methodological literature dealing with the issue of surrogate endpoints and their validation. Secondly, we analyse current methodological guidelines of HTA agencies members of the International network of agencies for Health Technology Assessment (INAHTA as well as of agencies concerned with assessments for reimbursement purposes. Finally, we analyse the outcome parameter used in a sample of HTA reports available for the public. The analysis of methodological guidelines shows a very cautious position of HTA institutions regarding the use of surrogate endpoints in technology assessment. Surrogate endpoints have not been prominently used in HTA reports. None of the analysed reports based its conclusions solely on the results of surrogate endpoints. The analysis of German HTA reports shows a

  4. An empirical assessment of the focal species hypothesis.

    Science.gov (United States)

    Lindenmayer, D B; Lane, P W; Westgate, M J; Crane, M; Michael, D; Okada, S; Barton, P S

    2014-12-01

    Biodiversity surrogates and indicators are commonly used in conservation management. The focal species approach (FSA) is one method for identifying biodiversity surrogates, and it is underpinned by the hypothesis that management aimed at a particular focal species will confer protection on co-occurring species. This concept has been the subject of much debate, in part because the validity of the FSA has not been subject to detailed empirical assessment of the extent to which a given focal species actually co-occurs with other species in an assemblage. To address this knowledge gap, we used large-scale, long-term data sets of temperate woodland birds to select focal species associated with threatening processes such as habitat isolation and loss of key vegetation attributes. We quantified co-occurrence patterns among focal species, species in the wider bird assemblage, and species of conservation concern. Some, but not all, focal species were associated with high levels of species richness. One of our selected focal species was negatively associated with the occurrence of other species (i.e., it was an antisurrogate)-a previously undescribed property of nominated focal species. Furthermore, combinations of focal species were not associated with substantially elevated levels of bird species richness, relative to levels associated with individual species. Our results suggest that although there is some merit to the underpinning concept of the FSA, there is also a need to ensure that actions are sufficiently flexible because management tightly focused on a given focal species may not benefit some other species, including species of conservation concern, such of which might not occur in species-rich assemblages. © 2014 Society for Conservation Biology.

  5. On Using Surrogates with Genetic Programming.

    Science.gov (United States)

    Hildebrandt, Torsten; Branke, Jürgen

    2015-01-01

    One way to accelerate evolutionary algorithms with expensive fitness evaluations is to combine them with surrogate models. Surrogate models are efficiently computable approximations of the fitness function, derived by means of statistical or machine learning techniques from samples of fully evaluated solutions. But these models usually require a numerical representation, and therefore cannot be used with the tree representation of genetic programming (GP). In this paper, we present a new way to use surrogate models with GP. Rather than using the genotype directly as input to the surrogate model, we propose using a phenotypic characterization. This phenotypic characterization can be computed efficiently and allows us to define approximate measures of equivalence and similarity. Using a stochastic, dynamic job shop scenario as an example of simulation-based GP with an expensive fitness evaluation, we show how these ideas can be used to construct surrogate models and improve the convergence speed and solution quality of GP.

  6. Regenerative healing, scar-free healing and scar formation across the species: current concepts and future perspectives.

    Science.gov (United States)

    Ud-Din, Sara; Volk, Susan W; Bayat, Ardeshir

    2014-09-01

    All species have evolved mechanisms of repair to restore tissue function following injury. Skin scarring is an inevitable and permanent endpoint for many postnatal organisms except for non-amniote vertebrates such as amphibians, which are capable of tissue regeneration. Furthermore, mammalian foetuses through mid-gestation are capable of rapid wound repair in the absence of scar formation. Notably, excessive cutaneous scar formation, such as hypertrophic and keloid scars, is a species limited clinical entity as it occurs only in humans, although wounds on the distal limbs of horses are also prone to heal with fibroproliferative pathology known as equine exuberant granulation tissue. Currently, there are no reliable treatment options to eradicate or prevent scarring in humans and vertebrates. The limited number of vertebrate models for either hypertrophic or keloid scarring has been an impediment to mechanistic studies of these diseases and the development of therapies. In this viewpoint essay, we highlight the current concepts of regenerative, scar-free and scar-forming healing compared across a number of species and speculate on areas for future research. Furthermore, in-depth investigative research into the mechanisms of scarless repair may allow for the development of improved animal models and novel targets for scar prevention. As the ability to heal in both a scarless manner and propensity for healing with excessive scar formation is highly species dependent, understanding similarities and differences in healing across species as it relates to the regenerative process may hold the key to improve scarring and guide translational wound-healing studies.

  7. Denisovans, Melanesians, Europeans, and Neandertals: The Confusion of DNA Assumptions and the Biological Species Concept.

    Science.gov (United States)

    Caldararo, Niccolo

    2016-08-01

    A number of recent articles have appeared on the Denisova fossil remains and attempts to produce DNA sequences from them. One of these recently appeared in Science by Vernot et al. (Science 352:235-239, 2016). We would like to advance an alternative interpretation of the data presented. One concerns the problem of contamination/degradation of the determined DNA sequenced. Just as the publication of the first Neandertal sequence included an interpretation that argued that Neandertals had not contributed any genes to modern humans, the Denisovan interpretation has considerable influence on ideas regarding human evolution. The new papers, however, confuse established ideas concerning the nature of species, as well as the use of terms like premodern, Archaic Homo, and Homo heidelbergensis. Examination of these problems presents a solution by means of reinterpreting the results. Given the claims for gene transfer among a number of Mid Pleistocene hominids, it may be time to reexamine the idea of anagenesis in hominid evolution.

  8. Tuberculosis cross-species transmission in Tanzania: Towards a One-Health concept

    Directory of Open Access Journals (Sweden)

    Erasto V. Mbugi

    2012-06-01

    Full Text Available For centuries, tuberculosis, which is a chronic infection caused by the bacillus Mycobacterium tuberculosis has remained a global health problem. The global burden of tuberculosis has increased, particularly in the Southern African region, mainly due to HIV, and inadequate health systems which has in turn given rise to emergent drug resistant tuberculosis (TB strains. Bovine tuberculosis (BTB has also emerged as a significant disease with the tendency for inter-species spread. The extent of interspecies BTB transmission both in urban and rural communities has not been adequately assessed. The phenomenon is of particular importance in rural communities where people share habitats with livestock and wildlife (particularly in areas near national parks and game reserves. Aerosol and oral intake are the major routes of transmission from diseased to healthy individuals, with health care workers often contracting infection nosocomially. Although TB control has increasingly been achieved in high-income countries, the disease, like other poverty-related infections, has continued to be a disaster in countries with low income economies. Transmission of infections occurs not only amongst humans but also between animals and humans (and occasionally vice versa necessitating assessment of the extent of transmission at their interface. This review explores tuberculosis as a disease of humans which can cross-transmit between humans, livestock and wildlife. The review also addresses issues underlying the use of molecular biology, genetic sequencing and bioinformatics as t tools to understand the extent of inter-species cross-transmission of TB in a ‘One Health’ context.

  9. The Confucian bioethics of surrogate decision making: its communitarian roots.

    Science.gov (United States)

    Fan, Ruiping

    2011-10-01

    The family is the exemplar community of Chinese society. This essay explores how Chinese communitarian norms, expressed in thick commitments to the authority and autonomy of the family, are central to contemporary Chinese bioethics. In particular, it focuses on the issue of surrogate decision making to illustrate the Confucian family-grounded communitarian bioethics. The essay first describes the way in which the family, in Chinese bioethics, functions as a whole to provide consent for significant medical and surgical interventions when a patient has lost decision-making capacity. It is argued that the practice of not having an established order for surrogate decision makers (e.g., spouse, children, and then parents), as it is done in the United States, reflects the acknowledgment that the family as a social reality cannot be reduced to a stereotype of the appropriate order of default decision makers. This description of the family as being in authority to make surrogate decisions for an incompetent family member is enriched by an elaboration of the differences among the concepts of patient autonomy, family autonomy, and moral autonomy. The Chinese model, as well as the Confucian communitarian life of families, engages a family autonomy that is supported by a Confucian understanding of moral autonomy, rather than individual autonomy. Finally, the issue of possible conflicts between patient and family interests in relation to a patient's past wishes in the Chinese model is addressed in light of the role of the physician.

  10. Thin-layer voltammetry of soluble species on screen-printed electrodes: proof of concept.

    Science.gov (United States)

    Botasini, S; Martí, A C; Méndez, E

    2016-10-17

    Thin-layer diffusion conditions were accomplished on screen-printed electrodes by placing a controlled-weight onto the cast solution and allowing for its natural spreading. The restricted diffusive conditions were assessed by cyclic voltammetry at low voltage scan rates and electrochemical impedance spectroscopy. The relationship between the weight exerted over the drop and the thin-layer thickness achieved was determined, in such a way that the simple experimental set-up designed for this work could be developed into a commercial device with variable control of the thin-layer conditions. The experimental results obtained resemble those reported for the voltammetric features of electroactive soluble species employing electrodes modified with carbon nanotubes or graphene layers, suggesting that the attainment of the benefits reported for these nanomaterials could be done simply by forcing the solution to spread over the screen-printed electrodic system to form a thin layer solution. The advantages of thin-layer voltammetry in the kinetic characterization of quasi-reversible and irreversible processes are highlighted.

  11. Taxonomic identification of algae (morphological and molecular): species concepts, methodologies, and their implications for ecological bioassessment.

    Science.gov (United States)

    Manoylov, Kalina M

    2014-06-01

    Algal taxonomy is a key discipline in phycology and is critical for algal genetics, physiology, ecology, applied phycology, and particularly bioassessment. Taxonomic identification is the most common analysis and hypothesis-testing endeavor in science. Errors of identification are often related to the inherent problem of small organisms with morphologies that are difficult to distinguish without research-grade microscopes and taxonomic expertise in phycology. Proposed molecular approaches for taxonomic identification from environmental samples promise rapid, potentially inexpensive, and more thorough culture-independent identification of all algal species present in a sample of interest. Molecular identification has been used in biodiversity and conservation, but it also has great potential for applications in bioassessment. Comparisons of morphological and molecular identification of benthic algal communities are improved by the identification of more taxa; however, automated identification technology does not allow for the simultaneous analysis of thousands of samples. Currently, morphological identification is used to verify molecular taxonomic identities, but with the increased number of taxa verified in algal gene libraries, molecular identification will become a universal tool in biological studies. Thus, in this report, successful application of molecular techniques related to algal bioassessment is discussed.

  12. Parents and children: "surrogate" paradigm of modernity.

    Science.gov (United States)

    Adam, Archimandrite; Akhaladze, Vakhtang

    2011-06-01

    The article provides an overview of surrogate motherhood--one of many currently available forms of Assisted Reproductive Technologies for couples who find themselves unable to conceive a child on their own. Within the years of its existence surrogate motherhood managed to accumulate lots of bioethical problems, paradoxes, dilemmas and collisions. Author represents some of them. Also the legal, moral and religious implications of surrogacy are addressed. The religious perspective from the Orthodox Christian, Catholic, Jewish, Hinduism, and Islamic points of view are provided. The author concludes that surrogate motherhood is not only the answer to childlessness but it supports metamorphosis of traditional attitude towards such human value as it is a family.

  13. Correlative and dynamic species distribution modelling for ecological predictions in the Antarctic: a cross-disciplinary concept

    Directory of Open Access Journals (Sweden)

    Thomas Saucède

    2012-05-01

    Full Text Available Developments of future scenarios of Antarctic ecosystems are still in their infancy, whilst predictions of the physical environment are recognized as being of global relevance and corresponding models are under continuous development. However, in the context of environmental change simulations of the future of the Antarctic biosphere are increasingly demanded by decision makers and the public, and are of fundamental scientific interest. This paper briefly reviews existing predictive models applied to Antarctic ecosystems before providing a conceptual framework for the further development of spatially and temporally explicit ecosystem models. The concept suggests how to improve approaches to relating species’ habitat description to the physical environment, for which a case study on sea urchins is presented. In addition, the concept integrates existing and new ideas to consider dynamic components, particularly information on the natural history of key species, from physiological experiments and biomolecular analyses. Thereby, we identify and critically discuss gaps in knowledge and methodological limitations. These refer to process understanding of biological complexity, the need for high spatial resolution oceanographic data from the entire water column, and the use of data from biomolecular analyses in support of such ecological approaches. Our goal is to motivate the research community to contribute data and knowledge to a holistic, Antarctic-specific, macroecological framework. Such a framework will facilitate the integration of theoretical and empirical work in Antarctica, improving our mechanistic understanding of this globally influential ecoregion, and supporting actions to secure this biodiversity hotspot and its ecosystem services.

  14. Biopolicies and biotechnologies: reflections on surrogate maternity in India

    Directory of Open Access Journals (Sweden)

    Mónica Amador

    2010-07-01

    Full Text Available This article explores the impact of biotechnology, particularly on assisted reproductive technologies such as surrogate motherhood. The study is based on interviews and field work conducted in the city of Hyderabad in India within the frame of the seminar on “Research Methodology” given by Dr. Rohan D´Souza at the Centre for Studies in Science Policy at the Jawaharlal Nehru University in India. The theoretical framework of this analysis focuses on exploring concepts such as cyborg (Haraway,1991 and subaltern subject (Spivak, 1998 in the context of biotechnological production in India

  15. Surrogate endpoints and emerging surrogate endpoints for risk reduction of cardiovascular disease.

    Science.gov (United States)

    Rasnake, Crystal M; Trumbo, Paula R; Heinonen, Therese M

    2008-02-01

    This article reviews surrogate endpoints and emerging biomarkers that were discussed at the annual "Cardiovascular Biomarkers and Surrogate Endpoints" symposium cosponsored by the US Food and Drug Administration (FDA) and the Montreal Heart Institute. The FDA's Center for Food Safety and Applied Nutrition (CFSAN) uses surrogate endpoints in its scientific review of a substance/disease relationship for a health claim. CFSAN currently recognizes three validated surrogate endpoints: blood pressure, blood total cholesterol, and blood low-density lipoprotein (LDL) concentration in its review of a health claim for cardiovascular disease (CVD). Numerous potential surrogate endpoints of CVD are being evaluated as the pathophysiology of heart disease is becoming better understood. However, these emerging biomarkers need to be validated as surrogate endpoints before they are used by CFSAN in the evaluation of a CVD health claim.

  16. Surrogate mothers: whose baby is it?

    Science.gov (United States)

    Cohen, B

    1984-01-01

    Advances in medical technology offer infertile couples who wish to raise children alternatives to adoption. The increasing number of surrogate mother contracts creates a myriad of legal issues surrounding the rights of the natural mother, the natural father and the child that is produced. In this Article, the Author discusses the legal issues and rights of the parties under the Constitution, the surrogate contract and family law principles. The Author proposes that courts should consider a surrogate contract as a revocable prebirth agreement which allows the natural mother to keep the child if she chooses. In addition, the Author advocates an interpretation of the statutes forbidding baby selling that would prohibit surrogate contracts in which the mother is paid a fee for the child.

  17. Neutron capture cross sections from Surrogate measurements

    Directory of Open Access Journals (Sweden)

    Scielzo N.D.

    2010-03-01

    Full Text Available The prospects for determining cross sections for compound-nuclear neutron-capture reactions from Surrogate measurements are investigated. Calculations as well as experimental results are presented that test the Weisskopf-Ewing approximation, which is employed in most analyses of Surrogate data. It is concluded that, in general, one has to go beyond this approximation in order to obtain (n,γ cross sections of sufficient accuracy for most astrophysical and nuclear-energy applications.

  18. Premixed flame chemistry of a gasoline primary reference fuel surrogate

    KAUST Repository

    Selim, Hatem

    2017-03-10

    Investigating the combustion chemistry of gasoline surrogate fuels promises to improve detailed reaction mechanisms used for simulating their combustion. In this work, the combustion chemistry of one of the simplest, but most frequently used gasoline surrogates – primary reference fuel 84 (PRF 84, 84 vol% iso-octane and 16 vol% n-heptane), has been examined in a stoichiometric premixed laminar flame. Time-of-flight mass spectrometry coupled with a vacuum ultraviolet (VUV) synchrotron light source for species photoionization was used. Reactants, major end-products, stable intermediates, free radicals, and isomeric species were detected and quantified. Numerical simulations were conducted using a detailed chemical kinetic model with the most recently available high temperature sub-mechanisms for iso-octane and heptane, built on the top of an updated pentane isomers model and AramcoMech 2.0 (C0C4) base chemistry. A detailed interpretation of the major differences between the mechanistic pathways of both fuel components is given. A comparison between the experimental and numerical results is depicted and rate of production and sensitivity analyses are shown for the species with considerable disagreement between the experimental and numerical findings.

  19. Surrogates for herbicide removal in stormwater biofilters.

    Science.gov (United States)

    Zhang, Kefeng; Deletic, Ana; Page, Declan; McCarthy, David T

    2015-09-15

    Real time monitoring of suitable surrogate parameters are critical to the validation of any water treatment processes, and is of particularly high importance for validation of natural stormwater treatment systems. In this study, potential surrogates for herbicide removal in stormwater biofilters (also known as stormwater bio-retention or rain-gardens) were assessed using field challenge tests and matched laboratory column experiments. Differential UV absorbance at 254mn (ΔUVA254), total phosphorus (ΔTP), dissolved phosphorus (ΔDP), total nitrogen (ΔTN), ammonia (ΔNH3), nitrate and nitrite (ΔNO3+NO2), dissolved organic carbon (ΔDOC) and total suspended solids (ΔTSS) were compared with glyphosate, atrazine, simazine and prometryn removal rates. The influence of different challenge conditions on the performance of each surrogate was studied. Differential TP was significantly and linearly related to glyphosate reduction (R(2) = 0.75-0.98, P herbicides were reliable under normal and challenge dry conditions, but weaker correlations were observed under challenge wet conditions. Of those tested, ΔTP is the most promising surrogate for glyphosate removal and ΔUVA254 is a suitable surrogate for triazines removal in stormwater biofilters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Developmental biotechnology for aquaculture, with special reference to surrogate production in teleost fishes

    Science.gov (United States)

    Yamaha, Etsuro; Saito, Taiju; Goto-Kazeto, Rie; Arai, Katsutoshi

    2007-07-01

    This review introduces surrogate production as a new technique for fish-seed production in aquaculture. Surrogate production in fish is a technique used to obtain the gametes of a certain genotype through the gonad of another genotype. It is achieved by inducing germ-line chimerism between different species during early development. Primordial germ cells (PGCs) are the key material of this technique to induce germ-line chimera. In several species, it has been reported that PGCs differentiated from the blastomeres inherited some maternally supplied mRNA located in the terminal regions of the early cleavage furrows. PGCs from donor species (or strains) are isolated and transplanted into host species to induce the germ-line chimera. Four methods for inducing germ-line chimera are described: blastomere transplantation, blastoderm-graft transplantation, transplantation of PGC from the genital ridge, and transplantation visualised PGC with GFP fluorescence. Several problems preventing the successful induction of germ-line chimera in various fish species are discussed. Surrogate production, however, opens the possibility of efficient fish-seed production and effective breeding and transfer of biodiversity to an aquaculture strain. Conservation and efficient utilisation of genetic resources will be achieved through surrogate production combined with the cryopreservation of PGCs.

  1. Coastal aquifer management under parameter uncertainty: Ensemble surrogate modeling based simulation-optimization

    Science.gov (United States)

    Janardhanan, S.; Datta, B.

    2011-12-01

    saltwater intrusion are considered. The salinity levels resulting at strategic locations due to these pumping are predicted using the ensemble surrogates and are constrained to be within pre-specified levels. Different realizations of the concentration values are obtained from the ensemble predictions corresponding to each candidate solution of pumping. Reliability concept is incorporated as the percent of the total number of surrogate models which satisfy the imposed constraints. The methodology was applied to a realistic coastal aquifer system in Burdekin delta area in Australia. It was found that all optimal solutions corresponding to a reliability level of 0.99 satisfy all the constraints and as reducing reliability level decreases the constraint violation increases. Thus ensemble surrogate model based simulation-optimization was found to be useful in deriving multi-objective optimal pumping strategies for coastal aquifers under parameter uncertainty.

  2. Biomedically assisted reproduction and child birth: Surrogate motherhood in comparative European law and Serbia

    Directory of Open Access Journals (Sweden)

    Kovaček-Stanić Gordana

    2013-01-01

    Full Text Available Surrogate motherhood is an arrangement in which a woman agrees to carry and deliver a child for another couple who ordered the pregnancy. This procedure is applied today in Great Britain, Holland (although without legal regulations, Israel, Greece, Ukraine, Armenia, Georgia, the USA and Australia, and it is forbidden in France, Austria, Spain, Germany, Switzerland and Slovenia. There are two types of surrogacy, one when the woman gives birth to a child who is genetically her own ("partial", genetic surrogacy, and the other where the surrogate mother only carries and gives birth to a child, whereby the child is genetically from the couple that wanted the child, or the fertilized egg is from a third woman (donor, or the embryo was donated ("full", "total", gestational surrogacy. In these cases two women take part in conception and birth of the child while in the last case there is a third woman who will raise the child. Biologically observed, the woman whose egg has been fertilized may be called the genetic mother, while the woman who carried the pregnancy and gave birth to the child - the gestational carrier. Taking into consideration that the Preliminary Draft of the Serbian Civil Law anticipates the introduction of surrogate motherhood into domestic law, we believe restrictive solutions should first be taken into consideration. This would mean that only full surrogating should be allowed, namely the egg should be from the woman who wants the child and not the surrogate mother. In domestic conditions, genetic surrogation should not be allowed as it leads to confusion in family relations, and kinships still have an important social and legal significance in our country. The surrogate mother should be a woman who has already given birth, because in that way any possible shocks which might arise after birth when the woman who has to handover the child to the intended couple would be avoided. The next condition would be that persons involved in this

  3. Nitrate Salt Surrogate Blending Scoping Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Anast, Kurt Roy [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-13

    Test blending equipment identified in the “Engineering Options Assessment Report: Nitrate Salt Waste Stream Processing”. Determine if the equipment will provide adequate mixing of zeolite and surrogate salt/Swheat stream; optimize equipment type and operational sequencing; impact of baffles and inserts on mixing performance; and means of validating mixing performance

  4. Videotrees: Improving video surrogate presentation using hierarchy

    NARCIS (Netherlands)

    Jansen, Michel; Heeren, Willemijn; Dijk, van Betsy

    2008-01-01

    As the amount of available video content increases, so does the need for better ways of browsing all this material. Because the nature of video makes it hard to process, the need arises for adequate surrogates for video that can readily be skimmed and browsed. In this paper, the effects of the use o

  5. A novel surrogate index for hepatic insulin resistance.

    LENUS (Irish Health Repository)

    Vangipurapu, J

    2011-03-01

    In epidemiological and genetic studies surrogate indices are needed to investigate insulin resistance in different insulin-sensitive tissues. Our objective was to develop a surrogate index for hepatic insulin resistance.

  6. Surrogate fuel formulation for light naphtha combustion in advanced combustion engines

    KAUST Repository

    Ahmed, Ahfaz

    2015-03-30

    Crude oil once recovered is further separated in to several distinct fractions to produce a range of energy and chemical products. One of the less processed fractions is light naphtha (LN), hence they are more economical to produce than their gasoline and diesel counterparts. Recent efforts have demonstrated usage of LN as transportation fuel for internal combustion engines with slight modifications. In this study, a multicomponent surrogate fuel has been developed for light naphtha fuel using a multi-variable nonlinear constrained optimization scheme. The surrogate, consisting of palette species n-pentane, 2-methylhexane, 2-methylbutane, n-heptane and toluene, was validated against the LN using ignition quality tester following ASTM D6890 methodology. Comparison of LN and the surrogate fuel demonstrated satisfactory agreement.

  7. Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

    Science.gov (United States)

    Yang, Feiling; Hu, Jinming; Wu, Ruidong

    2016-08-01

    Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan’s protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

  8. Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China.

    Science.gov (United States)

    Yang, Feiling; Hu, Jinming; Wu, Ruidong

    2016-08-19

    Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that endangered plants had higher surrogacy values than endangered animals but that the two were not substitutable; coupled endangered plants and animals as surrogates yielded a higher surrogacy value than endangered plants or animals as surrogates; the plant-animal priority areas (PAPAs) was the optimal among the four types of PCAs for conserving both endangered plants and animals in Yunnan. PAPAs could well represent overall species diversity distribution patterns and overlap with critical biogeographical regions in Yunnan. Fourteen priority units in PAPAs should be urgently considered as optimizing Yunnan's protected area system. The spatial pattern of PAPAs at the 100% conservation level could be conceptualized into three connected conservation belts, providing a valuable reference for optimizing the layout of the in situ protected area system in Yunnan.

  9. A qualitative investigation of selecting surrogate decision-makers

    NARCIS (Netherlands)

    Edwards, S.J.L.; Brown, P.; Twyman, M.A.; Christie, D.; Rakow, T.

    2011-01-01

    Background Empirical studies of surrogate decision-making tend to assume that surrogates should make only a 'substituted judgement'—that is, judge what the patient would want if they were mentally competent. Objectives To explore what people want in a surrogate decision-maker whom they themselves se

  10. System Reliability Analysis Capability and Surrogate Model Application in RAVEN

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian; Alfonsi, Andrea; Huang, Dongli; Gleicher, Frederick; Wang, Bei; Adbel-Khalik, Hany S.; Pascucci, Valerio; Smith, Curtis L.

    2015-11-01

    This report collect the effort performed to improve the reliability analysis capabilities of the RAVEN code and explore new opportunity in the usage of surrogate model by extending the current RAVEN capabilities to multi physics surrogate models and construction of surrogate models for high dimensionality fields.

  11. Surrogate decision making and intellectual virtue.

    Science.gov (United States)

    Bock, Gregory L

    2014-01-01

    Patients can be harmed by a religiously motivated surrogate decision maker whose decisions are contrary to the standard of care; therefore, surrogate decision making should be held to a high standard. Stewart Eskew and Christopher Meyers proposed a two-part rule for deciding which religiously based decisions to honor: (1) a secular reason condition and (2) a rationality condition. The second condition is based on a coherence theory of rationality, which they claim is accessible, generous, and culturally sensitive. In this article, I will propose strengthening the rationality condition by grounding it in a theory of intellectual virtue, which is both rigorous and culturally sensitive. Copyright 2014 The Journal of Clinical Ethics. All rights reserved.

  12. The Surrogate Method: Past, Present and Future

    Energy Technology Data Exchange (ETDEWEB)

    Lesher, S R; Bernstein, L A; Burke, J T; Lyles, B F; Clark, R M; Fallon, P; Phair, L

    2008-01-09

    The STARS/LiBerACE collaboration has been exploring the surrogate technique with success in the actinide region. This method uses a direct reaction to measure the decay probability of the same compound nucleus produced via a neutron-induced channel. This paper serves as an overview of these activities. Using the STARS array at 88-inch Cyclotron at Lawrence Berkeley National Laboratory we have explored the following surrogate reactions: {sup 234}U({alpha}, {alpha}{prime}f), {sup 235}U({sup 3}He, {alpha}f), {sup 236}U({alpha}, {alpha}{prime}f), {sup 238}U ({alpha},{alpha}{prime}f), {sup 238}U({sup 3}He,{alpha}f), {sup 238}U({sup 3}He, tf) surrogates for {sup 233}U(n,f), {sup 233}U(n,f), {sup 235}U(n,f), {sup 237}U(n,f), {sup 236}U(n,f), and {sup 237}Np(n,f), respectively.

  13. [Biomedical Perspective of the Surrogate Motherhood].

    Science.gov (United States)

    Jouve de la Barreda, Nicolás

    2017-01-01

    The subrogated motherhood takes place when an embryo created by in vitro fertilization (IVF) technology is implanted in a surrogate, sometimes called a gestational mother, by means a contract with her. It can imply to natural families (woman and man) with or without infertility problems, or to monoparental or biparental families of the same sex. Concerning the origin of the gametes used in the IVF emerges different implications on the genetic relationship of the resulting child with the surrogate and the future parents. The subrogated motherhood was initially considered an option to solve infertility problems. Nevertheless this practice has become a possible and attractive option as a source of economic resources for poor women. The cases of benefit of a pregnancy without mediating a contract are exceptional and they are not properly cases of ″subrogated maternity″ but of ″altruistic maternity″ and must be considered as heterologous in vitro fertilization. In this article are analyzed the medical, genetic and bioethics aspects of this new derivation of the fertilization in vitro. As points of special attention are considered the following questions: Is it the surrogate motherhood used preferably to solve infertility problems? Is not this actually a new form of exploitation of the woman? Does not suppose an attack to the natural family? Does not suppose in addition an attack to the dignity of the human being?

  14. Improving Mixed Variable Optimization of Computational and Model Parameters Using Multiple Surrogate Functions

    Science.gov (United States)

    2008-03-01

    Mathematics and Theoretical Physics, Cambridge University, August 1992. 23. Booker, A. J., J. E. Dennis, Jr, P. D. Frank, D. B. Serafini , V. Torczon, and M...J., J. E. Dennis, Jr., P. D. Frank, D. W. Moore, and D. B. Serafini . Managing Surrogate Objectives to Optimize a Helicopter Rotor Design - Further...L. A., Jr., and H. Miura. “Approximation Concepts for Efficient Struc- tural Synthesis”. Technical Report CR-2552, NASA, 1976. 78. Serafini , D. B. A

  15. Surrogate formulations for thermal treatment of low-level mixed waste. Part 1: Radiological surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Stockdale, J.A.D.; Bostick, W.D.; Hoffmann, D.P. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States); Lee, H.T. [Oak Ridge Associated Universities, TN (United States)

    1994-01-01

    The evaluation and comparison of proposed thermal treatment systems for mixed wastes can be expedited by tests in which the radioactive components of the wastes are replaced by surrogate materials chosen to mimic, as far as is possible, the chemical and physical properties of the radioactive materials of concern. In this work, sponsored by the Mixed Waste Integrated Project of the US Department of Energy, the authors have examined reported experience with such surrogates and suggest a simplified standard list of materials for use in tests of thermal treatment systems. The chief radioactive nuclides of concern in the treatment of mixed wastes are {sup 239}Pu, {sup 238}U, {sup 235}U, {sup 137}Cs, {sup 103}Ru, {sup 99}Tc, and {sup 90}Sr. These nuclides are largely by-products of uranium enrichment, reactor fuel reprocessing, and weapons program activities. Cs, Ru, and Sr all have stable isotopes that can be used as perfect surrogates for the radioactive forms. Technetium exists only in radioactive form, as do plutonium and uranium. If one wishes to preclude radioactive contamination of the thermal treatment system under trial burn, surrogate elements must be chosen for these three. For technetium, the authors suggest the use of natural ruthenium, and for both plutonium and uranium, they recommend cerium. The seven radionuclides listed can therefore be simulated by a surrogate package containing stable isotopes of ruthenium, strontium, cesium, and cerium.

  16. Testing Pairwise Association between Spatially Autocorrelated Variables: A New Approach Using Surrogate Lattice Data

    Science.gov (United States)

    Deblauwe, Vincent; Kennel, Pol; Couteron, Pierre

    2012-01-01

    validation of species distribution models. An implementation of the method in Java for the generation of wavelet-based surrogates is available online as supporting material. PMID:23144961

  17. Testing pairwise association between spatially autocorrelated variables: a new approach using surrogate lattice data.

    Directory of Open Access Journals (Sweden)

    Vincent Deblauwe

    potential for validation of species distribution models. An implementation of the method in Java for the generation of wavelet-based surrogates is available online as supporting material.

  18. Process-based modeling of species' responses to climate change - a proof of concept using western North American trees

    Science.gov (United States)

    Evans, M. E.; Merow, C.; Record, S.; Menlove, J.; Gray, A.; Cundiff, J.; McMahon, S.; Enquist, B. J.

    2013-12-01

    Current attempts to forecast how species' distributions will change in response to climate change suffer under a fundamental trade-off: between modeling many species superficially vs. few species in detail (between correlative vs. mechanistic models). The goals of this talk are two-fold: first, we present a Bayesian multilevel modeling framework, dynamic range modeling (DRM), for building process-based forecasts of many species' distributions at a time, designed to address the trade-off between detail and number of distribution forecasts. In contrast to 'species distribution modeling' or 'niche modeling', which uses only species' occurrence data and environmental data, DRMs draw upon demographic data, abundance data, trait data, occurrence data, and GIS layers of climate in a single framework to account for two processes known to influence range dynamics - demography and dispersal. The vision is to use extensive databases on plant demography, distributions, and traits - in the Botanical Information and Ecology Network, the Forest Inventory and Analysis database (FIA), and the International Tree Ring Data Bank - to develop DRMs for North American trees. Second, we present preliminary results from building the core submodel of a DRM - an integral projection model (IPM) - for a sample of dominant tree species in western North America. IPMs are used to infer demographic niches - i.e., the set of environmental conditions under which population growth rate is positive - and project population dynamics through time. Based on >550,000 data points derived from FIA for nine tree species in western North America, we show IPM-based models of their current and future distributions, and discuss how IPMs can be used to forecast future forest productivity, mortality patterns, and inform efforts at assisted migration.

  19. Surrogate-assisted feature extraction for high-throughput phenotyping.

    Science.gov (United States)

    Yu, Sheng; Chakrabortty, Abhishek; Liao, Katherine P; Cai, Tianrun; Ananthakrishnan, Ashwin N; Gainer, Vivian S; Churchill, Susanne E; Szolovits, Peter; Murphy, Shawn N; Kohane, Isaac S; Cai, Tianxi

    2017-04-01

    Phenotyping algorithms are capable of accurately identifying patients with specific phenotypes from within electronic medical records systems. However, developing phenotyping algorithms in a scalable way remains a challenge due to the extensive human resources required. This paper introduces a high-throughput unsupervised feature selection method, which improves the robustness and scalability of electronic medical record phenotyping without compromising its accuracy. The proposed Surrogate-Assisted Feature Extraction (SAFE) method selects candidate features from a pool of comprehensive medical concepts found in publicly available knowledge sources. The target phenotype's International Classification of Diseases, Ninth Revision and natural language processing counts, acting as noisy surrogates to the gold-standard labels, are used to create silver-standard labels. Candidate features highly predictive of the silver-standard labels are selected as the final features. Algorithms were trained to identify patients with coronary artery disease, rheumatoid arthritis, Crohn's disease, and ulcerative colitis using various numbers of labels to compare the performance of features selected by SAFE, a previously published automated feature extraction for phenotyping procedure, and domain experts. The out-of-sample area under the receiver operating characteristic curve and F -score from SAFE algorithms were remarkably higher than those from the other two, especially at small label sizes. SAFE advances high-throughput phenotyping methods by automatically selecting a succinct set of informative features for algorithm training, which in turn reduces overfitting and the needed number of gold-standard labels. SAFE also potentially identifies important features missed by automated feature extraction for phenotyping or experts.

  20. Boron as a surrogate for N-nitrosodimethylamine rejection by reverse osmosis membranes in potable water reuse applications.

    Science.gov (United States)

    Tu, Kha L; Fujioka, Takahiro; Khan, Stuart J; Poussade, Yvan; Roux, Annalie; Drewes, Jörg E; Chivas, Allan R; Nghiem, Long D

    2013-06-18

    The results of this study reveal a strong linear correlation (R(2) = 0.95) between the rejections of boron and N-nitrosodimethylamine (NDMA) by six different reverse osmosis (RO) membranes, suggesting that boron can be used as a surrogate for NDMA rejection. This proposal is based on the premise that the rejection of both boric acid and NDMA is governed by steric hindrance and that they have similar molecular dimensions. The concept proposed here is shown to be valid at pH 8 or below where boron exists as the neutral boric acid species and NDMA is also a neutral solute. Observed changes in the rejections of these two species, as a function of permeate fluxes and feed solution temperatures, were also almost identical. Boron rejection increased from 21 to 79%, and the correlation coefficient of the linear regression between boron and NDMA rejections was 0.99 as the permeate flux increased from 5 to 60 L m(-2)h(-1). Similarly, a linear correlation between boron and NDMA rejections was observed as the feed solution temperature increased from 10 to 40 °C. This linear correlation was also validated in a tertiary treated effluent matrix.

  1. Recent Experimental Progress on Surrogate Reactions

    Science.gov (United States)

    Beausang, Cornelius

    2014-09-01

    Reactions on unstable nuclei are important in a wide variety of nuclear physics scenarios. Cross sections for neutron (or light charged particle) induced reactions on target nuclei spanning the chart of the nuclei are important for nuclear astrophysics (r-process, s-process rp- and p-processes etc.), for nuclear energy generation and for national security applications. Many such reactions occur on short-lived unstable nuclei. Even with the present generation of radioactive beam facilities, many such reactions are difficult, if not impossible, to measure directly. For these reactions, often the surrogate reaction technique provides the only option to provide some experimental guidance for the calculations. The experimental and theoretical techniques required are described in some detail in the recent review article by Escher et al.. Originally introduced in the 1970's the last decade has seen a resurgence of interest in the surrogate technique. Various ratio techniques, external, internal and hybrid, have been developed to minimize the effect of target contamination. In the actinide region, a large number of surrogate (n,f) cross sections have been measured. In general, these show agreement to within 5--10%, with directly measured (n,f) data where these data exist (benchmarking), for equivalent neutron energies ranging from ~100 keV up to tens of MeV. For (n, γ) reactions, measurements have been attempted for select nuclei in various mass regions (A ~ 90, 150 and 235) and for these the agreement with directly measured data is less good. The various experimental techniques employed will be described as well as the current state of the experimental data. Some future directions will be described. Reactions on unstable nuclei are important in a wide variety of nuclear physics scenarios. Cross sections for neutron (or light charged particle) induced reactions on target nuclei spanning the chart of the nuclei are important for nuclear astrophysics (r-process, s

  2. Using comparative genomic hybridization to survey genomic sequence divergence across species: a proof-of-concept from Drosophila

    Directory of Open Access Journals (Sweden)

    Kulathinal Rob J

    2010-04-01

    Full Text Available Abstract Background Genome-wide analysis of sequence divergence among species offers profound insights into the evolutionary processes that shape lineages. When full-genome sequencing is not feasible for a broad comparative study, we propose the use of array-based comparative genomic hybridization (aCGH in order to identify orthologous genes with high sequence divergence. Here we discuss experimental design, statistical power, success rate, sources of variation and potential confounding factors. We used a spotted PCR product microarray platform from Drosophila melanogaster to assess sequence divergence on a gene-by-gene basis in three fully sequenced heterologous species (D. sechellia, D. simulans, and D. yakuba. Because complete genome assemblies are available for these species this study presents a powerful test for the use of aCGH as a tool to measure sequence divergence. Results We found a consistent and linear relationship between hybridization ratio and sequence divergence of the sample to the platform species. At higher levels of sequence divergence (D. melanogaster ~84% of features had significantly less hybridization to the array in the heterologous species than the platform species, and thus could be identified as "diverged". At lower levels of divergence (≥ 97% identity, only 13% of genes were identified as diverged. While ~40% of the variation in hybridization ratio can be accounted for by variation in sequence identity of the heterologous sample relative to D. melanogaster, other individual characteristics of the DNA sequences, such as GC content, also contribute to variation in hybridization ratio, as does technical variation. Conclusions Here we demonstrate that aCGH can accurately be used as a proxy to estimate genome-wide divergence, thus providing an efficient way to evaluate how evolutionary processes and genomic architecture can shape species diversity in non-model systems. Given the increased number of species for which

  3. Concept - or no concept

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1999-01-01

    Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown......Discussion about concept in industrial companies. A method for mapping of managerial concept in specific area is shown...

  4. Surrogate Markers of Abdominal Aortic Aneurysm Progression.

    Science.gov (United States)

    Wanhainen, Anders; Mani, Kevin; Golledge, Jonathan

    2016-02-01

    The natural course of many abdominal aortic aneurysms (AAA) is to gradually expand and eventually rupture and monitoring the disease progression is essential to their management. In this publication, we review surrogate markers of AAA progression. AAA diameter remains the most widely used and important marker of AAA growth. Standardized reporting of reproducible methods of measuring AAA diameter is essential. Newer imaging assessments, such as volume measurements, biomechanical analyses, and functional and molecular imaging, as well as circulating biomarkers, have potential to add important information about AAA progression. Currently, however, there is insufficient evidence to recommend their routine use in clinical practice.

  5. Effectiveness of amphibians as biodiversity surrogates in pond conservation.

    Science.gov (United States)

    Ilg, Christiane; Oertli, Beat

    2017-04-01

    Amphibian decline has led to worldwide conservation efforts, including the identification and designation of sites for their protection. These sites could also play an important role in the conservation of other freshwater taxa. In 89 ponds in Switzerland, we assessed the effectiveness of amphibians as a surrogate for 4 taxonomic groups that occur in the same freshwater ecosystems as amphibians: dragonflies, aquatic beetles, aquatic gastropods, and aquatic plants. The ponds were all of high value for amphibian conservation. Cross-taxon correlations were tested for species richness and conservation value, and Mantel tests were used to investigate community congruence. Species richness, conservation value, and community composition of amphibians were weakly congruent with these measures for the other taxonomic groups. Paired comparisons for the 5 groups considered showed that for each metric, amphibians had the lowest degree of congruence. Our results imply that site designation for amphibian conservation will not necessarily provide protection for freshwater biodiversity as a whole. To provide adequate protection for freshwater species, we recommend other taxonomic groups be considered in addition to amphibians in the prioritization and site designation process. © 2016 Society for Conservation Biology.

  6. Habitats as surrogates of taxonomic and functional fish assemblages in coral reef ecosystems: a critical analysis of factors driving effectiveness.

    Directory of Open Access Journals (Sweden)

    Simon Van Wynsberge

    Full Text Available Species check-lists are helpful to establish Marine Protected Areas (MPAs and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate's distribution, quantity and location of fish census stations (target surrogate's sampling, and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator

  7. Bacillus thuringiensis as a surrogate for Bacillus anthracis in aerosol research.

    Science.gov (United States)

    Tufts, Jenia A M; Calfee, M Worth; Lee, Sang Don; Ryan, Shawn P

    2014-05-01

    Characterization of candidate surrogate spores prior to experimental use is critical to confirm that the surrogate characteristics are as closely similar as possible to those of the pathogenic agent of interest. This review compares the physical properties inherent to spores of Bacillus anthracis (Ba) and Bacillus thuringiensis (Bt) that impact their movement in air and interaction with surfaces, including size, shape, density, surface morphology, structure and hydrophobicity. Also evaluated is the impact of irradiation on the physical properties of both Bacillus species. Many physical features of Bt and Ba have been found to be similar and, while Bt is considered typically non-pathogenic, it is in the B. cereus group, as is Ba. When cultured and sporulated under similar conditions, both microorganisms share a similar cylindrical pellet shape, an aerodynamic diameter of approximately 1 μm (in the respirable size range), have an exosporium with a hairy nap, and have higher relative hydrophobicities than other Bacillus species. While spore size, morphology, and other physical properties can vary among strains of the same species, the variations can be due to growth/sporulation conditions and may, therefore, be controlled. Growth and sporulation conditions are likely among the most important factors that influence the representativeness of one species, or preparation, to another. All Bt spores may, therefore, not be representative of all Ba spores. Irradiated spores do not appear to be a good surrogate to predict the behavior of non-irradiated spores due to structural damage caused by the irradiation. While the use of Bt as a surrogate for Ba in aerosol testing appears to be well supported, this review does not attempt to narrow selection between Bt strains. Comparative studies should be performed to test the hypothesis that viable Ba and Bt spores will behave similarly when suspended in the air (as an aerosol) and to compare the known microscale characteristics

  8. Surrogate-based modeling and dimension reduction techniques for multi-scale mechanics problems

    Institute of Scientific and Technical Information of China (English)

    Wei Shyy; Young-Chang Cho; Wenbo Du; Amit Gupta; Chien-Chou Tseng; Ann Marie Sastry

    2011-01-01

    Successful modeling and/or design of engineering systems often requires one to address the impact of multiple “design variables” on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware's overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium (Li)-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for “scale bridging.”

  9. Surrogating Bodies, Embodiment of Theories (Vekalet Eden Bedenler, Cisimleşen Kuramlar

    Directory of Open Access Journals (Sweden)

    Kubilay AKMAN

    2011-01-01

    Full Text Available Hollywood has intrigued critical minds through controversial films, especially in science-fiction, which might be considered as crossroads of several sociological, philosophical and cultural concepts/issues. The Surrogates (Jonathan Mostow, 2009 is one of the latest representatives in this "genre". When people of the future (let us call them Techno Sapiens use their remotely-controlled "bodies", which are just perfectly designed robots, in order to avoid having any damage in their real "bodies", meaning of body, social relations, pleasure, life, experience, risk, Etc. shift into a very complicated level that provides a wide range of opportunities to discuss contemporary sociological and theoretical lines including body and politics, power, bio-politics, gender, everyday life and so on. This paper has the intention of discussing all these theoretical issues through reading Giorgio Agamben, Michel Foucault, Gilles Deleuze, Jean Baudrillard and Slavoj Zizek. Cinema is a symptomatic field to analyze tendencies of modern societies and science-fiction has offered richer symptoms than any other genre in the history of film industry. Usually exaggeration of "now" is the way to imagine "future" in science-fiction literature and cinema. So, this paper will give us the chance to discuss what are the current "body politics" drive modern people towards the dystopia of The Surrogates. Critical concepts of the above mentioned theorists/thinkers will be corner-stones of our experience for "practicing theory" around The Surrogates.

  10. Estimating Predictability Redundancy and Surrogate Data Method

    CERN Document Server

    Pecen, L

    1995-01-01

    A method for estimating theoretical predictability of time series is presented, based on information-theoretic functionals---redundancies and surrogate data technique. The redundancy, designed for a chosen model and a prediction horizon, evaluates amount of information between a model input (e.g., lagged versions of the series) and a model output (i.e., a series lagged by the prediction horizon from the model input) in number of bits. This value, however, is influenced by a method and precision of redundancy estimation and therefore it is a) normalized by maximum possible redundancy (given by the precision used), and b) compared to the redundancies obtained from two types of the surrogate data in order to obtain reliable classification of a series as either unpredictable or predictable. The type of predictability (linear or nonlinear) and its level can be further evaluated. The method is demonstrated using a numerically generated time series as well as high-frequency foreign exchange data and the theoretical ...

  11. A Method of Surrogate Model Construction which Leverages Lower-Fidelity Information using Space Mapping Techniques

    Science.gov (United States)

    2014-03-27

    errors found using the polynomial response surrogate (LS PRM ) overlaid on the data from the space-mapped (SM) surrogate...nonlinear space-mapped surrogate responses, with the least-squares PRM surrogate response plotted for comparison . . . . . . . . . . . . . . . . . 65 42...Percent error comparison between the least-squares space-mapping and the PRM surrogate models derived from samples in the second dataset

  12. Surrogate Modeling for Geometry Optimization in Material Design

    DEFF Research Database (Denmark)

    Rojas Larrazabal, Marielba de la Caridad; Abraham, Yonas B.; Holzwarth, Natalie A.W.;

    2007-01-01

    We propose a new approach based on surrogate modeling for geometry optimization in material design. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)......We propose a new approach based on surrogate modeling for geometry optimization in material design. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)...

  13. Human surrogate neck response to +Gz vertical impact

    NARCIS (Netherlands)

    Rooij, L. van; Uittenbogaard, J.

    2011-01-01

    For the evaluation of impact scenarios with a substantial vertical component, the performance of current human surrogates - the RID 3D hardware dummy and two numerical human models - was evaluated. Volunteer tests with 10G and 6G pulses were compared to reconstructed tests with human surrogates.

  14. Term clouds as surrogates for user generated speech

    NARCIS (Netherlands)

    M. Tsagkias; M. Larson; M. de Rijke

    2008-01-01

    User generated spoken audio remains a challenge for Automatic Speech Recognition (ASR) technology and content-based audio surrogates derived from ASR-transcripts must be error robust. An investigation of the use of term clouds as surrogates for podcasts demonstrates that ASR term clouds closely appr

  15. INTEC SBW Solid Sludge Surrogate Recipe and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Maio, Vince; Janikowski, Stuart; Johnson, Jim; Maio, Vince; Pao, Jenn-Hai

    2004-06-01

    A nonhazardous INTEC tank farm sludge surrogate that incorporated metathesis reactions to generate solids from solutions of known elements present in the radioactive INTEC tank farm sodium-bearing waste sludges was formulated. Elemental analyses, physical property analyses, and filtration testing were performed on waste surrogate and tank farm waste samples, and the results were compared. For testing physical systems associated with moving the tank farm solids, the surrogate described in this report is the best currently available choice. No other available surrogate exhibits the noted similarities in behavior to the sludges. The chemical morphology, particle size distribution, and settling and flow characteristics of the surrogate were similar to those exhibited by the waste sludges. Nonetheless, there is a difference in chemical makeup of the surrogate and the tank farm waste. If a chemical treatment process were to be evaluated for final treatment and disposition of the waste sludges, the surrogate synthesis process would likely require modification to yield a surrogate with a closer matching chemical composition.

  16. Inactivation of Tulane virus, a novel surrogate for human norovirus

    Science.gov (United States)

    Human noroviruses (HuNoVs) are the major cause of non-bacterial epidemics of gastroenteritis. Due to the inability to cultivate HuNoVs and the lack of an efficient small animal model, surrogates are used to study HuNoV biology. Two such surrogates, the feline calicivirus (FCV) and the murine norovir...

  17. Human surrogate neck response to +Gz vertical impact

    NARCIS (Netherlands)

    Rooij, L. van; Uittenbogaard, J.

    2011-01-01

    For the evaluation of impact scenarios with a substantial vertical component, the performance of current human surrogates - the RID 3D hardware dummy and two numerical human models - was evaluated. Volunteer tests with 10G and 6G pulses were compared to reconstructed tests with human surrogates. Add

  18. Space Mapping Optimization of Microwave Circuits Exploiting Surrogate Models

    DEFF Research Database (Denmark)

    Bakr, M. H.; Bandler, J. W.; Madsen, Kaj

    2000-01-01

    A powerful new space-mapping (SM) optimization algorithm is presented in this paper. It draws upon recent developments in both surrogate model-based optimization and modeling of microwave devices, SM optimization is formulated as a general optimization problem of a surrogate model. This model...

  19. Preclinical and human surrogate models of itch

    DEFF Research Database (Denmark)

    Hoeck, Emil August; Marker, Jens Broch; Gazerani, Parisa;

    2016-01-01

    Pruritus, or simply itch, is a debilitating symptom that significantly decreases the quality of life in a wide range of clinical conditions. While histamine remains the most studied mediator of itch in humans, treatment options for chronic itch, in particular antihistamine-resistant itch, are lim...... currently applied in animals and humans. This article is protected by copyright. All rights reserved.......Pruritus, or simply itch, is a debilitating symptom that significantly decreases the quality of life in a wide range of clinical conditions. While histamine remains the most studied mediator of itch in humans, treatment options for chronic itch, in particular antihistamine-resistant itch......, are limited. Relevant preclinical and human surrogate models of non-histaminergic itch are needed to accelerate the development of novel antipruritics and diagnostic tools. Advances in basic itch research have facilitated the development of diverse models of itch and associated dysesthesiae. While...

  20. Surrogates of plutonium for detection equipment testing

    Science.gov (United States)

    Peerani, Paolo; Tomanin, Alice

    2011-10-01

    Fight against illicit trafficking of nuclear material relies on the possibility to detect nuclear material concealed in vehicles, people or cargo containers. This is done by equipping and training law enforcement and security staff in border stations or other points of access to strategic places and critical infrastructures with radiation detection equipment. The design, development, testing and evaluation of these instruments ideally require the use of real nuclear material to assess, verify and certify their detection performance. Availability of special nuclear material may be an issue, especially for industry, since only few specialized laboratories are licensed for such material. This paper tries to analyse and describe the possibility to use suitable surrogates that may replace the use of real nuclear material in testing the detection capabilities of instruments used in nuclear security.

  1. Tractable Experiment Design via Mathematical Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Brian J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-29

    This presentation summarizes the development and implementation of quantitative design criteria motivated by targeted inference objectives for identifying new, potentially expensive computational or physical experiments. The first application is concerned with estimating features of quantities of interest arising from complex computational models, such as quantiles or failure probabilities. A sequential strategy is proposed for iterative refinement of the importance distributions used to efficiently sample the uncertain inputs to the computational model. In the second application, effective use of mathematical surrogates is investigated to help alleviate the analytical and numerical intractability often associated with Bayesian experiment design. This approach allows for the incorporation of prior information into the design process without the need for gross simplification of the design criterion. Illustrative examples of both design problems will be presented as an argument for the relevance of these research problems.

  2. Sheet metal forming optimization by using surrogate modeling techniques

    Science.gov (United States)

    Wang, Hu; Ye, Fan; Chen, Lei; Li, Enying

    2017-01-01

    Surrogate assisted optimization has been widely applied in sheet metal forming design due to its efficiency. Therefore, to improve the efficiency of design and reduce the product development cycle, it is important for scholars and engineers to have some insight into the performance of each surrogate assisted optimization method and make them more flexible practically. For this purpose, the state-of-the-art surrogate assisted optimizations are investigated. Furthermore, in view of the bottleneck and development of the surrogate assisted optimization and sheet metal forming design, some important issues on the surrogate assisted optimization in support of the sheet metal forming design are analyzed and discussed, involving the description of the sheet metal forming design, off-line and online sampling strategies, space mapping algorithm, high dimensional problems, robust design, some challenges and potential feasible methods. Generally, this paper provides insightful observations into the performance and potential development of these methods in sheet metal forming design.

  3. Labeling and preliminary in vivo assessment of niobium-labeled radioactive species: A proof-of-concept study.

    Science.gov (United States)

    Radchenko, Valery; Bouziotis, Penelope; Tsotakos, Theodoros; Paravatou-Petsotas, Mari; la Fuente, Ana de; Loudos, George; Harris, Adrian L; Xanthopoulos, Stavros; Filosofov, Dmitry; Hauser, Harald; Eisenhut, Michael; Ponsard, Bernard; Roesch, Frank

    2016-05-01

    The application of radionuclide-labeled biomolecules such as monoclonal antibodies or antibody fragments for imaging purposes is called immunoscintigraphy. More specifically, when the nuclides used are positron emitters, such as zirconium-89, the technique is referred to as immuno-PET. Currently, there is an urgent need for radionuclides with a half-life which correlates well with the biological kinetics of the biomolecules under question and which can be attached to the proteins by robust labeling chemistry. (90)Nb is a promising candidate for in vivo immuno-PET, due its half-life of 14.6h and low β(+) energy of Emean=0.35MeV per decay. (95)Nb on the other hand, is a convenient alternative for longer-term ex vivo biodistribution studies, due to its longer half-life of (t½=35days) and its convenient, lower-cost production (reactor-based production). In this proof-of-principle work, the monoclonal antibody bevacizumab (Avastin(®)) was labeled with (95/90)Nb and in vitro and in vivo stability was evaluated in normal Swiss mice and in tumor-bearing SCID mice. Initial ex vivo experiments with (95)Nb-bevacizumab showed adequate tumor uptake, however at the same time high uptake in the liver, spleen and kidneys was observed. In order to investigate whether this behavior is due to instability of (⁎)Nb-bevacizumab or to the creation of other (⁎)Nb species in vivo, we performed biodistribution studies of (95)Nb-oxalate, (95)Nb-chloride and (95)Nb-Df. These potential metabolite species did not show any specific uptake, apart from bone accumulation for (95)Nb-oxalate and (95)Nb-chloride, which, interestingly, may serve as an "indicator" for the release of (90)Nb from labeled biomolecules. Concerning the initial uptake of (95)Nb-bevacizumab in non-tumor tissue, biodistribution of a higher specific activity radiolabeled antibody sample did show only negligible uptake in the liver, spleen, kidneys or bones. In-vivo imaging of a tumor-bearing SCID mouse after injection

  4. Radiation Protection of Environment under the Light of the New Concept of Radiation Protection of Non-Human Species

    Energy Technology Data Exchange (ETDEWEB)

    Hansruedi Voelkle [Swiss Federal Office of Public Health, Environmental Radioactivity Section, c/o Physics Department, University of Fribourg Chemin du Musee 3, 1700 Fribourg (Switzerland)

    2006-07-01

    The purpose of this presentation is to discuss the question of whether radiation protection should be extended to plants and animals. Until now the recommendations of ICRP have been focused exclusively on the protection of man from ionizing radiation. It was assumed that, if man is protected, the quality of the living environment is not impaired. In recent years adequate principles, recommendations and laws have become necessary in order to protect the environment from man made toxins. These recommendations aimed to conserve plants and animals, to maintain the diversity of species, the health and status of natural habitats and the natural resources of our planet, to warrant natural evolution and selection processes in order to transmit a healthy world to future generations. Reflections have been made as to whether particular protection of fauna and flora from ionizing radiation should be included. This article presents some considerations from the point of view of operational radiation protection and some comments to the work already done by ICRP committee 5. The final purpose is to invite the audience to make its own reflections and to communicate any criticisms, comments or suggestions to committee 5 of ICRP. (author)

  5. Application of biodiversity surrogates in rapid biodiversity assessment%替代指标在生物多样性快速评价中的应用

    Institute of Scientific and Technical Information of China (English)

    李昊民; 罗咏梅; 王四海; 杨宇明

    2011-01-01

    生物多样性评价工作是生物多样性保护的基础,而替代指标的应用是在环境影响评价中实现生物多样性快速评价的重要方法之一.本文介绍了生物多样性替代指标的概念,分析了不同生物类群之间广泛存在的相关性,总结了大尺度上兽类、鸟类、维管束植物物种数的经验比例(1:5:50).对目前可供使用的生物多样性替代指标进行了系统整理和分类,将其划分为生物类替代指标(包括指示类群、功能类群和珍稀濒危类群)和生境类替代指标(包括环境因子、景观格局和自然圣境).对不同指标的替代机理、有效性、使用方法和适用范围等进行了归纳,探讨了增强生物多样性替代指标应用有效性和评价精度的主要途径.研究可为保护地规划、生物多样性监测和环境影响评价等领域开展生物多样性快速评价,以及环境评价制度中生物多样性影响评价的完善提供参考.%Biodiversity assessment is the basis for biodiversity conservation, while the application of biodiversity surrogate is one of the important means for quick biodiversity assessment in environmental impact assessment. This paper introduced the conception of biodiversity surrogate, analyzed the correlations widely existed among biological groups, and summarized the large scale experimental proportions among the species of mammals , birds and vascular plants ( 1 : 5 : 50 ) . The existing biodiversity surrogates were classified into two categories, i. e. , bio-surrogates ( indicator group, functional group, and rare and endangered group) and habitat-based surrogates (environmental factors, landscape features, and sacred natural sites). Also, the surrogating mechanisms, effectiveness, use methods, and use scope of different indicators were summarized, and the potential ways to improve the surrogates’ performance were discussed. This paper provided references for conservation site planning, biodiversity

  6. Surrogate model approach for improving the performance of reactive transport simulations

    Science.gov (United States)

    Jatnieks, Janis; De Lucia, Marco; Sips, Mike; Dransch, Doris

    2016-04-01

    (MARS) method provides the best trade-off between speed and accuracy. This proof-of-concept forms an essential step towards building an interactive visual analytics system to enable user-driven systematic creation of geochemical surrogate models. Such a system shall enable reactive transport simulations with unprecedented spatial and temporal detail to become possible. References: Kolditz, O., Görke, U.J., Shao, H. and Wang, W., 2012. Thermo-hydro-mechanical-chemical processes in porous media: benchmarks and examples (Vol. 86). Springer Science & Business Media.

  7. Surrogate/spent fuel sabotage : aerosol ratio test program and Phase 2 test results.

    Energy Technology Data Exchange (ETDEWEB)

    Borek, Theodore Thaddeus III; Thompson, N. Slater (U.S. Department of Energy); Sorenson, Ken Bryce; Hibbs, R.S. (U.S. Department of Energy); Nolte, Oliver (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Molecke, Martin Alan; Autrusson, Bruno (Institut de Radioprotection et de Surete Nucleaire, France); Young, F. I. (U.S. Nuclear Regulatory Commission); Koch, Wolfgang (Fraunhofer Institut fur Toxikologie und Experimentelle Medizin, Germany); Brochard, Didier (Institut de Radioprotection et de Surete Nucleaire, France); Pretzsch, Gunter Guido (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany); Lange, Florentin (Gesellschaft fur Anlagen- und Reaktorsicherheit, Germany)

    2004-05-01

    A multinational test program is in progress to quantify the aerosol particulates produced when a high energy density device, HEDD, impacts surrogate material and actual spent fuel test rodlets. This program provides needed data that are relevant to some sabotage scenarios in relation to spent fuel transport and storage casks, and associated risk assessments; the program also provides significant political benefits in international cooperation. We are quantifying the spent fuel ratio, SFR, the ratio of the aerosol particles released from HEDD-impacted actual spent fuel to the aerosol particles produced from surrogate materials, measured under closely matched test conditions. In addition, we are measuring the amounts, nuclide content, size distribution of the released aerosol materials, and enhanced sorption of volatile fission product nuclides onto specific aerosol particle size fractions. These data are crucial for predicting radiological impacts. This document includes a thorough description of the test program, including the current, detailed test plan, concept and design, plus a description of all test components, and requirements for future components and related nuclear facility needs. It also serves as a program status report as of the end of FY 2003. All available test results, observations, and analyses - primarily for surrogate material Phase 2 tests using cerium oxide sintered ceramic pellets are included. This spent fuel sabotage - aerosol test program is coordinated with the international Working Group for Sabotage Concerns of Transport and Storage Casks, WGSTSC, and supported by both the U.S. Department of Energy and Nuclear Regulatory Commission.

  8. The effectiveness of marine reserve systems constructed using different surrogates of biodiversity.

    Science.gov (United States)

    Sutcliffe, P R; Klein, C J; Pitcher, C R; Possingham, H P

    2015-06-01

    Biological sampling in marine systems is often limited, and the cost of acquiring new data is high. We sought to assess whether systematic reserves designed using abiotic domains adequately conserve a comprehensive range of species in a tropical marine inter-reef system. We based our assessment on data from the Great Barrier Reef, Australia. We designed reserve systems aiming to conserve 30% of each species based on 4 abiotic surrogate types (abiotic domains; weighted abiotic domains; pre-defined bioregions; and random selection of areas). We evaluated each surrogate in scenarios with and without cost (cost to fishery) and clumping (size of conservation area) constraints. To measure the efficacy of each reserve system for conservation purposes, we evaluated how well 842 species collected at 1155 sites across the Great Barrier Reef seabed were represented in each reserve system. When reserve design included both cost and clumping constraints, the mean proportion of species reaching the conservation target was 20-27% higher for reserve systems that were biologically informed than reserves designed using unweighted environmental data. All domains performed substantially better than random, except when there were no spatial or economic constraints placed on the system design. Under the scenario with no constraints, the mean proportion of species reaching the conservation target ranged from 98.5% to 99.99% across all surrogate domains, whereas the range was 90-96% across all domains when both cost and clumping were considered. This proportion did not change considerably between scenarios where one constraint was imposed and scenarios where both cost and clumping constraints were considered. We conclude that representative reserve systems can be designed using abiotic domains; however, there are substantial benefits if some biological information is incorporated. © 2015 Society for Conservation Biology.

  9. Mother-daughter in vitro fertilization triplet surrogate pregnancy.

    Science.gov (United States)

    Michelow, M C; Bernstein, J; Jacobson, M J; McLoughlin, J L; Rubenstein, D; Hacking, A I; Preddy, S; Van der Wat, I J

    1988-02-01

    A successful triplet pregnancy has been established in a surrogate gestational mother following the transfer of five embryos fertilized in vitro. The oocytes were donated by her biological daughter, and the sperm obtained from the daughter's husband. The daughter's infertility followed a total abdominal hysterectomy performed for a postpartum hemorrhage as a result of a placenta accreta. Synchronization of both their menstrual cycles was obtained using oral contraceptive suppression for 2 months, followed by stimulation of both the surrogate gestational mother and her daughter such that embryo transfer would occur at least 48 hr after the surrogate gestational mother's own ovulation. This case raises a number of medical, social, psychological, and ethical issues.

  10. SURROGATE MOTHER DALAM PERSPEKTIF HUKUM PIDANA INDONESIA

    Directory of Open Access Journals (Sweden)

    Mr. Muntaha

    2013-04-01

    Full Text Available The development of science and technology, in particular in the field of health, has already recently brought a huge advantage and problem in human life. An example of technological marvel that not only requires deep legal thoughts but also at the same time solution is the bio-medical technology advancement of surrogacy. Surrogacy deals with human’s inclination towards reproductive activity. However, it opens up legal complication, in particular with regards to the potential commission of a criminal action as well as to the notion of doctor’s liability. Perkembangan ilmu dan teknologi di bidang kesehatan yang semakin maju dan pesat telah membawa berbagai manfaat dan masalah dalam kehidupan manusia dewasa ini. Salah satu perkembangan yang tidak hanya membutuhkan pemikiran di bidang hukum, tetapi juga sekaligus solusinya adalah mengenai kecanggihan teknologi bio-medis surrogate mother. Surrogacy menyentuh sisi kemanusiaan seorang insan terhadap reproduksi. Akan tetapi, lembaga surrogacy juga membawa komplikasi hukum terutama terkait dengan potensi tindak pidana dan dengan persoalan tanggung jawab dokter.

  11. Polynomial Chaos Surrogates for Bayesian Inference

    KAUST Repository

    Le Maitre, Olivier

    2016-01-06

    The Bayesian inference is a popular probabilistic method to solve inverse problems, such as the identification of field parameter in a PDE model. The inference rely on the Bayes rule to update the prior density of the sought field, from observations, and derive its posterior distribution. In most cases the posterior distribution has no explicit form and has to be sampled, for instance using a Markov-Chain Monte Carlo method. In practice the prior field parameter is decomposed and truncated (e.g. by means of Karhunen- Lo´eve decomposition) to recast the inference problem into the inference of a finite number of coordinates. Although proved effective in many situations, the Bayesian inference as sketched above faces several difficulties requiring improvements. First, sampling the posterior can be a extremely costly task as it requires multiple resolutions of the PDE model for different values of the field parameter. Second, when the observations are not very much informative, the inferred parameter field can highly depends on its prior which can be somehow arbitrary. These issues have motivated the introduction of reduced modeling or surrogates for the (approximate) determination of the parametrized PDE solution and hyperparameters in the description of the prior field. Our contribution focuses on recent developments in these two directions: the acceleration of the posterior sampling by means of Polynomial Chaos expansions and the efficient treatment of parametrized covariance functions for the prior field. We also discuss the possibility of making such approach adaptive to further improve its efficiency.

  12. A Large-Scale Study of Surrogate Physicality and Gesturing on Human–Surrogate Interactions in a Public Space

    Directory of Open Access Journals (Sweden)

    Kangsoo Kim

    2017-07-01

    Full Text Available Technological human surrogates, including robotic and virtual humans, have been popularly used in various scenarios, including training, education, and entertainment. Prior research has investigated the effects of the surrogate’s physicality and gesturing in human perceptions and social influence of the surrogate. However, those studies have been carried out in research laboratories, where the participants were aware that it was an experiment, and the participant demographics are typically relatively narrow—e.g., college students. In this paper, we describe and share results from a large-scale exploratory user study involving 7,685 people in a public space, where they were unaware of the experimental nature of the setting, to investigate the effects of surrogate physicality and gesturing on their behavior during human–surrogate interactions. We evaluate human behaviors using several variables, such as proactivity and reactivity, and proximity. We have identified several interesting phenomena that could lead to hypotheses developed as part of future hypothesis-based studies. Based on the measurements of the variables, we believe people are more likely to be engaged in a human–surrogate interaction when the surrogate is physically present, but movements and gesturing with its body parts have not shown the expected benefits for the interaction engagement. Regarding the demographics of the people in the study, we found higher overall engagement for females than males, and higher reactivity for younger than older people. We discuss implications for practitioners aiming to design a technological surrogate that will directly interact with real humans.

  13. Hepatology may have problems with putative surrogate outcome measures

    DEFF Research Database (Denmark)

    Gluud, Christian; Brok, Jesper; Gong, Yan;

    2007-01-01

    hepatitis C, serum bilirubin concentration following ursodeoxycholic acid or immunosuppressants for patients with primary biliary cirrhosis, and nutritional outcomes following artificial nutrition for liver patients may not be valid surrogates for morbidity or mortality. The challenge is to develop reliable...

  14. Fernald Silos 1 & 2 Accelerated Waste Retrieval Program Surrogate Development

    Energy Technology Data Exchange (ETDEWEB)

    Mullen, O Dennis; Erian, Fadel F.

    2002-09-01

    Whitepaper describing the rationale and methodology for development of surrogates to be used for testing retrieval and processing systems for the DOE Fernald Silos 1 & 2 wastes. One significant updating/revision is expected.

  15. THE SURROGATE COLONIZATION OF PALESTINE, 1917-1939

    OpenAIRE

    Atran, Scott

    1989-01-01

    The "surrogate colonization" of Palestine had a foreign power giving to a nonnative group rights over land occupied by an indigenous people. It thus brought into play the complementary and conflicting agendas of three culturally distinguishable parties: British, Jews and Arabs. Each party had both "externalist" [those with no sustained practical experience of day to day life in Palestine] and "internalist" representatives. The surrogate idea was based on a "strategic consensus" involving each...

  16. Surrogate nutrition markers, malnutrition, and adequacy of nutrition support.

    Science.gov (United States)

    Seres, David S

    2005-06-01

    Surrogate nutrition markers are used to assess adequacy of nourishment and to define malnutrition despite evidence that fails to link nourishment, surrogate markers, and outcomes. Markers such as serum levels of albumin, prealbumin, transferrin, and IGF-1 and delayed hypersensitivity and total lymphocyte count may be valid to help stratify risk. However, it is not appropriate to consider these as markers of adequacy of nourishment in the sick patient.

  17. Emotional experiences in surrogate mothers: A qualitative study

    OpenAIRE

    Hoda Ahmari Tehran; Shohreh Tashi; Nahid Mehran; Narges Eskandari; Tahmineh Dadkhah Tehrani

    2014-01-01

    Background: Surrogacy is one of the new techniques of assisted reproduction technology in which a woman carries and bears a child for another woman. In Iran, many Shia clerics and jurists considered it permissible so there is no religious prohibition for it. In addition to the risk of physical complications for complete surrogate mothers, the possibility of psychological complications resulted from emotional attachment to a living creature in the surrogate mother as another injury requires co...

  18. Human surrogate models of neuropathic pain: validity and limitations.

    Science.gov (United States)

    Binder, Andreas

    2016-02-01

    Human surrogate models of neuropathic pain in healthy subjects are used to study symptoms, signs, and the hypothesized underlying mechanisms. Although different models are available, different spontaneous and evoked symptoms and signs are inducible; 2 key questions need to be answered: are human surrogate models conceptually valid, ie, do they share the sensory phenotype of neuropathic pain states, and are they sufficiently reliable to allow consistent translational research?

  19. Magnetometer Response of Commonly Found Munitions Items and Munitions Surrogates

    Science.gov (United States)

    2012-01-12

    Predicted minimum magnetometer anomaly strength for a variety of munitions and surrogate items at a burial depth corresponding to 11x their respective...Response Live Site Demonstrations. The authors would like to thank Craig Murray of Parsons and Stephen Billings of Sky Research for their...variety of munitions and surrogate items at a burial depth corresponding to 11x their respective diameter. The sensor is assumed to be deployed as part

  20. Skeletal mechanism generation for surrogate fuels using directed relation graph with error propagation and sensitivity analysis

    CERN Document Server

    Niemeyer, Kyle E; Raju, Mandhapati P

    2016-01-01

    A novel implementation for the skeletal reduction of large detailed reaction mechanisms using the directed relation graph with error propagation and sensitivity analysis (DRGEPSA) is developed and presented with examples for three hydrocarbon components, n-heptane, iso-octane, and n-decane, relevant to surrogate fuel development. DRGEPSA integrates two previously developed methods, directed relation graph-aided sensitivity analysis (DRGASA) and directed relation graph with error propagation (DRGEP), by first applying DRGEP to efficiently remove many unimportant species prior to sensitivity analysis to further remove unimportant species, producing an optimally small skeletal mechanism for a given error limit. It is illustrated that the combination of the DRGEP and DRGASA methods allows the DRGEPSA approach to overcome the weaknesses of each, specifically that DRGEP cannot identify all unimportant species and that DRGASA shields unimportant species from removal. Skeletal mechanisms for n-heptane and iso-octane ...

  1. Financial Surrogate Decision Making: Lessons from Applied Experimental Philosophy.

    Science.gov (United States)

    Feltz, Adam

    2016-09-20

    An estimated 1 in 4 elderly Americans need a surrogate to make decisions at least once in their lives. With an aging population, that number is almost certainly going to increase. This paper focuses on financial surrogate decision making. To illustrate some of the empirical and moral implications associated with financial surrogate decision making, two experiments suggest that default choice settings can predictably influence some surrogate financial decision making. Experiment 1 suggested that when making hypothetical financial decisions, surrogates tended to stay with default settings (OR = 4.37, 95% CI 1.52, 12.48). Experiment 2 replicated and extended this finding suggesting that in a different context (OR = 2.27, 95% CI 1.1, 4.65). Experiment 2 also suggested that those who were more numerate were less likely to be influenced by default settings than the less numerate, but only when the decision is whether to "opt in" (p = .05). These data highlight the importance of a recent debate about "nudging." Defaults are common methods to nudge people to make desirable choices while allowing the liberty to choose otherwise. Some of the ethics of using default settings to nudge surrogate decision makers are discussed.

  2. Reliability-based design optimization with progressive surrogate models

    Science.gov (United States)

    Kanakasabai, Pugazhendhi; Dhingra, Anoop K.

    2014-12-01

    Reliability-based design optimization (RBDO) has traditionally been solved as a nested (bilevel) optimization problem, which is a computationally expensive approach. Unilevel and decoupled approaches for solving the RBDO problem have also been suggested in the past to improve the computational efficiency. However, these approaches also require a large number of response evaluations during optimization. To alleviate the computational burden, surrogate models have been used for reliability evaluation. These approaches involve construction of surrogate models for the reliability computation at each point visited by the optimizer in the design variable space. In this article, a novel approach to solving the RBDO problem is proposed based on a progressive sensitivity surrogate model. The sensitivity surrogate models are built in the design variable space outside the optimization loop using the kriging method or the moving least squares (MLS) method based on sample points generated from low-discrepancy sampling (LDS) to estimate the most probable point of failure (MPP). During the iterative deterministic optimization, the MPP is estimated from the surrogate model for each design point visited by the optimizer. The surrogate sensitivity model is also progressively updated for each new iteration of deterministic optimization by adding new points and their responses. Four example problems are presented showing the relative merits of the kriging and MLS approaches and the overall accuracy and improved efficiency of the proposed approach.

  3. Coming to terms with the concept of moving species threatened by climate change - a systematic review of the terminology and definitions.

    Science.gov (United States)

    Hällfors, Maria H; Vaara, Elina M; Hyvärinen, Marko; Oksanen, Markku; Schulman, Leif E; Siipi, Helena; Lehvävirta, Susanna

    2014-01-01

    Intentional moving of species threatened by climate change is actively being discussed as a conservation approach. The debate, empirical studies, and policy development, however, are impeded by an inconsistent articulation of the idea. The discrepancy is demonstrated by the varying use of terms, such as assisted migration, assisted colonisation, or managed relocation, and their multiple definitions. Since this conservation approach is novel, and may for instance lead to legislative changes, it is important to aim for terminological consistency. The objective of this study is to analyse the suitability of terms and definitions used when discussing the moving of organisms as a response to climate change. An extensive literature search and review of the material (868 scientific publications) was conducted for finding hitherto used terms (N = 40) and definitions (N = 75), and these were analysed for their suitability. Based on the findings, it is argued that an appropriate term for a conservation approach relating to aiding the movement of organisms harmed by climate change is assisted migration defined as follows: Assisted migration means safeguarding biological diversity through the translocation of representatives of a species or population harmed by climate change to an area outside the indigenous range of that unit where it would be predicted to move as climate changes, were it not for anthropogenic dispersal barriers or lack of time. The differences between assisted migration and other conservation translocations are also discussed. A wide adoption of the clear and distinctive term and definition provided would allow more focused research on the topic and enable consistent implementation as practitioners could have the same understanding of the concept.

  4. 装备采购招标代理工作管理%Management of Equipment Procurement Tendering Surrogate Work

    Institute of Scientific and Technical Information of China (English)

    周静; 李晓松; 刘杰

    2016-01-01

    The paper defines the concept of equipment procurement tendering surrogate and analyzes the necessity of introducing tendering surrogate into equipment procurement.Combined with the main prac-tices and existing problems,it puts forward the general ideas and specific measures on how to strengthen the management of equipment procurement tendering surrogate work,which provides reference for the sci-entific management of equipment procurement tendering surrogate organizations.%界定了装备采购招标代理的概念,分析了装备采购引入招标代理的必要性,结合目前装备采购招标代理的主要做法及存在问题,提出了加强装备采购招标代理工作管理的总体思路与具体举措,为实现装备采购招标代理机构的科学管理提供参考。

  5. Taxonomic and functional surrogates of sessile benthic diversity in Mediterranean marine caves.

    Science.gov (United States)

    Gerovasileiou, Vasilis; Dimitriadis, Charalampos; Arvanitidis, Christos; Voultsiadou, Eleni

    2017-01-01

    Hard substrates host globally a rich biodiversity, orders of magnitude higher in species number than that in surrounding soft substrates. Among them, marine caves support unique biodiversity and fragile communities but suffer lack of quantitative data on their structure and function, hindering their conservation status assessment. A first approach to the non-destructive ecological monitoring of marine caves by testing surrogates of structural and functional composition of sessile benthos was attempted in two species-rich Mediterranean marine caves. Photographic sampling was performed in different positions on the cave walls, across the horizontal axis, from the entrance inwards. Eighty-four taxa were identified and assigned to 6 biological traits and 32 modalities related to morphology, behavior and ecological affinities, with sponges being the dominant taxon in species richness and coverage. In quest of possible biological surrogates, we examined the spatial variability of the total community structure and function and separately the sponge community structure and function. The observed patterns of the above metrics were significantly correlated with the distance from the entrance, the small-scale variability and their interaction. A positive correlation was found between all examined pairs of those metrics, supporting that: (i) the developed functional approach could be used for the study of marine cave sessile communities, and (ii) sponges could be used as a surrogate taxon for the structural and functional study of these communities. The suggested method could be tested in other types of hard substrate habitats and in multiple locations of the Mediterranean waters, facilitating monitoring schemes and conservation actions.

  6. Beyond multi-fractals: surrogate time series and fields

    Science.gov (United States)

    Venema, V.; Simmer, C.

    2007-12-01

    Most natural complex are characterised by variability on a large range of temporal and spatial scales. The two main methodologies to generate such structures are Fourier/FARIMA based algorithms and multifractal methods. The former is restricted to Gaussian data, whereas the latter requires the structure to be self-similar. This work will present so-called surrogate data as an alternative that works with any (empirical) distribution and power spectrum. The best-known surrogate algorithm is the iterative amplitude adjusted Fourier transform (IAAFT) algorithm. We have studied six different geophysical time series (two clouds, runoff of a small and a large river, temperature and rain) and their surrogates. The power spectra and consequently the 2nd order structure functions were replicated accurately. Even the fourth order structure function was more accurately reproduced by the surrogates as would be possible by a fractal method, because the measured structure deviated too strong from fractal scaling. Only in case of the daily rain sums a fractal method could have been more accurate. Just as Fourier and multifractal methods, the current surrogates are not able to model the asymmetric increment distributions observed for runoff, i.e., they cannot reproduce nonlinear dynamical processes that are asymmetric in time. Furthermore, we have found differences for the structure functions on small scales. Surrogate methods are especially valuable for empirical studies, because the time series and fields that are generated are able to mimic measured variables accurately. Our main application is radiative transfer through structured clouds. Like many geophysical fields, clouds can only be sampled sparsely, e.g. with in-situ airborne instruments. However, for radiative transfer calculations we need full 3-dimensional cloud fields. A first study relating the measured properties of the cloud droplets and the radiative properties of the cloud field by generating surrogate cloud

  7. Occupancy as a surrogate for abundance estimation

    Directory of Open Access Journals (Sweden)

    MacKenzie, D. I.

    2004-06-01

    Full Text Available In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of detectability must be taken into account in order to make accurate inferences: the non-detection of the species does not imply the species is genuinely absent. Here we review some recent modelling developments that permit unbiased estimation of the proportion of area occupied, colonization and local extinction probabilities. These methods allow for unequal sampling effort and enable covariate information on sampling locations to be incorporated. We also describe how these models could be extended to incorporate information from marked individuals, which would enable finer questions of population dynamics (such as turnover rate of nest sites by specific breeding pairs to be addressed. We believe these models may be applicable to a wide range of bird species and may be useful for investigating various questions of ecological interest. For example, with respect to habitat quality, we might predict that a species is more likely to have higher local extinction probabilities, or higher turnover rates of specific breeding pairs, in poor quality habitats.

  8. Surrogate Modeling of Deformable Joint Contact using Artificial Neural Networks

    Science.gov (United States)

    Eskinazi, Ilan; Fregly, Benjamin J.

    2016-01-01

    Deformable joint contact models can be used to estimate loading conditions for cartilage-cartilage, implant-implant, human-orthotic, and foot-ground interactions. However, contact evaluations are often so expensive computationally that they can be prohibitive for simulations or optimizations requiring thousands or even millions of contact evaluations. To overcome this limitation, we developed a novel surrogate contact modeling method based on artificial neural networks (ANNs). The method uses special sampling techniques to gather input-output data points from an original (slow) contact model in multiple domains of input space, where each domain represents a different physical situation likely to be encountered. For each contact force and torque output by the original contact model, a multi-layer feed-forward ANN is defined, trained, and incorporated into a surrogate contact model. As an evaluation problem, we created an ANN-based surrogate contact model of an artificial tibiofemoral joint using over 75,000 evaluations of a fine-grid elastic foundation (EF) contact model. The surrogate contact model computed contact forces and torques about 1000 times faster than a less accurate coarse grid EF contact model. Furthermore, the surrogate contact model was seven times more accurate than the coarse grid EF contact model within the input domain of a walking motion. For larger input domains, the surrogate contact model showed the expected trend of increasing error with increasing domain size. In addition, the surrogate contact model was able to identify out-of-contact situations with high accuracy. Computational contact models created using our proposed ANN approach may remove an important computational bottleneck from musculoskeletal simulations or optimizations incorporating deformable joint contact models. PMID:26220591

  9. Habitats as Surrogates of Taxonomic and Functional Fish Assemblages in Coral Reef Ecosystems: A Critical Analysis of Factors Driving Effectiveness

    Science.gov (United States)

    Van Wynsberge, Simon; Andréfouët, Serge; Hamel, Mélanie A.; Kulbicki, Michel

    2012-01-01

    Species check-lists are helpful to establish Marine Protected Areas (MPAs) and protect local richness, endemicity, rarity, and biodiversity in general. However, such exhaustive taxonomic lists (i.e., true surrogate of biodiversity) require extensive and expensive censuses, and the use of estimator surrogates (e.g., habitats) is an appealing alternative. In truth, surrogate effectiveness appears from the literature highly variable both in marine and terrestrial ecosystems, making it difficult to provide practical recommendations for managers. Here, we evaluate how the biodiversity reference data set and its inherent bias can influence effectiveness. Specifically, we defined habitats by geomorphology, rugosity, and benthic cover and architecture criteria, and mapped them with satellite images for a New-Caledonian site. Fish taxonomic and functional lists were elaborated from Underwater Visual Censuses, stratified according to geomorphology and exposure. We then tested if MPA networks designed to maximize habitat richness, diversity and rarity could also effectively maximize fish richness, diversity, and rarity. Effectiveness appeared highly sensitive to the fish census design itself, in relation to the type of habitat map used and the scale of analysis. Spatial distribution of habitats (estimator surrogate’s distribution), quantity and location of fish census stations (target surrogate’s sampling), and random processes in the MPA design all affected effectiveness to the point that one small change in the data set could lead to opposite conclusions. We suggest that previous conclusions on surrogacy effectiveness, either positive or negative, marine or terrestrial, should be considered with caution, except in instances where very dense data sets were used without pseudo-replication. Although this does not rule out the validity of using surrogates of species lists for conservation planning, the critical joint examination of both target and estimator surrogates is

  10. Interactions between Human Norovirus Surrogates and Acanthamoeba spp.

    Science.gov (United States)

    Hsueh, Tun-Yun; Gibson, Kristen E

    2015-06-15

    Human noroviruses (HuNoVs) are the most common cause of food-borne disease outbreaks, as well as virus-related waterborne disease outbreaks in the United States. Here, we hypothesize that common free-living amoebae (FLA)-ubiquitous in the environment, known to interact with pathogens, and frequently isolated from water and fresh produce-could potentially act as reservoirs of HuNoV and facilitate the environmental transmission of HuNoVs. To investigate FLA as reservoirs for HuNoV, the interactions between two Acanthamoeba species, A. castellanii and A. polyphaga, as well as two HuNoV surrogates, murine norovirus type 1 (MNV-1) and feline calicivirus (FCV), were evaluated. The results showed that after 1 h of amoeba-virus incubation at 25°C, 490 and 337 PFU of MNV-1/ml were recovered from A. castellanii and A. polyphaga, respectively, while only few or no FCVs were detected. In addition, prolonged interaction of MNV-1 with amoebae was investigated for a period of 8 days, and MNV-1 was demonstrated to remain stable at around 200 PFU/ml from day 2 to day 8 after virus inoculation in A. castellanii. Moreover, after a complete amoeba life cycle (i.e., encystment and excystment), infectious viruses could still be detected. To determine the location of virus associated with amoebae, immunofluorescence experiments were performed and showed MNV-1 transitioning from the amoeba surface to inside the amoeba over a 24-h period. These results are significant to the understanding of how HuNoVs may interact with other microorganisms in the environment in order to aid in its persistence and survival, as well as potential transmission in water and to vulnerable food products such as fresh produce.

  11. Reduced chemistry for a gasoline surrogate valid at engine-relevant conditions

    CERN Document Server

    Niemeyer, Kyle E

    2014-01-01

    A detailed mechanism for the four-component gasoline surrogate developed by Lawrence Livermore National Laboratory has shown good agreement with experiments in engine-relevant conditions. However, with 1388 species and 5933 reversible reactions, this detailed mechanism is far too large to use in practical engine simulations. Therefore, reduction of the detailed mechanism was performed using a multi-stage approach consisting of the DRGEPSA method, unimportant reaction elimination, isomer lumping, and analytic QSS reduction based on CSP analysis. A new greedy sensitivity analysis algorithm was developed and demonstrated to be capable of removing more species for the same error limit compared to the conventional sensitivity analysis used in DRG-based skeletal reduction methods. Using this new greedy algorithm, several skeletal and reduced mechanisms were developed at varying levels of complexity and for different target condition ranges. The final skeletal and reduced mechanisms consisted of 213 and 148 species,...

  12. Chlorinated and nitrogenous disinfection by-product formation from ozonation and post-chlorination of natural organic matter surrogates.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Rifai, Omar; Ali, Hussain; Graham, Nigel J D

    2014-09-01

    Ozonation before chlorination is associated with enhanced formation of chloropicrin, a halonitromethane disinfection by-product (DBP), during drinking water treatment. In order to elucidate reasons for this, five natural organic matter (NOM) surrogates were treated using both chlorination and ozonation-chlorination under controlled laboratory conditions. Selected surrogates comprised two phenolic compounds, two free amino acids and one dipeptide; these were resorcinol, 3-aminophenol, L-aspartic acid, β-alanine and ala-ala, respectively. Quantified DBPs included chloropicrin, chloroform, dichloroacetonitrile and trichloroacetonitrile. Relative to chlorination alone, increases in the formation of chloropicrin from ozonation-chlorination varied from 138% for 3-aminophenol to 3740% for ala-ala for the four amine surrogates. This indicates that ozone is more effective than chlorine in mediating a rate-limiting oxidation step in chloropicrin formation, most plausibly involving conversion of an amine group to a nitro group. While both hydrophilic and hydrophobic surrogates acted as chloropicrin precursors, ala-ala was the most reactive precursor following ozonation-chlorination. Since peptides are far commoner in drinking water sources than free amino acids, further research into chemical oxidation of these species by ozone and chlorine is recommended. In contrast, oxidation with ozone prior to chlorination reduced chloroform formation moderately for the two phenolic compounds.

  13. Biodegradation of naphthenic acid surrogates by axenic cultures.

    Science.gov (United States)

    Yue, Siqing; Ramsay, Bruce A; Ramsay, Juliana A

    2015-07-01

    This is the first study to report that bacteria from the genera Ochrobactrum, Brevundimonas and Bacillus can be isolated by growth on naphthenic acids (NAs) extracted from oil sands process water (OSPW). These pure cultures were screened for their ability to use a range of aliphatic, cyclic and aromatic NA surrogates in 96-well microtiter plates using water-soluble tetrazolium redox dyes (Biolog Redox Dye H) as the indicator of metabolic activity. Of the three cultures, Ochrobactrum showed most metabolic activity on the widest range of NA surrogates. Brevundomonas and especially Ochrobactrum had higher metabolic activity on polycyclic aromatic compounds than other classes of NA surrogates. Bacillus also oxidized a wide range of NA surrogates but not as well as Ochrobactrum. Using this method to characterize NA utilisation, one can identify which NAs or NA classes in OSPW are more readily degraded. Since aromatic NAs have been shown to have an estrogenic effect and polycyclic monoaromatic compounds have been suggested to pose the greatest environmental threat among the NAs, these bacterial genera may play an important role in detoxification of OSPW. Furthermore, this study demonstrates that bacteria belonging to the genera Ochrobactrum and Bacillus can also degrade surrogates of tricyclic NAs.

  14. Searching for Dynamical Earthquake Precursors with Surrogate Data

    Science.gov (United States)

    Lynch, J.; Revenaugh, J.; Georgopoulos, A.

    2007-12-01

    Surrogate data methods are resampling techniques related to the modern statistical bootstrap. The nonlinear dynamics community has promoted surrogate data as a useful tool for establishing the presence of nonlinear dynamics in experimental observations before applying more specific techniques such as nonlinear prediction. We propose to use surrogate data tests to search for evidence of transient nonlinear dynamics in seismographic data that act as a proxy for earthquake triggering mechanisms, such as fluid flow in the fault zone, failure cascades and slow prefatory slip, that signal changes in the coupling between geological boundaries. We will analyze the vertical component of broadband seismographic data recorded at 20Hz by the CI network of approximately 100 stations located throughout Southern California. We will focus on a period of six hours prior to seismic events of magnitude 4-5 located inside the CI network. Each seismographic record will be scanned for short, non-overlapping segments that pass a moderate stationarity criterion. We will then apply surrogate tests to each qualifying segment using three discriminating statistics: time reversal asymmetry, delay vector variance and zeroth-order nonlinear prediction error. We will correlate the results with known seismic activity and examine the spatial and temporal distribution of the surrogate test results for potential dynamical earthquake precursors.

  15. On the use of abiotic surrogates to describe marine benthic biodiversity

    Science.gov (United States)

    McArthur, M. A.; Brooke, B. P.; Przeslawski, R.; Ryan, D. A.; Lucieer, V. L.; Nichol, S.; McCallum, A. W.; Mellin, C.; Cresswell, I. D.; Radke, L. C.

    2010-06-01

    A growing need to manage marine biodiversity sustainably at local, regional and global scales cannot be met by applying existing biological data. Abiotic surrogates of biodiversity are thus increasingly valuable in filling the gaps in our knowledge of biodiversity patterns, especially identification of hotspots, habitats needed by endangered or commercially valuable species and systems or processes important to the sustained provision of ecosystem services. This review examines the use of abiotic variables as surrogates for patterns in benthic biodiversity with particular regard to how variables are tied to processes affecting species richness and how easily those variables can be measured at scales relevant to resource management decisions. Direct gradient variables such as salinity, oxygen concentration and temperature can be strong predictive variables for larger systems, although local stability of water quality may prevent usefulness of these factors at fine spatial scales. Biological productivity has complex relationships with benthic biodiversity and although the development of local and regional models cannot accurately predict outside the range of their biological sampling, remote sensing may provide useful information. Indeed, interpolated values are available for much of the world's seas, and these are continually being refined by the collection of remote sensing and field data. Sediment variables often exhibit complex relationships with benthic biodiversity. The strength of the relationship between any one sediment variable and biodiversity may depend on the state of another sediment variable in that system. Percentage mud, percentage gravel, rugosity and compaction hold the strongest independent predictive power. Rugosity and the difference between gravel and finer sediments can be established using acoustic methods, but to quantify grain size and measure compaction, a sample is necessary. Pure spatial variables such as latitude, longitude and depth

  16. Cross-taxon congruence in wetlands: Assessing the value of waterbirds as surrogates of macroinvertebrate biodiversity in Mediterranean Ramsar sites

    OpenAIRE

    Guareschi, Simone; Abellán,Pedro; Laini, A.; Green, Andy J.; Sánchez-Zapata, José A.; Velasco, Josefa; Millán,Andrés

    2015-01-01

    © 2014 Elsevier Ltd. All rights reserved. Wetlands are among the most threatened habitats and the species they support among the most endangered taxa. Measuring and monitoring wetland biodiversity is vital for conservation, restoration and management, and often relies on the use of surrogate taxa. Waterbirds are commonly used as flagships of biodiversity and are the subject of major conservation initiatives. Therefore, it is important to assess the extent to which waterbirds indicate the gene...

  17. Investigation of the anhydrous molten Na-B-O-H system and the concept: Electrolytic hydriding of sodium boron oxide species

    Energy Technology Data Exchange (ETDEWEB)

    Calabretta, Daniel L.; Davis, Boyd R. [Queen' s-RMC Fuel Cell Research Centre, Kingston, Ont. (Canada); Kingston Process Metallurgy, Inc., 1102 Lancaster Dr., Kingston, Ont. (Canada); Department of Mining Engineering, Queen' s University, 25 Union Ave., Kingston, Ont. (Canada)

    2007-02-10

    Although sodium borohydride (NaBH{sub 4}) can act as an excellent hydrogen storage material, its cost renders it impractical for automotive applications. In this paper the concept of electrolytic production of NaBH{sub 4} from sodium metaborate (NaBO{sub 2}) is introduced following a literature review of NaBH{sub 4} synthesis. By deduction, we assert that only by employing dense solid oxide ion electrolytes and a molten salt solution containing the two constituents would such a process be possible. We investigated the molten anhydrous Na-B-O-H system by pressure differential thermal analysis (PDTA), X-ray diffraction (XRD) and gas evolution analysis (GEA) using the starting reagents sodium hydride (NaH), NaBO{sub 2} and NaBH{sub 4}. We found that molten NaBH{sub 4} is not stable with NaBO{sub 2} above 600 C due to the formation of sodium orthoborate (Na{sub 4}B{sub 2}O{sub 5}), hydrogen and boron. However, the quasi-reciprocal ternary system, (4/5)NaH-NaBO{sub 2}-(1/5)NaBH{sub 4}-(2/5)Na{sub 4}B{sub 2}O{sub 5}, that was discovered, proves that molten Na{sub 4}B{sub 2}O{sub 5} is miscible and stable with molten NaBH{sub 4} to at least 650 C under the hydrogen pressures used in this study. As well, the compound Na{sub 6}B{sub 2}O{sub 5}H{sub 2} was discovered and a substantial portion of the anhydrous Na-B-O-H phase diagram has been experimentally deduced. There is a large ionic liquid composition domain within the system that would allow for the electrolytic hydriding of sodium boron oxide species to be tested. (author)

  18. Investigation of the anhydrous molten Na-B-O-H system and the concept: Electrolytic hydriding of sodium boron oxide species

    Science.gov (United States)

    Calabretta, Daniel L.; Davis, Boyd R.

    Although sodium borohydride (NaBH 4) can act as an excellent hydrogen storage material, its cost renders it impractical for automotive applications. In this paper the concept of electrolytic production of NaBH 4 from sodium metaborate (NaBO 2) is introduced following a literature review of NaBH 4 synthesis. By deduction, we assert that only by employing dense solid oxide ion electrolytes and a molten salt solution containing the two constituents would such a process be possible. We investigated the molten anhydrous Na-B-O-H system by pressure differential thermal analysis (PDTA), X-ray diffraction (XRD) and gas evolution analysis (GEA) using the starting reagents sodium hydride (NaH), NaBO 2 and NaBH 4. We found that molten NaBH 4 is not stable with NaBO 2 above 600 °C due to the formation of sodium orthoborate (Na 4B 2O 5), hydrogen and boron. However, the quasi-reciprocal ternary system, (4/5)NaH-NaBO 2-(1/5)NaBH 4-(2/5)Na 4B 2O 5, that was discovered, proves that molten Na 4B 2O 5 is miscible and stable with molten NaBH 4 to at least 650 °C under the hydrogen pressures used in this study. As well, the compound Na 6B 2O 5H 2 was discovered and a substantial portion of the anhydrous Na-B-O-H phase diagram has been experimentally deduced. There is a large ionic liquid composition domain within the system that would allow for the electrolytic hydriding of sodium boron oxide species to be tested.

  19. Use of habitats as surrogates of biodiversity for efficient coral reef conservation planning in Pacific Ocean islands.

    Science.gov (United States)

    Dalleau, Mayeul; Andréfouët, Serge; Wabnitz, Colette C C; Payri, Claude; Wantiez, Laurent; Pichon, Michel; Friedman, Kim; Vigliola, Laurent; Benzoni, Francesca

    2010-04-01

    Marine protected areas (MPAs) have been highlighted as a means toward effective conservation of coral reefs. New strategies are required to more effectively select MPA locations and increase the pace of their implementation. Many criteria exist to design MPA networks, but generally, it is recommended that networks conserve a diversity of species selected for, among other attributes, their representativeness, rarity, or endemicity. Because knowledge of species' spatial distribution remains scarce, efficient surrogates are urgently needed. We used five different levels of habitat maps and six spatial scales of analysis to identify under which circumstances habitat data used to design MPA networks for Wallis Island provided better representation of species than random choice alone. Protected-area site selections were derived from a rarity-complementarity algorithm. Habitat surrogacy was tested for commercial fish species, all fish species, commercially harvested invertebrates, corals, and algae species. Efficiency of habitat surrogacy varied by species group, type of habitat map, and spatial scale of analysis. Maps with the highest habitat thematic complexity provided better surrogates than simpler maps and were more robust to changes in spatial scales. Surrogates were most efficient for commercial fishes, corals, and algae but not for commercial invertebrates. Conversely, other measurements of species-habitat associations, such as richness congruence and composition similarities provided weak results. We provide, in part, a habitat-mapping methodology for designation of MPAs for Pacific Ocean islands that are characterized by habitat zonations similar to Wallis. Given the increasing availability and affordability of space-borne imagery to map habitats, our approach could appreciably facilitate and improve current approaches to coral reef conservation and enhance MPA implementation.

  20. Love as a regulative ideal in surrogate decision making.

    Science.gov (United States)

    Stonestreet, Erica Lucast

    2014-10-01

    This discussion aims to give a normative theoretical basis for a "best judgment" model of surrogate decision making rooted in a regulative ideal of love. Currently, there are two basic models of surrogate decision making for incompetent patients: the "substituted judgment" model and the "best interests" model. The former draws on the value of autonomy and responds with respect; the latter draws on the value of welfare and responds with beneficence. It can be difficult to determine which of these two models is more appropriate for a given patient, and both approaches may seem inadequate for a surrogate who loves the patient. The proposed "best judgment" model effectively draws on the values incorporated in each of the traditional standards, but does so because these values are important to someone who loves a patient, since love responds to the patient as the specific person she is.

  1. Surrogate modeling for initial rotational stiffness of welded tubular joints

    Directory of Open Access Journals (Sweden)

    M.R. Garifullin

    2016-10-01

    Full Text Available Recently, buildings and structures erected in Russia and abroad have to comply with stringent economic requirements. Buildings should not only be reliable and safe, have a beautiful architectural design, but also meet the criteria of rationality and energy efficiency. In practice, this usually means the need for additional comparative analysis in order to determine the optimal solution to the engineering task. Usually such an analysis is time-consuming and requires huge computational efforts. In this regard, surrogate modeling can be an effective tool for solving such problems. This article provides a brief description of surrogate models and the basic techniques of their construction, describes the construction process of a surrogate model to calculate initial rotational stiffness of welded RHS joints made of high strength steel (HSS.

  2. Isotope Inversion Experiment evaluating the suitability of calibration in surrogate matrix for quantification via LC-MS/MS-Exemplary application for a steroid multi-method.

    Science.gov (United States)

    Suhr, Anna Catharina; Vogeser, Michael; Grimm, Stefanie H

    2016-05-30

    For quotable quantitative analysis of endogenous analytes in complex biological samples by isotope dilution LC-MS/MS, the creation of appropriate calibrators is a challenge, since analyte-free authentic material is in general not available. Thus, surrogate matrices are often used to prepare calibrators and controls. However, currently employed validation protocols do not include specific experiments to verify the suitability of a surrogate matrix calibration for quantification of authentic matrix samples. The aim of the study was the development of a novel validation experiment to test whether surrogate matrix based calibrators enable correct quantification of authentic matrix samples. The key element of the novel validation experiment is the inversion of nonlabelled analytes and their stable isotope labelled (SIL) counterparts in respect to their functions, i.e. SIL compound is the analyte and nonlabelled substance is employed as internal standard. As a consequence, both surrogate and authentic matrix are analyte-free regarding SIL analytes, which allows a comparison of both matrices. We called this approach Isotope Inversion Experiment. As figure of merit we defined the accuracy of inverse quality controls in authentic matrix quantified by means of a surrogate matrix calibration curve. As a proof-of-concept application a LC-MS/MS assay addressing six corticosteroids (cortisol, cortisone, corticosterone, 11-deoxycortisol, 11-deoxycorticosterone, and 17-OH-progesterone) was chosen. The integration of the Isotope Inversion Experiment in the validation protocol for the steroid assay was successfully realized. The accuracy results of the inverse quality controls were all in all very satisfying. As a consequence the suitability of a surrogate matrix calibration for quantification of the targeted steroids in human serum as authentic matrix could be successfully demonstrated. The Isotope Inversion Experiment fills a gap in the validation process for LC-MS/MS assays

  3. Permutation criteria to evaluate multiple clinical endpoints in a proof-of-concept study : lessons from Pre-RELAX-AHF

    NARCIS (Netherlands)

    Davison, Beth A.; Cotter, Gad; Sun, Hengrui; Chen, Li; Teerlink, John R.; Metra, Marco; Felker, G. Michael; Voors, Adriaan A.; Ponikowski, Piotr; Filippatos, Gerasimos; Greenberg, Barry; Teichman, Sam L.; Unemori, Elaine; Koch, Gary G.

    2011-01-01

    Clinically relevant endpoints cannot be routinely targeted with reasonable power in a small study. Hence, proof-of-concept studies are often powered to a primary surrogate endpoint. However, in acute heart failure (AHF) effects on surrogates have not translated into clinical benefit in confirmatory

  4. Fast Prediction and Evaluation of Gravitational Waveforms Using Surrogate Models

    Directory of Open Access Journals (Sweden)

    Scott E. Field

    2014-07-01

    Full Text Available We propose a solution to the problem of quickly and accurately predicting gravitational waveforms within any given physical model. The method is relevant for both real-time applications and more traditional scenarios where the generation of waveforms using standard methods can be prohibitively expensive. Our approach is based on three offline steps resulting in an accurate reduced order model in both parameter and physical dimensions that can be used as a surrogate for the true or fiducial waveform family. First, a set of m parameter values is determined using a greedy algorithm from which a reduced basis representation is constructed. Second, these m parameters induce the selection of m time values for interpolating a waveform time series using an empirical interpolant that is built for the fiducial waveform family. Third, a fit in the parameter dimension is performed for the waveform’s value at each of these m times. The cost of predicting L waveform time samples for a generic parameter choice is of order O(mL+mc_{fit} online operations, where c_{fit} denotes the fitting function operation count and, typically, m≪L. The result is a compact, computationally efficient, and accurate surrogate model that retains the original physics of the fiducial waveform family while also being fast to evaluate. We generate accurate surrogate models for effective-one-body waveforms of nonspinning binary black hole coalescences with durations as long as 10^{5}M, mass ratios from 1 to 10, and for multiple spherical harmonic modes. We find that these surrogates are more than 3 orders of magnitude faster to evaluate as compared to the cost of generating effective-one-body waveforms in standard ways. Surrogate model building for other waveform families and models follows the same steps and has the same low computational online scaling cost. For expensive numerical simulations of binary black hole coalescences, we thus anticipate extremely large speedups in

  5. Optimization using surrogate models - by the space mapping technique

    DEFF Research Database (Denmark)

    Søndergaard, Jacob

    2003-01-01

    mapping surrogate has a lower approximation error for long steps. For short steps, however, the Taylor model of the expensive model is best, due to exact interpolation at the model origin. Five algorithms for space mapping optimization are presented and the numerical performance is evaluated. Three...... conditions are satisfied. So hybrid methods, combining the space mapping technique with classical optimization methods, should be used if convergence to high accuracy is wanted. Approximation abilities of the space mapping surrogate are compared with those of a Taylor model of the expensive model. The space...

  6. Optimization using surrogate models - by the space mapping technique

    DEFF Research Database (Denmark)

    Søndergaard, Jacob

    2003-01-01

    mapping surrogate has a lower approximation error for long steps. For short steps, however, the Taylor model of the expensive model is best, due to exact interpolation at the model origin. Five algorithms for space mapping optimization are presented and the numerical performance is evaluated. Three...... conditions are satisfied. So hybrid methods, combining the space mapping technique with classical optimization methods, should be used if convergence to high accuracy is wanted. Approximation abilities of the space mapping surrogate are compared with those of a Taylor model of the expensive model. The space...

  7. Characterization of Non-Infectious Virus-Like Particle Surrogates for Viral Clearance Applications.

    Science.gov (United States)

    Johnson, Sarah; Brorson, Kurt A; Frey, Douglas D; Dhar, Arun K; Cetlin, David A

    2017-03-09

    Viral clearance is a critical aspect of biopharmaceutical manufacturing process validation. To determine the viral clearance efficacy of downstream chromatography and filtration steps, live viral "spiking" studies are conducted with model mammalian viruses such as minute virus of mice (MVM). However, due to biosafety considerations, spiking studies are costly and typically conducted in specialized facilities. In this work, we introduce the concept of utilizing a non-infectious MVM virus-like particle (MVM-VLP) as an economical surrogate for live MVM during process development and characterization. Through transmission electron microscopy, size exclusion chromatography with multi-angle light scattering, chromatofocusing, and a novel solute surface hydrophobicity assay, we examined and compared the size, surface charge, and hydrophobic properties of MVM and MVM-VLP. The results revealed that MVM and MVM-VLP exhibited nearly identical physicochemical properties, indicating the potential utility of MVM-VLP as an accurate and economical surrogate to live MVM during chromatography and filtration process development and characterization studies.

  8. Imaging readouts as biomarkers or surrogate parameters for the assessment of therapeutic interventions

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, Markus [University of Zuerich/ETH Zuerich, Institute for Biomedical Engineering, Zuerich (Switzerland); University of Zuerich, Institute for Pharmacology and Toxicology, Zuerich (Switzerland)

    2007-10-15

    Surrogate markers and biomarkers based on imaging readouts providing predictive information on clinical outcome are of increasing importance in the preclinical and clinical evaluation of novel therapies. They are primarily used in studies designed to establish evidence that the therapeutic principle is valid in a representative patient population or in an individual. A critical step in the development of (imaging) surrogates is validation: correlation with established clinical endpoints must be demonstrated. Biomarkers must not fulfill such stringent validation criteria; however, they should provide insight into mechanistic aspects of the therapeutic intervention (proof-of-mechanism) or document therapy efficacy with prognostic quality with regard to the long-term clinical outcome (proof of concept). Currently used imaging biomarkers provide structural, physiological and metabolic information. Novel imaging approaches annotate structure with molecular signatures that are tightly linked to the pathophysiology or to the therapeutic principle. These cellular and molecular imaging methods yield information on drug biodistribution, receptor expression and occupancy, and/or intra- and intercellular signaling. The design of novel target-specific imaging probes is closely related to the development of the therapeutic agents and should be considered early in the discovery phase. Significant technical and regulatory hurdles have to be overcome to foster the use of imaging biomarkers for clinical drug evaluation. (orig.)

  9. Summary of Remediated Nitrate Salt Surrogate Formulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Geoffrey Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Leonard, Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hartline, Ernest Leon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tian, Hongzhao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-05

    High Explosives Science and Technology (M-7) completed all required formulation and testing of Remediated Nitrate Salt (RNS) surrogates on April 27, 2016 as specified in PLAN-TA9-2443 Rev B, "Remediated Nitrate Salt (RNS) Surrogate Formulation and Testing Standard Procedure", released February 16, 2016. This report summarizes the results of the work and also includes additional documentation required in that test plan. All formulation and testing was carried out according to PLAN-TA9-2443 Rev B. The work was carried out in three rounds, with the full matrix of samples formulated and tested in each round. Results from the first round of formulation and testing were documented in memorandum M7-J6-6042, " Results from First Round of Remediated Nitrate Salt Surrogate Formulation and Testing." Results from the second round of formulation and testing were documented in M7-16-6053 , "Results from the Second Round of Remediated Nitrate Salt Surrogate Formulation and Testing." Initial results from the third round were documented in M7-16-6057, "Initial Results from the Third Round of Remediated Nitrate Salt Formulation and Testing."

  10. Frequency response as a surrogate eigenvalue problem in topology optimization

    DEFF Research Database (Denmark)

    Andreassen, Erik; Ferrari, Federico; Sigmund, Ole

    2017-01-01

    This article discusses the use of frequency response surrogates for eigenvalue optimization problems in topology optimization that may be used to avoid solving the eigenvalue problem. The motivation is to avoid complications that arise from multiple eigenvalues and the computational complexity as...

  11. GENERATING SOPHISTICATED SPATIAL SURROGATES USING THE MIMS SPATIAL ALLOCATOR

    Science.gov (United States)

    The Multimedia Integrated Modeling System (MIMS) Spatial Allocator is open-source software for generating spatial surrogates for emissions modeling, changing the map projection of Shapefiles, and performing other types of spatial allocation that does not require the use of a comm...

  12. Strength Reliability Analysis of Turbine Blade Using Surrogate Models

    Directory of Open Access Journals (Sweden)

    Wei Duan

    2014-05-01

    Full Text Available There are many stochastic parameters that have an effect on the reliability of steam turbine blades performance in practical operation. In order to improve the reliability of blade design, it is necessary to take these stochastic parameters into account. In this study, a variable cross-section twisted blade is investigated and geometrical parameters, material parameters and load parameters are considered as random variables. A reliability analysis method as a combination of a Finite Element Method (FEM, a surrogate model and Monte Carlo Simulation (MCS, is applied to solve the blade reliability analysis. Based on the blade finite element parametrical model and the experimental design, two kinds of surrogate models, Polynomial Response Surface (PRS and Artificial Neural Network (ANN, are applied to construct the approximation analytical expressions between the blade responses (including maximum stress and deflection and random input variables, which act as a surrogate of finite element solver to drastically reduce the number of simulations required. Then the surrogate is used for most of the samples needed in the Monte Carlo method and the statistical parameters and cumulative distribution functions of the maximum stress and deflection are obtained by Monte Carlo simulation. Finally, the probabilistic sensitivities analysis, which combines the magnitude of the gradient and the width of the scatter range of the random input variables, is applied to evaluate how much the maximum stress and deflection of the blade are influenced by the random nature of input parameters.

  13. Recent Progress in the Development of Diesel Surrogate Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J

    2009-09-04

    There has been much recent progress in the area of surrogate fuels for diesel. In the last few years, experiments and modeling have been performed on higher molecular weight components of relevance to diesel fuel such as n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). Chemical kinetic models have been developed for all the n-alkanes up to 16 carbon atoms. Also, there has been much experimental and modeling work on lower molecular weight surrogate components such as n-decane and do-decane which are most relevant to jet fuel surrogates, but are also relevant to diesel surrogates where simulation of the full boiling point range is desired. For the cycloalkanes, experimental work on decalin and tetralin recently has been published. For multi-component surrogate fuel mixtures, recent work on modeling of these mixtures and comparisons to real diesel fuel is reviewed. Detailed chemical kinetic models for surrogate fuels are very large in size. Significant progress also has been made in improving the mechanism reduction tools that are needed to make these large models practicable in multidimensional reacting flow simulations of diesel combustion. Nevertheless, major research gaps remain. In the case of iso-alkanes, there are experiments and modeling work on only one of relevance to diesel: iso-cetane. Also, the iso-alkanes in diesel are lightly branched and no detailed chemical kinetic models or experimental investigations are available for such compounds. More components are needed to fill out the iso-alkane boiling point range. For the aromatic class of compounds, there has been no new work for compounds in the boiling point range of diesel. Most of the new work has been on alkyl aromatics that are of the range C7 to C8, below the C10 to C20 range that is needed. For the chemical class of cycloalkanes, experiments and modeling on higher molecular weight components are warranted. Finally for multi-component surrogates needed to treat real diesel

  14. Recent Progress in the Development of Diesel Surrogate Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Mueller, C J

    2009-12-09

    There has been much recent progress in the area of surrogate fuels for diesel. In the last few years, experiments and modeling have been performed on higher molecular weight components of relevance to diesel fuel such as n-hexadecane (n-cetane) and 2,2,4,4,6,8,8-heptamethylnonane (iso-cetane). Chemical kinetic models have been developed for all the n-alkanes up to 16 carbon atoms. Also, there has been much experimental and modeling work on lower molecular weight surrogate components such as n-decane and n-dodecane that are most relevant to jet fuel surrogates, but are also relevant to diesel surrogates where simulation of the full boiling point range is desired. For two-ring compounds, experimental work on decalin and tetralin recently has been published. For multi-component surrogate fuel mixtures, recent work on modeling of these mixtures and comparisons to real diesel fuel is reviewed. Detailed chemical kinetic models for surrogate fuels are very large in size. Significant progress also has been made in improving the mechanism reduction tools that are needed to make these large models practicable in multi-dimensional reacting flow simulations of diesel combustion. Nevertheless, major research gaps remain. In the case of iso-alkanes, there are experiments and modeling work on only one of relevance to diesel: iso-cetane. Also, the iso-alkanes in diesel are lightly branched and no detailed chemical kinetic models or experimental investigations are available for such compounds. More components are needed to fill out the iso-alkane boiling point range. For the aromatic class of compounds, there has been no new work for compounds in the boiling point range of diesel. Most of the new work has been on alkyl aromatics that are of the range C7 to C8, below the C10 to C20 range that is needed. For the chemical class of cycloalkanes, experiments and modeling on higher molecular weight components are warranted. Finally for multi-component surrogates needed to treat real

  15. Development of a Human Cranial Bone Surrogate for Impact Studies.

    Science.gov (United States)

    Roberts, Jack C; Merkle, Andrew C; Carneal, Catherine M; Voo, Liming M; Johannes, Matthew S; Paulson, Jeff M; Tankard, Sara; Uy, O Manny

    2013-01-01

    In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the three-layer (inner table-diplöe-outer table) architecture of the human skull. The materials selected to represent the surrogate cranial tables consisted of two different epoxy resins systems with random milled glass fiber to enhance the strength and stiffness and the materials to represent the surrogate diplöe consisted of three low density foams. Forty-one three-point bending fracture toughness tests were performed on nine material combinations. The materials that best represented the fracture toughness of cranial tables were then selected and formed into tensile samples and tested. These materials were then used with the two surrogate diplöe foam materials to create the three-layer surrogate cranial bone samples for three-point bending tests. Drop tower tests were performed on flat samples created from these materials and the fracture patterns were very similar to the linear fractures in pendulum impacts of intact human skulls, previously reported in the literature. The surrogate cranial tables had the quasi-static fracture toughness and tensile strength of 2.5 MPa√ m and 53 ± 4.9 MPa, respectively, while the same properties of human compact bone were 3.1 ± 1.8 MPa√ m and 68 ± 18 MPa, respectively. The cranial surrogate had a quasi-static bending strength of 68 ± 5.7 MPa, while that of cranial bone was 82 ± 26 MPa. This material/design is currently being used to construct spherical shell samples for drop tower and ballistic tests.

  16. Longing: a concept analysis.

    Science.gov (United States)

    Pehler, Shelley-Rae; Sjostrom, Stephanie; Markwardt, Michelle

    2014-10-01

    This paper uses Rodgers' evolutionary view of concept analysis to define the human response of longing. The purpose is to develop a definition of longing as the first step in diagnosis development. A literature review was conducted by searching the Cumulative Index to Nursing and Allied Health Literature, American Theological Library Association Religion, JSTOR Philosophy, JSTOR Religion, PsycINFO, and PubMed databases to yield an across-discipline sample of articles. Three researchers identified the attributes, antecedents, consequences, situational context, and surrogate terms of longing. An operational definition was developed. Longing is clearly a human response to loss, crossing illness and situations in which nurses encounter patients in multiple settings. This supports the need to further develop longing into a nursing diagnosis. © 2014 NANDA International.

  17. The genetic truth of surrogate parentage.

    Science.gov (United States)

    Goswami, Gajendra K

    2015-12-01

    Old family laws presume that the husband is the father of any child born to a married couple; a socio-legal fiction. A social and biological father is presumed to be one and the same. The cocoon of legitimacy protects marriage but the child born outside valid marriage is recognised as 'illegitimate'. Assisted reproduction technologies strengthened reproductive rights but confuse purity of lineage and genetically divorce socio-legal parentage from biological parentage. The lesbian, gay, bisexual, and transgender reproductive rights, surrogacy, gamete donation, delayed pregnancies using cryopreserved embryos, single parentage, virgin mothers (virgin birth), live-in relationship are increasingly recognised under the cover of human dignity but obscure parentage. In contrast to parental rights of reproductive autonomy, equity demands the child's right to know its biological parentage, recognised under Article 7 of the UN Convention on the Rights of the Child, 1989. DNA profiling may clarify the genetic parentage with virtual certainty but with multiple limitations. DNA forensics ascertains the genetic makeup of a child linking putative parents irrespective of any social relationship between them. The right to know biological linkages gained paramount significance in cases like displacement, adoption, child trafficking and variants of cross-genetic in vitro fertilization including complete surrogacy. The 'reproductive tourism' promotes crossing borders and bodies, enabling conception in the countries with extreme religious and legal barriers. © The Author(s) 2015.

  18. Hall et al., 2016 Artificial Turf Surrogate Surface Methods Paper Data File

    Data.gov (United States)

    U.S. Environmental Protection Agency — Mercury dry deposition data quantified via static water surrogate surface (SWSS) and artificial turf surrogate surface (ATSS) collectors. This dataset is associated...

  19. Determining high-quality critical body residues for multiple species and chemicals by applying improved experimental design and data interpretation concepts

    NARCIS (Netherlands)

    van der Heijden, Stephan A; Hermens, Joop L M; Sinnige, Theo L; Mayer, Philipp; Gilbert, Dorothea; Jonker, Michiel T O

    2015-01-01

    Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept provid

  20. Determining high-quality critical body residues for multiple species and chemicals by applying improved experimental design and data interpretation concepts

    NARCIS (Netherlands)

    van der Heijden, Stephan A; Hermens, Joop L M; Sinnige, Theo L; Mayer, Philipp; Gilbert, Dorothea; Jonker, Michiel T O

    2015-01-01

    Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept

  1. [Regulation of surrogate gestation and maternity in the state of Tabasco].

    Science.gov (United States)

    Ortiz, Miguel Ángel León

    2015-01-01

    In recent years, one of the most disconcerting issues in bioethics, a field closely related to legal disciplines, is surrogate gestation or surrogacy. Very little is known about the medical nature of these novel therapeutic processes in legal study. Different dilemmas emerge in the fields of ethics, medicine and law. This paper analyses the normative content of the Tabasco civil regime with respect to the concepts, types and effects of surrogacy. It emphasizes the primacy of protecting the physical and emotional integrity of pregnant women and the legal protection of the nasciturus. In addition, this paper shows the exceptional nature of this prerogative for infertile people who cannot get pregnant through any other medical means, by posing surrogacy's ultima ratio regum characteristics.

  2. [The Best Interest of the Child in the Case of Surrogate Maternity].

    Science.gov (United States)

    Garibo Peyró, Ana-Paz

    2017-01-01

    This article claims to analyze the situation of children born by means of surrogate maternity contract since these babies are one of the most vulnerable parts of this agreement, so their rights and interests could be affected in many ways. In order to study that situation, in the first place, has been accomplished a brief analysis of the concept of the best interest of the child. Afterwards it is examined the possible violation of the best interest of the child in the cases that have already been examined by Doctrine and Jurisprudence, that is, first the case of registration of these children in the country of origin Civil Registry of the intentional parents, and, in second place, the case of maternity benefit for intentional mothers. The article concludes with a reflection about other situations in where the best interest of children can be affected , such as their right to know their biological origins or the cases of identity problems.

  3. Concept Maps

    OpenAIRE

    Schwendimann, Beat Adrian

    2014-01-01

    A concept map is a node-link diagram showing the semantic relationships among concepts. The technique for constructing concept maps is called "concept mapping". A concept map consists of nodes, arrows as linking lines, and linking phrases that describe the relationship between nodes. Two nodes connected with a labeled arrow are called a proposition. Concept maps are versatile graphic organizers that can represent many different forms of relationships between concepts. The relationship between...

  4. Sequential optimization of strip bending process using multiquadric radial basis function surrogate models

    NARCIS (Netherlands)

    Havinga, Gosse Tjipke; van den Boogaard, Antonius H.; Klaseboer, G.

    2013-01-01

    Surrogate models are used within the sequential optimization strategy for forming processes. A sequential improvement (SI) scheme is used to refine the surrogate model in the optimal region. One of the popular surrogate modeling methods for SI is Kriging. However, the global response of Kriging mode

  5. Assessing sloth bears as surrogates for carnivore conservation in Sri Lanka

    Science.gov (United States)

    Ratnayeke, Shyamala; Van Manen, Frank T.

    2012-01-01

    Bears are large, charismatic mammals whose presence often garners conservation attention. Because healthy bear populations typically require large, contiguous areas of habitat, land conservation actions often are assumed to benefit co-occurring species, including other mammalian carnivores. However, we are not aware of an empirical test of this assumption. We used remote camera data from 2 national parks in Sri Lanka to test the hypothesis that the frequency of detection of sloth bears (Melursus ursinus) is associated with greater richness of carnivore species. We focused on mammalian carnivores because they play a pivotal role in the stability of ecological communities and are among Sri Lanka's most endangered species. Seven of Sri Lanka's carnivores are listed as endangered, vulnerable, or near threatened, and little empirical information exists on their status and distribution. During 2002–03, we placed camera traps at 152 sites to document carnivore species presence. We used Poisson regression to develop predictive models for 3 categories of dependent variables: species richness of (1) all carnivores, (2) carnivores considered at risk, and (3) carnivores of least conservation concern. For each category, we analyzed 8 a priori models based on combinations of sloth bear detections, sample year, and study area and used Akaike's information criterion (AICc) to test our research hypothesis. We detected sloth bears at 55 camera sites and detected 13 of Sri Lanka's 14 Carnivora species. Species richness of all carnivores showed positive associations with the number of sloth bear detections, regardless of study area. Sloth bear detections were also positively associated with species richness of carnivores at risk across both study years and study areas, but not with species richness of common carnivores. Sloth bears may serve as a valuable surrogate species whose habitat protection would contribute to conservation of other carnivores in Sri Lanka.

  6. Compound-nuclear reaction cross sections via the Surrogate method: considering the underlying assumptions

    Science.gov (United States)

    Escher, Jutta; Dietrich, Frank

    2006-10-01

    The Surrogate Nuclear Reactions approach makes it possible to determine compound-nuclear reaction cross sections indirectly. The method has been employed to determine (n,f) cross sections for various actinides, including unstable species [1-4]; other, primarily neutron- induced, reactions are being considered also [5,6]. The extraction of the sought-after cross sections typically relies on approximations to the full Surrogate formalism [7]. This presentation will identify and critically examine the most significant assumptions underlying the experimental work carried out so far. Calculations that test the validity of the approximations employed will be presented. [1] J.D. Cramer and H.C. Britt, Nucl. Sci. and Eng. 41, 177(1970); H.C. Britt and J.B. Wilhelmy, ibid. 72, 222(1979) [2] M. Petit et al, Nucl. Phys. A735, 345(2004) [3] C. Plettner et al, Phys. Rev. C 71, 051602(2005); J. Burke et al, Phys. Rev. C. 73, 054604(2006) [4] W. Younes and H.C. Britt, Phys. Rev. C 67, 024610(2003); 68, 034610(2003) [5] L.A. Bernstein et al, AIP Conf. Proc. 769, 890(2005) [6] J. Escher et al, Nucl. Phys. A758, 43c(2005) [7] J. Escher and F.S. Dietrich, submitted (2006)

  7. Modeling of NO sensitization of IC engines surrogate fuels auto-ignition and combustion

    CERN Document Server

    Anderlohr, Jörg; Bounaceur, Roda; Battin-Leclerc, Frédérique

    2009-01-01

    This paper presents a new chemical kinetic model developed for the simulation of auto-ignition and combustion of engine surrogate fuel mixtures sensitized by the presence of NOx. The chemical mechanism is based on the PRF auto-ignition model (n-heptane/iso-octane) of Buda et al. [1] and the NO/n-butane/n-pentane model of Glaude et al. [2]. The later mechanism has been taken as a reference for the reactions of NOx with larger alcanes (n-heptane, iso-octane). A coherent two components engine fuel surrogate mechanism has been generated which accounts for the influence of NOx on auto-ignition. The mechanism has been validated for temperatures between 700 K and 1100 K and pressures between 1 and 10 atm covering the temperature and pressure ranges characteristic of engine post-oxidation thermodynamic conditions. Experiments used for validation include jet stirred reactor conditions for species evolution as a function of temperature, as well as diesel HCCI engine experiments for auto-ignition delay time measurements...

  8. The species concept in a marine diatom: LSU rDNA–based phylogenetic differentiation in Skeletonema marinoi/dohrnii (Bacillariophyceae) is not reflected in morphology

    DEFF Research Database (Denmark)

    Ellegaard, Marianne; Godhe, Anna; Härnström, Karolina;

    2008-01-01

    The ubiquitous marine diatom genus Skeletonema includes several newly described species. This paper presents a study of morphology and LSU sequence diversity of one of these new species, Skeletonema marinoi. The 15 monoclonal strains (from the Swedish west coast, the Swedish east coast, Portugal...... dohrnii. In the original description of these two species, they were differentiated by the structure of the girdle bands. However, the girdle band types of both species were found within single samples of almost all clones of S. marinoi in this study. The LSU-based phylogeny is consistent with the split...... and Canada) included in the study showed differences in LSU rDNA sequence within the morphospecies, with differences seen even among clones established from a single plankton net sample. Morphologically, all clones were indistinguishable from each other and from the closely related species Skeletonema...

  9. DNA-Based Taxonomy in Ecologically Versatile Microalgae: A Re-Evaluation of the Species Concept within the Coccoid Green Algal Genus Coccomyxa (Trebouxiophyceae, Chlorophyta).

    Science.gov (United States)

    Malavasi, Veronica; Škaloud, Pavel; Rindi, Fabio; Tempesta, Sabrina; Paoletti, Michela; Pasqualetti, Marcella

    2016-01-01

    Coccomyxa is a genus of unicellular green algae of the class Trebouxiophyceae, well known for its cosmopolitan distribution and great ecological amplitude. The taxonomy of this genus has long been problematic, due to reliance on badly-defined and environmentally variable morphological characters. In this study, based on the discovery of a new species from an extreme habitat, we reassess species circumscription in Coccomyxa, a unicellular genus of the class Trebouxiophyceae, using a combination of ecological and DNA sequence data (analyzed with three different methods of algorithmic species delineation). Our results are compared with those of a recent integrative study of Darienko and colleagues that reassessed the taxonomy of Coccomyxa, recognizing 7 species in the genus. Expanding the dataset from 43 to 61 sequences (SSU + ITS rDNA) resulted in a different delimitation, supporting the recognition of a higher number of species (24 to 27 depending on the analysis used, with the 27-species scenario receiving the strongest support). Among these, C. melkonianii sp. nov. is described from material isolated from a river highly polluted by heavy metals (Rio Irvi, Sardinia, Italy). Analyses performed on ecological characters detected a significant phylogenetic signal in six different characters. We conclude that the 27-species scenario is presently the most realistic for Coccomyxa and we suggest that well-supported lineages distinguishable by ecological preferences should be recognized as different species in this genus. We also recommend that for microbial lineages in which the overall diversity is unknown and taxon sampling is sparse, as is often the case for green microalgae, the results of analyses for algorithmic DNA-based species delimitation should be interpreted with extreme caution.

  10. A Parallel and Distributed Surrogate Model Implementation for Computational Steering

    KAUST Repository

    Butnaru, Daniel

    2012-06-01

    Understanding the influence of multiple parameters in a complex simulation setting is a difficult task. In the ideal case, the scientist can freely steer such a simulation and is immediately presented with the results for a certain configuration of the input parameters. Such an exploration process is however not possible if the simulation is computationally too expensive. For these cases we present in this paper a scalable computational steering approach utilizing a fast surrogate model as substitute for the time-consuming simulation. The surrogate model we propose is based on the sparse grid technique, and we identify the main computational tasks associated with its evaluation and its extension. We further show how distributed data management combined with the specific use of accelerators allows us to approximate and deliver simulation results to a high-resolution visualization system in real-time. This significantly enhances the steering workflow and facilitates the interactive exploration of large datasets. © 2012 IEEE.

  11. The Theory and Practice of Surrogate Decision-Making.

    Science.gov (United States)

    Wendler, David

    2017-01-01

    When a patient lacks decision-making capacity and has not left a clear advance directive, there is now widespread agreement that patient-designated and next-of-kin surrogates should implement substituted judgment within a process of shared decision-making. Specifically, after discussing the "best scientific evidence available, as well as the patient's values, goals, and preferences" with the patient's clinicians, the patient-designated or next-of-kin surrogate should attempt to determine what decision the patient would have made in the circumstances. To the extent that this approach works, it seems to provide about as much respect for the autonomy of incapacitated patients as we could ask for. But, as articles in this issue of the Report by Jeffrey Berger and by Ellen Robinson and colleagues emphasize, reality presents challenges. © 2017 The Hastings Center.

  12. Resilient ageing: a concept analysis.

    Science.gov (United States)

    Hicks, Maxine M; Conner, Norma E

    2014-04-01

    This paper is a report of an analysis of the concept resilient ageing. Unique in comparison with other healthy ageing concepts, resilient ageing can be applied to all older people, regardless of age or affliction. The state of global population expansion in older people over the next 50 years calls for increased health promotion research efforts to ensure the maintenance of health and optimal quality of life for all older people. Literature for this concept analysis was retrieved from several databases, CINAHL, PubMed PsycINFO, for the years 1990-2012. Rodgers's evolutionary method of concept analysis was used because of its applicability to concepts that are still evolving. An integrative research review methodology was applied to peer-reviewed journal articles (n = 46) for an inductive analysis of the concept of resilient ageing. The antecedents, defining attributes, and consequence of resilient ageing were identified. Antecedents to resilient ageing were found to be adversity and protective factors, while the core attributes include coping, hardiness and self-concept. The consequence of the process of resilient ageing was optimal quality of life. Sense of coherence was found to be the surrogate term. The results obtained were further substantiated using Antonovsky's (1979) theory of salutogenesis. A theoretical definition and a model of resilient ageing were developed. In addition, a discussion was provided on the practice, policy and research implications for promoting the development of protective factors and resilient ageing. © 2013 John Wiley & Sons Ltd.

  13. Commercial agencies and surrogate motherhood: a transaction cost approach.

    Science.gov (United States)

    Galbraith, Mhairi; McLachlan, Hugh V; Swales, J Kim

    2005-03-01

    In this paper we investigate the legal arrangements involved in UK surrogate motherhood from a transaction-cost perspective. We outline the specific forms the transaction costs take and critically comment on the way in which the UK institutional and organisational arrangements at present adversely influence transaction costs. We then focus specifically on the potential role of surrogacy agencies and look at UK and US evidence on commercial and voluntary agencies. Policy implications follow.

  14. Quantification of the Relationship between Surrogate Fuel Structure and Performance

    Science.gov (United States)

    2012-07-31

    cycloperoxy-5-yl (BICYC5.O2) and bicyclo[2,2,1]hexene peroxy (C2O2H221) radicals . The latter route leads to the formation of vinyl ketene and the formyl ...3089 selection of stable molecule and radicals . The adopted calculation method for the determination of such data is outlined in Appendix 1...chemistry of aromatic fuel components used in surrogate fuels and the importance of the cyclopentadi- enyl radical in poly-aromatic hydrocarbon (PAH

  15. Regression calibration with more surrogates than mismeasured variables

    KAUST Repository

    Kipnis, Victor

    2012-06-29

    In a recent paper (Weller EA, Milton DK, Eisen EA, Spiegelman D. Regression calibration for logistic regression with multiple surrogates for one exposure. Journal of Statistical Planning and Inference 2007; 137: 449-461), the authors discussed fitting logistic regression models when a scalar main explanatory variable is measured with error by several surrogates, that is, a situation with more surrogates than variables measured with error. They compared two methods of adjusting for measurement error using a regression calibration approximate model as if it were exact. One is the standard regression calibration approach consisting of substituting an estimated conditional expectation of the true covariate given observed data in the logistic regression. The other is a novel two-stage approach when the logistic regression is fitted to multiple surrogates, and then a linear combination of estimated slopes is formed as the estimate of interest. Applying estimated asymptotic variances for both methods in a single data set with some sensitivity analysis, the authors asserted superiority of their two-stage approach. We investigate this claim in some detail. A troubling aspect of the proposed two-stage method is that, unlike standard regression calibration and a natural form of maximum likelihood, the resulting estimates are not invariant to reparameterization of nuisance parameters in the model. We show, however, that, under the regression calibration approximation, the two-stage method is asymptotically equivalent to a maximum likelihood formulation, and is therefore in theory superior to standard regression calibration. However, our extensive finite-sample simulations in the practically important parameter space where the regression calibration model provides a good approximation failed to uncover such superiority of the two-stage method. We also discuss extensions to different data structures.

  16. Diaphragm as an anatomic surrogate for lung tumor motion

    CERN Document Server

    Cervino, Laura I; Sandhu, Ajay; Jiang, Steve B

    2009-01-01

    Lung tumor motion due to respiration poses a challenge in the application of modern three-dimensional conformal radiotherapy. Direct tracking of the lung tumor during radiation therapy is very difficult without implanted fiducial markers. Indirect tracking relies on the correlation of the tumor's motion and the surrogate's motion. The present paper presents an analysis of the correlation between the tumor motion and the diaphragm motion in order to evaluate the potential use of diaphragm as a surrogate for tumor motion. We have analyzed the correlation between diaphragm motion and superior-inferior lung tumor motion in 32 fluoroscopic image sequences from 10 lung cancer patients. A simple linear model and a more complex linear model that accounts for phase delays between the two motions have been used. Results show that the diaphragm is a good surrogate for tumor motion prediction for most patients, resulting in an average correlation factor of 0.94 and 0.98 with each model respectively. The model that accoun...

  17. Evaluation of bone surrogates for indirect and direct ballistic fractures.

    Science.gov (United States)

    Bir, Cynthia; Andrecovich, Chris; DeMaio, Marlene; Dougherty, Paul J

    2016-04-01

    The mechanism of injury for fractures to long bones has been studied for both direct ballistic loading as well as indirect. However, the majority of these studies have been conducted on both post-mortem human subjects (PMHS) and animal surrogates which have constraints in terms of storage, preparation and testing. The identification of a validated bone surrogate for use in forensic, medical and engineering testing would provide the ability to investigate ballistic loading without these constraints. Two specific bone surrogates, Sawbones and Synbone, were evaluated in comparison to PMHS for both direct and indirect ballistic loading. For the direct loading, the mean velocity to produce fracture was 121 ± 19 m/s for the PMHS, which was statistically different from the Sawbones (140 ± 7 m/s) and Synbone (146 ± 3 m/s). The average distance to fracture in the indirect loading was .70 cm for the PMHS. The Synbone had a statistically similar average distance to fracture (.61 cm, p=0.54) however the Sawbones average distance to fracture was statistically different (.41 cm, pballistic testing was not identified and future work is warranted.

  18. Surrogate Assisted Design Optimization of an Air Turbine

    Directory of Open Access Journals (Sweden)

    Rameez Badhurshah

    2014-01-01

    Full Text Available Surrogates are cheaper to evaluate and assist in designing systems with lesser time. On the other hand, the surrogates are problem dependent and they need evaluation for each problem to find a suitable surrogate. The Kriging variants such as ordinary, universal, and blind along with commonly used response surface approximation (RSA model were used in the present problem, to optimize the performance of an air impulse turbine used for ocean wave energy harvesting by CFD analysis. A three-level full factorial design was employed to find sample points in the design space for two design variables. A Reynolds-averaged Navier Stokes solver was used to evaluate the objective function responses, and these responses along with the design variables were used to construct the Kriging variants and RSA functions. A hybrid genetic algorithm was used to find the optimal point in the design space. It was found that the best optimal design was produced by the universal Kriging while the blind Kriging produced the worst. The present approach is suggested for renewable energy application.

  19. A comparative study of the oxidation characteristics of two gasoline fuels and an n-heptane/iso-octane surrogate mixture

    KAUST Repository

    Javed, Tamour

    2015-01-01

    Ignition delay times and CO, H2O, OH and CO2 time-histories were measured behind reflected shock waves for two FACE (Fuels for Advanced Combustion Engines) gasolines and one PRF (Primary Reference Fuel) blend. The FACE gasolines chosen for this work are primarily paraffinic and have the same octane rating (∼RON = 84) as the PRF blend, but contain varying amounts of iso- and n-paraffins. Species time-histories and ignition delay times were measured using laser absorption methods over a temperature range of 1350-1550 K and pressures near 2 atm. Measured species time-histories and ignition delay times of the PRF blend and the two FACE fuels agreed reasonably well. However, when compared to recent gasoline surrogate mechanisms, the simulations did not capture some of the kinetic trends found in the species profiles. To our knowledge, this work provides some of the first shock tube species time-history data for gasoline fuels and PRF surrogates and should enable further improvements in detailed kinetic mechanisms of gasoline fuels.

  20. Sociocultural Variables That Impact High School Students' Perceptions of Native Fauna: a Study on the Species Component of the Biodiversity Concept

    Science.gov (United States)

    Bermudez, Gonzalo M. A.; Battistón, Luisina V.; García Capocasa, María C.; De Longhi, Ana L.

    2017-02-01

    This study investigates the influence of school sector (private versus state schools) and student gender on knowledge of native fauna. Our main objectives were (a) to describe the knowledge of high school students from the province of Cordoba, Argentina with respect to native animal species, (b) to determine if any exotic species (introduced or domestic) are considered native, and (c) to analyze the effects of school sector and gender on the students' knowledge of the native fauna. In total, 321 students aged 15-18 from 14 urban schools (8 state and 6 private schools) were asked to write down ten animals native to Córdoba, Argentina, in a free-list questionnaire. Relative frequencies and Generalized Linear Mixed Models (GLMM) were used to analyze the categorized (animal names) and continuous answers (quantity of responses, number of native animals, etc.), with the 25 most frequently mentioned species showing a predominance of native ones, of which "Puma" ( Puma concolor) and "Andean condor" ( Vultur gryphus) were the most prominent. An overrepresentation of mammalian species compared to other classes of chordates was also found, with high school students mentioning native and domestic species higher on the free-list. Using GLMM, we found that school sector had a significant effect on the number of native animals mentioned at both national and local levels, and on domestic and mixed species. Finally, male students mentioned more species and more native animals than their female counterparts. These findings were interpreted and discussed in light of sociocultural and traditional ecological knowledge theories, from which several implications arose related to research and practice.

  1. Efficacy of novel phenoxyalkyl pyridinium oximes as brain-penetrating reactivators of cholinesterase inhibited by surrogates of sarin and VX.

    Science.gov (United States)

    Chambers, Janice E; Chambers, Howard W; Funck, Kristen E; Meek, Edward C; Pringle, Ronald B; Ross, Matthew K

    2016-11-25

    Pyridinium oximes are strong nucleophiles and many are effective reactivators of organophosphate-inhibited cholinesterase (ChE). However, the current oxime reactivators are ineffective at crossing the blood-brain barrier and reactivating brain ChE in the intact organism. Our laboratories have developed a series of substituted phenoxyalkyl pyridinium oximes (US patent 9,227,937 B2) with the goal of identifying reactivators effective in crossing the blood-brain barrier. The first 35 of the series were found to have similar in vitro efficacy as reactivators of ChE inhibited by a sarin surrogate (phthalimidyl isopropyl methylphosphonate, PIMP) or a VX surrogate (nitrophenyl ethyl methylphosphonate, NEMP) in bovine brain preparations as previously observed in rat brain preparations. A number of these novel oximes have shown the ability to decrease the level of ChE inhibition in the brains of rats treated with a high sublethal dosage of either a sarin surrogate (nitrophenyl isopropyl methylphosphonate, NIMP) or the VX surrogate NEMP. Levels of reactivation at 2 h after oxime administration were up to 35% while the currently approved therapeutic, 2-PAM, yielded no reduction in brain ChE inhibition. In addition, there was evidence of attenuation of seizure-like behavior with several of the more effective novel oximes, but not 2-PAM. Therefore these novel oximes have demonstrated an ability to reactivate inhibited ChE in brain preparations from two species and in vivo data support their ability to enter the brain and provide a therapeutic action. These novel oximes have the potential to be developed into improved antidotes for nerve agent therapy.

  2. Application of the phylogenetic species concept to Wallemia sebi from house dust and indoor air revealed by multi-locus genealogical concordance.

    Directory of Open Access Journals (Sweden)

    Hai D T Nguyen

    Full Text Available A worldwide survey of Wallemia occurring in house dust and indoor air was conducted. The isolated strains were identified as W. sebi and W. muriae. Previous studies suggested that the W. sebi phylogenetic clade contained cryptic species but conclusive evidence was lacking because only the internal transcribed spacer (ITS marker was analyzed. The ITS and four protein-coding genes (MCM7, RPB1, RPB2, and TSR1 were sequenced for 85 isolates. Based on an initial neighbor joining analysis of the concatenated genes, W. muriae remained monophyletic but four clades were found in W. sebi, which we designated as W. sebi clades 1, 2, 3, and 4. We hypothesized that these clades represent distinct phylogenetic species within the Wallemia sebi species complex (WSSC. We then conducted multiple phylogenetic analyses and demonstrated genealogical concordance, which supports the existence of four phylogenetic species within the WSSC. Geographically, W. muriae was only found in Europe, W. sebi clade 3 was only found in Canada, W. sebi clade 4 was found in subtropical regions, while W. sebi clade 1 and 2 were found worldwide. Haplotype analysis showed that W. sebi clades 1 and 2 had multiple haplotypes while W. sebi clades 3 and 4 had one haplotype and may have been under sampled. We describe W. sebi clades 2, 3, and 4 as new species in a companion study.

  3. Step process for selecting and testing surrogates and indicators of afrotemperate forest invertebrate diversity.

    Directory of Open Access Journals (Sweden)

    Charmaine Uys

    Full Text Available BACKGROUND: The diversity and complexity of invertebrate communities usually result in their exclusion from conservation activities. Here we provide a step process for assessing predominantly ground-dwelling Afrotemperate forest invertebrates' (earthworms, centipedes, millipedes, ants, molluscs potential as surrogates for conservation and indicators for monitoring. We also evaluated sampling methods (soil and litter samples, pitfall traps, active searching quadrats and tree beating and temporal (seasonal effects. METHODOLOGY/PRINCIPAL FINDINGS: Lack of congruence of species richness across taxa indicated poor surrogacy potential for any of the focus taxa. Based on abundance and richness, seasonal stability, and ease of sampling, molluscs were the most appropriate taxon for use in monitoring of disturbance impacts. Mollusc richness was highest in March (Antipodal late summer wet season. The most effective and efficient methods were active searching quadrats and searching litter samples. We tested the effectiveness of molluscs as indicators for monitoring by contrasting species richness and community structure in burned relative to unburned forests. Both species richness and community structure changed significantly with burning. Some mollusc species (e.g. Macroptychia africana showed marked negative responses to burning, and these species have potential for use as indicators. CONCLUSIONS/SIGNIFICANCE: Despite habitat type (i.e., Afrotemperate forest being constant, species richness and community structure varied across forest patches. Therefore, in conservation planning, setting targets for coarse filter features (e.g., habitat type requires fine filter features (e.g., localities for individual species. This is especially true for limited mobility taxa such as those studied here. Molluscs have high potential for indicators for monitoring, and this requires broader study.

  4. Application of the phylogenetic species concept to Wallemia sebi from house dust and indoor air revealed by multi-locus genealogical concordance

    NARCIS (Netherlands)

    Nguyen, Hai D T; Jančič, Sašo; Meijer, Martin; Tanney, Joey B; Zalar, Polona; Gunde-Cimerman, Nina; Seifert, Keith A

    2015-01-01

    A worldwide survey of Wallemia occurring in house dust and indoor air was conducted. The isolated strains were identified as W. sebi and W. muriae. Previous studies suggested that the W. sebi phylogenetic clade contained cryptic species but conclusive evidence was lacking because only the internal t

  5. Surrogate model based iterative ensemble smoother for subsurface flow data assimilation

    Science.gov (United States)

    Chang, Haibin; Liao, Qinzhuo; Zhang, Dongxiao

    2017-02-01

    Subsurface geological formation properties often involve some degree of uncertainty. Thus, for most conditions, uncertainty quantification and data assimilation are necessary for predicting subsurface flow. The surrogate model based method is one common type of uncertainty quantification method, in which a surrogate model is constructed for approximating the relationship between model output and model input. Based on the prediction ability, the constructed surrogate model can be utilized for performing data assimilation. In this work, we develop an algorithm for implementing an iterative ensemble smoother (ES) using the surrogate model. We first derive an iterative ES scheme using a regular routine. In order to utilize surrogate models, we then borrow the idea of Chen and Oliver (2013) to modify the Hessian, and further develop an independent parameter based iterative ES formula. Finally, we establish the algorithm for the implementation of iterative ES using surrogate models. Two surrogate models, the PCE surrogate and the interpolation surrogate, are introduced for illustration. The performances of the proposed algorithm are tested by synthetic cases. The results show that satisfactory data assimilation results can be obtained by using surrogate models that have sufficient accuracy.

  6. Can taxonomic richness be used as a surrogate for phylogenetic distinctness indices for ranking areas for conservation?

    Directory of Open Access Journals (Sweden)

    Pérez-Losada, M.

    2003-06-01

    Full Text Available Several methods have been proposed for evaluating area conservation priorities. Here the performance of traditional approaches (taxonomic richness versus newer methods of phylogenetic distinctness is compared using the results and data from three different molecular studies: crayfish from the central United States and Australia, and Aeglidae freshwater crabs from Chile. To a large extent rankings based on species and genus richness agree with rankings based on taxonomic, phylogenetic and genetic diversity, thus suggesting that taxonomic richness methods may be used as a surrogate for the phylogenetic distinctness methods for the purpose of prioritizing reserve areas for conservation.

  7. Concepts of formal concept analysis

    Science.gov (United States)

    Žáček, Martin; Homola, Dan; Miarka, Rostislav

    2017-07-01

    The aim of this article is apply of Formal Concept Analysis on concept of world. Formal concept analysis (FCA) as a methodology of data analysis, information management and knowledge representation has potential to be applied to a verity of linguistic problems. FCA is mathematical theory for concepts and concept hierarchies that reflects an understanding of concept. Formal concept analysis explicitly formalizes extension and intension of a concept, their mutual relationships. A distinguishing feature of FCA is an inherent integration of three components of conceptual processing of data and knowledge, namely, the discovery and reasoning with concepts in data, discovery and reasoning with dependencies in data, and visualization of data, concepts, and dependencies with folding/unfolding capabilities.

  8. Uncertainty quantification of squeal instability via surrogate modelling

    Science.gov (United States)

    Nobari, Amir; Ouyang, Huajiang; Bannister, Paul

    2015-08-01

    One of the major issues that car manufacturers are facing is the noise and vibration of brake systems. Of the different sorts of noise and vibration, which a brake system may generate, squeal as an irritating high-frequency noise costs the manufacturers significantly. Despite considerable research that has been conducted on brake squeal, the root cause of squeal is still not fully understood. The most common assumption, however, is mode-coupling. Complex eigenvalue analysis is the most widely used approach to the analysis of brake squeal problems. One of the major drawbacks of this technique, nevertheless, is that the effects of variability and uncertainty are not included in the results. Apparently, uncertainty and variability are two inseparable parts of any brake system. Uncertainty is mainly caused by friction, contact, wear and thermal effects while variability mostly stems from the manufacturing process, material properties and component geometries. Evaluating the effects of uncertainty and variability in the complex eigenvalue analysis improves the predictability of noise propensity and helps produce a more robust design. The biggest hurdle in the uncertainty analysis of brake systems is the computational cost and time. Most uncertainty analysis techniques rely on the results of many deterministic analyses. A full finite element model of a brake system typically consists of millions of degrees-of-freedom and many load cases. Running time of such models is so long that automotive industry is reluctant to do many deterministic analyses. This paper, instead, proposes an efficient method of uncertainty propagation via surrogate modelling. A surrogate model of a brake system is constructed in order to reproduce the outputs of the large-scale finite element model and overcome the issue of computational workloads. The probability distribution of the real part of an unstable mode can then be obtained by using the surrogate model with a massive saving of

  9. Compaction behavior of surrogate degraded emplaced WIPP waste.

    Energy Technology Data Exchange (ETDEWEB)

    Broome, Scott Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bronowski, David R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kuthakun, Souvanny James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herrick, Courtney Grant [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pfeifle, Thomas W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of degraded Waste Isolation Pilot Plant (WIPP) containers and TRU waste materials at the end of the 10,000 year regulatory period. Testing consists of hydrostatic, triaxial, and uniaxial strain tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, and rubbers (CPR). Axial, lateral, and volumetric strain and axial, lateral, and pore stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk moduli of the samples measured using this technique were consistent with those measured using more conventional methods. The second technique involved performing triaxial tests under lateral strain control. By limiting the lateral strain to zero by controlling the applied confining pressure while loading the specimen axially in compression, one can maintain a right-circular cylindrical geometry even under large deformations. This technique is preferred over standard triaxial testing methods which result in inhomogeneous deformation or (3z(Bbarreling(3y. (BManifestations of the inhomogeneous deformation included non-uniform stress states, as well as unrealistic Poissons ratios (> 0.5) or those that vary significantly along the length of the specimen. Zero lateral strain controlled tests yield a more uniform stress state, and admissible and uniform values of Poissons ratio.

  10. Surrogate based approaches to parameter inference in ocean models

    KAUST Repository

    Knio, Omar

    2016-01-06

    This talk discusses the inference of physical parameters using model surrogates. Attention is focused on the use of sampling schemes to build suitable representations of the dependence of the model response on uncertain input data. Non-intrusive spectral projections and regularized regressions are used for this purpose. A Bayesian inference formalism is then applied to update the uncertain inputs based on available measurements or observations. To perform the update, we consider two alternative approaches, based on the application of Markov Chain Monte Carlo methods or of adjoint-based optimization techniques. We outline the implementation of these techniques to infer dependence of wind drag, bottom drag, and internal mixing coefficients.

  11. Diesel Surrogate Fuels for Engine Testing and Chemical-Kinetic Modeling: Compositions and Properties

    Science.gov (United States)

    Mueller, Charles J.; Cannella, William J.; Bays, J. Timothy; Bruno, Thomas J.; DeFabio, Kathy; Dettman, Heather D.; Gieleciak, Rafal M.; Huber, Marcia L.; Kweon, Chol-Bum; McConnell, Steven S.; Pitz, William J.; Ratcliff, Matthew A.

    2016-01-01

    The primary objectives of this work were to formulate, blend, and characterize a set of four ultralow-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matching hydrocarbon structural characteristics) relative to the single target diesel fuel upon which the surrogate fuels are based. This approach was taken to assist in determining the minimum level of surrogate-fuel compositional accuracy that is required to adequately emulate the performance characteristics of the target fuel under different combustion modes. For each of the four surrogate fuels, an approximately 30 L batch was blended, and a number of the physical and chemical properties were measured. This work documents the surrogate-fuel creation process and the results of the property measurements. PMID:27330248

  12. Fast and accurate prediction of numerical relativity waveforms from binary black hole mergers using surrogate models

    CERN Document Server

    Blackman, Jonathan; Galley, Chad R; Szilagyi, Bela; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A

    2015-01-01

    Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second dependin...

  13. Unsteady Extinction of Opposed Jet Ethylene/Methane HIFiRE Surrogate Fuel Mixtures vs Air

    Science.gov (United States)

    Vaden, Sarah N.; Debes, Rachel L.; Lash, E. Lara; Burk, Rachel S.; Boyd, C. Merritt; Wilson, Lloyd G.; Pellett, Gerald L.

    2009-01-01

    A unique idealized study of the subject fuel vs. air systems was conducted using an Oscillatory-input Opposed Jet Burner (OOJB) system and a newly refined analysis. Extensive dynamic-extinction measurements were obtained on unanchored (free-floating) laminar Counter Flow Diffusion Flames (CFDFs) at 1-atm, stabilized by steady input velocities (e.g., U(sub air)) and perturbed by superimposed in-phase sinusoidal velocity inputs at fuel and air nozzle exits. Ethylene (C2H4) and methane (CH4), and intermediate 64/36 and 15/85 molar percent mixtures were studied. The latter gaseous surrogates were chosen earlier to mimic ignition and respective steady Flame Strengths (FS = U(sub air)) of vaporized and cracked, and un-cracked, JP-7 "like" kerosene for a Hypersonic International Flight Research Experimentation (HIFiRE) scramjet. For steady idealized flameholding, the 100% C2H4 flame is respectively approx. 1.3 and approx.2.7 times stronger than a 64/36 mix and CH4; but is still 12.0 times weaker than a 100% H2-air flame. Limited Hot-Wire (HW) measurements of velocity oscillations at convergent-nozzle exits, and more extensive Probe Microphone (PM) measurements of acoustic pressures, were used to normalize Dynamic FSs, which decayed linearly with pk/pk U(sub air) (velocity magnitude, HW), and also pk/pk P (pressure magnitude, PM). Thus Dynamic Flame Weakening (DFW) is defined as % decrease in FS per Pascal of pk/pk P oscillation, namely, DFW = -100 d(U(sub air)/U(sub air),0Hz)/d(pkpk P). Key findings are: (1) Ethylene flames are uniquely strong and resilient to extinction by oscillating inflows below 150 Hz; (2) Methane flames are uniquely weak; (3) Ethylene / methane surrogate flames are disproportionately strong with respect to ethylene content; and (4) Flame weakening is consistent with limited published results on forced unsteady CFDFs. Thus from 0 to approx. 10 Hz and slightly higher, lagging diffusive responses of key species led to progressive phase lags (relative

  14. Tropical coastal habitats as surrogates of fish community structure, grazing, and fisheries value.

    Science.gov (United States)

    Harborne, Alastair R; Mumby, Peter J; Kappel, Carrie V; Dahlgren, Craig P; Micheli, Fiorenza; Holmes, Katherine E; Brumbaugh, Daniel R

    2008-10-01

    Habitat maps are frequently invoked as surrogates of biodiversity to aid the design of networks of marine reserves. Maps are used to maximize habitat heterogeneity in reserves because this is likely to maximize the number of species protected. However, the technique's efficacy is limited by intra-habitat variability in the species present and their abundances. Although communities are expected to vary among patches of the same habitat, this variability is poorly documented and rarely incorporated into reserve planning. To examine intra-habitat variability in coral-reef fishes, we generated a data set from eight tropical coastal habitats and six islands in the Bahamian archipelago using underwater visual censuses. Firstly, we provide further support for habitat heterogeneity as a surrogate of biodiversity as each predefined habitat type supported a distinct assemblage of fishes. Intra-habitat variability in fish community structure at scales of hundreds of kilometers (among islands) was significant in at least 75% of the habitats studied, depending on whether presence/absence, density, or biomass data were used. Intra-habitat variability was positively correlated with the mean number of species in that habitat when density and biomass data were used. Such relationships provide a proxy for the assessment of intra-habitat variability when detailed quantitative data are scarce. Intra-habitat variability was examined in more detail for one habitat (forereefs visually dominated by Montastraea corals). Variability in community structure among islands was driven by small, demersal families (e.g., territorial pomacentrid and labrid fishes). Finally, we examined the ecological and economic significance of intra-habitat variability in fish assemblages on Montastraea reefs by identifying how this variability affects the composition and abundances of fishes in different functional groups, the key ecosystem process of parrotfish grazing, and the ecosystem service of value of

  15. Determining High-Quality Critical Body Residues for Multiple Species and Chemicals by Applying Improved Experimental Design and Data Interpretation Concepts

    DEFF Research Database (Denmark)

    van der Heijden, Stephan A.; Hermens, Joop L. M.; Sinnige, Theo L.

    2015-01-01

    Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept...... provides clear advantages, because it links effects directly to the internal exposure. Using CBRs instead of external concentrations should therefore reduce variability. For compounds that act via narcosis even a constant CBR has been proposed. Despite the expected uniformity, CBR values......-defined test protocol for accurately and precisely measuring CBR data, involving improved (passive) dosing, sampling, and processing of organisms. The chemicals 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 2,3,4-trichloroaniline, 2,3,5,6-tetrachloroaniline, 4-chloro-3-methylphenol, pentylbenzene, pyrene...

  16. The development and experimental validation of a reduced ternary kinetic mechanism for the auto-ignition at HCCI conditions, proposing a global reaction path for ternary gasoline surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Machrafi, Hatim; Cavadias, Simeon; Amouroux, Jacques [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France)

    2009-02-15

    To acquire a high amount of information of the behaviour of the Homogeneous Charge Compression Ignition (HCCI) auto-ignition process, a reduced surrogate mechanism has been composed out of reduced n-heptane, iso-octane and toluene mechanisms, containing 62 reactions and 49 species. This mechanism has been validated numerically in a 0D HCCI engine code against more detailed mechanisms (inlet temperature varying from 290 to 500 K, the equivalence ratio from 0.2 to 0.7 and the compression ratio from 8 to 18) and experimentally against experimental shock tube and rapid compression machine data from the literature at pressures between 9 and 55 bar and temperatures between 700 and 1400 K for several fuels: the pure compounds n-heptane, iso-octane and toluene as well as binary and ternary mixtures of these compounds. For this validation, stoichiometric mixtures and mixtures with an equivalence ratio of 0.5 are used. The experimental validation is extended by comparing the surrogate mechanism to experimental data from an HCCI engine. A global reaction pathway is proposed for the auto-ignition of a surrogate gasoline, using the surrogate mechanism, in order to show the interactions that the three compounds can have with one another during the auto-ignition of a ternary mixture. (author)

  17. Combining endangered plants and animals as surrogates to identify priority conservation areas in Yunnan, China

    OpenAIRE

    Feiling Yang; Jinming Hu; Ruidong Wu

    2016-01-01

    Suitable surrogates are critical for identifying optimal priority conservation areas (PCAs) to protect regional biodiversity. This study explored the efficiency of using endangered plants and animals as surrogates for identifying PCAs at the county level in Yunnan, southwest China. We ran the Dobson algorithm under three surrogate scenarios at 75% and 100% conservation levels and identified four types of PCAs. Assessment of the protection efficiencies of the four types of PCAs showed that end...

  18. Surrogate Mobility and Orientation Affect the Early Neurobehavioral Development of Infant Rhesus Macaques (Macaca mulatta)

    OpenAIRE

    Amanda M Dettmer; Ruggerio, Angela M.; Novak, Melinda A.; Meyer, Jerrold S.; Suomi, Stephen J.

    2008-01-01

    A biological mother’s movement appears necessary for optimal development in infant monkeys. However, nursery-reared monkeys are typically provided with inanimate surrogate mothers that move very little. The purpose of this study was to evaluate the effects of a novel, highly mobile surrogate mother on motor development, exploration, and reactions to novelty. Six infant rhesus macaques (Macaca mulatta) were reared on mobile hanging surrogates (MS) and compared to six infants reared on standard...

  19. Professional confidence: a concept analysis.

    Science.gov (United States)

    Holland, Kathlyn; Middleton, Lyn; Uys, Leana

    2012-03-01

    Professional confidence is a concept that is frequently used and or implied in occupational therapy literature, but often without specifying its meaning. Rodgers's Model of Concept Analysis was used to analyse the term "professional confidence". Published research obtained from a federated search in four health sciences databases was used to inform the concept analysis. The definitions, attributes, antecedents, and consequences of professional confidence as evidenced in the literature are discussed. Surrogate terms and related concepts are identified, and a model case of the concept provided. Based on the analysis, professional confidence can be described as a dynamic, maturing personal belief held by a professional or student. This includes an understanding of and a belief in the role, scope of practice, and significance of the profession, and is based on their capacity to competently fulfil these expectations, fostered through a process of affirming experiences. Developing and fostering professional confidence should be nurtured and valued to the same extent as professional competence, as the former underpins the latter, and both are linked to professional identity.

  20. Tailoring molecularly imprinted polymer beads for alternariol recognition and analysis by a screening with mycotoxin surrogates.

    Science.gov (United States)

    Abou-Hany, Rahma A G; Urraca, Javier L; Descalzo, Ana B; Gómez-Arribas, Lidia N; Moreno-Bondi, María C; Orellana, Guillermo

    2015-12-18

    Molecularly imprinted porous polymer microspheres have been prepared for selective binding of alternariol (AOH), a phenolic mycotoxin produced by Alternaria fungi. In order to lead the synthesis of recognition materials, four original AOH surrogates have been designed, prepared and characterized. They bear different number of phenol groups in various positions and different degree of O-methylation on the dibenzo[b,d]pyran-6-one skeleton. A comprehensive library of mixtures of basic, acidic or neutral monomers, with divinylbenzene or ethyleneglycol dimethacrylate as cross-linkers, were polymerized at a small scale in the presence of the four molecular mimics of the toxin molecule. This polymer screening has allowed selection of the optimal composition of the microbeads (N-(2-aminoethyl)methacrylamide, EAMA, and ethylene glycol dimethacrylate). The latter are able to bind AOH in water-acetonitrile (80:20, v/v) with an affinity constant of 109±10mM(-1) and a total number of binding sites of 35±2μmolg(-1), being alternariol monomethylether the only competitor species. Moreover, (1)H NMR titrations have unveiled a 1:2 surrogate-to-EAMA stoichiometry, the exact interaction sites and a binding constant of 1.5×10(4)M(-2). A molecularly imprinted solid phase extraction (MISPE) method has been optimized for selective isolation of the mycotoxin from aqueous samples upon a discriminating wash with 3mL of acetonitrile/water (20:80, v/v) followed by determination by HPLC with fluorescence detection. The method has been applied, in combination to ultrasound-assisted extraction, to the analysis of AOH in tomato samples fortified with the mycotoxin at five concentration levels (33-110μgkg(-1)), with recoveries in the range of 81-103% (RSD n=6). To the best of our knowledge, this is the first imprinted material capable of molecularly recognizing this widespread food contaminant.

  1. A reaction mechanism for gasoline surrogate fuels for large polycyclic aromatic hydrocarbons

    KAUST Repository

    Raj, Abhijeet

    2012-02-01

    This work aims to develop a reaction mechanism for gasoline surrogate fuels (n-heptane, iso-octane and toluene) with an emphasis on the formation of large polycyclic aromatic hydrocarbons (PAHs). Starting from an existing base mechanism for gasoline surrogate fuels with the largest chemical species being pyrene (C 16H 10), this new mechanism is generated by adding PAH sub-mechanisms to account for the formation and growth of PAHs up to coronene (C 24H 12). The density functional theory (DFT) and the transition state theory (TST) have been adopted to evaluate the rate constants for several PAH reactions. The mechanism is validated in the premixed laminar flames of n-heptane, iso-octane, benzene and ethylene. The characteristics of PAH formation in the counterflow diffusion flames of iso-octane/toluene and n-heptane/toluene mixtures have also been tested for both the soot formation and soot formation/oxidation flame conditions. The predictions of the concentrations of large PAHs in the premixed flames having available experimental data are significantly improved with the new mechanism as compared to the base mechanism. The major pathways for the formation of large PAHs are identified. The test of the counterflow diffusion flames successfully predicts the PAH behavior exhibiting a synergistic effect observed experimentally for the mixture fuels, irrespective of the type of flame (soot formation flame or soot formation/oxidation flame). The reactions that lead to this synergistic effect in PAH formation are identified through the rate-of-production analysis. © 2011 The Combustion Institute.

  2. Generation of Hydroxyl Radicals from Dissolved Transition Metals in Surrogate Lung Fluid Solutions.

    Science.gov (United States)

    Vidrio, Edgar; Jung, Heejung; Anastasio, Cort

    2008-01-01

    Epidemiological research has linked exposure to atmospheric particulate matter (PM) to several adverse health effects, including cardiovascular and pulmonary morbidity and mortality. Despite these links, the mechanisms by which PM causes adverse health effects are poorly understood. The generation of hydroxyl radical (.OH) and other reactive oxygen species (ROS) through transition metal-mediated pathways is one of the main hypotheses for PM toxicity. In order to better understand the ability of particulate transition metals to produce ROS, we have quantified the amounts of .OH produced from dissolved iron and copper in a cell-free, surrogate lung fluid (SLF). We also examined how two important biological molecules, citrate and ascorbate, affect the generation of .OH by these metals. We have found that Fe(II) and Fe(III) produce little .OH in the absence of ascorbate and citrate, but that they efficiently make .OH in the presence of ascorbate and this is further enhanced when citrate is also added. In the presence of ascorbate, with or without citrate, the oxidation state of iron makes little difference on the amount of .OH formed after 24 hours. In the case of Cu(II), the production of .OH is greatly enhanced in the presence of ascorbate, but is inhibited by the addition of citrate. The mechanism for this effect is unclear, but appears to involve formation of a citrate-copper complex that is apparently less reactive than free, aquated copper in either the generation of HOOH or in the Fenton-like reaction of copper with HOOH to make .OH. By quantifying the amount of .OH that Fe and Cu can produce in surrogate lung fluid, we have provided a first step into being able to predict the amounts of .OH that can be produced in the human lung from exposure to PM containing known amounts of transition metals.

  3. Evaluation of the use of surrogate Laminaria digitata in eco-hydraulic laboratory experiments

    Institute of Scientific and Technical Information of China (English)

    PAUL Maike; HENRY Pierre-Yves T

    2014-01-01

    Inert surrogates can avoid husbandry and adaptation problems of live vegetation in laboratories. Surrogates are generally used for experiments on vegetation-hydrodynamics interactions, but it is unclear how well they replicate field conditions. Here, surrogates for the brown macroalgae Laminaria digitata were developed to reproduce its hydraulic roughness. Plant shape, stiffness and buoyancy of L. digitata were evaluated and compared to the properties of inert materials. Different surrogate materials and shapes were exposed to unidirectional flow. It is concluded that buoyancy is an important factor in low flow conditions and a basic shape might be sufficient to model complex shaped plants resulting in the same streamlined shape.

  4. The use of surrogate endpoints in regulating medicines for cardio-renal disease: opinions of stakeholders.

    Directory of Open Access Journals (Sweden)

    Bauke Schievink

    Full Text Available AIM: There is discussion whether medicines can be authorized on the market based on evidence from surrogate endpoints. We assessed opinions of different stakeholders on this topic. METHODS: We conducted an online questionnaire that targeted various stakeholder groups (regulatory agencies, pharmaceutical industry, academia, relevant public sector organisations and medical specialties (cardiology or nephrology vs. other. Participants were enrolled through purposeful sampling. We inquired for conditions under which surrogate endpoints can be used, the validity of various cardio-renal biomarkers and new approaches for biomarker use. RESULTS: Participants agreed that surrogate endpoints can be used when the surrogate is scientifically valid (5-point Likert response format, mean score: 4.3, SD: 0.9 or when there is an unmet clinical need (mean score: 3.8, SD: 1.2. Industry participants agreed to a greater extent than regulators and academics. However, out of four proposed surrogates (blood pressure (BP, HbA1c, albuminuria, CRP for cardiovascular outcomes or end-stage renal disease, only use of BP for cardiovascular outcomes was deemed moderately accurate (mean: 3.6, SD: 1.1. Specialists in cardiology or nephrology tended to be more positive about the use of surrogate endpoints. CONCLUSION: Stakeholders in drug development do not oppose to the use of surrogate endpoints in drug marketing authorization, but most surrogates are not considered valid. To solve this impasse, increased efforts are required to validate surrogate endpoints and to explore alternative ways to use them.

  5. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-20

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO{sub 2} production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  6. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-17

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  7. Simultaneous Thermal Analysis of Remediated Nitrate Salt Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Wayne, David Matthew [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-13

    The actinide engineering and science group (MET-1) have completed simultaneous thermal analysis and offgas analysis by mass spectrometry (STA-MS) of remediated nitrate salt (RNS) surrogates formulated by the high explosives science and technology group (M-7). The 1.0 to 1.5g surrogate samples were first analyzed as received, then a new set was analyzed with 100-200mL 10M HNO3 +0.3 MHF added, and a third set was analyzed after 200 mL of a concentrated Pu-AM spike (in 10M HNO3 +0.3 MHF) was added. The acid and spike solutions were formulated by the actinide analytical chemistry group (C-AAC) using reagent-grade HNO3 and HF, which was also used to dissolve a small quantity of mixed, high-fired PuO2/ AmO2 oxide.

  8. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-20

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO{sub 2} production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  9. Detailed chemical kinetic oxidation mechanism for a biodiesel surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2007-09-17

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of methyl decanoate, a surrogate for biodiesel fuels. This model has been built by following the rules established by Curran et al. for the oxidation of n-heptane and it includes all the reactions known to be pertinent to both low and high temperatures. Computed results have been compared with methyl decanoate experiments in an engine and oxidation of rapeseed oil methyl esters in a jet stirred reactor. An important feature of this mechanism is its ability to reproduce the early formation of carbon dioxide that is unique to biofuels and due to the presence of the ester group in the reactant. The model also predicts ignition delay times and OH profiles very close to observed values in shock tube experiments fueled by n-decane. These model capabilities indicate that large n-alkanes can be good surrogates for large methyl esters and biodiesel fuels to predict overall reactivity, but some kinetic details, including early CO2 production from biodiesel fuels, can be predicted only by a detailed kinetic mechanism for a true methyl ester fuel. The present methyl decanoate mechanism provides a realistic kinetic tool for simulation of biodiesel fuels.

  10. Bayesian Calibration of the Community Land Model using Surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Jaideep; Hou, Zhangshuan; Huang, Maoyi; Sargsyan, K.; Swiler, Laura P.

    2015-01-01

    We present results from the Bayesian calibration of hydrological parameters of the Community Land Model (CLM), which is often used in climate simulations and Earth system models. A statistical inverse problem is formulated for three hydrological parameters, conditioned on observations of latent heat surface fluxes over 48 months. Our calibration method uses polynomial and Gaussian process surrogates of the CLM, and solves the parameter estimation problem using a Markov chain Monte Carlo sampler. Posterior probability densities for the parameters are developed for two sites with different soil and vegetation covers. Our method also allows us to examine the structural error in CLM under two error models. We find that accurate surrogate models can be created for CLM in most cases. The posterior distributions lead to better prediction than the default parameter values in CLM. Climatologically averaging the observations does not modify the parameters’ distributions significantly. The structural error model reveals a correlation time-scale which can potentially be used to identify physical processes that could be contributing to it. While the calibrated CLM has a higher predictive skill, the calibration is under-dispersive.

  11. Fractional flow reserve as a surrogate for inducible myocardial ischaemia.

    Science.gov (United States)

    van de Hoef, Tim P; Meuwissen, Martijn; Escaned, Javier; Davies, Justin E; Siebes, Maria; Spaan, Jos A E; Piek, Jan J

    2013-08-01

    Documentation of inducible myocardial ischaemia, related to the coronary stenosis of interest, is of increasing importance in lesion selection for percutaneous coronary intervention (PCI). Fractional flow reserve (FFR) is an easily understood, routine diagnostic modality that has become part of daily clinical practice, and is used as a surrogate technique for noninvasive assessment of myocardial ischaemia. However, the application of a single, discrete, cut-off value for FFR-guided lesion selection for PCI, and its adoption in contemporary revascularization guidelines, has limited the requirement for a thorough understanding of the physiological basis of FFR. This limitation constitutes an obstacle for the adequate use and interpretation of this technique, and also for the understanding of new and future modalities of physiological functional intracoronary testing. In this Review, we revisit the fundamental elements of coronary physiology in the absence or presence of coronary artery disease. We provide insight into three essential characteristics of FFR as a diagnostic tool in contemporary clinical practice--the theoretical framework of FFR and its associated limitations; the characteristics and role of FFR as a surrogate for noninvasively assessed myocardial ischaemia; and the requirement and associated caveats of potent vasodilatory drugs to induce maximal vasodilatation of the coronary vascular bed.

  12. The development of radioactive sample surrogates for training and exercises

    Energy Technology Data Exchange (ETDEWEB)

    Martha Finck; Bevin Brush; Dick Jansen; David Chamberlain; Don Dry; George Brooks; Margaret Goldberg

    2012-03-01

    The development of radioactive sample surrogates for training and exercises Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a Radioactive Response Training Range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Members from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive Br-82 isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.

  13. Pan masala advertisements are surrogate for tobacco products.

    Science.gov (United States)

    Sushma, C; Sharang, C

    2005-01-01

    Pan masala is a comparatively recent habit in India and is marketed with and without tobacco. Advertisements of tobacco products have been banned in India since 1st May 2004. The advertisements of plain pan masala, which continue in Indian media, have been suspected to be surrogate for tobacco products bearing the same name. The study was carried out to assess whether these advertisements were for the intended product, or for tobacco products with same brand name. The programme of a popular television Hindi news channel was watched for a 24-h period. Programmes on the same channel and its English counterpart were watched on different days to assess whether the advertisements were repeated. The total duration of telecast of a popular brand of plain pan masala (Pan Parag) was multiplied by the rate charged by the channel to provide the cost of advertisement of this product. The total sale value of the company was multiplied by the proportion of usage of plain pan masala out of gutka plus pan masala habit as observed from a different study, to provide the annual sale value of plain pan masala product under reference. The annual sale value of plain Pan Parag was estimated to be Rs. 67.1 million. The annual cost of the advertisement of the same product on two television channels was estimated at Rs. 244.6 million. The advertisements of plain pan masala seen on Indian television are a surrogate for the tobacco products bearing the same name.

  14. Defining useful surrogates for user participation in online medical learning.

    LENUS (Irish Health Repository)

    Beddy, Peter

    2012-02-01

    "School for Surgeons" is a web-based distance learning program which provides online clinical-based tutorials to surgical trainees. Our aim was to determine surrogates of active participation and to assess the efficacy of methods to improve usage. Server logs of the 82 participants in the "School for Surgeons" were assessed for the two terms of the first year of the program. Data collected included total time online, mean session time, page requests, numbers of sessions online and the total number of assignments. An intervention regarding comparative peer usage patterns was delivered to the cohort between terms one and two. Of the 82 trainees enrolled, 83% (85% second term) logged into the program. Of all participants 88% (97% second term) submitted at least one assignment. Median submissions were four (eight second term) per trainee. Assignment submission closely correlated with number of sessions, total time online, downloads and page requests. Peer-based comparative feedback resulted in a significant increase in the number of assignments submitted (p < 0.01). Despite its recent introduction, "School for Surgeons" has a good participation rate. Assignment submission is a valid surrogate for usage. Students can be encouraged to move from passive observation to active participation in a virtual learning environment by providing structured comparative feedback ranking their performance.

  15. Proper Orthogonal Decomposition as Surrogate Model for Aerodynamic Optimization

    Directory of Open Access Journals (Sweden)

    Valentina Dolci

    2016-01-01

    Full Text Available A surrogate model based on the proper orthogonal decomposition is developed in order to enable fast and reliable evaluations of aerodynamic fields. The proposed method is applied to subsonic turbulent flows and the proper orthogonal decomposition is based on an ensemble of high-fidelity computations. For the construction of the ensemble, fractional and full factorial planes together with central composite design-of-experiment strategies are applied. For the continuous representation of the projection coefficients in the parameter space, response surface methods are employed. Three case studies are presented. In the first case, the boundary shape of the problem is deformed and the flow past a backward facing step with variable step slope is studied. In the second case, a two-dimensional flow past a NACA 0012 airfoil is considered and the surrogate model is constructed in the (Mach, angle of attack parameter space. In the last case, the aerodynamic optimization of an automotive shape is considered. The results demonstrate how a reduced-order model based on the proper orthogonal decomposition applied to a small number of high-fidelity solutions can be used to generate aerodynamic data with good accuracy at a low cost.

  16. Bayesian calibration of the Community Land Model using surrogates

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Jaideep; Hou, Zhangshuan; Huang, Maoyi; Swiler, Laura Painton

    2014-02-01

    We present results from the Bayesian calibration of hydrological parameters of the Community Land Model (CLM), which is often used in climate simulations and Earth system models. A statistical inverse problem is formulated for three hydrological parameters, conditional on observations of latent heat surface fluxes over 48 months. Our calibration method uses polynomial and Gaussian process surrogates of the CLM, and solves the parameter estimation problem using a Markov chain Monte Carlo sampler. Posterior probability densities for the parameters are developed for two sites with different soil and vegetation covers. Our method also allows us to examine the structural error in CLM under two error models. We find that surrogate models can be created for CLM in most cases. The posterior distributions are more predictive than the default parameter values in CLM. Climatologically averaging the observations does not modify the parameters' distributions significantly. The structural error model reveals a correlation time-scale which can be used to identify the physical process that could be contributing to it. While the calibrated CLM has a higher predictive skill, the calibration is under-dispersive.

  17. Vertical Flume Testing of WIPP Surrogate Waste Materials

    Science.gov (United States)

    Herrick, C. G.; Schuhen, M.; Kicker, D.

    2013-12-01

    The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy geological repository for the permanent disposal of defense-related transuranic (TRU) waste. The waste is emplaced in rooms excavated in the bedded Salado salt formation at a depth of 655 m below ground surface. After emplacement of the waste, the repository will be sealed and decommissioned. The DOE demonstrates compliance with 40 CFR 194 by means of performance assessment (PA) calculations conducted by Sandia National Laboratories. WIPP PA calculations estimate the probability and consequences of radionuclide releases for a 10,000 year regulatory period. Human intrusion scenarios include cases in which a future borehole is drilled through the repository. Drilling mud flowing up the borehole will apply a hydrodynamic shear stress to the borehole wall which could result in erosion of the waste and radionuclides being carried up the borehole. WIPP PA uses the parameter TAUFAIL to represent the shear strength of the degraded waste. The hydrodynamic shear strength can only be measured experimentally by flume testing. Flume testing is typically performed horizontally, mimicking stream or ocean currents. However, in a WIPP intrusion event, the drill bit would penetrate the degraded waste and drilling mud would flow up the borehole in a predominantly vertical direction. In order to simulate this, a flume was designed and built so that the eroding fluid enters an enclosed vertical channel from the bottom and flows up past a specimen of surrogate waste material. The sample is pushed into the current by a piston attached to a step motor. A qualified data acquisition system controls and monitors the fluid's flow rate, temperature, pressure, and conductivity and the step motor's operation. The surrogate materials used correspond to a conservative estimate of degraded TRU waste at the end of the regulatory period. The recipes were previously developed by SNL based on anticipated future states of the waste

  18. Fish fins as non-lethal surrogates for muscle tissues in freshwater food web studies using stable isotopes.

    Science.gov (United States)

    Hette Tronquart, Nicolas; Mazeas, Laurent; Reuilly-Manenti, Liana; Zahm, Amandine; Belliard, Jérôme

    2012-07-30

    Dorsal white muscle is the standard tissue analysed in fish trophic studies using stable isotope analyses. However, sampling white muscle often implies the sacrifice of fish. Thus, we examined whether the non-lethal sampling of fin tissue can substitute muscle sampling in food web studies. Analysing muscle and fin δ(15)N and δ(13)C values of 466 European freshwater fish (14 species) with an elemental analyser coupled with an isotope ratio mass spectrometer, we compared the isotope values of the two tissues. Correlations between fin and muscle isotope ratios were examined for all fish together and specifically for 12 species. We further proposed four methods of assessing muscle from fin isotope ratios and estimated the errors made using these muscle surrogates. Despite significant differences between isotope values of the two tissues, fin and muscle isotopic signals are strongly correlated. Muscle values, estimated with raw fin isotope ratios (1st method), induce an error of ca. 1‰ for both isotopes. In comparison, specific (2nd method) or general (3rd method) correlations provide meaningful corrections of fin isotope ratios (errors muscle estimates (errors >0.8‰). There is little chance that a global model can be created. However, the 2nd and 3rd methods of estimating muscle values from fin isotope ratios should provide an acceptable level of error for the studies of European freshwater food web. We thus recommend that future studies use fin tissue as a non-lethal surrogate for muscle. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Extensive range overlap between heliconiine sister species: evidence for sympatric speciation in butterflies?

    Science.gov (United States)

    Rosser, Neil; Kozak, Krzysztof M; Phillimore, Albert B; Mallet, James

    2015-06-30

    Sympatric speciation is today generally viewed as plausible, and some well-supported examples exist, but its relative contribution to biodiversity remains to be established. We here quantify geographic overlap of sister species of heliconiine butterflies, and use age-range correlations and spatial simulations of the geography of speciation to infer the frequency of sympatric speciation. We also test whether shifts in mimetic wing colour pattern, host plant use and climate niche play a role in speciation, and whether such shifts are associated with sympatry. Approximately a third of all heliconiine sister species pairs exhibit near complete range overlap, and analyses of the observed patterns of range overlap suggest that sympatric speciation contributes 32%-95% of speciation events. Müllerian mimicry colour patterns and host plant choice are highly labile traits that seem to be associated with speciation, but we find no association between shifts in these traits and range overlap. In contrast, climatic niches of sister species are more conserved. Unlike birds and mammals, sister species of heliconiines are often sympatric and our inferences using the most recent comparative methods suggest that sympatric speciation is common. However, if sister species spread rapidly into sympatry (e.g. due to their similar climatic niches), then assumptions underlying our methods would be violated. Furthermore, although we find some evidence for the role of ecology in speciation, ecological shifts did not show the associations with range overlap expected under sympatric speciation. We delimit species of heliconiines in three different ways, based on "strict and " "relaxed" biological species concepts (BSC), as well as on a surrogate for the widely-used "diagnostic" version of the phylogenetic species concept (PSC). We show that one reason why more sympatric speciation is inferred in heliconiines than in birds may be due to a different culture of species delimitation in the two

  20. A new and robust method of tethering IgG surrogate antigens on lipid bilayer membranes to facilitate the TIRFM based live cell and single molecule imaging experiments.

    Directory of Open Access Journals (Sweden)

    Shaosen Zhang

    Full Text Available Our understanding of cell-cell interactions has been significantly improved in the past years with the help of Total Internal Reflection Fluorescence Microscope (TIRFM in combination with an antigen presenting system supported by planar lipid bilayer (PLB membranes, which are used to mimic the extensive receptor and ligand interactions within cell-cell contact interface. In TIRFM experiments, it is a challenge to uniformly present ligand molecules in monomeric format on the surface of PLB membranes. Here, we introduce a new and robust method of tethering IgG surrogate antigen ligands on the surface of Ni(2+-containing PLB membranes. In this method, we use a modified D domain from staphylococcal protein A molecule that is fused with an N-terminus polyhistidine tag (H12-D-domain to tether IgG surrogate antigens on Ni(2+-containing PLB membranes. We systematically assessed the specificity and capability of H12-D-domain construct to capture IgG molecules from different species through live cell and single molecule TIRFM imaging. We find that these IgG surrogate antigens tethered by H12-D-domain show better lateral mobility and are more uniformly distributed on PLB membranes than the ones tethered by streptavidin. Neither IgM molecules, nor Fab or F(ab'2 fragments of IgG molecules can be tethered on PLB membranes by H12-D-domain construct. These tethered IgG surrogate antigens strongly induce the formation and accumulation of signaling active antigen receptor microclusters within the immunological synapse in B or T lymphocyte cells. Thus our method provides a new and robust method to tether IgG surrogate antigens or other molecules fused with IgG Fc portion on PLB membranes for TIRFM based molecule imaging experiments.

  1. Foot-mediated incubation: Nazca booby (Sula granti) feet as surrogate brood patches.

    Science.gov (United States)

    Morgan, Stephanie M; Ashley-Ross, Miriam A; Anderson, David J

    2003-01-01

    Incubation in most avian species involves transferring heat from parent to egg through a highly vascularized brood patch. Some birds, however, do not develop a brood patch. Unusual among birds, these species hold their eggs under the webs of their feet, but the role of the feet in heat transfer is uncertain. Often the webs are positioned between the feathered abdomen and the egg during incubation, suggesting that either the abdomen, the feet, or both could transfer heat to the egg. We studied heat transfer from foot webs to eggs during incubation in Nazca boobies by spatially separating the feet from the abdomen using an oversized egg. We found that feet transfer heat to eggs independently of any heat that may be transferred from the abdomen. In addition, we found that incubating boobies had significantly greater vascularization in their foot webs, measured as a percentage of web area covered by vessels, than nonincubating boobies. We also found that males, whether incubating or nonincubating, had significantly less web vascularization than females. We concluded that vascularized Nazca booby feet function in the same way during incubation that vascularized brood patches do, acting as surrogate brood patches.

  2. Comparison of surrogate models with different methods in groundwater remediation process

    Indian Academy of Sciences (India)

    Jiannan Luo; Wenxi Lu

    2014-10-01

    Surrogate modelling is an effective tool for reducing computational burden of simulation optimization. In this article, polynomial regression (PR), radial basis function artificial neural network (RBFANN), and kriging methods were compared for building surrogate models of a multiphase flow simulation model in a simplified nitrobenzene contaminated aquifer remediation problem. In the model accuracy analysis process, a 10-fold cross validation method was adopted to evaluate the approximation accuracy of the three surrogate models. The results demonstrated that: RBFANN surrogate model and kriging surrogate model had acceptable approximation accuracy, and further that kriging model’s approximation accuracy was slightly higher than RBFANN model. However, the PR model demonstrated unacceptably poor approximation accuracy. Therefore, the RBFANN and kriging surrogates were selected and used in the optimization process to identify the most cost-effective remediation strategy at a nitrobenzene-contaminated site. The optimal remediation costs obtained with the two surrogate-based optimization models were similar, and had similar computational burden. These two surrogate-based optimization models are efficient tools for optimal groundwater remediation strategy identification.

  3. Someone to Lean on: Assessment and Implications of Social Surrogate Use in Childhood

    Science.gov (United States)

    Arbeau, Kimberley A.; Coplan, Robert J.; Matheson, Adrienne

    2012-01-01

    A social surrogate is a person who helps a shy individual deal with the stresses of a social situation. Previous research has only investigated social surrogate use in adults. The purpose of the current study was to develop and evaluate a new self-report measure of social surrogacy in middle childhood and to explore the implications of this…

  4. Critical review of norovirus surrogates in food safety research: rationale for considering volunteer studies

    Science.gov (United States)

    The inability to propagate human norovirus (NoV) or to clearly differentiate infectious from noninfectious virus particles have led to the use of surrogate viruses, like feline calicivirus (FCV) and murine norovirus-1 (MNV), which are propagatable in cell culture. The use of surrogates is predicate...

  5. Somatic coliphages as surrogates for enteroviruses in sludge hygienization treatments.

    Science.gov (United States)

    Martín-Díaz, Julia; Casas-Mangas, Raquel; García-Aljaro, Cristina; Blanch, Anicet R; Lucena, Francisco

    2016-01-01

    Conventional bacterial indicators present serious drawbacks giving information about viral pathogens persistence during sludge hygienization treatments. This calls for the search of alternative viral indicators. Somatic coliphages' (SOMCPH) ability for acting as surrogates for enteroviruses was assessed in 47 sludge samples subjected to novel treatment processes. SOMCPH, infectious enteroviruses and genome copies of enteroviruses were monitored. Only one of these groups, the bacteriophages, was present in the sludge at concentrations that allowed the evaluation of treatment's performance. An indicator/pathogen relationship of 4 log10 (PFU/g dw) was found between SOMCPH and infective enteroviruses and their detection accuracy was assessed. The obtained results and the existence of rapid and standardized methods encourage the inclusion of SOMCPH quantification in future sludge directives. In addition, an existing real-time quantitative polymerase chain reaction (RT-qPCR) for enteroviruses was adapted and applied.

  6. A Rigorous Framework for Optimization of Expensive Functions by Surrogates

    Science.gov (United States)

    Booker, Andrew J.; Dennis, J. E., Jr.; Frank, Paul D.; Serafini, David B.; Torczon, Virginia; Trosset, Michael W.

    1998-01-01

    The goal of the research reported here is to develop rigorous optimization algorithms to apply to some engineering design problems for which design application of traditional optimization approaches is not practical. This paper presents and analyzes a framework for generating a sequence of approximations to the objective function and managing the use of these approximations as surrogates for optimization. The result is to obtain convergence to a minimizer of an expensive objective function subject to simple constraints. The approach is widely applicable because it does not require, or even explicitly approximate, derivatives of the objective. Numerical results are presented for a 31-variable helicopter rotor blade design example and for a standard optimization test example.

  7. Sparse polynomial surrogates for aerodynamic computations with random inputs

    CERN Document Server

    Savin, Eric; Peter, Jacques

    2015-01-01

    This paper deals with some of the methodologies used to construct polynomial surrogate models based on generalized polynomial chaos (gPC) expansions for applications to uncertainty quantification (UQ) in aerodynamic computations. A core ingredient in gPC expansions is the choice of a dedicated sampling strategy, so as to define the most significant scenarios to be considered for the construction of such metamodels. A desirable feature of the proposed rules shall be their ability to handle several random inputs simultaneously. Methods to identify the relative "importance" of those variables or uncertain data shall be ideally considered as well. The present work is more particularly dedicated to the development of sampling strategies based on sparsity principles. Sparse multi-dimensional cubature rules based on general one-dimensional Gauss-Jacobi-type quadratures are first addressed. These sets are non nested, but they are well adapted to the probability density functions with compact support for the random in...

  8. High-Temperature Oxidation of Plutonium Surrogate Metals and Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Sparks, Joshua C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Krantz, Kelsie E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Christian, Jonathan H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-07-27

    The Plutonium Management and Disposition Agreement (PMDA) is a nuclear non-proliferation agreement designed to remove 34 tons of weapons-grade plutonium from Russia and the United States. While several removal options have been proposed since the agreement was first signed in 2000, processing the weapons-grade plutonium to mixed-oxide (MOX) fuel has remained the leading candidate for achieving the goals of the PMDA. However, the MOX program has received its share of criticisms, which causes its future to be uncertain. One alternative pathway for plutonium disposition would involve oxidizing the metal followed by impurity down blending and burial in the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico. This pathway was investigated by use of a hybrid microwave and a muffle furnace with Fe and Al as surrogate materials. Oxidation occurred similarly in the microwave and muffle furnace; however, the microwave process time was significantly faster.

  9. Protein prosthesis: β-peptides as reverse-turn surrogates.

    Science.gov (United States)

    Arnold, Ulrich; Huck, Bayard R; Gellman, Samuel H; Raines, Ronald T

    2013-03-01

    The introduction of non-natural modules could provide unprecedented control over folding/unfolding behavior, conformational stability, and biological function of proteins. Success requires the interrogation of candidate modules in natural contexts. Here, expressed protein ligation is used to replace a reverse turn in bovine pancreatic ribonuclease (RNase A) with a synthetic β-dipeptide: β²-homoalanine-β³-homoalanine. This segment is known to adopt an unnatural reverse-turn conformation that contains a 10-membered ring hydrogen bond, but one with a donor-acceptor pattern opposite to that in the 10-membered rings of natural reverse turns. The RNase A variant has intact enzymatic activity, but unfolds more quickly and has diminished conformational stability relative to native RNase A. These data indicate that hydrogen-bonding pattern merits careful consideration in the selection of beneficial reverse-turn surrogates. Copyright © 2012 The Protein Society.

  10. Argan oil improves surrogate markers of CVD in humans.

    Science.gov (United States)

    Sour, Souad; Belarbi, Meriem; Khaldi, Darine; Benmansour, Nassima; Sari, Nassima; Nani, Abdelhafid; Chemat, Farid; Visioli, Francesco

    2012-06-01

    Limited - though increasing - evidence suggests that argan oil might be endowed with potential healthful properties, mostly in the areas of CVD and prostate cancer. We sought to comprehensively determine the effects of argan oil supplementation on the plasma lipid profile and antioxidant status of a group of healthy Algerian subjects, compared with matched controls. A total of twenty healthy subjects consumed 15 g/d of argan oil - with toasted bread - for breakfast, during 4 weeks (intervention group), whereas twenty matched controls followed their habitual diet, but did not consume argan oil. The study lasted 30 d. At the end of the study, argan oil-supplemented subjects exhibited higher plasma vitamin E concentrations, lower total and LDL-cholesterol, lower TAG and improved plasma and cellular antioxidant profile, when compared with controls. In conclusion, we showed that Algerian argan oil is able to positively modulate some surrogate markers of CVD, through mechanisms which warrant further investigation.

  11. Cholesterol paradox: a correlate does not a surrogate make.

    Science.gov (United States)

    DuBroff, Robert

    2017-03-01

    The global campaign to lower cholesterol by diet and drugs has failed to thwart the developing pandemic of coronary heart disease around the world. Some experts believe this failure is due to the explosive rise in obesity and diabetes, but it is equally plausible that the cholesterol hypothesis, which posits that lowering cholesterol prevents cardiovascular disease, is incorrect. The recently presented ACCELERATE trial dumbfounded many experts by failing to demonstrate any cardiovascular benefit of evacetrapib despite dramatically lowering low-density lipoprotein cholesterol and raising high-density lipoprotein cholesterol in high-risk patients with coronary disease. This clinical trial adds to a growing volume of knowledge that challenges the validity of the cholesterol hypothesis and the utility of cholesterol as a surrogate end point. Inadvertently, the cholesterol hypothesis may have even contributed to this pandemic. This perspective critically reviews this evidence and our reluctance to acknowledge contradictory information.

  12. Not all Laminaria digitata are the same! Phenotypic plasticity and the selection of appropriate surrogate macroalgae for ecohydraulic experimentation

    Science.gov (United States)

    Thomas, Robert E.; McLelland, Stuart J.; Henry, Pierre-Yves T.; Paul, Maike; Eiff, Olivier; Evertsen, Antti-Jussi O.; Aberle, Jochen; Teacă, Adrian

    2015-04-01

    not be transported from Norway to the UK, so we used the same species of live macroalgae harvested from a wave-dominated coast in the UK. These algae exhibited longer, narrower and more flexible blades. The same surrogate plants were used in both the field and flume experiments. In all cases, a profiling ADV was used to collect 45 velocity profiles composed of up to seven 35 mm-high profiles collected for 240 s at 100 Hz, at a streamwise spacing of 0.25 m and cross-stream spacing of 0.20 m. The results show that the live macroalgae in the flume simulation exerted less influence on the flow field than the live macroalgae at the field site. In contrast, the "optimized" surrogate macroalgae behaved similarly to the live algae at the field site and yielded similar mean and turbulent velocity fields as our prototype live macroalgae. This emphasizes both the importance of phenotypic plasticity and the importance of selecting surrogates that adequately represent the mean characteristics of the species of interest.

  13. Technological advances in suspended-sediment surrogate monitoring

    Science.gov (United States)

    Gray, John R.; Gartner, Jeffrey W.

    2009-01-01

    Surrogate technologies to continuously monitor suspended sediment show promise toward supplanting traditional data collection methods requiring routine collection and analysis of water samples. Commercially available instruments operating on bulk optic (turbidity), laser optic, pressure difference, and acoustic backscatter principles are evaluated based on cost, reliability, robustness, accuracy, sample volume, susceptibility to biological fouling, and suitable range of mass concentration and particle size distribution. In situ turbidimeters are widely used. They provide reliable data where the point measurements can be reliably correlated to the river's mean cross section concentration value, effects of biological fouling can be minimized, and concentrations remain below the sensor's upper measurement limit. In situ laser diffraction instruments have similar limitations and can cost 6 times the approximate $5000 purchase price of a turbidimeter. However, laser diffraction instruments provide volumetric-concentration data in 32 size classes. Pressure differential instruments measure mass density in a water column, thus integrating substantially more streamflow than a point measurement. They are designed for monitoring medium-to-large concentrations, are generally unaffected by biological fouling, and cost about the same as a turbidimeter. However, their performance has been marginal in field applications. Acoustic Doppler profilers use acoustic backscatter to measure suspended sediment concentrations in orders of magnitude more streamflow than do instruments that rely on point measurements. The technology is relatively robust and generally immune to effects of biological fouling. Cost of a single-frequency device is about double that of a turbidimeter. Multifrequency arrays also provide the potential to resolve concentrations by clay silt versus sand size fractions. Multifrequency hydroacoustics shows the most promise for revolutionizing collection of continuous

  14. Effectiveness of chitosan on the inactivation of enteric viral surrogates.

    Science.gov (United States)

    Davis, Robert; Zivanovic, Svetlana; D'Souza, Doris H; Davidson, P Michael

    2012-10-01

    Chitosan is known to have bactericidal and antifungal activity. Although human noroviruses are the leading cause of non-bacterial gastroenteritis, information on the efficacy of chitosan against foodborne viruses is very limited. The objective of this work was to determine the effectiveness of different molecular weight chitosans against the cultivable human norovirus and enteric virus surrogates, feline calicivirus, FCV-F9, murine norovirus, MNV-1, and bacteriophages, MS2 and phiX174. Five purified chitosans (53, 222, 307, 421, ~1150 kDa) were dissolved in water, 1% acetic acid, or aqueous HCl pH = 4.3, sterilized by membrane filtration, and mixed with equal volume of virus to obtain a final concentration of 0.7% chitosan and 5 log(10) PFU/ml virus. Virus-chitosan suspensions were incubated for 3 h at 37 °C. Untreated viruses in PBS, in PBS with acetic acid, and in PBS with HCl were tested as controls. Each experiment was run in duplicate and replicated at least twice. Water-soluble chitosan (53 kDa) reduced phiX174, MS2, FCV-F9 and MNV-1 titers by 0.59, 2.44, 3.36, and 0.34 log(10) PFU/ml respectively. Chitosans in acetic acid decreased phiX174 by 1.19-1.29, MS2 by 1.88-5.37, FCV-F9 by 2.27-2.94, and MNV-1 by 0.09-0.28 log(10) PFU/ml, respectively. Increasing the MW of chitosan corresponded with an increasing antiviral effect on MS2, but did not appear to play a role for the other three tested viral surrogates. Overall, chitosan treatments showed the greatest reduction for FCV-F9, and MS2 followed by phiX174, and with no significant effect on MNV-1.

  15. Potential cryptosporidium surrogates and evaluation of compressible oocysts

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.Y.; Goodrich, J.A.; Owens, J.H. [Environmental Protection Agency, Cincinnati, OH (United States)] [and others

    1995-10-01

    Cryptosporidium has been recognized as an important waterborne agent of gastroenteritis and a biological contaminant in drinking water. The widespread presence of Cryptosporidium in surface source water and either untreated or insufficiently treated drinking water has led to Cryptosporidium outbreaks in the United States and worldwide. Among the conventional control practices, filtration and high temperature distillation appear to be the potentially viable technologies for protection against Cryptosporidium in drinking water. As employed in many water plants, filtration is likely to be the most practical treatment technology utilized for Cryptosporidium removal in the near future. Consequently, accurate and reliable methods for evaluation of Cryptosporidium removal rates for filtration-based systems are necessary to assist States in determining drinking water quality and complying with the up-coming national standard for Cryptosporidium in drinking water. Furthermore, searching for reliable and non-hazardous surrogates for evaluation of treatment plant efficiency has been intensified because of the potential health risk associated with Cryptosporidium. Additionally, during the filtration procedure Cryptosporidium may squeeze and fold through pores size of the filtration systems that are smaller than the diameter of the organism; a fraction of these Cryptosporidium oocysts may still remain a certain degree of viability. These uncertainties are critical for the evaluation and optimization of filtration-based physical treatment systems. The in-house research studies described below consist of two parts. One is a potential surrogate study using bag filtration systems at the US EPA Test & Evaluation Facility in Cincinnati, Ohio. The second is Cryptosporidium compressibility and viability investigation.

  16. Pan masala advertisements are surrogate for tobacco products

    Directory of Open Access Journals (Sweden)

    Sushma C

    2005-01-01

    Full Text Available BACKGROUND: Pan masala is a comparatively recent habit in India and is marketed with and without tobacco. Advertisements of tobacco products have been banned in India since 1st May 2004. The advertisements of plain pan masala, which continue in Indian media, have been suspected to be surrogate for tobacco products bearing the same name. The study was carried out to assess whether these advertisements were for the intended product, or for tobacco products with same brand name. MATERIALS AND METHODS: The programme of a popular television Hindi news channel was watched for a 24-h period. Programmes on the same channel and its English counterpart were watched on different days to assess whether the advertisements were repeated. The total duration of telecast of a popular brand of plain pan masala (Pan Parag was multiplied by the rate charged by the channel to provide the cost of advertisement of this product. The total sale value of the company was multiplied by the proportion of usage of plain pan masala out of gutka plus pan masala habit as observed from a different study, to provide the annual sale value of plain pan masala product under reference. RESULTS: The annual sale value of plain Pan Parag was estimated to be Rs. 67.1 million. The annual cost of the advertisement of the same product on two television channels was estimated at Rs. 244.6 million. CONCLUSION: The advertisements of plain pan masala seen on Indian television are a surrogate for the tobacco products bearing the same name.

  17. Concept Convergence in Empirical Domains

    Science.gov (United States)

    Ontañón, Santiago; Plaza, Enric

    How to achieve shared meaning is a significant issue when more than one intelligent agent is involved in the same domain. We define the task of concept convergence, by which intelligent agents can achieve a shared, agreed-upon meaning of a concept (restricted to empirical domains). For this purpose we present a framework that, integrating computational argumentation and inductive concept learning, allows a pair of agents to (1) learn a concept in an empirical domain, (2) argue about the concept's meaning, and (3) reach a shared agreed-upon concept definition. We apply this framework to marine sponges, a biological domain where the actual definitions of concepts such as orders, families and species are currently open to discussion. An experimental evaluation on marine sponges shows that concept convergence is achieved, within a reasonable number of interchanged arguments, and reaching short and accurate definitions (with respect to precision and recall).

  18. Learning image based surrogate relevance criterion for atlas selection in segmentation

    Science.gov (United States)

    Zhao, Tingting; Ruan, Dan

    2016-06-01

    Picking geometrically relevant atlases from the whole training set is crucial to multi-atlas based image segmentation, especially with extensive data of heterogeneous quality in the Big Data era. Unfortunately, there is very limited understanding of how currently used image similarity criteria reveal geometric relevance, let alone the optimization of them. This paper aims to develop a good image based surrogate relevance criterion to best reflect the underlying inaccessible geometric relevance in a learning context. We cast this surrogate learning problem into an optimization framework, by encouraging the image based surrogate to behave consistently with geometric relevance during training. In particular, we desire a criterion to be small for image pairs with similar geometry and large for those with significantly different segmentation geometry. Validation experiments on corpus callosum segmentation demonstrate the improved quality of the learned surrogate compared to benchmark surrogate candidates.

  19. Numerical Surrogates for Human Observers in Myocardial Motion Evaluation From SPECT Images.

    Science.gov (United States)

    Marin, Thibault; Kalayeh, Mahdi M; Parages, Felipe M; Brankov, Jovan G

    2014-01-01

    In medical imaging, the gold standard for image-quality assessment is a task-based approach in which one evaluates human observer performance for a given diagnostic task (e.g., detection of a myocardial perfusion or motion defect). To facilitate practical task-based image-quality assessment, model observers are needed as approximate surrogates for human observers. In cardiac-gated SPECT imaging, diagnosis relies on evaluation of the myocardial motion as well as perfusion. Model observers for the perfusion-defect detection task have been studied previously, but little effort has been devoted toward development of a model observer for cardiac-motion defect detection. In this work, we describe two model observers for predicting human observer performance in detection of cardiac-motion defects. Both proposed methods rely on motion features extracted using previously reported deformable mesh model for myocardium motion estimation. The first method is based on a Hotelling linear discriminant that is similar in concept to that used commonly for perfusion-defect detection. In the second method, based on relevance vector machines (RVM) for regression, we compute average human observer performance by first directly predicting individual human observer scores, and then using multi reader receiver operating characteristic analysis. Our results suggest that the proposed RVM model observer can predict human observer performance accurately, while the new Hotelling motion-defect detector is somewhat less effective.

  20. Supervised Remote Robot with Guided Autonomy and Teleoperation (SURROGATE): A Framework for Whole-Body Manipulation

    Science.gov (United States)

    Hebert, Paul; Ma, Jeremy; Borders, James; Aydemir, Alper; Bajracharya, Max; Hudson, Nicolas; Shankar, Krishna; Karumanchi, Sisir; Douillard, Bertrand; Burdick, Joel

    2015-01-01

    The use of the cognitive capabilties of humans to help guide the autonomy of robotics platforms in what is typically called "supervised-autonomy" is becoming more commonplace in robotics research. The work discussed in this paper presents an approach to a human-in-the-loop mode of robot operation that integrates high level human cognition and commanding with the intelligence and processing power of autonomous systems. Our framework for a "Supervised Remote Robot with Guided Autonomy and Teleoperation" (SURROGATE) is demonstrated on a robotic platform consisting of a pan-tilt perception head, two 7-DOF arms connected by a single 7-DOF torso, mounted on a tracked-wheel base. We present an architecture that allows high-level supervisory commands and intents to be specified by a user that are then interpreted by the robotic system to perform whole body manipulation tasks autonomously. We use a concept of "behaviors" to chain together sequences of "actions" for the robot to perform which is then executed real time.

  1. Flame ignition studies of conventional and alternative jet fuels and surrogate components

    Science.gov (United States)

    Liu, Ning

    Practical jet fuels are widely used in air-breathing propulsion, but the chemical mechanisms that control their combustion are not yet understood. Thousands of components are contained in conventional and alternative jet fuels, making thus any effort to model their combustion behavior a daunting task. That has been the motivation behind the development of surrogate fuels that contain typically a small number of neat components, whose physical properties and combustion behavior mimic those of the real jet fuel, and whose kinetics could be modeled with increased degree of confidence. Towards that end, a large number of experimental data are required both for the real fuels and the attendant surrogate components that could be used to develop and validate detailed kinetic models. Those kinetic models could be used then upon reduction to model a combustor and eventually optimize its performance. Among all flame phenomena, ignition is rather sensitive to the oxidative and pyrolytic propensity of the fuel as well as to its diffusivity. The counterflow configuration is ideal in probing both the fuel reactivity and diffusivity aspects of the ignition process and it was used in the present work to determine the ignition temperatures of premixed and non-premixed flames of a variety of fuels relevant to air-breathing propulsion. The experiments were performed at atmospheric pressure, elevated unburned fuel mixture temperatures, and various strain rates that were measured locally. Several recent kinetic models were used in direct numerical simulations of the experiments and the computed results were tested against the experimental data. Furthermore, through sensitivity, reaction path, and structure analyses of the computed flames, insight was provided into the dominant mechanisms that control ignition. It was found that ignition is primarily sensitive to fuel diffusion and secondarily sensitive to chemical kinetics and intermediate species diffusivities under the low fuel

  2. Concept theory

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2009-01-01

      Concept theory is an extremely broad, interdisciplinary and complex field of research related to many deep fields with very long historical traditions without much consensus. However, information science and knowledge organization cannot avoid relating to theories of concepts. Knowledge...... organizing systems (e.g. classification systems, thesauri and ontologies) should be understood as systems basically organizing concepts and their semantic relations. The same is the case with information retrieval systems. Different theories of concepts have different implications for how to construe......, evaluate and use such systems. Based on "a post-Kuhnian view" of paradigms this paper put forward arguments that the best understanding and classification of theories of concepts is to view and classify them in accordance with epistemological theories (empiricism, rationalism, historicism and pragmatism...

  3. Definitions and validation criteria for biomarkers and surrogate endpoints: development and testing of a quantitative hierarchical levels of evidence schema

    DEFF Research Database (Denmark)

    Lassere, Marissa N; Johnson, Kent R; Boers, Maarten

    2007-01-01

    of the National Institutes of Health definitions of biomarker, surrogate endpoint, and clinical endpoint was useful. CONCLUSION: Further development and application of this schema provides incentives and guidance for effective biomarker and surrogate endpoint research, and more efficient drug discovery...... endpoints, and leading indicators, a quantitative surrogate validation schema was developed and subsequently evaluated at a stakeholder workshop. RESULTS: The search identified several classification schema and definitions. Components of these were incorporated into a new quantitative surrogate validation...

  4. Pig and guinea pig skin as surrogates for human in vitro penetration studies: a quantitative review.

    Science.gov (United States)

    Barbero, Ana M; Frasch, H Frederick

    2009-02-01

    Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (Pskin permeability of 21% for pig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n=41). The lag times of pig skin and human skin did not correlate (r=0.35, P=0.26). When the in vitro permeability of guinea pig and human skin were compared, r=0.96 (Phuman, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n=15). Lag times of guinea pig and human skin correlated (r=0.90, Phuman skin was calculated for pig skin (n=50) and guinea pig skin (n=25). For pig skin, 80% of measurements fell within the range 0.3skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.

  5. Facial recognition of heroin vaccine opiates: type 1 cross-reactivities of antibodies induced by hydrolytically stable haptenic surrogates of heroin, 6-acetylmorphine, and morphine.

    Science.gov (United States)

    Matyas, Gary R; Rice, Kenner C; Cheng, Kejun; Li, Fuying; Antoline, Joshua F G; Iyer, Malliga R; Jacobson, Arthur E; Mayorov, Alexander V; Beck, Zoltan; Torres, Oscar B; Alving, Carl R

    2014-03-14

    Novel synthetic compounds similar to heroin and its major active metabolites, 6-acetylmorphine and morphine, were examined as potential surrogate haptens for the ability to interface with the immune system for a heroin vaccine. Recent studies have suggested that heroin-like haptens must degrade hydrolytically to induce independent immune responses both to heroin and to the metabolites, resulting in antisera containing mixtures of antibodies (type 2 cross-reactivity). To test this concept, two unique hydrolytically stable haptens were created based on presumed structural facial similarities to heroin or to its active metabolites. After conjugation of a heroin-like hapten (DiAmHap) to tetanus toxoid and mixing with liposomes containing monophosphoryl lipid A, high titers of antibodies after two injections in mice had complementary binding sites that exhibited strong type 1 ("true") specific cross-reactivity with heroin and with both of its physiologically active metabolites. Mice immunized with each surrogate hapten exhibited reduced antinociceptive effects caused by injection of heroin. This approach obviates the need to create hydrolytically unstable synthetic heroin-like compounds to induce independent immune responses to heroin and its active metabolites for vaccine development. Facial recognition of hydrolytically stable surrogate haptens by antibodies together with type 1 cross-reactivities with heroin and its metabolites can help to guide synthetic chemical strategies for efficient development of a heroin vaccine.

  6. Laboratory Testing of Waste Isolation Pilot Plant Surrogate Waste Materials

    Science.gov (United States)

    Broome, S.; Bronowski, D.; Pfeifle, T.; Herrick, C. G.

    2011-12-01

    The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy geological repository for the permanent disposal of defense-related transuranic (TRU) waste. The waste is emplaced in rooms excavated in the bedded Salado salt formation at a depth of 655 m below the ground surface. After emplacement of the waste, the repository will be sealed and decommissioned. WIPP Performance Assessment modeling of the underground material response requires a full and accurate understanding of coupled mechanical, hydrological, and geochemical processes and how they evolve with time. This study was part of a broader test program focused on room closure, specifically the compaction behavior of waste and the constitutive relations to model this behavior. The goal of this study was to develop an improved waste constitutive model. The model parameters are developed based on a well designed set of test data. The constitutive model will then be used to realistically model evolution of the underground and to better understand the impacts on repository performance. The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of the degraded containers and TRU waste materials after the 10,000 year regulatory period. Testing consists of hydrostatic, uniaxial, and triaxial tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, and rubbers. Axial, lateral, and volumetric strain and axial and lateral stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk

  7. Chemical kinetic study of the oxidation of a biodiesel-bioethanol surrogate fuel: methyl octanoate-ethanol mixtures.

    Science.gov (United States)

    Togbé, C; May-Carle, J-B; Dayma, G; Dagaut, P

    2010-03-25

    There is a growing interest for using bioethanol-biodiesel fuel blends in diesel engines but no kinetic data and model for their combustion were available. Therefore, the kinetics of oxidation of a biodiesel-bioethanol surrogate fuel (methyl octanoate-ethanol) was studied experimentally in a jet-stirred reactor at 10 atm and constant residence time, over the temperature range 560-1160 K, and for several equivalence ratios (0.5-2). Concentration profiles of reactants, stable intermediates, and final products were obtained by probe sampling followed by online FTIR, and off-line gas chromatography analyses. The oxidation of this fuel in these conditions was modeled using a detailed chemical kinetic reaction mechanism consisting of 4592 reversible reactions and 1087 species. The proposed kinetic reaction mechanism yielded a good representation of the kinetics of oxidation of this biodiesel-bioethanol surrogate under the JSR conditions. The modeling was used to delineate the reactions triggering the low-temperature oxidation of ethanol important for diesel engine applications.

  8. A general framework to learn surrogate relevance criterion for atlas based image segmentation

    Science.gov (United States)

    Zhao, Tingting; Ruan, Dan

    2016-09-01

    Multi-atlas based image segmentation sees great opportunities in the big data era but also faces unprecedented challenges in identifying positive contributors from extensive heterogeneous data. To assess data relevance, image similarity criteria based on various image features widely serve as surrogates for the inaccessible geometric agreement criteria. This paper proposes a general framework to learn image based surrogate relevance criteria to better mimic the behaviors of segmentation based oracle geometric relevance. The validity of its general rationale is verified in the specific context of fusion set selection for image segmentation. More specifically, we first present a unified formulation for surrogate relevance criteria and model the neighborhood relationship among atlases based on the oracle relevance knowledge. Surrogates are then trained to be small for geometrically relevant neighbors and large for irrelevant remotes to the given targets. The proposed surrogate learning framework is verified in corpus callosum segmentation. The learned surrogates demonstrate superiority in inferring the underlying oracle value and selecting relevant fusion set, compared to benchmark surrogates.

  9. Surrogate mobility and orientation affect the early neurobehavioral development of infant rhesus macaques (Macaca mulatta).

    Science.gov (United States)

    Dettmer, Amanda M; Ruggiero, Angela M; Novak, Melinda A; Meyer, Jerrold S; Suomi, Stephen J

    2008-05-01

    A biological mother's movement appears necessary for optimal development in infant monkeys. However, nursery-reared monkeys are typically provided with inanimate surrogate mothers that move very little. The purpose of this study was to evaluate the effects of a novel, highly mobile surrogate mother on motor development, exploration, and reactions to novelty. Six infant rhesus macaques (Macaca mulatta) were reared on mobile hanging surrogates (MS) and compared to six infants reared on standard stationary rocking surrogates (RS) and to 9-15 infants reared with their biological mothers (MR) for early developmental outcome. We predicted that MS infants would develop more similarly to MR infants than RS infants. In neonatal assessments conducted at Day 30, both MS and MR infants showed more highly developed motor activity than RS infants on measures of grasping (p = .009), coordination (p = .038), spontaneous crawl (p = .009), and balance (p = .003). At 2-3 months of age, both MS and MR infants displayed higher levels of exploration in the home cage than RS infants (p = .016). In a novel situation in which only MS and RS infants were tested, MS infants spent less time near their surrogates in the first five minutes of the test session than RS infants (p = .05), indicating a higher level of comfort. Collectively, these results suggest that when nursery-rearing of infant monkeys is necessary, a mobile hanging surrogate may encourage more normative development of gross motor skills and exploratory behavior and may serve as a useful alternative to stationary or rocking surrogates.

  10. A general framework to learn surrogate relevance criterion for atlas based image segmentation.

    Science.gov (United States)

    Zhao, Tingting; Ruan, Dan

    2016-09-07

    Multi-atlas based image segmentation sees great opportunities in the big data era but also faces unprecedented challenges in identifying positive contributors from extensive heterogeneous data. To assess data relevance, image similarity criteria based on various image features widely serve as surrogates for the inaccessible geometric agreement criteria. This paper proposes a general framework to learn image based surrogate relevance criteria to better mimic the behaviors of segmentation based oracle geometric relevance. The validity of its general rationale is verified in the specific context of fusion set selection for image segmentation. More specifically, we first present a unified formulation for surrogate relevance criteria and model the neighborhood relationship among atlases based on the oracle relevance knowledge. Surrogates are then trained to be small for geometrically relevant neighbors and large for irrelevant remotes to the given targets. The proposed surrogate learning framework is verified in corpus callosum segmentation. The learned surrogates demonstrate superiority in inferring the underlying oracle value and selecting relevant fusion set, compared to benchmark surrogates.

  11. Travelling Concepts

    DEFF Research Database (Denmark)

    Simonsen, Karen-Margrethe

    2013-01-01

    Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012......Review of "Travelling Concepts, Metaphors, and Narratives: Literary and Cultural Studies in an Age of Interdisciplinary Research" ed. by Sibylle Baumgarten, Beatrice Michaelis and Ansagar Nünning, Trier; Wissenschaftlicher Verlag Trier, 2012...

  12. A Multi-Fidelity Surrogate Model for Handling Real Gas Equations of State

    Science.gov (United States)

    Ouellet, Frederick; Park, Chanyoung; Rollin, Bertrand; Balachandar, S."bala"

    2016-11-01

    The explosive dispersal of particles is an example of a complex multiphase and multi-species fluid flow problem. This problem has many engineering applications including particle-laden explosives. In these flows, the detonation products of the explosive cannot be treated as a perfect gas so a real gas equation of state is used to close the governing equations (unlike air, which uses the ideal gas equation for closure). As the products expand outward from the detonation point, they mix with ambient air and create a mixing region where both of the state equations must be satisfied. One of the more accurate, yet computationally expensive, methods to deal with this is a scheme that iterates between the two equations of state until pressure and thermal equilibrium are achieved inside of each computational cell. This work strives to create a multi-fidelity surrogate model of this process. We then study the performance of the model with respect to the iterative method by performing both gas-only and particle laden flow simulations using an Eulerian-Lagrangian approach with a finite volume code. Specifically, the model's (i) computational speed, (ii) memory requirements and (iii) computational accuracy are analyzed to show the benefits of this novel modeling approach. This work was supported by the U.S. Department of Energy, National Nuclear Security Administration, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA00023.

  13. Application of a framework for extrapolating chemical effects across species in pathways controlled by estrogen receptor-á

    Science.gov (United States)

    Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetic...

  14. Results from Second Round of Remediated Nitrate Salt Surrogate Formulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Geoffrey Wayne [Los Alamos National Laboratory; Leonard, Philip [Los Alamos National Laboratory; Hartline, Ernest Leon [Los Alamos National Laboratory; Tian, Hongzhao [Los Alamos National Laboratory

    2016-04-04

    High Explosives and Technology (M-7) completed the second round of formulation and testing of Remediated Nitrate Salt (RNS) surrogates on March 17, 2016. This report summarizes the results of the work and also includes additional documentation required under test plan PLAN-TA9-2443 Rev B, "Remediated Nitrate Salt (RNS) Surrogate Formulation and Testing Standard Procedure", released February 16, 2016. All formulation and testing was carried out according to PLAN-TA9-2443 Rev B. Results from the first round of formulation and testing were documented in memorandum M7-16-6042, "Results from First Round of Remediated Nitrate Salt Surrogate Formulation and Testing."

  15. Assessing the potential of surrogate EPS to mimic natural biofilm mechanical properties

    Science.gov (United States)

    Thom, Moritz; Schimmels, Stefan

    2017-04-01

    Biofilms growing on benthic sediments may increase the resistance towards erosion considerably by the sticky nature of extracellular polymeric substances (EPS). The EPS is a biopolymer which is secreted by the microorganisms inhabiting the biofilm matrix and may be regarded as natural glue. However, laboratory studies on the biostabilization effect mediated by biofilms are often hampered by the unavailability of "environmental" flumes in which light intensities, water temperature and nutrient content can be controlled. To allow investigations on biostabilization in "traditional" flume settings the use of surrogate materials is studied. Another advantage of using appropriate surrogates is the potential to reduce the experimental time, as compared to cultivating natural biofilms, the surrogates can readily be designed to mimic biofilms at different growth stages. Furthermore, the use of surrogates which are expected to have more homogeneous mechanical properties could facilitate fundamental studies to improve our knowledge on biostabilization. Even though a number of studies have already utilized EPS surrogates it is not clear how to mix them to correctly mimic natural EPS mechanical properties. In this study the adhesiveness (a measure of stickiness) on the surface of several EPS surrogates (e.g. Xanthan Gum, sodium alginate) is measured. These surrogates which are originally used in the food industry as rheology modifiers are mixed by adding water to a powder at a desired concentration (C). The measured surface adhesion of different surrogates at different concentrations ranged from 0.5 to 6.7 N/m2, which is well in line with values found for laboratory cultured biofilms. We found that the surrogate characteristics differed largely especially in regard to a) the response of the adhesiveness to increased concentrations (powder to water) and b) in their rheological characteristics. A seemingly promising surrogate for the use in biostabilization studies is Xanthan Gum

  16. Children of surrogate mothers: psychological well-being, family relationships and experiences of surrogacy.

    Science.gov (United States)

    Jadva, V; Imrie, S

    2014-01-01

    What impact does surrogacy have on the surrogates' own children? The children of surrogate mothers do not experience any negative consequences as a result of their mother's decision to be a surrogate, irrespective of whether or not the surrogate uses her own egg. Participants were recruited as part of a study of the long-term effects of surrogacy for surrogates and their family members. Data were collected from 36 children of surrogates at a single time point. Participants whose mother had been a surrogate 5-15 years prior to interview and who were aged over 12 years were eligible to take part. Thirty-six participants (14 male and 22 female) aged 12-25 years were interviewed (response rate = 52%). Questionnaires assessing psychological health and family functioning were administered. Forty-four per cent (15) of participants' mothers had undergone gestational surrogacy, 39% (14) had used their own egg (genetic surrogacy) and 19% (7) had completed both types of surrogacy. Most surrogates' children (86%, 31) had a positive view of their mother's surrogacy. Forty-seven per cent (17) of children were in contact with the surrogacy child and all reported good relationships with him/her. Forty per cent (14) of children referred to the child as a sibling or half-sibling and this did not differ between genetic and gestational surrogacy. Most children (89%, 32), reported a positive view of family life, with all enjoying spending time with their mother. Mean scores on the questionnaire assessments of psychological health and self-esteem were within the normal range and did not differ by surrogacy type. The sample size for this study was relatively small and not all children chose to take part, therefore their views cannot be known. Nevertheless, this is the first study to assess the experiences of surrogacy from the perspective of the surrogates' own children. There may be some bias from the inclusion of siblings from the same family. Findings of this study show that family

  17. Efficient Calibration of Computationally Intensive Groundwater Models through Surrogate Modelling with Lower Levels of Fidelity

    Science.gov (United States)

    Razavi, S.; Anderson, D.; Martin, P.; MacMillan, G.; Tolson, B.; Gabriel, C.; Zhang, B.

    2012-12-01

    Many sophisticated groundwater models tend to be computationally intensive as they rigorously represent detailed scientific knowledge about the groundwater systems. Calibration (model inversion), which is a vital step of groundwater model development, can require hundreds or thousands of model evaluations (runs) for different sets of parameters and as such demand prohibitively large computational time and resources. One common strategy to circumvent this computational burden is surrogate modelling which is concerned with developing and utilizing fast-to-run surrogates of the original computationally intensive models (also called fine models). Surrogates can be either based on statistical and data-driven models such as kriging and neural networks or simplified physically-based models with lower fidelity to the original system (also called coarse models). Fidelity in this context refers to the degree of the realism of a simulation model. This research initially investigates different strategies for developing lower-fidelity surrogates of a fine groundwater model and their combinations. These strategies include coarsening the fine model, relaxing the numerical convergence criteria, and simplifying the model geological conceptualisation. Trade-offs between model efficiency and fidelity (accuracy) are of special interest. A methodological framework is developed for coordinating the original fine model with its lower-fidelity surrogates with the objective of efficiently calibrating the parameters of the original model. This framework is capable of mapping the original model parameters to the corresponding surrogate model parameters and also mapping the surrogate model response for the given parameters to the original model response. This framework is general in that it can be used with different optimization and/or uncertainty analysis techniques available for groundwater model calibration and parameter/predictive uncertainty assessment. A real-world computationally

  18. Heterogeneous Reactions of Surface-Adsorbed Catechol: A Comparison of Tropospheric Aerosol Surrogates

    Science.gov (United States)

    Hinrichs, R. Z.; Woodill, L. A.

    2009-12-01

    Surface-adsorbed organics can alter the chemistry of tropospheric solid-air interfaces, such as aerosol and ground level surfaces, thereby impacting photochemical cycles and altering aerosol properties. The nature of the surface can also influence the chemistry of the surface-adsorbed organic. We employed diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to monitor the adsorption of gaseous catechol on several tropospheric aerosol surrogates and to investigate the subsequent reactivity of adsorbed-catechol with nitrogen dioxide and, in separate preliminary experiments, ozone. Graphite, kaolinite, and sodium halide (NaF, NaCl, NaBr) powders served as carbonaceous, mineral and sea salt aerosol surrogates, respectively. Broad OH stretching bands for adsorbed catechol shifted to lower wavenumber with peak frequencies following the trend NaBr > NaCl > NaF ≈ kaolinite, consistent with the increasing basicity of the halide anions and basic Brønsted sites on kaolinite. The dark heterogeneous reaction of NO2 with NaCl-adsorbed catechol at relative humidity (RH) 4-nitrocatechol and oxidation forming 1,2-benzoquinone and the ring cleavage product muconic acid, with product yields of 88%, 8%, and 4%, respectively. 4-Nitrocatechol was the dominant product for catechol adsorbed on NaF and kaolinite, while NaBr-adsorbed catechol produced less 4-nitrocatechol and more 1,2-benzoquinone and muconic acid. For all three sodium halides, the reactions of NO2 with adsorbed catechol were orders of magnitude faster than between NO2 and each NaX substrate. 4-Nitrocatechol rates and product yields were consistent with the relative ability of each substrate to enhance the deprotonated nature of adsorbed-catechol. Increasing the relative humidity caused the rate of each product channel to decrease and also altered the product branching ratios. Most notably, 1,2-benzoquinone formation decreased significantly even at 13% RH. The dramatic reactivity of surface

  19. Numerical investigation for erratic behavior of Kriging surrogate model

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Gil; Yi, Seul Gi [KAIST, Daejeon (Korea, Republic of); Choi, Seong Im [Virginia Polytechnic Institute and State University, Blacksburg (United States)

    2014-09-15

    Kriging model is one of popular spatial/temporal interpolation models in engineering field since it could reduce the time resources for the expensive analysis. But generation of the Kriging model is hardly a sinecure because internal semi-variogram structure of the Kriging often reveals numerically unstable or erratic behaviors. In present study, the issues in the maximum likelihood estimation which are the vital-parts of the construction of the Kriging model, is investigated. These issues are divided into two aspects; Issue I is for the erratic response of likelihood function itself, and Issue II is for numerically unstable behaviors in the correlation matrix. For both issues, studies for specific circumstances which might raise the issue, and the reason of that are conducted. Some practical ways further are suggested to cope with them. Furthermore, the issue is studied for practical problem; aerodynamic performance coefficients of two-dimensional airfoil predicted by CFD analysis. Result shows that such erratic behavior of Kriging surrogate model can be effectively resolved by proposed solution. In conclusion, it is expected this paper could be helpful to prevent such an erratic and unstable behavior.

  20. Protected Gold Nanoparticles with Thioethers and Amines As Surrogate Ligands

    Directory of Open Access Journals (Sweden)

    M. Rafiq H. Siddiqui

    2013-01-01

    Full Text Available Dodecyl sulfide, dodecyl amine, and hexylamine were shown to act as surrogate ligands (L via metastable gold nanoparticles. By collating analytical and spectroscopic data obtained simultaneously, empirical formula Au24L was assigned. These impurity-free nanoparticles obtained in near quantitative yields showing exceptional gold assays (up to 98%Au were prepared by a modification of the two-phase method. Replacement reactions on the Au24L showed that Au:L ratios may be increased (up to Au55:L (L= (H25C122S or decreased (Au12:L (L= H2NC12H25 and H2NC6H13 as desired. This work encompassing the role of analytical techniques used, that is, elemental analysis, variable temperature 1H NMR, FAB mass spectrometry, UV-Vis spectroscopy, thin film X-ray diffraction, and high-resolution electron microscopy (HREM has implications in the study of size control, purity, stability, and metal assays of gold nanoparticles.

  1. Investigation of ethosomes as surrogate carriers for bioactives

    Directory of Open Access Journals (Sweden)

    Devina Verma

    2016-01-01

    Full Text Available Background: Ethosomal vesicular system delivering a bioactive phytochemical, chrysin, was developed for transdermal delivery to increase its permeability and penetrability. Materials and Methods: Ethosomal system was optimized by keeping lecithin and ethanol concentration as independent variable while size and size distribution were taken as dependent variables. The optimized formulation was then subjected to various in vitro characterization parameters. Results: Ethosomal vesicle with an optimum size and polydispersity index of 134 ± 35 nm and 0.153, respectively, and entrapment efficiency of 80.05 ± 2.6% was considered as optimized and subjected to characterization. The scanning electron microscopy and transmission electron microscopy showed spherical entities with uniform surface whereas in vitro permeation and retention study showed the sustained mode of drug release and better skin retention as compared to hydroethanolic solution of the drug. The confocal laser scanning microscopy study reiterated high penetrability of vesicles into the skin. Histopathological and Fourier transform infrared spectroscopy analysis revealed its mechanism of penetration. Conclusion : The study thus demonstrated the ability of the ethosomal vesicles as surrogate carriers for delivery of bioactive agents through the skin for better amelioration of skin inflammation and other diseases.

  2. Characterization of Air Plane Soot Surrogates using Raman spectroscopy and laser ablation techniques

    Science.gov (United States)

    Chazallon, Bertrand; Ortega, Ismael Kenneth; Ikhenazene, Raouf; Pirim, Claire; Carpentier, Yvain; Irimiea, Cornelia; Focsa, Cristian; Ouf, François-Xavier

    2016-04-01

    Aviation alters the composition of the atmosphere globally and can thus drive climate change and ozone depletion [1]. Aircraft exhaust plumes contain species (gases and soot particles) produced by the combustion of kerosene with ambient air in the combustion chamber of the engine. Soot particles emitted by air-planes produce persistent contrails in the upper troposphere in ice-supersaturated air masses that contribute to cloudiness and impact the radiative properties of the atmosphere. These aerosol-cloud interactions represent one of the largest sources of uncertainty in global climate models [2]. Though the formation of atmospheric ice particles has been studied for many years [3], there are still numerous opened questions on nucleation properties of soot particles [4], as the ice nucleation experiments showed a large spread in results depending on the nucleation mode chosen and origin of the soot produced. The reasons behind these discrepancies reside in the different physico-chemical properties (composition, structure) of soot particles produced in different conditions, e.g., with respect to fuel or combustion techniques. In this work, we use Raman microscopy (514 and 785 nm excitation wavelengths) and ablation techniques (Secondary Ions Mass Spectrometry, and Laser Desorption Mass Spectrometry) to characterize soot particle surrogates produced from a CAST generator (propane fuel, four different global equivalence ratios). They are produced as analogues of air-plane soot collected at different engine regimes (PowerJet SaM-146 turbofan) simulating a landing and take-off (LTO) cycle (MERMOSE project (http://mermose.onera.fr/)) [6]. The spectral parameters of the first-order Raman bands of these soot samples are analyzed using a de-convolution approach described by Sadezky et al. (2005) [5]. A systematic Raman analysis is carried out to select a number of parameters (laser wavelength, irradiance at sample, exposure time) that will alter the sample and the

  3. Lateral Concepts

    Directory of Open Access Journals (Sweden)

    Christopher Gad

    2016-06-01

    Full Text Available This essay discusses the complex relation between the knowledges and practices of the researcher and his/her informants in terms of lateral concepts. The starting point is that it is not the prerogative of the (STS scholar to conceptualize the world; all our “informants” do it too. This creates the possibility of enriching our own conceptual repertoires by letting them be inflected by the concepts of those we study. In a broad sense, the lateral means that there is a many-to-many relation between domains of knowledge and practice. However, each specific case of the lateral is necessarily immanent to a particular empirical setting and form of inquiry. In this sense lateral concepts are radically empirical since it locates concepts within the field. To clarify the meaning and stakes of lateral concepts, we first make a contrast between lateral anthropology and Latour’s notion of infra-reflexivity. We end with a brief illustration and discussion of how lateral conceptualization can re-orient STS modes of inquiry, and why this matters.

  4. Restrictive concept of surrogacy in the draft text of the Civil Code of Serbia

    Directory of Open Access Journals (Sweden)

    Bordaš Bernadet I.

    2015-01-01

    Full Text Available The working draft of the Civil Code of Serbia, which was published in June 2015, includes model-provisions on surrogate motherhood, which is, at present, expressly prohibited by law. The paper gives a survey of the proposed provisions and examines particularly those that define which persons can conclude a contract on surrogacy. By limiting this right to persons holding the nationality of Serbia, or to these nationals and persons residing in the territory of Serbia for at least three (five years the legislator wish to avoid reproductive tourism. Surrogate mothering with cross-border effects gives rise to complicated legal problems as regards the definition and recognition of legal parentage of the intended parents both in the countries in which the surrogate mother gives birth to the child, as well as in countries in which the intended parents wish to live with their child. The restrictive concept which retains surrogate mothering within the borders of the domestic state and between domestic nationals disables outgoing cases of surrogate motherhood, but it is not quite true for persons who are not citizens of Serbia, but living on its territory. For these reasons the paper critically examines these limitations in the proposals, and indicates that the incoming cases of surrogate motherhood cannot be prevented due to the free movement of people. The paper also provides analysis of the legal issues of the incoming cases of surrogate motherhood, and suggests solution for them if in the future Civil Code the proposed ipso jure legal parenthood of intended parents will be adopted. With ipso jure legal parenthood of a child who is born to a surrogate mother abroad there is no need to restrict surrogacy cases to nationals of Serbia or to foreigners domiciled in Serbia for three (five years minimum.

  5. Effective NOx remediation from a surrogate flue gas using the US NRL Electra electron beam facility

    Science.gov (United States)

    Petrova, Tz. B.; Petrov, G. M.; Wolford, M. F.; Giuliani, J. L.; Ladouceur, H. D.; Hegeler, F.; Myers, M. C.; Sethian, J. D.

    2017-02-01

    Nitric oxide (NOx) emission is under restrictive federal regulations because of its negative impact on atmosphere, biosphere, and human health. Therefore, its removal has been a subject of extensive research to develop new efficient and cost effective techniques that can be applied on an industrial scale. In this work, we study both experimentally and theoretically an effective removal of NOx pollutants from a surrogate flue gas (SFG) using high power electron beam (e-beam) pulses. SFG is a simulant for exhaust from coal combustion power plants (82% N2, 6% O2, 12% CO2, and ˜100 ppm of NOx). The pulsed electron beam is generated using the United States Naval Research Laboratory Electra facility, which delivers e-beams with energies of ˜500 keV and a power pulse duration of ˜140 ns. During the e-beam irradiation, the energetic electrons generate a non-equilibrium plasma containing chemically active species, which then react with NOx to form harmless substances. A non-equilibrium time-dependent model is developed to describe NOx remediation from SFG. The model combines e-beam deposition rates obtained by solving the electron Boltzmann equation and extensive plasma chemistry modeling, which follows the species on a time scale from sub-nanoseconds to a few seconds. NOx decomposition as a function of electron beam parameters is studied. It is demonstrated experimentally that short (ns) pulses are the most efficient for NOx removal. A sharp reduction of NOx was measured with e-beam power deposition increasing, following the trend predicted by the model, achieving a 20 fold reduction to ˜5 ppm at energy deposition ˜20 J/l.

  6. Surrogate Models for Online Monitoring and Process Troubleshooting of NBR Emulsion Copolymerization

    Directory of Open Access Journals (Sweden)

    Chandra Mouli R. Madhuranthakam

    2016-03-01

    Full Text Available Chemical processes with complex reaction mechanisms generally lead to dynamic models which, while beneficial for predicting and capturing the detailed process behavior, are not readily amenable for direct use in online applications related to process operation, optimisation, control, and troubleshooting. Surrogate models can help overcome this problem. In this research article, the first part focuses on obtaining surrogate models for emulsion copolymerization of nitrile butadiene rubber (NBR, which is usually produced in a train of continuous stirred tank reactors. The predictions and/or profiles for several performance characteristics such as conversion, number of polymer particles, copolymer composition, and weight-average molecular weight, obtained using surrogate models are compared with those obtained using the detailed mechanistic model. In the second part of this article, optimal flow profiles based on dynamic optimisation using the surrogate models are obtained for the production of NBR emulsions with the objective of minimising the off-specification product generated during grade transitions.

  7. An Efficient Constraint Boundary Sampling Method for Sequential RBDO Using Kriging Surrogate Model

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jihoon; Jang, Junyong; Kim, Shinyu; Lee, Tae Hee [Hanyang Univ., Seoul (Korea, Republic of); Cho, Sugil; Kim, Hyung Woo; Hong, Sup [Korea Research Institute of Ships and Ocean Engineering, Busan (Korea, Republic of)

    2016-06-15

    Reliability-based design optimization (RBDO) requires a high computational cost owing to its reliability analysis. A surrogate model is introduced to reduce the computational cost in RBDO. The accuracy of the reliability depends on the accuracy of the surrogate model of constraint boundaries in the surrogated-model-based RBDO. In earlier researches, constraint boundary sampling (CBS) was proposed to approximate accurately the boundaries of constraints by locating sample points on the boundaries of constraints. However, because CBS uses sample points on all constraint boundaries, it creates superfluous sample points. In this paper, efficient constraint boundary sampling (ECBS) is proposed to enhance the efficiency of CBS. ECBS uses the statistical information of a kriging surrogate model to locate sample points on or near the RBDO solution. The efficiency of ECBS is verified by mathematical examples.

  8. Endospore surface properties of commonly used Bacillus anthracis surrogates vary in aqueous solution

    Science.gov (United States)

    The hydrophobic character and electrophoretic mobility of microorganisms are vital aspects of understanding their interactions with the environment. These properties are fundamental in fate-and-transport, physiological, and virulence studies, and thus integral in surrogate select...

  9. Trimethylsilylethynyl ketones as surrogates for ethynyl ketones in the double Michael reaction.

    Science.gov (United States)

    Holeman, Derrick S; Rasne, Ravindra M; Grossman, Robert B

    2002-05-01

    Trimethylsilylethynyl ketones can be desilylated in the presence of a tethered carbon diacid and induced to undergo a double Michael reaction in situ. The trimethylsilylethynyl ketones can serve as surrogates of ethynyl ketones that are difficult to prepare or isolate.

  10. Significance of Including a Surrogate Arousal for Sleep Apnea-Hypopnea Syndrome Diagnosis by Respiratory Polygraphy

    Science.gov (United States)

    Masa, Juan F.; Corral, Jaime; Gomez de Terreros, Javier; Duran-Cantolla, Joaquin; Cabello, Marta; Hernández-Blasco, Luis; Monasterio, Carmen; Alonso, Alberto; Chiner, Eusebi; Aizpuru, Felipe; Zamorano, Jose; Cano, Ricardo; Montserrat, Jose M.; Garcia-Ledesma, Estefania; Pereira, Ricardo; Cancelo, Laura; Martinez, Angeles; Sacristan, Lirios; Salord, Neus; Carrera, Miguel; Sancho-Chust, José N.; Embid, Cristina

    2013-01-01

    Rationale: Respiratory polygraphy is an accepted alternative to polysomnography (PSG) for sleep apnea/hypopnea syndrome (SAHS) diagnosis, although it underestimates the apnea-hypopnea index (AHI) because respiratory polygraphy cannot identify arousals. Objectives: We performed a multicentric, randomized, blinded crossover study to determine the agreement between home respiratory polygraphy (HRP) and PSG, and between simultaneous respiratory polygraphy (respiratory polygraphy with PSG) (SimultRP) and PSG by means of 2 AHI scoring protocols with or without hyperventilation following flow reduction considered as a surrogate arousal. Methods: We included suspected SAHS patients from 8 hospitals. They were assigned to home and hospital protocols at random. We determined the agreement between respiratory polygraphy AHI and PSG AHI scorings using Bland and Altman plots and diagnostic agreement using receiver operating characteristic (ROC) curves. The agreement in therapeutic decisions (continuous positive airway pressure treatment or not) between HRP and PSG scorings was done with likelihood ratios and post-test probability calculations. Results: Of 366 randomized patients, 342 completed the protocol. AHI from HRP scorings (with and without surrogate arousal) had similar agreement with PSG. AHI from SimultRP with surrogate arousal scoring had better agreement with PSG than AHI from SimultRP without surrogate arousal. HRP with surrogate arousal scoring had slightly worse ROC curves than HRP without surrogate arousal, and the opposite was true for SimultRP scorings. HRP with surrogate arousal showed slightly better agreement with PSG in therapeutic decisions than for HRP without surrogate arousal. Conclusion: Incorporating a surrogate arousal measure into HRP did not substantially increase its agreement with PSG when compared with the usual procedure (HRP without surrogate arousal). Citation: Masa JF; Corral J; Gomez de Terreros J; Duran-Cantolla J; Cabello M; Hern

  11. Surrogate end points in women's health research: science, protoscience, and pseudoscience.

    Science.gov (United States)

    Grimes, David A; Schulz, Kenneth F; Raymond, Elizabeth G

    2010-04-01

    A surrogate end point (e.g., a laboratory test or image) serves as a proxy for a clinical end point of importance (e.g., fracture, thrombosis, or death). Adoption and use of surrogate end points lacking validation, especially in cardiovascular medicine, have caused thousands of patients' deaths, a serious violation of the ethical principle of beneficence. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  12. Desorption of a methamphetamine surrogate from wallboard under remediation conditions

    Science.gov (United States)

    Poppendieck, Dustin; Morrison, Glenn; Corsi, Richard

    2015-04-01

    Thousands of homes in the United States are found to be contaminated with methamphetamine each year. Buildings used to produce illicit methamphetamine are typically remediated by removing soft furnishings and stained materials, cleaning and sometimes encapsulating surfaces using paint. Methamphetamine that has penetrated into paint films, wood and other permanent materials can be slowly released back into the building air over time, exposing future occupants and re-contaminating furnishings. The objective of this study was to determine the efficacy of two wallboard remediation techniques for homes contaminated with methamphetamine: 1) enhancing desorption by elevating temperature and relative humidity while ventilating the interior space, and 2) painting over affected wallboard to seal the methamphetamine in place. The emission of a methamphetamine surrogate, N-isopropylbenzylamine (NIBA), from pre-dosed wallboard chambers over 20 days at 32 °C and two values of relative humidity were studied. Emission rates from wallboard after 15 days at 32 °C ranged from 35 to 1400 μg h-1 m-2. Less than 22% of the NIBA was removed from the chambers over three weeks. Results indicate that elevating temperatures during remediation and latex painting of impacted wallboard will not significantly reduce freebase methamphetamine emissions from wallboard. Raising the relative humidity from 27% to 49% increased the emission rates by a factor of 1.4. A steady-state model of a typical home using the emission rates from this study and typical residential building parameters and conditions shows that adult inhalation reference doses for methamphetamine will be reached when approximately 1 g of methamphetamine is present in the wallboard of a house.

  13. Survival of norovirus surrogate on various food-contact surfaces.

    Science.gov (United States)

    Kim, An-Na; Park, Shin Young; Bae, San-Cheong; Oh, Mi-Hwa; Ha, Sang-Do

    2014-09-01

    Norovirus (NoV) is an environmental threat to humans, which spreads easily from one infected person to another, causing foodborne and waterborne diseases. Therefore, precautions against NoV infection are important in the preparation of food. The aim of this study was to investigate the survival of murine norovirus (MNV), as a NoV surrogate, on six different food-contact surfaces: ceramic, wood, rubber, glass, stainless steel, and plastic. We inoculated 10(5) PFU of MNV onto the six different surface coupons that were then kept at room temperature for 28 days. On the food-contact surfaces, the greatest reduction in MNV was 2.28 log10 PFU/coupon, observed on stainless steel, while the lowest MNV reduction was 1.29 log10 PFU/coupon, observed on wood. The rank order of MNV reduction, from highest to lowest, was stainless steel, plastic, rubber, glass, ceramic, and wood. The values of d R (time required to reduce the virus by 90%) on survival plots of MNV determined by a modified Weibull model were 277.60 h (R(2) = 0.99) on ceramic, 492.59 h (R(2) = 0.98) on wood, 173.56 h on rubber (R(2) = 0.98), 97.18 h (R(2) = 0.94) on glass, 91.76 h (R(2) = 0.97) on stainless steel, and 137.74 h (R(2) = 0.97) on plastic. The infectivity of MNV on all food-contact surfaces remained after 28 days. These results show that MNV persists in an infective state on various food-contact surfaces for long periods. This study may provide valuable information for the control of NoV on various food-contact surfaces, in order to prevent foodborne disease.

  14. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    Directory of Open Access Journals (Sweden)

    Brian France

    Full Text Available Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping and post-decon to determine that the site is free of contamination (clearance sampling. Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation.

  15. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil

    Science.gov (United States)

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation. PMID:26714315

  16. Composite Sampling Approaches for Bacillus anthracis Surrogate Extracted from Soil.

    Science.gov (United States)

    France, Brian; Bell, William; Chang, Emily; Scholten, Trudy

    2015-01-01

    Any release of anthrax spores in the U.S. would require action to decontaminate the site and restore its use and operations as rapidly as possible. The remediation activity would require environmental sampling, both initially to determine the extent of contamination (hazard mapping) and post-decon to determine that the site is free of contamination (clearance sampling). Whether the spore contamination is within a building or outdoors, collecting and analyzing what could be thousands of samples can become the factor that limits the pace of restoring operations. To address this sampling and analysis bottleneck and decrease the time needed to recover from an anthrax contamination event, this study investigates the use of composite sampling. Pooling or compositing of samples is an established technique to reduce the number of analyses required, and its use for anthrax spore sampling has recently been investigated. However, use of composite sampling in an anthrax spore remediation event will require well-documented and accepted methods. In particular, previous composite sampling studies have focused on sampling from hard surfaces; data on soil sampling are required to extend the procedure to outdoor use. Further, we must consider whether combining liquid samples, thus increasing the volume, lowers the sensitivity of detection and produces false negatives. In this study, methods to composite bacterial spore samples from soil are demonstrated. B. subtilis spore suspensions were used as a surrogate for anthrax spores. Two soils (Arizona Test Dust and sterilized potting soil) were contaminated and spore recovery with composites was shown to match individual sample performance. Results show that dilution can be overcome by concentrating bacterial spores using standard filtration methods. This study shows that composite sampling can be a viable method of pooling samples to reduce the number of analysis that must be performed during anthrax spore remediation.

  17. Design, development, and analysis of a surrogate for pulmonary injury prediction.

    Science.gov (United States)

    Danelson, Kerry A; Gayzik, F Scott; Stern, Amber Rath; Hoth, J Jason; Stitzel, Joel D

    2011-10-01

    Current anthropomorphic test devices (ATDs) measure chest acceleration and deflection to assess risk of injury to the thorax. This study presents a lung surrogate prototype designed to expand the injury assessment capabilities of ATDs to include a risk measure for pulmonary contusion (PC). The surrogate augments these existing measures by providing pressure data specific to the lung and its lobes. The prototype was created from a rendering of a 50th percentile male lung inflated to normal inspiration, obtained from clinical CT data. Surrogate size, lobe volume, and airway cross sections were selected to match the morphology of the lung. Elastomeric urethane was molded via rapid prototyping to create a functional prototype. Pressure sensors in each of the five terminal airways independently monitored pressure traces in the lobes during impacts to the surrogate. Software was created to analyze the surrogate impact pressure data, determine the lobe with the greatest pressure rise for a particular impact, and estimate the initial speed of surface deformation. Calibration testing indicates an approximately linear relationship between peak lobe pressure and surface impact speed. No type I or II errors were demonstrated during lobe detection testing. During repeatability testing, the standard deviation was between 2 and 4% of the mean peak pressure. Ongoing research will focus on correlating surrogate data, pressure pulses, or surface deformation, to risk functions for PC.

  18. Adaptive surrogate model based multi-objective transfer trajectory optimization between different libration points

    Science.gov (United States)

    Peng, Haijun; Wang, Wei

    2016-10-01

    An adaptive surrogate model-based multi-objective optimization strategy that combines the benefits of invariant manifolds and low-thrust control toward developing a low-computational-cost transfer trajectory between libration orbits around the L1 and L2 libration points in the Sun-Earth system has been proposed in this paper. A new structure for a multi-objective transfer trajectory optimization model that divides the transfer trajectory into several segments and gives the dominations for invariant manifolds and low-thrust control in different segments has been established. To reduce the computational cost of multi-objective transfer trajectory optimization, a mixed sampling strategy-based adaptive surrogate model has been proposed. Numerical simulations show that the results obtained from the adaptive surrogate-based multi-objective optimization are in agreement with the results obtained using direct multi-objective optimization methods, and the computational workload of the adaptive surrogate-based multi-objective optimization is only approximately 10% of that of direct multi-objective optimization. Furthermore, the generating efficiency of the Pareto points of the adaptive surrogate-based multi-objective optimization is approximately 8 times that of the direct multi-objective optimization. Therefore, the proposed adaptive surrogate-based multi-objective optimization provides obvious advantages over direct multi-objective optimization methods.

  19. Modeling of Heating and Evaporation of FACE I Gasoline Fuel and its Surrogates

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2016-04-05

    The US Department of Energy has formulated different gasoline fuels called \\'\\'Fuels for Advanced Combustion Engines (FACE)\\'\\' to standardize their compositions. FACE I is a low octane number gasoline fuel with research octane number (RON) of approximately 70. The detailed hydrocarbon analysis (DHA) of FACE I shows that it contains 33 components. This large number of components cannot be handled in fuel spray simulation where thousands of droplets are directly injected in combustion chamber. These droplets are to be heated, broken-up, collided and evaporated simultaneously. Heating and evaporation of single droplet FACE I fuel was investigated. The heating and evaporation model accounts for the effects of finite thermal conductivity, finite liquid diffusivity and recirculation inside the droplet, referred to as the effective thermal conductivity/effective diffusivity (ETC/ED) model. The temporal variations of the liquid mass fractions of the droplet components were used to characterize the evaporation process. Components with similar evaporation characteristics were merged together. A representative component was initially chosen based on the highest initial mass fraction. Three 6 components surrogates, Surrogate 1-3, that match evaporation characteristics of FACE I have been formulated without keeping same mass fractions of different hydrocarbon types. Another two surrogates (Surrogate 4 and 5) were considered keeping same hydrocarbon type concentrations. A distillation based surrogate that matches measured distillation profile was proposed. The calculated molar mass, hydrogen-to-carbon (H/C) ratio and RON of Surrogate 4 and distillation based one are close to those of FACE I.

  20. Band-phase-randomized Surrogates to assess nonlinearity in non-stationary time series

    CERN Document Server

    Guarin, Diego; Orozco, Alvaro

    2011-01-01

    Testing for nonlinearity is one of the most important preprocessing steps in nonlinear time series analysis. Typically, this is done by means of the linear surrogate data methods. But it is a known fact that the validity of the results heavily depends on the stationarity of the time series. Since most physiological signals are non-stationary, it is easy to falsely detect nonlinearity using the linear surrogate data methods. In this document, we propose a methodology to extend the procedure for generating constrained surrogate time series in order to assess nonlinearity in non-stationary data. The method is based on the band-phase-randomized surrogates, which consists (contrary to the linear surrogate data methods) in randomizing only a portion of the Fourier phases in the high frequency band. Analysis of simulated time series showed that in comparison to the linear surrogate data method, our method is able to discriminate between linear stationarity, linear non-stationary and nonlinear time series. When apply...

  1. Growth and reproductive effects from dietary exposure to Aroclor 1268 in mink (Neovison vison), a surrogate model for marine mammals.

    Science.gov (United States)

    Folland, William R; Newsted, John L; Fitzgerald, Scott D; Fuchsman, Phyllis C; Bradley, Patrick W; Kern, John; Kannan, Kurunthachalam; Remington, Richard E; Zwiernik, Matthew J

    2016-03-01

    Polychlorinated biphenyls (PCBs) from the commercial mixture Aroclor 1268 were historically released into the Turtle-Brunswick River estuary (southeastern Georgia, USA) from industrial operations. Sum PCBs (ΣPCBs) in blubber samples from Turtle-Brunswick River estuary bottlenose dolphins (Tursiops truncatus) have been reported at concentrations more than 10-fold higher than those observed in dolphins from adjacent regional estuaries. Given that toxicity data specific to Aroclor 1268 and applicable to marine mammals are limited, predicting the toxic effects of Aroclor 1268 in dolphins is uncertain, particularly because of its unique congener profile and associated physiochemical characteristics compared with other PCB mixtures. American mink (Neovison vison) were chosen as a surrogate model for cetaceans to develop marine mammalian PCB toxicity benchmarks. Mink are a suitable surrogate species for cetaceans in toxicity studies because of similarities in diet and taxonomic class, and a characteristic sensitivity to PCBs provides a potential safety factor when using mink toxicology data for cross-species extrapolations. Effects of dietary exposure to Aroclor 1268 on reproduction, growth, and mortality in mink were compared with both a negative control and a positive control (3,3',4,4',5-pentachlorobiphenyl, PCB 126). Aroclor 1268 dietary ΣPCB concentrations ranged from 1.8 µg/g feed wet weight to 29 µg/g feed wet weight. Whelp success was unaffected by Aroclor 1268 exposure at any level. Treatment mean litter size, kit growth, and kit survival were adversely affected relative to the negative control at dietary ΣPCB concentrations of 10.6 µg/g feed wet weight and greater.

  2. Astrophysical Concepts

    CERN Document Server

    Harwit, Martin

    2006-01-01

    This classic text, aimed at senior undergraduates and beginning graduate students in physics and astronomy, presents a wide range of astrophysical concepts in sufficient depth to give the reader a quantitative understanding of the subject. Emphasizing physical concepts, the book outlines cosmic events but does not portray them in detail: it provides a series of astrophysical sketches. For this fourth edition, nearly every part of the text has been reconsidered and rewritten, new sections have been added to cover recent developments, and others have been extensively revised and brought up to date. The book begins with an outline of the scope of modern astrophysics and enumerates some of the outstanding problems faced in the field today. The basic physics needed to tackle these questions are developed in the next few chapters using specific astronomical processes as examples. The second half of the book enlarges on these topics and shows how we can obtain quantitative insight into the structure and evolution of...

  3. Nomenclature, variation, and the biological species concept in Lamasina (Lycaenidae: Theclinae: Eumaeini Nomenclatura, variação e o conceito biológico de espécie em Lamasina (Lycaenidae: Theclinae: Eumaeini

    Directory of Open Access Journals (Sweden)

    Robert K. Robbins

    2008-03-01

    Full Text Available The correct generic name for the species that belong to Eucharia Boisduval, 1870, a homonym, is either Annamaria D'Abrera & Bálint, 2001, which has been considered to be unavailable, or Lamasina Robbins, 2002, a replacement name for Eucharia. A recent re-interpretation of the original description of Annamaria was incorrect, and Annamaria is confirmed as being unavailable under Article 13.1 of the Code. A proposed neotype for Papilio ganimedes Cramer, 1775 is invalidated, and a possible syntype is illustrated. Results of an analysis of variation in the Lamasina ganimedes complex are distinctly different from those previously published and provide insufficient evidence to support the hypothesis that L. lathyi (Bálint, 2005 is distinct under a biological species concept. Lamasina lathyi is a synonym of L. ganimedes syn. nov. Statistical evidence overwhelmingly falsifies the published hypothesis that the L. rhaptissima (Johnson, 1991 (14 males and L. columbia (Bálint, 2005 (8 females species complexes are distinct rather than males and females of the same complex. Lamasina columbia is endemic to western Colombia. The hypothesis that L. rhapsodia (Bálint, 2005 from Bolivia is a distinct species is not better supported than the hypotheses that the one known specimen of L. rhapsodia is a geographical variant or an aberrant specimen. Lamasina rhapsodia is a synonym of L. rhaptissima syn. nov. Superficial similarity in ventral wing patterns in genera Paiwarria Kaye, 1904 and Lamasina is noted. A nomenclatural checklist for Lamasina is presented.O nome genérico correto para as espécies de Eucharia Boisduval, 1870, um homônimo, é Annamaria D'Abrera & Bálint, 2001, que tem sido considerado não válido, ou Lamasina Robbins, 2002, um nome substituto para Eucharia. Uma reinterpretação recente da descrição original de Annamaria é considerada incorreta, confirmando a não disponibilidade do nome com base no Artigo 13.1 do Código. O neótipo de

  4. Myotonometry as a Surrogate Measure of Muscle Strength

    Science.gov (United States)

    Ang, B. S.; Feeback, D. L.; Leonard, C. T.; Sykes, J.; Kruger, E.; Clarke, M. S. F.

    2007-01-01

    be significantly (p less than 0.01) correlated with contemporaneous myotonometer measurements made on the rectis femoris muscle in a total of 16 healthy subjects (8 males, 8 females). Further-more, this device has been operationally tested during parabolic flight demonstrating its suitability for use in a microgravity environment. Our data indicates that the Myotonometer is a viable surrogate measure of muscle contractile state/tone and of muscle strength/force production. Additional studies are required to assess the suitability of this technique for assessing these measures in de-conditioned subjects such as crew-members.

  5. Is Diaphragm Motion a Good Surrogate for Liver Tumor Motion?

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Juan [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); School of Information Science and Engineering, Shandong University, Jinan, Shandong (China); Cai, Jing [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Wang, Hongjun [School of Information Science and Engineering, Shandong University, Jinan, Shandong (China); Chang, Zheng; Czito, Brian G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Bashir, Mustafa R. [Department of Radiology, Duke University Medical Center, Durham, North Carolina (United States); Palta, Manisha [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Yin, Fang-Fang, E-mail: fangfang.yin@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States)

    2014-11-15

    Purpose: To evaluate the relationship between liver tumor motion and diaphragm motion. Methods and Materials: Fourteen patients with hepatocellular carcinoma (10 of 14) or liver metastases (4 of 14) undergoing radiation therapy were included in this study. All patients underwent single-slice cine–magnetic resonance imaging simulations across the center of the tumor in 3 orthogonal planes. Tumor and diaphragm motion trajectories in the superior–inferior (SI), anterior–posterior (AP), and medial–lateral (ML) directions were obtained using an in-house-developed normalized cross-correlation–based tracking technique. Agreement between the tumor and diaphragm motion was assessed by calculating phase difference percentage, intraclass correlation coefficient, and Bland-Altman analysis (Diff). The distance between the tumor and tracked diaphragm area was analyzed to understand its impact on the correlation between the 2 motions. Results: Of all patients, the mean (±standard deviation) phase difference percentage values were 7.1% ± 1.1%, 4.5% ± 0.5%, and 17.5% ± 4.5% in the SI, AP, and ML directions, respectively. The mean intraclass correlation coefficient values were 0.98 ± 0.02, 0.97 ± 0.02, and 0.08 ± 0.06 in the SI, AP, and ML directions, respectively. The mean Diff values were 2.8 ± 1.4 mm, 2.4 ± 1.1 mm, and 2.2 ± 0.5 mm in the SI, AP, and ML directions, respectively. Tumor and diaphragm motions had high concordance when the distance between the tumor and tracked diaphragm area was small. Conclusions: This study showed that liver tumor motion had good correlation with diaphragm motion in the SI and AP directions, indicating diaphragm motion in the SI and AP directions could potentially be used as a reliable surrogate for liver tumor motion.

  6. A Development of a Human Cranial Bone Surrogate for Impact Studies

    Directory of Open Access Journals (Sweden)

    Jack C Roberts

    2013-10-01

    Full Text Available In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the 3-layer (inner table-diplöe-outer table architecture of the human skull. The materials selected to represent the surrogate cranial tables consisted of two different epoxy resins systems with random milled glass fiber to enhance the strength and stiffness and the materials to represent the surrogate diplöe consisted of three low density foams. Forty-one three-point bending fracture toughness tests were performed on nine material combinations. The materials that best represented the fracture toughness of cranial tables were then selected and formed into tensile samples and tested. These materials were then used with the two surrogate diplöe foam materials to create the three layer surrogate cranial bone samples for three point bending tests. Drop tower tests were performed on flat samples created from these materials and the fracture patterns were very similar to the linear fractures seen in pendulum impacts of intact human skulls. The surrogate cranial tables had the quasi-static fracture toughness and tensile strength of 2.5 MPa√m and 53 ± 4.9 MPa, respectively, while the same properties of human compact bone were 3.1 ± 1.8 MPa√m and 68 ± 18 MPa, respectively. The cranial surrogate had a quasi-static bending strength of 68 ± 5.7 MPa, while that of cranial bone was 82 ± 26 MPa. This material/design is currently being used to construct spherical shell samples for drop tower and ballistic tests.

  7. Observing Migration and Burial of Unexploded Ordnance in the Nearshore Environment with Instrumented Surrogates

    Science.gov (United States)

    Bruder, B. L.; Cristaudo, D.; Puleo, J. A.

    2016-12-01

    Prior to 1972, it was legal and common practice to unload unexploded ordnance (UXO) into the ocean. Only 60-100 miles off the US coast alone there are 72 dumping sites where it is estimated 31 million pounds of UXO lie. As recently as 2015, UXO have been found not only in the nearshore environment, but on populated beaches. Thus, understanding the migration and burial of these objects is not only of oceanographic interest, but a matter of public safety. The presented project evaluates the efficacy of instrumented UXO surrogates for observing munition migration and burial. Instrumented surrogates were exposed to near prototype scale wave conditions over a mobile bed at the Littoral Warfare Environment at Aberdeen Test Center, MD. Surrogates were deployed in the swash zone, inner and outer surf zones. Dependent on munition size, surrogates housed multiple suites of self-logging sensors. Sensor suites included different combinations of inertial motion units, ultra-wideband tracking tags, pressure transducers, shock recorders, and photocells. Preliminary results show sensor suites can resolve various types of surrogate movement. Pressure transducers accurately record ambient wave conditions as well as changes in mean depth due to surrogate migration. Inertial motion units resolve munition accelerations for rolling and translational motion. Inertial motion unit data is used to estimate trajectory as well when coupled with mean depth and bathymetric data. Photocells, which measure ambient light, resolve munition burial as well as serve as proxies for surrounding environmental conditions such as suspended sediment and water depth. The presented project will continue to utilize and couple surrogate sensor data to resolve munition movement and burial under different conditions. Knowledge of munition migration helps focus UXO detection and recovery, conserving US military and coastal resources.

  8. Primary Reference Fuels (PRFs) as Surrogates for Low Sensitivity Gasoline Fuels

    KAUST Repository

    Bhavani Shankar, Vijai Shankar

    2016-04-05

    Primary Reference Fuels (PRFs) - binary mixtures of n-heptane and iso-octane based on Research Octane Number (RON) - are popular gasoline surrogates for modeling combustion in spark ignition engines. The use of these two component surrogates to represent real gasoline fuels for simulations of HCCI/PCCI engines needs further consideration, as the mode of combustion is very different in these engines (i.e. the combustion process is mainly controlled by the reactivity of the fuel). This study presents an experimental evaluation of PRF surrogates for four real gasoline fuels termed FACE (Fuels for Advanced Combustion Engines) A, C, I, and J in a motored CFR (Cooperative Fuels Research) engine. This approach enables the surrogate mixtures to be evaluated purely from a chemical kinetic perspective. The gasoline fuels considered in this study have very low sensitivities, S (RON-MON), and also exhibit two-stage ignition behavior. The first stage heat release, which is termed Low Temperature Heat Release (LTHR), controls the combustion phasing in this operating mode. As a result, the performance of the PRF surrogates was evaluated by its ability to mimic the low temperature chemical reactivity of the real gasoline fuels. This was achieved by comparing the LTHR from the engine pressure histories. The PRF surrogates were able to consistently reproduce the amount of LTHR, closely match the phasing of LTHR, and the compression ratio for the start of hot ignition of the real gasoline fuels. This suggests that the octane quality of a surrogate fuel is a good indicator of the fuel’s reactivity across low (LTC), negative temperature coefficient (NTC), and high temperature chemical (HTC) reactivity regimes.

  9. Ovulation Statuses of Surrogate Gilts Are Associated with the Efficiency of Excellent Pig Cloning.

    Directory of Open Access Journals (Sweden)

    Yanjun Huan

    Full Text Available Somatic cell nuclear transfer (SCNT is an assisted reproductive technique that can produce multiple copies of excellent livestock. However, low cloning efficiency limits the application of SCNT. In this study, we systematically investigated the major influencing factors related to the overall cloning efficiency in pigs. Here, 13620 cloned embryos derived from excellent pigs were transferred into 79 surrogate gilts, and 119 live cloned piglets were eventually generated. During cloning, group of cloned embryos derived from excellent Landrace or Large white pigs presented no significant differences of cleavage and blastocyst rates, blastocyst cell numbers, surrogate pregnancy and delivery rates, average numbers of piglets born and alive and cloning efficiencies, and group of 101-150, 151-200 or 201-250 cloned embryos transferred per surrogate also displayed a similar developmental efficiency. When estrus stage of surrogate gilts was compared, group of embryo transfer on Day 2 of estrus showed significantly higher pregnancy rate, delivery rate, average number of piglets born, average alive piglet number or cloning efficiency than group on Day 1, Day 3, Day 4 or Day 5, respectively (P<0.05. And, in comparison with the preovulation and postovulation groups, group of surrogate gilts during periovulation displayed a significantly higher overall cloning efficiency (P<0.05. Further investigation of surrogate estrus stage and ovulation status displayed that ovulation status was the real factor underlying estrus stage to determine the overall cloning efficiency. And more, follicle puncture for preovulation, not transfer position shallowed for preovulation or deepened for postovulation, significantly improved the average number of piglets alive and cloning efficiency (P<0.05. In conclusion, our results demonstrated that ovulation status of surrogate gilts was the fundamental factor determining the overall cloning efficiency of excellent pigs, and follicle

  10. Real-time characterization of partially observed epidemics using surrogate models.

    Energy Technology Data Exchange (ETDEWEB)

    Safta, Cosmin; Ray, Jaideep; Lefantzi, Sophia; Crary, David (Applied Research Associates, Arlington, VA); Sargsyan, Khachik; Cheng, Karen (Applied Research Associates, Arlington, VA)

    2011-09-01

    We present a statistical method, predicated on the use of surrogate models, for the 'real-time' characterization of partially observed epidemics. Observations consist of counts of symptomatic patients, diagnosed with the disease, that may be available in the early epoch of an ongoing outbreak. Characterization, in this context, refers to estimation of epidemiological parameters that can be used to provide short-term forecasts of the ongoing epidemic, as well as to provide gross information on the dynamics of the etiologic agent in the affected population e.g., the time-dependent infection rate. The characterization problem is formulated as a Bayesian inverse problem, and epidemiological parameters are estimated as distributions using a Markov chain Monte Carlo (MCMC) method, thus quantifying the uncertainty in the estimates. In some cases, the inverse problem can be computationally expensive, primarily due to the epidemic simulator used inside the inversion algorithm. We present a method, based on replacing the epidemiological model with computationally inexpensive surrogates, that can reduce the computational time to minutes, without a significant loss of accuracy. The surrogates are created by projecting the output of an epidemiological model on a set of polynomial chaos bases; thereafter, computations involving the surrogate model reduce to evaluations of a polynomial. We find that the epidemic characterizations obtained with the surrogate models is very close to that obtained with the original model. We also find that the number of projections required to construct a surrogate model is O(10)-O(10{sup 2}) less than the number of samples required by the MCMC to construct a stationary posterior distribution; thus, depending upon the epidemiological models in question, it may be possible to omit the offline creation and caching of surrogate models, prior to their use in an inverse problem. The technique is demonstrated on synthetic data as well as

  11. Surrogate models and optimal design of experiments for chemical kinetics applications

    KAUST Repository

    Bisetti, Fabrizio

    2015-01-07

    Kinetic models for reactive flow applications comprise hundreds of reactions describing the complex interaction among many chemical species. The detailed knowledge of the reaction parameters is a key component of the design cycle of next-generation combustion devices, which aim at improving conversion efficiency and reducing pollutant emissions. Shock tubes are a laboratory scale experimental configuration, which is widely used for the study of reaction rate parameters. Important uncertainties exist in the values of the thousands of parameters included in the most advanced kinetic models. This talk discusses the application of uncertainty quantification (UQ) methods to the analysis of shock tube data as well as the design of shock tube experiments. Attention is focused on a spectral framework in which uncertain inputs are parameterized in terms of canonical random variables, and quantities of interest (QoIs) are expressed in terms of a mean-square convergent series of orthogonal polynomials acting on these variables. We outline the implementation of a recent spectral collocation approach for determining the unknown coefficients of the expansion, namely using a sparse, adaptive pseudo-spectral construction that enables us to obtain surrogates for the QoIs accurately and efficiently. We first discuss the utility of the resulting expressions in quantifying the sensitivity of QoIs to uncertain inputs, and in the Bayesian inference key physical parameters from experimental measurements. We then discuss the application of these techniques to the analysis of shock-tube data and the optimal design of shock-tube experiments for two key reactions in combustion kinetics: the chain-brancing reaction H + O2 ←→ OH + O and the reaction of Furans with the hydroxyl radical OH.

  12. Virucidal effect of cold atmospheric gaseous plasma on feline calicivirus, a surrogate for human norovirus.

    Science.gov (United States)

    Aboubakr, Hamada A; Williams, Paul; Gangal, Urvashi; Youssef, Mohammed M; El-Sohaimy, Sobhy A A; Bruggeman, Peter J; Goyal, Sagar M

    2015-06-01

    Minimal food-processing methods are not effective against foodborne viruses, such as human norovirus (NV). It is important, therefore, to explore novel nonthermal technologies for decontamination of foods eaten fresh, minimally processed and ready-to-eat foods, and food contact surfaces. We studied the in vitro virucidal activity of cold atmospheric gaseous plasma (CGP) against feline calicivirus (FCV), a surrogate of NV. Factors affecting the virucidal activity of CGP (a so-called radio frequency atmospheric pressure plasma jet) were the plasma generation power, the exposure time and distance, the plasma feed gas mixture, and the virus suspension medium. Exposure to 2.5-W argon (Ar) plasma caused a 5.55 log10 unit reduction in the FCV titer within 120 s. The reduction in the virus titer increased with increasing exposure time and decreasing exposure distance. Of the four plasma gas mixtures studied (Ar, Ar plus 1% O2, Ar plus 1% dry air, and Ar plus 0.27% water), Ar plus 1% O2 plasma treatment had the highest virucidal effect: more than 6.0 log10 units of the virus after 15 s of exposure. The lowest virus reduction was observed with Ar plus 0.27% water plasma treatment (5 log10 unit reduction after 120 s). The highest reduction in titer was observed when the virus was suspended in distilled water. Changes in temperature and pH and formation of H2O2 were not responsible for the virucidal effect of plasma. The oxidation of viral capsid proteins by plasma-produced reactive oxygen and nitrogen species in the solution was thought to be responsible for the virucidal effect. In conclusion, CGP exhibits virucidal activity in vitro and has the potential to combat viral contamination in foods and on food preparation surfaces.

  13. Potassium ferrate [Fe(VI] does not mediate self-sterilization of a surrogate mars soil

    Directory of Open Access Journals (Sweden)

    Paszczynski Andrzej

    2003-03-01

    Full Text Available Abstract Background Martian soil is thought to be enriched with strong oxidants such as peroxides and/or iron in high oxidation states that might destroy biological materials. There is also a high flux of ultraviolet radiation at the surface of Mars. Thus, Mars may be inhospitable to life as we know it on Earth. We examined the hypothesis that if the soil of Mars contains ferrates [Fe(VI], the strongest of the proposed oxidizing species, and also is exposed to high fluxes of UV radiation, it will be self-sterilizing. Results Under ambient conditions (25°C, oxygen and water present K2FeO4 mixed into sand mineralized some reactive organic molecules to CO2, while less reactive compounds were not degraded. Dried endospores of Bacillus subtilis incubated in a Mars surrogate soil comprised of dry silica sand containing 20% by weight K2FeO4 and under conditions similar to those now on Mars (extreme desiccation, cold, and a CO2-dominated atmosphere were resistant to killing by the ferrate-enriched sand. Similar results were observed with permanganate. Spores in oxidant-enriched sand exposed to high fluxes of UV light were protected from the sporocidal activity of the radiation below about 5 mm depths. Conclusion Based on our data and previously published descriptions of ancient but dormant life forms on Earth, we suggest that if entities resembling bacterial endospores were produced at some point by life forms on Mars, they might still be present and viable, given appropriate germination conditions. Endospores delivered to Mars on spacecraft would possibly survive and potentially compromise life detection experiments.

  14. Antiviral effects of black raspberry (Rubus coreanus) juice on foodborne viral surrogates.

    Science.gov (United States)

    Oh, Mi; Bae, Seon Young; Lee, Ji-Hye; Cho, Ki Joon; Kim, Kyung Hyun; Chung, Mi Sook

    2012-10-01

    Abstract Human noroviruses (HuNoVs) are the most frequent cause of foodborne viral gastroenteritis, causing approximately 90% of non-bacterial epidemic outbreaks around the world. Rubus coreanus is a species of black raspberry, rich in polyphenols, and known to exert anti-inflammatory, antibacterial, and antiviral activities. In the present study, the antiviral effects of R. coreanus juice (black raspberry [BRB] juice) on foodborne viral surrogates, murine norovirus-1 (MNV-1) and feline calicivirus-F9 (FCV-F9), were compared with those of cranberry juice, grape juice, and orange juice by plaque assays. Among the four juices tested, BRB juice was the most effective in reducing plaques formation of these viruses. Time-of-addition experiments were designed to determine the mechanism of action of BRB juice on MNV-1 and FCV-F9. The maximal antiviral effect of BRB juice against MNV-1 was observed when it was added to RAW 264.7 cells (mouse leukemic monocyte macrophage cell line) simultaneously with the virus. Pre-treatment of either Crandell Reese Feline Kidney cells or FCV-F9 with BRB juice exhibited significant antiviral activity. The inhibition of viral infection by BRB juice on MNV-1 and FCV-F9 probably occurs at the internalization of virions into the cell or the attachment of the viral surface protein to the cellular receptor. The polyphenol components in BRB (i.e., gallic acid and quercetin), however, did not show any activity against these viruses. Our data provide great promise for the utilization of BRB in the prevention of foodborne viral outbreaks.

  15. Definitions and validation criteria for biomarkers and surrogate endpoints: development and testing of a quantitative hierarchical levels of evidence schema

    DEFF Research Database (Denmark)

    Lassere, Marissa N; Johnson, Kent R; Boers, Maarten

    2007-01-01

    to develop a hierarchical schema that systematically evaluates and ranks the surrogacy status of biomarkers and surrogates; and to obtain feedback from stakeholders. METHODS: After a systematic search of Medline and Embase on biomarkers, surrogate (outcomes, endpoints, markers, indicators), intermediate...... endpoints, and leading indicators, a quantitative surrogate validation schema was developed and subsequently evaluated at a stakeholder workshop. RESULTS: The search identified several classification schema and definitions. Components of these were incorporated into a new quantitative surrogate validation...... of the National Institutes of Health definitions of biomarker, surrogate endpoint, and clinical endpoint was useful. CONCLUSION: Further development and application of this schema provides incentives and guidance for effective biomarker and surrogate endpoint research, and more efficient drug discovery...

  16. Development of a multi-objective optimization algorithm using surrogate models for coastal aquifer management

    Science.gov (United States)

    Kourakos, George; Mantoglou, Aristotelis

    2013-02-01

    SummaryThe demand for fresh water in coastal areas and islands can be very high due to increased local needs and tourism. A multi-objective optimization methodology is developed, involving minimization of economic and environmental costs while satisfying water demand. The methodology considers desalinization of pumped water and injection of treated water into the aquifer. Variable density aquifer models are computationally intractable when integrated in optimization algorithms. In order to alleviate this problem, a multi-objective optimization algorithm is developed combining surrogate models based on Modular Neural Networks [MOSA(MNNs)]. The surrogate models are trained adaptively during optimization based on a genetic algorithm. In the crossover step, each pair of parents generates a pool of offspring which are evaluated using the fast surrogate model. Then, the most promising offspring are evaluated using the exact numerical model. This procedure eliminates errors in Pareto solution due to imprecise predictions of the surrogate model. The method has important advancements compared to previous methods such as precise evaluation of the Pareto set and alleviation of propagation of errors due to surrogate model approximations. The method is applied to an aquifer in the Greek island of Santorini. The results show that the new MOSA(MNN) algorithm offers significant reduction in computational time compared to previous methods (in the case study it requires only 5% of the time required by other methods). Further, the Pareto solution is better than the solution obtained by alternative algorithms.

  17. Surrogate utility estimation by long-term partners and unfamiliar dyads

    Directory of Open Access Journals (Sweden)

    Richard J Tunney

    2015-03-01

    Full Text Available To what extent are people able to make predictions about other people’s preferences and values? We report two experiments that present a novel method assessing some of the basic processes in surrogate decision-making, namely surrogate-utility estimation. In each experiment participants formed dyads who were asked to assign utilities to health related items and commodity items, and to predict their partner’s utility judgments for the same items. In experiment one we showed that older adults in long-term relationships were able to accurately predict their partner’s wishes. In experiment two we showed that younger adults who were relatively unfamiliar with one another were also able to predict other people’s wishes. Crucially we demonstrated that these judgments were accurate even after partialling out each participant’s own preferences indicating that in order to make surrogate utility estimations people engage in perspective-taking rather than simple anchoring and adjustment, suggesting that utility estimation is not the cause of inaccuracy in surrogate decision-making. The data and implications are discussed with respect to theories of surrogate decision-making.

  18. Surrogate POD models for building forming limit diagrams of parameterized sheet metal forming applications

    Science.gov (United States)

    Hamdaoui, M.; Le Quilliec, Guénhaël; Breitkopf, Piotr; Villon, Pierre

    2013-05-01

    The aim of this work is to present a surrogate POD (Proper Orthogonal Decomposition) approach for building forming limit diagrams at minimum cost for parameterized sheet metal formed work-pieces. First, a Latin Hypercube Sampling is performed on the design parameter space. Then, at each design site, displacement fields are computed using the popular open-source finite element software Code_Aster. Then, the method of snapshots is used for POD mode determination. POD coefficients are interpolated using kriging. Furthermore, an error analysis of the surrogate POD model is performed on a validation set. It is shown that on the considered use case the accuracy of the surrogate POD model is excellent for the representation of finite element displacement fields. The validated surrogate POD model is then used to build forming limit diagrams (FLD) for any design parameter to assess the quality of stamped metal sheets. Using the surrogate POD model, the Green-Lagrange strain tensor is derived, then major and minor principal deformations are determined at Gauss points for each mesh element. Furthermore, a signed distance between the forming limit curve in rupture and the obtained cloud of points in the plane (ɛ2, ɛ1) is computed to assess the quality of the formed workpiece. The minimization of this signed distance allows determining the safest design for the chosen use case.

  19. Stochastic structural optimization using particle swarm optimization, surrogate models and Bayesian statistics

    Institute of Scientific and Technical Information of China (English)

    Jongbin Im; Jungsun Park

    2013-01-01

    This paper focuses on a method to solve structural optimization problems using particle swarm optimization (PSO),surrogate models and Bayesian statistics.PSO is a random/stochastic search algorithm designed to find the global optimum.However,PSO needs many evaluations compared to gradient-based optimization.This means PSO increases the analysis costs of structural optimization.One of the methods to reduce computing costs in stochastic optimization is to use approximation techniques.In this work,surrogate models are used,including the response surface method (RSM) and Kriging.When surrogate models are used,there are some errors between exact values and approximated values.These errors decrease the reliability of the optimum values and discard the realistic approximation of using surrogate models.In this paper,Bayesian statistics is used to obtain more reliable results.To verify and confirm the efficiency of the proposed method using surrogate models and Bayesian statistics for stochastic structural optimization,two numerical examples are optimized,and the optimization of a hub sleeve is demonstrated as a practical problem.

  20. Time-varying surrogate data to assess nonlinearity in nonstationary time series: application to heart rate variability.

    Science.gov (United States)

    Faes, Luca; Zhao, He; Chon, Ki H; Nollo, Giandomenico

    2009-03-01

    We propose a method to extend to time-varying (TV) systems the procedure for generating typical surrogate time series, in order to test the presence of nonlinear dynamics in potentially nonstationary signals. The method is based on fitting a TV autoregressive (AR) model to the original series and then regressing the model coefficients with random replacements of the model residuals to generate TV AR surrogate series. The proposed surrogate series were used in combination with a TV sample entropy (SE) discriminating statistic to assess nonlinearity in both simulated and experimental time series, in comparison with traditional time-invariant (TIV) surrogates combined with the TIV SE discriminating statistic. Analysis of simulated time series showed that using TIV surrogates, linear nonstationary time series may be erroneously regarded as nonlinear and weak TV nonlinearities may remain unrevealed, while the use of TV AR surrogates markedly increases the probability of a correct interpretation. Application to short (500 beats) heart rate variability (HRV) time series recorded at rest (R), after head-up tilt (T), and during paced breathing (PB) showed: 1) modifications of the SE statistic that were well interpretable with the known cardiovascular physiology; 2) significant contribution of nonlinear dynamics to HRV in all conditions, with significant increase during PB at 0.2 Hz respiration rate; and 3) a disagreement between TV AR surrogates and TIV surrogates in about a quarter of the series, suggesting that nonstationarity may affect HRV recordings and bias the outcome of the traditional surrogate-based nonlinearity test.

  1. MACROALGAL VOLUME: A SURROGATE FOR BIOMASS IN SOME GREEN ALGAE

    Science.gov (United States)

    Two green algal morphotypes, filamentous species (e.g., Chaetomorpha spp.) and flattened or tubular (e.g.,Ulva spp. and Enteromorpha spp.) were collected from 63 sites within the Yaquina Bay estuary (Newport, OR) and used to compare an in situ volumetric biomass estimator to the...

  2. The role of time and species identities in spatial patterns of species richness and conservation.

    Science.gov (United States)

    Hewitt, Judi E; Thrush, Simon F; Ellingsen, Kari E

    2016-10-01

    Many conservation actions are justified on the basis of managing biodiversity. Biodiversity, in terms of species richness, is largely the product of rare species. This is problematic because the intensity of sampling needed to characterize communities and patterns of rarity or to justify the use of surrogates has biased sampling in favor of space over time. However, environmental fluctuations interacting with community dynamics lead to temporal variations in where and when species occur, potentially affecting conservation planning by generating uncertainty about results of species distribution modeling (including range determinations), selection of surrogates for biodiversity, and the proportion of biodiversity composed of rare species. To have confidence in the evidence base for conservation actions, one must consider whether temporal replication is necessary to produce broad inferences. Using approximately 20 years of macrofaunal data from tidal flats in 2 harbors, we explored variation in the identity of rare, common, restricted range, and widespread species over time and space. Over time, rare taxa were more likely to increase in abundance or occurrence than to remain rare or disappear and to exhibit temporal patterns in their occurrence. Space-time congruency in ranges (i.e., spatially widespread taxa were also temporally widespread) was observed only where samples were collected across an environmental gradient. Fifteen percent of the taxa in both harbors changed over time from having spatially restricted ranges to having widespread ranges. Our findings suggest that rare species can provide stability against environmental change, because the majority of species were not random transients, but that selection of biodiversity surrogates requires temporal validation. Rarity needs to be considered both spatially and temporally, as species that occur randomly over time are likely to play a different role in ecosystem functioning than those exhibiting temporal

  3. Neutron-induced cross sections of actinides via the surrogate-reaction method

    Directory of Open Access Journals (Sweden)

    Ducasse Q.

    2013-12-01

    Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method has to be investigated. In particular, the absence of a compound nucleus formation and the Jπ dependence of the decay probabilities may question the method. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutron-induced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. The first results are hereby presented.

  4. Enhanced CRISPR/Cas9-mediated biallelic genome targeting with dual surrogate reporter-integrated donors.

    Science.gov (United States)

    Wu, Yun; Xu, Kun; Ren, Chonghua; Li, Xinyi; Lv, Huijiao; Han, Furong; Wei, Zehui; Wang, Xin; Zhang, Zhiying

    2017-03-01

    The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) system has recently emerged as a simple, yet powerful genome engineering tool, which has been widely used for genome modification in various organisms and cell types. However, screening biallelic genome-modified cells is often time-consuming and technically challenging. In this study, we incorporated two different surrogate reporter cassettes into paired donor plasmids, which were used as both the surrogate reporters and the knock-in donors. By applying our dual surrogate reporter-integrated donor system, we demonstrate high frequency of CRISPR/Cas9-mediated biallelic genome integration in both human HEK293T and porcine PK15 cells (34.09% and 18.18%, respectively). Our work provides a powerful genetic tool for assisting the selection and enrichment of cells with targeted biallelic genome modification. © 2017 Federation of European Biochemical Societies.

  5. Two-step nuclear reactions: The Surrogate Method, the Trojan Horse Method and their common foundations

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, Mahir S. [DCTA, Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, SP (Brazil); Universidade de Sao Paulo, Instituto de Estudos Avancados, C. P. 72012, Sao Paulo, SP (Brazil); Universidade de Sao Paulo, Instituto de Fisica, C. P. 66318, Sao Paulo, SP (Brazil)

    2017-05-15

    In this Letter I argue that the Surrogate Method, used to extract the fast neutron capture cross section on actinide target nuclei, which has important practical application for the next generation of breeder reactors, and the Trojan Horse Method employed to extract reactions of importance to nuclear astrophysics, have a common foundation, the Inclusive Non-Elastic Breakup (INEB) Theory. Whereas the Surrogate Method relies on the premise that the extracted neutron cross section in a (d, p) reaction is predominantly a compound-nucleus one, the Trojan Horse Method assumes a predominantly direct process for the secondary reaction induced by the surrogate fragment. In general, both methods contain both direct and compound contributions, and I show how these seemingly distinct methods are in fact the same but at different energies and different kinematic regions. The unifying theory is the rather well developed INEB theory. (orig.)

  6. Validating (d,pγ as a Surrogate for Neutron Capture

    Directory of Open Access Journals (Sweden)

    Ratkiewicz A.

    2015-01-01

    Full Text Available The r-process is responsible for creating roughly half of the elements heavier than iron. It has recently become understood that the rates at which neutron capture reactions proceed at late times in the r-process may dramatically affect the final abundance pattern. However, direct measurements of neutron capture reaction rates on exotic nuclei are exceptionally difficult, necessitating the development of indirect approaches such as the surrogate technique. The (d,pγ reaction at low energies was identified as a promising surrogate for the (n,γ reaction, as both reactions share many characteristics. We report on a program to validate (d,pγ as a surrogate for (n,γ using 95Mo as a target. The experimental campaign includes direct measurements of the γ-ray intensities from the decay of excited states populated in the 95Mo(n,γ and 95Mo(d,pγ reactions.

  7. Analytical approximations for temperature dependent thermophysical properties of supercritical diesel fuel surrogates used in combustion modeling

    Science.gov (United States)

    Kumar, Abhinav; Saini, Vishnu; Dondapati, Raja Sekhar; Usurumarti, Preeti Rao

    2017-07-01

    Supercritical fluid technology is introduced to combat the critical challenges related with emissions, incomplete and clean diesel fuel combustion. The chemical kinetics of diesel fuel is a strong function of temperature. As surrogate fuels have a potential to represent a real diesel fuel, thermophysical properties of such fuels have been studied in this present work as a function of temperature. Further, two diesel surrogate fuels which have been identified as the components of actual diesel fuel for jet engines are studied and thermophysical properties of these two surrogates are evaluated as a function of temperature at critical pressure. In addition, the accuracy and reliability of the developed correlations is estimated using two statistical parameters such as Absolute Average of Relative Error (AARE) and Sum of Average Residues (SAR). Results show an excellent agreement between the standard data and the correlated property values.

  8. Validating (d,pγ) as a surrogate for neutron capture

    Energy Technology Data Exchange (ETDEWEB)

    Ratkiewicz, A. [Rutgers Univ., New Brunswick, NJ (United States); Cizewski, J. A. [Rutgers Univ., New Brunswick, NJ (United States); Pain, S. D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Adekola, A. S. [Rutgers Univ., New Brunswick, NJ (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fotiadis, Nikolaos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McCleskey, M. [Texas A & M Univ., College Station, TX (United States); Burcher, S. [Rutgers Univ., New Brunswick, NJ (United States); Shand, C. M [Rutgers Univ., New Brunswick, NJ (United States); Austin, R. A. E. [Saint Mary' s Univ., Halifax (Canada); Baugher, T. [Rutgers Univ., New Brunswick, NJ (United States); Carpenter, M. P. [Argonne National Lab. (ANL), Argonne, IL (United States); Devlin, Matthew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hardy, S. [Rutgers Univ., New Brunswick, NJ (United States); Hatarik, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Howard, M. E. [Rutgers Univ., New Brunswick, NJ (United States); Hughes, R. O. [Univ. of Richmond, VA (United States); Jones, K. L. [Univ. of Tennessee, Knoxville, TN (United States); Kozub, R. L. [Tennessee Technological Univ., Cookeville, TN (United States); Lister, C. J. [Univ. of Massachusetts, Lowell, MA (United States); Manning, B. [Rutgers Univ., New Brunswick, NJ (United States); O' Donnell, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Peters, W. A. [oak ridge associated Univ., TN (United States); Ross, T. J. [Univ. of Richmond, VA (United States); Scielzo, N. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Seweryniak, D. [Argonne National Lab. (ANL), Argonne, IL (United States); Zhu, S. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-02-13

    The r-process is responsible for creating roughly half of the elements heavier than iron. It has recently become understood that the rates at which neutron capture reactions proceed at late times in the r-process may dramatically affect the final abundance pattern. However, direct measurements of neutron capture reaction rates on exotic nuclei are exceptionally difficult, necessitating the development of indirect approaches such as the surrogate technique. The (d,pγ) reaction at low energies was identified as a promising surrogate for the (n,γ) reaction, as both reactions share many characteristics. We report on a program to validate (d,pγ) as a surrogate for (n,γ) using 95Mo as a target. The experimental campaign includes direct measurements of the γ-ray intensities from the decay of excited states populated in the 95Mo(n,γ) and 95Mo(d,pγ) reactions.

  9. Kinetic Modeling of Gasoline Surrogate Components and Mixtures under Engine Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mehl, M; Pitz, W J; Westbrook, C K; Curran, H J

    2010-01-11

    Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, an improved version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multicomponent gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines (3-50 atm, 650-1200K, stoichiometric fuel/air mixtures). Simulation results are discussed focusing attention on the mixing effects of the fuel components.

  10. Two-step nuclear reactions: The Surrogate Method, the Trojan Horse Method and their common foundations

    Science.gov (United States)

    Hussein, Mahir S.

    2017-05-01

    In this Letter I argue that the Surrogate Method, used to extract the fast neutron capture cross section on actinide target nuclei, which has important practical application for the next generation of breeder reactors, and the Trojan Horse Method employed to extract reactions of importance to nuclear astrophysics, have a common foundation, the Inclusive Non-Elastic Breakup (INEB) Theory. Whereas the Surrogate Method relies on the premise that the extracted neutron cross section in a ( d, p) reaction is predominantly a compound-nucleus one, the Trojan Horse Method assumes a predominantly direct process for the secondary reaction induced by the surrogate fragment. In general, both methods contain both direct and compound contributions, and I show how these seemingly distinct methods are in fact the same but at different energies and different kinematic regions. The unifying theory is the rather well developed INEB theory.

  11. Neutron-induced cross sections of actinides via the surrogate-reaction method

    Directory of Open Access Journals (Sweden)

    Tveten G. M.

    2013-03-01

    Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method for extracting capture cross sections has to be investigated. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutroninduced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. First results are presented and discussed.

  12. Validating (d,p gamma) as a Surrogate for Neutron Capture

    Energy Technology Data Exchange (ETDEWEB)

    Ratkiewicz, A. [Rutgers University; Cizewski, J. A. [Rutgers University; Pain, S. [Oak Ridge National Laboratory (ORNL); Adekola, A. S. [Rutgers University; Burke, J. T. [Lawrence Livermore National Laboratory (LLNL); Casperson, R.J. [Lawrence Livermore National Laboratory (LLNL); Fotiades, N. [Los Alamos National Laboratory (LANL); McCleskey, M. [Texas A& M University; Burcher, S. [Rutgers University; Shand, C. M. [Rutgers Univ./Univ. of Surrey, UK; Austin, R. A. E. [Saint Mary’s University, Halifa, Canada; Baugher, T. [Rutgers University; Carpenter, M. P. [Argonne National Laboratory (ANL); Devlin, M. [Los Alamos National Laboratory (LANL); Escher, J. E. [Lawrence Livermore National Laboratory (LLNL); Hardy, S. [Rutgers Univ./Univ. of Surrey, UK; Hatarik, R. [Lawrence Livermore National Laboratory (LLNL); Howard, M. [Rutgers University; Hughes, R. [University of Richmond, VA; Jones, K. L. [University of Tennessee, Knoxville (UTK); Kozub, R. L. [Tennessee Technological University (TTU); Lister, C. J. [University of Massachusetts, Lowell; Manning, B. [Rutgers University; O' Donnell, J. M. [Los Alamos National Laboratory (LANL); Peters, W. A. [Oak Ridge Associated Universities (ORAU); Ross, T.J. [University of Richmond, VA; Scielzo, N.D. [Lawrence Livermore National Laboratory (LLNL); Seweryniak, D. [Argonne National Laboratory (ANL); Zhu, S. [Argonne National Laboratory (ANL)

    2015-01-01

    The r-process is responsible for creating roughly half of the elements heavier than iron. It has recently become understood that the rates at which neutron capture reactions proceed at late times in the rprocess may dramatically affect the final abundance pattern. However, direct measurements of neutron capture reaction rates on exotic nuclei are exceptionally difficult, necessitating the development of indirect approaches such as the surrogate technique. The (d,py) reaction at low energies was identified as a promising surrogate for the (n,y) reaction, as both reactions share many characteristics. We report on a program to validate (d,py) as a surrogate for (n,y) using 95Mo as a target. The experimental campaign includes direct measurements of the y-ray intensities from the decay of excited states populated in the 95Mo(n,y) and 95Mo(d,py) reactions.

  13. Adaptive surrogate modeling for response surface approximations with application to bayesian inference

    KAUST Repository

    Prudhomme, Serge

    2015-09-17

    Parameter estimation for complex models using Bayesian inference is usually a very costly process as it requires a large number of solves of the forward problem. We show here how the construction of adaptive surrogate models using a posteriori error estimates for quantities of interest can significantly reduce the computational cost in problems of statistical inference. As surrogate models provide only approximations of the true solutions of the forward problem, it is nevertheless necessary to control these errors in order to construct an accurate reduced model with respect to the observables utilized in the identification of the model parameters. Effectiveness of the proposed approach is demonstrated on a numerical example dealing with the Spalart–Allmaras model for the simulation of turbulent channel flows. In particular, we illustrate how Bayesian model selection using the adapted surrogate model in place of solving the coupled nonlinear equations leads to the same quality of results while requiring fewer nonlinear PDE solves.

  14. Calibration of an agricultural-hydrological model (RZWQM2) using surrogate global optimization

    Science.gov (United States)

    Xi, Maolong; Lu, Dan; Gui, Dongwei; Qi, Zhiming; Zhang, Guannan

    2017-01-01

    Robust calibration of an agricultural-hydrological model is critical for simulating crop yield and water quality and making reasonable agricultural management. However, calibration of the agricultural-hydrological system models is challenging because of model complexity, the existence of strong parameter correlation, and significant computational requirements. Therefore, only a limited number of simulations can be allowed in any attempt to find a near-optimal solution within an affordable time, which greatly restricts the successful application of the model. The goal of this study is to locate the optimal solution of the Root Zone Water Quality Model (RZWQM2) given a limited simulation time, so as to improve the model simulation and help make rational and effective agricultural-hydrological decisions. To this end, we propose a computationally efficient global optimization procedure using sparse-grid based surrogates. We first used advanced sparse grid (SG) interpolation to construct a surrogate system of the actual RZWQM2, and then we calibrate the surrogate model using the global optimization algorithm, Quantum-behaved Particle Swarm Optimization (QPSO). As the surrogate model is a polynomial with fast evaluation, it can be efficiently evaluated with a sufficiently large number of times during the optimization, which facilitates the global search. We calibrate seven model parameters against five years of yield, drain flow, and NO3-N loss data from a subsurface-drained corn-soybean field in Iowa. Results indicate that an accurate surrogate model can be created for the RZWQM2 with a relatively small number of SG points (i.e., RZWQM2 runs). Compared to the conventional QPSO algorithm, our surrogate-based optimization method can achieve a smaller objective function value and better calibration performance using a fewer number of expensive RZWQM2 executions, which greatly improves computational efficiency.

  15. Multimission Fuel-Burn Minimization in Aircraft Design: A Surrogate-Modeling Approach

    Science.gov (United States)

    Liem, Rhea Patricia

    Aerodynamic shape and aerostructural design optimizations that maximize the performance at a single flight condition result in designs with unacceptable off-design performance. While considering multiple flight conditions in the optimization improves the robustness of the designs, there is a need to develop a rational strategy for choosing the flight conditions and their relative emphases such that multipoint optimizations reflect the true objective function. In addition, there is a need to consider uncertain missions and flight conditions. In this thesis, the strategies to formulate the multipoint objective functions for aerodynamic shape and aerostructural optimization are presented. To determine the flight conditions and their corresponding weights, a novel surrogate-based mission analysis is developed to efficiently analyze hundreds of actual mission data to emulate their flight condition distribution. Using accurate and reliable surrogate models to approximate the aerodynamic coefficients used in the analysis makes this procedure computationally tractable. A mixture of experts (ME) approach is developed to overcome the limitations of conventional surrogate models in modeling the complex transonic drag profile. The ME approach combines multiple surrogate models probabilistically based on the divide-andconquer strategy. Using this model in the mission analysis significantly improves the range estimation accuracy, as compared to other conventional surrogate models. As expected, the multipoint aerodynamic shape and aerostructural optimizations demonstrate a consistent drag reduction, instead of the localized improvement by the single-point optimizations. The improved robustness in the multipoint optimized designs was also observed in terms of the improved range performance and more consistent fuel-burn reduction across the different missions. The results presented in this thesis show that the surrogate-model-assisted multipoint optimization produces a robust

  16. Two-dimensional surrogate contact modeling for computationally efficient dynamic simulation of total knee replacements.

    Science.gov (United States)

    Lin, Yi-Chung; Haftka, Raphael T; Queipo, Nestor V; Fregly, Benjamin J

    2009-04-01

    Computational speed is a major limiting factor for performing design sensitivity and optimization studies of total knee replacements. Much of this limitation arises from extensive geometry calculations required by contact analyses. This study presents a novel surrogate contact modeling approach to address this limitation. The approach involves fitting contact forces from a computationally expensive contact model (e.g., a finite element model) as a function of the relative pose between the contacting bodies. Because contact forces are much more sensitive to displacements in some directions than others, standard surrogate sampling and modeling techniques do not work well, necessitating the development of special techniques for contact problems. We present a computational evaluation and practical application of the approach using dynamic wear simulation of a total knee replacement constrained to planar motion in a Stanmore machine. The sample points needed for surrogate model fitting were generated by an elastic foundation (EF) contact model. For the computational evaluation, we performed nine different dynamic wear simulations with both the surrogate contact model and the EF contact model. In all cases, the surrogate contact model accurately reproduced the contact force, motion, and wear volume results from the EF model, with computation time being reduced from 13 min to 13 s. For the practical application, we performed a series of Monte Carlo analyses to determine the sensitivity of predicted wear volume to Stanmore machine setup issues. Wear volume was highly sensitive to small variations in motion and load inputs, especially femoral flexion angle, but not to small variations in component placements. Computational speed was reduced from an estimated 230 h to 4 h per analysis. Surrogate contact modeling can significantly improve the computational speed of dynamic contact and wear simulations of total knee replacements and is appropriate for use in design sensitivity

  17. Surrogate analysis and index developer (SAID) tool and real-time data dissemination utilities

    Science.gov (United States)

    Domanski, Marian M.; Straub, Timothy D.; Wood, Molly S.; Landers, Mark N.; Wall, Gary R.; Brady, Steven J.

    2015-01-01

    The use of acoustic and other parameters as surrogates for suspended-sediment concentrations (SSC) in rivers has been successful in multiple applications across the Nation. Critical to advancing the operational use of surrogates are tools to process and evaluate the data along with the subsequent development of regression models from which real-time sediment concentrations can be made available to the public. Recent developments in both areas are having an immediate impact on surrogate research, and on surrogate monitoring sites currently in operation. The Surrogate Analysis and Index Developer (SAID) standalone tool, under development by the U.S. Geological Survey (USGS), assists in the creation of regression models that relate response and explanatory variables by providing visual and quantitative diagnostics to the user. SAID also processes acoustic parameters to be used as explanatory variables for suspended-sediment concentrations. The sediment acoustic method utilizes acoustic parameters from fixed-mount stationary equipment. The background theory and method used by the tool have been described in recent publications, and the tool also serves to support sediment-acoustic-index methods being drafted by the multi-agency Sediment Acoustic Leadership Team (SALT), and other surrogate guidelines like USGS Techniques and Methods 3-C4 for turbidity and SSC. The regression models in SAID can be used in utilities that have been developed to work with the USGS National Water Information System (NWIS) and for the USGS National Real-Time Water Quality (NRTWQ) Web site. The real-time dissemination of predicted SSC and prediction intervals for each time step has substantial potential to improve understanding of sediment-related water-quality and associated engineering and ecological management decisions.

  18. Effectiveness of external respiratory surrogates for in vivo liver motion estimation

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Kai-Hsiang; Ho, Ming-Chih; Yeh, Chi-Chuan; Chen, Yu-Chien; Lian, Feng-Li; Lin, Win-Li; Yen, Jia-Yush; Chen, Yung-Yaw [Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Department of Surgery, National Taiwan University Hospital and College of Medicine, National Taiwan University, Taipei 10041, Taiwan (China); Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan (China); Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Biomedical Engineering, National Taiwan University, Taipei 10041, Taiwan (China); Department of Mechanical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Department of Electrical Engineering and Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei 10617, Taiwan (China)

    2012-08-15

    Purpose: Due to low frame rate of MRI and high radiation damage from fluoroscopy and CT, liver motion estimation using external respiratory surrogate signals seems to be a better approach to track liver motion in real-time for liver tumor treatments in radiotherapy and thermotherapy. This work proposes a liver motion estimation method based on external respiratory surrogate signals. Animal experiments are also conducted to investigate related issues, such as the sensor arrangement, multisensor fusion, and the effective time period. Methods: Liver motion and abdominal motion are both induced by respiration and are proved to be highly correlated. Contrary to the difficult direct measurement of the liver motion, the abdominal motion can be easily accessed. Based on this idea, our study is split into the model-fitting stage and the motion estimation stage. In the first stage, the correlation between the surrogates and the liver motion is studied and established via linear regression method. In the second stage, the liver motion is estimated by the surrogate signals with the correlation model. Animal experiments on cases of single surrogate signal, multisurrogate signals, and long-term surrogate signals are conducted and discussed to verify the practical use of this approach. Results: The results show that the best single sensor location is at the middle of the upper abdomen, while multisurrogate models are generally better than the single ones. The estimation error is reduced from 0.6 mm for the single surrogate models to 0.4 mm for the multisurrogate models. The long-term validity of the estimation models is quite satisfactory within the period of 10 min with the estimation error less than 1.4 mm. Conclusions: External respiratory surrogate signals from the abdomen motion produces good performance for liver motion estimation in real-time. Multisurrogate signals enhance estimation accuracy, and the estimation model can maintain its accuracy for at least 10 min. This

  19. Religion and Spirituality in Surrogate Decision Making for Hospitalized Older Adults.

    Science.gov (United States)

    Geros-Willfond, Kristin N; Ivy, Steven S; Montz, Kianna; Bohan, Sara E; Torke, Alexia M

    2016-06-01

    We conducted semi-structured interviews with 46 surrogate decision makers for hospitalized older adults to characterize the role of spirituality and religion in decision making. Three themes emerged: (1) religion as a guide to decision making, (2) control, and (3) faith, death and dying. For religious surrogates, religion played a central role in end of life decisions. There was variability regarding whether God or humans were perceived to be in control; however, beliefs about control led to varying perspectives on acceptance of comfort-focused treatment. We conclude that clinicians should attend to religious considerations due to their impact on decision making.

  20. A Bayesian Surrogate Model for Rapid Time Series Analysis and Application to Exoplanet Observations

    CERN Document Server

    Ford, Eric B; Veras, Dimitri

    2011-01-01

    We present a Bayesian surrogate model for the analysis of periodic or quasi-periodic time series data. We describe a computationally efficient implementation that enables Bayesian model comparison. We apply this model to simulated and real exoplanet observations. We discuss the results and demonstrate some of the challenges for applying our surrogate model to realistic exoplanet data sets. In particular, we find that analyses of real world data should pay careful attention to the effects of uneven spacing of observations and the choice of prior for the "jitter" parameter.

  1. Surrogate pregnancy in a patient who underwent radical hysterectomy and bilateral transposition of ovaries.

    Science.gov (United States)

    Azem, Foad; Yovel, Israel; Wagman, Israel; Kapostiansky, Rita; Lessing, Joseph B; Amit, Ami

    2003-05-01

    To evaluate IVF-surrogate pregnancy in a patient with ovarian transposition after radical hysterectomy for carcinoma of the cervix. Case report. A maternity hospital in Tel Aviv that is a major tertiary care and referral center. A 29-year-old woman who underwent Wertheim's hysterectomy for carcinoma of the uterine cervix and ovarian transposition before total pelvic irradiation. Standard IVF treatment, transabdominal oocyte retrieval, and transfer to surrogate mother. Outcome of IVF cycle. A twin pregnancy in the first cycle. This is the second reported case of controlled ovarian stimulation and oocyte retrieval performed on a transposed ovary.

  2. Initial Results from the Third Round of Remediated Nitrate Salt Surrogate Formulation and Testing

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Geoffrey Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Leonard, Philip [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hartline, Ernest Leon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tian, Hongzhao [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-04-20

    High explosives science and technology (M-7) is currently working on the third round of formulation and testing of Remediated nitrate salt (RNS) surrogates. This report summarizes the calorimetry results from the 15% sWheat mixtures. All formulation and testing was carried out according to PLAN-TA9-2443 Rev B, "Remediated Nitrate Salt (RNS) surrogate formulation and testing standard procedure", released February 16, 2016. Results from the first and second rounds of formulation and testing were documented in memoranda M7-16-6042 and M7-16-6053.

  3. Using serum urate as a validated surrogate end point for flares in patients with gout

    DEFF Research Database (Denmark)

    Morillon, Melanie B; Stamp, Lisa; Taylor, William;

    2016-01-01

    INTRODUCTION: Gout is the most common inflammatory arthritis in men over 40 years of age. Long-term urate-lowering therapy is considered a key strategy for effective gout management. The primary outcome measure for efficacy in clinical trials of urate-lowering therapy is serum urate levels......, effectively acting as a surrogate for patient-centred outcomes such as frequency of gout attacks or pain. Yet it is not clearly demonstrated that the strength of the relationship between serum urate and clinically relevant outcomes is sufficiently strong for serum urate to be considered an adequate surrogate...

  4. Effect of a Disease-Specific Planning Intervention on Surrogate Understanding of Patient Goals for Future Medical Treatment

    Science.gov (United States)

    Kirchhoff, Karin T.; Hammes, Bernard J.; Kehl, Karen A.; Briggs, Linda A.; Brown, Roger L.

    2010-01-01

    Context Patients with life-limiting illnesses, and their families, struggle with complex treatment decisions as these patients approach the last few years of life. Surrogates often do not clearly understand the patient's goals for future medical treatments. Objectives To determine if a disease-specific planning process can improve surrogate understanding of such patient goals for future, medical treatments. Design, Setting, and Participants A multisite randomized controlled trial conducted between January 1, 2004 and July 31, 2007 in 6 outpatient clinics of large community or university health systems in 3 Wisconsin cities. Subjects were patients with either chronic congestive heart failure or chronic renal disease and their surrogate decision makers. Participants had to be competent, English-speaking adults at least 18 years of age. Intervention Trained health professionals conducted a structured, patient-centered interview intended to promote informed decision making and to result in the completion of a document clarifying the goals of the patient with regard to four disease-specific health outcome situations and to the degree of decision-making latitude granted to the surrogate. Measurements Surrogate understanding of patient goals for care with regard to four expected, disease-specific outcomes situations and of the degree of surrogate latitude in decision making. Results Three hundred thirteen patient-surrogate pairs completed the study. As measured by Kappa (κ) scores and in all four situations and in the degree of latitude, intervention group surrogates demonstrated a significantly higher degree of understanding of patient goals than control group surrogates. Intervention group κ scores ranged from 0.61 to 0.78, while control group κ scores ranged from 0.07 to 0.28. Conclusion Surrogates in the intervention group had a significantly better understanding of patient goals and preferences than surrogates in the control group. This finding is the first step

  5. Doubt and belief in physicians' ability to prognosticate during critical illness: the perspective of surrogate decision makers.

    Science.gov (United States)

    Zier, Lucas S; Burack, Jeffrey H; Micco, Guy; Chipman, Anne K; Frank, James A; Luce, John M; White, Douglas B

    2008-08-01

    Although discussing a prognosis is a duty of physicians caring for critically ill patients, little is known about surrogate decision-makers' beliefs about physicians' ability to prognosticate. We sought to determine: 1) surrogates' beliefs about whether physicians can accurately prognosticate for critically ill patients; and 2) how individuals use prognostic information in their role as surrogate decision-makers. Multicenter study in intensive care units of a public hospital, a tertiary care hospital, and a veterans' hospital. We conducted semistructured interviews with 50 surrogate decision-makers of critically ill patients. We analyzed the interview transcripts using grounded theory methods to inductively develop a framework to describe surrogates' beliefs about physicians' ability to prognosticate. Validation methods included triangulation by multidisciplinary analysis and member checking. Overall, 88% (44 of 50) of surrogates expressed doubt about physicians' ability to prognosticate for critically ill patients. Four distinct themes emerged that explained surrogates' doubts about prognostic accuracy: a belief that God could alter the course of the illness, a belief that predicting the future is inherently uncertain, prior experiences where physicians' prognostications were inaccurate, and experiences with prognostication during the patient's intensive care unit stay. Participants also identified several factors that led to belief in physicians' prognostications, such as receiving similar prognostic estimates from multiple physicians and prior experiences with accurate prognostication. Surrogates' doubts about prognostic accuracy did not prevent them from wanting prognostic information. Instead, most surrogate decision-makers view physicians' prognostications as rough estimates that are valuable in informing decisions, but are not determinative. Surrogates identified the act of prognostic disclosure as a key step in preparing emotionally and practically for the

  6. Mathematical concepts

    CERN Document Server

    Jost, Jürgen

    2015-01-01

    The main intention of this book is to describe and develop the conceptual, structural and abstract thinking of mathematics. Specific mathematical structures are used to illustrate the conceptual approach; providing a deeper insight into mutual relationships and abstract common features. These ideas are carefully motivated, explained and illustrated by examples so that many of the more technical proofs can be omitted. The book can therefore be used: ·         simply as an overview of the panorama of mathematical structures and the relations between them, to be supplemented by more detailed texts whenever you want to acquire a working knowledge of some structure ·         by itself as a first introduction to abstract mathematics ·         together with existing textbooks, to put their results into a more general perspective ·         to gain a new and hopefully deeper perspective after having studied such textbooks Mathematical Concepts has a broader scope and is less detaile...

  7. Definitions and validation criteria for biomarkers and surrogate endpoints: development and testing of a quantitative hierarchical levels of evidence schema

    DEFF Research Database (Denmark)

    Lassere, Marissa N; Johnson, Kent R; Boers, Maarten

    2007-01-01

    OBJECTIVE: There are clear advantages to using biomarkers and surrogate endpoints, but concerns about clinical and statistical validity and systematic methods to evaluate these aspects hinder their efficient application. Our objective was to review the literature on biomarkers and surrogates to d...

  8. An Artificial Turf-Based Surrogate Surface Collector for the Direct Measurement of Atmospheric Mercury Dry Deposition

    Science.gov (United States)

    This paper describes the development of a new artificial turf surrogate surface (ATSS) sampler for use in the measurement of mercury (Hg) dry deposition. In contrast to many existing surrogate surface designs, the ATSS utilizes a three-dimensional deposition surface that may more...

  9. A conceptual model of family surrogate end-of-life decision-making process in the nursing home setting: goals of care as guiding stars.

    Science.gov (United States)

    Bern-Klug, Mercedes

    2014-01-01

    An increasing proportion of dying is occurring in America's nursing homes (NH). Family members are involved in (and affected by) medical decision-making on behalf of NH residents approaching the end of life, especially when the resident is cognitively impaired. This article proposes an empirically derived conceptual model of the key factors NH family surrogate decision-makers consider when establishing or changing goals of care and the iterative process as applied to the NH setting. This model also establishes the importance of family social role expectations toward their loved one as well as the concept, "stance toward dying," as key in establishing or changing the main goal of care. NH staff and physicians can use the model as a framework for providing information and support to family members. Research is needed to better understand how to prepare staff and settings to support family surrogate decision-makers, in particular around setting goals of care. The model can be generalized beyond nursing homes.

  10. Vertebrates respond differently to human disturbance: implications for the use of a focal species approach

    Science.gov (United States)

    Ficetola, Gentile Francesco; Sacchi, Roberto; Scali, Stefano; Gentilli, Augusto; De Bernardi, Fiorenza; Galeotti, Paolo

    2007-01-01

    Focal species are surrogates assuming that all species under consideration respond similarly to the threatening processes. Focusing management only on a small number of species would improve conditions for other species. However, the across-taxa congruency of the response to threatening processes, and the subsequent efficiency of focal species as surrogates, has seldom been tested. In this study, we evaluated the effects of recreational disturbance and wood structure on the communities of terrestrial vertebrates in the wood patches of a large urban park. We measured two effects of recreation: direct disturbance (people presence) and litter disturbance (effect of trampling). We used multiple techniques to assess the distribution of small mammals, birds, reptiles and amphibians in 44 wood patches. Disturbance and wood maturity influenced the distribution of some species and the species richness of amphibians and reptiles; however, the pattern was not consistent across species within classes or among classes. The performance of focal species as a multi species umbrella was poor. Our results suggest that species specific differences in the response to the same source of disturbance can be strong; these differences can hinder the usefulness of focal species as surrogates and as a management tool.

  11. Permanent pixels : building blocks for the longevity of digital surrogates of historical photographs

    NARCIS (Netherlands)

    Van Horik, M.P.M.

    2005-01-01

    Within the context of long-term access to digital objects in general this dissertation takes the longevity of digital surrogates of historical photographs into consideration. For memory institutes digitisation of analogue source material, such as historical photographs, is an exciting way to open up

  12. PCA-derived respiratory motion surrogates from X-ray angiograms for percutaneous coronary interventions

    NARCIS (Netherlands)

    H. Ma (Hua); G. Dibildox (Gerardo); C. Schultz (Carl); E.S. Regar (Eveline); T.W. van Walsum (Theo)

    2015-01-01

    textabstractPurpose: Intraoperative coronary motion modeling with motion surrogates enables prospective motion prediction in X-ray angiograms (XA) for percutaneous coronary interventions. The motion of coronary arteries is mainly affected by patients breathing and heartbeat. Purpose of our work is t

  13. Testing for nonlinearity in time series: The method of surrogate data

    Energy Technology Data Exchange (ETDEWEB)

    Theiler, J.; Galdrikian, B.; Longtin, A. (Los Alamos National Lab., NM (United States)); Eubank, S.; Farmer, J.D. (Los Alamos National Lab., NM (United States) Santa Fe Inst., NM (United States))

    1991-01-01

    We describe a statistical approach for identifying nonlinearity in time series; in particular, we want to avoid claims of chaos when simpler models (such as linearly correlated noise) can explain the data. The method requires a careful statement of the null hypothesis which characterizes a candidate linear process, the generation of an ensemble of surrogate'' data sets which are similar to the original time series but consistent with the null hypothesis, and the computation of a discriminating statistic for the original and for each of the surrogate data sets. The idea is to test the original time series against the null hypothesis by checking whether the discriminating statistic computed for the original time series differs significantly from the statistics computed for each of the surrogate sets. We present algorithms for generating surrogate data under various null hypotheses, and we show the results of numerical experiments on artificial data using correlation dimension, Lyapunov exponent, and forecasting error as discriminating statistics. Finally, we consider a number of experimental time series -- including sunspots, electroencephalogram (EEG) signals, and fluid convection -- and evaluate the statistical significance of the evidence for nonlinear structure in each case. 56 refs., 8 figs.

  14. Family matters: effects of birth order, culture, and family dynamics on surrogate decision-making.

    Science.gov (United States)

    Su, Christopher T; McMahan, Ryan D; Williams, Brie A; Sharma, Rashmi K; Sudore, Rebecca L

    2014-01-01

    Cultural attitudes about medical decision-making and filial expectations may lead some surrogates to experience stress and family conflict. Thirteen focus groups with racially and ethnically diverse English and Spanish speakers from county and Veterans Affairs hospitals, senior centers, and cancer support groups were conducted to describe participants' experiences making serious or end-of-life decisions for others. Filial expectations and family dynamics related to birth order and surrogate decision-making were explored using qualitative, thematic content analysis, and overarching themes from focus group transcripts were identified. The mean age of the 69 participants was 69 ± 14, and 29% were African American, 26% were white, 26% were Asian or Pacific Islander, and 19% were Latino. Seventy percent of participants engaged in unprompted discussions about birth order and family dynamics. Six subthemes were identified within three overarching categories: communication (unspoken expectations and discussion of death as taboo), emotion (emotional stress and feelings of loneliness), and conflict (family conflict and potential solutions to prevent conflict). These findings suggest that birth order and family dynamics can have profound effects on surrogate stress and coping. Clinicians should be aware of potential unspoken filial expectations for firstborns and help facilitate communication between the patient, surrogate, and extended family to reduce stress and conflict.

  15. ASYMPTOTIC SURROGATE CONSTRAINT METHOD AND ITS CONVERGENCEFOR A CLASS OF SEMI-INFINITE PROGRAMMING

    Institute of Scientific and Technical Information of China (English)

    WanZhongping; WuGuoming

    1999-01-01

    A class of constrained semi infinite minimax problem is transformed into a simpleconstrained problem, by means of discretization decoraposirion and maximum entropy method,making use of surrogate constraint, The paper deals with the convergence of this asymptotic aI-proach method.

  16. Designing a Surrogate Fuel for Gas-to-Liquid Derived Diesel

    DEFF Research Database (Denmark)

    Choudhury, H. A.; Intikhab, S.; Kalakul, Sawitree

    2017-01-01

    loads, diesel fuel surpasses the total hydrocarbon (THC) emissions for both the surrogate and the GTL fuel. No significant variation in CO and CO2 emissions for MI-5, GTL diesel and conventional diesel is observed. Analysis of combustion as well as emission behavior of the fuels helps to understand...

  17. Oxidation of Alkane Rich Gasoline Fuels and their Surrogates in a Motored Engine

    KAUST Repository

    Shankar, Vijai S B

    2015-03-30

    The validation of surrogates formulated using a computational framework by Ahmed et al.[1]for two purely paraffinic gasoline fuels labelled FACE A and FACE C was undertaken in this study. The ability of these surrogate mixtures to be used in modelling LTC engines was accessed by comparison of their low temperature oxidation chemistry with that of the respective parent fuel as well as a PRF based on RON. This was done by testing the surrogate mixtures in a modified Cooperative Fuels Research (CFR) engine running in Controlled Autoignition Mode (CAI) mode. The engine was run at a constant speed of 600 rpm at an equivalence ratio of 0.5 with the intake temperature at 150 °C and a pressure of 98 kPa. The low temperature reactivity of the fuels were studied by varying the compression ratio of the engine from the point were very only small low temperature heat release was observed to a point beyond which auto-ignition of the fuel/air mixture occurred. The apparent heat release rates of different fuels was calculated from the pressure histories using first law analysis and the CA 50 times of the low temperature heat release (LTHR) were compared. The surrogates reproduced the cool flame behavior of the parent fuels better than the PRF across all compression ratios.

  18. Identification of the first surrogate agonists for the G protein-coupled receptor GPR132

    DEFF Research Database (Denmark)

    Shehata, Mohamed A.; Christensen, Hanna Belcik; Isberg, Vignir;

    2015-01-01

    -arrestin recruitment assay, and thereby identified the first disclosed surrogate GPR132 agonist 1 with a potency of 3.4 μM. This constitutes the first available pharmacological tool for the in vitro characterization of the orphan receptor GPR132. The testing of 32 analogs furthermore identified a number of compounds...

  19. A spinal cord surrogate with nanoscale porosity for in vitro simulations of restorative neurosurgical techniques

    Science.gov (United States)

    Gillies, G. T.; Wilhelm, T. D.; Humphrey, J. A. C.; Fillmore, H. L.; Holloway, K. L.; Broaddus, W. C.

    2002-10-01

    The development of strategies for the regrowth of axons through a section of damaged spinal cord could benefit from the availability of an in vitro model in which the potential clinical utility of candidate techniques could be assessed preliminarily. We have designed a spinal cord surrogate for this purpose; it uses 0.6% agarose gel as the parenchymal component and has a fibrous-like longitudinal structure. At this concentration, the pore size distribution of the homogeneous gel ranges from less than 10 nm to more than 1000 nm while the average pore size ranges from 100 to 300 nm. The average pore size is larger than that of the extracellular space in the tissues of the central nervous system, which is of the order of 20 nm. However, the addition of fibres to the surrogate gel model significantly modifies its longitudinal permeability, as assessed by monitoring the distribution of marker dye material during direct infusion into the surrogate. This makes the model useful for evaluating infusion-based techniques that will ultimately be employed for the delivery of growth factors and other agents to the growing axonal processes in injured spinal cord. The role foreseen for this type of surrogate in investigations of the nanomechanics of restorative neurosurgical procedures is discussed.

  20. Determining neutron-capture cross sections via the surrogate reaction technique

    CERN Document Server

    Forssén, C; Escher, J; Hoffman, R D; Kelley, K

    2007-01-01

    Indirect methods play an important role in the determination of nuclear reaction cross sections that are hard to measure directly. In this paper we investigate the feasibility of using the so-called surrogate method to extract neutron-capture cross sections for low energy compound-nuclear reactions in spherical and near-spherical nuclei. We present the surrogate method and develop a statistical nuclear-reaction simulation to explore different approaches to utilize surrogate reaction data. We assess the success of each approach by comparing the extracted cross sections with a predetermined benchmark. In particular, we employ regional systematics of nuclear properties in the 34 <= Z <= 46 region to calculate (n,gamma) cross sections for a series of Zr isotopes, and to simulate a surrogate experiment and the extraction of the desired cross section. We identify one particular approach that may provide very useful estimates of the cross section, and we discuss some of the limitations of the method. General r...

  1. Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE)

    DEFF Research Database (Denmark)

    Vestbo, J; Anderson, W; Coxson, H O

    2008-01-01

    computed tomography, biomarker measurement (in blood, sputum, urine and exhaled breath condensate), health outcomes, body impedance, resting oxygen saturation and 6-min walking distance. Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points is the largest study attempting to better...

  2. Role of Volatility in the Development of JP-8 Surrogates for Diesel Engine Application

    Science.gov (United States)

    2014-01-01

    fuels have also been investigated in different types of experimental systems. Honnet [16] reported that the Aachen (n-decane/1,2,4-trimethylbenzene...indicated that the extinction characteristics of Aachen and modified Aachen (n-dodecane/1,2,4-trimethylbenzene) surrogate fuels agree well with JP-8 in

  3. Refined ambient PM2.5 exposure surrogates and the risk of myocardial infarction

    Science.gov (United States)

    Using a case-crossover study design and conditional logistic regression, we compared the relative odds of transmural (full-wall) myocardial infarction (MI) calculated using exposure surrogates that account for human activity patterns and the indoor transport of ambient PM2....

  4. Thermal Inactivation of Foodborne Enteric Viruses and Their Viral Surrogates in Foods.

    Science.gov (United States)

    Bozkurt, Hayriye; D'Souza, Doris H; Davidson, P Michael

    2015-08-01

    Foodborne viruses, in particular human norovirus and hepatitis A virus, are the most common causes of food-associated infections and foodborne illness outbreaks around the world. Since it is currently not possible to cultivate human noroviruses and the wild-type strain of hepatitis A virus in vitro, the use of a variety of viral surrogates is essential to determine appropriate thermal processing conditions to reduce the risk associated with their contamination of food. Therefore, the objectives of this review are to (i) present pertinent characteristics of enteric foodborne viruses and their viral surrogates, (ii) discuss the viral surrogates currently used in thermal inactivation studies and their significance and value, (iii) summarize available data on thermal inactivation kinetics of enteric viruses, (iv) discuss factors affecting the efficacy of thermal treatment, (v) discuss suggested mechanisms of thermal inactivation, and (vi) provide insights on foodborne enteric viruses and viral surrogates for future studies and industrial applications. The overall goal of this review is to contribute to the development of appropriate thermal processing protocols to ensure safe food for human consumption.

  5. Comparative Numerical Study of Four Biodiesel Surrogates for Application on Diesel 0D Phenomenological Modeling

    Directory of Open Access Journals (Sweden)

    Claude Valery Ngayihi Abbe

    2016-01-01

    Full Text Available To meet more stringent norms and standards concerning engine performances and emissions, engine manufacturers need to develop new technologies enhancing the nonpolluting properties of the fuels. In that sense, the testing and development of alternative fuels such as biodiesel are of great importance. Fuel testing is nowadays a matter of experimental and numerical work. Researches on diesel engine’s fuel involve the use of surrogates, for which the combustion mechanisms are well known and relatively similar to the investigated fuel. Biodiesel, due to its complex molecular configuration, is still the subject of numerous investigations in that area. This study presents the comparison of four biodiesel surrogates, methyl-butanoate, ethyl-butyrate, methyl-decanoate, and methyl-9-decenoate, in a 0D phenomenological combustion model. They were investigated for in-cylinder pressure, thermal efficiency, and NOx emissions. Experiments were performed on a six-cylinder turbocharged DI diesel engine fuelled by methyl ester (MEB and ethyl ester (EEB biodiesel from wasted frying oil. Results showed that, among the four surrogates, methyl butanoate presented better results for all the studied parameters. In-cylinder pressure and thermal efficiency were predicted with good accuracy by the four surrogates. NOx emissions were well predicted for methyl butanoate but for the other three gave approximation errors over 50%.

  6. Inactivation of HAV and norovirus surrogates within raw shellfish and other foods

    Science.gov (United States)

    High pressure processing can inactivate hepatitis A virus, (HAV) and the human norovirus surrogates, feline calicivirus (FCV) and murine norovirus (MNV), in foods such as oysters, strawberries, and green onions. A 5-min 400-Megapascals (MPa) treatment at 5 degrees C and a 1–min 400-MPa treatment at ...

  7. Inactivation of norovirus surrogates on surfaces and raspberries by steam-ultrasound treatment

    DEFF Research Database (Denmark)

    Schultz, Anna Charlotte; Uhrbrand, Katrine; Nørrung, Birgit

    2012-01-01

    treatment that combines pressurized steam and high-power ultrasound (steam-ultrasound) was assessed for its efficacy to inactivate human NoV surrogates: coliphage (MS2), feline calicivirus (FCV), and murine norovirus (MNV) inoculated on plastic surfaces and MS2 inoculated on fresh raspberries. The amounts...

  8. Alternative methods to determine infectivity of Tulane virus: a surrogate for human norovirus

    Science.gov (United States)

    Culturable animal caliciviruses are widely-used as surrogates for human norovirus (HuNoV), which can not replicate in cells. The infectivity of a culturable virus was traditionally determined by plaque assay and/or 50% tissue culture infectious dose (TCID50) assay, both of which are time-consuming ...

  9. Evaluation and Development of Chemical Kinetic Mechanism Reduction Scheme for Biodiesel and Diesel Fuel Surrogates

    DEFF Research Database (Denmark)

    Poon, Hiew Mun; Ng, Hoon Kiat; Gan, Suyin

    2013-01-01

    The aim of this study is to evaluate the existing chemical kinetic mechanism reduction techniques. From here, an appropriate reduction scheme was developed to create compact yet comprehensive surrogate models for both diesel and biodiesel fuels for diesel engine applications. The reduction techni...

  10. A surrogate-based approach for post-genomic partner identification

    Directory of Open Access Journals (Sweden)

    Giordano Tony

    2001-09-01

    Full Text Available Abstract Background Modern drug discovery is concerned with identification and validation of novel protein targets from among the 30,000 genes or more postulated to be present in the human genome. While protein-protein interactions may be central to many disease indications, it has been difficult to identify new chemical entities capable of regulating these interactions as either agonists or antagonists. Results In this paper, we show that peptide complements (or surrogates derived from highly diverse random phage display libraries can be used for the identification of the expected natural biological partners for protein and non-protein targets. Our examples include surrogates isolated against both an extracellular secreted protein (TNFβ and intracellular disease related mRNAs. In each case, surrogates binding to these targets were obtained and found to contain partner information embedded in their amino acid sequences. Furthermore, this information was able to identify the correct biological partners from large human genome databases by rapid and integrated computer based searches. Conclusions Modified versions of these surrogates should provide agents capable of modifying the activity of these targets and enable one to study their involvement in specific biological processes as a means of target validation for downstream drug discovery.

  11. Measurement of arterial wall thickness as a surrogate marker for atherosclerosis

    NARCIS (Netherlands)

    de Groot, E; Hovingh, GK; Wiegman, A; Duriez, P; Smit, AJ; Fruchart, JC; Kastelein, JJP

    2004-01-01

    Large observational studies and atherosclerosis regression trials of lipid-modifying pharmacotherapy have established that intima-media thickness of the carotid and femoral arteries, as measured noninvasively by B-mode ultrasound, is a valid surrogate marker for the progression of atherosclerotic di

  12. Space mapping interpolating surrogates for highly optimized EM-based design of microwave devices

    DEFF Research Database (Denmark)

    Bandler, John; Cheng, Qingsha; Dakroury, Sameh;

    2004-01-01

    A powerful optimization algorithm that incorporates Space Mapping (SM) and the new Output Space Mapping (OSM) to yield highly optimized results in a handful of fine model evaluations is presented. The new method employs an SM-based interpolating surrogate (SMIS) framework that aims at matching th...

  13. Differences in surrogate threshold effect estimates between original and simplified correlation-based validation approaches.

    Science.gov (United States)

    Schürmann, Christoph; Sieben, Wiebke

    2016-03-30

    Surrogate endpoint validation has been well established by the meta-analytical correlation-based approach as outlined in the seminal work of Buyse et al. (Biostatistics, 2000). Surrogacy can be assumed if strong associations on individual and study levels can be demonstrated. Alternatively, if an effect on a true endpoint is to be predicted from a surrogate endpoint in a new study, the surrogate threshold effect (STE, Burzykowski and Buyse, Pharmaceutical Statistics, 2006) can be used. In practice, as individual patient data (IPD) are hard to obtain, some authors use only aggregate data and perform simplified regression analyses. We are interested in to what extent such simplified analyses are biased compared with the ones from a full model with IPD. To this end, we conduct a simulation study with IPD and compute STEs from full and simplified analyses for varying data situations in terms of number of studies, correlations, variances and so on. In the scenarios considered, we show that, for normally distributed patient data, STEs derived from ordinary (weighted) linear regression generally underestimate STEs derived from the original model, whereas meta-regression often results in overestimation. Therefore, if individual data cannot be obtained, STEs from meta-regression may be used as conservative alternatives, but ordinary (weighted) linear regression should not be used for surrogate endpoint validation. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Refined ambient PM2.5 exposure surrogates and the risk of myocardial infarction

    Science.gov (United States)

    Using a case-crossover study design and conditional logistic regression, we compared the relative odds of transmural (full-wall) myocardial infarction (MI) calculated using exposure surrogates that account for human activity patterns and the indoor transport of ambient PM2....

  15. Evidence against the use of surrogates for biomonitoring of Neotropical floodplains

    NARCIS (Netherlands)

    Padial, A.A.; Declerck, S.A.J.; De Meester, L.; Bonecker, C.C.; Lansac-Toha, F.A.; Rodrigues, L.C.; Takeda, A.; Train, S.; Velho, L.F.M.; Bini, L.M.S

    2012-01-01

    1. Community concordance measures the level of association between the compositional patterns shown by two groups of organisms. If strong community concordance occurs, one group could be used as a surrogate for another in conservation planning and biodiversity monitoring. In this study, we evaluated

  16. Atmospheric cold plasma iactivation of norovirus surrogates and native microbiota on blueberries

    Science.gov (United States)

    Cold plasma (CP) is an emerging, novel, nonthermal technology that can be used for surface decontamination of foods. This study investigated CP technology for the nonthermal inactivation of the human norovirus surrogates, Tulane virus (TV) and Murine Norovirus (MNV), as well as for background microb...

  17. Ovulation Statuses of Surrogate Gilts Are Associated with the Efficiency of Excellent Pig Cloning.

    Science.gov (United States)

    Huan, Yanjun; Hu, Kui; Xie, Bingteng; Shi, Yongqian; Wang, Feng; Zhou, Yang; Liu, Shichao; Huang, Bo; Zhu, Jiang; Liu, Zhongfeng; He, Yilong; Li, Jingyu; Kong, Qingran; Liu, Zhonghua

    2015-01-01

    Somatic cell nuclear transfer (SCNT) is an assisted reproductive technique that can produce multiple copies of excellent livestock. However, low cloning efficiency limits the application of SCNT. In this study, we systematically investigated the major influencing factors related to the overall cloning efficiency in pigs. Here, 13620 cloned embryos derived from excellent pigs were transferred into 79 surrogate gilts, and 119 live cloned piglets were eventually generated. During cloning, group of cloned embryos derived from excellent Landrace or Large white pigs presented no significant differences of cleavage and blastocyst rates, blastocyst cell numbers, surrogate pregnancy and delivery rates, average numbers of piglets born and alive and cloning efficiencies, and group of 101-150, 151-200 or 201-250 cloned embryos transferred per surrogate also displayed a similar developmental efficiency. When estrus stage of surrogate gilts was compared, group of embryo transfer on Day 2 of estrus showed significantly higher pregnancy rate, delivery rate, average number of piglets born, average alive piglet number or cloning efficiency than group on Day 1, Day 3, Day 4 or Day 5, respectively (Pcloning efficiency (Pcloning efficiency. And more, follicle puncture for preovulation, not transfer position shallowed for preovulation or deepened for postovulation, significantly improved the average number of piglets alive and cloning efficiency (Pcloning efficiency of excellent pigs, and follicle puncture, not transfer position change, improved cloning efficiency. This work would have important implications in preserving and breeding excellent livestock and improving the overall cloning efficiency.

  18. Electrochemical reduction of CerMet fuels for transmutation using surrogate CeO2-Mo pellets

    Science.gov (United States)

    Claux, B.; Souček, P.; Malmbeck, R.; Rodrigues, A.; Glatz, J.-P.

    2017-08-01

    One of the concepts chosen for the transmutation of minor actinides in Accelerator Driven Systems or fast reactors proposes the use of fuels and targets containing minor actinides oxides embedded in an inert matrix either composed of molybdenum metal (CerMet fuel) or of ceramic magnesium oxide (CerCer fuel). Since the sufficient transmutation cannot be achieved in a single step, it requires multi-recycling of the fuel including recovery of the not transmuted minor actinides. In the present work, a pyrochemical process for treatment of Mo metal inert matrix based CerMet fuels is studied, particularly the electroreduction in molten chloride salt as a head-end step required prior the main separation process. At the initial stage, different inactive pellets simulating the fuel containing CeO2 as minor actinide surrogates were examined. The main studied parameters of the process efficiency were the porosity and composition of the pellets and the process parameters as current density and passed charge. The results indicated the feasibility of the process, gave insight into its limiting parameters and defined the parameters for the future experiment on minor actinide containing material.

  19. Thinking about the patient's wishes: practical wisdom of discharge planning nurses in assisting surrogate decision-making.

    Science.gov (United States)

    Kageyama, Yoko; Asano, Midori

    2017-01-31

    The accelerating trend towards shorter hospital stays in Japan has made modes of decision-making essential for effective patient transition from the hospital to recuperation in the regional community, and the ageing of the population has brought a rise in surrogate decision-making by the families of patients lacking decision-making ('self-decision') capacity. To verbalise and elucidate the practical wisdom of discharge planning nurses by focusing on the perceptions and judgements, they apply in practice and describing their methodology in concrete terms. Participants were six discharge planning nurses and one person with previous experience as a discharge planning nurse, all working at discharge planning departments of acute care hospitals. Separate, semi-structured, interactive interviews were conducted with each participant. The study design was qualitative descriptive in form with qualitative content analysis. All participants provided written informed consent to participate in the study, which was approved by the study institution. Three concepts were extracted as the basis for discharge planning nurses' perception and judgement at acute care hospitals: working for mutual envisionment of the available postdischarge options; helping the family act as spokesperson(s) for the patient's wishes; and understanding the family inclusive of the patient as a relationship of strongly interaffecting interests. The practical wisdom of the nurse, working in mutual envisionment with the family, and collaborative decision-making through discussion with those who know the patient, leads to rational discharge assistance. © 2017 Nordic College of Caring Science.

  20. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success

    Science.gov (United States)

    Pogue, Brian W.; Elliott, Jonathan T.; Kanick, Stephen C.; Davis, Scott C.; Samkoe, Kimberley S.; Maytin, Edward V.; Pereira, Stephen P.; Hasan, Tayyaba

    2016-04-01

    Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment

  1. Revisiting photodynamic therapy dosimetry: reductionist & surrogate approaches to facilitate clinical success.

    Science.gov (United States)

    Pogue, Brian W; Elliott, Jonathan T; Kanick, Stephen C; Davis, Scott C; Samkoe, Kimberley S; Maytin, Edward V; Pereira, Stephen P; Hasan, Tayyaba

    2016-04-01

    Photodynamic therapy (PDT) can be a highly complex treatment, with many parameters influencing treatment efficacy. The extent to which dosimetry is used to monitor and standardize treatment delivery varies widely, ranging from measurement of a single surrogate marker to comprehensive approaches that aim to measure or estimate as many relevant parameters as possible. Today, most clinical PDT treatments are still administered with little more than application of a prescribed drug dose and timed light delivery, and thus the role of patient-specific dosimetry has not reached widespread clinical adoption. This disconnect is at least partly due to the inherent conflict between the need to measure and understand multiple parameters in vivo in order to optimize treatment, and the need for expedience in the clinic and in the regulatory and commercialization process. Thus, a methodical approach to selecting primary dosimetry metrics is required at each stage of translation of a treatment procedure, moving from complex measurements to understand PDT mechanisms in pre-clinical and early phase I trials, towards the identification and application of essential dose-limiting and/or surrogate measurements in phase II/III trials. If successful, identifying the essential and/or reliable surrogate dosimetry measurements should help facilitate increased adoption of clinical PDT. In this paper, examples of essential dosimetry points and surrogate dosimetry tools that may be implemented in phase II/III trials are discussed. For example, the treatment efficacy as limited by light penetration in interstitial PDT may be predicted by the amount of contrast uptake in CT, and so this could be utilized as a surrogate dosimetry measurement to prescribe light doses based upon pre-treatment contrast. Success of clinical ALA-based skin lesion treatment is predicted almost uniquely by the explicit or implicit measurements of photosensitizer and photobleaching, yet the individualization of treatment

  2. Quantitative GPCR and ion channel transcriptomics in primary alveolar macrophages and macrophage surrogates

    Directory of Open Access Journals (Sweden)

    Groot-Kormelink Paul J

    2012-10-01

    Full Text Available Abstract Background Alveolar macrophages are one of the first lines of defence against invading pathogens and play a central role in modulating both the innate and acquired immune systems. By responding to endogenous stimuli within the lung, alveolar macrophages contribute towards the regulation of the local inflammatory microenvironment, the initiation of wound healing and the pathogenesis of viral and bacterial infections. Despite the availability of protocols for isolating primary alveolar macrophages from the lung these cells remain recalcitrant to expansion in-vitro and therefore surrogate cell types, such as monocyte derived macrophages and phorbol ester-differentiated cell lines (e.g. U937, THP-1, HL60 are frequently used to model macrophage function. Methods The availability of high throughput gene expression technologies for accurate quantification of transcript levels enables the re-evaluation of these surrogate cell types for use as cellular models of the alveolar macrophage. Utilising high-throughput TaqMan arrays and focussing on dynamically regulated families of integral membrane proteins, we explore the similarities and differences in G-protein coupled receptor (GPCR and ion channel expression in alveolar macrophages and their widely used surrogates. Results The complete non-sensory GPCR and ion channel transcriptome is described for primary alveolar macrophages and macrophage surrogates. The expression of numerous GPCRs and ion channels whose expression were hitherto not described in human alveolar macrophages are compared across primary macrophages and commonly used macrophage cell models. Several membrane proteins known to have critical roles in regulating macrophage function, including CXCR6, CCR8 and TRPV4, were found to be highly expressed in macrophages but not expressed in PMA-differentiated surrogates. Conclusions The data described in this report provides insight into the appropriate choice of cell models for

  3. Mitigating Errors in External Respiratory Surrogate-Based Models of Tumor Position

    Energy Technology Data Exchange (ETDEWEB)

    Malinowski, Kathleen T. [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); McAvoy, Thomas J. [Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States); Department of Chemical and Biomolecular Engineering and Institute of Systems Research, University of Maryland, College Park, MD (United States); George, Rohini [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Dieterich, Sonja [Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA (United States); D' Souza, Warren D., E-mail: wdsou001@umaryland.edu [Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD (United States); Fischell Department of Bioengineering, University of Maryland, College Park, MD (United States)

    2012-04-01

    Purpose: To investigate the effect of tumor site, measurement precision, tumor-surrogate correlation, training data selection, model design, and interpatient and interfraction variations on the accuracy of external marker-based models of tumor position. Methods and Materials: Cyberknife Synchrony system log files comprising synchronously acquired positions of external markers and the tumor from 167 treatment fractions were analyzed. The accuracy of Synchrony, ordinary-least-squares regression, and partial-least-squares regression models for predicting the tumor position from the external markers was evaluated. The quantity and timing of the data used to build the predictive model were varied. The effects of tumor-surrogate correlation and the precision in both the tumor and the external surrogate position measurements were explored by adding noise to the data. Results: The tumor position prediction errors increased during the duration of a fraction. Increasing the training data quantities did not always lead to more accurate models. Adding uncorrelated noise to the external marker-based inputs degraded the tumor-surrogate correlation models by 16% for partial-least-squares and 57% for ordinary-least-squares. External marker and tumor position measurement errors led to tumor position prediction changes 0.3-3.6 times the magnitude of the measurement errors, varying widely with model algorithm. The tumor position prediction errors were significantly associated with the patient index but not with the fraction index or tumor site. Partial-least-squares was as accurate as Synchrony and more accurate than ordinary-least-squares. Conclusions: The accuracy of surrogate-based inferential models of tumor position was affected by all the investigated factors, except for the tumor site and fraction index.

  4. Compositional effects on PAH and soot formation in counterflow diffusion flames of gasoline surrogate fuels

    KAUST Repository

    Park, Sungwoo

    2017-02-05

    Gasoline surrogate fuels are widely used to understand the fundamental combustion properties of complex refinery gasoline fuels. In this study, the compositional effects on polycyclic aromatic hydrocarbons (PAHs) and soot formation were investigated experimentally for gasoline surrogate mixtures comprising n-heptane, iso-octane, and toluene in counterflow diffusion flames. A comprehensive kinetic model for the gasoline surrogate mixtures was developed to accurately predict the fuel oxidation along with the formation of PAHs and soot in flames. This combined model was first tested against ignition delay times and laminar burning velocities data. The proposed model for the formation and growth of PAHs up to coronene (C24H12) was based on previous studies and was tested against existing and present new experimental data. Additionally, in the accompanied soot model, PAHs with sizes larger than (including) pyrene were used for the inception of soot particles, followed by particle coagulations and PAH condensation/chemical reactions on soot surfaces. The major pathways for the formation of PAHs were also identified for the surrogate mixtures. The model accurately captures the synergistic PAH formation characteristics observed experimentally for n-heptane/toluene and iso-octane/toluene binary mixtures. Furthermore, the present experimental and modeling results also elucidated different trends in the formation of larger PAHs and soot between binary n-heptane/iso-octane and ternary n-heptane/iso-octane/toluene mixtures. Propargyl radicals (C3H3) were shown to be important in the formation and growth of PAHs for n-heptane/iso-octane mixtures when the iso-octane concentration increased; however, reactions involving benzyl radicals (C6H5CH2) played a significant role in the formation of PAHs for n-heptane/iso-octane/toluene mixtures. These results indicated that the formation of PAHs and subsequently soot was strongly affected by the composition of gasoline surrogate mixtures.

  5. A case study on the use of appropriate surrogates for antecedent moisture conditions (AMCs

    Directory of Open Access Journals (Sweden)

    G. A. Ali

    2010-06-01

    Full Text Available While a large number of non-linear hillslope and catchment rainfall-runoff responses have been attributed to the temporal variability in antecedent moisture conditions (AMCs, two problems emerge: 1 the difficulty of measuring AMCs, and 2 the absence of explicit guidelines for the choice of surrogates or proxies for AMCs. This paper aims at determining whether or not multiple surrogates for AMCs should be used in order not to bias our understanding of a system hydrological behaviour. We worked in a small forested catchment, the Hermine, where soil moisture has been measured at 121 different locations at four depths on 16 occasions. Without making any assumption on active processes, we used various linear and nonlinear regression models to evaluate the point-scale temporal relations between actual soil moisture contents and selected meteorological-based surrogates for AMCs. We then mapped the nature of the "best fit" model to identify 1 spatial clusters of soil moisture monitoring sites whose hydrological behaviour was similar, and 2 potential topographic influences on these behaviours. Two conclusions stood out. Firstly, it was shown that the sole reference to AMCs indices traditionally used in catchment hydrology, namely antecedent rainfall amounts summed over periods of seven or ten days, would have led to an incomplete understanding of the Hermine catchment dynamics. Secondly, the relationships between point-scale soil moisture content and surrogates for AMCs were not spatially homogeneous, thus revealing a mosaic of linear and nonlinear catchment "active" and "contributing" sources whose location was often controlled by surface terrain attributes or the topography of a soil-confining layer interface. These results represent a step forward in developing a hydrological conceptual model for the Hermine catchment as they indicate depth-specific processes and spatially-variable triggering conditions. Further investigations are, however, necessary

  6. Surrogate assisted multidisciplinary design optimization for an all-electric GEO satellite

    Science.gov (United States)

    Shi, Renhe; Liu, Li; Long, Teng; Liu, Jian; Yuan, Bin

    2017-09-01

    State-of-the-art all-electric geostationary earth orbit (GEO) satellites use electric thrusters to execute all propulsive duties, which significantly differ from the traditional all-chemical ones in orbit-raising, station-keeping, radiation damage protection, and power budget, etc. Design optimization task of an all-electric GEO satellite is therefore a complex multidisciplinary design optimization (MDO) problem involving unique design considerations. However, solving the all-electric GEO satellite MDO problem faces big challenges in disciplinary modeling techniques and efficient optimization strategy. To address these challenges, we presents a surrogate assisted MDO framework consisting of several modules, i.e., MDO problem definition, multidisciplinary modeling, multidisciplinary analysis (MDA), and surrogate assisted optimizer. Based on the proposed framework, the all-electric GEO satellite MDO problem is formulated to minimize the total mass of the satellite system under a number of practical constraints. Then considerable efforts are spent on multidisciplinary modeling involving geosynchronous transfer, GEO station-keeping, power, thermal control, attitude control, and structure disciplines. Since orbit dynamics models and finite element structural model are computationally expensive, an adaptive response surface surrogate based optimizer is incorporated in the proposed framework to solve the satellite MDO problem with moderate computational cost, where a response surface surrogate is gradually refined to represent the computationally expensive MDA process. After optimization, the total mass of the studied GEO satellite is decreased by 185.3 kg (i.e., 7.3% of the total mass). Finally, the optimal design is further discussed to demonstrate the effectiveness of our proposed framework to cope with the all-electric GEO satellite system design optimization problems. This proposed surrogate assisted MDO framework can also provide valuable references for other all

  7. 'Tissue surrogates' as a model for archival formalin-fixed paraffin-embedded tissues.

    Science.gov (United States)

    Fowler, Carol B; Cunningham, Robert E; O'Leary, Timothy J; Mason, Jeffrey T

    2007-08-01

    High-throughput proteomic studies of archival formalin-fixed paraffin-embedded (FFPE) tissues have the potential to be a powerful tool for examining the clinical course of disease. However, advances in FFPE tissue-based proteomics have been hampered by inefficient methods to extract proteins from archival tissue and by an incomplete knowledge of formaldehyde-induced modifications in proteins. To help address these problems, we have developed a procedure for the formation of 'tissue surrogates' to model FFPE tissues. Cytoplasmic proteins, such as lysozyme or ribonuclease A, at concentrations approaching the protein content in whole cells, are fixed with 10% formalin to form gelatin-like plugs. These plugs have sufficient physical integrity to be processed through graded alcohols, xylene, and embedded in paraffin according to standard histological procedures. In this study, we used tissue surrogates formed from one or two proteins to evaluate extraction protocols for their ability to quantitatively extract proteins from the surrogates. Optimal protein extraction was obtained using a combination of heat, a detergent, and a protein denaturant. The addition of a reducing agent did not improve protein recovery; however, recovery varied significantly with pH. Protein extraction of >80% was observed for pH 4 buffers containing 2% (w/v) sodium dodecyl sulfate (SDS) when heated at 100 degrees C for 20 min, followed by incubation at 60 degrees C for 2 h. SDS-polyacrylamide gel electrophoresis of the extracted proteins revealed that the surrogate extracts contained a mixture of monomeric and multimeric proteins, regardless of the extraction protocol employed. Additionally, protein extracts from surrogates containing carbonic anhydrase:lysozyme (1:2 mol/mol) had disproportionate percentages of lysozyme, indicating that selective protein extraction in complex multiprotein systems may be a concern in proteomic studies of FFPE tissues.

  8. The national Fire and Fire Surrogate study: Effects of fuel reduction methods on forest vegetation structure and fuels

    Science.gov (United States)

    Schwilk, D.W.; Keeley, J.E.; Knapp, E.E.; Mciver, J.; Bailey, J.D.; Fettig, C.J.; Fiedler, C.E.; Harrod, R.J.; Moghaddas, J.J.; Outcalt, K.W.; Skinner, C.N.; Stephens, S.L.; Waldrop, T.A.; Yaussy, D.A.; Youngblood, A.

    2009-01-01

    Changes in vegetation and fuels were evaluated from measurements taken before and after fuel reduction treatments (prescribed fire, mechanical treatments, and the combination of the two) at 12 Fire and Fire Surrogate (FFS) sites located in forests with a surface fire regime across the conterminous United States. To test the relative effectiveness of fuel reduction treatments and their effect on ecological parameters we used an informationtheoretic approach on a suite of 12 variables representing the overstory (basal area and live tree, sapling, and snag density), the understory (seedling density, shrub cover, and native and alien herbaceous species richness), and the most relevant fuel parameters for wildfire damage (height to live crown, total fuel bed mass, forest floor mass, and woody fuel mass). In the short term (one year after treatment), mechanical treatments were more effective at reducing overstory tree density and basal area and at increasing quadratic mean tree diameter. Prescribed fire treatments were more effective at creating snags, killing seedlings, elevating height to live crown, and reducing surface woody fuels. Overall, the response to fuel reduction treatments of the ecological variables presented in this paper was generally maximized by the combined mechanical plus burning treatment. If the management goal is to quickly produce stands with fewer and larger diameter trees, less surface fuel mass, and greater herbaceous species richness, the combined treatment gave the most desirable results. However, because mechanical plus burning treatments also favored alien species invasion at some sites, monitoring and control need to be part of the prescription when using this treatment. ?? 2009 by the Ecological Society of America.

  9. Concept analysis of good death in terminally ill patients.

    Science.gov (United States)

    Granda-Cameron, Clara; Houldin, Arlene

    2012-12-01

    The purpose of this concept analysis of good death was to examine the attributes of a good death and explore the changes of the concept over time and its impact on terminally ill patients. The method used for this analysis was the Rodgers' evolutionary method. A literature search was completed using Medline Ovid and Journal Storage (JSTOR).The findings describe the evolution of the good death concept over time from the prehistoric era followed by premodern, modern, and postmodern times. In addition, information is presented about surrogate terms, attributes, antecedents, and consequences associated with good death followed by analysis and discussion of the findings. General attributes of a good death include pain and symptom management, awareness of death, patient's dignity, family presence, family support, and communication among patient, family, and health care providers.

  10. “RéaNet”, the Internet utilization among surrogates of critically ill patients with sepsis

    Science.gov (United States)

    Porcher, Raphaël; Argaud, Laurent; Piquilloud, Lise; Guitton, Christophe; Tamion, Fabienne; Hraiech, Sami; Mira, Jean-Paul

    2017-01-01

    Context Health-related Internet utilization is common but its use by proxies of critically ill patients is unknown. Our objective was to describe the prevalence and the Internet utilization characteristics among surrogates of critically ill septic patients. We conducted a prospective observational study in French ICUs. Three survey instruments were used to describe ICU organization regarding information delivery, patients and surrogates characteristics. Results 169 surrogates of 146 septic patients hospitalized in 19 ICUs were included. One sixth of ICUs (n = 3, 16%) had their own website. Majority of patients were males (n = 100, 68%), aged 64±1 years old, with a SAPS2 score at 53±17 and required vasopressors (n = 117, 83%), mechanical ventilation (n = 116, 82%). More than one quarter required renal replacement therapy (n = 36, 26%). Majority of surrogates were female, in their fifties. Only one in five knew the word sepsis (n = 27, 16%). Majority of proxies internet users (n = 77; 55%) search on the internet about sepsis. The main motivation was curiosity. Majority of surrogates found the information online reliable, suitable for request and concordant. Prior use of health-related Internet (OR = 20.7 [4.30–100.1]), the presence of a nursing staff during family-physician meetings (OR = 3.33 [1.17–9.53]), a younger patient age (OR = 1.32 [1.01–1.72]) and renal replacement therapy requirement (OR = 2.58 [1.06–6.26]) were associated with health-related Internet use. Neither satisfaction with medical care or information provision, neither presence of anxiety-depression symptoms, were associated with health-related Internet use. Majority of surrogates (N = 76 (52%)) would have like receiving a list of selected websites on sepsis. Conclusions Majority of proxies of critically ill patients with sepsis use Internet to learn more about sepsis. Internet utilization is independent of satisfaction with global ICU care, perceived quality of information delivery by

  11. The NASA Langley Research Center's Unmanned Aerial System Surrogate Research Aircraft

    Science.gov (United States)

    Howell, Charles T., III; Jessup, Artie; Jones, Frank; Joyce, Claude; Sugden, Paul; Verstynen, Harry; Mielnik, John

    2010-01-01

    Research is needed to determine what procedures, aircraft sensors and other systems will be required to allow Unmanned Aerial Systems (UAS) to safely operate with manned aircraft in the National Airspace System (NAS). The NASA Langley Research Center has transformed a Cirrus Design SR22 general aviation (GA) aircraft into a UAS Surrogate research aircraft to serve as a platform for UAS systems research, development, flight testing and evaluation. The aircraft is manned with a Safety Pilot and systems operator that allows for flight operations almost anywhere in the NAS without the need for a Federal Aviation Administration (FAA) Certificate of Authorization (COA). The UAS Surrogate can be controlled from a modular, transportable ground station like a true UAS. The UAS Surrogate is able to file and fly in the NAS with normal traffic and is a better platform for real world UAS research and development than existing vehicles flying in restricted ranges or other sterilized airspace. The Cirrus Design SR22 aircraft is a small, singleengine, four-place, composite-construction aircraft that NASA Langley acquired to support NASA flight-research programs like the Small Aircraft Transportation System (SATS) Project. Systems were installed to support flight test research and data gathering. These systems include: separate research power; multi-function flat-panel displays; research computers; research air data and inertial state sensors; video recording; data acquisition; data-link; S-band video and data telemetry; Common Airborne Instrumentation System (CAIS); Automatic Dependent Surveillance-Broadcast (ADS-B); instrumented surfaces and controls; and a systems operator work station. The transformation of the SR22 to a UAS Surrogate was accomplished in phases. The first phase was to modify the existing autopilot to accept external commands from a research computer that was connected by redundant data-link radios to a ground control station. An electro-mechanical auto

  12. "RéaNet", the Internet utilization among surrogates of critically ill patients with sepsis.

    Science.gov (United States)

    Nguyen, Yên-Lan; Porcher, Raphaël; Argaud, Laurent; Piquilloud, Lise; Guitton, Christophe; Tamion, Fabienne; Hraiech, Sami; Mira, Jean-Paul

    2017-01-01

    Health-related Internet utilization is common but its use by proxies of critically ill patients is unknown. Our objective was to describe the prevalence and the Internet utilization characteristics among surrogates of critically ill septic patients. We conducted a prospective observational study in French ICUs. Three survey instruments were used to describe ICU organization regarding information delivery, patients and surrogates characteristics. 169 surrogates of 146 septic patients hospitalized in 19 ICUs were included. One sixth of ICUs (n = 3, 16%) had their own website. Majority of patients were males (n = 100, 68%), aged 64±1 years old, with a SAPS2 score at 53±17 and required vasopressors (n = 117, 83%), mechanical ventilation (n = 116, 82%). More than one quarter required renal replacement therapy (n = 36, 26%). Majority of surrogates were female, in their fifties. Only one in five knew the word sepsis (n = 27, 16%). Majority of proxies internet users (n = 77; 55%) search on the internet about sepsis. The main motivation was curiosity. Majority of surrogates found the information online reliable, suitable for request and concordant. Prior use of health-related Internet (OR = 20.7 [4.30-100.1]), the presence of a nursing staff during family-physician meetings (OR = 3.33 [1.17-9.53]), a younger patient age (OR = 1.32 [1.01-1.72]) and renal replacement therapy requirement (OR = 2.58 [1.06-6.26]) were associated with health-related Internet use. Neither satisfaction with medical care or information provision, neither presence of anxiety-depression symptoms, were associated with health-related Internet use. Majority of surrogates (N = 76 (52%)) would have like receiving a list of selected websites on sepsis. Majority of proxies of critically ill patients with sepsis use Internet to learn more about sepsis. Internet utilization is independent of satisfaction with global ICU care, perceived quality of information delivery by doctors or the existence of anxiety

  13. Development of Depletion Code Surrogate Models for Uncertainty Propagation in Scenario Studies

    Science.gov (United States)

    Krivtchik, Guillaume; Coquelet-Pascal, Christine; Blaise, Patrick; Garzenne, Claude; Le Mer, Joël; Freynet, David

    2014-06-01

    The result of transition scenario studies, which enable the comparison of different options of the reactor fleet evolution and management of the future fuel cycle materials, allow to perform technical and economic feasibility studies. The COSI code is developed by CEA and used to perform scenario calculations. It allows to model any fuel type, reactor fleet, fuel facility, and permits the tracking of U, Pu, minor actinides and fission products nuclides on a large time scale. COSI is coupled with the CESAR code which performs the depletion calculations based on one-group cross-section libraries and nuclear data. Different types of uncertainties have an impact on scenario studies: nuclear data and scenario assumptions. Therefore, it is necessary to evaluate their impact on the major scenario results. The methodology adopted to propagate these uncertainties throughout the scenario calculations is a stochastic approach. Considering the amount of inputs to be sampled in order to perform a stochastic calculation of the propagated uncertainty, it appears necessary to reduce the calculation time. Given that evolution calculations represent approximately 95% of the total scenario simulation time, an optimization can be done, with the development and implementation of a surrogate models library of CESAR in COSI. The input parameters of CESAR are sampled with URANIE, the CEA uncertainty platform, and for every sample, the isotopic composition after evolution evaluated with CESAR is stored. Then statistical analysis of the input and output tables allow to model the behavior of CESAR on each CESAR library, i.e. building a surrogate model. Several quality tests are performed on each surrogate model to insure the prediction power is satisfying. Afterward, a new routine implemented in COSI reads these surrogate models and using them in replacement of CESAR calculations. A preliminary study of the calculation time gain shows that the use of surrogate models allows stochastic

  14. Fabrication and Characterization of Surrogate TRISO Particles Using 800μm ZrO2 Kernels

    Energy Technology Data Exchange (ETDEWEB)

    Jolly, Brian C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Helmreich, Grant [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cooley, Kevin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dyer, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Terrani, Kurt [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-07-01

    In support of fully ceramic microencapsulated (FCM) fuel development, coating development work is ongoing at Oak Ridge National Laboratory (ORNL) to produce tri-structural isotropic (TRISO) coated fuel particles with both UN kernels and surrogate (uranium-free) kernels. The nitride kernels are used to increase fissile density in these SiC-matrix fuel pellets with details described elsewhere. The surrogate TRISO particles are necessary for separate effects testing and for utilization in the consolidation process development. This report focuses on the fabrication and characterization of surrogate TRISO particles which use 800μm in diameter ZrO2 microspheres as the kernel.

  15. Detailed chemical kinetic mechanism for the oxidation of biodiesel fuels blend surrogate.

    Energy Technology Data Exchange (ETDEWEB)

    Herbinet, O; Pitz, W J; Westbrook, C K

    2009-07-21

    Detailed chemical kinetic mechanisms were developed and used to study the oxidation of two large unsaturated esters: methyl-5-decenoate and methyl-9-decenoate. These models were built from a previous methyl decanoate mechanism and were compared with rapeseed oil methyl esters oxidation experiments in a jet stirred reactor. A comparative study of the reactivity of these three oxygenated compounds was performed and the differences in the distribution of the products of the reaction were highlighted showing the influence of the presence and the position of a double bond in the chain. Blend surrogates, containing methyl decanoate, methyl-5-decenoate, methyl-9-decenoate and n-alkanes, were tested against rapeseed oil methyl esters and methyl palmitate/n-decane experiments. These surrogate models are realistic kinetic tools allowing the study of the combustion of biodiesel fuels in diesel and homogeneous charge compression ignition engines.

  16. Anthropometric surrogates for screening of low birth weight newborns: a community-based study.

    Science.gov (United States)

    Rustagi, Neeti; Prasuna, J G; Taneja, D K

    2012-03-01

    In developing countries, where about 75% of births occur at home or in the community, logistic problems prevent the weighing of every newborn child. This study compares various anthropometric surrogates for identification of low birth weight neonates. A longitudinal community based study was done in an urban resettlement colony and 283 singleton neonates within 7 days of birth were examined for the anthropometric measurements such as head, chest, mid upper arm circumference and foot length as a screening tool for low birth weight. Chest circumference measured within 7 days of birth appeared to be the most appropriate surrogate of low birth weight with highest sensitivity (75.4%), specificity (78.4%), and positive predictive value (48.9%) as compared with other anthropometric parameters. Low birth weight neonates in absence of weighing scales can be early identified by using simple anthropometric measurements for enhanced home-based care and timely referral.

  17. Quantum dynamics of a vibronically coupled linear chain using a surrogate Hamiltonian approach.

    Science.gov (United States)

    Lee, Myeong H; Troisi, Alessandro

    2016-06-07

    Vibronic coupling between the electronic and vibrational degrees of freedom has been reported to play an important role in charge and exciton transport in organic photovoltaic materials, molecular aggregates, and light-harvesting complexes. Explicitly accounting for effective vibrational modes rather than treating them as a thermal environment has been shown to be crucial to describe the effect of vibronic coupling. We present a methodology to study dissipative quantum dynamics of vibronically coupled systems based on a surrogate Hamiltonian approach, which is in principle not limited by Markov approximation or weak system-bath interaction, using a vibronic basis. We apply vibronic surrogate Hamiltonian method to a linear chain system and discuss how different types of relaxation process, intramolecular vibrational relaxation and intermolecular vibronic relaxation, influence population dynamics of dissipative vibronic systems.

  18. Pseudo-periodic surrogate test to sample time series in stochastic softening Duffing oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Gan Chunbiao [Department of Mechanics, CMEE, Zhejiang University, Hangzhou 310027 (China)]. E-mail: cb_gan@zju.edu.cn

    2006-09-11

    Identification of typical noise-contaminated sample response is a hard task in a nonlinear system under stochastic background since irregularity of the sample response may come from measure noise, dynamical noise, or nonlinear effect, etc., and conventional dynamical methods are generally not useful. Here, the pseudo-periodic surrogate algorithm by Small is employed to test the sample time series in the softening Duffing oscillator under the Gaussian white noise excitation. The correlation dimensions of the noisy periodic and the noise-induced chaotic time series of the system are compared with those of their corresponding surrogate data respectively, the leading Lyapunov exponents by Rosenstein's algorithm are also presented for comparison.

  19. Fast surrogate-assisted simulation-driven optimization of compact microwave hybrid couplers

    Science.gov (United States)

    Kurgan, Piotr; Koziel, Slawomir

    2016-07-01

    This work presents a robust methodology for expedited simulation-driven design optimization of compact microwave hybrid couplers. The technique relies on problem decomposition, and a bottom-up design strategy, starting from the level of basic building blocks of the coupler, and finishing with a tuning procedure that exploits a fast surrogate model of the entire structure. The latter is constructed by cascading local response surface approximations of coupler elementary elements. The cross-coupling effects within the structure are neglected in the first stage of the design process; however, they are accounted for in the tuning phase by means of space-mapping correction of the surrogate. The proposed approach is demonstrated through the design of a compact rat-race and two branch-line couplers. In all cases, the computational cost of the optimization process is very low and corresponds to just a few high-fidelity electromagnetic simulations of respective structures. Experimental validation is also provided.

  20. Will higher traffic flow lead to more traffic conflicts? A crash surrogate metric based analysis.

    Science.gov (United States)

    Kuang, Yan; Qu, Xiaobo; Yan, Yadan

    2017-01-01

    In this paper, we aim to examine the relationship between traffic flow and potential conflict risks by using crash surrogate metrics. It has been widely recognized that one traffic flow corresponds to two distinct traffic states with different speeds and densities. In view of this, instead of simply aggregating traffic conditions with the same traffic volume, we represent potential conflict risks at a traffic flow fundamental diagram. Two crash surrogate metrics, namely, Aggregated Crash Index and Time to Collision, are used in this study to represent the potential conflict risks with respect to different traffic conditions. Furthermore, Beijing North Ring III and Next Generation SIMulation Interstate 80 datasets are utilized to carry out case studies. By using the proposed procedure, both datasets generate similar trends, which demonstrate the applicability of the proposed methodology and the transferability of our conclusions.

  1. Adaptive Surrogate Modeling for Response Surface Approximations with Application to Bayesian Inference

    KAUST Repository

    Prudhomme, Serge

    2015-01-07

    The need for surrogate models and adaptive methods can be best appreciated if one is interested in parameter estimation using a Bayesian calibration procedure for validation purposes. We extend here our latest work on error decomposition and adaptive refinement for response surfaces to the development of surrogate models that can be substituted for the full models to estimate the parameters of Reynolds-averaged Navier-Stokes models. The error estimates and adaptive schemes are driven here by a quantity of interest and are thus based on the approximation of an adjoint problem. We will focus in particular to the accurate estimation of evidences to facilitate model selection. The methodology will be illustrated on the Spalart-Allmaras RANS model for turbulence simulation.

  2. Neutron capture surrogate reaction on 75As in inverse kinematics using (d,pγ

    Directory of Open Access Journals (Sweden)

    Smith M.S.

    2010-03-01

    Full Text Available The 75As(d,pγ reaction in inverse kinematics as a surrogate for neutron capture was performed at Oak Ridge National Laboratory using a deuterated plastic target. The intensity of the 165 keV γ-ray from 76As in coincidence with ejected protons, from exciting 76As above the neutron separation energy populating a compound state, was measured. A tight geometry of four segmented germanium clover γ-ray detectors together with eight ORRUBA-type silicon-strip charged-particle detectors was used to optimize geometric acceptance. The preliminary analysis of the 75As experiment, and the eïňČcacy and future plans of the (d,pγ surrogate campaign in inverse kinematics, are discussed.

  3. Determination of Diethyl Phthalate and Polyhexamethylene Guanidine in Surrogate Alcohol from Russia

    Directory of Open Access Journals (Sweden)

    Yulia B. Monakhova

    2011-01-01

    Full Text Available Analytical methods based on spectroscopic techniques were developed and validated for the determination of diethyl phthalate (DEP and polyhexamethylene guanidine (PHMG, which may occur in unrecorded alcohol. Analysis for PHMG was based on UV-VIS spectrophotometry after derivatization with Eosin Y and 1H NMR spectroscopy of the DMSO extract. Analysis of DEP was performed with direct UV-VIS and 1H NMR methods. Multivariate curve resolution and spectra computation methods were used to confirm the presence of PHMG and DEP in the investigated beverages. Of 22 analysed alcohol samples, two contained DEP or PHMG. 1H NMR analysis also revealed the presence of signals of hawthorn extract in three medicinal alcohols used as surrogate alcohol. The simple and cheap UV-VIS methods can be used for rapid screening of surrogate alcohol samples for impurities, while 1H NMR is recommended for specific confirmatory analysis if required.

  4. Spatial network surrogates for disentangling complex system structure from spatial embedding of nodes

    CERN Document Server

    Wiedermann, Marc; Kurths, Jürgen; Donner, Reik V

    2015-01-01

    Networks with nodes embedded in a metric space have gained increasing interest in recent years. The effects of spatial embedding on the networks' structural characteristics, however, are rarely taken into account when studying their macroscopic properties. Here, we propose a hierarchy of null models to generate random surrogates from a given spatially embedded network that can preserve global and local statistics associated with the nodes' embedding in a metric space. Comparing the original network's and the resulting surrogates' global characteristics allows to quantify to what extent these characteristics are already predetermined by the spatial embedding of the nodes and links. We apply our framework to various real-world spatial networks and show that the proposed models capture macroscopic properties of the networks under study much better than standard random network models that do not account for the nodes' spatial embedding. Depending on the actual performance of the proposed null models, the networks...

  5. Efficient stochastic EMC/EMI analysis using HDMR-generated surrogate models

    KAUST Repository

    Yücel, Abdulkadir C.

    2011-08-01

    Stochastic methods have been used extensively to quantify effects due to uncertainty in system parameters (e.g. material, geometrical, and electrical constants) and/or excitation on observables pertinent to electromagnetic compatibility and interference (EMC/EMI) analysis (e.g. voltages across mission-critical circuit elements) [1]. In recent years, stochastic collocation (SC) methods, especially those leveraging generalized polynomial chaos (gPC) expansions, have received significant attention [2, 3]. SC-gPC methods probe surrogate models (i.e. compact polynomial input-output representations) to statistically characterize observables. They are nonintrusive, that is they use existing deterministic simulators, and often cost only a fraction of direct Monte-Carlo (MC) methods. Unfortunately, SC-gPC-generated surrogate models often lack accuracy (i) when the number of uncertain/random system variables is large and/or (ii) when the observables exhibit rapid variations. © 2011 IEEE.

  6. Uncertainty propagation through an aeroelastic wind turbine model using polynomial surrogates

    DEFF Research Database (Denmark)

    Murcia Leon, Juan Pablo; Réthoré, Pierre-Elouan Mikael; Dimitrov, Nikolay Krasimirov

    2017-01-01

    Polynomial surrogates are used to characterize the energy production and lifetime equivalent fatigue loads for different components of the DTU 10 MW reference wind turbine under realistic atmospheric conditions. The variability caused by different turbulent inflow fields are captured by creating......-alignment. The methodology presented extends the deterministic power and thrust coefficient curves to uncertainty models and adds new variables like damage equivalent fatigue loads in different components of the turbine. These surrogate models can then be implemented inside other work-flows such as: estimation...... of the uncertainty in annual energy production due to wind resource variability and/or robust wind power plant layout optimization. It can be concluded that it is possible to capture the global behavior of a modern wind turbine and its uncertainty under realistic inflow conditions using polynomial response surfaces...

  7. Neutron capture surrogate reaction on 75As in inverse kinematics using (d,pγ)

    Science.gov (United States)

    Peters, W. A.; Cizewski, J. A.; Hatarik, R.; O'Malley, P. D.; Jones, K. L.; Schmitt, K.; Moazen, B. H.; Chae, K. Y.; Pittman, S. T.; Kozub, R. L.; Vieira, D.; Jandel, M.; Wilhelmy, J. B.; Matei, C.; Escher, J.; Bardayan, D. W.; Pain, S. D.; Smith, M. S.

    2010-03-01

    The 75As(d,pγ) reaction in inverse kinematics as a surrogate for neutron capture was performed at Oak Ridge National Laboratory using a deuterated plastic target. The intensity of the 165 keV γ-ray from 76As in coincidence with ejected protons, from exciting 76As above the neutron separation energy populating a compound state, was measured. A tight geometry of four segmented germanium clover γ-ray detectors together with eight ORRUBA-type silicon-strip charged-particle detectors was used to optimize geometric acceptance. The preliminary analysis of the 75As experiment, and the efficacy and future plans of the (d,pγ) surrogate campaign in inverse kinematics, are discussed.

  8. Neutron Capture Surrogate Reaction on 75As in Inverse Kinematics Using (d,p(gamma))

    Energy Technology Data Exchange (ETDEWEB)

    Peters, W A; Cizewski, J A; Hatarik, R; O?Malley, P D; Jones, K L; Schmitt, K; Moazen, B H; Chae, K Y; Pittman, S T; Kozub, R L; Vieira, D; Jandel, M; Wilhelmy, J B; Matei, C; Escher, J; Bardayan, D W; Pain, S D; Smith, M S

    2009-11-09

    The {sup 75}As(d,p{gamma}) reaction in inverse kinematics as a surrogate for neutron capture was performed at Oak Ridge National Laboratory using a deuterated plastic target. The intensity of the 165 keV {gamma}-ray from {sup 76}As in coincidence with ejected protons, from exciting {sup 76}As above the neutron separation energy populating a compound state, was measured. A tight geometry of four segmented germanium clover {gamma}-ray detectors together with eight ORRUBA-type silicon-strip charged-particle detectors was used to optimize geometric acceptance. The preliminary analysis of the {sup 75}As experiment, and the efficacy and future plans of the (d,p{gamma}) surrogate campaign in inverse kinematics, are discussed.

  9. Neutron capture surrogate reaction on 75As in inverse kinematics using (d,p )

    Energy Technology Data Exchange (ETDEWEB)

    Peters, W. A. [Rutgers University; Cizewski, J. A. [Rutgers University; Hatarik, Robert [Rutgers University; O' Malley, Patrick [Rutgers University; Jones, K. L. [University of Tennessee; Schmitt, Kyle [University of Tennessee; Moazen, Brian [University of Tennessee; Chae, K. Y. [University of Tennessee; Pittman, S. T. [University of Tennessee, Knoxville (UTK); Kozub, R. L. [Tennessee Technological University; Vieira, D. J. [Los Alamos National Laboratory (LANL); Jandel, M. [Los Alamos National Laboratory (LANL); Wilhelmy, J. B. [Los Alamos National Laboratory (LANL); Matei, Catalin [Oak Ridge Associated Universities (ORAU); Escher, J. [Lawrence Livermore National Laboratory (LLNL); Bardayan, Daniel W [ORNL; Pain, Steven D [ORNL; Smith, Michael Scott [ORNL

    2010-01-01

    The 75As(d,p ) reaction in inverse kinematics as a surrogate for neutron capture was performed at Oak Ridge National Laboratory using a deuterated plastic target. The intensity of the 165 keV -ray from 76As in coincidence with ejected protons, from exciting 76As above the neutron separation energy populating a compound state, was measured. A tight geometry of four segmented germanium clover -ray detectors together with eight ORRUBA-type silicon-strip charged-particle detectors were used to optimize geometric acceptance. The preliminary analysis of the 75As experiment and the ecacy and future plans of the (d,p ) surrogate campaign in inverse kinematics are discussed.

  10. Surrogate modelling and optimization using shape-preserving response prediction: A review

    Science.gov (United States)

    Leifsson, Leifur; Koziel, Slawomir

    2016-03-01

    Computer simulation models are ubiquitous in modern engineering design. In many cases, they are the only way to evaluate a given design with sufficient fidelity. Unfortunately, an added computational expense is associated with higher fidelity models. Moreover, the systems being considered are often highly nonlinear and may feature a large number of designable parameters. Therefore, it may be impractical to solve the design problem with conventional optimization algorithms. A promising approach to alleviate these difficulties is surrogate-based optimization (SBO). Among proven SBO techniques, the methods utilizing surrogates constructed from corrected physics-based low-fidelity models are, in many cases, the most efficient. This article reviews a particular technique of this type, namely, shape-preserving response prediction (SPRP), which works on the level of the model responses to correct the underlying low-fidelity models. The formulation and limitations of SPRP are discussed. Applications to several engineering design problems are provided.

  11. Testing of organic waste surrogate materials in support of the Hanford organic tank program. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Turner, D.A. [Westinghouse Hanford Co., Richland, WA (United States); Miron, Y. [Bureau of Mines (United States)

    1994-01-01

    To address safety issues regarding effective waste management efforts of underground organic waste storage tanks at the Hanford Site, the Bureau of Mines conducted a series of tests, at the request of the Westinghouse Hanford company. In this battery of tests, the thermal and explosive characteristics of surrogate materials, chosen by Hanford, were determined. The surrogate materials were mixtures of inorganic and organic sodium salts, representing fuels and oxidants. The oxidants were sodium nitrate and sodium nitrite. The fuels were sodium salts of oxalate, citrate and ethylenediamine tetraacetic acid (EDTA). Polyethylene powder was also used as a fuel with the oxidant(s). Sodium aluminate was used as a diluent. In addition, a sample of FeCN, supplied by Hanford was also investigated.

  12. Multiobjective Optimization Design of Double-Row Blades Hydraulic Retarder with Surrogate Model

    Directory of Open Access Journals (Sweden)

    Liu Chunbao

    2015-02-01

    Full Text Available For the design of double-row blades hydraulic retarder involves too many parameters, the solution process of the optimal parameter combination is characterized by the large calculation load, the long calculation time, and the high cost. In this paper, we proposed a multiobjective optimization method to obtain the optimal balanced solution between the braking torque and volume of double-row blades hydraulic retarder. Moreover, we established the surrogate model for objective function with radial basis function (RBF, thus avoiding the time-consuming three-dimensional modeling and fluid simulation. Then, nondominated sorting genetic algorithm-II (NSGA-II was adopted to obtain the optimal combination solution of design variables. Moreover, the comparison results of computational fluid dynamics (CFD values of the optimal combination parameters and original design parameters indicated that the multiobjective optimization method based on surrogate model was applicable for the design of double-row blades hydraulic retarder.

  13. Determination of neutron-induced fission cross-sections of unstable nuclei via surrogate reaction method

    Indian Academy of Sciences (India)

    B K Nayak

    2014-11-01

    Heavy ion reaction studies around Coulomb barrier energies have been generally used to investigate the effect of the structure of projectile/target on reaction dynamics. Other than providing an understanding of basic physics of the reaction dynamics, some of these reactions have been used as tools to serve as surrogates of neutron-induced compound nuclear fission cross-sections involving unstable targets. In this paper, we report some of the recent results on the determination of neutron-induced fission cross-sections of unstable actinides present in Th–U and U–Pu fuel cycles by surrogate reaction method by employing transfer-induced fission studies with 6,7Li beams.

  14. Fuel Surrogate Physical Property Effects on Direct Injection Spray and Ignition Behavior

    Science.gov (United States)

    2015-09-01

    UNCLASSIFIED 1 Introduction Typical hydrocarbon fuels used in internal combustion engines , such as gasoline, diesel , or jet fuel, are composed of hundreds...optimization, which determines the surrogate composition that minimizes the deviation from the target properties. For modern diesel engines , which employ...of biodiesel and diesel fuel. Pei et al. [20] conducted a sensitivity analysis with a diesel engine simulation to assess the relative effects of

  15. SVAw - a web-based application tool for automated surrogate variable analysis of gene expression studies.

    Science.gov (United States)

    Pirooznia, Mehdi; Seifuddin, Fayaz; Goes, Fernando S; Leek, Jeffrey T; Zandi, Peter P

    2013-03-11

    Surrogate variable analysis (SVA) is a powerful method to identify, estimate, and utilize the components of gene expression heterogeneity due to unknown and/or unmeasured technical, genetic, environmental, or demographic factors. These sources of heterogeneity are common in gene expression studies, and failing to incorporate them into the analysis can obscure results. Using SVA increases the biological accuracy and reproducibility of gene expression studies by identifying these sources of heterogeneity and correctly accounting for them in the analysis. Here we have developed a web application called SVAw (Surrogate variable analysis Web app) that provides a user friendly interface for SVA analyses of genome-wide expression studies. The software has been developed based on open source bioconductor SVA package. In our software, we have extended the SVA program functionality in three aspects: (i) the SVAw performs a fully automated and user friendly analysis workflow; (ii) It calculates probe/gene Statistics for both pre and post SVA analysis and provides a table of results for the regression of gene expression on the primary variable of interest before and after correcting for surrogate variables; and (iii) it generates a comprehensive report file, including graphical comparison of the outcome for the user. SVAw is a web server freely accessible solution for the surrogate variant analysis of high-throughput datasets and facilitates removing all unwanted and unknown sources of variation. It is freely available for use at http://psychiatry.igm.jhmi.edu/sva. The executable packages for both web and standalone application and the instruction for installation can be downloaded from our web site.

  16. Sparse Polynomial Chaos Surrogate for ACME Land Model via Iterative Bayesian Compressive Sensing

    Science.gov (United States)

    Sargsyan, K.; Ricciuto, D. M.; Safta, C.; Debusschere, B.; Najm, H. N.; Thornton, P. E.

    2015-12-01

    For computationally expensive climate models, Monte-Carlo approaches of exploring the input parameter space are often prohibitive due to slow convergence with respect to ensemble size. To alleviate this, we build inexpensive surrogates using uncertainty quantification (UQ) methods employing Polynomial Chaos (PC) expansions that approximate the input-output relationships using as few model evaluations as possible. However, when many uncertain input parameters are present, such UQ studies suffer from the curse of dimensionality. In particular, for 50-100 input parameters non-adaptive PC representations have infeasible numbers of basis terms. To this end, we develop and employ Weighted Iterative Bayesian Compressive Sensing to learn the most important input parameter relationships for efficient, sparse PC surrogate construction with posterior uncertainty quantified due to insufficient data. Besides drastic dimensionality reduction, the uncertain surrogate can efficiently replace the model in computationally intensive studies such as forward uncertainty propagation and variance-based sensitivity analysis, as well as design optimization and parameter estimation using observational data. We applied the surrogate construction and variance-based uncertainty decomposition to Accelerated Climate Model for Energy (ACME) Land Model for several output QoIs at nearly 100 FLUXNET sites covering multiple plant functional types and climates, varying 65 input parameters over broad ranges of possible values. This work is supported by the U.S. Department of Energy, Office of Science, Biological and Environmental Research, Accelerated Climate Modeling for Energy (ACME) project. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  17. An efficient surrogate-based simulation-optimization method for calibrating a regional MODFLOW model

    Science.gov (United States)

    Chen, Mingjie; Izady, Azizallah; Abdalla, Osman A.

    2017-01-01

    Simulation-optimization method entails a large number of model simulations, which is computationally intensive or even prohibitive if the model simulation is extremely time-consuming. Statistical models have been examined as a surrogate of the high-fidelity physical model during simulation-optimization process to tackle this problem. Among them, Multivariate Adaptive Regression Splines (MARS), a non-parametric adaptive regression method, is superior in overcoming problems of high-dimensions and discontinuities of the data. Furthermore, the stability and accuracy of MARS model can be improved by bootstrap aggregating methods, namely, bagging. In this paper, Bagging MARS (BMARS) method is integrated to a surrogate-based simulation-optimization framework to calibrate a three-dimensional MODFLOW model, which is developed to simulate the groundwater flow in an arid hardrock-alluvium region in northwestern Oman. The physical MODFLOW model is surrogated by the statistical model developed using BMARS algorithm. The surrogate model, which is fitted and validated using training dataset generated by the physical model, can approximate solutions rapidly. An efficient Sobol' method is employed to calculate global sensitivities of head outputs to input parameters, which are used to analyze their importance for the model outputs spatiotemporally. Only sensitive parameters are included in the calibration process to further improve the computational efficiency. Normalized root mean square error (NRMSE) between measured and simulated heads at observation wells is used as the objective function to be minimized during optimization. The reasonable history match between the simulated and observed heads demonstrated feasibility of this high-efficient calibration framework.

  18. The temporal and spatial characteristics of surrogate tropical cyclones from a multi-millenial simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, B.G.; Watterson, I.G. [CSIRO Marine and Atmospheric Research, PO Box 1, Aspendale (Australia)

    2010-04-15

    Output from a simulation with the CSIRO Mark 2 climatic model has been used to investigate the secular variability of tropical cyclone formation over the globe using Gray's Seasonal Genesis Parameter. This simulation differs from previous surrogate studies in using a coupled atmospheric-oceanic model, instead of specified sea surface temperatures, as well as being of multi-millenial duration, compared with decadal length simulations used elsewhere. Mean climatological values for each season for a 5,000-year period indicate that the model replicated the broad patterns of spatial and temporal variability. Results are presented in some detail for three regions, the southwest and northwest Pacific Oceans and the low latitude North Atlantic Ocean. A marked range of temporal variabilities of surrogate tropical cyclone numbers was obtained in the simulation, possibly indicating that the present, observed increase in these numbers may not be outside that attributable to natural variability. The component terms of the Seasonal Genesis Parameter permit the contribution of individual climatic terms to the generation of tropical cyclones to be identified. This approach highlighted the important role of relative vorticity and relative humidity, in addition to the governing influence of vertical wind shear. The remote influence of ENSO, versus that of local sea surface temperature anomalies, on surrogate tropical cyclone numbers was examined and revealed different outcomes depending on the region under consideration. The global total of surrogate tropical cyclone numbers exhibited noticeable interannual variability. The simulation reproduced most of the observed correlations between tropical cyclones and relevant climatic variables, but many of the correlations were not stable within the 5,000-year time series used. This suggests that observed correlations based on, typically, 100-years or less of data may not be representative of possible future outcomes. With minor

  19. The temporal and spatial characteristics of surrogate tropical cyclones from a multi-millenial simulation

    Science.gov (United States)

    Hunt, B. G.; Watterson, I. G.

    2010-04-01

    Output from a simulation with the CSIRO Mark 2 climatic model has been used to investigate the secular variability of tropical cyclone formation over the globe using Gray’s Seasonal Genesis Parameter. This simulation differs from previous surrogate studies in using a coupled atmospheric-oceanic model, instead of specified sea surface temperatures, as well as being of multi-millenial duration, compared with decadal length simulations used elsewhere. Mean climatological values for each season for a 5,000-year period indicate that the model replicated the broad patterns of spatial and temporal variability. Results are presented in some detail for three regions, the southwest and northwest Pacific Oceans and the low latitude North Atlantic Ocean. A marked range of temporal variabilities of surrogate tropical cyclone numbers was obtained in the simulation, possibly indicating that the present, observed increase in these numbers may not be outside that attributable to natural variability. The component terms of the Seasonal Genesis Parameter permit the contribution of individual climatic terms to the generation of tropical cyclones to be identified. This approach highlighted the important role of relative vorticity and relative humidity, in addition to the governing influence of vertical wind shear. The remote influence of ENSO, versus that of local sea surface temperature anomalies, on surrogate tropical cyclone numbers was examined and revealed different outcomes depending on the region under consideration. The global total of surrogate tropical cyclone numbers exhibited noticeable interannual variability. The simulation reproduced most of the observed correlations between tropical cyclones and relevant climatic variables, but many of the correlations were not stable within the 5,000-year time series used. This suggests that observed correlations based on, typically, 100-years or less of data may not be representative of possible future outcomes. With minor

  20. Neutron-induced capture cross sections of short-lived actinides with the surrogate reaction method

    Directory of Open Access Journals (Sweden)

    Gunsing F.

    2010-03-01

    Full Text Available Determination of neutron-capture cross sections of short-lived nuclei is opening the way to understand and clarify the properties of many nuclei of interest for nuclear structure physics, nuclear astrophysics and particularly for transmutation of nuclear wastes. The surrogate approach is well-recognized as a potentially very useful method to extract neutron cross sections for low-energy compound-nuclear reactions and to overcome the difficulties related to the target radioactivity. In this work we will assess where we stand on these neutron-capture cross section measurements and how we can achieve the short-lived Minor Actinides nuclei involved in the nuclear fuel cycle. The CENBG collaboration applied the surrogate method to determine the neutron-capture cross section of 233Pa (T1/2 = 27 d. The 233Pa (n,γ cross section is then deduced from the measured gamma decay probability of 234Pa compound nucleus formed via the surrogate 232Th(3He,p reaction channel. The obtained cross section data, covering the neutron energy range 0.1 to 1 MeV, have been compared with the predictions of the Hauser-Feshbach statistical model. The importance of establishing benchmarks is stressed for the minor actinides region. However, the lack of desired targets led us to propose recently the 174Yb (3He,pγ reaction as a surrogate reaction for the (n,γ predetermined benchmark cross section of 175Lu. An overview of the experimental setup combining gamma ray detectors such as Ge and C6D6 in coincidence with light charged particles ΔE-E Telescopes will be presented and preliminary results will be discussed.

  1. Preignition Chemistry of Xylenes and Their Effect on JP-8 Surrogates

    Science.gov (United States)

    2008-06-01

    The Effects of DTBP on the Oxidation of SI Primary Reference Fuels – A Study in an HCCI Engine and in a Pressurized Flow Reactor,” Ph.D. Thesis...blends with paraffins, and in JP-8 surrogates in a pressurized flow reactor, with complimentary experiments conducted in a single cylinder research engine ...Preignition Oxidation Chemistry of Xylene.” A tribute book for Professor Eliseo Ranzi, Italian Chemical Engineering Society, June 2008. 0.00Number of

  2. The Oxidation of a Gasoline Surrogate in the Negative Temperature Coefficient Region

    Science.gov (United States)

    2009-02-12

    used to model homo- geneous charge compression ignition ( HCCI ) engines with reason- able success [25]. The initial conditions for the surrogate mixture...Owens b a Department of Mechanical Engineering and Mechanics, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104-2875, USA b Department...critical for solving the problem of knock in spark igni- tion engines and for the development of Low Temperature Com- bustion engine technologies such as

  3. Percent recovery of low influent concentrations of microorganism surrogates in small sand columns

    Science.gov (United States)

    Stevenson, M. E.; Blaschke, A. P.

    2012-04-01

    In order to develop a dependable method to calculate the setback distance of a drinking water well from a potential point of microbiological contamination, surrogates are used to perform field tests to avoid using pathogenic micro-organisms. One such surrogate used to model the potential travel time of microbial contamination is synthetic microspheres. The goal of this study is to examine the effect of differing influent colloid concentrations on the percent recovery of microbial surrogates after passing through a soil column. Similar studies have been done to investigate blocking of ideal attachment sites using concentrations between 106 and 1010 particles ml-1. These high concentrations were necessary due to the detection limit of the measuring technique used; however, our measuring technique allows us to test input concentrations ranging from 101 to 106 particles ml-1. These low concentrations are more similar to the concentrations of pathogenic microorganisms present in nature. We have tested the enumeration of 0.5 μm microspheres using a solid-phase cytometer and evaluated their transport in small sand columns. Fluorescent microspheres were purchased for this study with carboxylated surfaces. The soil columns consist of Plexiglas tubes, 30 cm long and 7 cm in diameter, both filled with the same coarse sand. Bromide was used as a conservative tracer, to estimate pore-water velocity and dispersivity, and bromide concentrations were analysed using ion chromatography and bromide probes. Numerical modelling was done using CXTFIT and HYDRUS-1D software programs. The 0.5 μm beads were enumerated in different environmental waters using solid-phase cytometry and compared to counts in sterile water in order to confirm the accuracy of the method. The solid-phase cytometer was able to differentiate the 0.5 μm beads from naturally present autofluorescent particles and bacteria, and therefore, is an appropriate method to enumerate this surrogate.

  4. Generation of Comprehensive Surrogate Kinetic Models and Validation Databases for Simulating Large Molecular Weight Hydrocarbon Fuels

    Science.gov (United States)

    2012-10-25

    composed of highly isomerized paraffinic kerosene (denoted IPK). Comparisons of a 2nd generation surrogate formulated to match all four of the above...and di methyl alkanes was emulated using mixtures of n-dodecane and iso-octane that replicated its combustion property targets, demonstrating that... methyl heptane was shown to replicate the global combustion properties of the weakly branched isomer, further supporting that distinct functional

  5. Rail-to-rail differential input amplification stage with main and surrogate differential pairs

    Energy Technology Data Exchange (ETDEWEB)

    Britton, Jr., Charles Lanier; Smith, Stephen Fulton

    2007-03-06

    An operational amplifier input stage provides a symmetrical rail-to-rail input common-mode voltage without turning off either pair of complementary differential input transistors. Secondary, or surrogate, transistor pairs assume the function of the complementary differential transistors. The circuit also maintains essentially constant transconductance, constant slew rate, and constant signal-path supply current as it provides rail-to-rail operation.

  6. An Efficient Variable Screening Method for Effective Surrogate Models for Reliability-Based Design Optimization

    Science.gov (United States)

    2014-04-01

    reliability-based design optimization ( RBDO ) process, surrogate models are frequently used to reduce the number of simulations because analysis of a...the RBDO problem and thus mitigate the curse of dimensionality. Therefore, it is desirable to develop an efficient and effective variable...screening method for reduction of the dimension of the RBDO problem. In this paper, requirements of the variable screening method for deterministic design

  7. Effectiveness of sanitizing products on controlling selected pathogen surrogates on retail deli slicers.

    Science.gov (United States)

    Yeater, Michael C; Kirsch, Katie R; Taylor, T Matthew; Mitchell, Jeff; Osburn, Wesley N

    2015-04-01

    The objectives of this study were (i) to assess the efficacy of quaternary ammonium chloride-based wet foam (WF) and dry foam (DF) sanitizer systems (600 ppm) for reducing Listeria innocua (a nonpathogenic surrogate of Listeria monocytogenes) or a 100.0 μg/ml rifampin-resistant Salmonella Typhimurium LT2 (a nonpathogenic surrogate of Salmonella enterica serovar Typhimurium) on niche and transfer point areas of an unwashed retail deli slicer as compared with traditional chlorine (Cl(-)) treatment (200 ppm) and (ii) to compare sanitizer surface contact times (10 and 15 min) for pathogen surrogate control. Turkey frankfurter slurries inoculated with L. innocua or Salmonella Typhimurium were used to inoculate seven high-risk sites on a commercial slicer. After 30 min of bacterial attachment, slicers were dry wiped to remove excess food matter, followed by a randomly assigned sanitizer treatment. Surviving pathogen surrogate cells were enumerated on modified Oxford's agar not containing antimicrobic supplement (L. innocua) or on tryptic soy agar supplemented with 100 μg/ml rifampin (Salmonella Typhimurium LT2). Replicate-specific L. innocua and Salmonella Typhimurium reductions were calculated as log CFU per square centimeter of control minus log CFU per square centimeter of enumerated survivors for each site. For both organisms, all sanitizer treatments differed from each other, with Cl(-) producing the least reduction and WF the greatest reduction. A significant (P < 0.05) site-by-treatment interaction was observed. The results of the study indicate that quaternary ammonium chloride sanitizers (600 ppm) applied by both WF and DF were more effective at reducing L. innocua and Salmonella Typhimurium than a traditional Cl sanitizer (200 ppm) on unwashed slicer surfaces.

  8. Parameter identification and calibration of the Xin'anjiang model using the surrogate modeling approach

    Science.gov (United States)

    Ye, Yan; Song, Xiaomeng; Zhang, Jianyun; Kong, Fanzhe; Ma, Guangwen

    2014-06-01

    Practical experience has demonstrated that single objective functions, no matter how carefully chosen, prove to be inadequate in providing proper measurements for all of the characteristics of the observed data. One strategy to circumvent this problem is to define multiple fitting criteria that measure different aspects of system behavior, and to use multi-criteria optimization to identify non-dominated optimal solutions. Unfortunately, these analyses require running original simulation models thousands of times. As such, they demand prohibitively large computational budgets. As a result, surrogate models have been used in combination with a variety of multi-objective optimization algorithms to approximate the true Pareto-front within limited evaluations for the original model. In this study, multi-objective optimization based on surrogate modeling (multivariate adaptive regression splines, MARS) for a conceptual rainfall-runoff model (Xin'anjiang model, XAJ) was proposed. Taking the Yanduhe basin of Three Gorges in the upper stream of the Yangtze River in China as a case study, three evaluation criteria were selected to quantify the goodness-of-fit of observations against calculated values from the simulation model. The three criteria chosen were the Nash-Sutcliffe efficiency coefficient, the relative error of peak flow, and runoff volume (REPF and RERV). The efficacy of this method is demonstrated on the calibration of the XAJ model. Compared to the single objective optimization results, it was indicated that the multi-objective optimization method can infer the most probable parameter set. The results also demonstrate that the use of surrogate-modeling enables optimization that is much more efficient; and the total computational cost is reduced by about 92.5%, compared to optimization without using surrogate modeling. The results obtained with the proposed method support the feasibility of applying parameter optimization to computationally intensive simulation

  9. Real-time surrogate analysis for potential oil and gas contamination of drinking water resources

    Science.gov (United States)

    Son, Ji-Hee; Carlson, Kenneth H.

    2015-09-01

    Public concerns related to the fast-growing shale oil and gas industry have increased during recent years. The major concern regarding shale gas production is the potential of fracturing fluids being injected into the well or produced fluids flowing out of the well to contaminate drinking water resources such as surface water and groundwater. Fracturing fluids contain high total dissolved solids (TDS); thus, changes in TDS concentrations in groundwater might indicate influences of fracturing fluids. An increase of methane concentrations in groundwater could also potentially be due to hydraulic fracturing activities. To understand the possible contamination of groundwater by fracturing activities, real-time groundwater monitoring is being implemented in the Denver-Julesburg basin of northeast Colorado. A strategy of monitoring of surrogate parameters was chosen instead of measuring potential contaminants directly, an approach that is not cost effective or operationally practical. Contaminant surrogates of TDS and dissolved methane were proposed in this study, and were tested for correlation and data distribution with laboratory experiments. Correlations between TDS and electrical conductivity (EC), and between methane contamination and oxidation-reduction potential (ORP) were strong at low concentrations of contaminants (1 mg/L TDS and 0.3 mg/L CH4). Dissolved oxygen (DO) was only an effective surrogate at higher methane concentrations (≥2.5 mg/L). The results indicated that EC and ORP are effective surrogates for detecting concentration changes of TDS and methane, respectively, and that a strategy of monitoring for easy to measure parameters can be effective detecting real-time, anomalous behavior relative to a predetermined baseline.

  10. Molecular Beam Studies of Volatile Liquids and Fuel Surrogates Using Liquid Microjets

    Science.gov (United States)

    2014-12-18

    Molecular Beam Studies of Volatile Liquids and Fuel Surrogates Using Liquid Microjets Gilbert Nathanson, Department of Chemistry University of...alter the dynamics of evaporation from the commercial jet fuel Jet A. These results are outlined below. Exploring Fuels in Vacuum using Liquid ...hydrocarbon liquids inside a vacuum chamber. These jets, narrower than a human hair, are typically 10 – 40 µm in diameter. Their small surface area and

  11. Hospitalization for early bonding of the genetic mother after a surrogate pregnancy: report of two cases.

    Science.gov (United States)

    Sharan, H; Yahav, J; Peleg, D; Ben-Rafael, Z; Merlob, P

    2001-12-01

    In surrogate pregnancies the genetic parents have little opportunity for early bonding to their infant, either prenatally (in utero) or in the immediate postnatal period. The purpose of this article is to describe a new method for encouraging early parent-infant bonding after surrogate pregnancy by hospitalizing the genetic mother in the maternity ward immediately after the delivery. Two genetic mothers were hospitalized in the maternity ward (rooming-in system) at the Rabin Medical Center in Israel immediately after delivery of their infants by surrogate arrangement. The first birth was a singleton pregnancy with vaginal delivery and the second, a twin pregnancy with delivery by cesarean section. The genetic parents were counseled by a social worker from the adoption agency, starting 3 months before the estimated date of delivery. The parents were referred to the hospital social worker before the delivery. To assess attachment, we observed the parents' behavior toward their children during two daily 15-minute periods of free, unstructured interaction. The parents showed good primary caregiving functions and established affective verbal and physical contact with the infants. They began to recognize the infants' needs and temperament, and exhibited an aura of self-confidence during their interactions. All expressed satisfaction with the method at discharge and reported on reduction of their fears about returning home with the infants. We believe that early hospitalization of the genetic mother in a surrogate delivery may be desirable to establish good and safe early mother-infant bonding, and that it should be considered for adoption as regular hospital policy. Further randomized studies with larger samples over the long term are warranted.

  12. Domino Synthesis of Thiochromenes through Cu-Catalyzed Incorporation of Sulfur Using Xanthate Surrogate.

    Science.gov (United States)

    Muthupandi, Pandi; Sundaravelu, Nallappan; Sekar, Govindasamy

    2017-02-17

    An efficient domino reaction has been developed for the synthesis of thiochromenes through Cu-catalyzed in situ incorporation of sulfur. This domino method avoids the use of less accessible and unpleasant arenethiols as starting materials, instead utilizes very stable aryl halides along with potassium ethyl xanthate as an odorless sulfur surrogate. The domino methodology proceeds through C(aryl)-S coupling, thioester cleavage, sulfa-Michael addition, aldol reaction, and elimination reaction sequences to provide thiochromenes in good yields.

  13. A computer-based education intervention to enhance surrogates' informed consent for genomics research.

    Science.gov (United States)

    Shelton, Ann K; Freeman, Bradley D; Fish, Anne F; Bachman, Jean A; Richardson, Lloyd I

    2015-03-01

    Many research studies conducted today in critical care have a genomics component. Patients' surrogates asked to authorize participation in genomics research for a loved one in the intensive care unit may not be prepared to make informed decisions about a patient's participation in the research. To examine the effectiveness of a new, computer-based education module on surrogates' understanding of the process of informed consent for genomics research. A pilot study was conducted with visitors in the waiting rooms of 2 intensive care units in a Midwestern tertiary care medical center. Visitors were randomly assigned to the experimental (education module plus a sample genomics consent form; n = 65) or the control (sample genomics consent form only; n = 69) group. Participants later completed a test on informed genomics consent. Understanding the process of informed consent was greater (P = .001) in the experimental group than in the control group. Specifically, compared with the control group, the experimental group had a greater understanding of 8 of 13 elements of informed consent: intended benefits of research (P = .02), definition of surrogate consenter (P= .001), withdrawal from the study (P = .001), explanation of risk (P = .002), purpose of the institutional review board (P = .001), definition of substituted judgment (P = .03), compensation for harm (P = .001), and alternative treatments (P = .004). Computer-based education modules may be an important addition to conventional approaches for obtaining informed consent in the intensive care unit. Preparing patients' family members who may consider serving as surrogate consenters is critical to facilitating genomics research in critical care. ©2015 American Association of Critical-Care Nurses.

  14. Rail-to-rail differential input amplification stage with main and surrogate differential pairs

    Science.gov (United States)

    Britton, Jr., Charles Lanier; Smith, Stephen Fulton

    2007-03-06

    An operational amplifier input stage provides a symmetrical rail-to-rail input common-mode voltage without turning off either pair of complementary differential input transistors. Secondary, or surrogate, transistor pairs assume the function of the complementary differential transistors. The circuit also maintains essentially constant transconductance, constant slew rate, and constant signal-path supply current as it provides rail-to-rail operation.

  15. Dynamic impact indentation of hydrated biological tissues and tissue surrogate gels

    Science.gov (United States)

    Ilke Kalcioglu, Z.; Qu, Meng; Strawhecker, Kenneth E.; Shazly, Tarek; Edelman, Elazer; VanLandingham, Mark R.; Smith, James F.; Van Vliet, Krystyn J.

    2011-03-01

    For both materials engineering research and applied biomedicine, a growing need exists to quantify mechanical behaviour of tissues under defined hydration and loading conditions. In particular, characterisation under dynamic contact-loading conditions can enable quantitative predictions of deformation due to high rate 'impact' events typical of industrial accidents and ballistic insults. The impact indentation responses were examined of both hydrated tissues and candidate tissue surrogate materials. The goals of this work were to determine the mechanical response of fully hydrated soft tissues under defined dynamic loading conditions, and to identify design principles by which synthetic, air-stable polymers could mimic those responses. Soft tissues from two organs (liver and heart), a commercially available tissue surrogate gel (Perma-Gel™) and three styrenic block copolymer gels were investigated. Impact indentation enabled quantification of resistance to penetration and energy dissipative constants under the rates and energy densities of interest for tissue surrogate applications. These analyses indicated that the energy dissipation capacity under dynamic impact increased with increasing diblock concentration in the styrenic gels. Under the impact rates employed (2 mm/s to 20 mm/s, corresponding to approximate strain energy densities from 0.4 kJ/m3 to 20 kJ/m3), the energy dissipation capacities of fully hydrated soft tissues were ultimately well matched by a 50/50 triblock/diblock composition that is stable in ambient environments. More generally, the methodologies detailed here facilitate further optimisation of impact energy dissipation capacity of polymer-based tissue surrogate materials, either in air or in fluids.

  16. A causal framework for surrogate endpoints with semi-competing risks data.

    Science.gov (United States)

    Ghosh, Debashis

    2012-10-01

    In this note, we address the problem of surrogacy using a causal modelling framework that differs substantially from the potential outcomes model that pervades the biostatistical literature. The framework comes from econometrics and conceptualizes direct effects of the surrogate endpoint on the true endpoint. While this framework can incorporate the so-called semi-competing risks data structure, we also derive a fundamental non-identifiability result. Relationships to existing causal modelling frameworks are also discussed.

  17. Cellular therapies based on stem cells and their insulin-producing surrogates: a 2015 reality check.

    Science.gov (United States)

    Giannoukakis, Nick; Trucco, Massimo

    2015-05-01

    Stem cell technology has recently gained a substantial amount of interest as one method to create a potentially limitless supply of transplantable insulin-producing cells to treat, and possibly cure diabetes mellitus. In this review, we summarize the state-of-the art of stem cell technology and list the potential sources of stem cells that have been shown to be useful as insulin-expressing surrogates. We also discuss the milestones that have been reached and those that remain to be addressed to generate bona fide beta cell-similar, insulin-producing surrogates. The caveats, limitations, and realistic expectations are also considered for current and future technology. In spite of the tremendous technical advances realized in the past decade, especially in the field of reprogramming adult somatic cells to become stem cells, the state-of-the art still relies on lengthy and cumbersome in vitro culture methods that yield cell populations that are not particularly glucose-responsive when transplanted into diabetic hosts. Despite the current impediments toward clinical translation, including the potential for immune rejection, the availability of technology to generate patient-specific reprogrammable stem cells has, and will be critical for, important insights into the genetics, epigenetics, biology, and physiology of insulin-producing cells in normal and pathologic states. This knowledge could accelerate the time to reach the desired breakthrough for safe and efficacious beta cell surrogates.

  18. Concentration and retention of Toxoplasma gondii surrogates from seawater by red abalone (Haliotis rufescens)

    Science.gov (United States)

    Schott, Kristen C; Krusor, Colin; Tinker, M. Tim; Moore, James G.; Conrad, Patricia A.; Shapiro, Karen

    2016-01-01

    Small marine snails and abalone have been identified as high- and low-risk prey items, respectively, for exposure of threatened southern sea otters to Toxoplasma gondii, a zoonotic parasite that can cause fatal encephalitis in animals and humans. While recent work has characterized snails as paratenic hosts for T. gondii, the ability of abalone to vector the parasite has not been evaluated. To further elucidate why abalone predation may be protective against T. gondii exposure, this study aimed to determine whether: (1) abalone are physiologically capable of acquiring T. gondii; and (2) abalone and snails differ in their ability to concentrate and retain the parasite. Abalone were exposed to T. gondii surrogate microspheres for 24 h, and fecal samples were examined for 2 weeks following exposure. Concentration of surrogates was 2–3 orders of magnitude greater in abalone feces than in the spiked seawater, and excretion of surrogates continued for 14 days post-exposure. These results indicate that, physiologically, abalone and snails can equally vector T. gondii as paratenic hosts. Reduced risk of T. gondii infection in abalone-specializing otters may therefore result from abalone's high nutritional value, which implies otters must consume fewer animals to meet their caloric needs.

  19. Surrogate models for identifying robust, high yield regions of parameter space for ICF implosion simulations

    Science.gov (United States)

    Humbird, Kelli; Peterson, J. Luc; Brandon, Scott; Field, John; Nora, Ryan; Spears, Brian

    2016-10-01

    Next-generation supercomputer architecture and in-transit data analysis have been used to create a large collection of 2-D ICF capsule implosion simulations. The database includes metrics for approximately 60,000 implosions, with x-ray images and detailed physics parameters available for over 20,000 simulations. To map and explore this large database, surrogate models for numerous quantities of interest are built using supervised machine learning algorithms. Response surfaces constructed using the predictive capabilities of the surrogates allow for continuous exploration of parameter space without requiring additional simulations. High performing regions of the input space are identified to guide the design of future experiments. In particular, a model for the yield built using a random forest regression algorithm has a cross validation score of 94.3% and is consistently conservative for high yield predictions. The model is used to search for robust volumes of parameter space where high yields are expected, even given variations in other input parameters. Surrogates for additional quantities of interest relevant to ignition are used to further characterize the high yield regions. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, Lawrence Livermore National Security, LLC. LLNL-ABS-697277.

  20. Stability of and attachment to lettuce by a culturable porcine sapovirus surrogate for human caliciviruses.

    Science.gov (United States)

    Wang, Qiuhong; Zhang, Zhenwen; Saif, Linda J

    2012-06-01

    Human noroviruses (HuNoVs) are the leading cause of food-borne illness, accounting for 58% of U.S. cases. Because HuNoVs are unculturable, surrogates are needed to investigate transmission routes and evaluate disinfection methods. However, the current surrogates, feline calicivirus (FCV) and murine NoV (MNV), are less tolerant than HuNoVs to acid and chlorine, respectively. Porcine sapovirus (SaV) is the only culturable enteropathogenic calicivirus. In this study, the resistance of SaV to physicochemical treatments was compared to that of HuNoVs (by reverse transcription-PCR), FCV, and MNV (by infectivity assays). Sapovirus and HuNoV (viral RNA) showed similar resistances to heat (56°C) and to different concentrations of chlorine. However, SaV was more resistant than HuNoVs to ethanol treatment (60% and 70%). Like HuNoVs, SaV was stable at pH 3.0 to 8.0, with a Sapovirus attached to lettuce leaves significantly at its capsid isoelectric point (pH 5.0), and the attached viral particles remained infectious on lettuce after 1 week of storage at 4°C. The culturable SaV is a good surrogate for studying HuNoV contamination and transmission in leafy greens and potential disinfectants.

  1. Laminar Flame Speeds of Gasoline Surrogates Measured with the Flat Flame Method

    KAUST Repository

    Liao, Y.-H.

    2016-01-27

    © 2016 American Chemical Society. The adiabatic, laminar flame speeds of gasoline surrogates at atmospheric pressure over a range of equivalence ratios of = 0.8-1.3 and unburned gas temperatures of 298-400 K are measured with the flat flame method, which produces a one-dimensional flat flame free of stretch. Surrogates used in the current work are the primary reference fuels (PRFs, mixtures of n-heptane and isooctane), the toluene reference fuels (TRFs, mixtures of toluene and PRFs), and the ethanol reference fuels (ERFs, mixtures of ethanol and PRFs). In general, there is good agreement between the present work and the literature data for single-component fuel and PRF mixtures. Surrogates of TRF mixtures are found to exhibit comparable flame speeds to a real gasoline, while there is discrepancy observed between isooctane and gasoline. Moreover, the laminar flame speeds of TRF mixtures with similar fractions of n-heptane are found to be insensitive to the quantity of toluene in the mixture. Mixtures of ERFs exhibit comparable flame speeds to those of TRFs with similar mole fractions of n-heptane and isooctane.

  2. Streamflow dynamics at the Puget Sound, Washington: application of a surrogate data method

    Directory of Open Access Journals (Sweden)

    N. She

    2005-01-01

    Full Text Available Recent progress in nonlinear dynamic theory has inspired hydrologists to apply innovative nonlinear time series techniques to the analysis of streamflow data. However, regardless of the method employed to analyze streamflow data, the first step should be the identification of underlying dynamics using one or more methods that could distinguish between linear and nonlinear, deterministic and stochastic processes from data itself. In recent years a statistically rigorous framework to test whether or not the examined time series is generated by a Gaussian (linear process undergoing a possibly nonlinear static transform is provided by the method of surrogate data. The surrogate data, generated to represent the null hypothesis, are compared to the original data under a nonlinear discriminating statistic in order to reject or approve the null hypothesis. In recognition of this tendency, the method of 'surrogate data' is applied herein to determine the underlying linear stochastic or nonlinear deterministic nature of daily streamflow data observed from the central basin of Puget Sound, and as applicable, distinguish between the static or dynamic nonlinearity of the data in question.

  3. UQ -- Fast Surrogates Key to New Methodologies in an Operational and Research Volcanic Hazard Forecasting System

    Science.gov (United States)

    Hughes, C. G.; Stefanescu, R. E. R.; Patra, A. K.; Bursik, M. I.; Madankan, R.; Pouget, S.; Jones, M.; Singla, P.; Singh, T.; Pitman, E. B.; Morton, D.; Webley, P.

    2014-12-01

    As the decision to construct a hazard map is frequently precipitated by the sudden initiation of activity at a volcano that was previously considered dormant, timely completion of the map is imperative. This prohibits the calculation of probabilities through direct sampling of a numerical ash-transport and dispersion model. In developing a probabilistic forecast for ash cloud locations following an explosive volcanic eruption, we construct a number of possible meta-models (a model of the simulator) to act as fast surrogates for the time-expensive model. We will illustrate the new fast surrogates based on both polynomial chaos and multilevel sparse representations that have allowed us to conduct the Uncertainty Quantification (UQ) in a timely fashion. These surrogates allow orders of magnitude improvement in cost associated with UQ, and are likely to have a major impact in many related domains.This work will be part of an operational and research volcanic forecasting system (see the Webley et al companion presentation) moving towards using ensembles of eruption source parameters and Numerical Weather Predictions (NWPs), rather than single deterministic forecasts, to drive the ash cloud forecasting systems. This involves using an Ensemble Prediction System (EPS) as input to an ash transport and dispersion model, such as PUFF, to produce ash cloud predictions, which will be supported by a Decision Support System. Simulation ensembles with different input volcanic source parameters are intelligently chosen to predict the average and higher-order moments of the output correctly.

  4. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F S; Moody, K J; Norman, E B; Phair, L; Fallon, P; Clark, R M; Deleplanque, M A; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S; Ai, H; Beausang, C; Cridder, B

    2005-12-29

    The authors have deduced the cross section for {sup 237}U(n,f) over an equivalent neutron energy range from 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions: {sup 238}U({alpha},{alpha}{prime}f) and {sup 236}U({alpha},{alpha}{prime}f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). Scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} and 131{sup o}.

  5. Development of surrogate correlation models to predict trace organic contaminant oxidation and microbial inactivation during ozonation.

    Science.gov (United States)

    Gerrity, Daniel; Gamage, Sujanie; Jones, Darryl; Korshin, Gregory V; Lee, Yunho; Pisarenko, Aleksey; Trenholm, Rebecca A; von Gunten, Urs; Wert, Eric C; Snyder, Shane A

    2012-12-01

    The performance of ozonation in wastewater depends on water quality and the ability to form hydroxyl radicals (·OH) to meet disinfection or contaminant transformation objectives. Since there are no on-line methods to assess ozone and ·OH exposure in wastewater, many agencies are now embracing indicator frameworks and surrogate monitoring for regulatory compliance. Two of the most promising surrogate parameters for ozone-based treatment of secondary and tertiary wastewater effluents are differential UV(254) absorbance (ΔUV(254)) and total fluorescence (ΔTF). In the current study, empirical correlations for ΔUV(254) and ΔTF were developed for the oxidation of 18 trace organic contaminants (TOrCs), including 1,4-dioxane, atenolol, atrazine, bisphenol A, carbamazepine, diclofenac, gemfibrozil, ibuprofen, meprobamate, naproxen, N,N-diethyl-meta-toluamide (DEET), para-chlorobenzoic acid (pCBA), phenytoin, primidone, sulfamethoxazole, triclosan, trimethoprim, and tris-(2-chloroethyl)-phosphate (TCEP) (R(2) = 0.50-0.83) and the inactivation of three microbial surrogates, including Escherichia coli, MS2, and Bacillus subtilis spores (R(2) = 0.46-0.78). Nine wastewaters were tested in laboratory systems, and eight wastewaters were evaluated at pilot- and full-scale. A predictive model for OH exposure based on ΔUV(254) or ΔTF was also proposed.

  6. Validation of (n,gamma) surrogate methods and the 95Mo(n,gamma) reaction

    Science.gov (United States)

    Cizewski, J. A.; Adekola, A. S.; Howard, M. E.; Manning, B.; Ratkiewicz, A.; Couture, A. J.; Devlin, M.; Fotiades, N.; Nelson, R. O.; O'Donnell, J. M.; Peters, W. A.; Burke, J. T.; Escher, J. E.; Hatarik, R.; Scielzo, N. D.

    2012-10-01

    Neutron capture on unstable isotopes is important for the synthesis of heavy elements through both the r and s processes and so for nuclear energy and stockpile stewardship science. However, it is difficult to measure these cross sections directly with neutrons on targets that live less than about 100 days. Therefore, there has been a concerted effort by many groups [J.E. Escher RMP 84, 353 (2012) and references therein] to develop a validated surrogate reaction for neutron capture, a reaction that predominantly occurs at relatively low neutron energies where the angular momentum dependence needs to be taken into account. Many of the surrogate approaches use partial cross sections of discrete low-lying gamma-ray transitions to deduce the decay of the compound nucleus. Yet there have been very few measurements of the intensity of these discrete transitions in (n,g) as a function of neutron energy up to 200 keV. As part of the program to validate (d,pg) as a surrogate for neutron capture, we have recently measured the intensity of yrast transitions in 96Mo populated by the 95Mo(n,g) reaction with a small array of HPGe detectors on FP12 at the Lujan Center of LANSCE. Preliminary results of these measurements and the status of the (d,pg) validation program with 95Mo targets will be presented.

  7. Kriging-based generation of optimal databases as forward and inverse surrogate models

    Science.gov (United States)

    Bilicz, S.; Lambert, M.; Gyimóthy, Sz

    2010-07-01

    Numerical methods are used to simulate mathematical models for a wide range of engineering problems. The precision provided by such simulators is usually fine, but at the price of computational cost. In some applications this cost might be crucial. This leads us to consider cheap surrogate models in order to reduce the computation time still meeting the precision requirements. Among all available surrogate models, we deal herein with the generation of an 'optimal' database of pre-calculated results combined with a simple interpolator. A database generation approach is investigated which is intended to achieve an optimal sampling. Such databases can be used for the approximate solution of both forward and inverse problems. Their structure carries some meta-information about the involved physical problem. In the case of the inverse problem, an approach for predicting the uncertainty of the solution (due to the applied surrogate model and/or the uncertainty of the measured data) is presented. All methods are based on kriging—a stochastic tool for function approximation. Illustrative examples are drawn from eddy current non-destructive evaluation.

  8. Ignition of alkane-rich FACE gasoline fuels and their surrogate mixtures

    KAUST Repository

    Sarathy, Mani

    2015-01-01

    Petroleum derived gasoline is the most used transportation fuel for light-duty vehicles. In order to better understand gasoline combustion, this study investigated the ignition propensity of two alkane-rich FACE (Fuels for Advanced Combustion Engines) gasoline test fuels and their corresponding PRF (primary reference fuel) blend in fundamental combustion experiments. Shock tube ignition delay times were measured in two separate facilities at pressures of 10, 20, and 40 bar, temperatures from 715 to 1500 K, and two equivalence ratios. Rapid compression machine ignition delay times were measured for fuel/air mixtures at pressures of 20 and 40 bar, temperatures from 632 to 745 K, and two equivalence ratios. Detailed hydrocarbon analysis was also performed on the FACE gasoline fuels, and the results were used to formulate multi-component gasoline surrogate mixtures. Detailed chemical kinetic modeling results are presented herein to provide insights into the relevance of utilizing PRF and multi-component surrogate mixtures to reproduce the ignition behavior of the alkane-rich FACE gasoline fuels. The two FACE gasoline fuels and their corresponding PRF mixture displayed similar ignition behavior at intermediate and high temperatures, but differences were observed at low temperatures. These trends were mimicked by corresponding surrogate mixture models, except for the amount of heat release in the first stage of a two-stage ignition events, when observed. © 2014 The Combustion Institute.

  9. Crack Identification of Cantilever Plates Based on a Kriging Surrogate Model.

    Science.gov (United States)

    Gao, Haiyang; Guo, Xinglin; Ouyang, Huajiang; Han, Fang

    2013-10-01

    This work presents an effective method to identify the tip locations of an internal crack in cantilever plates based on a Kriging surrogate model. Samples of varying crack parameters (tip locations) and their corresponding root mean square (RMS) of random responses are used to construct the initial Kriging surrogate model. Moreover, the pseudo excitation method (PEM) is employed to speed up the spectral analysis. For identifying crack parameters based on the constructed Kriging model, a robust stochastic particle swarm optimization (SPSO) algorithm is adopted for enhancing the global searching ability. To improve the accuracy of the surrogate model without using extensive samples, a small number of samples are first used. Then an optimal point-adding process is carried out to reduce computational cost. Numerical studies of a cantilever plate with an internal crack are performed. The effectiveness and efficiency of this method are demonstrated by the identified results. The effect of initial sampling size on the precision of the identified results is also investigated.

  10. Using (d,pγ) as a Surrogate for Neutron Capture with ^75As

    Science.gov (United States)

    Peters, W. A.; Cizewski, J. A.; Hatarik, R.; O'Malley, P.; Vieira, D. J.; Jandel, M.; Wilhelmy, J. B.; Matei, C.; Bardayan, D. W.; Smith, M. S.; Pain, S. D.; Jones, K. L.; Moazen, B. H.; Chae, K. Y.; Kozub, R. L.; Shriner, J.; Blackmon, J. C.

    2008-10-01

    Arsenic is used as a radiochemical neutron fluence detector for nuclear reactions and other applications. The abundances of the residual isotopes ^73,74As allow one to calculate the total neutron activity through (n,2n) or (n,γ) reactions along the isotopic network chain. The neutron capture reaction cross sections used for these calculations cannot be directly measured for the radioactive isotopes, but the (d,pγ) reaction as a surrogate for the (n,γ) reaction can be measured. An experiment at Oak Ridge National Laboratory using As beams in inverse kinematics and a deuterated target will first measure the ^75As(d,pγ) reaction with stable beam to test the efficacy of our surrogate experimental techniques. With a tight geometry, eight ORRUBA silicon-strip detectors will detect recoil protons in coincidence with γ-rays detected by four high-purity segmented Ge clover detectors. Status and future goals for the As(d,pγ) surrogate campaign will be presented.

  11. Synthetic aperture acoustic measurements of stationary suspended cinderblock and surrogate substitutes

    Science.gov (United States)

    Bishop, Steven; Woods, Teresa; Vignola, Joe; Judge, John; Soumekh, Mehrdad

    2009-05-01

    A synthetic aperture acoustic approach is used as a standoff method to assess material properties of a typical cinder block, referred to as a concrete masonry unit (CMU), and a variety of CMU surrogates. The objective is to identify anomalies in CMU wall surfaces. The acoustic specular return and phase change across the blocks are the fundamental measurements of interest. The CMU surrogates are created from commercially available closed cell expanding foam. Results from three test articles are presented that show potentially exploitable differences in terms of acoustic magnitude and acoustic phase response between the surrogates and typical CMUs. The test articles are; a typical CMU, a foam block, and a foam block with an embedded steel object. All test articles are similar in size and shape, and both foam blocks are covered in grout so that surface appearance closely matches that of a CMU. The results show that each of the test articles has characteristics that may be used for discrimination and anomaly detection.

  12. Upper and Lower Neck Loads in Belted Human Surrogates in Frontal Impacts

    Science.gov (United States)

    Yoganandan, Narayan; Pintar, Frank A.; Moore, Jason; Rinaldi, James; Schlick, Michael; Maiman, Dennis J.

    2012-01-01

    The upper and lower neck loads in the restrained Hybrid III dummy and Test Device for Human Occupant Restraint (THOR) were computed in simulated frontal impact sled tests at low, medium, and high velocities; repeatability performance of the two dummies were evaluated at all energy inputs; peak forces and moments were compared with computed loads at the occipital condyles and cervical-thoracic junctions from tests using post mortem human surrogates (PMHS). A custom sled buck was used to position the surrogates. Repeated tests were conducted at each velocity for each dummy and sufficient time was allowed to elapse between the two experiments. The upper and lower neck forces and moments were determined from load cell measures and its locations with respect to the ends of the neck. Both dummies showed good repeatability for axial and shear forces and bending moments at all changes in velocity inputs. Morphological characteristics in the neck loading responses were similar in all surrogates, although the peak magnitudes of the variables differed. In general, the THOR better mimicked the PMHS response than the Hybrid III dummy, and factors such as neck design and chest compliance were attributed to the observed variations. While both dummies were not designed for use at the two extremes of the tested velocities, results from the present study indicate that, currently the THOR may be the preferred anthropomorphic testing device in crashworthiness research studies and full-scale vehicle tests at all velocities. PMID:23169123

  13. Measuring (n,f) cross sections of plutonium nuclei via the surrogate method

    Science.gov (United States)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Gell, K.; Good, E.; Tarlow, T.; Burke, J. T.; Casperson, R. J.; McCleskey, M.; Saastamoinen, A.; Cooper, N.; Humby, P.

    2012-10-01

    Neutron-induced cross section measurements of exotic nuclei provide a significant experimental challenge due to the need for radioactive targets and high neutron fluxes. Over the past few years the surrogate method has been shown to provide a means of indirectly measuring certain neutron-induced cross sections. Recent results benchmarking (p,t-f) and (p,d-f) reactions as surrogates for (n,f) cross section measurements in uranium nuclei show good agreement with literature data [1]. Building on this work, the use of (p,t-f) and (p,d-f) reactions has very recently been extended to surrogate measurements of the poorly established ^236Pu(n,f) and ^237Pu(n,f) cross sections. The experiment was performed at Texas A&M University using a 30 MeV proton beam from the K150 cyclotron, incident on ^239Pu and ^235U targets. Charged particle-fission and charged particle-γ coincidence data were collected using the combined silicon telescope and γ-ray array: STARLiTe. Preliminary results will be presented. This work was supported by DoE Grant Numbers: DE-FG52-09 NA29454 and DE-FG02-05 ER41379 (UR) and DE-AC52-07 NA27344 (LLNL).[4pt] [1] R.O. Hughes et al., PRC 85, 024613 (2012).

  14. Surrogate endpoints for EDSS worsening in multiple sclerosis. A meta-analytic approach.

    Science.gov (United States)

    Sormani, M P; Bonzano, L; Roccatagliata, L; Mancardi, G L; Uccelli, A; Bruzzi, P

    2010-07-27

    To evaluate whether the effects on potential surrogate endpoints, such as MRI markers and relapses, observed in trials of experimental treatments are able to predict the effects of these treatments on disability progression as defined in relapsing-remitting multiple sclerosis (RRMS) trials. We used a pooled analysis of all the published randomized controlled clinical trials in RRMS reporting data on Expanded Disability Status Scale (EDSS) worsening and relapses or MRI lesions or both. We extracted data on relapses, MRI lesions, and the proportion of progressing patients. A regression analysis weighted on trial size and duration was performed to study the relationship between the treatment effect observed in each trial on relapses and MRI lesions and the observed treatment effect on EDSS worsening. A set of 19 randomized double-blind controlled trials in RRMS were identified, for a total of 44 arms, 25 contrasts, and 10,009 patients. A significant correlation was found between the effect of treatments on relapses and the effect of treatments on EDSS worsening: the adjusted R(2) value of the weighted regression was 0.71. The correlation between the treatment effect on MRI lesions and EDSS worsening was slightly weaker (R(2) = 0.57) but significant. These findings support the use of commonly used surrogate markers of EDSS worsening as endpoints in multiple sclerosis clinical trials. Further research is warranted to validate surrogate endpoints at the individual level rather than at the trial level, to draw important conclusions in the management of the individual patient.

  15. Multi-objective optimisation of a vehicle energy absorption structure based on surrogate model

    Institute of Scientific and Technical Information of China (English)

    谢素超; 周辉

    2014-01-01

    In order to optimize the crashworthy characteristic of energy-absorbing structures, the surrogate models of specific energy absorption (SEA) and ratio of SEA to initial peak force (REAF) with respect to the design parameters were respectively constructed based on surrogate model optimization methods (polynomial response surface method (PRSM) and Kriging method (KM)). Firstly, the sample data were prepared through the design of experiment (DOE). Then, the test data models were set up based on the theory of surrogate model, and the data samples were trained to obtain the response relationship between the SEA & REAF and design parameters. At last, the structure optimal parameters were obtained by visual analysis and genetic algorithm (GA). The results indicate that the KM, where the local interpolation method is used in Gauss correlation function, has the highest fitting accuracy and the structure optimal parameters are obtained as: the SEA of 29.8558 kJ/kg (corresponding toa=70 mm andt= 3.5 mm) and REAF of 0.2896 (corresponding toa=70 mm andt=1.9615 mm). The basis function of the quartic PRSM with higher order than that of the quadratic PRSM, and the mutual influence of the design variables are considered, so the fitting accuracy of the quartic PRSM is higher than that of the quadratic PRSM.

  16. Single-site Lennard-Jones models via polynomial chaos surrogates of Monte Carlo molecular simulation

    KAUST Repository

    Kadoura, Ahmad Salim

    2016-06-01

    In this work, two Polynomial Chaos (PC) surrogates were generated to reproduce Monte Carlo (MC) molecular simulation results of the canonical (single-phase) and the NVT-Gibbs (two-phase) ensembles for a system of normalized structureless Lennard-Jones (LJ) particles. The main advantage of such surrogates, once generated, is the capability of accurately computing the needed thermodynamic quantities in a few seconds, thus efficiently replacing the computationally expensive MC molecular simulations. Benefiting from the tremendous computational time reduction, the PC surrogates were used to conduct large-scale optimization in order to propose single-site LJ models for several simple molecules. Experimental data, a set of supercritical isotherms, and part of the two-phase envelope, of several pure components were used for tuning the LJ parameters (ε, σ). Based on the conducted optimization, excellent fit was obtained for different noble gases (Ar, Kr, and Xe) and other small molecules (CH4, N2, and CO). On the other hand, due to the simplicity of the LJ model used, dramatic deviations between simulation and experimental data were observed, especially in the two-phase region, for more complex molecules such as CO2 and C2 H6.

  17. The neutron within the deuteron as a surrogate for neutron-induced reactions

    CERN Document Server

    Bertulani, C A; Hussein, M S; Shubhchintak,; Tran, Viet Nhan Hao

    2016-01-01

    We propose the use of neutron poisons in reactions induced by radioactive beams as a test of theoretical models aiming to relate neutron capture in nuclei with neutron surrogate reactions such as (d,p) reactions. We exploit the approximations necessary to obtain a direct relation between the two reactions; surrogate vs. neutron capture. We also show how this is intimately related to the momentum distribution of the neutron within the deuteron. The models we use are based on the theory of inclusive breakup reactions commonly employed in the treatment of incomplete fusion and surrogate method. Such theories were developed in the 80's by Ichimura, Autern and Vincent [Phys. Rev. C 32, 431 (1985)], Udagawa and Tamura [Phys. Rev. C 24, 1348 (1981)] and Hussein and McVoy [Nucl. Phys. A 445, 124 (1985)]. We use these theories to derive an expression for the proton yield in the reaction A(d,p)B. The capture reaction $n + A \\rightarrow B$ is then extracted using reasonable approximations. By recalling an old method pro...

  18. Deducing the 237U(n,f) cross-section using the Surrogate Ratio Method

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J T; Bernstein, L A; Escher, J; Ahle, L; Church, J A; Dietrich, F; Moody, K J; Norman, E B; Phair, L W; Fallon, P; Clark, R; Delaplanque, M; Descovich, M; Cromaz, M; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Stephens, F S

    2005-08-16

    The authors have deduced the {sup 237}U(n,f) cross-section over an equivalent neutron energy range of 0 to 20 MeV using the Surrogate Ratio method. A 55 MeV {sup 4}He{sup 2+} beam from the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory was used to induce fission in the following reactions {sup 238}U({alpha},{alpha}'f) and {sup 236}U({alpha},{alpha}'f). The {sup 238}U reaction was a surrogate for {sup 237}U(n,f) and the {sup 236}U reaction was used as a surrogate for {sup 235}U(n,f). The energies of the scattered alpha particles were detected in a fully depleted segmented silicon telescope array (STARS) over an angle range of 35{sup o} to 60{sup o} with respect to the beam axis. The fission fragments were detected in a third independent silicon detector located at backward angles between 106{sup o} to 131{sup o}.

  19. Asymptotic ideal observers and surrogate figures of merit for signal detection with list-mode data.

    Science.gov (United States)

    Clarkson, Eric

    2012-10-01

    The asymptotic form for the likelihood ratio is derived for list-mode data generated by an imaging system viewing a possible signal in a randomly generated background. This calculation provides an approximation to the likelihood ratio that is valid in the limit of large number of list entries, i.e., a large number of photons. These results are then used to derive surrogate figures of merit, quantities that are correlated with ideal-observer performance on detection tasks, as measured by the area under the receiver operating characteristic curve, but are easier to compute. A key component of these derivations is the determination of asymptotic forms for the Fisher information for the signal amplitude in the limit of a large number of counts or a long exposure time. This quantity is useful in its own right as a figure of merit (FOM) for the task of estimating the signal amplitude. The use of the Fisher information in detection tasks is based on the fact that it provides an approximation for ideal-observer detectability when the signal is weak. For both the fixed-count and fixed-time cases, four surrogate figures of merit are derived. Two are based on maximum likelihood reconstructions; one uses the characteristic functional of the random backgrounds. The fourth surrogate FOM is identical in the two cases and involves an integral over attribute space for each of a randomly generated sequence of backgrounds.

  20. Surrogate models of precessing numerical relativity gravitational waveforms for use in parameter estimation

    Science.gov (United States)

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

    2016-03-01

    We are now in the advanced detector era of gravitational wave astronomy, and the merger of two black holes (BHs) is one of the most promising sources of gravitational waves that could be detected on earth. To infer the BH masses and spins, the observed signal must be compared to waveforms predicted by general relativity for millions of binary configurations. Numerical relativity (NR) simulations can produce accurate waveforms, but are prohibitively expensive to use for parameter estimation. Other waveform models are fast enough but may lack accuracy in portions of the parameter space. Numerical relativity surrogate models attempt to rapidly predict the results of a NR code with a small or negligible modeling error, after being trained on a set of input waveforms. Such surrogate models are ideal for parameter estimation, as they are both fast and accurate, and have already been built for the case of non-spinning BHs. Using 250 input waveforms, we build a surrogate model for waveforms from the Spectral Einstein Code (SpEC) for a subspace of precessing systems.

  1. Novel brain-penetrating oximes for reactivation of cholinesterase inhibited by sarin and VX surrogates.

    Science.gov (United States)

    Chambers, Janice E; Meek, Edward C; Chambers, Howard W

    2016-06-01

    Current oxime reactivators for organophosphate-inhibited cholinesterase (ChE) do not effectively cross the blood-brain barrier and therefore cannot restore brain ChE activity in vivo. Our laboratories have studied highly relevant sarin and VX surrogates, which differ from their respective nerve agents only in the leaving group and thereby leave ChE phosphylated with the same chemical moiety as sarin and VX. Our laboratories have developed novel substituted phenoxyalkyl pyridinium oximes that lead to reduced ChE inhibition in the brains of rats challenged with a high sublethal dosage of the sarin surrogate, whereas 2-PAM did not, using a paradigm designed to demonstrate brain penetration. In addition, treatment of rats with these novel oximes is associated with attenuation of seizure-like behavior compared to rats treated with 2-PAM, providing additional evidence that the oximes penetrate the blood-brain barrier. Further, some of the oximes provided 24-h survival superior to 2-PAM, and shortened the duration of seizure-like behavior when rats were challenged with lethal dosages of the sarin and VX surrogates, providing additional support for the conclusion that these oximes penetrate the brain.

  2. Effective-one-body waveforms for binary neutron stars using surrogate models

    CERN Document Server

    Lackey, Benjamin D; Galley, Chad R; Meidam, Jeroen; Broeck, Chris Van Den

    2016-01-01

    Gravitational-wave observations of binary neutron star systems can provide information about the masses, spins, and structure of neutron stars. However, this requires accurate and computationally efficient waveform models that take <1s to evaluate for use in Bayesian parameter estimation codes that perform 10^7 - 10^8 waveform evaluations. We present a surrogate model of a nonspinning effective-one-body waveform model with l = 2, 3, and 4 tidal multipole moments that reproduces waveforms of binary neutron star numerical simulations up to merger. The surrogate is built from compact sets of effective-one-body waveform amplitude and phase data that each form a reduced basis. We find that 12 amplitude and 7 phase basis elements are sufficient to reconstruct any binary neutron star waveform with a starting frequency of 10Hz. The surrogate has maximum errors of 3.8% in amplitude (0.04% excluding the last 100M before merger) and 0.043 radians in phase. The version implemented in the LIGO Algorithm Library takes ~...

  3. The ionic strength effect on microcystin and natural organic matter surrogate adsorption onto PAC.

    Science.gov (United States)

    Campinas, Margarida; Rosa, Maria João

    2006-07-15

    This work aims to contribute to a better understanding of the ionic strength effect on microcystin and natural organic matter (NOM) surrogate adsorption by analyzing the importance of adsorbate molecular size, and surface concentration. Adsorption kinetics and/or isotherms were performed on PAC Norit SA-UF for four microcystin variants (MC-LR, MC-LY, MC-LW, MC-LF), and three NOM surrogates (salicylic acid (SA), tannic acid (TA), Aldrich humic acid (AHA)) at different solution ionic strengths. Results showed that the ionic strength effect depends upon the adsorbate surface concentration, cation charge (mono or divalent), and adsorbate molecular size. Potassium seemed not to affect the MC-LR adsorption, while calcium enhanced MC-LR kinetics and adsorption capacity. K+ and, particularly, Ca2+ improved the adsorption kinetics of the other microcystin variants. For identical surface concentration and ionic strength, the impact of K+ and Ca2+ on NOM surrogates depended on the adsorbate molecular size: K+ effect was only observed for AHA, whereas Ca2+ caused no effect on SA adsorption, slightly enhanced TA adsorption, and greatly enhanced AHA adsorption. MC-LR isotherms with two salt concentrations (KCl or CaCl2) indicated that, for the studied range of equilibrium surface concentration (5.3-18.7 mg/g), an enhanced adsorption regime prevails, and no transition regime was observed.

  4. Cross sections for neutron capture from surrogate measurements: An examination of Weisskopf-Ewing and ratio approximations

    CERN Document Server

    Escher, Jutta E

    2010-01-01

    Motivated by the renewed interest in the surrogate nuclear reactions approach, an indirect method for determining compound-nuclear reaction cross sections, the prospects for determining (n, gamma) cross sections for deformed rare-earth and actinide nuclei are investigated. A nuclear-reaction model is employed to simulate physical quantities that are typically measured in surrogate experiments and used to assess the validity of the Weisskopf-Ewing and ratio approximations, which are typically employed in the analysis of surrogate reactions. The expected accuracy of (n,gamma) cross sections extracted from typical surrogate measurements is discussed and limitations of the approximate methods are illustrated. Suggestions for moving beyond presently-employed approximations are made.

  5. Conceptions of Parents, Conceptions of Self, and Conceptions of God.

    Science.gov (United States)

    Buri, John R.; Mueller, Rebecca A.

    Different theorists have suggested that an individual's view of God may be related to one's view of one's father, one's mother, or one's self. A study was conducted to examine the relationship of college students' conceptions of the wrathfulness-kindliness of God to their conceptions of their father's and mother's permissiveness, authoritarianism,…

  6. Sediment transport and evaluation of sediment surrogate ratings in the Kootenai River near Bonners Ferry, Idaho, Water Years 2011–14

    Science.gov (United States)

    Wood, Molly S.; Fosness, Ryan L.; Etheridge, Alexandra B.

    2015-12-14

    The Kootenai River white sturgeon (Acipenser transmontanus) and other native fish species are culturally important to the Kootenai Tribe of Idaho, but their habitat and recruitment have been affected by anthropogenic changes to the river. Although the interconnections among anthropogenic changes and their impacts on fish are complex, the Kootenai Tribe of Idaho, in cooperation with other agencies, has been trying to understand and promote native fish recruitment through the development and implementation of the Kootenai River Habitat Restoration Program. As part of this effort, the U.S. Geological Survey collected sediment and streamflow information and evaluated use of acoustic backscatter as a sediment surrogate for estimating continuous suspended-sediment concentration at three sites in the Kootenai River white sturgeon critical habitat during water years 2011–14.

  7. Coastal aquifer management based on surrogate models and multi-objective optimization

    Science.gov (United States)

    Mantoglou, A.; Kourakos, G.

    2011-12-01

    The demand for fresh water in coastal areas and islands can be very high, especially in summer months, due to increased local needs and tourism. In order to satisfy demand, a combined management plan is proposed which involves: i) desalinization (if needed) of pumped water to a potable level using reverse osmosis and ii) injection of biologically treated waste water into the aquifer. The management plan is formulated into a multiobjective optimization framework, where simultaneous minimization of economic and environmental costs is desired; subject to a constraint to satisfy demand. The method requires modeling tools, which are able to predict the salinity levels of the aquifer in response to different alternative management scenarios. Variable density models can simulate the interaction between fresh and saltwater; however, they are computationally intractable when integrated in optimization algorithms. In order to alleviate this problem, a multi objective optimization algorithm is developed combining surrogate models based on Modular Neural Networks [MOSA(MNN)]. The surrogate models are trained adaptively during optimization based on a Genetic Algorithm. In the crossover step of the genetic algorithm, each pair of parents generates a pool of offspring. All offspring are evaluated based on the fast surrogate model. Then only the most promising offspring are evaluated based on the exact numerical model. This eliminates errors in Pareto solution due to imprecise predictions of the surrogate model. Three new criteria for selecting the most promising offspring were proposed, which improve the Pareto set and maintain the diversity of the optimum solutions. The method has important advancements compared to previous methods, e.g. alleviation of propagation of errors due to surrogate model approximations. The method is applied to a real coastal aquifer in the island of Santorini which is a very touristy island with high water demands. The results show that the algorithm

  8. Performance comparison of several response surface surrogate models and ensemble methods for water injection optimization under uncertainty

    Science.gov (United States)

    Babaei, Masoud; Pan, Indranil

    2016-06-01

    In this paper we defined a relatively complex reservoir engineering optimization problem of maximizing the net present value of the hydrocarbon production in a water flooding process by controlling the water injection rates in multiple control periods. We assessed the performance of a number of response surface surrogate models and their ensembles which are combined by Dempster-Shafer theory and Weighted Averaged Surrogates as found in contemporary literature works. Most of these ensemble methods are based on the philosophy that multiple weak learners can be leveraged to obtain one strong learner which is better than the individual weak ones. Even though these techniques have been shown to work well for test bench functions, we found them not offering a considerable improvement compared to an individually used cubic radial basis function surrogate model. Our simulations on two and three dimensional cases, with varying number of optimization variables suggest that cubic radial basis functions-based surrogate model is reliable, outperforms Kriging surrogates and multivariate adaptive regression splines, and if it does not outperform, it is rarely outperformed by the ensemble surrogate models.

  9. The effects of post-exposure smallpox vaccination on clinical disease presentation: addressing the data gaps between historical epidemiology and modern surrogate model data.

    Science.gov (United States)

    Keckler, M Shannon; Reynolds, Mary G; Damon, Inger K; Karem, Kevin L

    2013-10-25

    Decades after public health interventions - including pre- and post-exposure vaccination - were used to eradicate smallpox, zoonotic orthopoxvirus outbreaks and the potential threat of a release of variola virus remain public health concerns. Routine prophylactic smallpox vaccination of the public ceased worldwide in 1980, and the adverse event rate associated with the currently licensed live vaccinia virus vaccine makes reinstatement of policies recommending routine pre-exposure vaccination unlikely in the absence of an orthopoxvirus outbreak. Consequently, licensing of safer vaccines and therapeutics that can be used post-orthopoxvirus exposure is necessary to protect the global population from these threats. Variola virus is a solely human pathogen that does not naturally infect any other known animal species. Therefore, the use of surrogate viruses in animal models of orthopoxvirus infection is important for the development of novel vaccines and therapeutics. Major complications involved with the use of surrogate models include both the absence of a model that accurately mimics all aspects of human smallpox disease and a lack of reproducibility across model species. These complications limit our ability to model post-exposure vaccination with newer vaccines for application to human orthopoxvirus outbreaks. This review seeks to (1) summarize conclusions about the efficacy of post-exposure smallpox vaccination from historic epidemiological reports and modern animal studies; (2) identify data gaps in these studies; and (3) summarize the clinical features of orthopoxvirus-associated infections in various animal models to identify those models that are most useful for post-exposure vaccination studies. The ultimate purpose of this review is to provide observations and comments regarding available model systems and data gaps for use in improving post-exposure medical countermeasures against orthopoxviruses.

  10. Improved method for quantifying the avicide 3-chloro-p-toluidine hydrochloride in bird tissues using a deuterated surrogate/GC/MS method

    Science.gov (United States)

    Stahl, R.S.; Custer, T.W.; Pochop, P.A.; Johnston, J.J.

    2002-01-01

    A method using a deuterated surrogate of the avicide 3-chloro-p-toluidine hydrochloride (CPTH) was developed to quantify the CPTH residues in the gastrointestinal (Gl) tract and breast muscle tissues in birds collected in CPTH-baited sunflower and rice fields. This method increased the range of a previous surrogate/gas chromatography/mass spectroscopy method from 0-2 to 0-20mug/g in tissue samples and greatly simplified the extraction procedure. The modified method also sought to increase recoveries over a range of matrix effects introduced by analyzing tissues from birds collected in the field, where the GI tract contents would be affected by varying diet. The new method was used to determine the CPTH concentration In GI tract samples fortified with CPTH-treated rice bait to simulate the consumption of varying amounts of treated bait by two nontargeted bird species, pigeon (Columbia livia) and house sparrow (Passer domesticus). The new method was then used to examine the CPTH concentrations in the gizzard contents of the targeted bird species, red-winged black bird (Agelaius phoeniceus) and brown-headed cowbird (Molothrus ater) that were collected after feeding at a treated bait site. The method proved sufficiently sensitive to quantify CPTH in the breast muscle tissues and the gizzard contents of red-winged blackbirds and brown-headed cowbirds during an operational baiting program. The levels of CPTH determined for these birds in both tissue samples were determined to be highly correlated. The appearance of CPTH in the breast muscle tissue immediately after feeding was not anticipated. The potential secondary hazard posed by the targeted birds to potential scavengers and predators was also evaluated.

  11. Serial concept maps: tools for concept analysis.

    Science.gov (United States)

    All, Anita C; Huycke, LaRae I

    2007-05-01

    Nursing theory challenges students to think abstractly and is often a difficult introduction to graduate study. Traditionally, concept analysis is useful in facilitating this abstract thinking. Concept maps are a way to visualize an individual's knowledge about a specific topic. Serial concept maps express the sequential evolution of a student's perceptions of a selected concept. Maps reveal individual differences in learning and perceptions, as well as progress in understanding the concept. Relationships are assessed and suggestions are made during serial mapping, which actively engages the students and faculty in dialogue that leads to increased understanding of the link between nursing theory and practice. Serial concept mapping lends itself well to both online and traditional classroom environments.

  12. Experimental and numerical studies of burning velocities and kinetic modeling for practical and surrogate fuels

    Science.gov (United States)

    Zhao, Zhenwei

    To help understand the fuel oxidation process in practical combustion environments, laminar flame speeds and high temperature chemical kinetic models were studied for several practical fuels and "surrogate" fuels, such as propane, dimethyl ether (DME), and primary reference fuel (PRF) mixtures, gasoline and n-decane. The PIV system developed for the present work is described. The general principles for PIV measurements are outlined and the specific considerations are also reported. Laminar flame speeds were determined for propane/air over a range of equivalence ratios at initial temperature of 298 K, 500 K and 650 K and atmospheric pressure. Several data sets for propane/air laminar flame speeds with N 2 dilution are also reported. These results are compared to the literature data collected at the same conditions. The propane flame speed is also numerically calculated with a detailed kinetic model and multi component diffusion, including Soret effects. This thesis also presents experimentally determined laminar flame speeds for primary reference fuel (PRF) mixtures of n-heptane/iso-octane and real gasoline fuel at different initial temperature and at atmospheric pressure. Nitrogen dilution effects on the laminar flame speed are also studied for selected equivalence ratios at the same conditions. A minimization of detailed kinetic model for PRF mixtures on laminar flame speed conditions was performed and the measured flame speeds were compared with numerical predictions using this model. The measured laminar flame speeds of n-decane/air mixtures at 500 K and at atmospheric pressure with and without dilution were determined. The measured flame speeds are significantly different that those predicted using existing published kinetic models, including a model validated previously against high temperature data from flow reactor, jet-stirred reactor, shock tube ignition delay, and burner stabilized flame experiments. A significant update of this model is described which

  13. The kinetic and thermodynamic sorption and stabilization of multiwalled carbon nanotubes in natural organic matter surrogate solutions: the effect of surrogate molecular weight.

    Science.gov (United States)

    Li, Tingting; Lin, Daohui; Li, Lu; Wang, Zhengyu; Wu, Fengchang

    2014-03-01

    Styrene sulfonate (SS) and polystyrene sulfonates (PSSs) were used as surrogates of natural organic matter to study the effect of molecular weight (from 206.2 to 70,000 Da) on their sorption by a multiwalled carbon nanotube (MWCNT) and an activated carbon (AC) and on their stabilization of MWCNT suspension. Results indicate that surface-diffusion through the liquid-sorbent boundary was the rate-controlling step of the kinetic sorption of both MWCNTs and AC, and surface-occupying and pore-filling mechanisms respectively dominated the thermodynamic sorption of MWCNTs and AC. Sorption rates and capacities of MWCNTs and AC in molecular concentration of SS and PSS decreased with increasing molecular weight. The PSSs but not SS facilitated the stabilization of MWCNT suspension because of the increased electrosteric repulsion. The PSSs with more monomers had greater capabilities to stabilize the MWCNT suspension, but the capabilities were comparable after being normalized by the total monomer number.

  14. Modern Social Science Concepts, Proportionate Reciprocity, Modesty, and Democracy

    Directory of Open Access Journals (Sweden)

    Gerasimos T. SOLDATOS

    2014-06-01

    Full Text Available Proportionate Reciprocity, Modesty, and Democracy, are the key concepts in Aristotle’s economics of exchange. The following correspondence of these concepts with modern social science may be contemplated: (a Ideally, reciprocal justice in bilateral bargaining to minimize expenditure given utility levels results in Pareto-efficient, envy-free, equitable outcomes. (b Practically, bargaining under the threat or actual recontracting may act as a surrogate of reciprocal justice, leading to an N-person contract topology. (c But, recontracting is subject to practical limitations too, in which case near-reciprocal justice/general equilibrium outcomes may be fostered if, as a surrogate of recontracting, modesty in interaction is exhibited in an evolutionarily-stable-strategy fashion. (d That is, incomplete recontracting amounts to asymmetric agent-type information, which in turn lays the ground for injustices; the same lack of information prevents rectificatory justice from being efficient and hence, modesty can be efficient only if it operates as a social norm and hence, only in a modest polity, which can be no other than democracy.

  15. Use of micafungin as a surrogate marker to predict susceptibility and resistance to caspofungin among 3,764 clinical isolates of Candida by use of CLSI methods and interpretive criteria.

    Science.gov (United States)

    Pfaller, Michael A; Messer, Shawn A; Diekema, Daniel J; Jones, Ronald N; Castanheira, Mariana

    2014-01-01

    Due to unacceptably high interlaboratory variation in caspofungin MIC values, we evaluated the use of micafungin as a surrogate marker to predict the susceptibility of Candida spp. to caspofungin using reference methods and species-specific interpretive criteria. The MIC results for 3,764 strains of Candida (eight species), including 73 strains with fks mutations, were used. Caspofungin MIC values and species-specific interpretive criteria were compared with those of micafungin to determine the percent categorical agreement (%CA) and very major error (VME), major error (ME), and minor error rates as well as their ability to detect fks mutant strains of Candida albicans (11 mutants), Candida tropicalis (4 mutants), Candida krusei (3 mutants), and Candida glabrata (55 mutants). Overall, the %CA was 98.8% (0.2% VMEs and MEs, 0.8% minor errors) using micafungin as the surrogate marker. Among the 60 isolates of C. albicans (9 isolates), C. tropicalis (5 isolates), C. krusei (2 isolates), and C. glabrata (44 isolates) that were nonsusceptible (either intermediate or resistant) to both caspofungin and micafungin, 54 (90.0%) contained a mutation in fks1 or fks2. An additional 10 C. glabrata mutants, two C. albicans mutants, and one mutant each of C. tropicalis and C. krusei were classified as susceptible to both antifungal agents. Using the epidemiological cutoff values (ECVs) of 0.12 μg/ml for caspofungin and 0.03 μg/ml for micafungin to differentiate wild-type (WT) from non-WT strains of C. glabrata, 80% of the C. glabrata mutants were non-WT for both agents (96% concordance). Micafungin may serve as an acceptable surrogate marker for the prediction of susceptibility and resistance of Candida to caspofungin.

  16. Evolution of N-species Kimura/voter models towards criticality, a surrogate for general models of accidental pathogens

    Science.gov (United States)

    Ghaffari, Peyman; Stollenwerk, Nico

    2012-09-01

    In models for accidental pathogens, with the paradigmatic epidemiological system of bacterial meningitis, there was evolution towards states exhibiting critical fluctuations with power law behaviour observed [1]. This is a model with many possibly pathogenic strains essentially evolving independently to low pathogenicity. A first and previous study had shown that in the limit of vanishing pathogenicity there are critical fluctuations with power law distributions observed, already when only two strains interact [2]. This earlier version of a two strain model was very recently reinvestigated [3] and named as Stollenwerk-Jansen model (SJ). Muñoz et al. demonstrated that this two-strain model for accidental pathogens is in the universality class of the so-called voter model. Though this model clearly shows criticality, its control parameter, the pathogenicity, is not self-tuning towards criticality. However, the multi-strain version mentioned above [1] is well evolving towards criticality, as well as a spatially explicit version of this, shown in [4] p. 155. These models of multi-strain type including explicitly mutations of the pathogenicity can be called SJ-models of type II [5]. Since the original epidemiological model is of SIRYX-type, the evolution to zero pathogenicity is slow and perturbed by large population noise. In the present article we now show on the basis of the notion of the voter-model universality classes the evolution of n-voter models with mutaion towards criticality, now much less perturbed by population noise, hence demonstrating a clear mechanism of self-organized criticality in the sense of [6, 7]. The present results have wide implications for many diseases in which a large proportion of infections is asymptomatic, meaning that the system has already evolved towards an average low pathogenicity. This holds not only for the original paradigmatic case of bacterial meningitis, but was reecently also suggested for example for dengue fever (DENFREE project).

  17. Evaluation of Common Eider as a Surrogate species for Barrier Island Nesting Waterfowl in the Beaufort Sea: Annual Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a required report on work done in 2015 toward producing a report on the abundance, demographics, and potential limiting factors of common eider breeding on...

  18. A new formulation of physical surrogates of FACE A gasoline fuel based on heating and evaporation characteristics

    KAUST Repository

    Elwardani, Ahmed Elsaid

    2016-02-19

    The US Department of Energy has formulated various sets of gasoline fuels, called fuels for advanced combustion engines (FACE), which are consistent in composition and properties. The analysis of heating and evaporation of FACE A gasoline fuel (paraffin-rich) is studied by replacing the 66 components with 19 components to represent this fuel. The reduction in the number of components is based on merging components from the same chemical groups and having the same chemical formula, which have very close thermophysical properties; the components with the highest initial compositions are chosen to be the representative components. Modelling of heating and evaporation of FACE A gasoline fuel and various surrogates is carried out based on the effective thermal conductivity/effective diffusivity model (ETC/ED). The model takes into account the effect of finite liquid thermal conductivity, finite liquid mass diffusivity and recirculation inside the droplets due to their non-zero velocities relative to the ambient air. Four surrogates of FACE A found in the literature are used in the analysis. These surrogates include the five component surrogate chosen for its ability to match the ignition delay time of the FACE A gasoline fuel (Surr1), the primary reference fuel surrogate (PRF84) that matches the research octane number (RON) of FACE A, the one that matches hydrogen-to-carbon ratio (H/C), RON, density and distillation curve with FACE A (Surr2), and the one that matches the RON based on mole fraction linear blending (Surr3). It is shown that these surrogates cannot predict adequately the time evolution of surface temperatures and radii of FACE A droplets. New \\'physical\\' surrogates with 8, 7 and 6 components (Surr4, Surr5, and Surr6) are introduced to match the evaporation characteristics of FACE A. It is found that Surr5 (7 components surrogate) can predict droplet lifetime and time evolution of surface temperature of a FACE A droplet with errors of up to 5% and 0

  19. Invasive Species

    Science.gov (United States)

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  20. An evaluation of culture results during treatment for tuberculosis as surrogate endpoints for treatment failure and relapse.

    Directory of Open Access Journals (Sweden)

    Patrick P J Phillips

    Full Text Available It is widely acknowledged that new regimens are urgently needed for the treatment of tuberculosis. The primary endpoint in the Phase III trials is a composite outcome of failure at the end of treatment or relapse after stopping treatment. Such trials are usually both long and expensive. Valid surrogate endpoints measured during or at the end of treatment could dramatically reduce both the time and cost of assessing the effectiveness of new regimens. The objective of this study was to evaluate sputum culture results on solid media during treatment as surrogate endpoints for poor outcome. Data were obtained from twelve randomised controlled trials conducted by the British Medical Research Council in the 1970s and 80s in East Africa and East Asia, consisting of 6974 participants and 49 different treatment regimens. The month two culture result was shown to be a poor surrogate in East Africa but a good surrogate in Hong Kong. In contrast, the month three culture was a good surrogate in trials conducted in East Africa but not in Hong Kong. As well as differences in location, ethnicity and probable strain of Mycobacteria tuberculosis, Hong Kong trials more often evaluated regimens with rifampicin throughout and intermittent regimens, and patients in East African trials more often presented with extensive cavitation and were slower to convert to culture negative during treatment. An endpoint that is a summary measure of the longitudinal profile of culture results over time or that is able to detect the presence of M. tuberculosis later in treatment is more likely to be a better endpoint for a phase II trial than a culture result at a single time point and may prove to be an acceptable surrogate. More data are needed before any endpoint can be used as a surrogate in a confirmatory phase III trial.