Science.gov

Sample records for evolutional approach proven

  1. A proven approach for more effective software development and maintenance

    NASA Technical Reports Server (NTRS)

    Pajerski, Rose; Hall, Dana; Sinclair, Craig

    1994-01-01

    Modern space flight mission operations and associated ground data systems are increasingly dependent upon reliable, quality software. Critical functions such as command load preparation, health and status monitoring, communications link scheduling and conflict resolution, and transparent gateway protocol conversion are routinely performed by software. Given budget constraints and the ever increasing capabilities of processor technology, the next generation of control centers and data systems will be even more dependent upon software across all aspects of performance. A key challenge now is to implement improved engineering, management, and assurance processes for the development and maintenance of that software; processes that cost less, yield higher quality products, and that self-correct for continual improvement evolution. The NASA Goddard Space Flight Center has a unique experience base that can be readily tapped to help solve the software challenge. Over the past eighteen years, the Software Engineering Laboratory within the code 500 Flight Dynamics Division has evolved a software development and maintenance methodology that accommodates the unique characteristics of an organization while optimizing and continually improving the organization's software capabilities. This methodology relies upon measurement, analysis, and feedback much analogous to that of control loop systems. It is an approach with a time-tested track record proven through repeated applications across a broad range of operational software development and maintenance projects. This paper describes the software improvement methodology employed by the Software Engineering Laboratory, and how it has been exploited within the Flight Dynamics Division with GSFC Code 500. Examples of specific improvement in the software itself and its processes are presented to illustrate the effectiveness of the methodology. Finally, the initial findings are given when this methodology was applied across the

  2. A proven knowledge-based approach to prioritizing process information

    NASA Technical Reports Server (NTRS)

    Corsberg, Daniel R.

    1991-01-01

    Many space-related processes are highly complex systems subject to sudden, major transients. In any complex process control system, a critical aspect is rapid analysis of the changing process information. During a disturbance, this task can overwhelm humans as well as computers. Humans deal with this by applying heuristics in determining significant information. A simple, knowledge-based approach to prioritizing information is described. The approach models those heuristics that humans would use in similar circumstances. The approach described has received two patents and was implemented in the Alarm Filtering System (AFS) at the Idaho National Engineering Laboratory (INEL). AFS was first developed for application in a nuclear reactor control room. It has since been used in chemical processing applications, where it has had a significant impact on control room environments. The approach uses knowledge-based heuristics to analyze data from process instrumentation and respond to that data according to knowledge encapsulated in objects and rules. While AFS cannot perform the complete diagnosis and control task, it has proven to be extremely effective at filtering and prioritizing information. AFS was used for over two years as a first level of analysis for human diagnosticians. Given the approach's proven track record in a wide variety of practical applications, it should be useful in both ground- and space-based systems.

  3. Capturing Provenance, Evolution and Modification of Clinical Protocols via a Heterogeneous, Semantic Social Network.

    PubMed

    Portokallidis, Nick; Drosatos, George; Kaldoudi, Eleni

    2016-01-01

    Healthcare delivery is largely based on medical best practices as in clinical protocols. Research so far has addressed the computerized execution of clinical protocols by developing a number of related representation languages, execution engines and integrated platforms to support real time execution. However, much less effort has been put into organizing clinical protocols for use and reuse. In this paper we propose a heterogeneous semantic social network to describe and organize clinical protocols based on their provenance, evolution and modifications. The proposed approach allows semantic tagging and enrichment of clinical protocols so that they can be used and re-used across platforms and also be linked directly to other relevant scientific information, e.g. published works in PubMed or personal health records, and other clinical information systems. PMID:27332270

  4. Spectral data analysis approaches for improved provenance classification

    NASA Astrophysics Data System (ADS)

    Sorauf, Kellen J.; Bauer, Amy J. R.; Miziolek, Andrzej W.; De Lucia, Frank C.

    2015-06-01

    In the last 10 years various chemometric methods have been developed and used for the analysis of spectra generated by Laser Induced Breakdown Spectroscopy (LIBS). One of the more successful and proven methods is Partial Least Squares Discriminant Analysis (PLS-DA). Recently PLS-DA was utilized for purposes of provenance of spent brass cartridges and achieved correct classification at around 93% with a false alarm rate of around 5%. The LIBS spectra from the cartridge samples are rich in emission lines from numerous mostly metallic elements comprising the brass and the cited results were based on the analysis of the full broadband high resolution spectra. It was observed that some of the lines were clearly saturated in all spectra, while others were sometimes saturated due to pulse-to-pulse variation. The pulse-to-pulse variation was also evident in the intensity variations of the spectra within cartridges and between cartridges. In order to improve on the accuracy of the classification we have developed some preprocessing strategies including the removal of spectral wavelength ranges susceptible to saturation and normalization techniques to diminish the effects of intensity variations in the spectra. The results indicate incremental improvements when applying additional preprocessing steps to the limit of 100% True Positives and 0% False Positives when utilizing selected wavelengths that are normalized and averaged.

  5. Influence of Rock Strength on Landscape Evolution and Sediment Provenance Records

    NASA Astrophysics Data System (ADS)

    Forte, A. M.; Whipple, K. X.; Yanites, B.

    2014-12-01

    Detrital minerals within the stratigraphic record provide key constraints for a range of geologic problems, including the first order tectonic setting of basins, structural histories within orogens, changes in climate, and major drainage network reorganizations. Numerous provenance techniques exist for linking detrital minerals to their source areas, but the majority of these methods share an underlying assumption that sediment delivered to a basin is a representative sample of the bedrock geology of the source area. Satisfying this assumption requires that sediment production rates, i.e. erosion rates, of a source area are uniform throughout. In detail, erosion rates within a source area vary as a function of patterns of landscape evolution dictated by rock erodibility, climate, and relative uplift rate, thus long-term and transient biasing of sediment provenance records is expected. Biases associated with landscape evolution in response to changes in climate, tectonics, or strength of exposed rock can last 10s Myr. Previous work recognized a potential influence of differential erosion on provenance records, but the relative importance of this effect has proven difficult to quantify with field data. To address this, we are using a modified version of the CHILD landscape evolution model (LEM), which supports numerous lithologies with different erodibilities within a landscape. We perform a sensitivity analysis on the relative influence of rock strength and changes in climate or uplift rate on provenance records. We focus on U-Pb detrital zircon records because these data have seen wide adoption as a provenance tool and the refractory nature of zircon makes them less likely to be influenced by chemical weathering effects that are beyond the scope of this work. We plan to test several scenarios including variations in rock erodibility and temporal changes in climate or uplift rate. We will then use results from the LEM to calculate erosion rates from different

  6. Rapid evolution and range expansion of an invasive plant are driven by provenance-environment interactions.

    PubMed

    Zenni, Rafael D; Bailey, Joseph K; Simberloff, Daniel

    2014-06-01

    To improve our ability to prevent and manage biological invasions, we must understand their ecological and evolutionary drivers. We are often able to explain invasions after they happen, but our predictive ability is limited. Here, we show that range expansions of introduced Pinus taeda result from an interaction between genetic provenance and climate and that temperature and precipitation clines predict the invasive performance of particular provenances. Furthermore, we show that genotypes can occupy climate niche spaces different from those observed in their native ranges and, at least in our case, that admixture is not a main driver of invasion. Genotypes respond to climate in distinct ways, and these interactions affect the ability of populations to expand their ranges. While rapid evolution in introduced ranges is a mechanism at later stages of the invasion process, the introduction of adapted genotypes is a key driver of naturalisation of populations of introduced species. PMID:24703489

  7. Multiobjective Optimization Using a Pareto Differential Evolution Approach

    NASA Technical Reports Server (NTRS)

    Madavan, Nateri K.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Differential Evolution is a simple, fast, and robust evolutionary algorithm that has proven effective in determining the global optimum for several difficult single-objective optimization problems. In this paper, the Differential Evolution algorithm is extended to multiobjective optimization problems by using a Pareto-based approach. The algorithm performs well when applied to several test optimization problems from the literature.

  8. A convergent diffusion and social marketing approach for disseminating proven approaches to physical activity promotion.

    PubMed

    Dearing, James W; Maibach, Edward W; Buller, David B

    2006-10-01

    Approaches from diffusion of innovations and social marketing are used here to propose efficient means to promote and enhance the dissemination of evidence-based physical activity programs. While both approaches have traditionally been conceptualized as top-down, center-to-periphery, centralized efforts at social change, their operational methods have usually differed. The operational methods of diffusion theory have a strong relational emphasis, while the operational methods of social marketing have a strong transactional emphasis. Here, we argue for a convergence of diffusion of innovation and social marketing principles to stimulate the efficient dissemination of proven-effective programs. In general terms, we are encouraging a focus on societal sectors as a logical and efficient means for enhancing the impact of dissemination efforts. This requires an understanding of complex organizations and the functional roles played by different individuals in such organizations. In specific terms, ten principles are provided for working effectively within societal sectors and enhancing user involvement in the processes of adoption and implementation. PMID:16979466

  9. Provenance record of Paleogene exhumation and Laramide basin evolution along the southern Rocky Mountain front

    NASA Astrophysics Data System (ADS)

    Bush, M. A.; Horton, B. K.; Murphy, M. A.; Stockli, D. F.

    2015-12-01

    The Sangre de Cristo and Nacimiento uplifts of the southern Rocky Mountains formed key parts of a major Paleogene topographic boundary separating the Cordilleran orogenic system from the North American plate interior. This barrier largely isolated interior Laramide basins from a broad Laramide foreland with fluvial systems draining to the Gulf of Mexico, and thereby played a critical role in the evolution of continental-scale paleodrainage patterns. New detrital zircon U-Pb geochronology and heavy mineral provenance analyses of Cretaceous-Paleogene siliciclastic strata in the Raton, Galisteo-El Rito, and San Juan basins record the partitioning of the broad Cordilleran (Sevier) foreland basin by Laramide basement uplifts. These trends are recognized both in provenance signals and depositional styles corresponding to cratonward (eastward) propagation of the Laramide deformation front and resultant advance of flexural depocenters in the North American interior. Along the eastern flank of the deformation front, the Raton basin shows a mix of Cordilleran, Appalachian, and Grenville age zircons restricted to the Cretaceous Dakota and Vermejo formations, marine units of the Western Interior Seaway. Upsection, the Cordilleran age peaks are absent from Paleocene-Eocene units, consistent with significant Laramide drainage reorganization and isolation from Cordilleran sources to the west. In the Galisteo-El Rito basin system, a shift to dominantly Mazatzal-Yavapai basement ages is recognized in the Paleocene El Rito and Oligocene Ritito formations. The heavy mineral results show a corresponding shift to less mature, dominantly metamorphic source compositions. These new datasets bear upon Cretaceous-Cenozoic reconstructions of North American paleodrainage and have implications for potential linkages between major fluvial systems of the southern Rocky Mountains and Paleogene deepwater reservoir units in the Gulf of Mexico basin.

  10. Bridging the Gap between Scientific Data Producers and Consumers: A Provenance Approach

    SciTech Connect

    Stephan, Eric G.; Pinheiro da Silva, Paulo; Kleese van Dam, Kerstin

    2013-06-03

    Despite the methodical and painstaking efforts made by scientists to record their scientific findings and protocols, a knowledge gap problem continues to persist today between producers of scientific results and consumers because technology is performing the exchange of data as opposed to scientists making direct contact. Provenance is a means to formalize how this knowledge is transferred. However, for it to be meaningful to scientists, the provenance research community needs continued contributions from the scientific community to extend and leverage provenance-based vocabularies and technology from the provenance community. Going forward the provenance community must also be vigilant to meet scalability needs of data intensive science

  11. Simple approach to sediment provenance tracing using element analysis and fundamental principles

    NASA Astrophysics Data System (ADS)

    Matys Grygar, Tomas; Elznicova, Jitka; Popelka, Jan

    2016-04-01

    Common sediment fingerprinting techniques use either (1) extensive analytical datasets, sometimes nearly complete with respect to accessible characterization techniques; they are processed by multidimensional statistics based on certain statistical assumptions on distribution functions of analytical results and conservativeness/additivity of some components, or (2) analytically demanding characteristics such as isotope ratios assumed to be unequivocal "labels" on the parent material unaltered by any catchment process. The inherent problem of the approach ad (1) is that interpretation of statistical components ("sources") is done ex post and remains purely formal. The problem of the approach ad (2) is that catchment processes (weathering, transport, deposition) can modify most geochemical parameters of soils and sediments, in other words, that the idea that some geochemistry parameters are "conservative" may be idealistic. Grain-size effects and sediment provenance have a joint influence on chemical composition of fluvial sediments that is indeed not easy to distinguish. Attempts to separate those two main components using only statistics seem risky and equivocal, because grain-size dependence of element composition is nearly individual for each element and reflects sediment maturity and catchment-specific formation transport processes. We suppose that the use of less extensive datasets of analytical results and their interpretation respecting fundamental principles should be more robust than only statistic tools applied to overwhelming datasets. We examined sediment composition, both published by other researchers and gathered by us, and we found some general principles, which are in our opinion relevant for fingerprinting: (1) Concentrations of all elements are grain-size sensitive, i.e. there are no "conservative" elements in conventional sense of provenance- or transport-pathways tracing, (2) fractionation by catchment processes and fluvial transport changes

  12. An agent-based approach for capturing and linking provenance in geoscience workflows

    NASA Astrophysics Data System (ADS)

    Narock, Tom; Yoon, Victoria

    2015-06-01

    Provenance is becoming increasingly important as web services and computational workflows enable new methods by which work is conducted. Yet, there exist sets of questions that cannot be addressed by current provenance capture systems. We address these challenges by leveraging a service provenance ontology that captures execution details of workflow constituent web services. The ontology is used in conjunction with a multi-agent system to automate provenance aggregation and collation. The use of a multi-agent system eliminates the need to modify service interfaces, as was done in previous research. Simulation experiments are used to evaluate multiple agent topologies and identify an efficient and scalable system that scales to large numbers of workflows.

  13. Student Teachers' Approaches to Teaching Biological Evolution

    NASA Astrophysics Data System (ADS)

    Borgerding, Lisa A.; Klein, Vanessa A.; Ghosh, Rajlakshmi; Eibel, Albert

    2015-06-01

    Evolution is fundamental to biology and scientific literacy, but teaching high school evolution is often difficult. Evolution teachers face several challenges including limited content knowledge, personal conflicts with evolution, expectations of resistance, concerns about students' conflicts with religion, and curricular constraints. Evolution teaching can be particularly challenging for student teachers who are just beginning to gain pedagogical knowledge and pedagogical content knowledge related to evolution teaching and who seek approval from university supervisors and cooperating teachers. Science teacher educators need to know how to best support student teachers as they broach the sometimes daunting task of teaching evolution within student teaching placements. This multiple case study report documents how three student teachers approached evolution instruction and what influenced their approaches. Data sources included student teacher interviews, field note observations for 4-5 days of evolution instruction, and evolution instructional artifacts. Data were analyzed using grounded theory approaches to develop individual cases and a cross-case analysis. Seven influences (state exams and standards, cooperating teacher, ideas about teaching and learning, concerns about evolution controversy, personal commitment to evolution, knowledge and preparation for teaching evolution, and own evolution learning experiences) were identified and compared across cases. Implications for science teacher preparation and future research are provided.

  14. U-Pb Detrital Zircon Ages from Sarawak: Changes in Provenance Reflecting the Tectonic Evolution of Southeast Asia

    NASA Astrophysics Data System (ADS)

    Breitfeld, H. T.; Galin, T.; Hall, R.

    2014-12-01

    Sarawak is located on the northern edge of Sundaland in NW Borneo. Five sedimentary basins are distinguished with ages from Triassic to Cenozoic. New light mineral, heavy mineral and U-Pb detrital zircon ages show differences in provenance reflecting the tectonic evolution of the region. The oldest clastic sediments are Triassic of the Sadong-Kuching Basin and were sourced by a Carnian to Norian volcanic arc and erosion of Cathaysian rocks containing zircons of Paleoproterozoic age. Sandstones of the Upper Jurassic to Cretaceous Bau-Pedawan Basin have distinctive zircon populations indicating a major change of tectonic setting, including initiation of subduction below present-day West Sarawak in the Late Jurassic. A wide range of inherited zircon ages indicates various Cathaysian fragments as major source areas and the arrival of the SW Borneo Block following subduction beneath the Schwaner Mountains in the early Late Cretaceous. After collision of the SW Borneo Block and the microcontinental fragments with Sundaland in the early Late Cretaceous, deep marine sedimentation (Pedawan Formation) ceased, and there was uplift forming the regional Pedawan-Kayan unconformity. Two episodes of extension were responsible for basin development on land from the latest Cretaceous onwards, probably in a strike-slip setting. The first episode formed the Kayan Basin in the Latest Cretaceous (Maastrichtian) to Early Paleocene, and the second formed the Ketungau Basin and the Penrissen Sandstone in the Middle to Late Eocene. Zircons indicate nearby volcanic activity throughout the Early Cenozoic in NW Borneo. Inherited zircon ages indicate an alternation between Borneo and Tin Belt source rocks. A large deep marine basin, the Rajang Basin, formed north of the Lupar Line fault. Zircons from sediments of the Rajang Basin indicate they are of similar age and provenance as the contemporaneous terrestrial sediments to the south suggesting a narrow steep continental Sundaland margin at the

  15. A Multi-technique Approach for Provenance Studies of Mesozoic Clastic Rocks in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Matthews, N. E.; Zimmermann, U.; Støle, L.; Ruud, C.; Mostafa, E.; Andò, S.; Borromeo, L.; Magnaghi, M.; Lapen, T. J.

    2015-12-01

    Sediments of Mesozoic age deposited in the Arctic Hammerfest and Tromsø basins (southern Barents Sea) are the focus of a comprehensive provenance study which forms part of ongoing work by the LoCrA consortium (Lower Cretaceous Basin Studies in the Arctic). Jurassic (Stø, Fuglen, Hekkingen) and Cretaceous (Knurr, Kolje, Kolmule) formations were sampled from seven wells. Analytical methods include petrography, whole-rock geochemistry, heavy mineral (HM) analysis and U-Pb on detrital zircons. HM concentration is <1%, with an ultrastable HM assemblage of zircon, rutile, tourmaline, spinel, apatite, garnet, chloritoid and common authigenic heavy minerals and opaques. Cretaceous sedimentary rocks show geochemical variations that reflect an unrecycled Upper Continental Crust signature, whereas Jurassic detritus tends to show more evidence of recycling with a relatively low input of mafic material. Kolmule Formation whole-rock geochemistry indicates sediment recycling from a major Sc-depleted but intermediate to mafic source and hence suggests input of rift detritus from the syn-depositional opening of the Atlantic Ocean. U-Pb ages for detrital zircons for Cretaceous sandstones show age groups of 200-500 Ma, 1200-1800 Ma, and 2100-2800 Ma, indicating potential source regions in the Urals/Novaya Zemlya, the Caledonides, Grenvillian/Sveconorwegian, and Palaeoproterozoic and Archean sources. Provenance data via geochemistry and HM analysis indicate different sources in the same formation basin-wide, with a significant change in provenance and sediment composition from Jurassic to Cretaceous and between the Knurr and Kolmule formations. These differences in composition need to be compared to detailed single grain studies and may only be explained in terms of basin dynamics, or even on a smaller scale, in terms of facies distributions. If so, this case study raises concerns about the use of single samples for provenance models on a larger scale.

  16. Detrital zircon provenance analysis of the Great Valley Group, California: Evolution of an arc-forearc system

    USGS Publications Warehouse

    DeGraaff-Surpless, K.; Graham, S.A.; Wooden, J.L.; McWilliams, M.O.

    2002-01-01

    The improved resolution of sediment provenance from detrital zircon analysis of Great Valley stratigraphy enables recognition of previously undocumented arc magmatism and the evolution of regional drainage systems within the Cretaceous arc-forearc system related to uplift, magmatism, and structure in the arc. Great Valley detrital zircon age data confirm previous studies that indicate that the locus of the sediment source in the southern Sierra Nevada arc migrated east with the active volcanic front and suggest rapid rates of uplift and unroofing of the southern arc. Sacramento Valley detrital zircon age data indicate a more complex history of drainage in the northern Klamath-Sierran arc than previously documented. Detrital zircon age distributions from the Cache Creek section of the Great Valley Group broaden through time from nearly unimodal age distributions to signatures with multiple age peaks. This transition to more broadly distributed detrital zircon age spectra likely results from a combination of (1) expanding subaerial drainage systems from highly localized to more broadly distributed catchments; (2) changing shelf and submarine-canyon morphology with rising sea level and/or basin subsidence; (3) increased degree of dissection of the Klamath-Sierran arc; and (4) potential drainage capture and redirection within the arc. Sacramento Valley detrital zircon age data also record a pulse of Late Jurassic to Early Cretaceous magmatism in the northwestern Sierra Nevada arc, an age of Cordilleran magmatism and deformation represented by limited exposure in the modern Sierra Nevada. These results offer significant new insights into the evolution of a well-studied arc-forearc system.

  17. An Approach to Evaluate Scientist Support in Abstract Workflows and Provenance Traces

    SciTech Connect

    Salayandia, Leonardo; Gates, Ann Q.; Pinheiro da Silva, Paulo

    2012-11-02

    Abstract workflows are useful to bridge the gap between scientists and technologists towards using computer systems to carry out scientific processes. Provenance traces provide evidence required to validate results and support their reuse. Assuming both technologies are based on formal semantics, a knowledge-based system that consistently merges both technologies is useful for scientists that produce data to document their data collecting and transformation processes; it is also useful for scientists that reuse data to assess scientific processes and resulting datasets produced by others. While evaluation of each technology is necessary for a given application, this work discusses their combined evaluation. The claim is that both technologies should complement each other and align consistently to a scientist’s perspective in order to be effective for science. Evaluation criteria are proposed based on lessons learned and exemplified for discussion.

  18. Provenance analysis of the Oligocene turbidites (Andaman Flysch), South Andaman Island: A geochemical approach

    NASA Astrophysics Data System (ADS)

    Bandopadhyay, P. C.; Ghosh, Biswajit

    2015-07-01

    The Oligocene-aged sandstone-shale turbidites of the Andaman Flysch are best exposed along the east coast of the South Andaman Island. Previously undocumented sandstone-shale geochemistry, investigated here, provides important geochemical constraints on turbidite provenance. The average 70.75 wt% SiO2, 14.52 wt% Al2O3, 8.2 wt% FeMgO and average 0.20 Al2O3/SiO2 and 1.08 K2O/Na2O ratios in sandstones, compare with quartzwackes. The shale samples have average 59.63 wt% SiO2, 20.29 wt% Al2O3, 12.63 wt% FeMgO and average 2.42 K2O/Na2O and 0.34 Al2O3/SiO2 ratios. Geochemical data on CaO-Na2O-K2O diagram fall close to a granite field and on K2O/Na2O-SiO2 diagram within an active continental margin tectonic setting. The range and average values of Rb and Rb/Sr ratios are consistent with acid-intermediate igneous source rocks, while the values and ratios for Cr and Ni are with mafic rocks. Combined geochemical, petrographic and palaeocurrent data indicate a dominantly plutonic-metamorphic provenance with a lesser contribution from sedimentary and volcanic source, which is possibly the Shan-Thai continental block and volcanic arc of the north-eastern and eastern Myanmar. Chemical index of alteration (CIA) values suggests a moderate range of weathering of a moderate relief terrane under warm and humid climate.

  19. Structural and drainage pattern evolution of the Alborz Mountains (N Iran) inferred from provenance data and magnetostratigraphy

    NASA Astrophysics Data System (ADS)

    Ballato, P.; Landgraf, A.; Strecker, M. R.; Friedrich, A.; Tabatabaei, S.

    2007-12-01

    The Alborz Mts, N Iran, constitute an active, E-W-oriented, double verging orogen, within the continental collision zone between Arabia and Eurasia. GPS data show that currently convergence is partitioned in the Alborz by 6 mmyr-1 of NNE directed shortening and 4 mmyr-1 of left-lateral motion. The growth of the Alborz was associated with the development of adjacent foreland basins. Here, we discuss the evolution of the southern Alborz and its foreland basin. We present a sandstone and conglomerate provenance study, combined with sedimentary facies analysis, and magnetostratigraphy of a 7200-m-thick sedimentary section in the foreland basin, previously thought to be Mio- Pleistocene in age. This section includes three first-order coarsening and thickening upward units and documents a gradual transition from restricted marine to lacustrine, braided river (U1 and U2), and alluvial fan depositional environments (U3). These units were deposited between 17.5 and 7.8 Ma. Assuming a constant accumulation rate for the alluvial-fan conglomerates of U3, the top of the section is approximately 6 m.y. old. The derived accumulation rates correlate with the cyclicity of the recognized units: at the bottom of each cycle in association with the fine-grained facies, the accumulation rates are faster, while with the appearance of coarse- grained facies the accumulation rates decrease. Fifty sandstone samples were analyzed using the Gazzi-Dickinson sandstone provenance method. The detrital modes of lithic grains indicate at least two first-order variations in the source area. The first major change occurred at the bottom of U1 and is characterised by an increase of low-grade metamorphic clasts and a concomitant decrease in volcanoclastic grains. The second major change is manifested at the base of U3 with a progressive decrease in low-grade metamorphic clasts and the increase of carbonates and volcanic lithics. The analysis of conglomerate clasts shows a relatively uniform composition

  20. Geochemical evolution of the Tertiary succession of the NW shelf, Bengal basin, Bangladesh: Implications for provenance, paleoweathering and Himalayan erosion

    NASA Astrophysics Data System (ADS)

    Roy, Dhiman Kumer; Roser, B. P.

    2013-12-01

    Whole rock major, trace and rare earth element (REE) compositions of Paleogene to Neogene sedimentary rocks of the NW shelf succession (Province 1) of Bangladesh contain a record of interaction of the India and Asian plates, Himalayan tectonism, and climatic development. Analyses of 66 sandstones and mudrocks from the Tertiary succession of Bangladesh were made to examine provenance, source weathering, and the influence of paleoclimate and tectonism. The sediments display linear geochemical trends due to quartz dilution, and varying quartz-clay ratios produced by hydrodynamic sorting. Chondrite-normalized REE patterns for both sandstones and mudrocks from different groups are similar to upper continental crust, with moderate to high LREE enrichment (lithotypes within formations average LaN/YbN 5.31-11.41) and marked negative Eu anomalies (Eu/Eu* 0.51-0.69). Based on geochemical criteria the succession can be divided into three parts (Jaintia; Barail-Surma; and Dupi Tila). Very high silica contents in Jaintia Tura sandstones and high Chemical Index of Alteration (CIA) indices in Kopili mudrocks (Fe-shales) suggest derivation from a deeply weathered and stable cratonic source (India). The Tura sandstones are interpreted as first-cycle quartz arenites, produced while the Indian plate drifted across equatorial regions during the Paleocene-Eocene Thermal maximum (PETM). The Barail-Surma and Dupi Tila sediments were derived from a felsic orogen (the Himalaya). The Barail-Surma sediments were mainly derived from the Trans Himalayan Batholith and associated granitoids, with significant contribution from the Lesser Himalaya. Mafic input is also evident, probably from intraoceanic arc material within the Himalaya. Barail mudrocks have uniformly high CIA values (92-95), suggesting intense steady-state weathering of their proto-Himalayan source, and warm and humid climate. In contrast, CIA values of Surma mudrocks range from 66 to 93 (average 84), suggesting non-steady state

  1. Provenance evolution of the Western foreland basin and its relationship to the exhumation of source rocks during arc-continent collision

    NASA Astrophysics Data System (ADS)

    Nagel, S.; Fellin, M. G.; Castelltort, S.; Willett, S. D.; Mouthereau, F.; Lin, A. T.

    2012-04-01

    Late Miocene to Pleistocene sedimentary rocks in the Western foreland basin of Taiwan record the evolution of an orogenic wedge during oblique arc-continent collision between the Luzon volcanic arc and the Chinese passive margin. Our stratigraphic record reaches back to pre-collisional sediments of the Late Miocene to Pliocene, which were deposited on the Chinese passive margin. A dramatic change is observed in the Pliocene, as the depositional center shifts to a collisional basin developing on the passive margin due to the obliquely colliding Luzon Arc and input of sediment from the approaching accretionary wedge. Synorogenic sedimentation continues into the Pleistocene providing a history of material being eroded from the growing mountains to the east. We apply standard provenance analysis techniques on several stratigraphic profiles along the strike of the orogen to relate the sediments to their source and reconstruct possible distribution pathways to further enhance a paleogeographic reconstruction of the area. Unmetamorphosed mudstones within our sedimentary record contain abundant detrital illite, chlorite and zircons. The Illite Crystallinity Index (IC) and the fission-track dating of detrital zircons provides robust information about the thermal history of source terrains, and we combine these methods to infer the timing of exhumation of metamorphic rocks in the Central Range of Taiwan. The initial input of illite minerals with high crystallinity and of zircons with reset ages (younger than 10 Ma) is recorded in the Yutengping fm. and Chinsui Shale, around 3.5 Ma in the north and around 2.5 Ma in the South, contemporaneously with a deepening and widening of the depositional basin. This is the time of deposition of the mud-dominated Chinshui shale, interpreted as the "underfilled" stage of the foreland basin. This clearly marks accelerated subsidence caused by the approach of the growing orogen. In the south, the illite crystallinity and the frequency of

  2. Middle-Late Mesozoic sedimentary provenances of the Luxi and Jiaolai areas: Implications for tectonic evolution of the North China Block

    NASA Astrophysics Data System (ADS)

    Xu, Jianqiang; Li, Zhong

    2015-11-01

    Provenances of sedimentary rocks may provide important constraints on the tectonic evolution of the North China Block (NCB). Previous studies have demonstrated that the northern NCB (NNCB) and the Xing-Meng orogenic belt (XMOB) supplied massive detritus southward into the hinterland of the NCB during the Jurassic. In order to study the evolution of sedimentary provenance during the Middle-Late Mesozoic, U-Pb geochronology and Hf isotopic geochemistry of detrital zircon grains and chemical compositions of detrital garnets from sandstones in the Luxi and Jiaolai areas, eastern NCB, were analyzed in combination with published data on the Jurassic sandstones. The Late Paleozoic-Mesozoic (367-139 Ma) zircons in the lowermost Cretaceous Mengyin Formation samples from the Luxi area show εHf(t) values of -15.3 to -3.2 and +1.3 to +10.0, which are very similar to the results of analyses of the Jurassic formations. Further, the increased amount of Mesozoic zircons and granulite-derived garnets in the Mengyin Formation samples, compared to those in the Jurassic samples, indicates there was more detritus supply from the NNCB than from the XMOB. In the overlying Qingshan Formation samples, zircon grains do not exhibit Paleozoic ages, but most of them have Early Cretaceous ages and negative εHf(t) values, which are similar to the zircon grains extracted from the widespread Early Cretaceous igneous rocks in the NCB. This suggests that the provenance might have changed to a locally derived source. In contrast, the zircon population of the Early Cretaceous sandstones from the Jiaolai basin is dominated by grains of mid-Neoproterozoic age (700-900 Ma) which signifies contribution from the Sulu orogen. Moreover, the detrital garnet assemblages of sandstones in the Luxi area are not consistent with those from representative metamorphic rocks in the Sulu orogen. The above results seem to confirm that the Mesozoic sedimentary provenance of the Luxi area had no evident connection with

  3. Insights from heavy minerals and zircon U-Pb ages into the middle Miocene-Pliocene provenance evolution of the Yinggehai Basin, northwestern South China Sea

    NASA Astrophysics Data System (ADS)

    Jiang, Tao; Cao, Licheng; Xie, Xinong; Wang, Zhenfeng; Li, Xushen; Zhang, Yingzhao; Zhang, Daojun; Sun, Hui

    2015-08-01

    The well-preserved Cenozoic sedimentary record in the Yinggehai Basin, South China Sea, is suitable to explore the tectonic and climatic evolution of SE Asia. Red River, a large-scale fluvial system in this region, was previously regarded as the major sediment source for the basin. Here we combine heavy mineral analysis and detrital zircon U-Pb dating to shed new light on the middle Miocene-Pliocene provenance evolution at a basin scale. The results clearly reveal potential source areas additional to the Red River. Sediments have been delivered to the proximal areas from Hainan Island, as indicated by the high zircon content and the Yanshanian U-Pb ages in the southern segment of the Yingdong Slope. A provenance from Central Vietnam is explicitly discerned in the upper Miocene of the Central Depression, where sediments are characterized by few metamorphic heavy minerals and the U-Pb age pattern peaking at around 250 Ma and 440 Ma. Coeval large-scale relative sea-level fall and rapid exhumation along the Vietnamese margin together may have facilitated this long-distance sediment transport. Provenance of sediments from the Red River seems to change over time. Song Lo River, on the north side of the main stream, probably flowed from the NE and carried Neoproterozoic-early Paleozoic zircons to the Yinggehai Basin during the middle Miocene. Since the late Miocene, rocks along the Red River Fault Zone have become the dominant source. Subsequently, widespread metamorphic minerals in the Central Depression of the Yinggehai Basin, combined with the strong river incision and high offshore sedimentation rates, indicate an increased sediment supply from the Red River in the Pliocene.

  4. Sedimentological and stratigraphic evolution of the southern part of the Barberton greenstone belt: A case of changing provenance and stability

    NASA Technical Reports Server (NTRS)

    Lowe, D. R.; Byerly, G. R.

    1986-01-01

    The sedimentological and stratigraphic evolution of the 3.5 to 3.3 Ga Barberton Greenstone Belt can be divided into three principal stages: (1) the volcanic platform stage during which at least 8 km of mafic and ultramafic volcanic rocks, minor felsic volcanic units, and thin sedimentary layers (Onverwacht Group) accumulated under generally anorogenic conditions; (2) a transitional stage of developing instability during which widespread dacitic volcanism and associated pyroclastic and volcaniclastic sedimentation was punctuated by the deposition of terrigenous debris derived by uplift and shallow erosion of the belt itself (Fig Tree Group); (3) an orogenic stage involving cessation of active volcanism, extensive thrust faulting, and widespread deposition of clastic sediments representing deep erosion of the greenstone belt sequence as well as sources outside of the belt (Moodies Group).

  5. Combined heavy mineral and biomarker analysis in silt: a novel approach for provenance studies (Indus Fan, IODP Expedition 355)

    NASA Astrophysics Data System (ADS)

    Andò, Sergio; Bratenkov, Sophia; Hahn, Annette; George, Simon; Clift, Peter D.; Garzanti, Eduardo

    2016-04-01

    A high-resolution mineralogical study of Indus Fan turbiditic sediments cored during IODP Expedition 355 (Arabian Sea Monsoon) in the Laxmi Basin was carried out to investigate and quantify the different compositional signatures encoded in the sand, silt, and clay fractions. The turbidite deposits recovered at IODP Sites U1456 and U1457 in sedimentological Unit II were chosen as the best candidate for such a study. The integrated dataset presented here was obtained by coupling traditional and innovative bulk-sediment to single-grain analytical techniques, including bulk petrography, heavy-mineral and biomarker analyses on the same samples. Reliable quantitative results even in the medium to fine silt classes, which represent the dominant sediment sizes encountered in the recovered cores, were obtained by point-counting under the microscope, assisted by Micro-Raman spectroscopy (Andò et al., 2011; 2014). Preliminary data from the studied turbidites document rich and diverse heavy mineral assemblages in both the sand and silty-sand fractions. Heavy-mineral concentrations, as well as the number of mineral species, reach a maximum in sand and tend to decrease with grain size, becoming minimal in the clay fraction. Conversely, the biomarker analysis is generally focused on the finer sediment fractions and clay, where better preservation of biomarker compounds are obtained. The two approaches are thus complementary. Because biomarkers tend to be depleted in sand and heavy minerals in clay, the medium silt fraction represents the most suitable size window for the joint application of these two techniques. Comparing heavy-mineral assemblages with biomarkers allows us to evaluate both continental and marine inputs in turbidites and the hemipelagic deposits of the Indus Fan. This new methodological approach plays a key role in the identification of the effects of climate change on marine depositional environments and helps us to differentiate among the diverse Himalayan

  6. Student Teachers' Approaches to Teaching Biological Evolution

    ERIC Educational Resources Information Center

    Borgerding, Lisa A.; Klein, Vanessa A.; Ghosh, Rajlakshmi; Eibel, Albert

    2015-01-01

    Evolution is fundamental to biology and scientific literacy, but teaching high school evolution is often difficult. Evolution teachers face several challenges including limited content knowledge, personal conflicts with evolution, expectations of resistance, concerns about students' conflicts with religion, and curricular constraints. Evolution…

  7. Provenance and tectonic-paleogeographic evolution: Constraints from detrital zircon U-Pb ages of Late Triassic-Early Jurassic deposits in the northern Sichuan basin, central China

    NASA Astrophysics Data System (ADS)

    Shao, Tongbin; Cheng, Nanfei; Song, Maoshuang

    2016-09-01

    U-Pb ages of 290 new detrital zircons from five Late Triassic-Early Jurassic sandstone samples in the northern Sichuan basin, along with other geological data, are used to constrain the sediment provenance and evaluate tectonic-paleogeographic evolution for the adjacent orogens through/from which these sediments were potentially derived. The Upper Triassic depocenter was located at the front of the Longmen Shan belt, and sediments in the western, southern and eastern Sichuan basin shared the southern North China block (NCB) and Qinling belt with the eastern Songpan-Ganzi terrane of Middle-Upper Triassic via the Longmen Shan belt, whereas the northern part of the basin was fed by dominant South Qinling belt (SQB) and northern Yangtze block and possibly subordinate southern NCB. Also, the youngest population in the northern Sichuan basin has a slightly younger age peak (∼235 Ma) than those (∼270 Ma) in other parts of the basin. During the Early Jurassic, the depocenter was still at the front of the Longmen Shan belt but only northern regions (e.g., SQB and northern Yangtze block) fed the basin. The northern Sichuan basin received less sediments from the southern NCB and more from the SQB and northern Yangtze block during the Early Jurassic than during the Late Triassic. The middle Mesoproterozoic detrital zircons, which likely originated from the North Qinling belt and northern Yangtze block where rocks with these zircons may be unexposed, occur more widely in the Lower Jurassic than in the Upper Triassic. These facts suggest that from the Late Triassic to Early Jurassic, it was increasingly difficult for sediments to transport from the NCB into the northern Sichuan basin and the provenance transferred progressively from the southern NCB to both the SQB and northern Yangtze block, implying the continuous South China block-NCB collision during that time.

  8. Clay mineral contribution from various provenances in the northern South China Sea over the past 400 kyr: implications for the East Asian monsoon evolution

    NASA Astrophysics Data System (ADS)

    Chen, Quan; Liu, Zhifei; Xie, Xin; Kissel, Catherine

    2014-05-01

    Clay mineralogy of Core MD12-3432 taken at 2125 m water depth (CIRCEA cruise on board the R.V. Marion Dufresne, IPEV) in the northern South China Sea was investigated in order to understand the time series contribution of terrigenous sediments from various provenances. With calibration of a low-resolution analysis on carbonate concentration and major elements, we converted the XRF core scanned calcium data into a high-resolution carbonate content records. Through referring to the well-dated carbonate record of nearby Core MD05-2904, we established a reliable age model, indicating about 400 kyr ago at the bottom of Core MD12-3432. The clay mineral assemblage is dominated by smectite (23-59%) and illite (22-43%), with minor chlorite (13-27%) and kaolinite (4-13%). The time series variation of clay mineral assemblages indicates strong glacial-interglacial cyclicity. In general, the variation in smectite content is similar to that of carbonate concentration, with higher values during interglacials than during glacials, while illite and chlorite contents showing opposite patterns. The change in kaolinite content shows an independent pattern with high values during glacials, corresponding well with the illite crystallinity variation. The provenance analysis of these clay minerals suggests three end-member sources: all smectites derive from Luzon, all kaolinites originate from the Pearl River, and illite and chlorite are coming from both the Pearl River and Taiwan. Using the linear separation method of illite crystallinity, a time series of the clay mineral contribution from the three major provenances to the northern South China Sea was reconstructed. Combined with spectral analyses, we suggest the clay mineral contribution from Pearl River was mainly influenced by sea level change, while the East Asian summer monsoon controlled the contribution from Luzon. The strong precipitation rate related to intensive East Asian summer monsoon would have enhanced the denudation and

  9. The QCD evolution of TMD in the covariant approach

    NASA Astrophysics Data System (ADS)

    Efremov, A. V.; Teryaev, O. V.; Zavada, P.

    2016-02-01

    The procedure for calculation of the QCD evolution of transverse momentum dependent distributions within the covariant approach is suggested. The standard collinear QCD evolution together with the requirements of relativistic invariance and rotational symmetry of the nucleon in its rest frame represent the basic ingredients of our approach. The obtained results are compared with the predictions of some other approaches.

  10. Systems approaches in understanding evolution and evolvability.

    PubMed

    Agarwal, Sumeet

    2013-12-01

    Systems and network-based approaches are becoming increasingly popular in cellular biology. One contribution of such approaches has been to shed some light on the evolutionary origins of core organisational principles in biological systems, such as modularity, robustness, and evolvability. Models of interactions between genes (epistasis) have also provided insight into how sexual reproduction may have evolved. Additionally, recent work on viewing evolution as a form of learning from the environment has indicated certain bounds on the complexity of the genetic circuits that can evolve within feasible quantities of time and resources. Here we review the key studies and results in these areas, and discuss possible connections between them. In particular, we speculate on the link between the two notions of 'evolvability': the evolvability of a system in terms of how agile it is in responding to novel goals or environments, and the evolvability of certain kinds of gene network functionality in terms of its computational complexity. Drawing on some recent work on the complexity of graph-theoretic problems on modular networks, we suggest that modularity as an organising principle may have its raison d'etre in its ability to enhance evolvability, in both its senses. PMID:24120732

  11. Provenance of unknown plutonium material.

    PubMed

    Nicolaou, G

    2008-10-01

    The determination of the provenance of 'unknown' plutonium material is demonstrated through a simulation study based on an isotopic fingerprinting approach. Plutonium of known provenance was considered as the 'unknown' nuclear material in order to evaluate the potential of the approach and verify its predictive capabilities. Factor analysis was used to compare the Pu isotopic composition of the 'unknown' material with Pu isotopic compositions simulating well known spent fuels from a range of commercial nuclear power stations. The provenance of the 'unknown material' is assigned to the commercial fuel with which exhibits the highest degree of similarity with respect to the Pu composition. The approach appears promising since it accurately predicted the provenance of the one 'unknown' sample considered; nevertheless, the approach is still at the development stage. Important challenging issues related to the simulation uncertainties and its testing on real laboratory samples have to be explored prior to evaluating the potential of the approach. PMID:18639370

  12. Silurian clastic sediments in the North Qilian Shan, NW China: Chemical and isotopic constraints on their forearc provenance with implications for the Paleozoic evolution of the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Yan, Z.; Xiao, W. J.; Windley, B. F.; Wang, Z. Q.; Li, J. L.

    2010-11-01

    The North Qilian Shan is an accretion-collision orogenic belt in the northeastern margin of the Tibetan Plateau that connects the North China plate to the north with the Tethyan orogenic assemblage to the south. Its Early Paleozoic temporal-spatial tectonic evolution has been extensively studied, but the nature and tectonic setting of its Silurian deposition is poorly understood. Our new petrological analysis suggests that the clast composition of fan conglomerates is complex. In the Danbanshan and Zhongdabanshan sections, abundant lenticular conglomerate beds contain mainly subrounded-rounded metamorphic clasts; whereas the Tongziba and Haichaoba sections contain volcanic, chert, limestone, ultramafic and granitoid clasts. However, in the Sunan area, clast types are relatively simple, dominated by basalt and granitoids, and at Tongziba gabbro and basalt clasts are subrounded and angular, indicating two different types of provenance. Ultramafic, limestone and abundant chert clasts in the Haichaoba and Tonghe conglomerates indicate an ophiolitic source, whereas subrounded-rounded quartzite and granitoid gneiss clasts were probably derived from the Central Qilian basement. Geochemical data from the volcanic and granitoid clasts suggest an arc-related source and their zircon U-Pb ages of 515-429 Ma suggest that the arc magmatism did not end in the Mid-Silurian. Sandstone petrology and detrital modes suggest that the Silurian sediments were deposited in a forearc basin. Paleogeographic reconstructions inferred from NNW-NNE paleocurrent data indicate that an island arc was present off the southern margin of the Silurian basin, and that southward subduction of oceanic crust between North China and the Qilian Shan was active or continued in the Silurian.

  13. Evolution as a Controversial Issue: A Review of Instructional Approaches

    ERIC Educational Resources Information Center

    Hermann, Ronald S.

    2008-01-01

    Although evolution has long been considered a controversial issue, little effort has been made to ensure that instructional approaches address the controversial nature of the issue. A framework for understanding the nature of controversy and some defining characteristics of controversial issues are provided. In light of this framework evolution is…

  14. A Proven Way to Incorporate Catholic Social Thought in Business School Curricula: Teaching Two Approaches to Management in the Classroom

    ERIC Educational Resources Information Center

    Dyck, Bruno

    2013-01-01

    Widespread agreement suggests that it is appropriate and desirable to develop and teach business theory and practice consistent with Catholic social teaching (CST) in Catholic business schools. Such a curriculum would cover the same mainstream material taught in other business schools, but then offer a CST approach to business that can be…

  15. The tectonic evolution of the Neoproterozoic Brasília Belt, central Brazil, based on SHRIMP and LA-ICPMS U-Pb sedimentary provenance data: A review

    NASA Astrophysics Data System (ADS)

    Pimentel, Márcio M.; Rodrigues, Joseneusa B.; DellaGiustina, Maria Emilia S.; Junges, Sergio; Matteini, Massimo; Armstrong, Richard

    2011-04-01

    The Brasília Belt is a Neoproterozoic orogenic belt in central Brazil, developed between the Amazon, São Francisco-Congo and Paranapanema cratons. It consists of a thick sedimentary pile, made up of several stratigraphic units, which have been deformed and metamorphosed along the western margin of the São Francisco Craton during the Brasiliano orogenic cycle. In the western part of the belt, a large, juvenile magmatic arc is exposed (the Goiás Magmatic Arc), consisting of calc-alkaline plutonic suites as well as volcano-sedimentary sequences, ranging in age between ca. 860 and 650 Ma. Regional-scale, west-dipping thrusts and reverse faults normally mark the limits between the main stratigraphic units, and clearly indicate tectonic transport towards the east. The age of deposition and tectonic significance of the sedimentary units comprising the Brasília Belt have been a matter of continuous debate over the last three decades. In the present paper, recent provenance data based on LA-ICPMS U-Pb ages of detrital zircon grains from several of these units, are reviewed and their significance for the age of deposition of the original sediments and tectonic evolution of the Brasília Belt are discussed. The Paranoá, Canastra and the Vazante groups, in the central part of the Belt, have detrital zircon grains with ages older than ca. 900 Ma and are interpreted as representative of the passive margin sequence deposited on the western margin of the São Francisco Craton. On the other hand, samples from the Araxá and Ibiá groups have a much younger population of Neoproterozoic zircon grains, as young as 650 Ma, and have been interpreted as syn-orogenic (fore-arc?) deposits. The Bambuí Group, exposed in the easternmost part of the belt and covering large areas of the São Francisco Craton also has young zircon grains and is interpreted, at least in part, as the foreland basin of the Brasília Belt.

  16. New approach to the differentiation of marble samples using thermal analysis and chemometrics in order to identify provenance

    PubMed Central

    2014-01-01

    Background The possibility of applying a novel chemometric approach which could allow the differentiation of marble samples, all from different quarries located in the Mediterranean basin and frequently used in ancient times for artistic purposes, was investigated. By suggesting tentative or allowing to rule out unlikely attributions, this kind of differentiation could, indeed, be of valuable support to restorers and other professionals in the field of cultural heritage. Experimental data were obtained only using thermal analytical techniques: Thermogravimetry (TG), Derivative Thermogravimetry (DTG) and Differential Thermal Analysis (DTA). Results The extraction of kinetic parameters from the curves obtained using these thermal analytical techniques allowed Activation Energy values to be evaluated together with the logarithm of the Arrhenius pre-exponential factor of the main TG-DTG process. The main data thus obtained after subsequent chemometric evaluation (using Principal Components Analysis) have already proved useful in the identification the original quarry of a small number of archaeological marble finds. Conclusion One of the most evident advantages of the thermoanalytical – chemometric approach adopted seems to be that it allows the certain identification of an unknown find composed of a marble known to be present among the reference samples considered, that is, contained in the reference file. On the other hand with equal certainty it prevents the occurrence of erroneous or highly uncertain identification if the find being tested does not belong to the reference file considered. PMID:24982691

  17. Articulating Babel: An approach to cultural evolution.

    PubMed

    Wimsatt, William C

    2013-12-01

    After an initial discussion of the character of interdisciplinary linkages between complex disciplines, I consider an area with confluences of many diverse disciplines-the study of cultural evolution. This must embrace not only the traditional biological sciences, but also the multiple often warring disciplines of the human sciences. This interdisciplinary articulation is in its early stages compared, e.g., to that of evolutionary biology or evolutionary developmental biology, and I try to lay out major axes along which its articulation should plausibly occur, given the relevant causal processes acting at different levels. One cannot have an adequate account of cultural evolution without recognizing a central role for cognitive and social development (since culture is cumulatively acquired by individuals through the life-cycle) and the social and cultural organizations and institutions and artifactual tools and infrastructure that support and structure these developmental processes. These induce a population structure that mediates the transmission, expression, and elaboration of culture, and in particular the different ways in which they scaffold learning and the development and articulation of complex skills. I consider how these elements should articulate the disciplines that tend to focus separately on them. Intentions and the market are not explicitly included in this account, and I consider ways in which these perspectives might enter. PMID:24189109

  18. Evolution of a Teaching Approach for Beginning Algebra

    ERIC Educational Resources Information Center

    Banerjee, Rakhi; Subramaniam, K.

    2012-01-01

    The article reports aspects of the evolution of a teaching approach over repeated trials for beginning symbolic algebra. The teaching approach emphasized the structural similarity between arithmetic and algebraic expressions and aimed at supporting students in making a transition from arithmetic to beginning algebra. The study was conducted with…

  19. Experimental approaches to studying cumulative cultural evolution

    PubMed Central

    Caldwell, Christine A.; Atkinson, Mark; Renner, Elizabeth

    2016-01-01

    In humans, cultural traditions often change in ways which increase efficiency and functionality. This process, widely referred to as cumulative cultural evolution, sees beneficial traits preferentially retained, and it is so pervasive that we may be inclined to take it for granted. However, directional change of this kind appears to distinguish human cultural traditions from behavioural traditions that have been documented in other animals. Cumulative culture is therefore attracting an increasing amount of attention within psychology, and researchers have begun to develop methods of studying this phenomenon under controlled conditions. These studies have now addressed a number of different questions, including which learning mechanisms may be implicated, and how the resulting behaviours may be influenced by factors such as population structure. The current article provides a synopsis of some of these studies, and highlights some of the unresolved issues in this field. PMID:27397972

  20. Differential Evolution approach to detect recent admixture

    PubMed Central

    2015-01-01

    The genetic structure of human populations is extraordinarily complex and of fundamental importance to studies of anthropology, evolution, and medicine. As increasingly many individuals are of mixed origin, there is an unmet need for tools that can infer multiple origins. Misclassification of such individuals can lead to incorrect and costly misinterpretations of genomic data, primarily in disease studies and drug trials. We present an advanced tool to infer ancestry that can identify the biogeographic origins of highly mixed individuals. reAdmix can incorporate individual's knowledge of ancestors (e.g. having some ancestors from Turkey or a Scottish grandmother). reAdmix is an online tool available at http://chcb.saban-chla.usc.edu/reAdmix/. PMID:26111206

  1. Gene-pseudogene evolution: a probabilistic approach

    PubMed Central

    2015-01-01

    Over the last decade, methods have been developed for the reconstruction of gene trees that take into account the species tree. Many of these methods have been based on the probabilistic duplication-loss model, which describes how a gene-tree evolves over a species-tree with respect to duplication and losses, as well as extension of this model, e.g., the DLRS (Duplication, Loss, Rate and Sequence evolution) model that also includes sequence evolution under relaxed molecular clock. A disjoint, almost as recent, and very important line of research has been focused on non protein-coding, but yet, functional DNA. For instance, DNA sequences being pseudogenes in the sense that they are not translated, may still be transcribed and the thereby produced RNA may be functional. We extend the DLRS model by including pseudogenization events and devise an MCMC framework for analyzing extended gene families consisting of genes and pseudogenes with respect to this model, i.e., reconstructing gene-trees and identifying pseudogenization events in the reconstructed gene-trees. By applying the MCMC framework to biologically realistic synthetic data, we show that gene-trees as well as pseudogenization points can be inferred well. We also apply our MCMC framework to extended gene families belonging to the Olfactory Receptor and Zinc Finger superfamilies. The analysis indicate that both these super families contains very old pseudogenes, perhaps so old that it is reasonable to suspect that some are functional. In our analysis, the sub families of the Olfactory Receptors contains only lineage specific pseudogenes, while the sub families of the Zinc Fingers contains pseudogene lineages common to several species. PMID:26449131

  2. Evolution, Physics, and Cancer: Disrupting Traditional Approache

    NASA Astrophysics Data System (ADS)

    Austin, Robert

    Physicists who were recruited to try and assist with the stubbornly constant mortality rates of cancer world-wide over the past 100 years have basically had the invitation withdrawn by the oncology community. The oncologists became annoyed with the independence of thought and the skepticism of some physicists with continuation of the present paradigm of the cancer genome as the rosette stone as the key to cancer. To quote a recent letter in Physics Today: ``Curing cancer is a complex biological problem to be solved by biologists''. Apparently our mission as minions is is to be high-level technicians. But I think that is wrong and will lead to continuation of the string of failures and deceptions foisted on the public at large by the Medical Industrial Complex, I think we really need to re-think cancer as a phenomena which is driven by evolution and may be desired by the organism and be a product of both the aging of the proteome and the genome. Further, searching for mutations (The Cancer Genome) may be completely the wrong direction, searching for protected genes may be as important as looking for mutated genes. I'll try to present the case that physicists should not have been kicked out of the Medical Industrial Complex that keeps the cancer business humming and profitable.

  3. Medical rare book provenance.

    PubMed Central

    Overmier, J A; Sentz, L

    1987-01-01

    Provenance is defined as the record of a book's ownership history. Its value and uses are explored. A survey of provenance practices in medical school rare book libraries found that only 21% of the reporting libraries maintain this important file. Examples of the uses and value of a provenance file in a medical rare book collection are presented. Decisions necessary to institute and maintain such a file are outlined and discussed. PMID:3828606

  4. An experimental approach to submarine canyon evolution

    NASA Astrophysics Data System (ADS)

    Lai, Steven Y. J.; Gerber, Thomas P.; Amblas, David

    2016-03-01

    We present results from a sandbox experiment designed to investigate how sediment gravity flows form and shape submarine canyons. In the experiment, unconfined saline gravity flows were released onto an inclined sand bed bounded on the downstream end by a movable floor that was used to increase relief during the experiment. In areas unaffected by the flows, we observed featureless, angle-of-repose submarine slopes formed by retrogressive breaching processes. In contrast, areas influenced by gravity flows cascading across the shelf break were deeply incised by submarine canyons with well-developed channel networks. Normalized canyon long profiles extracted from successive high-resolution digital elevation models collapse to a single profile when referenced to the migrating shelf-slope break, indicating self-similar growth in the relief defined by the canyon and intercanyon profiles. Although our experimental approach is simple, the resulting canyon morphology and behavior appear similar in several important respects to that observed in the field.

  5. Proven Weight Loss Methods

    MedlinePlus

    Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. It can lower ... at www.hormone.org/Spanish . Proven Weight Loss Methods Fact Sheet www.hormone.org

  6. Tectonomagmatic setting and provenance of the Santa Marta Schists, northern Colombia: Insights on the growth and approach of Cretaceous Caribbean oceanic terranes to the South American continent

    NASA Astrophysics Data System (ADS)

    Cardona, A.; Valencia, V.; Bustamante, C.; García-Casco, A.; Ojeda, G.; Ruiz, J.; Saldarriaga, M.; Weber, M.

    2010-10-01

    Metamorphosed volcano-sedimentary rocks accreted to the northern South American continental margin are major vestiges of the Caribbean oceanic plate evolution and its interactions with the continent. Selected whole rock geochemistry, Nd-Sr isotopes and detrital zircon geochronology were obtained in metabasic and metasedimentary rocks from the Santa Marta and San Lorenzo Schists in northernmost Colombia. Trace element patterns are characterized by primitive island arc and MORB signatures. Similarly initial 87Sr/ 86Sr-ɛ Nd isotopic relations correlate with oceanic arcs and MORB reservoirs, suggesting that the protoliths were formed within a back-arc setting or at the transition between the inta-oceanic arc and the Caribbean oceanic crust. Trace element trends from associated metasedimentary rocks show that the provenance was controlled by a volcanic arc and a sialic continental domain, whereas detrital U/Pb zircons from the Santa Marta Schists and adjacent southeastern metamorphic units show Late Cretaceous and older Mesozoic, Late Paleozoic and Mesoproterozoic sources. Comparison with continental inland basins suggests that this arc-basin is allocthonous to its current position, and was still active by ca. 82 Ma. The geological features are comparable to other arc remnants found in northeastern Colombia and the Netherland Antilles. The geochemical and U/Pb detrital signatures from the metasedimentary rocks suggest that this tectonic domain was already in proximity to the continental margin, in a configuration similar to the modern Antilles or the Kermadec arc in the Pacific. The older continental detritus were derived from the ongoing Andean uplift feeding the intra-oceanic tectonic environment. Cross-cutting relations with granitoids and metamorphic ages suggest that metamorphism was completed by ca. 65 Ma.

  7. Provenance in bioinformatics workflows

    PubMed Central

    2013-01-01

    In this work, we used the PROV-DM model to manage data provenance in workflows of genome projects. This provenance model allows the storage of details of one workflow execution, e.g., raw and produced data and computational tools, their versions and parameters. Using this model, biologists can access details of one particular execution of a workflow, compare results produced by different executions, and plan new experiments more efficiently. In addition to this, a provenance simulator was created, which facilitates the inclusion of provenance data of one genome project workflow execution. Finally, we discuss one case study, which aims to identify genes involved in specific metabolic pathways of Bacillus cereus, as well as to compare this isolate with other phylogenetic related bacteria from the Bacillus group. B. cereus is an extremophilic bacteria, collected in warm water in the Midwestern Region of Brazil, its DNA samples having been sequenced with an NGS machine. PMID:24564294

  8. Provenance in neuroimaging.

    PubMed

    Mackenzie-Graham, Allan J; Van Horn, John D; Woods, Roger P; Crawford, Karen L; Toga, Arthur W

    2008-08-01

    Provenance, the description of the history of a set of data, has grown more important with the proliferation of research consortia-related efforts in neuroimaging. Knowledge about the origin and history of an image is crucial for establishing data and results quality; detailed information about how it was processed, including the specific software routines and operating systems that were used, is necessary for proper interpretation, high fidelity replication and re-use. We have drafted a mechanism for describing provenance in a simple and easy to use environment, alleviating the burden of documentation from the user while still providing a rich description of an image's provenance. This combination of ease of use and highly descriptive metadata should greatly facilitate the collection of provenance and subsequent sharing of data. PMID:18519166

  9. Depositional and provenance record of the Paleogene transition from foreland to hinterland basin evolution during Andean orogenesis, northern Middle Magdalena Valley Basin, Colombia

    NASA Astrophysics Data System (ADS)

    Moreno, Christopher J.; Horton, Brian K.; Caballero, Victor; Mora, Andrés; Parra, Mauricio; Sierra, Jair

    2011-10-01

    The Central Cordillera and Eastern Cordillera of the northern Andes form the topographic flanks of the north-trending Magdalena Valley Basin. Constraining the growth of these ranges and intervening basin has implications for Andean shortening and the transformation from a foreland to hinterland basin configuration. We present sedimentological, paleocurrent, and sandstone petrographic results from Cenozoic type localities to provide insights into the tectonic history of the northern Middle Magdalena Valley Basin of Colombia. In the Nuevo Mundo Syncline, the mid-Paleocene transition from marine to nonmarine deposystems of the Lisama Formation corresponds with a paleocurrent shift from northward to eastward transport. These changes match detrital geochronological evidence for a contemporaneous shift from cratonic (Amazonian) to orogenic (Andean) provenance, suggesting initial shortening-related uplift of the Central Cordillera and foreland basin generation in the Magdalena Valley by mid-Paleocene time. Subsequent establishment of a meandering fluvial system is recorded in lower-middle Eocene strata of the lower La Paz Formation. Eastward paleocurrents in mid-Paleocene through uppermost Eocene fluvial deposits indicate a continuous influence of western sediment source areas. However, at the upper middle Eocene (˜40 Ma) boundary between the lower and upper La Paz Formation, sandstone compositions show a drastic decrease in lithic content, particularly lithic volcanic fragments. This change is accompanied by a facies shift from mixed channel and overbank facies to thick, amalgamated braided fluvial deposits of possible fluvial megafans, reflecting changes in both the composition and proximity of western sediment sources. We attribute these modifications to the growing influence of exhumed La Cira-Infantas paleohighs in the axial Magdalena Valley, features presently buried beneath upper Eocene-Quaternary basin fill along the western flank of the Nuevo Mundo Syncline. In

  10. Late Cretaceous protolith age and provenance of the Pelona and Orocopia Schists, southern California: Implications for evolution of the Cordilleran margin

    SciTech Connect

    Jacobson, C.E.; Barth, A.P.; Grove, M.

    2000-03-01

    The Pelona and Orocopia Schists are southern members of a eugeoclinal terrane that structurally underlies a large part of southwestern North America. Ion-microprobe U-Pb ages of >100 detrital zircons from three widely spaced samples of these two units indicate that deposition occurred after 70--80 Ma. Moreover, the distribution of zircon ages, including a significant peak centered ca. 1.7 Ga, implies a major contribution f detritus from the Mojave Desert and Transverse Ranges of southern California. Recrystallization of the schists at depths of 20--35 km occurred within 10--15 m.y. of deposition, which requires underthrusting at minimum rates of {approximately}4--12 mm/yr for reasonable thrust dips. Considering that similar processes formed the more northern Rand Schist at somewhat earlier times, results indicate a southward progression in timing of deformation for the schists' protoliths. This result is at odds with northward migration of deformation implied by the Baja British Columbia hypothesis. The age and provenance of the schist's protoliths are consistent with models that derive the schists from either the Franciscan Complex or Great Valley Group.

  11. Oxygen Sensing for Industrial Safety — Evolution and New Approaches

    PubMed Central

    Willett, Martin

    2014-01-01

    The requirement for the detection of oxygen in industrial safety applications has historically been met by electrochemical technologies based on the consumption of metal anodes. Products using this approach have been technically and commercially successful for more than three decades. However, a combination of new requirements is driving the development of alternative approaches offering fresh opportunities and challenges. This paper reviews some key aspects in the evolution of consumable anode products and highlights recent developments in alternative technologies aimed at meeting current and anticipated future needs in this important application. PMID:24681673

  12. Multi-Model approach to reconstruct the Mediterranean Freshwater Evolution

    NASA Astrophysics Data System (ADS)

    Simon, Dirk; Marzocchi, Alice; Flecker, Rachel; Lunt, Dan; Hilgen, Frits; Meijer, Paul

    2016-04-01

    Today the Mediterranean Sea is isolated from the global ocean by the Strait of Gibraltar. This restricted nature causes the Mediterranean basin to react more sensitively to climatic and tectonic related phenomena than the global ocean. Not just eustatic sea-level and regional river run-off, but also gateway tectonics and connectivity between sub-basins are leaving an enhanced fingerprint in its geological record. To understand its evolution, it is crucial to understand how these different effects are coupled. The Miocene-Pliocene sedimentary record of the Mediterranean shows alternations in composition and colour and has been astronomically tuned. Around the Miocene-Pliocene Boundary the most extreme changes occur in the Mediterranean Sea. About 6% of the salt in the global ocean deposited in the Mediterranean Region, forming an approximately 2 km thick salt layer, which is still present today. This extreme event is named the Messinian Salinity Crisis (MSC, 5.97-5.33 Ma). The gateway and climate evolution is not well constrained for this time, which makes it difficult to distinguish which of the above mentioned drivers might have triggered the MSC. We, therefore, decided to tackle this problem via a multi-model approach: (1) We calculate the Mediterranean freshwater evolution via 30 atmosphere-ocean-vegetation simulations (using HadCM3L), to which we fitted to a function, using a regression model. This allows us to directly relate the orbital curves to evaporation, precipitation and run off. The resulting freshwater evolution can be directly correlated to other sedimentary and proxy records in the late Miocene. (2) By feeding the new freshwater evolution curve into a box/budget model we can predict the salinity and strontium evolution of the Mediterranean for a certain Atlantic-Mediterranean gateway. (3) By comparing these results to the known salinity thresholds of gypsum and halite saturation of sea water, but also to the late Miocene Mediterranean strontium

  13. A systematic approach to design for lifelong aircraft evolution

    NASA Astrophysics Data System (ADS)

    Lim, Dongwook

    This research proposes a systematic approach with which the decision makers can evaluate the value and risk of a new aircraft development program, including potential derivative development opportunities. The proposed Evaluation of Lifelong Vehicle Evolution (EvoLVE) method is a two- or multi-stage representation of the aircraft design process that accommodates initial development phases as well as follow-on phases. One of the key elements of this method is the Stochastic Programming with Recourse (SPR) technique, which accounts for uncertainties associated with future requirements. The remedial approach of SPR in its two distinctive problem-solving steps is well suited to aircraft design problems where derivatives, retrofits, and upgrades have been used to fix designs that were once but no longer optimal. The solution approach of SPR is complemented by the Risk-Averse Strategy Selection (RASS) technique to gauge risk associated with vehicle evolution options. In the absence of a full description of the random space, a scenario-based approach captures the randomness with a few probable scenarios and reveals implications of different future events. Last, an interactive framework for decision-making support allows simultaneous navigation of the current and future design space with a greater degree of freedom. A cantilevered beam design problem was set up and solved using the SPR technique to showcase its application to an engineering design setting. The full EvoLVE method was conducted on a notional multi-role fighter based on the F/A-18 Hornet.

  14. Provenance of metasedimentary rocks of the Western Pernambuco-Alagoas Domain: Contribution to understand the crustal evolution of southern Borborema Province

    NASA Astrophysics Data System (ADS)

    Cruz, Rodrigo Fabiano da; Pimentel, Márcio Martins; Accioly, Ana Cláudia de Aguiar

    2014-12-01

    The Borborema Province is a complex neoproterozoic orogen in northeastern Brazil, made of a mosaic of fault-bounded terrains and several metassedimentary sequences. In the present work, new zircon U-Pb provenance data for metasedimentary rocks in the Western Pernambuco-Alagoas Domain, southern part of the Province, are reported. Detrital zircon ages range from Archean to Neoproterozoic. Three samples of the Cabrobó Complex were investigated: (i) sillimanite-kyanite-garnet-biotite schist, which presented mostly Ediacaran and Cryogenian detrital zircon ages (youngest zircon at ca. 554 Ma) indicating erosion of neoproterozoic sources, (ii) garnet-biotite schist, which has a dominant Tonian/Stenian population, a less abundant Cryogenian (youngest zircon age at ca. 643 Ma) as well as Paleoproterozoic and Archean zircon grains, and (iii) tourmaline-muscovite quartzite, which contains detrital zircon varying in age between ca. 2.08 Ga and 1.57 Ga, and an abundant population close to the Meso/Paleoproterozoic boundary, possibly associated with the erosion of rocks formed during the Statherian taphrogenesis, known in the central part of the São Francisco Craton as well as in other areas of the Borborema Province. Two samples of the Riacho Seco Metasedimentary Complex were also investigated: (i) a biotite schist with a dominant population presenting ages mostly between 2.3 and 2.7 Ga (youngest zircon age at ca. 2023 Ma) and (ii) a magnetite-biotite-muscovite quartzite, having detrital zircon grains with ages ranging between ca. 1.9 and 2.7 Ga. The sedimentary rocks of the Riacho Seco Complex may have their origin related to the erosion of sources within the São Francisco Craton. The data for the Riacho Seco metasedimentary rocks, however, are not conclusive with respect to the depositional age of the original sedimentary rocks. The sequence might represent exposure of an old (Paleoproterozoic) sedimentary pile or, alternatively, it comprises a neoproterozoic passive

  15. Sandstone provenance and tectonic evolution of the Xiukang Mélange from Neotethyan subduction to India-Asia collision (Yarlung-Zangbo suture, south Tibet)

    NASA Astrophysics Data System (ADS)

    An, Wei; Hu, Xiumian; Garzanti, Eduardo

    2016-04-01

    The Xiukang Mélange of the Yarlung-Zangbo suture zone in south Tibet documents low efficiency of accretion along the southern active margin of Asia during Cretaceous Neotethyan subduction, followed by final development during the early Paleogene stages of the India-Asia collision. Here we investigate four transverses in the Xigaze area (Jiding, Cuola Pass, Riwuqi and Saga), inquiry the composition in each transverse, and present integrated petrologic, U-Pb detrital-zircon geochronology and Hf isotope data on sandstone blocks. In fault contact with the Yarlung-Zangbo Ophiolite to the north and the Tethyan Himalaya to the south, the Xiukang mélange can be divided into three types: serpentinite-matrix mélange composed by broken Yarlung-Zangbo Ophiolite, thrust-sheets consisting mainly chert, quartzose or limestone sheets(>100m) with little intervening marix, and mudstone-matrix mélange displaying typical blocks-in-matrix texture. While serpentinite-matrix mélange is exposed adjacent to the ophiolite, distributions of thrust-sheets and blocks in mudstone-matrix mélange show along-strike diversities. For example, Jiding transverse is dominant by chert sheets and basalt blocks with scarcely sandstone blocks, while Cuola Pass and Saga transverses expose large amounts of limestone/quartzarenite sheets in the north and volcaniclastic blocks in the south. However, turbidite sheets and volcaniclastic blocks are outcropped in the north Riwuqi transverse with quartzarenite blocks preserved in the south. Three groups of sandstone blocks/sheets with different provenance and depositional setting are distinguished by their petrographic, geochronological and isotopic fingerprints. Sheets of turbiditic quartzarenite originally sourced from the Indian continent were deposited in pre-Cretaceous time on the northernmost edge of the Indian passive margin and eventually involved into the mélange at the early stage of the India-Asia collision. Two distinct groups of volcaniclastic

  16. Evolution of genome size: new approaches to an old problem.

    PubMed

    Petrov, D A

    2001-01-01

    Eukaryotic genomes come in a wide variety of sizes. Haploid DNA contents (C values) range > 80,000-fold without an apparent correlation with either the complexity of the organism or the number of genes. This puzzling observation, the C-value paradox, has remained a mystery for almost half a century, despite much progress in the elucidation of the structure and function of genomes. Here I argue that new approaches focussing on the genetic mechanisms that generate genome-size differences could shed much light on the evolution of genome size. PMID:11163918

  17. Sm-Nd isotopic study of Precambrian/Cambrian sedimentary provenance in the Great Basin and implications for the tectonic evolution of the western US

    SciTech Connect

    Farmer, G.L.

    1985-01-01

    The Nd isotopic compositions and Sm-Nd model ages were determined for 14 Precambrian to Cambrian clastic miogeoclinal and 2 Lower Paleozoic eugeoclinal metasedimentary rocks in the Great Basin to determine the sediment source regions and constrain the tectonic evolution of the western margin of the continental US Upper Precambrian (McCoy Creek Group-MCG) and Lower Cambrian miogeoclinal sandstones and shales have homogeneous 147SM/144Nd values (.110 to .119) but show a regional variation in measured element of/sub Nd/, from values of -18 and -26 (T/sub DM/=1.9 and 2.5Ga) in the Pilot and Ruby Ranges in N. Nevada, to values clustering at -11 and -18 (T/sub DM/=1.3 and 1.9Ga) in the Deep Creek and Schell Creek Ranges in the east-central Great Basin. The isotopic variations in the MCG correspond spatially to changes in the element of/sub ND/(0) and T/sub DM/ Precambrian basement adjacent to the miogeocline, suggesting that the MCG were derived from these crustal terranes and were deposited close to the paleocontinental margin of the western US. An element of/sub Nd/(0)=22.14 (T/sub DM/=2.1 Ga) for deeper water miogeoclinal sediment in the southern Great Basin (Wyman Fm-White Mountains, California) requires a source either in nearby T/sub DM/=2.2Ga crust in the S. Sierra Nevada (Bennett and DePaolo, 1984), or in T/sub DM/>2.0Ga crustal terranes to the north, with the sediment having been transported southward via Precambrian longshore currents. Feldspathic sandstone of the Cambrian Harmony Formation in north-central Nevada has element of/sub Nd/(0)=-25.22 (T/sub DM/=2.4Ga), consistent with a northerly source in Archean crust of present-day Idaho, while Ordovician shale of the Vinini Fm. in central Nevada has element of/sub Nd/(0)=-17.6, identical to values for the MCG exposed directly to the east.

  18. Provenance Store Evaluation

    SciTech Connect

    Paulson, Patrick R.; Gibson, Tara D.; Schuchardt, Karen L.; Stephan, Eric G.

    2008-03-01

    Requirements for the provenance store and access API are developed. Existing RDF stores and APIs are evaluated against the requirements and performance benchmarks. The team’s conclusion is to use MySQL as a database backend, with a possible move to Oracle in the near-term future. Both Jena and Sesame’s APIs will be supported, but new code will use the Jena API

  19. Analytical Approach to Eigen-Emittance Evolution in Storage Rings

    SciTech Connect

    Nash, Boaz; /SLAC

    2006-05-16

    This dissertation develops the subject of beam evolution in storage rings with nearly uncoupled symplectic linear dynamics. Linear coupling and dissipative/diffusive processes are treated perturbatively. The beam distribution is assumed Gaussian and a function of the invariants. The development requires two pieces: the global invariants and the local stochastic processes which change the emittances, or averages of the invariants. A map based perturbation theory is described, providing explicit expressions for the invariants near each linear resonance, where small perturbations can have a large effect. Emittance evolution is determined by the damping and diffusion coefficients. The discussion is divided into the cases of uniform and non-uniform stochasticity, synchrotron radiation an example of the former and intrabeam scattering the latter. For the uniform case, the beam dynamics is captured by a global diffusion coefficient and damping decrement for each eigen-invariant. Explicit expressions for these quantities near coupling resonances are given. In many cases, they are simply related to the uncoupled values. Near a sum resonance, it is found that one of the damping decrements becomes negative, indicating an anti-damping instability. The formalism is applied to a number of examples, including synchrobetatron coupling caused by a crab cavity, a case of current interest where there is concern about operation near half integer {nu}{sub x}. In the non-uniform case, the moment evolution is computed directly, which is illustrated through the example of intrabeam scattering. Our approach to intrabeam scattering damping and diffusion has the advantage of not requiring a loosely-defined Coulomb Logarithm. It is found that in some situations there is a small difference between our results and the standard approaches such as Bjorken-Mtingwa, which is illustrated by comparison of the two approaches and with a measurement of Au evolution in RHIC. Finally, in combining IBS

  20. Time Evolution of Pulsar Magnetosphere - An Implicit Approach

    NASA Astrophysics Data System (ADS)

    Sreekumar, Sushilkumar; Schlegel, Eric

    2015-04-01

    The Magnetosphere for a pulsar plays a very significant role in its evolution and is regarded as an ideal site for high energy emission. Understanding the structure, dynamics and evolution of the magnetosphere is important. Contopoulos et al. (CKF, 1999) were able to demonstrate numerically the importance of current sheets (CS) along with the Goldreich-Julian charge density (1969). In addition, Spitkovsky (2006) was also able to numerically solve the time dependent hyperbolic system of equations and validate the existence of CS within the Alfvén radius and beyond. However the explicitnature of the numerical approach restricts the size of the time step, which results in an unresolved current sheet. Currently the CKF type magnetosphere is the new benchmark in pulsar modelling and hence CS and its distribution plays a key role. Its contribution in pulsar spin down mechanism, high energy emissions, flux outflow, reconnection events, acceleration mechanisms and locations is currently not understood and as a result resolution of the CS is critical. It is with this motivation that our group has decided to develop a computationally challenging implicit code under the force-free electrodynamics. With implicit approach the Courant number can be sufficiently large which will not only help to resolve the CS and spatial resolution but will also guide us within the high conductivity limit of resistive solutions, where the traditional explicit method becomes too expensive.

  1. Preparing Biology Teachers to Teach Evolution in a Project-Based Approach

    ERIC Educational Resources Information Center

    Cook, Kristin; Buck, Gayle; Park Rogers, Meredith

    2012-01-01

    This study investigates a project-based learning (PBL) approach to teaching evolution to inform efforts in teacher preparation. Data analysis of a secondary biology educator teaching evolution through a PBL approach illuminated: (1) active student voice, which allowed students to reflect on their positioning on evolution and consider multiple…

  2. Evolution of inhomogeneous condensates: Self-consistent variational approach

    SciTech Connect

    Boyanovsky, D.; Cooper, F.; de Vega, H.J.; Sodano, P.

    1998-07-01

    We establish a self-consistent variational framework that allows us to study numerically the non-equilibrium evolution of non-perturbative inhomogeneous field configurations including quantum back reaction effects. After discussing the practical merits and disadvantages of different approaches we provide a closed set of local and renormalizable update equations that determine the dynamical evolution of inhomogeneous condensates and can be implemented numerically. These incorporate self-consistently the back reaction of quantum fluctuations and particle production. This program requires the solution of a self-consistent inhomogeneous problem to provide initial Cauchy data for the inhomogeneous condensates and Green`s functions. We provide a simple solvable ansatz for such an initial value problem for the sine-Gordon and {phi}{sup 4} quantum field theories in one spatial dimension. We compare exact known results of the sine-Gordon model to this simple ansatz. We also study the linear sigma model in the large N limit in three spatial dimensions as a microscopic model for pion production in ultrarelativistic collisions. We provide a solvable self-consistent ansatz for the initial value problem with cylindrical symmetry. For this case we also obtain a closed set of local and renormalized update equations that can be numerically implemented. A novel phenomenon of spinodal instabilities and pion production arises as a result of a Klein paradox for large amplitude inhomogeneous condensate configurations. {copyright} {ital 1998} {ital The American Physical Society}

  3. New approaches to enzymatic glycoside synthesis through directed evolution.

    PubMed

    Kittl, Roman; Withers, Stephen G

    2010-07-01

    The expanding field of glycobiology requires tools for the synthesis of structurally defined oligosaccharides and glycoconjugates, while any potential therapeutic applications of sugar-based derivates would require access to substantial quantities of such compounds. Classical chemical approaches are not well suited for such large-scale syntheses, thus enzymatic approaches are sought. Traditional routes to the enzymatic assembly of oligosaccharides have involved the use of either Nature's own biosynthetic enzymes, the glycosyl transferases, or glycosidases run in transglycosylation mode. However, each approach has drawbacks that have limited its application. Glycosynthases are mutant glycosidases in which the catalytic nucleophile has been replaced by mutation, inactivating them as hydrolases. When used in conjunction with glycosyl fluorides of the opposite anomeric configuration to that of the substrate, these enzymes function as highly efficient transferases, frequently giving stoichiometric yields of products. Further improvements can be obtained through directed evolution of the gene encoding the enzyme in question, but this requires the ability to screen very large libraries of catalysts. In this review we survey new screening methods for the formation of glycosidic linkages using high-throughput techniques, such as FACS, chemical complementation, and robot-assisted ELISA assays. Enzymes were evolved to have higher catalytic activity with their natural substrates, to show altered substrate specificities or to be promiscuous for efficient application in oligosaccharide, glycolipid, and glycoprotein synthesis. PMID:20427037

  4. A systemic approach for modeling biological evolution using Parallel DEVS.

    PubMed

    Heredia, Daniel; Sanz, Victorino; Urquia, Alfonso; Sandín, Máximo

    2015-08-01

    A new model for studying the evolution of living organisms is proposed in this manuscript. The proposed model is based on a non-neodarwinian systemic approach. The model is focused on considering several controversies and open discussions about modern evolutionary biology. Additionally, a simplification of the proposed model, named EvoDEVS, has been mathematically described using the Parallel DEVS formalism and implemented as a computer program using the DEVSLib Modelica library. EvoDEVS serves as an experimental platform to study different conditions and scenarios by means of computer simulations. Two preliminary case studies are presented to illustrate the behavior of the model and validate its results. EvoDEVS is freely available at http://www.euclides.dia.uned.es. PMID:26116878

  5. Evolution of cyanobacterial morphotypes: Taxa required for improved phylogenomic approaches.

    PubMed

    Schirrmeister, Bettina E; Anisimova, Maria; Antonelli, Alexandre; Bagheri, Homayoun C

    2011-07-01

    Within prokaryotes cyanobacteria represent one of the oldest and morphologically most diverse phyla on Earth. The rise of oxygen levels in the atmosphere 2.32-2.45 billion years ago is assigned to the photosynthetic activity of ancestors from this phylum. Subsequently cyanobacteria were able to adapt to various habitats evolving a comprehensive set of different morphotypes. In a recent study we showed that this evolution is not a gradual transition from simple unicellular to more complex multicellular forms as often assumed. Instead complexity was lost several times and regained at least once. An understanding of the genetic basis of these transitions would be further strengthened by phylogenomic approaches. However, considering that new methods for phylogenomic analyses are emerging, it is unfortunate that genomes available today are comprised of an unbalanced sampling of taxa. We propose avenues to remedy this by identifying taxa that would improve the representation of phylogenetic diversity in this phylum. PMID:21966561

  6. Relational Neural Evolution Approach to Bank Failure Prediction

    NASA Astrophysics Data System (ADS)

    Abudu, Bolanle; Markose, Sheri

    2007-12-01

    Relational neural networks as a concept offers a unique opportunity for improving classification accuracy by exploiting relational structure in data. The premise is that a relational classification technique, which uses information implicit in relationships, should classify more accurately than techniques that only examine objects in isolation. In this paper, we study the use of relational neural networks for predicting bank failure. Alongside classical financial ratios normally used as predictor variables, we introduced new relational variables for the network. The relational neural network structure, specified as a combination of feed forward and recurrent neural networks, is determined by bank data through neuro-evolution. We discuss empirical results comparing performance of the relational approach to standard propositional methods used for bank failure prediction.

  7. Relational Neural Evolution Approach to Bank Failure Prediction

    SciTech Connect

    Abudu, Bolanle; Markose, Sheri

    2007-12-26

    Relational neural networks as a concept offers a unique opportunity for improving classification accuracy by exploiting relational structure in data. The premise is that a relational classification technique, which uses information implicit in relationships, should classify more accurately than techniques that only examine objects in isolation. In this paper, we study the use of relational neural networks for predicting bank failure. Alongside classical financial ratios normally used as predictor variables, we introduced new relational variables for the network. The relational neural network structure, specified as a combination of feed forward and recurrent neural networks, is determined by bank data through neuro-evolution. We discuss empirical results comparing performance of the relational approach to standard propositional methods used for bank failure prediction.

  8. Provenance for Environmental Cyberenvironments

    NASA Astrophysics Data System (ADS)

    Futrelle, J.

    2006-12-01

    Scientific collaboration is a complex distributed process that spans disciplinary, organizational, and spatiotemporal boundaries. As information technology (IT) is deployed in scientific communities, new techniques are required to manage these complex processes so that the digital artifacts associated with scientific knowledge can be used as effectively as possible. Cyberenvironments (CE) propose to extend current IT infrastructure to support distributed, collaborative work, comprising online collaboration tools, distributed data management, distributed processing, and social networking analysis. The Environmental Cyberinfrastructure Demonstrator (ECID) project at the National Center for Supercomputing Applications (NCSA) is exploring cyberenvironment directions for environmental research, motivated in particular by the requirements being identified through the NSF's CLEANER/CUASHI/WATERS environmental observatory planning activities. These requirements entail providing integrated access to an evolving set of community sensor networks, data collections, models, analysis tools, literature, and community members, and tracking the relationships between them. The metadata and provenance information required to support resource discovery and information fusion to support new scientific endeavors is anticipated to come from a variety of sources including human inputs, direct reporting from individual tools, and inferences from observations of human and system activities and to evolve over time. At NCSA, we have been developing a lightweight, distributed infrastructure for managing metadata and provenance information and, through ECID, applying it in support of environmental observatory scenarios. This poster will provide an overview of the technical infrastructure being created, describe the set of tools and types of information being managed in ECID, and outline concepts such as sharing of best-practice workflows and community model validation that would leverage this

  9. A quantitative approach to evolution of music and philosophy

    NASA Astrophysics Data System (ADS)

    Vieira, Vilson; Fabbri, Renato; Travieso, Gonzalo; Oliveira, Osvaldo N., Jr.; da Fontoura Costa, Luciano

    2012-08-01

    The development of new statistical and computational methods is increasingly making it possible to bridge the gap between hard sciences and humanities. In this study, we propose an approach based on a quantitative evaluation of attributes of objects in fields of humanities, from which concepts such as dialectics and opposition are formally defined mathematically. As case studies, we analyzed the temporal evolution of classical music and philosophy by obtaining data for 8 features characterizing the corresponding fields for 7 well-known composers and philosophers, which were treated with multivariate statistics and pattern recognition methods. A bootstrap method was applied to avoid statistical bias caused by the small sample data set, with which hundreds of artificial composers and philosophers were generated, influenced by the 7 names originally chosen. Upon defining indices for opposition, skewness and counter-dialectics, we confirmed the intuitive analysis of historians in that classical music evolved according to a master-apprentice tradition, while in philosophy changes were driven by opposition. Though these case studies were meant only to show the possibility of treating phenomena in humanities quantitatively, including a quantitative measure of concepts such as dialectics and opposition, the results are encouraging for further application of the approach presented here to many other areas, since it is entirely generic.

  10. Mass balance approaches to understanding evolution of dripwater chemistry

    NASA Astrophysics Data System (ADS)

    Fairchild, I. J.; Baker, A.; Andersen, M. S.; Treble, P. C.

    2015-12-01

    Forward and inverse modelling of dripwater chemistry is a fast-developing area in speleothem science. Such approaches can incorporate theoretical, parameterized or observed relationships between forcing factors and water composition, but at the heart is mass balance: a fundamental principle that provides important constraints. Mass balance has been used in speleothem studies to trace the evolution of dissolved inorganic carbon and carbon isotopes from soil to cave, and to characterize the existence and quantification of prior calcite precipitation (PCP) based on ratios of Mg and Sr to Ca. PCP effects can dominate slow drips, whereas fast drips are more likely to show a residual variability linked to soil-biomass processes. A possible configuration of a more complete mass balance model is illustrated in the figure. Even in humid temperate climates, evapotranspiration can be 50% of total atmospheric precipitation leading to substantially raised salt contents and there can be significant exchange with biomass. In more arid settings, at least seasonal soil storage of salts is likely. Golgotha Cave in SW Australia is in a Mediterranean climate with a strong summer soil moisture deficit. The land surface is forested leading to large ion fluxes related to vegetation. There are also periodic disturbances related to fire. Mass balance approaches have been applied to an 8-year monitoring record. Inter-annual trends of elements coprecipitated in speleothems from fast drips are predicted to be dominated by biomass effects.

  11. Detrital zircon U-Pb geochronology and stratigraphy of the Cretaceous Sanjiang Basin in NE China: Provenance record of an abrupt tectonic switch in the mode and nature of the NE Asian continental margin evolution

    NASA Astrophysics Data System (ADS)

    Zhang, Feng-Qi; Chen, Han-Lin; Batt, Geoffrey E.; Dilek, Yildirim; A, Min-Na; Sun, Ming-Dao; Yang, Shu-Feng; Meng, Qi-An; Zhao, Xue-Qin

    2015-12-01

    The age spectra obtained from 505 spots of detrital zircon U-Pb ages of five representative sandstone samples from the Sanjiang Basin in NE China point to a significant change in its provenance during the Coniacian-Santonian. The predominant detrital source for the Sanjiang Basin during the early Cretaceous was the Zhangguangcai Range magmatic belt and Jiamusi Block along its western and southern periphery, whereas it changed in the late Cretaceous to its eastern periphery. The timing of these inferred changes in the detrital source regions and drainage patterns nearly coincide with the age of a regional unconformity in and across the basin. The time interval of non-deposition and unconformity development was coeval with a transitional period between an extensional tectonic regime in the early Cretaceous and a contractional deformation episode in the late Cretaceous. The Sanjiang Basin evolved during this time window from a backarc to a foreland basin. The migration of the coastal orogenic belt and the fold and thrust belt development farther inland during the late Cretaceous marked the onset of regional-scale shortening and surface uplift in the upper plate of a flat (or very shallow-dipping) subduction zone. The stratigraphic record, the detrital source and geochronology of the basinal strata, and the internal structure of the Sanjiang Basin present, therefore, an important record of a tectonic switch in the nature of continental margin evolution of Northeast Asia during the late Mesozoic.

  12. Detrital zircon U-Pb ages and Hf isotopes of Permo-Carboniferous sandstones in central Inner Mongolia, China: Implications for provenance and tectonic evolution of the southeastern Central Asian Orogenic Belt

    NASA Astrophysics Data System (ADS)

    Chen, Yan; Zhang, Zhicheng; Li, Ke; Yu, Haifei; Wu, Tairan

    2016-03-01

    The tectonic setting of the southeastern Central Asian Orogenic Belt (CAOB) during the Late Paleozoic has been debated for many years. Provenance analysis of Permo-Carboniferous sedimentary rocks can effectively address this issue. In this study, eight sandstone samples were collected for zircon U-Pb and Lu-Hf isotopic analyses combined with petrographic analysis. Framework petrography and zircon morphology suggest that the samples were from recycled orogen of an igneous origin. Carboniferous rocks, with a significant age peak at 432 Ma and εHf (t) values of - 9.0 to 13.6, were mainly derived from Early to Mid-Paleozoic magmatic rocks and deposited in a piedmont zone, namely, the margin of an inland sea. Permian rocks, mostly with age peaks at 445 Ma and/or 280 Ma and εHf (t) values of - 25.2 to 11.4, dominantly originated from a pre-existing Early to Mid-Paleozoic magmatic arc and Late Paleozoic igneous rocks. These rocks formed in restricted basins of the piedmont and intermountain zones. Based on zircon spectral discrimination, sedimentary environmental analysis, and previous studies, this study supports the interpretation that the southeastern CAOB entered stages of extension and rifting during the Late Paleozoic. In the end, this study proposes a tectonic-paleogeographic reconstruction to explain the tectonic evolution of the southeastern CAOB and the exhumation-transportation-deposition processes between the basins and ranges developed in this orogen.

  13. An automaton approach for waiting times in DNA evolution.

    PubMed

    Behrens, Sarah; Nicaud, Cyril; Nicodème, Pierre

    2012-05-01

    In a recent article, Behrens and Vingron (J. Comput. Biol. 17/12, 2010) compute waiting times for k-mers to appear during DNA evolution under the assumption that the considered k-mers do not occur in the initial DNA sequence, an issue arising when studying the evolution of regulatory DNA sequences with regard to transcription factor (TF) binding site emergence. The mathematical analysis underlying their computation assumes that occurrences of words under interest do not overlap. We relax here this assumption by use of an automata approach. In an alphabet of size 4 like the DNA alphabet, most words have no or a low autocorrelation; therefore, globally, our results confirm those of Behrens and Vingron. The outcome is quite different when considering highly autocorrelated k-mers; in this case, the autocorrelation pushes down the probability of occurrence of these k-mers at generation 1 and, consequently, increases the waiting time for apparition of these k-mers up to 40%. An analysis of existing TF binding sites unveils a significant proportion of k-mers exhibiting autocorrelation. Thus, our computations based on automata greatly improve the accuracy of predicting waiting times for the emergence of TF binding sites to appear during DNA evolution. We do the computation in the Bernoulli or M0 model; computations in the M1 model, a Markov model of order 1, are more costly in terms of time and memory but should produce similar results. While Behrens and Vingron considered specifically promoters of length 1000, we extend the results to promoters of any size; we exhibit the property that the probability that a k-mer occurs at generation time 1 while being absent at time 0 behaves linearly with respect to the length of the promoter, which induces a hyperbolic behaviour of the waiting time of any k-mer with respect to the length of the promoter. The C code is available at www.lipn.univ-paris13.fr/∼nicodeme/ . PMID:22468677

  14. An evolution of image source camera attribution approaches.

    PubMed

    Jahanirad, Mehdi; Wahab, Ainuddin Wahid Abdul; Anuar, Nor Badrul

    2016-05-01

    researchers, are also critically analysed and further categorised into four different classes, namely, optical aberrations based, sensor camera fingerprints based, processing statistics based and processing regularities based, to present a classification. Furthermore, this paper aims to investigate the challenging problems, and the proposed strategies of such schemes based on the suggested taxonomy to plot an evolution of the source camera attribution approaches with respect to the subjective optimisation criteria over the last decade. The optimisation criteria were determined based on the strategies proposed to increase the detection accuracy, robustness and computational efficiency of source camera brand, model or device attribution. PMID:27060542

  15. Interpreting Evidence: An Approach to Teaching Human Evolution in the Classroom

    ERIC Educational Resources Information Center

    DeSilva, Jeremy

    2004-01-01

    Paleoanthropology, which is the study of human evolution through fossil records, can be used as a tool for teaching human evolution in the classrooms. An updated approach to teaching human evolution and a model for explaining what is science and how it is done, is presented.

  16. Basaltic island sand provenance

    SciTech Connect

    Marsaglia, K.M. . Dept. of Geological Sciences)

    1992-01-01

    The Hawaiian Islands are an ideal location to study basaltic sand provenance in that they are a series of progressively older basaltic shield volcanoes with arid to humid microclimates. Sixty-two sand samples were collected from beaches on the islands of Hawaii, Maui, Oahu and Kauai and petrographically analyzed. The major sand components are calcareous bioclasts, volcanic lithic fragments, and monomineralic grains of dense minerals and plagioclase. Proportions of these components vary from island to island, with bioclastic end members being more prevalent on older islands exhibiting well-developed fringing reef systems and volcanic end members more prevalent on younger, volcanically active islands. Climatic variations across the island of Hawaii are reflected in the percentage of weathered detritus, which is greater on the wetter, northern side of the island. The groundmass of glassy, basaltic lithics is predominantly black tachylite, with lesser brown sideromelane; microlitic and lathwork textures are more common than holohyaline vitric textures. Other common basaltic volcanic lithic fragments are holocrystalline aggregates of silt-sized pyroxene or olivine, opaque minerals and plagioclase. Sands derived from alkalic lavas are texturally and compositionally indistinguishable from sands derived from tholeiitic lavas. Although Hawaiian basaltic sands overlap in composition with magmatic arc-derived sands in terms of their relative QFL, QmPK and LmLvLs percentages, they are dissimilar in that they lack felsic components and are more enriched in lathwork volcanic lithic fragments, holocrystalline volcanic lithic fragments, and dense minerals.

  17. Star clusters evolution simulation on basement of linguo- combinatorial approach

    NASA Astrophysics Data System (ADS)

    Ignatyev, Mikhail B.

    2015-08-01

    Each of the clusters of star systems can be described using linguo- combinatorial approach through a formula that determines the number of arbitrary factors in the structure of equivalent equations as the number of combinations of n by m + 1, where n - number of stars in the cluster, m - number of constraints imposed on the stars cluster(M.Ignatyev “The linguo- combinatorial simulation in modern physics”\\\\ J. of Modern Physics,USA, 2012, Vol.1, No 1, p.7-11). Such clusters can be multiple, they can be combined into larger clusters or clusters can decay based on the effect of the collective. For example, if we have two clusters are characterized by the number of arbitrary coefficients S1 and S2, wherem1 + 1 m2 + 1S1 = C S2 = Cn1 n2then by imposing general restrictions mcol we will havem1 + m2 + mcol +1Scol = Cn1 + n2At the same time, depending on the specific parameters can be Scol > S1 + S2, when the union in collective increases the adaptive capabilities, and can be Scol < S1 + S2, where adaptive capacity of less than the sum of the collective adaptation a possibly initial clusters. In the first case, we can observe the effect of the formation of new large clusters, in the second case - the collapse of large clusters into smaller ones. The report deals with the simulation of the evolution of star clusters on the basement of linguo- combinatorial approach.

  18. Evolution and dispersal of the genus Homo: A landscape approach.

    PubMed

    Winder, Isabelle C; Devès, Maud H; King, Geoffrey C P; Bailey, Geoffrey N; Inglis, Robyn H; Meredith-Williams, Matthew

    2015-10-01

    The notion of the physical landscape as an arena of ecological interaction and human evolution is a powerful one, but its implementation at larger geographical and temporal scales is hampered by the challenges of reconstructing physical landscape settings in the geologically active regions where the earliest evidence is concentrated. We argue that the inherently dynamic nature of these unstable landscapes has made them important agents of biological change, creating complex topographies capable of selecting for, stimulating, obstructing or accelerating the latent and emerging properties of the human evolutionary trajectory. We use this approach, drawing on the concepts and methods of active tectonics, to develop a new perspective on the origins and dispersal of the Homo genus. We show how complex topography provides an easy evolutionary pathway to full terrestrialisation in the African context, and would have further equipped members of the genus Homo with a suite of adaptive characteristics that facilitated wide-ranging dispersal across ecological and climatic boundaries into Europe and Asia by following pathways of complex topography. We compare this hypothesis with alternative explanations for hominin dispersal, and evaluate it by mapping the distribution of topographic features at varying scales, and comparing the distribution of early Homo sites with the resulting maps and with other environmental variables. PMID:26235482

  19. Intelligent Resource Management for Local Area Networks: Approach and Evolution

    NASA Technical Reports Server (NTRS)

    Meike, Roger

    1988-01-01

    The Data Management System network is a complex and important part of manned space platforms. Its efficient operation is vital to crew, subsystems and experiments. AI is being considered to aid in the initial design of the network and to augment the management of its operation. The Intelligent Resource Management for Local Area Networks (IRMA-LAN) project is concerned with the application of AI techniques to network configuration and management. A network simulation was constructed employing real time process scheduling for realistic loads, and utilizing the IEEE 802.4 token passing scheme. This simulation is an integral part of the construction of the IRMA-LAN system. From it, a causal model is being constructed for use in prediction and deep reasoning about the system configuration. An AI network design advisor is being added to help in the design of an efficient network. The AI portion of the system is planned to evolve into a dynamic network management aid. The approach, the integrated simulation, project evolution, and some initial results are described.

  20. A Bayesian Approach to Constraining Dwarf Galaxy Evolution

    NASA Astrophysics Data System (ADS)

    Lotz, J. M.; Ferguson, H. C.

    2001-12-01

    We use a Bayesian - maximum likelihood analysis of the Hubble Deep Field to constrain the epoch of dwarf galaxy formation. Late formation of dwarf galaxies arises as a natural consequence of proposed solutions to the "over-cooling" problem in hierarchical structure formation. Although dwarf-sized halos are among the first objects to collapse out of a cold dark matter dominated universe, photo-ionization from the inter-galactic UV background and stellar feedback at early epochs may suppress or delay significant star formation in dwarf galaxies until redshifts ~ 1. Such late-forming dwarf galaxies may make up a portion of the population of the faint blue galaxies observed at intermediate redshifts. Previous attempts to understand the nature of the faint blue galaxy population have fit the binned number counts, luminosity functions, color and size distributions and compared the results to a handful of possible scenarios. Our approach sums the likelihood of observing each object in the HDF catalog given a dwarf galaxy formation scenario and computes the total likelihood of the given dwarf formation scenario. The parameters of the input model are then varied, and the model with the maximum total likelihood is determined. This technique does not bin the data in any way, tests a wide range of input model parameters, and allows us to quantify the goodness-of-fit and constraints on dwarf galaxy evolution.

  1. Tracking Provenance of Earth Science Data

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt; Yesha, Yelena; Halem, Milton

    2010-01-01

    Tremendous volumes of data have been captured, archived and analyzed. Sensors, algorithms and processing systems for transforming and analyzing the data are evolving over time. Web Portals and Services can create transient data sets on-demand. Data are transferred from organization to organization with additional transformations at every stage. Provenance in this context refers to the source of data and a record of the process that led to its current state. It encompasses the documentation of a variety of artifacts related to particular data. Provenance is important for understanding and using scientific datasets, and critical for independent confirmation of scientific results. Managing provenance throughout scientific data processing has gained interest lately and there are a variety of approaches. Large scale scientific datasets consisting of thousands to millions of individual data files and processes offer particular challenges. This paper uses the analogy of art history provenance to explore some of the concerns of applying provenance tracking to earth science data. It also illustrates some of the provenance issues with examples drawn from the Ozone Monitoring Instrument (OMI) Data Processing System (OMIDAPS) run at NASA's Goddard Space Flight Center by the first author.

  2. Provenance through Time

    NASA Astrophysics Data System (ADS)

    Chandler, C. L.; Groman, R. C.; Shepherd, A.; Allison, M. D.; Kinkade, D.; Rauch, S.; Wiebe, P. H.; Glover, D. M.

    2014-12-01

    The ability to reproduce scientific results is a cornerstone of the scientific method, and access to the data upon which the results are based is essential to reproducibility. Access to the data alone is not enough though, and research communities have recognized the importance of metadata (data documentation) to enable discovery and data access, and facilitate interpretation and accurate reuse. The Biological and Chemical Oceanography Data Management Office (BCO-DMO) was first funded in late 2006 by the National Science Foundation (NSF) Division of Ocean Sciences (OCE) Biology and Chemistry Sections to help ensure that data generated during NSF OCE funded research would be preserved and available for future use. The BCO-DMO was formed by combining the formerly independent data management offices of two marine research programs: the United States Joint Global Ocean Flux Study (US JGOFS) and the US GLOBal Ocean ECosystems Dynamics (US GLOBEC) program. Since the US JGOFS and US GLOBEC programs were both active (1990s) there have been significant changes in all aspects of the research data life cycle, and the staff at BCO-DMO has modified the way in which we manage data contributed to the office. The supporting documentation that describes each dataset was originally displayed as a human-readable text file retrievable via a Web browser. BCO-DMO still offers that form because our primary audience is marine researchers using Web browser clients; however we are seeing an increased demand to support machine client access. Metadata records from the BCO-DMO data system are now extracted and published out in a variety of formats. The system supports ISO 19115, FGDC, GCMD DIF, schema.org Dataset extension, formal publication with a DOI, and RDF with semantic markup including PROV-O, FOAF and more. In the 1990s, data documentation helped researchers locate data of interest and understand the provenance sufficiently to determine fitness for purpose. Today, providing data

  3. Analysis Traceability and Provenance for HEP

    NASA Astrophysics Data System (ADS)

    Shamdasani, Jetendr; McClatchey, Richard; Branson, Andrew; Kovács, Zsolt

    2015-12-01

    This paper presents the use of the CRISTAL software in the N4U project. CRISTAL was used to create a set of provenance aware analysis tools for the Neuroscience domain. This paper advocates that the approach taken in N4U to build the analysis suite is sufficiently generic to be able to be applied to the HEP domain. A mapping to the PROV model for provenance interoperability is also presented and how this can be applied to the HEP domain for the interoperability of HEP analyses.

  4. Formation and evolution of galaxies: Analytical and numerical approaches

    NASA Astrophysics Data System (ADS)

    Zhang, Bing

    2001-08-01

    The effects of viscosity and clumpiness are investigated in the context of the formation and the dynamical evolution of galaxies by analytical models and numerical simulations. The major motivation of this investigation is to study how these two factors can alter the angular momentum behavior of the galaxies formed in the bottom-up formation scenario as indicated by the hierarchical CDM cosmology. We analytically modify the standard disk formation model to incorporate the effect of viscous evolution. We derive generic analytic solutions for the disk-halo system after adiabatic compression of the dark halo, with free choice of the input virialized dark halo density profile and of the specific angular momentum distribution. We derive limits on the final density profile of the halo in the central regions due to the condensation of gas. The viscous evolution can redistribute angular momentum distribution by driving material inwards to form a proto- bulge which can be formed by the bar instability in the proto-disk, and by spreading gas to large radius to form pure exponential stellar disk if the viscous evolution timescale and star formation timescale are similar. The `disk-halo' conspiracy is found to be formed better by the disk-halo interaction during the viscous evolution of disk. We investigate the relationship between the assumed initial conditions, such as halo `formation', or assembly, redshift zf, spin parameter λ, baryonic fraction F, and final disk properties such as global star formation timescale, gas fraction, and bulge-to-disk ratio. We find that the present properties of disks, such as the scale length, are compatible with a higher initial formation redshift if the re-distribution by viscous evolution is included than if it is ignored. The numerical simulations confirm many results derived in the analytical model. Further it is found that pure viscous evolution can be unstable. Possibly feedback from star formation is required to maintain a stable

  5. Evolution of proteins and proteomes: a phylogenetics approach

    PubMed Central

    Gabaldón, Toni

    2007-01-01

    The study of evolutionary relationships among protein sequences was one of the first applications of bioinformatics. Since then, and accompanying the wealth of biological data produced by genome sequencing and other high-throughput techniques, the use of bioinformatics in general and phylogenetics in particular has been gaining ground in the study of protein and proteome evolution. Nowadays, the use of phylogenetics is instrumental not only to infer the evolutionary relationships among species and their genome sequences, but also to reconstruct ancestral states of proteins and proteomes and hence trace the paths followed by evolution. Here I survey recent progress in the elucidation of mechanisms of protein and proteome evolution in which phylogenetics has played a determinant role. PMID:19325853

  6. The Ecology of Language Evolution. Cambridge Approaches to Language Contact.

    ERIC Educational Resources Information Center

    Mufwene, Salikoko S.

    This book explores the development of creoles and other new languages, highlighting conceptual and methodological issues for genetic linguistics and discussing the significance of ecologies that influence language evolution. It presents examples of changes in the structure, function, and vitality of languages, suggesting that similar ecologies…

  7. Early Stages of the Evolution of Life: a Cybernetic Approach

    NASA Astrophysics Data System (ADS)

    Melkikh, Alexey V.; Seleznev, Vladimir D.

    2008-08-01

    Early stages of the evolution of life are considered in terms of control theory. A model is proposed for the transport of substances in a protocell possessing the property of robustness with regard to changes in the environmental concentration of a substance.

  8. Directed evolution as an approach to the design of efficient biocatalysts

    NASA Astrophysics Data System (ADS)

    Zagrebelny, Stanislav N.

    2005-03-01

    Methodical approaches to the modification of the catalytic properties of enzymes by various means of directed evolution are summarised. A number of particular examples of the design of enzymes with new and enhanced properties, including higher thermal stability, solubility, substrate specificity, stereoselectivity, etc., are considered. The prospects for further development of the directed evolution strategy for enzymes and proteins with other functions are discussed.

  9. Convergence of Galerkin approximations for operator Riccati equations: A nonlinear evolution equation approach

    NASA Technical Reports Server (NTRS)

    Rosen, I. G.

    1988-01-01

    An approximation and convergence theory was developed for Galerkin approximations to infinite dimensional operator Riccati differential equations formulated in the space of Hilbert-Schmidt operators on a separable Hilbert space. The Riccati equation was treated as a nonlinear evolution equation with dynamics described by a nonlinear monotone perturbation of a strongly coercive linear operator. A generic approximation result was proven for quasi-autonomous nonlinear evolution system involving accretive operators which was then used to demonstrate the Hilbert-Schmidt norm convergence of Galerkin approximations to the solution of the Riccati equation. The application of the results was illustrated in the context of a linear quadratic optimal control problem for a one dimensional heat equation.

  10. Predicting Thermal Conductivity Evolution of Polycrystalline Materials Under Irradiation Using Multiscale Approach

    SciTech Connect

    Li, Dongsheng; Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.

    2012-03-01

    A multiscale methodology was developed to predict the evolution of thermal conductivity of polycrystalline fuel under irradiation. In the mesoscale level, phase field model was used to predict the evolution of gas bubble microstructure. Generation of gas atoms and vacancies were taken into consideration. In the macroscopic scale, a statistical continuum mechanics model was applied to predict the anisotropic thermal conductivity evolution during irradiation. Microstructure predicted by phase field model was fed into statistical continuum mechanics model to predict properties and behavior. Influence of irradiation intensity, exposition time and morphology were investigated. This approach provides a deep understanding on microstructure evolution and property prediction from a basic scientific viewpoint.

  11. Approach of Complex-Systems Biology to Reproduction and Evolution

    NASA Astrophysics Data System (ADS)

    Kaneko, Kunihiko

    Two basic issues in biology - the origin of life and evolution of phenotypes - are discussed on the basis of statistical physics and dynamical systems. In section "A Bridge Between Catalytic Reaction Networks and Reproducing Cells", we survey recent developments in the origin of reproducing cells from an ensemble of catalytic reactions. After surveying several models of catalytic reaction networks briefly, we provide possible answers to the following three questions: (1) How are nonequilibrium states sustained in catalytic reaction dynamics? (2) How is recursive production of a cell maintaining composition of a variety of chemicals possible? (3) How does a specific molecule species carry information for heredity? In section "Evolution", general relationships between plasticity, robustness, and evolvability are presented in terms of phenotypic fluctuations. First, proportionality between evolution speed, phenotypic plasticity, and isogenic phenotypic fluctuation is proposed by extending the fluctuation-response relationship in physics. We then derive a general proportionality relationship between the phenotypic fluctuations of epigenetic and genetic origin: the former is the variance of phenotype due to noise in the developmental process, and the latter due to genetic mutation. The relationship also suggests a link between robustness to noise and to mutation. These relationships are confirmed in models of gene expression dynamics, as well as in laboratory experiments, and then are explained by a theory based on an evolutionary stability hypothesis For both sections "A Bridge Between Catalytic Reaction Networks and Reproducing Cells" and "Evolution", consistency between two levels of hierarchy (i.e., molecular and cellular, or genetic and phenotypic levels) is stressed as a principle for complex-systems biology.

  12. A Quantitative Approach to Analyzing Genome Reductive Evolution Using Protein–Protein Interaction Networks: A Case Study of Mycobacterium leprae

    PubMed Central

    Akinola, Richard O.; Mazandu, Gaston K.; Mulder, Nicola J.

    2016-01-01

    The advance in high-throughput sequencing technologies has yielded complete genome sequences of several organisms, including complete bacterial genomes. The growing number of these available sequenced genomes has enabled analyses of their dynamics, as well as the molecular and evolutionary processes which these organisms are under. Comparative genomics of different bacterial genomes have highlighted their genome size and gene content in association with lifestyles and adaptation to various environments and have contributed to enhancing our understanding of the mechanisms of their evolution. Protein–protein functional interactions mediate many essential processes for maintaining the stability of the biological systems under changing environmental conditions. Thus, these interactions play crucial roles in the evolutionary processes of different organisms, especially for obligate intracellular bacteria, proven to generally have reduced genome sizes compared to their nearest free-living relatives. In this study, we used the approach based on the Renormalization Group (RG) analysis technique and the Maximum-Excluded-Mass-Burning (MEMB) model to investigate the evolutionary process of genome reduction in relation to the organization of functional networks of two organisms. Using a Mycobacterium leprae (MLP) network in comparison with a Mycobacterium tuberculosis (MTB) network as a case study, we show that reductive evolution in MLP was as a result of removal of important proteins from neighbors of corresponding orthologous MTB proteins. While each orthologous MTB protein had an increase in number of interacting partners in most instances, the corresponding MLP protein had lost some of them. This work provides a quantitative model for mapping reductive evolution and protein–protein functional interaction network organization in terms of roles played by different proteins in the network structure. PMID:27066064

  13. Evolution.

    ERIC Educational Resources Information Center

    Mayr, Ernst

    1978-01-01

    Traces the history of evolution theory from Lamarck and Darwin to the present. Discusses natural selection in detail. Suggests that, besides biological evolution, there is also a cultural evolution which is more rapid than the former. (MA)

  14. Protein Engineering by Combined Computational and In Vitro Evolution Approaches.

    PubMed

    Rosenfeld, Lior; Heyne, Michael; Shifman, Julia M; Papo, Niv

    2016-05-01

    Two alternative strategies are commonly used to study protein-protein interactions (PPIs) and to engineer protein-based inhibitors. In one approach, binders are selected experimentally from combinatorial libraries of protein mutants that are displayed on a cell surface. In the other approach, computational modeling is used to explore an astronomically large number of protein sequences to select a small number of sequences for experimental testing. While both approaches have some limitations, their combination produces superior results in various protein engineering applications. Such applications include the design of novel binders and inhibitors, the enhancement of affinity and specificity, and the mapping of binding epitopes. The combination of these approaches also aids in the understanding of the specificity profiles of various PPIs. PMID:27061494

  15. A Noisy 10GB Provenance Database

    SciTech Connect

    Cheah, You-Wei; Plale, Beth; Kendall-Morwick, Joey; Leake, David; Ramakrishnan, Lavanya

    2011-06-06

    Provenance of scientific data is a key piece of the metadata record for the data's ongoing discovery and reuse. Provenance collection systems capture provenance on the fly, however, the protocol between application and provenance tool may not be reliable. Consequently, the provenance record can be partial, partitioned, and simply inaccurate. We use a workflow emulator that models faults to construct a large 10GB database of provenance that we know is noisy (that is, has errors). We discuss the process of generating the provenance database, and show early results on the kinds of provenance analysis enabled by the large provenance.

  16. Computational Approaches to Viral Evolution and Rational Vaccine Design

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Tanmoy

    2006-10-01

    Viral pandemics, including HIV, are a major health concern across the world. Experimental techniques available today have uncovered a great wealth of information about how these viruses infect, grow, and cause disease; as well as how our body attempts to defend itself against them. Nevertheless, due to the high variability and fast evolution of many of these viruses, the traditional method of developing vaccines by presenting a heuristically chosen strain to the body fails and an effective intervention strategy still eludes us. A large amount of carefully curated genomic data on a number of these viruses are now available, often annotated with disease and immunological context. The availability of parallel computers has now made it possible to carry out a systematic analysis of this data within an evolutionary framework. I will describe, as an example, how computations on such data has allowed us to understand the origins and diversification of HIV, the causative agent of AIDS. On the practical side, computations on the same data is now being used to inform choice or defign of optimal vaccine strains.

  17. Random Matrix Approach to Quantum Adiabatic Evolution Algorithms

    NASA Technical Reports Server (NTRS)

    Boulatov, Alexei; Smelyanskiy, Vadier N.

    2004-01-01

    We analyze the power of quantum adiabatic evolution algorithms (Q-QA) for solving random NP-hard optimization problems within a theoretical framework based on the random matrix theory (RMT). We present two types of the driven RMT models. In the first model, the driving Hamiltonian is represented by Brownian motion in the matrix space. We use the Brownian motion model to obtain a description of multiple avoided crossing phenomena. We show that the failure mechanism of the QAA is due to the interaction of the ground state with the "cloud" formed by all the excited states, confirming that in the driven RMT models. the Landau-Zener mechanism of dissipation is not important. We show that the QAEA has a finite probability of success in a certain range of parameters. implying the polynomial complexity of the algorithm. The second model corresponds to the standard QAEA with the problem Hamiltonian taken from the Gaussian Unitary RMT ensemble (GUE). We show that the level dynamics in this model can be mapped onto the dynamics in the Brownian motion model. However, the driven RMT model always leads to the exponential complexity of the algorithm due to the presence of the long-range intertemporal correlations of the eigenvalues. Our results indicate that the weakness of effective transitions is the leading effect that can make the Markovian type QAEA successful.

  18. Random matrix approach to quantum adiabatic evolution algorithms

    SciTech Connect

    Boulatov, A.; Smelyanskiy, V.N.

    2005-05-15

    We analyze the power of the quantum adiabatic evolution algorithm (QAA) for solving random computationally hard optimization problems within a theoretical framework based on random matrix theory (RMT). We present two types of driven RMT models. In the first model, the driving Hamiltonian is represented by Brownian motion in the matrix space. We use the Brownian motion model to obtain a description of multiple avoided crossing phenomena. We show that nonadiabatic corrections in the QAA are due to the interaction of the ground state with the 'cloud' formed by most of the excited states, confirming that in driven RMT models, the Landau-Zener scenario of pairwise level repulsions is not relevant for the description of nonadiabatic corrections. We show that the QAA has a finite probability of success in a certain range of parameters, implying a polynomial complexity of the algorithm. The second model corresponds to the standard QAA with the problem Hamiltonian taken from the RMT Gaussian unitary ensemble (GUE). We show that the level dynamics in this model can be mapped onto the dynamics in the Brownian motion model. For this reason, the driven GUE model can also lead to polynomial complexity of the QAA. The main contribution to the failure probability of the QAA comes from the nonadiabatic corrections to the eigenstates, which only depend on the absolute values of the transition amplitudes. Due to the mapping between the two models, these absolute values are the same in both cases. Our results indicate that this 'phase irrelevance' is the leading effect that can make both the Markovian- and GUE-type QAAs successful.

  19. Bridging Inter- and Intraspecific Trait Evolution with a Hierarchical Bayesian Approach.

    PubMed

    Kostikova, Anna; Silvestro, Daniele; Pearman, Peter B; Salamin, Nicolas

    2016-05-01

    The evolution of organisms is crucially dependent on the evolution of intraspecific variation. Its interactions with selective agents in the biotic and abiotic environments underlie many processes, such as intraspecific competition, resource partitioning and, eventually, species formation. Nevertheless, comparative models of trait evolution neither allow explicit testing of hypotheses related to the evolution of intraspecific variation nor do they simultaneously estimate rates of trait evolution by accounting for both trait mean and variance. Here, we present a model of phenotypic trait evolution using a hierarchical Bayesian approach that simultaneously incorporates interspecific and intraspecific variation. We assume that species-specific trait means evolve under a simple Brownian motion process, whereas species-specific trait variances are modeled with Brownian or Ornstein-Uhlenbeck processes. After evaluating the power of the method through simulations, we examine whether life-history traits impact evolution of intraspecific variation in the Eriogonoideae (buckwheat family, Polygonaceae). Our model is readily extendible to more complex scenarios of the evolution of inter- and intraspecific variation and presents a step toward more comprehensive comparative models for macroevolutionary studies. PMID:26911152

  20. Scapular dyskinesia: evolution towards a systems-based approach.

    PubMed

    Willmore, Elaine G; Smith, Michael J

    2016-01-01

    Historically, scapular dyskinesia has been used to describe an isolated clinical entity whereby an abnormality in positioning, movement or function of the scapula is present. Based upon this, treatment approaches have focused on addressing local isolated muscle activity. Recently, however, there has been a progressive move towards viewing the scapula as being part of a wider system of movement that is regulated and controlled by multiple factors, including the wider kinetic chain and individual patient-centred requirements. We therefore propose a paradigm shift whereby scapular dyskinesia is seen not in isolation but is considered within the broader context of patient-centred care and an entire neuromuscular system. PMID:27583003

  1. An ensemble approach to the evolution of complex systems.

    PubMed

    Arpağ, Göker; Erzan, Ayşe

    2014-04-01

    Adaptive systems frequently incorporate complex structures which can arise spontaneously and which may be nonadaptive in the evolutionary sense. We give examples from phase transition and fractal growth to develop the themes of cooperative phenomena and pattern formation. We discuss RNA interference and transcriptional gene regulation networks, where a major part of the topological properties can be accounted for by mere combinatorics. A discussion of ensemble approaches to biological systems and measures of complexity is presented, and a connection is established between complexity and fitness. PMID:24736159

  2. Scapular dyskinesia: evolution towards a systems-based approach

    PubMed Central

    Smith, Michael J

    2015-01-01

    Historically, scapular dyskinesia has been used to describe an isolated clinical entity whereby an abnormality in positioning, movement or function of the scapula is present. Based upon this, treatment approaches have focused on addressing local isolated muscle activity. Recently, however, there has been a progressive move towards viewing the scapula as being part of a wider system of movement that is regulated and controlled by multiple factors, including the wider kinetic chain and individual patient-centred requirements. We therefore propose a paradigm shift whereby scapular dyskinesia is seen not in isolation but is considered within the broader context of patient-centred care and an entire neuromuscular system. PMID:27583003

  3. PAV ontology: provenance, authoring and versioning

    PubMed Central

    2013-01-01

    We analyze and compare PAV with related approaches, namely Provenance Vocabulary (PRV), DC Terms and BIBFRAME. We identify similarities and analyze differences between those vocabularies and PAV, outlining strengths and weaknesses of our proposed model. We specify SKOS mappings that align PAV with DC Terms. We conclude the paper with general remarks on the applicability of PAV. PMID:24267948

  4. Adaptive virulence evolution: the good old fitness-based approach.

    PubMed

    Alizon, Samuel; Michalakis, Yannis

    2015-05-01

    Infectious diseases could be expected to evolve towards complete avirulence to their hosts if given enough time. However, this is not the case. Often, virulence is maintained because it is linked to adaptive advantages to the parasite, a situation that is often associated with the hypothesis known as the transmission-virulence trade-off hypothesis. Here, we argue that this hypothesis has three limitations, which are related to how virulence is defined, the possibility of multiple trade-offs, and the difficulty of testing the hypothesis empirically. By adopting a fitness-based approach, where the relation between virulence and the fitness of the parasite throughout its life cycle is directly assessed, it is possible to address these limitations and to determine directly whether virulence is adaptive. PMID:25837917

  5. A variational approach to understanding white dwarf evolution

    NASA Technical Reports Server (NTRS)

    Wood, M. A.; Winget, D. E.

    1989-01-01

    A variational approach is used to map out the effects that uncertainties in the theoretical model parameters have upon the derived ages near the observed cutoff in the white dwarf luminosity function. Two representative sequences are assessed, simulating a white dwarf with a 50/50 C/O mixture in the core and an outer helium layer and a white dwarf with a C/O convective overshooting profile. The differential effects that the variation of selected model input quantities has on the ages are reported, and it is concluded that internal theoretical uncertainties are small and getting smaller with time, and the results underscore the power of using the observed white dwarf luminosity function for studying the history of star formation in the Galaxy.

  6. Evolution of Minimally Invasive Approaches to the Sella and Parasellar Region

    PubMed Central

    Louis, Robert G.; Eisenberg, Amy; Barkhoudarian, Garni; Griffiths, Chester; Kelly, Daniel F.

    2014-01-01

    Introduction Given advancements in endoscopic image quality, instrumentation, surgical navigation, skull base closure techniques, and anatomical understanding, the endonasal endoscopic approach has rapidly evolved into a widely utilized technique for removal of sellar and parasellar tumors. Although pituitary adenomas and Rathke cleft cysts constitute the majority of lesions removed via this route, craniopharyngiomas, clival chordomas, parasellar meningiomas, and other lesions are increasingly removed using this approach. Paralleling the evolution of the endonasal route to the parasellar region, the supraorbital eyebrow craniotomy has also been increasingly used as an alternative minimally invasive approach to reach this skull base region. Similar to the endonasal route, the supraorbital route has been greatly facilitated by advances in endoscopy, along with development of more refined, low-profile instrumentation and surgical navigation technology. Objectives This review, encompassing both transcranial and transsphenoidal routes, will recount the high points and advances that have made minimally invasive approaches to the sellar region possible, the evolution of these approaches, and their relative indications and technical nuances. Data Synthesis The literature is reviewed regarding the evolution of surgical approaches to the sellar region beginning with the earliest attempts and emphasizing technological advances, which have allowed the evolution of the modern technique. The surgical techniques for both endoscopic transsphenoidal and supraorbital approaches are described in detail. The relative indications for each approach are highlighted using case illustrations. Conclusions Although tremendous advances have been made in transitioning toward minimally invasive transcranial and transsphenoidal approaches to the sella, further work remains to be done. Together, the endonasal endoscopic and the supraorbital endoscope-assisted approaches are complementary

  7. Continuing evolution in the approach to severe liver trauma.

    PubMed Central

    Reed, R L; Merrell, R C; Meyers, W C; Fischer, R P

    1992-01-01

    Surgical and radiologic techniques from computed tomography (CT) scanning and embolization to temporary gauze packing and mesh hepatorrhaphy have been developed to make the management of severe liver injuries more effective. Surgical approaches for severe liver trauma have been oriented to two major consequences of these injuries: hemorrhage and infection. Early attempts at hemorrhagic control found benefit only in temporary intrahepatic gauze packing. The subsequent recognition of complications after liver injury blamed the practice of packing, which then remained unused for more than 30 years. Yet more aggressive attempts at controlling hemorrhage without temporary packing failed to improve results. Temporary perihepatic gauze packing therefore has been reintroduced, but this is probably an imperfect solution. Mesh hepatorrhaphy may control bleeding without many of the adverse effects of packing. Fourteen patients are reported with severe liver injuries who have undergone mesh hepatorrhaphy, bringing the current reported experience with mesh hepatorrhaphy to 24, with a combined mortality rate of 37.5%. Thus far, it appears that only juxtacaval injuries fail to have their hemorrhage controlled with mesh hepatorrhaphy, but many believe that these injuries may be controlled by perihepatic packing. Prophylactic drainage of severe liver injuries is a concept for which there is little evidence of benefit. Furthermore, recent radiologic developments appear capable of draining those collections that do occasionally develop in the postoperative period. The ultimate challenge of liver transplantation for trauma has been attempted, but the experience is thus far very limited. PMID:1444644

  8. Surge-tectonic evolution of southeastern Asia: a geohydrodynamics approach

    NASA Astrophysics Data System (ADS)

    Meyerhoff, Arthur A.

    The repeated need for ad hoc modifications in plate-tectonic models to explain the evolution of southeastern Asia reveals their inability to fully explain the complex features and dynamics of this region. As one example, the hypothesis does not provide a mechanism to explain the 180° turns and twists along the strike of several foldbelts and island arcs in the region (e.g. Banda arc). Convection-cell configuration renders such 180° contortions and Rayleigh-Bénard-type convection impossible. However, during the last 10 years, new data bearing on the convection-cell problem have become available in the form of seismotomographic images of the earth's interior. These images show that (i) mantle diapirs as proposed by traditional plate-tectonic models do not exist; (ii) there is no discernible pattern of upper or lower mantle convection, and thus no longer an adequate mechanism to move plates; and (iii) the lithosphere above a depth of about 80 km is permeated by an interconnected network of low-velocity channels. Seismic-reflection studies of the low-velocity channels discovered on the seismotomographic images reveal that these channels have walls with a 7.1-7.8 km s -1 P-wave velocity. Commonly, the interiors of the channels are acoustically transparent, with much slower P-wave velocities, in places as low as 5.4 km s -1. The author and co-workers have interpreted the low velocities as evidence for the presence of partial melt in the channels, and they postulated that this melt moves preferentially eastward as a result of the earth's rotation. They named these channels "surge channels" and their new hypothesis for earth dynamics "surge tectonics". Surge channels underlie every type of tectonic belt, which includes mid-ocean ridges, aseismic ridges, continental rifts, strike-slip fracture zones, and foldbelts. In southeastern Asia, surge channels—mainly foldbelts—lie between all platform and cratonic massifs. These massifs, platforms, and tectonics belts

  9. Surge-tectonic evolution of southeastern Asia: a geohydrodynamics approach

    NASA Astrophysics Data System (ADS)

    Meyerhoff, Arthur A.

    The repeated need for ad hoc modifications in plate-tectonic models to explain the evolution of southeastern Asia reveals their inability to fully explain the complex features and dynamics of this region. As one example, the hypothesis does not provide a mechanism to explain the 180° turns and twists along the strike of several foldbelts and island arcs in the region (e.g. Banda arc). Convection-cell configuration renders such 180° contortions and Rayleigh-Bénard-type convection impossible. However, during the last 10 years, new data bearing on the convection-cell problem have become available in the form of seismotomographic images of the earth's interior. These images show that (i) mantle diapirs as proposed by traditional plate-tectonic models do not exist; (ii) there is no discernible pattern of upper or lower mantle convection, and thus no longer an adequate mechanism to move plates; and (iii) the lithosphere above a depth of about 80 km is permeated by an interconnected network of low-velocity channels. Seismic-reflection studies of the low-velocity channels discovered on the seismotomographic images reveal that these channels have walls with a 7.1-7.8 km s -1 P-wave velocity. Commonly, the interiors of the channels are acoustically transparent, with much slower P-wave velocities, in places as low as 5.4 km s -1. The author and co-workers have interpreted the low velocities as evidence for the presence of partial melt in the channels, and they postulated that this melt moves preferentially eastward as a result of the earth's rotation. They named these channels "surge channels" and their new hypothesis for earth dynamics "surge tectonics". Surge channels underlie every type of tectonic belt, which includes mid-ocean ridges, aseismic ridges, continental rifts, strike-slip fracture zones, and foldbelts. In southeastern Asia, surge channels—mainly foldbelts—lie between all platform and cratonic massifs. These massifs, platforms, and tectonics belts

  10. Objective 3D face recognition: Evolution, approaches and challenges.

    PubMed

    Smeets, Dirk; Claes, Peter; Vandermeulen, Dirk; Clement, John Gerald

    2010-09-10

    Face recognition is a natural human ability and a widely accepted identification and authentication method. In modern legal settings, a lot of credence is placed on identifications made by eyewitnesses. Consequently these are based on human perception which is often flawed and can lead to situations where identity is disputed. Therefore, there is a clear need to secure identifications in an objective way based on anthropometric measures. Anthropometry has existed for many years and has evolved with each advent of new technology and computing power. As a result of this, face recognition methodology has shifted from a purely 2D image-based approach to the use of 3D facial shape. However, one of the main challenges still remaining is the non-rigid structure of the face, which can change permanently over varying time-scales and briefly with facial expressions. The majority of face recognition methods have been developed by scientists with a very technical background such as biometry, pattern recognition and computer vision. This article strives to bridge the gap between these communities and the forensic science end-users. A concise review of face recognition using 3D shape is given. Methods using 3D shape applied to data embodying facial expressions are tabulated for reference. From this list a categorization of different strategies to deal with expressions is presented. The underlying concepts and practical issues relating to the application of each strategy are given, without going into technical details. The discussion clearly articulates the justification to establish archival, reference databases to compare and evaluate different strategies. PMID:20395086

  11. Provenance management in Swift with implementation details.

    SciTech Connect

    Gadelha, L. M. R; Clifford, B.; Mattoso, M.; Wilde, M.; Foster, I.

    2011-04-01

    The Swift parallel scripting language allows for the specification, execution and analysis of large-scale computations in parallel and distributed environments. It incorporates a data model for recording and querying provenance information. In this article we describe these capabilities and evaluate interoperability with other systems through the use of the Open Provenance Model. We describe Swift's provenance data model and compare it to the Open Provenance Model. We also describe and evaluate activities performed within the Third Provenance Challenge, which consisted of implementing a specific scientific workflow, capturing and recording provenance information of its execution, performing provenance queries, and exchanging provenance information with other systems. Finally, we propose improvements to both the Open Provenance Model and Swift's provenance system.

  12. The Natural Selection: Identifying Student Misconceptions through an Inquiry-Based, Critical Approach to Evolution

    ERIC Educational Resources Information Center

    Robbins, Jennifer R.; Roy, Pamela

    2007-01-01

    We invited 141 non-science major undergraduates to share and then challenge their preconceptions about evolution in a four-lesson inquiry lab unit that integrated diverse topics with rigorous assessment. Our experience suggests that an inquiring approach to evolutionary theory can be highly persuasive.

  13. File level provenance tracking in CMS

    SciTech Connect

    Jones, C.D.; Kowalkowski, J.; Paterno, M.; Sexton-Kennedy, L.; Tanenbaum, W.; Riley, D.S.; /Cornell U., LEPP

    2009-05-01

    The CMS off-line framework stores provenance information within CMS's standard ROOT event data files. The provenance information is used to track how each data product was constructed, including what other data products were read to do the construction. We will present how the framework gathers the provenance information, the efforts necessary to minimize the space used to store the provenance in the file and the tools that will be available to use the provenance.

  14. Detrital zircon record of Paleozoic and Mesozoic meta-sedimentary strata in the eastern part of the Baoshan block: Implications of their provenance and the tectonic evolution of the southeastern margin of the Tibetan plateau

    NASA Astrophysics Data System (ADS)

    Li, Dapeng; Chen, Yuelong; Hou, Kejun; Lu, Zhen; Cui, Di

    2015-06-01

    The Baoshan block is one of the important members in the southeastern margin of the Tibetan Plateau. Cambrian to Jurassic (meta-) sedimentary strata and their metamorphic counterparts were well preserved in the eastern part of the Baoshan block. Zircon U-Pb dating, trace elements, and Hf isotope data for both the Cambrian to Jurassic (meta-) sedimentary sequences and the Lincang granite were used to deduce the provenance of sediments and crustal affinity with eastern Gondwanaland. The Lincang granite outcropped in the Fengqing area is typical S-type, with crystallization age of ~ 230 Ma and narrow range of zircon εHf(t) values from - 15.5 to - 10. Detrital zircons from Paleozoic strata range in age from Archean to early Paleozoic, with age peaks at ~ 2.5, ~ 0.95, and ~ 0.6 Ga. Triassic age peak (~ 230 Ma) was also detected in the Jurassic strata. Detrital zircon εHf(t) values exhibit a wide range from negative to positive for each of the four major age groups, showing the host magma of zircons from these groups have diverse sources. The Baoshan block should be along the Indian margin as the Qiangtang, Tengchong and Simao-Indochina blocks in Early Paleozoic based on the provenance analyses. Sediment inputs eroded from both the Lincang granite and the coeval igneous rocks in the Baoshan and Gongshan blocks were the dominant contributions to the Jurassic strata after the amalgation of the Baoshan and Simao-Indochina blocks. Tectonic processes linking dispersion of the Baoshan-Sibumasu terrane from the Gondwana supercontinent to the collision with the Simao-Indochina block and the deposition of the Cambrian to Jurassic sedimentary sequences were reconstructed.

  15. Comparative genetic approaches to the evolution of human brain and behavior

    PubMed Central

    Vallender, Eric J.

    2012-01-01

    With advances in genomic technologies the amount of genetic data available to scientists today is vast. Genomes are now available or planned for fourteen different primate species and complete resequencing of numerous human individuals from numerous populations is underway. Moreover, high-throughput deep sequencing is quickly making whole genome efforts within the reach of single laboratories allowing for unprecedented studies. Comparative genetic approaches to the identification of the underlying basis of human brain, behavior and cognitive ability are moving to the forefront. Two approaches predominate: inter-species divergence comparisons and intra-species polymorphism studies. These methodological differences are useful for different time scales of evolution and necessarily focus on different evolutionary events in the history of primate and hominin evolution. Inter-species divergence is more useful in studying large scale primate, or hominoid, evolution whereas intra-species polymorphism can be more illuminating of recent hominin evolution. These differences in methodological utility also extend to studies of differing genetic substrates; current divergence studies focus primarily on protein evolution while polymorphism studies are substrate ambivalent. Some of the issues inherent in these studies can be ameliorated by current sequencing capabilities while others remain intractable. New avenues are also being opened that allow for the incorporation of novel substrates and approaches. In the post-genomic era the study of human evolution, specifically as it relates to the brain, is becoming more complete focusing increasingly on the totality of the system and better conceptualizing the entirety of the genetic changes that have lead to the human phenotype today. PMID:21140466

  16. Transzygomatic Approach to Skull Base: History, Evolution, and Possibility of a Simple Modification.

    PubMed

    Badwal, Jaspreet Singh

    2016-05-01

    The surgical approaches to anterior, middle, and lateral skull base have evolved drastically, transcending from an era of oblivion to well-defined and systematically executed, state-of-the-art, refined surgery. The transzygomatic approach, which was developed to access the nasopharynx, has been applied to versatile locations of skull base pathology, with continuous evolution and modification of the osteotomies and skin flaps involved. A simple modification is proposed which could help reach a compromise between the wide exposure provided by the hemicoronal incision and the minimally invasive preauricular approach. PMID:27054426

  17. Launch Services, a Proven Model

    NASA Astrophysics Data System (ADS)

    Trafton, W. C.; Simpson, J.

    2002-01-01

    From a commercial perspective, the ability to justify "leap frog" technology such as reusable systems has been difficult to justify because the estimated 5B to 10B investment is not supported in the current flat commercial market coupled with an oversupply of launch service suppliers. The market simply does not justify investment of that magnitude. Currently, next generation Expendable Launch Systems, including Boeing's Delta IV, Lockheed Martin's Atlas 5, Ariane V ESCA and RSC's H-IIA are being introduced into operations signifying that only upgrades to proven systems are planned to meet the changes in anticipated satellite demand (larger satellites, more lifetime, larger volumes, etc.) in the foreseeable future. We do not see a new fleet of ELVs emerging beyond that which is currently being introduced, only continuous upgrades of the fleet to meet the demands. To induce a radical change in the provision of launch services, a Multinational Government investment must be made and justified by World requirements. The commercial market alone cannot justify such an investment. And if an investment is made, we cannot afford to repeat previous mistakes by relying on one system such as shuttle for commercial deployment without having any back-up capability. Other issues that need to be considered are national science and security requirements, which to a large extent fuels the Japanese, Chinese, Indian, Former Soviet Union, European and United States space transportation entries. Additionally, this system must support or replace current Space Transportation Economies with across-the-board benefits. For the next 10 to 20 years, Multinational cooperation will be in the form of piecing together launch components and infrastructure to supplement existing launch systems and reducing the amount of non-recurring investment while meeting the future requirements of the End-User. Virtually all of the current systems have some form of multinational participation: Sea Launch

  18. Evolution of transoral approaches, endoscopic endonasal approaches, and reduction strategies for treatment of craniovertebral junction pathology: a treatment algorithm update.

    PubMed

    Dlouhy, Brian J; Dahdaleh, Nader S; Menezes, Arnold H

    2015-04-01

    The craniovertebral junction (CVJ), or the craniocervical junction (CCJ) as it is otherwise known, houses the crossroads of the CNS and is composed of the occipital bone that surrounds the foramen magnum, the atlas vertebrae, the axis vertebrae, and their associated ligaments and musculature. The musculoskeletal organization of the CVJ is unique and complex, resulting in a wide range of congenital, developmental, and acquired pathology. The refinements of the transoral approach to the CVJ by the senior author (A.H.M.) in the late 1970s revolutionized the treatment of CVJ pathology. At the same time, a physiological approach to CVJ management was adopted at the University of Iowa Hospitals and Clinics in 1977 based on the stability and motion dynamics of the CVJ and the site of encroachment, incorporating the transoral approach for irreducible ventral CVJ pathology. Since then, approaches and techniques to treat ventral CVJ lesions have evolved. In the last 40 years at University of Iowa Hospitals and Clinics, multiple approaches to the CVJ have evolved and a better understanding of CVJ pathology has been established. In addition, new reduction strategies that have diminished the need to perform ventral decompressive approaches have been developed and implemented. In this era of surgical subspecialization, to properly treat complex CVJ pathology, the CVJ specialist must be trained in skull base transoral and endoscopic endonasal approaches, pediatric and adult CVJ spine surgery, and must understand and be able to treat the complex CSF dynamics present in CVJ pathology to provide the appropriate, optimal, and tailored treatment strategy for each individual patient, both child and adult. This is a comprehensive review of the history and evolution of the transoral approaches, extended transoral approaches, endoscopie assisted transoral approaches, endoscopie endonasal approaches, and CVJ reduction strategies. Incorporating these advancements, the authors update the

  19. An alternative approach for neural network evolution with a genetic algorithm: crossover by combinatorial optimization.

    PubMed

    García-Pedrajas, Nicolás; Ortiz-Boyer, Domingo; Hervás-Martínez, César

    2006-05-01

    In this work we present a new approach to crossover operator in the genetic evolution of neural networks. The most widely used evolutionary computation paradigm for neural network evolution is evolutionary programming. This paradigm is usually preferred due to the problems caused by the application of crossover to neural network evolution. However, crossover is the most innovative operator within the field of evolutionary computation. One of the most notorious problems with the application of crossover to neural networks is known as the permutation problem. This problem occurs due to the fact that the same network can be represented in a genetic coding by many different codifications. Our approach modifies the standard crossover operator taking into account the special features of the individuals to be mated. We present a new model for mating individuals that considers the structure of the hidden layer and redefines the crossover operator. As each hidden node represents a non-linear projection of the input variables, we approach the crossover as a problem on combinatorial optimization. We can formulate the problem as the extraction of a subset of near-optimal projections to create the hidden layer of the new network. This new approach is compared to a classical crossover in 25 real-world problems with an excellent performance. Moreover, the networks obtained are much smaller than those obtained with classical crossover operator. PMID:16343847

  20. Restful Implementation of Catalogue Service for Geospatial Data Provenance

    NASA Astrophysics Data System (ADS)

    Jiang, L. C.; Yue, P.; Lu, X. C.

    2013-10-01

    Provenance, also known as lineage, is important in understanding the derivation history of data products. Geospatial data provenance helps data consumers to evaluate the quality and reliability of geospatial data. In a service-oriented environment, where data are often consumed or produced by distributed services, provenance could be managed by following the same service-oriented paradigm. The Open Geospatial Consortium (OGC) Catalogue Service for the Web (CSW) is used for the registration and query of geospatial data provenance by extending ebXML Registry Information Model (ebRIM). Recent advance of the REpresentational State Transfer (REST) paradigm has shown great promise for the easy integration of distributed resources. RESTful Web Service aims to provide a standard way for Web clients to communicate with servers based on REST principles. The existing approach for provenance catalogue service could be improved by adopting the RESTful design. This paper presents the design and implementation of a catalogue service for geospatial data provenance following RESTful architecture style. A middleware named REST Converter is added on the top of the legacy catalogue service to support a RESTful style interface. The REST Converter is composed of a resource request dispatcher and six resource handlers. A prototype service is developed to demonstrate the applicability of the approach.

  1. Data Provenance in Photogrammetry Through Documentation Protocols

    NASA Astrophysics Data System (ADS)

    Carboni, N.; Bruseker, G.; Guillem, A.; Bellido Castañeda, D.; Coughenour, C.; Domajnko, M.; de Kramer, M.; Ramos Calles, M. M.; Stathopoulou, E. K.; Suma, R.

    2016-06-01

    Documenting the relevant aspects in digitisation processes such as photogrammetry in order to provide a robust provenance for their products continues to present a challenge. The creation of a product that can be re-used scientifically requires a framework for consistent, standardised documentation of the entire digitisation pipeline. This article provides an analysis of the problems inherent to such goals and presents a series of protocols to document the various steps of a photogrammetric workflow. We propose this pipeline, with descriptors to track all phases of digital product creation in order to assure data provenance and enable the validation of the operations from an analytic and production perspective. The approach aims to support adopters of the workflow to define procedures with a long term perspective. The conceptual schema we present is founded on an analysis of information and actor exchanges in the digitisation process. The metadata were defined through the synthesis of previous proposals in this area and were tested on a case study. We performed the digitisation of a set of cultural heritage artefacts from an Iron Age burial in Ilmendorf, Germany. The objects were captured and processed using different techniques, including a comparison of different imaging tools and algorithms. This augmented the complexity of the process allowing us to test the flexibility of the schema for documenting complex scenarios. Although we have only presented a photogrammetry digitisation scenario, we claim that our schema is easily applicable to a multitude of 3D documentation processes.

  2. Federated provenance of oceanographic research cruises: from metadata to data

    NASA Astrophysics Data System (ADS)

    Thomas, Rob; Leadbetter, Adam; Shepherd, Adam

    2016-04-01

    more formally in data journals. Use of the SPARQL 1.1 standard allows queries to be federated across these endpoints to create a distributed network of provenance documents. Future research directions will add further nodes to the federated network of oceanographic research cruise provenance to determine the true scalability of this approach, and will involve analysis of and possible evolution of the data release lifecycle ontology. References Nitin Arora et al., 2006. Information object design pattern for modeling domain specific knowledge. 1st ECOOP Workshop on Domain-Specific Program Development. Simon Cox, 2015. Pitfalls in alignment of observation models resolved using PROV as an upper ontology. Abstract IN33F-07 presented at the American Geophysical Union Fall Meeting, 14-18 December, San Francisco. Adam Leadbetter & Justin Buck, 2015. Where did my data layer come from?" The semantics of data release. Geophysical Research Abstracts 17, EGU2015-3746-1. Xiaogang Ma et al., 2014. Ontology engineering in provenance enablement for the National Climate Assessment. Environmental Modelling & Software 61, 191-205. http://dx.doi.org/10.1016/j.envsoft.2014.08.002

  3. [The cost of cancer in France: macroeconomic and microeconomic approaches, evolution towards a prospective payment system].

    PubMed

    Perrier, Lionel; Borella, Laurent; Philip, Thierry

    2003-11-01

    In this article we have reviewed the cost of cancer in France, based on a literature review. The cost of the treatment of cancer is estimated to be 10 thousand million euros for 75,000 lives saved annually. The increasing number of economic evaluations of cancer use both a macro economic approach, based on DRG data, and a micro economic approach, based on cost result analysis. These cost studies provide the elements for a decision aid in the context of social demands, budget constraints and the evolution towards a DRG's prospective payment system which characterises present organisation of health care in France. PMID:14706905

  4. Orbiting binary black hole evolutions with a multipatch high order finite-difference approach

    SciTech Connect

    Pazos, Enrique; Tiglio, Manuel; Duez, Matthew D.; Kidder, Lawrence E.; Teukolsky, Saul A.

    2009-07-15

    We present numerical simulations of orbiting black holes for around 12 cycles, using a high order multipatch approach. Unlike some other approaches, the computational speed scales almost perfectly for thousands of processors. Multipatch methods are an alternative to adaptive mesh refinement, with benefits of simplicity and better scaling for improving the resolution in the wave zone. The results presented here pave the way for multipatch evolutions of black hole-neutron star and neutron star-neutron star binaries, where high resolution grids are needed to resolve details of the matter flow.

  5. PROX: Approximated Summarization of Data Provenance

    PubMed Central

    Ainy, Eleanor; Bourhis, Pierre; Davidson, Susan B.; Deutch, Daniel; Milo, Tova

    2016-01-01

    Many modern applications involve collecting large amounts of data from multiple sources, and then aggregating and manipulating it in intricate ways. The complexity of such applications, combined with the size of the collected data, makes it difficult to understand the application logic and how information was derived. Data provenance has been proven helpful in this respect in different contexts; however, maintaining and presenting the full and exact provenance may be infeasible, due to its size and complex structure. For that reason, we introduce the notion of approximated summarized provenance, where we seek a compact representation of the provenance at the possible cost of information loss. Based on this notion, we have developed PROX, a system for the management, presentation and use of data provenance for complex applications. We propose to demonstrate PROX in the context of a movies rating crowd-sourcing system, letting participants view provenance summarization and use it to gain insights on the application and its underlying data. PMID:27570843

  6. Tracking Provenance in ORNL's Flexible Research Platforms

    SciTech Connect

    Hensley, Zachary P; Sanyal, Jibonananda; New, Joshua Ryan

    2013-08-01

    Provenance is dened as information about the origin of objects, a concept that applies to both physical and digital objects and often overlaps both. The use of provenance in systems designed for research is an important but forgotten feature. Provenance allows for proper and exact tracking of information, its use, its lineage, its derivations and other metadata that are important for correctly adhering to the scien- tic method. In our project's prescribed use of provenance, researchers can determine detailed information about the use of sensor data in their experiments on ORNL's Flexible Research Platforms (FRPs). Our project's provenance system, Provenance Data Management System (ProvDMS), tracks information starting with the creation of information by an FRP sensor. The system determines station information, sensor information, and sensor channel information. The system allows researchers to derive generations of experiments from the sensor data and tracks their hierarchical flow. Key points can be seen in the history of the information as part of the information's workflow. The concept of provenance and its usage in science is relatively new and while used in other cases around the world, our project's provenance diers in a key area. To keep track of provenance, most systems must be designed or redesigned around the new provenance system. Our system is designed as a cohesive but sepa- rate entity and allows for researchers to continue using their own methods of analysis without being constrained in their ways in order to track the provenance. We have designed ProvDMS using a lightweight provenance library, Core Provenance Library (CPL) v.6 In addition to keeping track of sensor data experiments and its provenance, ProvDMS also provides a web-enabled visualization of the inheritance.

  7. A comparison of directed evolution approaches using the beta-glucuronidase model system.

    PubMed

    Rowe, Lori A; Geddie, Melissa L; Alexander, Omar B; Matsumura, Ichiro

    2003-09-26

    Protein engineers can alter the properties of enzymes by directing their evolution in vitro. Many methods to generate molecular diversity and to identify improved clones have been developed, but experimental evolution remains as much an art as a science. We previously used DNA shuffling (sexual recombination) and a histochemical screen to direct the evolution of Escherichia coli beta-glucuronidase (GUS) variants with improved beta-galactosidase (BGAL) activity. Here, we employ the same model evolutionary system to test the efficiencies of several other techniques: recursive random mutagenesis (asexual), combinatorial cassette mutagenesis (high-frequency recombination) and a versatile high-throughput microplate screen. GUS variants with altered specificity evolved in each trial, but different combinations of mutagenesis and screening techniques effected the fixation of different beneficial mutations. The new microplate screen identified a broader set of mutations than the previously employed X-gal colony screen. Recursive random mutagenesis produced essentially asexual populations, within which beneficial mutations drove each other into extinction (clonal interference); DNA shuffling and combinatorial cassette mutagenesis led instead to the accumulation of beneficial mutations within a single allele. These results explain why recombinational approaches generally increase the efficiency of laboratory evolution. PMID:12972256

  8. Quantitative models of sediment generation and provenance: State of the art and future developments

    NASA Astrophysics Data System (ADS)

    Weltje, Gert Jan

    2012-12-01

    An overview of quantitative approaches to analysis and modelling of sediment generation and provenance is presented, with an emphasis on major framework components as determined by means of petrographic techniques. Conceptual models of sediment provenance are shown to be consistent with two classes of numerical-statistical models, i.e. linear mixing models and compositional linear models. These cannot be placed within a common mathematical framework, because the former requires that sediment composition is expressed in terms of proportions, whereas the latter requires that sediment composition is expressed in terms of log-ratios of proportions. Additivity of proportions, a fundamental assumption in linear mixing models, cannot be readily expressed in log-ratio terms. Linear mixing models may be used to describe compositional variability in terms of physical and conceptual (un)mixing. Models of physical (un)mixing are appropriate for describing compositional variation within transport-invariant subpopulations of grains as a result of varying rates of supply of detritus from multiple sources. Conceptual (un)mixing governs the relations among chemical, mineralogical and petrographic characteristics of sediments, which represent different descriptive levels within a compositional hierarchy. Compositional linear process models may be used to describe compositional and/or textural evolution resulting from selective modifications induced by sediment transport, as well as chemical and mechanical weathering. Current approaches to modelling of surface processes treat the coupled evolution of source areas and sedimentary basins in terms of bulk mass transfer only, and do not take into account compositional and textural sediment properties. Moving from the inverse modelling approach embodied in provenance research to process-based forward models of sediment generation which provide detailed predictions of sediment properties meets with considerable (albeit not insurmountable

  9. Evolution

    NASA Astrophysics Data System (ADS)

    Peter, Ulmschneider

    When we are looking for intelligent life outside the Earth, there is a fundamental question: Assuming that life has formed on an extraterrestrial planet, will it also develop toward intelligence? As this is hotly debated, we will now describe the development of life on Earth in more detail in order to show that there are good reasons why evolution should culminate in intelligent beings.

  10. Addressing controversies in science education: a pragmatic approach to evolution education

    NASA Astrophysics Data System (ADS)

    Hildebrand, David; Bilica, Kimberly; Capps, John

    2008-09-01

    Science education controversies typically prove more intractable than those in scientific research because they involve a wider range of considerations (e.g., epistemic, social, ethical, political, and religious). How can educators acknowledge central issues in a controversy (such as evolution)? How can such problems be addressed in a way that is ethically sensitive and intellectually responsible? Drawing in part on pragmatic philosopher John Dewey, our solution is politically proactive, philosophically pragmatic, and grounded in research. Central to our proposal is (1) steps toward creating a philosophical “total attitude” that is democratic, imaginative, and hypothetical; (2) a deeper understanding of how scientific theories can be pragmatically true; and (3) an assessment of differing pedagogical approaches for teaching evolution in the classroom.

  11. Distinguishing Provenance Equivalence of Earth Science Data

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt; Yesha, Ye; Halem, M.

    2010-01-01

    Reproducibility of scientific research relies on accurate and precise citation of data and the provenance of that data. Earth science data are often the result of applying complex data transformation and analysis workflows to vast quantities of data. Provenance information of data processing is used for a variety of purposes, including understanding the process and auditing as well as reproducibility. Certain provenance information is essential for producing scientifically equivalent data. Capturing and representing that provenance information and assigning identifiers suitable for precisely distinguishing data granules and datasets is needed for accurate comparisons. This paper discusses scientific equivalence and essential provenance for scientific reproducibility. We use the example of an operational earth science data processing system to illustrate the application of the technique of cascading digital signatures or hash chains to precisely identify sets of granules and as provenance equivalence identifiers to distinguish data made in an an equivalent manner.

  12. A differential evolution based approach for estimating minimal model parameters from IVGTT data.

    PubMed

    Ghosh, Subhojit

    2014-03-01

    Estimation of insulin sensitivity plays a crucial role in the diagnosis and clinical investigation of glucose related diseases. The Bergman minimal model provides a non-invasive approach for estimating insulin sensitivity from the glucose insulin time series data of intravenous glucose tolerance test (IVGTT). However, quite often in the traditional gradient based techniques for deriving insulin sensitivity from the minimal model, improper initialization leads to convergence problems and results in final solution, which are either incorrect or physiologically not feasible. This paper deals with a differential evolution-based approach for the determination of insulin sensitivity from the minimal model using clinical test data. Being a direct search based technique, the proposed approach enables the determination of the global solution irrespective of the initial parameter values. The fitting performance of the model with parameters estimated from the proposed approach is found to be higher than the corresponding model estimated from the widely used gradient based approach. A high correlation coefficient of 0.964 (95% confidence interval of [0.897,0.988]) is acheived between the estimated insulin sensitivity and the one obtained from the population based approach for 16 subjects. The high correlation signifies the relative similarity between the two estimated indices in representing the same physiological phenomena. The simulation results and statistical analysis reveal that the proposed technique provides a reliable estimate of insulin sensitivity with minimum prior knowledge. PMID:24529205

  13. Special Issue: The First Provenance Challenge

    SciTech Connect

    Moreau, Luc; Ludaescher, Bertram T.; Altintas, Ilkay; Barga, Roger S.; Bowers, Shawn; Callahan, Steven P.; Chin, George; Clifford, Ben; Cohen, Shirley; Cohen-Boulakia, Sarah; Davidson, Susan; Deelman, Ewa; digiampietri, Luciano; Foster, Ian T.; Freire, Juliana; Frew, James; Futrelle, Joe; Gibson, Tara D.; Gil, Yolanda; Goble, Carole; Golbeck, Jennifer; Groth, Paul; Holland, David A.; Jiang, Sheng; Kim, Jihie; Koop, David; Krenek, Ales; McPhillips, Timothy; Mehta, Gaurang; Miles, Simon; Metzger, Dominic; Munroe, Steve; Myers, James D.; Plale, Beth A.; Podhorszki, norbert; Ratnakar, Varun; Emanuele , Santos; scheidegger, Carlos E.; Schuchardt, Karen L.; Seltzer, Margo I.; Simmhan, Yogesh L.; Claudio, Silva T.; Slaughter, Peter; Stephan, Eric G.; Stevens, Robert; Turi, Daniele; Vo, Huy T.; Wilde, Mike J.; Zhao, Jun; Zhao, Yong

    2008-04-01

    The first Provenance Challenge was set up in order to provide a forum for the community to help understand the capabilities of different provenance systems and the expressiveness of their provenance representations. To this end, a Functional Magnetic Resonance Imaging workflow was defined, which participants had to either simulate or run in order to produce some provenance representation, from which a set of identified queries had to be implemented and executed. Sixteen teams responded to the challenge, and submitted their inputs. In this paper, we present the challenge workflow and queries, and summarise the participants contributions.

  14. Dhat syndrome: Evolution of concept, current understanding, and need of an integrated approach

    PubMed Central

    Kar, Sujita Kumar; Sarkar, Siddharth

    2015-01-01

    Dhat syndrome has often been construed as a culture-bound sexual neurosis of the Indian subcontinent. Symptoms similar to that of Dhat syndrome has been described in other cultures across different time periods. The present paper looks at the evolution of the concept of Dhat syndrome in India. The review also takes an overview of the current understanding of this syndrome in terms of nosological status as a distinct entity and its “culture-bound” status. The narrative finally attempts to discuss the integrated approach for the treatment of this disorder. PMID:26538854

  15. Shape evolution and collective dynamics of quasifission in the time-dependent Hartree-Fock approach

    NASA Astrophysics Data System (ADS)

    Umar, A. S.; Oberacker, V. E.; Simenel, C.

    2015-08-01

    Background: At energies near the Coulomb barrier, capture reactions in heavy-ion collisions result either in fusion or in quasifission. The former produces a compound nucleus in statistical equilibrium, while the second leads to a reseparation of the fragments after partial mass equilibration without formation of a compound nucleus. Extracting the compound nucleus formation probability is crucial to predict superheavy-element formation cross sections. It requires a good knowledge of the fragment angular distribution which itself depends on quantities such as moments of inertia and excitation energies which have so far been somewhat arbitrary for the quasifission contribution. Purpose: Our main goal is to utilize the time-dependent Hartee-Fock (TDHF) approach to extract ingredients of the formula used in the analysis of experimental angular distributions. These include the moment-of-inertia and temperature. Methods: We investigate the evolution of the nuclear density in TDHF calculations leading to quasifission. We study the dependence of the relevant quantities on various initial conditions of the reaction process. Results: The evolution of the moment of inertia is clearly nontrivial and depends strongly on the characteristics of the collision. The temperature rises quickly when the kinetic energy is transformed into internal excitation. Then, it rises slowly during mass transfer. Conclusions: Fully microscopic theories are useful to predict the complex evolution of quantities required in macroscopic models of quasifission.

  16. Effects of Extrinsic Mortality on the Evolution of Aging: A Stochastic Modeling Approach

    PubMed Central

    Shokhirev, Maxim Nikolaievich; Johnson, Adiv Adam

    2014-01-01

    The evolutionary theories of aging are useful for gaining insights into the complex mechanisms underlying senescence. Classical theories argue that high levels of extrinsic mortality should select for the evolution of shorter lifespans and earlier peak fertility. Non-classical theories, in contrast, posit that an increase in extrinsic mortality could select for the evolution of longer lifespans. Although numerous studies support the classical paradigm, recent data challenge classical predictions, finding that high extrinsic mortality can select for the evolution of longer lifespans. To further elucidate the role of extrinsic mortality in the evolution of aging, we implemented a stochastic, agent-based, computational model. We used a simulated annealing optimization approach to predict which model parameters predispose populations to evolve longer or shorter lifespans in response to increased levels of predation. We report that longer lifespans evolved in the presence of rising predation if the cost of mating is relatively high and if energy is available in excess. Conversely, we found that dramatically shorter lifespans evolved when mating costs were relatively low and food was relatively scarce. We also analyzed the effects of increased predation on various parameters related to density dependence and energy allocation. Longer and shorter lifespans were accompanied by increased and decreased investments of energy into somatic maintenance, respectively. Similarly, earlier and later maturation ages were accompanied by increased and decreased energetic investments into early fecundity, respectively. Higher predation significantly decreased the total population size, enlarged the shared resource pool, and redistributed energy reserves for mature individuals. These results both corroborate and refine classical predictions, demonstrating a population-level trade-off between longevity and fecundity and identifying conditions that produce both classical and non

  17. Bedform genesis and evolution in bedrock substrates: a new experimental approach

    NASA Astrophysics Data System (ADS)

    Parsons, D. R.; Yin, N.; Peakall, J.

    2014-12-01

    Most previous studies on the genesis and evolution of bedforms have focused on aggradational bedforms within cohesionless sediments, with very few investigations that concern either erosive bedform genesis and evolution or bedrock channel abrasion processes. The study presented here details experiments that involve the genesis and formation of erosional bedform features within natural (soft clay) cohesive sediment beds and analogue bedrock substrates by modelling clay under the effect of both open-channel plain water flows, and sediment-laden flows. A new approach without using plaster-of-Paris or real bedrock developed provides a feasible method to simulate the genesis and evolution of the erosional bedforms in cohesive sediment beds and sculpted forms in bedrock channels on relatively short time-scales in the laboratory by using a realistic substrate substitute.A series of flume experiments are presented herein where the undrained shear strength of two different kinds of substrate material is systematically varied under constant flow conditions. Experiments using plain water flow indicated that erosive bedforms in cohesive sediment substrate cannot be produced only under the effect of sediment-free flow. Particulate-laden flows do form erosional bedforms in both kinds of clay beds and the shear strength of the bed material plays a key role in determining the diversity of erosional features forming on such substrates. Optimisation of modelling clay beds has enabled us to successfully replicate a suite of bedrock bedforms, including potholes, flutes, longitudinal furrows, etc., that have clear equivalents to those observed in bedrock rivers and contributed to investigate the genesis and evolution process of them and explore the flow structures within and above them in experimental analogue bedrock substrate for the first time.

  18. General-relativistic approach to the nonlinear evolution of collisionless matter

    SciTech Connect

    Matarrese, S.; Pantano, O. ); Saez, D. )

    1993-02-15

    A new general-relativistic algorithm is developed to study the nonlinear evolution of scalar (density) perturbations of an irrotational collisionless fluid up to shell crossing, under the approximation of neglecting the interaction with tensor (gravitational-wave) perturbations. The dynamics of each fluid element is separately followed in its own inertial rest frame by a system of twelve coupled first-order ordinary differential equations, which can be further reduced to six under very general conditions. Initial conditions are obtained in a cosmological framework, from linear theory, in terms of a single gauge-invariant potential. Physical observables, which are expressed in the Lagrangian form at different times, can be traced back to the Eulerian picture by solving supplementary first-order differential equations for the relative position vectors of neighboring fluid elements. Similarly to the Zel'dovich approximation, in our approach the evolution of each fluid element is completely determined by the local initial conditions and can be independently followed up to the time when it enters a multistream region. Unlike the Zel'dovich approximation, however, our approach is correct also in three dimensions (except for the possible role of gravitational waves). The accuracy of our numerical procedure is tested by integrating the nonlinear evolution of a spherical perturbation in an otherwise spatially flat Friedmann-Robertson-Walker universe and comparing the results with the exact Tolman-Bondi solution for the same initial profile. An exact solution for the planar symmetric case is also given, which turns out to be locally identical to the Zel'dovich solution.

  19. The floral morphospace--a modern comparative approach to study angiosperm evolution.

    PubMed

    Chartier, Marion; Jabbour, Florian; Gerber, Sylvain; Mitteroecker, Philipp; Sauquet, Hervé; von Balthazar, Maria; Staedler, Yannick; Crane, Peter R; Schönenberger, Jürg

    2014-12-01

    Morphospaces are mathematical representations used for studying the evolution of morphological diversity and for the evaluation of evolved shapes among theoretically possible ones. Although widely used in zoology, they--with few exceptions--have been disregarded in plant science and in particular in the study of broad-scale patterns of floral structure and evolution. Here we provide basic information on the morphospace approach; we review earlier morphospace applications in plant science; and as a practical example, we construct and analyze a floral morphospace. Morphospaces are usually visualized with the help of ordination methods such as principal component analysis (PCA) or nonmetric multidimensional scaling (NMDS). The results of these analyses are then coupled with disparity indices that describe the spread of taxa in the space. We discuss these methods and apply modern statistical tools to the first and only angiosperm-wide floral morphospace published by Stebbins in 1951. Despite the incompleteness of Stebbins’ original dataset, our analyses highlight major, angiosperm-wide trends in the diversity of flower morphology and thereby demonstrate the power of this previously neglected approach in plant science. PMID:25539005

  20. A combined NLP-differential evolution algorithm approach for the optimization of looped water distribution systems

    NASA Astrophysics Data System (ADS)

    Zheng, Feifei; Simpson, Angus R.; Zecchin, Aaron C.

    2011-08-01

    This paper proposes a novel optimization approach for the least cost design of looped water distribution systems (WDSs). Three distinct steps are involved in the proposed optimization approach. In the first step, the shortest-distance tree within the looped network is identified using the Dijkstra graph theory algorithm, for which an extension is proposed to find the shortest-distance tree for multisource WDSs. In the second step, a nonlinear programming (NLP) solver is employed to optimize the pipe diameters for the shortest-distance tree (chords of the shortest-distance tree are allocated the minimum allowable pipe sizes). Finally, in the third step, the original looped water network is optimized using a differential evolution (DE) algorithm seeded with diameters in the proximity of the continuous pipe sizes obtained in step two. As such, the proposed optimization approach combines the traditional deterministic optimization technique of NLP with the emerging evolutionary algorithm DE via the proposed network decomposition. The proposed methodology has been tested on four looped WDSs with the number of decision variables ranging from 21 to 454. Results obtained show the proposed approach is able to find optimal solutions with significantly less computational effort than other optimization techniques.

  1. Evolution of Organic Aerosols in the Atmosphere: A Synthesis of Emerging Approaches

    NASA Astrophysics Data System (ADS)

    Canagaratna, Manjula R.; Jimenez, J. L.; Donahue, N. M.; Kroll, J. H.; Heald, C. L.; Cappa, C. D.; Prevot, A. S. H.; Worsnop, D. R.; Ng, N. L.; AMS Oa Evolution Team

    2010-05-01

    Organic aerosol (OA) particles affect climate forcing and human health, but their sources and evolution remain poorly characterized. In this presentation we will summarize several emerging approaches to describe the atmospheric evolution of OA that are constrained by high-time-resolution measurements of their composition, volatility, and oxidation state, including and building on the recent Jimenez et al. paper (Science, Dec. 2009). OA and OA-precursor gases evolve by becoming increasingly oxidized, less volatile, and more hygroscopic, leading to the formation of oxygenated organic aerosol (OOA) mass with concentrations comparable to sulfate aerosol throughout the Northern Hemisphere. We identify two types of OOA, semivolatile OOA (SV-OOA) and low-volatility OOA (LV-OOA), with LV-OOA being more aged and hygroscopic. LV-OOA is effectively non-volatile and will not return to the gas-phase under any plausible atmospheric conditions (Cappa et al., ACPD, 2010). The evolution of ambient OOA can be captured in a 2-dimensional diagram based on AMS fragments; chamber SOA mostly falls in the same region of the diagram but does not reach the levels of aging observed in the atmosphere, due to too little oxidation and sometimes too high concentrations (Ng et al., ACPD, 2009). When plotted in a Van Krevelen diagram (H/C vs O/C), the OA evolution in multiple field studies from Mexico City to the pristine Amazon basin is consistent with the addition of carboxylic acids (Heald et al., GRL, submitted, 2009). A two-dimensional basis set using organic O/C and volatility (C*) as its coordinates can reproduce the lab and field observations and should allow faster model development because it is experimentally verifiable (Jimenez et al., Science, 2009; Donahue et al., in prep., 2010). An alternative 2D basis set based on carbon number and mean carbon oxidation state provides very useful insights about the nature and evolution of gas and particulate-phase organic species (Kroll et al., in

  2. Provenance and basin evolution, Zhada basin, southwestern Tibet

    NASA Astrophysics Data System (ADS)

    Saylor, J.; Decelles, P.; Gehrels, G.; Kapp, P.

    2007-12-01

    The Zhada basin is a late Miocene - Pliocene intermontane basin situated at high elevations in the Himalayan hinterland. The fluvial and lacustrine sediments of the Zhada formation are undeformed and sit in angular unconformity above the deformed Tethyan Sedimentary Sequence (TSS). The basin sits just south of the Indus suture in a structural position occupied elsewhere in the Himalayan orogen by some of the highest mountains on earth, including Everest. The occurrence of a basin at this location demands explanation. Currently, the Sutlej River flows parallel to the structural grain of the Himalaya, westward through the basin, towards the Leo Pargil (Qusum) range. Near the range front it takes a sharp southward turn, cuts across the structural grain of the Himalaya and out into the Gangetic foreland. Palaeocurrent indicators in the lower part of the Zhada formation show that the basin originated as a northwest flowing axial river. Palaeocurrent indicators are consistently northwest oriented, even to within to within 10 km of the Leo Pargil range front in the north-western end of the basin. This implies that at the onset of sedimentation in Zhada basin the Leo Pargil range was not a barrier as it is today. In the upper part of the Zhada formation, palaeocurrent indicators are generally directed towards the centre of the basin. In the central and southern portions of the basin this indicates a transition from an axial, northwest flowing river to prograding fluvial and alluvial fans. However, in the north-western part of the basin the change between lower and upper Zhada formation involves a complete drainage reversal. This change in palaeocurrent orientation is also reflected in the detrital zircon signal from basin sediments. Low in the Zhada formation the detrital zircon signal is dominated by zircons from the Kailash (Gangdese) batholith (or associated extrusives, see below). However, higher in the sections, a local source, either from the TSS or the core of the Leo Pargil range dominates the detrital zircon signal. Finally, there is a shift in the sandstone composition from unmetamorphosed sedimentary lithic fragments and extrusive felsic volcanic fragments in the lower part of the Zhada formation to metasedimentary and metaigneous fragments in the upper part of the Zhada formation. This is likely linked either to unroofing of the source terrain or a change to another source terrain. Based on the palaeocurrent and detrital zircon data, a change to another source terrain is favoured. This combination of evidence suggests that the Zhada basin evolved from a through-going fluvial plain to a dammed lake primarily due to uplift of the Leo Pargil range. This uplift would have dammed and ponded the river, and exposed higher grade metamorphic rocks at the surface for incorporation into Zhada formation sandstones. It also would have introduced a new source for detrital zircons. Uplift of the Leo Pargil range along a low angle normal fault would also have evacuated portions of the mid-crust, providing a mechanism for subsidence in the Zhada region. Lacustrine sedimentation would have coincided with progradation of marginal alluvial fans and would have continued until the basin was filled in to the level of a new spill point. At this time incision and re- establishment of the Sutlej River would have occurred.

  3. Provenance for Earth Science Data Systems

    NASA Astrophysics Data System (ADS)

    Hua, H.; Tilmes, C.; Ramapriyan, H. K.; Duggan, B.; Wilson, B. D.; Manipon, G. J. M.

    2014-12-01

    Earth Science Data Systems across NASA play a critical role in data processing, management, and analysis of NASA observations. However, there is a growing need to provide the provenance of these datasets as scientists increasingly need more transparency of the data products to improve their understanding and trust of the science results. Lessons learned from Climategate show that there is public demand for more transparency and understanding in the science process. Science data systems are key to enabling the capture, management, and use of production provenance information. Science analysis now also may involve merging multi-sensor datasets where lineage can facilitate the understanding of the data. But there does not exist a formal recommendation for an interoperable standard for provenance representation for use in NASA's Earth Science Data Systems. The W3C Provenance Working Group has a specification for the representation of provenance information. The standard is very general and intended to support the breadth of any domain. To better serve the needs of specific domain communities, the standard has several built in points of extensibility. We will present efforts by NASA's Earth Science Data Systems Working Group (ESDSWG) on Provenance to develop an Earth Science extension to the PROV specification (PROV-ES) and how it can be used in science data system to capture, consume, and interpret provenance information.

  4. MODEL OF THE FIELD LINE RANDOM WALK EVOLUTION AND APPROACH TO ASYMPTOTIC DIFFUSION IN MAGNETIC TURBULENCE

    SciTech Connect

    Snodin, A. P.; Ruffolo, D.; Matthaeus, W. H. E-mail: david.ruf@mahidol.ac.th

    2013-01-01

    The turbulent random walk of magnetic field lines plays an important role in the transport of plasmas and energetic particles in a wide variety of astrophysical situations, but most theoretical work has concentrated on determination of the asymptotic field line diffusion coefficient. Here we consider the evolution with distance of the field line random walk using a general ordinary differential equation (ODE), which for most cases of interest in astrophysics describes a transition from free streaming to asymptotic diffusion. By challenging theories of asymptotic diffusion to also describe the evolution, one gains insight on how accurately they describe the random walk process. Previous theoretical work has effectively involved closure of the ODE, often by assuming Corrsin's hypothesis and a Gaussian displacement distribution. Approaches that use quasilinear theory and prescribe the mean squared displacement ({Delta}x {sup 2}) according to free streaming (random ballistic decorrelation, RBD) or asymptotic diffusion (diffusive decorrelation, DD) can match computer simulation results, but only over specific parameter ranges, with no obvious 'marker' of the range of validity. Here we make use of a unified description in which the ODE determines ({Delta}x {sup 2}) self-consistently, providing a natural transition between the assumptions of RBD and DD. We find that the minimum kurtosis of the displacement distribution provides a good indicator of whether the self-consistent ODE is applicable, i.e., inaccuracy of the self-consistent ODE is associated with non-Gaussian displacement distributions.

  5. An effective continuum approach for modeling non-equilibrium structural evolution of protein nanofiber networks

    NASA Astrophysics Data System (ADS)

    Cheng, Liang; Englander, Ongi; Paravastu, Anant; Oates, William S.

    2011-08-01

    We quantify the formation and evolution of protein nanofibers using a new phase field modeling framework and compare the results to transmission electron microscopy measurements (TEM) and time-dependent growth measurements given in the literature. The modeling framework employs a set of effective continuum equations combined with underlying nanoscale forces and chemical potential relations governing protein nanofiber formation in solution. Calculations based on the theoretical framework are implemented numerically using a nonlinear finite element phase field modeling approach that couples homogenized protein molecular structure via a vector order parameter with chemical potential relations that describe interactions between the nanofibers and the surrounding solution. Homogenized, anisotropic molecular and chemical flux relations are found to be critical in obtaining nanofiber growth from seed particles or a random monomer bath. In addition, the model predicts both sigmoidal and first-order growth kinetics for protein nanofibers for unseeded and seeded models, respectively. These simulations include quantitative predictions on time scales of typical protein self-assembly behavior which qualitatively match TEM measurements of the RADA16-I protein and growth rate measurements for amyloid nanofibers from the literature. For comparisons with experiments, the numerical model performs multiple nanofiber protein evolution simulations with a characteristic length scale of ˜2.4 nm and characteristic time scale of ˜9.1 h. These results provide a new modeling tool that couples underlying monomer structure with self-assembling nanofiber behavior that is compatible with various external loadings and chemical environments.

  6. Soft-computing approach to plasma evolution tracking in tokamak reactors

    NASA Astrophysics Data System (ADS)

    Morabito, Francesco C.

    1997-10-01

    Qualitative information about the structure of a mapping can surely be of help in learning a mapping by a collection of input-output pairs. However, there are conditions in which time and some other constraints make guessing the only plausible means for interpreting data. In this paper, the problem of the plasma boundary reconstruction in 'Tokamak' nuclear fusion rectors is assessed. The problem is formulated as an inverse 'identification' problem and the mapping is derived by a properly generated database of simulated experiments. Real data coming from experiments are also available to validate both numerically generated data and extracted model. The identification problem is solved for two different databases by using neural networks and more conventional models. The introduction of techniques derived from soft computing is shown to improve the performance in various respects. Dynamic identification systems appear to be rather demanding also for such systems, for the need of rapidly interpreting real time data for discharge control. Soft computing approaches may yet yield some low cost ways to take decisions during plasma evolution. The approximate analysis of experimental data could also improve the knowledge on the particular problem allowing an evolution of the knowledge base. Experimental data related to ASDEX-Upgrade machine are presented in this work and preliminary processed. Soft computing techniques also allow to simply get ideas about two other interesting problems in plasma engineering, namely, the fault tolerance and the minimization of the number of sensors.

  7. An effective continuum approach for modeling non-equilibrium structural evolution of protein nanofiber networks.

    PubMed

    Cheng, Liang; Englander, Ongi; Paravastu, Anant; Oates, William S

    2011-08-01

    We quantify the formation and evolution of protein nanofibers using a new phase field modeling framework and compare the results to transmission electron microscopy measurements (TEM) and time-dependent growth measurements given in the literature. The modeling framework employs a set of effective continuum equations combined with underlying nanoscale forces and chemical potential relations governing protein nanofiber formation in solution. Calculations based on the theoretical framework are implemented numerically using a nonlinear finite element phase field modeling approach that couples homogenized protein molecular structure via a vector order parameter with chemical potential relations that describe interactions between the nanofibers and the surrounding solution. Homogenized, anisotropic molecular and chemical flux relations are found to be critical in obtaining nanofiber growth from seed particles or a random monomer bath. In addition, the model predicts both sigmoidal and first-order growth kinetics for protein nanofibers for unseeded and seeded models, respectively. These simulations include quantitative predictions on time scales of typical protein self-assembly behavior which qualitatively match TEM measurements of the RADA16-I protein and growth rate measurements for amyloid nanofibers from the literature. For comparisons with experiments, the numerical model performs multiple nanofiber protein evolution simulations with a characteristic length scale of ∼2.4 nm and characteristic time scale of ∼9.1 h. These results provide a new modeling tool that couples underlying monomer structure with self-assembling nanofiber behavior that is compatible with various external loadings and chemical environments. PMID:21823733

  8. Trickle-down evolution: an approach to getting major evolutionary adaptive changes into textbooks and curricula.

    PubMed

    Padian, Kevin

    2008-08-01

    Although contemporary high school and college textbooks of biology generally cover the principles and data of microevolution (genetic and populational change) and speciation rather well, coverage of what is known of the major changes in evolution (macroevolution), and how the evidence is understood is generally poor to nonexistent. It is critical to improve this because acceptance of evolution by the American public rests on the understanding of how we know what we know about the emergence of major new taxonomic groups, and about their adaptations, behaviors, and ecologies in geologic time. An efficient approach to this problem is to improve the illustrations in college textbooks to show the consilience of different lines of fossil, morphological, and molecular evidence mapped on phylogenies. Such "evograms" will markedly improve traditional illustrations of phylogenies, "menageries," and "companatomies." If "evograms" are installed at the college level, the basic principles and evidence of macroevolution will be more likely taught in K-12, thus providing an essential missing piece in biological education. PMID:21669782

  9. Cultural transmission and the evolution of human behaviour: a general approach based on the Price equation.

    PubMed

    El Mouden, C; André, J-B; Morin, O; Nettle, D

    2014-02-01

    Transmitted culture can be viewed as an inheritance system somewhat independent of genes that is subject to processes of descent with modification in its own right. Although many authors have conceptualized cultural change as a Darwinian process, there is no generally agreed formal framework for defining key concepts such as natural selection, fitness, relatedness and altruism for the cultural case. Here, we present and explore such a framework using the Price equation. Assuming an isolated, independently measurable culturally transmitted trait, we show that cultural natural selection maximizes cultural fitness, a distinct quantity from genetic fitness, and also that cultural relatedness and cultural altruism are not reducible to or necessarily related to their genetic counterparts. We show that antagonistic coevolution will occur between genes and culture whenever cultural fitness is not perfectly aligned with genetic fitness, as genetic selection will shape psychological mechanisms to avoid susceptibility to cultural traits that bear a genetic fitness cost. We discuss the difficulties with conceptualizing cultural change using the framework of evolutionary theory, the degree to which cultural evolution is autonomous from genetic evolution, and the extent to which cultural change should be seen as a Darwinian process. We argue that the nonselection components of evolutionary change are much more important for culture than for genes, and that this and other important differences from the genetic case mean that different approaches and emphases are needed for cultural than genetic processes. PMID:24329934

  10. Multi-analytical approach applied to the provenance study of marbles used as covering slabs in the archaeological submerged site of Baia (Naples, Italy): The case of the "Villa con ingresso a protiro"

    NASA Astrophysics Data System (ADS)

    Ricca, Michela; Belfiore, Cristina Maria; Ruffolo, Silvestro Antonio; Barca, Donatella; De Buergo, Monica Alvarez; Crisci, Gino Mirocle; La Russa, Mauro Francesco

    2015-12-01

    This paper is focused on archaeometric investigations of white marbles taken from the submerged archaeological site of Baia (Naples). The marine area includes the ruins of this ancient Roman city, whose structures range from luxurious maritime villas and imperial buildings with private thermae and tabernae, to more simple and modest houses. Analyses were carried out on fifty marble fragments of covering slabs, belonging to several pavements of the monumental villa, called the Villa con ingresso a protiro, in order to ascertain their provenance. The most distinctive properties of marbles are their variety of textural property especially regarding grain size (MGS), associated with the Mn content and the variation of stable isotopes. These features, supported by the contribution of other variables and studies, establish the basis for the correct identification of the marbles. For this purpose, minero-petrographic and geochemical techniques were used. Results were compared with literature data of white marbles commonly used in antiquity, especially in the Mediterranean basin and showed that a variety of precious marbles from Carrara, Docimium (Afyon), Thasos-D, Aphrodisias, Proconnesos (Marmara), Paros and Pentelicon were used in the ancient roman city of Baia, confirming the importance of the submerged archaeological site and also allowing researchers to broaden the existing database.

  11. Phase evolution of magnetite nanocrystals on oxide supports via template-free bismuth ferrite precursor approach

    NASA Astrophysics Data System (ADS)

    Cheung, Jeffrey; Bogle, Kashinath; Cheng, Xuan; Sullaphen, Jivika; Kuo, Chang-Yang; Chen, Ying-Jiun; Lin, Hong-Ji; Chen, Chien-Te; Yang, Jan-Chi; Chu, Ying-Hao; Valanoor, Nagarajan

    2012-11-01

    This report investigates the phase evolution pathway of magnetite nanocrystal synthesis on oxide-supported substrates. A template-free phase separation approach, which exploits the thermodynamic instability of ternary perovskite BiFeO3 and inherent volatility of bismuth oxide in low oxygen pressure and high temperature is presented. The formation of an intermediate hematite nanocrystal phase is found as a key step that controls the eventual size and morphology of the magnetite nanocrystals. X-ray absorption spectra measurements and X-ray magnetic circular dichroism confirm that the spectral fingerprints of the magnetite nanocrystals match with that of bulk crystals. Magnetic measurements show that magnetic anisotropy is directly attributed to the nanocrystal morphology.

  12. Ground Segment Reference Architectures: An Approach for Cost Effective Systems Evolution

    NASA Astrophysics Data System (ADS)

    Marley, S.; Hansen, D.; Brown, C.

    2011-12-01

    The era of mission specific stovepipe ground systems is drawing to a close. As on-orbit processing capabilities and asset durability continue to improve, the cost of maintaining ground segment implementations can become the limiting factor for when missions are no longer operationally viable. Cost effective evolution demands a new approach to designing ground systems that is evolvable to changing mission needs, adaptable to new technologies and emerging paradigms, and scalable to "peta-scale" data management applications. Ground segment implementations need to be guided by a robust reference architecture that provides a framework in which new mission capability can be deployed, legacy systems can be migrated, and data management services optimized. This presentation describes key architectural drivers and associated patterns for developing the next generation of adaptable and scalable ground systems in order to provide cost effective, long term mission viability.

  13. Respiratory consequences of prematurity: evolution of a diagnosis and development of a comprehensive approach.

    PubMed

    Maitre, N L; Ballard, R A; Ellenberg, J H; Davis, S D; Greenberg, J M; Hamvas, A; Pryhuber, G S

    2015-05-01

    Bronchopulmonary dysplasia (BPD) is the most common respiratory consequence of premature birth and contributes to significant short- and long-term morbidity, mortality and resource utilization. Initially defined as a radiographic, clinical and histopathological entity, the chronic lung disease known as BPD has evolved as obstetrical and neonatal care have improved the survival of lower gestational age infants. Now, definitions based on the need for supplementary oxygen at 28 days and/or 36 weeks provide a useful reference point in the neonatal intensive-care unit (NICU), but are no longer based on histopathological findings, and are neither designed to predict longer term respiratory consequences nor to study the evolution of a multifactorial disease. The aims of this review are to critically examine the evolution of the diagnosis of BPD and the challenges inherent to current classifications. We found that the increasing use of respiratory support strategies that administer ambient air without supplementary oxygen confounds oxygen-based definitions of BPD. Furthermore, lack of reproducible, genetic, biochemical and physiological biomarkers limits the ability to identify an impending BPD for early intervention, quantify disease severity for standardized classification and approaches and reliably predict the long-term outcomes. More comprehensive, multidisciplinary approaches to overcome these challenges involve longitudinal observation of extremely preterm infants, not only those with BPD, using genetic, environmental, physiological and clinical data as well as large databases of patient samples. The Prematurity and Respiratory Outcomes Program (PROP) will provide such a framework to address these challenges through high-resolution characterization of both NICU and post-NICU discharge outcomes. PMID:25811285

  14. Galaxy evolution simulation of the basement of linguo-combinatorial approach

    NASA Astrophysics Data System (ADS)

    Ignatyev, Mikhail B.

    2015-08-01

    Galaxy - complex self-organizing systems, therefore they are subject to the identified patterns of development of complex systems (see. M.B.Ignatyev "The linguo-combinatorial simulation in modern physics"\\ J. of Modern Physics? USA, 2012, No 1, p.7-11). As part of the linguo- combinatorial approach complex systems described by the equivalent equation with arbitrary coefficients, the matrix of which depends on the number of variables and the number of restrictions. The number of arbitrary coefficients is determined by the number of combinations of n by m + 1, where n - the number of different elements of the galaxy, m - the number of constraints imposed on them. The number of arbitrary coefficients characterizes the adaptive capacity of the galactic system. In the evolution of a galaxy passes through a maximum adaptation and gradually turns into a rigid system that either die or are transformed through creative transition - see Fig. .Fig. Transformation of developing galaxies, n1 evolution of galaxies on the basement of linguo- combinatorial approach.

  15. Understanding Student Approaches to Learning Evolution in the Context of their Perceptions of the Relationship between Science and Religion

    NASA Astrophysics Data System (ADS)

    Yasri, Pratchayapong; Mancy, Rebecca

    2014-01-01

    This study investigates a range of positions that learners take on the relationship between science and religion and the potential for these positions to explain student approaches when learning about evolution. A phenomenographic study based on interviews with nine students studying in Christian high schools in Thailand led to the identification of five distinct positions on the relationship between science and religion. Each position was associated with a characteristic pattern of learning about evolution that could be explained as an attempt by the students to align their particular learning approach with their position. Three of the positions have the potential to support scientifically valid understandings of evolution while avoiding emotional conflict. We suggest that knowledge of the range of positions and associated learning approaches can help educators to focus on the form and timing of support of benefit to those holding different viewpoints.

  16. A holomorph approach to xiphosuran evolution--a case study on the ontogeny of Euproops.

    PubMed

    Haug, Carolin; Van Roy, Peter; Leipner, Angelika; Funch, Peter; Rudkin, David M; Schöllmann, Lothar; Haug, Joachim T

    2012-09-01

    Specimens of Euproops sp. (Xiphosura, Chelicerata) from the Carboniferous Piesberg quarry near Osnabrück, Germany, represent a relatively complete growth series of 10 stages. Based on this growth sequence, morphological changes throughout the ontogeny can be identified. The major change affects the shape of the epimera of the opisthosoma. In earlier stages, they appear very spine-like, whereas in later stages the bases of these spine-like structures become broader; the broadened bases are then successively drawn out distally. In the most mature stage known, the epimera are of trapezoidal shape and approach each other closely to form a complete flange around the thoracetron (=fused tergites of the opisthosoma). These ontogenetic changes question the taxonomic status of different species of Euproops, as the latter appear to correspond to different stages of the ontogenetic series reconstructed from the Piesberg specimens. This means that supposed separate species could, in fact, represent different growth stages of a single species. It could alternatively indicate that heterochrony (=evolutionary change of developmental timing) plays an important role in the evolution of Xiphosura. We propose a holomorph approach, i.e., reconstructing ontogenetic sequences for fossil and extant species as a sound basis for a taxonomic, phylogenetic, and evolutionary discussion of Xiphosura. PMID:22915218

  17. Flame-based processing as a practical approach for manufacturing hydrogen evolution electrodes

    NASA Astrophysics Data System (ADS)

    Roller, Justin; Renner, Julie; Yu, Haoran; Capuano, Chris; Kwak, Tony; Wang, Yang; Carter, C. Barry; Ayers, Kathy; Mustain, William E.; Maric, Radenka

    2014-12-01

    Catalyst structure and morphology are inevitably dictated by the synthesis route, which in-turn dictates catalyst activity, stability and utilization in the electrode. Reactive spray deposition technology (RSDT) is a promising synthesis route for electrode manufacturing because of the potential to achieve high-throughput processing under a diverse range of process configurations. This work investigates several unique approaches to Pt catalyst deposition using jet-flame synthesis for water electrolysis electrodes. Direct application of the catalyst film onto Nafion 117 and carbon paper is explored along with approaches to dispersing the Pt onto carbon or TinO2n-1. Operational challenges relating to the harsh conditions of H2 evolution and electrode adhesion are addressed by adding binder and catalyst support to the electrode structure. The RSDT technology produces an electrode, coated directly onto Nafion 117®, with a 20-fold reduction in Pt loading while maintaining high in-cell performance (2.1 V at 2 A cm-2) compared to an industry-level baseline. Durability testing at 1.8 A cm-2, 400 psi differential pressure and a temperature of 50 °C yields a consistent potential of ∼2.2 V for over 1100 h without failure. The same electrode applied directly to carbon paper resulted in a voltage of ∼2.1 V for ∼600 h without failure.

  18. Fuzzy reasoning of accident provenance in pervasive healthcare monitoring systems.

    PubMed

    Wang, Yongli; Hu, Xiaohua

    2013-11-01

    In pervasive healthcare monitoring environments, data provenance, as one metadata, can help people analyze the reasons for medical accidents that are generated by complex events. This reasoning processing often encounters inaccurate time and irreversible reasoning problems. How to solve the uncertain process and fuzzy transformation time presents many challenges to the study of data provenance. In this paper, we propose a backward derivation model with the provenance semantic, backward fuzzy time reasoning net (BFTRN), to solve these two problems. We design a backward reasoning algorithm motivated by time automation theory based on this model. With regard to given life-critical alarms and some constraints, it cannot only derive all evolution paths and the possibility distribution of paths from historical information, but also efficiently compute the value of fuzzy time function for each transition of lift-critical complex alarms in the healthcare monitoring system. We also analyze the properties of BFTRN model in this paper. Experiments on real dataset show that the proposed model is efficient. PMID:24240719

  19. An innovative approach to predict technology evolution for the desoldering of printed circuit boards: A perspective from China and America.

    PubMed

    Wang, Chen; Zhao, Wu; Wang, Jie; Chen, Ling; Luo, Chun-Jing

    2016-06-01

    The printed circuit boards basis of electronic equipment have seen a rapid growth in recent years and played a significant role in modern life. Nowadays, the fact that electronic devices upgrade quickly necessitates a proper management of waste printed circuit boards. Non-destructive desoldering of waste printed circuit boards becomes the first and the most crucial step towards recycling electronic components. Owing to the diversity of materials and components, the separation process is difficult, which results in complex and expensive recovery of precious materials and electronic components from waste printed circuit boards. To cope with this problem, we proposed an innovative approach integrating Theory of Inventive Problem Solving (TRIZ) evolution theory and technology maturity mapping system to forecast the evolution trends of desoldering technology of waste printed circuit boards. This approach can be applied to analyse the technology evolution, as well as desoldering technology evolution, then research and development strategy and evolution laws can be recommended. As an example, the maturity of desoldering technology is analysed with a technology maturity mapping system model. What is more, desoldering methods in different stages are analysed and compared. According to the analysis, the technological evolution trends are predicted to be 'the law of energy conductivity' and 'increasing the degree of idealisation'. And the potential technology and evolutionary state of waste printed circuit boards are predicted, offering reference for future waste printed circuit boards recycling. PMID:27067430

  20. The evolution of the Thuringian Syncline (Central Germany) - an interdisciplinary approach to basin reconstruction

    NASA Astrophysics Data System (ADS)

    Malz, Alexander; Beyer, Daniel; Donndorf, Stephan; Navabpour, Payman; Voigt, Thomas; Aehnelt, Michaela; Kley, Jonas

    2014-05-01

    extensional with small normal offsets, were later reactivated as reverse faults, can explain a significantly higher initial amount of fault-controlled subsidence. The distribution of vitrinite reflectance data indicates a scenario of structural evolution, which is consistent with similar structures of the North German Basin. Our project shows that an interdisciplinary approach can put close constraints on modelling and reconstruction of basin evolution even with incomplete stratigraphic record.

  1. Provenance in Observational Solar Physics Data Pipelines

    NASA Astrophysics Data System (ADS)

    McGuinness, D.; Fox, P.; Garcia, J.; Zednik, S.

    2008-05-01

    A limiting factor for virtual observatories which intend to make diverse data sets available to a diverse user base is that the following use cases are very difficult to implement: 1. Determine which flat field calibration was applied to the image taken on January, 26, 2005 around 2100UT by the ACOS Mark IV polarimeter. 2. What processing steps were completed to obtain the ACOS PICS limb image of the day for January 26, 2005. 3. What was the cloud cover and atmospheric seeing conditions during the local morning of January 26, 2005 at MLSO. Key to addressing these use cases often requires information that was either not collected from different stages in the data processing pipeline or it was but was not carried forward when the datasets were made available on-line. Collectively, this information is called provenance and in a semantic web data framework; knowledge provenance. In this presentation, we describe the knowledge provenance requirements that have emerged in our previous work on virtual observatories as well as requirements identified from a series of uses cases collected from scientific data users and instrument scientists. We will describe the progress we are making on meeting these requirements in the context of solar physics image data processing pipelines. The Semantic Provenance Capture in Data Ingest Systems (SPCDIS) is a NSF OCI/SDCI-funded project to implement an extensible meta data provenance scheme within the Virtual Solar-Terrestrial Observatory.

  2. An R package for statistical provenance analysis

    NASA Astrophysics Data System (ADS)

    Vermeesch, Pieter; Resentini, Alberto; Garzanti, Eduardo

    2016-05-01

    This paper introduces provenance, a software package within the statistical programming environment R, which aims to facilitate the visualisation and interpretation of large amounts of sedimentary provenance data, including mineralogical, petrographic, chemical and isotopic provenance proxies, or any combination of these. provenance comprises functions to: (a) calculate the sample size required to achieve a given detection limit; (b) plot distributional data such as detrital zircon U-Pb age spectra as Cumulative Age Distributions (CADs) or adaptive Kernel Density Estimates (KDEs); (c) plot compositional data as pie charts or ternary diagrams; (d) correct the effects of hydraulic sorting on sandstone petrography and heavy mineral composition; (e) assess the settling equivalence of detrital minerals and grain-size dependence of sediment composition; (f) quantify the dissimilarity between distributional data using the Kolmogorov-Smirnov and Sircombe-Hazelton distances, or between compositional data using the Aitchison and Bray-Curtis distances; (e) interpret multi-sample datasets by means of (classical and nonmetric) Multidimensional Scaling (MDS) and Principal Component Analysis (PCA); and (f) simplify the interpretation of multi-method datasets by means of Generalised Procrustes Analysis (GPA) and 3-way MDS. All these tools can be accessed through an intuitive query-based user interface, which does not require knowledge of the R programming language. provenance is free software released under the GPL-2 licence and will be further expanded based on user feedback.

  3. Simulating mesoscale coastal evolution for decadal coastal management: A new framework integrating multiple, complementary modelling approaches

    NASA Astrophysics Data System (ADS)

    van Maanen, Barend; Nicholls, Robert J.; French, Jon R.; Barkwith, Andrew; Bonaldo, Davide; Burningham, Helene; Brad Murray, A.; Payo, Andres; Sutherland, James; Thornhill, Gillian; Townend, Ian H.; van der Wegen, Mick; Walkden, Mike J. A.

    2016-03-01

    Coastal and shoreline management increasingly needs to consider morphological change occurring at decadal to centennial timescales, especially that related to climate change and sea-level rise. This requires the development of morphological models operating at a mesoscale, defined by time and length scales of the order 101 to 102 years and 101 to 102 km. So-called 'reduced complexity' models that represent critical processes at scales not much smaller than the primary scale of interest, and are regulated by capturing the critical feedbacks that govern landform behaviour, are proving effective as a means of exploring emergent coastal behaviour at a landscape scale. Such models tend to be computationally efficient and are thus easily applied within a probabilistic framework. At the same time, reductionist models, built upon a more detailed description of hydrodynamic and sediment transport processes, are capable of application at increasingly broad spatial and temporal scales. More qualitative modelling approaches are also emerging that can guide the development and deployment of quantitative models, and these can be supplemented by varied data-driven modelling approaches that can achieve new explanatory insights from observational datasets. Such disparate approaches have hitherto been pursued largely in isolation by mutually exclusive modelling communities. Brought together, they have the potential to facilitate a step change in our ability to simulate the evolution of coastal morphology at scales that are most relevant to managing erosion and flood risk. Here, we advocate and outline a new integrated modelling framework that deploys coupled mesoscale reduced complexity models, reductionist coastal area models, data-driven approaches, and qualitative conceptual models. Integration of these heterogeneous approaches gives rise to model compositions that can potentially resolve decadal- to centennial-scale behaviour of diverse coupled open coast, estuary and inner

  4. Sediment generation and provenance: processes and pathways

    NASA Astrophysics Data System (ADS)

    Caracciolo, L.; Garzanti, E.; von Eynatten, H.; Weltje, G. J.

    2016-05-01

    The ability to trace sediments from their sources to sedimentary basins is a prerequisite for quantitative analysis of Earth-surface dynamics. The comparatively recent revival of sedimentary provenance analysis goes hand-in-hand with the ever expanding range of analytical tools available for quantifying sediment properties (isotopic, mineral, chemical, and petrographic composition, grain-size and shape distributions, age spectra, etc.), and for interpreting such data in paleo-geographic, -tectonic and -climatic terms. The breakdown of sediment budgets into source-specific contributions - one of the most important tasks of provenance analysis - permits quantification of rates of surface processes in the geological past ("deep time"), even in cases where the source areas themselves have been destroyed by global tectonics. Quantitative sedimentary provenance analysis is therefore crucial to the reconstruction of ancient sediment-routing systems, the fundamental units of mass transfer at the Earth's surface.

  5. A new approach to the automatic identification of organism evolution using neural networks.

    PubMed

    Kasperski, Andrzej; Kasperska, Renata

    2016-01-01

    Automatic identification of organism evolution still remains a challenging task, which is especially exiting, when the evolution of human is considered. The main aim of this work is to present a new idea to allow organism evolution analysis using neural networks. Here we show that it is possible to identify evolution of any organisms in a fully automatic way using the designed EvolutionXXI program, which contains implemented neural network. The neural network has been taught using cytochrome b sequences of selected organisms. Then, analyses have been carried out for the various exemplary organisms in order to demonstrate capabilities of the EvolutionXXI program. It is shown that the presented idea allows supporting existing hypotheses, concerning evolutionary relationships between selected organisms, among others, Sirenia and elephants, hippopotami and whales, scorpions and spiders, dolphins and whales. Moreover, primate (including human), tree shrew and yeast evolution has been reconstructed. PMID:26975238

  6. Understanding Student Approaches to Learning Evolution in the Context of Their Perceptions of the Relationship between Science and Religion

    ERIC Educational Resources Information Center

    Yasri, Pratchayapong; Mancy, Rebecca

    2014-01-01

    This study investigates a range of positions that learners take on the relationship between science and religion and the potential for these positions to explain student approaches when learning about evolution. A phenomenographic study based on interviews with nine students studying in Christian high schools in Thailand led to the identification…

  7. Time-dependent evolution of rock slopes by a multi-modelling approach

    NASA Astrophysics Data System (ADS)

    Bozzano, F.; Della Seta, M.; Martino, S.

    2016-06-01

    This paper presents a multi-modelling approach that incorporates contributions from morpho-evolutionary modelling, detailed engineering-geological modelling and time-dependent stress-strain numerical modelling to analyse the rheological evolution of a river valley slope over approximately 102 kyr. The slope is located in a transient, tectonically active landscape in southwestern Tyrrhenian Calabria (Italy), where gravitational processes drive failures in rock slopes. Constraints on the valley profile development were provided by a morpho-evolutionary model based on the correlation of marine and river strath terraces. Rock mass classes were identified through geomechanical parameters that were derived from engineering-geological surveys and outputs of a multi-sensor slope monitoring system. The rock mass classes were associated to lithotechnical units to obtain a high-resolution engineering-geological model along a cross section of the valley. Time-dependent stress-strain numerical modelling reproduced the main morpho-evolutionary stages of the valley slopes. The findings demonstrate that a complex combination of eustatism, uplift and Mass Rock Creep (MRC) deformations can lead to first-time failures of rock slopes when unstable conditions are encountered up to the generation of stress-controlled shear zones. The multi-modelling approach enabled us to determine that such complex combinations may have been sufficient for the first-time failure of the S. Giovanni slope at approximately 140 ka (MIS 7), even without invoking any trigger. Conversely, further reactivations of the landslide must be related to triggers such as earthquakes, rainfall and anthropogenic activities. This failure involved a portion of the slope where a plasticity zone resulted from mass rock creep that evolved with a maximum strain rate of 40% per thousand years, after the formation of a river strath terrace. This study demonstrates that the multi-modelling approach presented herein is a useful

  8. Nonstationary porosity evolution in mixing zone in coastal carbonate aquifer using an alternative modeling approach.

    PubMed

    Laabidi, Ezzeddine; Bouhlila, Rachida

    2015-07-01

    In the last few decades, hydrogeochemical problems have benefited from the strong interest in numerical modeling. One of the most recognized hydrogeochemical problems is the dissolution of the calcite in the mixing zone below limestone coastal aquifer. In many works, this problem has been modeled using a coupling algorithm between a density-dependent flow model and a geochemical model. A related difficulty is that, because of the high nonlinearity of the coupled set of equations, high computational effort is needed. During calcite dissolution, an increase in permeability can be identified, which can induce an increase in the penetration of the seawater into the aquifer. The majority of the previous studies used a fully coupled reactive transport model in order to model such problem. Romanov and Dreybrodt (J Hydrol 329:661-673, 2006) have used an alternative approach to quantify the porosity evolution in mixing zone below coastal carbonate aquifer at steady state. This approach is based on the analytic solution presented by Phillips (1991) in his book Flow and Reactions in Permeable Rock, which shows that it is possible to decouple the complex set of equation. This equation is proportional to the square of the salinity gradient, which can be calculated using a density driven flow code and to the reaction rate that can be calculated using a geochemical code. In this work, this equation is used in nonstationary step-by-step regime. At each time step, the quantity of the dissolved calcite is quantified, the change of porosity is calculated, and the permeability is updated. The reaction rate, which is the second derivate of the calcium equilibrium concentration in the equation, is calculated using the PHREEQC code (Parkhurst and Apello 1999). This result is used in GEODENS (Bouhlila 1999; Bouhlila and Laabidi 2008) to calculate change of the porosity after calculating the salinity gradient. For the next time step, the same protocol is used but using the updated porosity

  9. High resolution remote sensing image segmentation based on graph theory and fractal net evolution approach

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Li, H. T.; Han, Y. S.; Gu, H. Y.

    2015-06-01

    Image segmentation is the foundation of further object-oriented image analysis, understanding and recognition. It is one of the key technologies in high resolution remote sensing applications. In this paper, a new fast image segmentation algorithm for high resolution remote sensing imagery is proposed, which is based on graph theory and fractal net evolution approach (FNEA). Firstly, an image is modelled as a weighted undirected graph, where nodes correspond to pixels, and edges connect adjacent pixels. An initial object layer can be obtained efficiently from graph-based segmentation, which runs in time nearly linear in the number of image pixels. Then FNEA starts with the initial object layer and a pairwise merge of its neighbour object with the aim to minimize the resulting summed heterogeneity. Furthermore, according to the character of different features in high resolution remote sensing image, three different merging criterions for image objects based on spectral and spatial information are adopted. Finally, compared with the commercial remote sensing software eCognition, the experimental results demonstrate that the efficiency of the algorithm has significantly improved, and the result can maintain good feature boundaries.

  10. Health needs assessment in primary care: the evolution of a practical public health approach.

    PubMed

    Kilduff, A; McKeown, K; Crowther, A

    1998-05-01

    The purpose of the paper is to place health needs assessment in its primary care context. This is a dynamic context where changes in policies, staff roles and patient expectations have all to be considered. Given this complexity and the variations between practices, it is necessary to help primary health care teams (PHCTs) to understand their stage of development and how this will directly affect any health needs assessment. The technical and methodological aspects of health needs assessment have been explored and described by others, and that work will not be duplicated here. This paper reviews the health needs assessment (HNA) work of the Ribblesdale Total Purchasing Project (RTPP) and then sets this review against the political, organisational, professional and practical pressures that currently confront primary care. Out of this analysis emerges a diagnostic and development tool which links together, and emphasises the intimate relationships between, five stages of development needed for effective primary care-oriented health needs assessment work. The emphasis is on understanding the place of health needs assessment within the general processes and systems of the primary health care team. The paper concludes by suggesting ways in which public health practitioners and specialists might approach the task of supporting and influencing the evolution of the recently proposed Primary Care Groups and Primary Care Trusts. The overall intention of the article is to stimulate debate and action. PMID:9629025

  11. Trends in morphological evolution in homobasidiomycetes inferred using maximum likelihood: a comparison of binary and multistate approaches.

    PubMed

    Hibbett, David

    2004-12-01

    The homobasidiomycetes is a diverse group of macrofungi that includes mushrooms, puffballs, coral fungi, and other forms. This study used maximum likelihood methods to determine if there are general trends (evolutionary tendencies) in the evolution of fruiting body forms in homobasidiomycetes, and to estimate the ancestral forms of the homobasidiomycetes and euagarics clade. Character evolution was modeled using a published 481-species phylogeny under two character-coding regimes: additive binary coding, using DISCRETE, and multistate (five-state) coding, using MULTISTATE. Inferences regarding trends in character evolution made under binary coding were often in conflict with those made under multistate coding, suggesting that the additive binary coding approach cannot serve as a surrogate for multistate methods. MULTISTATE was used to develop a"minimal"model of fruiting body evolution, in which the 20 parameters that specify rates of transformations among character states were grouped into the fewest possible rate categories. The minimal model required only four rate categories, one of which is approaching zero, and suggests the following conclusions regarding trends in evolution of homobasidiomycete fruiting bodies: (1) there is an active trend favoring the evolution of pileate-stipitate forms (those with a cap and stalk); (2) the hypothesis that the evolution of gasteroid forms (those with internal spore production, such as puffballs) is irreversible cannot be rejected; and (3) crustlike resupinate forms are not a particularly labile morphology. The latter finding contradicts the conclusions of a previous study that used binary character coding. Ancestral state reconstructions under binary coding suggest that the ancestor of the homobasidiomycetes was resupinate and the ancestor of the euagarics clade was pileate-stipitate, but ancestral state reconstructions under multistate coding did not resolve the ancestral form of either node. The results of this study

  12. Applying Content Management to Automated Provenance Capture

    SciTech Connect

    Schuchardt, Karen L.; Gibson, Tara D.; Stephan, Eric G.; Chin, George

    2008-04-10

    Workflows and data pipelines are becoming increasingly valuable in both computational and experimen-tal sciences. These automated systems are capable of generating significantly more data within the same amount of time than their manual counterparts. Automatically capturing and recording data prove-nance and annotation as part of these workflows is critical for data management, verification, and dis-semination. Our goal in addressing the provenance challenge was to develop and end-to-end system that demonstrates real-time capture, persistent content management, and ad-hoc searches of both provenance and metadata using open source software and standard protocols. We describe our prototype, which extends the Kepler workflow tools for the execution environment, the Scientific Annotation Middleware (SAM) content management software for data services, and an existing HTTP-based query protocol. Our implementation offers several unique capabilities, and through the use of standards, is able to pro-vide access to the provenance record to a variety of commonly available client tools.

  13. An Algebraic Approach to the Evolution of Emittances upon Crossing the Linear Coupling Difference Resonance

    SciTech Connect

    Gardner,C.

    2008-09-01

    One of the hallmarks of linear coupling is the resonant exchange of oscillation amplitude between the horizontal and vertical planes when the difference between the unperturbed tunes is close to an integer. The standard derivation of this phenomenon (known as the difference resonance) can be found, for example, in the classic papers of Guignard [1, 2]. One starts with an uncoupled lattice and adds a linear perturbation that couples the two planes. The equations of motion are expressed in hamiltonian form. As the difference between the unperturbed tunes approaches an integer, one finds that the perturbing terms in the hamiltonian can be divided into terms that oscillate slowly and ones that oscillate rapidly. The rapidly oscillating terms are discarded or transformed to higher order with an appropriate canonical transformation. The resulting approximate hamiltonian gives equations of motion that clearly exhibit the exchange of oscillation amplitude between the two planes. If, instead of the hamiltonian, one is given the four-by-four matrix for one turn around a synchrotron, then one has the complete solution for the turn-by-turn (TBT) motion. However, the conditions for the phenomenon of amplitude exchange are not obvious from a casual inspection of the matrix. These conditions and those that give rise to the related sum resonance are identified in this report. The identification is made using the well known formalism of Edwards and Teng [3, 4, 5] and, in particular, the normalized coupling matrix of Sagan and Rubin [6]. The formulae obtained are general in that no particular hamiltonian or coupling elements are assumed. The only assumptions are that the one-turn matrix is symplectic and that it has distinct eigenvalues on the unit circle in the complex plane. Having identified the conditions of the one-turn matrix that give rise to the resonances, we focus on the difference resonance and apply the formulae to the evolution of the horizontal and vertical emittances

  14. Structure and Evolution of Mediterranean Forest Research: A Science Mapping Approach

    PubMed Central

    Nardi, Pierfrancesco; Di Matteo, Giovanni; Palahi, Marc; Scarascia Mugnozza, Giuseppe

    2016-01-01

    This study aims at conducting the first science mapping analysis of the Mediterranean forest research in order to elucidate its research structure and evolution. We applied a science mapping approach based on co-term and citation analyses to a set of scientific publications retrieved from the Elsevier’s Scopus database over the period 1980–2014. The Scopus search retrieved 2,698 research papers and reviews published by 159 peer-reviewed journals. The total number of publications was around 1% (N = 17) during the period 1980–1989 and they reached 3% (N = 69) in the time slice 1990–1994. Since 1995, the number of publications increased exponentially, thus reaching 55% (N = 1,476) during the period 2010–2014. Within the thirty-four years considered, the retrieved publications were published by 88 countries. Among them, Spain was the most productive country, publishing 44% (N = 1,178) of total publications followed by Italy (18%, N = 482) and France (12%, N = 336). These countries also host the ten most productive scientific institutions in terms of number of publications in Mediterranean forest subjects. Forest Ecology and Management and Annals of Forest Science were the most active journals in publishing research in Mediterranean forest. During the period 1980–1994, the research topics were poorly characterized, but they become better defined during the time slice 1995–1999. Since 2000s, the clusters become well defined by research topics. Current status of Mediterranean forest research (20092014) was represented by four clusters, in which different research topics such as biodiversity and conservation, land-use and degradation, climate change effects on ecophysiological responses and soil were identified. Basic research in Mediterranean forest ecosystems is mainly conducted by ecophysiological research. Applied research was mainly represented by land-use and degradation, biodiversity and conservation and fire research topics. The citation analyses

  15. Structure and Evolution of Mediterranean Forest Research: A Science Mapping Approach.

    PubMed

    Nardi, Pierfrancesco; Di Matteo, Giovanni; Palahi, Marc; Scarascia Mugnozza, Giuseppe

    2016-01-01

    This study aims at conducting the first science mapping analysis of the Mediterranean forest research in order to elucidate its research structure and evolution. We applied a science mapping approach based on co-term and citation analyses to a set of scientific publications retrieved from the Elsevier's Scopus database over the period 1980-2014. The Scopus search retrieved 2,698 research papers and reviews published by 159 peer-reviewed journals. The total number of publications was around 1% (N = 17) during the period 1980-1989 and they reached 3% (N = 69) in the time slice 1990-1994. Since 1995, the number of publications increased exponentially, thus reaching 55% (N = 1,476) during the period 2010-2014. Within the thirty-four years considered, the retrieved publications were published by 88 countries. Among them, Spain was the most productive country, publishing 44% (N = 1,178) of total publications followed by Italy (18%, N = 482) and France (12%, N = 336). These countries also host the ten most productive scientific institutions in terms of number of publications in Mediterranean forest subjects. Forest Ecology and Management and Annals of Forest Science were the most active journals in publishing research in Mediterranean forest. During the period 1980-1994, the research topics were poorly characterized, but they become better defined during the time slice 1995-1999. Since 2000s, the clusters become well defined by research topics. Current status of Mediterranean forest research (20092014) was represented by four clusters, in which different research topics such as biodiversity and conservation, land-use and degradation, climate change effects on ecophysiological responses and soil were identified. Basic research in Mediterranean forest ecosystems is mainly conducted by ecophysiological research. Applied research was mainly represented by land-use and degradation, biodiversity and conservation and fire research topics. The citation analyses revealed highly

  16. A new approach to parton recombination in the QCD evolution equations

    NASA Astrophysics Data System (ADS)

    Wei Zhu

    1999-06-01

    Parton recombination is reconsidered in perturbation theory without using the AGK cutting rules in the leading order of the recombination. We use time-ordered perturbation theory to sum the cut diagrams, which are neglected in the GLR evolution equation. We present a set of new evolution equations including parton recombination.

  17. Characterizing Provenance in Visualization and Data Analysis: An Organizational Framework of Provenance Types and Purposes.

    PubMed

    Ragan, Eric D; Endert, Alex; Sanyal, Jibonananda; Chen, Jian

    2016-01-01

    While the primary goal of visual analytics research is to improve the quality of insights and findings, a substantial amount of research in provenance has focused on the history of changes and advances throughout the analysis process. The term, provenance, has been used in a variety of ways to describe different types of records and histories related to visualization. The existing body of provenance research has grown to a point where the consolidation of design knowledge requires cross-referencing a variety of projects and studies spanning multiple domain areas. We present an organizational framework of the different types of provenance information and purposes for why they are desired in the field of visual analytics. Our organization is intended to serve as a framework to help researchers specify types of provenance and coordinate design knowledge across projects. We also discuss the relationships between these factors and the methods used to capture provenance information. In addition, our organization can be used to guide the selection of evaluation methodology and the comparison of study outcomes in provenance research. PMID:26340779

  18. Characterizing Provenance in Visualization and Data Analysis: An Organizational Framework of Provenance Types and Purposes

    DOE PAGESBeta

    Ragan, Eric; Alex, Endert; Sanyal, Jibonananda; Chen, Jian

    2016-01-01

    While the primary goal of visual analytics research is to improve the quality of insights and findings, a substantial amount of research in provenance has focused on the history of changes and advances throughout the analysis process. The term, provenance, has been used in a variety of ways to describe different types of records and histories related to visualization. The existing body of provenance research has grown to a point where the consolidation of design knowledge requires cross-referencing a variety of projects and studies spanning multiple domain areas. We present an organizational framework of the different types of provenance informationmore » and purposes for why they are desired in the field of visual analytics. Our organization is intended to serve as a framework to help researchers specify types of provenance and coordinate design knowledge across projects. We also discuss the relationships between these factors and the methods used to capture provenance information. In addition, our organization can be used to guide the selection of evaluation methodology and the comparison of study outcomes in provenance research« less

  19. Characterizing Provenance in Visualization and Data Analysis: An Organizational Framework of Provenance Types and Purposes

    SciTech Connect

    Ragan, Eric; Alex, Endert; Sanyal, Jibonananda; Chen, Jian

    2016-01-01

    While the primary goal of visual analytics research is to improve the quality of insights and findings, a substantial amount of research in provenance has focused on the history of changes and advances throughout the analysis process. The term, provenance, has been used in a variety of ways to describe different types of records and histories related to visualization. The existing body of provenance research has grown to a point where the consolidation of design knowledge requires cross-referencing a variety of projects and studies spanning multiple domain areas. We present an organizational framework of the different types of provenance information and purposes for why they are desired in the field of visual analytics. Our organization is intended to serve as a framework to help researchers specify types of provenance and coordinate design knowledge across projects. We also discuss the relationships between these factors and the methods used to capture provenance information. In addition, our organization can be used to guide the selection of evaluation methodology and the comparison of study outcomes in provenance research

  20. The stones and historic mortars of the Santissima Trinità di Saccargia Romanesque Basilica (Sardinia, Italy): a multi-analytical techniques' approach for the study of their features and provenance

    NASA Astrophysics Data System (ADS)

    Columbu, Stefano; Palomba, Marcella; Sitzia, Fabio

    2015-04-01

    A research project devoted to the study of building materials of the Romanesque churches in Sardinia is currently underway. One of the objectives of the project is to focus the mineral, chemical-physical and petrographic characterisation of the construction materials, as well as the alteration processes. To make a contribution to the preservation of Sardinian monuments, we suggests a new approach to define the different alteration-modes of rocks in function of their local exposure to the weather, studying: 1) the changes of physical properties on surface of stone (porosity, water absorption, micro-morphology) determined through laboratory tests and photogrammetry observations, 2) the alteration phases present on surface (e.g., secondary minerals, soluble salts) determined by mineralogical and chemical investigations. This methodological approach will allow to select appropriate, suitable and compatible materials for replacing the original altered one's, and to plan appropriate strategies devoted to the restoration work. In this paper the geomaterials used for construct the Santissima Trinità di Saccargia Basilica have been investigated. The church, finished in 1116 over the ruins of a pre-existing monastery, is the most important Romanesque site in the island. Have been studied the chemical alterations and physical decay of two different stones, as volcanic rocks (i.e., basalt) and sedimentary rocks (i.e., limestones) used in bichromy on the Basilica. The main purpose is to observe the different modes of alteration of these two lithologies with different petrophysical characteristics, placed in the same conditions of weathering. Macroscopic evidences show that the limestones, while not having a high porosity, they were strongly affected by alteration phenomena, especially in the outer surface of ashlars, due to the solubilization of the carbonate matrix. The basalt rocks show no obvious physical alteration. Occasionally, in some ashlar located in basal zone of the

  1. Thermodynamically consistent phase field approach to dislocation evolution at small and large strains

    NASA Astrophysics Data System (ADS)

    Levitas, Valery I.; Javanbakht, Mahdi

    2015-09-01

    A thermodynamically consistent, large strain phase field approach to dislocation nucleation and evolution at the nanoscale is developed. Each dislocation is defined by an order parameter, which determines the magnitude of the Burgers vector for the given slip planes and directions. The kinematics is based on the multiplicative decomposition of the deformation gradient into elastic and plastic contributions. The relationship between the rates of the plastic deformation gradient and the order parameters is consistent with phenomenological crystal plasticity. Thermodynamic and stability conditions for homogeneous states are formulated and satisfied by the proper choice of the Helmholtz free energy and the order parameter dependence on the Burgers vector. They allow us to reproduce desired lattice instability conditions and a stress-order parameter curve, as well as to obtain a stress-independent equilibrium Burgers vector and to avoid artificial dissipation during elastic deformation. The Ginzburg-Landau equations are obtained as the linear kinetic relations between the rate of change of the order parameters and the conjugate thermodynamic driving forces. A crystalline energy coefficient for dislocations is defined as a periodic step-wise function of the coordinate along the normal to the slip plane, which provides an energy barrier normal to the slip plane and determines the desired, mesh-independent height of the dislocation bands for any slip system orientation. Gradient energy contains an additional term, which excludes the localization of a dislocation within a height smaller than the prescribed height, but it does not produce artificial interface energy. An additional energy term is introduced that penalizes the interaction of different dislocations at the same point. Non-periodic boundary conditions for dislocations are introduced which include the change of the surface energy due to the exit of dislocations from the crystal. Obtained kinematics, thermodynamics

  2. Novel Approaches to Manipulating Bacterial Pathogen Biofilms: Whole-Systems Design Philosophy and Steering Microbial Evolution.

    PubMed

    Penn, Alexandra S

    2016-01-01

    Understanding and manipulating bacterial biofilms is crucial in medicine, ecology and agriculture and has potential applications in bioproduction, bioremediation and bioenergy. Biofilms often resist standard therapies and the need to develop new means of intervention provides an opportunity to fundamentally rethink our strategies. Conventional approaches to working with biological systems are, for the most part, "brute force", attempting to effect control in an input and effort intensive manner and are often insufficient when dealing with the inherent non-linearity and complexity of living systems. Biological systems, by their very nature, are dynamic, adaptive and resilient and require management tools that interact with dynamic processes rather than inert artefacts. I present an overview of a novel engineering philosophy which aims to exploit rather than fight those properties, and hence provide a more efficient and robust alternative. Based on a combination of evolutionary theory and whole-systems design, its essence is what I will call systems aikido; the basic principle of aikido being to interact with the momentum of an attacker and redirect it with minimal energy expenditure, using the opponent's energy rather than one's own. In more conventional terms, this translates to a philosophy of equilibrium engineering, manipulating systems' own self-organisation and evolution so that the evolutionarily or dynamically stable state corresponds to a function which we require. I illustrate these ideas with a description of a proposed manipulation of environmental conditions to alter the stability of co-operation in the context of Pseudomonas aeruginosa biofilm infection of the cystic fibrosis lung. PMID:27193553

  3. Phenotypic evolution of human craniofacial morphology after admixture: a geometric morphometrics approach.

    PubMed

    Martínez-Abadías, Neus; González-José, Rolando; González-Martín, Antonio; Van der Molen, Silvina; Talavera, Arturo; Hernández, Patricia; Hernández, Miquel

    2006-03-01

    An evolutionary, diachronic approach to the phenotypic craniofacial pattern arisen in a human population after high levels of admixture and gene flow was achieved by means of geometric morphometrics. Admixture has long been studied after molecular data. Nevertheless, few efforts have been made to explain the morphological outcome in human craniofacial samples. The Spanish-Amerindian contact can be considered a good scenario for such an analysis. Here we present a comparative analysis of craniofacial shape changes observed between two putative ancestor groups, Spanish and precontact Aztecs, and two diachronic admixed groups, corresponding to early and late colonial periods from the Mexico's Central Valley. Quantitative shape comparisons of Amerindian, Spanish, and admixed groups were used to test the expectations of quantitative genetics for admixture events. In its simplest form, this prediction states that an admixed group will present phenotypic values falling between those of both parental groups. Results show that, in general terms, although the human skull is a complex, integrated structure, the craniofacial morphology observed fits the theoretical expectations of quantitative genetics. Thus, it is predictive of population structure and history. In fact, results obtained after the craniofacial analysis are in accordance with previous molecular and historical interpretations, providing evidence that admixture is a main microevolutionary agent influencing modern Mexican gene pool. However, expectations are not straightforward when moderate shape changes are considered. Deviations detected at localized structures, such as the upper and lower face, highlight the evolution of a craniofacial pattern exclusively inherent to the admixed groups, indicating that quantitative characters might respond to admixture in a complicated, nondirectional way. PMID:16323202

  4. Provenance Representation in the Global Change Information System (GCIS)

    NASA Technical Reports Server (NTRS)

    Tilmes, Curt

    2012-01-01

    Global climate change is a topic that has become very controversial despite strong support within the scientific community. It is common for agencies releasing information about climate change to be served with Freedom of Information Act (FOIA) requests for everything that led to that conclusion. Capturing and presenting the provenance, linking to the research papers, data sets, models, analyses, observation instruments and satellites, etc. supporting key findings has the potential to mitigate skepticism in this domain. The U.S. Global Change Research Program (USGCRP) is now coordinating the production of a National Climate Assessment (NCA) that presents our best understanding of global change. We are now developing a Global Change Information System (GCIS) that will present the content of that report and its provenance, including the scientific support for the findings of the assessment. We are using an approach that will present this information both through a human accessible web site as well as a machine readable interface for automated mining of the provenance graph. We plan to use the developing W3C PROV Data Model and Ontology for this system.

  5. DNA DSB measurements and modelling approaches based on gamma-H2AX foci time evolution

    NASA Astrophysics Data System (ADS)

    Esposito, Giuseppe; Campa, Alessandro; Antonelli, Francesca; Mariotti, Luca; Belli, Mauro; Giardullo, Paola; Simone, Giustina; Antonella Tabocchini, Maria; Ottolenghi, Andrea

    DNA double strand breaks (DSBs) induced by ionising radiation are considered the main dam-age related to the deleterious consequences in the cells. Unrepaired or mis-repaired DSBs can cause mutations or loss of chromosome regions which can eventually lead to cell death or neo-plastic transformation. Quantification of the number and complexity of DSBs induced by low doses of radiation remains a complex problem. About ten years ago Rogakou et al. proposed an immunofluorescent technique able to detect even a single DSB per cell. This approach is based on the serine 139 phosphorylation of many molecules (up to 2000) of histone H2AX (γg-H2AX) following the induction of a DSB in the DNA. DSB can be visualized as foci by immunofluores-cence by using phospho-specific antibodies, so that enumeration of foci can be used to measure DSB induction and processing. It is still not completely clear how γ-H2AX dephosphorylation takes place; however it has been related with DSB repair, in particular with the efficiency of DSB repair. In this work we analyse the H2AX phosphorylation-dephosphorylation kinetics after irradiation of primary human fibroblasts (AG1522 cell line) with radiation of differing quality, that is γ-rays and α-particles (125 keV/µm), with the aim of comparing the time evolution of γ-H2AX foci. Our results show that, after a dose of 0.5 Gy, both γ-rays and α-particles induce the maximum number of γ-H2AX foci within 30 minutes from irradiation, that this number depends on the radiation type and is consistent with the number of track traversal in α-irradiated nuclei, that the dephosphorylation kinetics are very different, being the α-induced foci rate of disappearence slower than that of γ-induced foci. In this work a modellistic approach to estimate the number of DSB induced by γ-rays detectable by using the γ-H2AX assay is presented. The competing processes of appearance and disappearance of visible foci will be modeled taking into account the

  6. Tracking Files Using the Kepler Provenance Framework

    SciTech Connect

    Pierre, Mouallem; Vouk, Mladen; Klasky, Scott A; Tchoua, Roselyne B; Podhorszki, Norbert

    2009-01-01

    Workflow Management Systems (WFMS), such as Kepler, are proving to be an important tool in scientific problem solving. They can automate and manage complex processes and huge amounts of data produced by petascale simulations. Typically, the produced data need to be properly visualized and analyzed by scientists in order to achieve the desired scientific goals. Both run-time and post analysis may benefit from, even require, additional meta-data - provenance information. One of the challenges in this context is the tracking of the data files that can be produced in very large numbers during stages of the workflow, such as visualizations. The Kepler provenance framework collects all or part of the raw information flowing through the workflow graph. This information then needs to be further parsed to extract meta-data of interest. This can be done through add-on tools and algorithms. We show how to automate tracking specific information such as data files locations.

  7. Tracking Files Using the Kepler Provenance Framework

    SciTech Connect

    Mouallem, P. A.; Tchoua, Roselyne B; Klasky, Scott A; Podhorszki, Norbert; Vouk, M. A.

    2009-01-01

    Workflow Management Systems (WFMS), such as Kepler, are prov- ing to be an important tool in scientific problem solving. They can automate and manage complex processes and huge amounts of data produced by petas- cale simulations. Typically, the produced data need to be properly visualized and analyzed by scientists in order to achieve the desired scientific goals. Both run-time and post analysis may benefit from, even require, additional meta-data provenance information. One of the challenges in this context is the tracking of the data files that can be produced in very large numbers during stages of the workflow, such as visualizations. The Kepler provenance framework collects all or part of the raw information flowing through the workflow graph. This infor- mation then needs to be further parsed to extract meta-data of interest. This can be done through add-on tools and algorithms. We show how to automate track- ing specific information such as data files locations.

  8. Tracking Files in the Kepler Provenance Framework

    SciTech Connect

    Mouallem, Pierre A; Klasky, Scott A; Podhorszki, Norbert; Vouk, Mladen

    2009-01-01

    Workflow Management Systems (WFMS), such as Kepler, are proving to be an important tool in scientific problem solving. They can automate and manage complex processes and huge amounts of data produced by petascale simulations. Typically, the produced data need to be properly visualized and analyzed by scientists in order to achieve the desired scientific goals. Both run-time and post analysis may benefit from, even require, additional meta-data - provenance information. One of the challenges in this context is the tracking of the data files that can be produced in very large numbers during stages of the workflow, such as visualizations. The Kepler provenance framework collects all or part of the raw information flowing through the workflow graph. This information then needs to be further parsed to extract meta-data of interest. This can be done through add-on tools and algorithms. We show how to automate tracking specific information such as data files locations.

  9. A Bayesian Approach to the Evolution of Metabolic Networks on a Phylogeny

    PubMed Central

    Mithani, Aziz; Preston, Gail M.; Hein, Jotun

    2010-01-01

    The availability of genomes of many closely related bacteria with diverse metabolic capabilities offers the possibility of tracing metabolic evolution on a phylogeny relating the genomes to understand the evolutionary processes and constraints that affect the evolution of metabolic networks. Using simple (independent loss/gain of reactions) or complex (incorporating dependencies among reactions) stochastic models of metabolic evolution, it is possible to study how metabolic networks evolve over time. Here, we describe a model that takes the reaction neighborhood into account when modeling metabolic evolution. The model also allows estimation of the strength of the neighborhood effect during the course of evolution. We present Gibbs samplers for sampling networks at the internal node of a phylogeny and for estimating the parameters of evolution over a phylogeny without exploring the whole search space by iteratively sampling from the conditional distributions of the internal networks and parameters. The samplers are used to estimate the parameters of evolution of metabolic networks of bacteria in the genus Pseudomonas and to infer the metabolic networks of the ancestral pseudomonads. The results suggest that pathway maps that are conserved across the Pseudomonas phylogeny have a stronger neighborhood structure than those which have a variable distribution of reactions across the phylogeny, and that some Pseudomonas lineages are going through genome reduction resulting in the loss of a number of reactions from their metabolic networks. PMID:20700467

  10. Implementing Provenance Collection in a Legacy Data Product Generation System

    NASA Astrophysics Data System (ADS)

    Conover, H.; Ramachandran, R.; Kulkarni, A.; Beaumont, B.; McEniry, M.; Graves, S. J.; Goodman, H.

    2012-12-01

    NASA has been collecting, storing, archiving and distributing vast amounts of Earth science data derived from satellite observations for several decades now. The raw data collected from the different sensors undergoes many different transformations before it is distributed to the science community as climate-research-quality data products. These data transformations include calibration, geolocation, and conversion of the instrument counts into meaningful geophysical parameters, and may include reprojection and/or spatial and temporal averaging as well. In the case of many Earth science data systems, the science algorithms and any ancillary data files used for these transformations are delivered as a "black box" to be integrated into the data system's processing framework. In contrast to an experimental workflow that may vary with each iteration, such systems use consistent, well-engineered processes to apply the same science algorithm to each well-defined set of inputs in order to create standard data products. Even so, variability is inevitably introduced. There may be changes made to the algorithms, different ancillary datasets may be used, underlying hardware and software may get upgraded, etc. Furthermore, late-arriving input data, operator error, or other processing anomalies may necessitate regeneration and replacement of a particular set of data files and any downstream products. These variations need to be captured, documented and made accessible to the scientific community so they can be properly accounted for in analyses. This presentation describes an approach to provenance capture, storage and dissemination implemented at the NASA Science Investigator-led Processing System (SIPS) for the AMSR-E (Advanced Microwave Scanning Radiometer - Earth Observing System) instrument. Key considerations in adding provenance capabilities to this legacy data system include: (1) granularity of provenance information captured, (2) additional context information needed

  11. Obsidian provenance research in the Americas.

    PubMed

    Glascock, Michael D

    2002-08-01

    The characterization of archaeological materials to support provenance research has grown rapidly over the past few decades. Volcanic obsidian has several unique properties that make it the ideal archaeological material for studying prehistoric trade and exchange. This Account describes our laboratory's development of a systematic methodology for the characterization of obsidian sources and artifacts from Mesoamerica and other regions of North and South America in support of archaeological research. PMID:12186565

  12. Multi-scale Science: Supporting Emerging Practice with Semantically Derived Provenance

    SciTech Connect

    Myers, James D.; Pancerella, Carmen M.; Lansing, Carina S.; Schuchardt, Karen L.; Didier, Brett T.; Ashish, N., Goble, C

    2003-10-20

    Scientific progress is becoming increasingly dependent of our ability to study phenomena at multiple scales and from multiple perspectives. The ability to recontextualize third party data within the semantic and syntactic framework of a given research project is increasingly seen as a primary barrier in multi-scale science. Within the Collaboratory for Multiscale Chemical Science (CMCS) project, we are developing a general-purpose informatics-based approach that emphasizes ''on-demand'' metadata creation, configurable data translations, and semantic mapping to support the rapidly increasing and continually evolving requirements for managing data, metadata, and data relationships in such projects. A concrete example of this approach is the design of the CMCS provenance subsystem. The concept of provenance varies across communities, and multiple independent applications contribute to and use provenance. In CMCS, we have developed generic tools for viewing provenance relationships and for using them to, for example, scope notifications and searches. These tools rely on a configurable concept of provenance defined in terms of other relationships. The result is a very flexible mechanism capable of tracking data provenance across many disciplines and supporting multiple uses of provenance information.

  13. An event-driven approach for studying gene block evolution in bacteria

    PubMed Central

    Ream, David C.; Bankapur, Asma R.; Friedberg, Iddo

    2015-01-01

    Motivation: Gene blocks are genes co-located on the chromosome. In many cases, gene blocks are conserved between bacterial species, sometimes as operons, when genes are co-transcribed. The conservation is rarely absolute: gene loss, gain, duplication, block splitting and block fusion are frequently observed. An open question in bacterial molecular evolution is that of the formation and breakup of gene blocks, for which several models have been proposed. These models, however, are not generally applicable to all types of gene blocks, and consequently cannot be used to broadly compare and study gene block evolution. To address this problem, we introduce an event-based method for tracking gene block evolution in bacteria. Results: We show here that the evolution of gene blocks in proteobacteria can be described by a small set of events. Those include the insertion of genes into, or the splitting of genes out of a gene block, gene loss, and gene duplication. We show how the event-based method of gene block evolution allows us to determine the evolutionary rateand may be used to trace the ancestral states of their formation. We conclude that the event-based method can be used to help us understand the formation of these important bacterial genomic structures. Availability and implementation: The software is available under GPLv3 license on http://github.com/reamdc1/gene_block_evolution.git. Supplementary online material: http://iddo-friedberg.net/operon-evolution Contact: i.friedberg@miamioh.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25717195

  14. From static to dynamic provenance analysis-Sedimentary petrology upgraded

    NASA Astrophysics Data System (ADS)

    Garzanti, Eduardo

    2016-05-01

    The classical approach to sandstone petrology, established in the golden years of plate tectonics and based on the axiom that "detrital modes of sandstone suites primarily reflect the different tectonic settings of provenance terranes," has represented a benchmark for decades. The composition of sand and sandstone, however, simply provides us with a distorted image of the lithological structure of source terranes and gives us little clue whether they are allochthonous or autochthonous, orogenic or anorogenic, young or old. What we may able to see reflected in detrital modes is the nature of source terranes (continental, arc, oceanic) and the tectonostratigraphic level reached by erosion in space and time. The proposed new approach to the petrology of sand and sandstone (1) starts with a simple classification scheme circulated since the 1960s, which is purely descriptive, objective, and free of ill-defined ambiguous terms and (2) focuses on the nature and tectonostratigraphic level of source terranes. Further steps are essential to upgrade provenance analysis. Acquiring knowledge from modern settings is needed to properly identify and wherever possible correct for physical and chemical processes introducing environmental and diagenetic bias and thus address nature's complexities with adequate conceptual tools. Equally important is the integration of multiple techniques, ideally including bulk-sediment, multi-mineral, and single-mineral methods. Bulk-sediment petrography remains the fundamental approach that allows us to capture the most precious source of direct provenance information, represented by the mineralogy and texture of rock fragments. Bulk-sediment geochemistry, applicable also to silt and clay carried in suspension, is a superior method to check for hydraulic sorting, chemical weathering, and fertility of detrital minerals in different sediment sources. Detrital geochronology, thermochronology, and isotope geochemistry reveal the diverse time structures

  15. Functions and possible provenance of primordial proteins.

    PubMed

    Sommer, Andrei P; Miyake, Norimune; Wickramasinghe, N Chandra; Narlikar, Jayant V; Al-Mufti, Shirwan

    2004-01-01

    Nanobacteria or living nanovesicles are of great interest to the scientific community because of their dual nature: on the one hand, they appear as primal biosystems originating life; on the other hand, they can cause severe diseases. Their survival as well as their pathogenic potential is apparently linked to a self-synthesized protein-based slime, rich in calcium and phosphate (when available). Here, we provide challenging evidence for the occurrence of nanobacteria in the stratosphere, reflecting a possibly primordial provenance of the slime. An analysis of the slime's biological functions may lead to novel strategies suitable to block adhesion modalities in modern bacterial populations. PMID:15595742

  16. An ecological and behavioural approach to hominin evolution during the Pliocene

    NASA Astrophysics Data System (ADS)

    Macho, Gabriele A.

    2014-07-01

    The study considers the turnover in hominins, together with carnivorans and other primates, at 3.5 Ma against an environmental backdrop. Communalities are identified between evolving guilds that may directly inform hominin evolution. These are the evolution of (a) dietary generalists and (b) evidence for sociality in carnivores, baboons and hominins. Sociality and behavioural flexibility are regarded advantageous for the procurement of resources while, at the same time, reducing intraspecific competition; in primates it may initially also have served to reduce predation risk. Behavioural flexibility explains the evolutionary success of Panthera leo, Papio and Homo. Viewed within a wider palaeoecological and environmental context, it is possible that sociality in hominins, including allocare, were triggered by abiotic changes at about 3.5 Ma. If confirmed in future studies, this would mark the beginning of hominin life history evolution.

  17. Multi-Input Single Output SSSC based damping controller design by a hybrid Improved Differential Evolution-Pattern Search approach.

    PubMed

    Panda, Sidhartha; Yegireddy, Narendra Kumar

    2015-09-01

    In this paper, a hybrid Improved Differential Evolution and Pattern Search (hIDEPS) approach is proposed for the design of a PI-Type Multi-Input Single Output (MISO) Static Synchronous Series Compensator (SSSC) based damping controller. The improvement in Differential Evolution (DE) algorithm is introduced by a simple but effective scheme of changing two of its most important control parameters i.e. step size and crossover probability with an objective of achieving improved performance. Pattern Search (PS) is subsequently employed to fine tune the best solution provided by modified DE algorithm. The superiority of a proposed hIDEPS technique over DE and improved DE has also been demonstrated. At the outset, this concept is applied to a SSSC connected in a Single Machine Infinite Bus (SMIB) power system and then extended to a multi-machine power system. To show the effectiveness and robustness of the proposed design approach, simulation results are presented and compared with DE and Particle Swarm Optimization (PSO) optimized Single Input Single Output (SISO) SSSC based damping controllers. It is observed that the proposed approach yield superior damping performance compared to some approaches available in the literature. PMID:25864132

  18. A Hybrid Particle Swarm with Differential Evolution Operator Approach (DEPSO) for Linear Array Synthesis

    NASA Astrophysics Data System (ADS)

    Sarkar, Soham; Das, Swagatam

    In recent years particle swarm optimization emerges as one of the most efficient global optimization tools. In this paper, a hybrid particle swarm with differential evolution operator, termed DEPSO, is applied for the synthesis of linear array geometry. Here, the minimum side lobe level and null control, both are obtained by optimizing the spacing between the array elements by this technique. Moreover, a statistical comparison is also provided to establish its performance against the results obtained by Genetic Algorithm (GA), classical Particle Swarm Optimization (PSO), Tabu Search Algorithm (TSA), Differential Evolution (DE) and Memetic Algorithm (MA).

  19. Actualistic Ophiolite Provenance: The Cyprus Case.

    PubMed

    Garzanti; Andò; Scutellà

    2000-03-01

    The island of Cyprus represents an excellent site to assess quantitatively petrologic clastic response to actively obducting oceanic sources in order to define an actualistic reference for ophiolite provenance, in terms of framework composition and heavy mineral suites. An improved methodology, an extension of the classic ternary QFL logic to include a wider spectrum of key indexes and ratios, provides an accurate synthesis of modal data and allows differentiation of three main petrographic provinces and at least seven subprovinces. Diagnostic signatures of detritus from various levels of an oceanic lithospheric source, and criteria for distinguishing provenance from suprasubduction versus mid-oceanic ophiolites are also outlined. Modern sands derived from the Troodos Ophiolite contain variable proportions of largely pelagic carbonate to chert, boninite to basalt, diabase to metabasite, plagiogranite to gabbroic, and cumulate grains supplied from progressively deeper-seated levels of the multilayered oceanic crust. Dense minerals are mainly clinopyroxenes (diopside), prevailing over orthopyroxenes (enstatite, hypersthene, clinoenstatite), hornblende, tremolite/actinolite, and epidote. Where serpentinized mantle harzburgites have been unroofed, detritus is markedly enriched in cellular serpentinite grains and enstatite, with still negligible olivine and spinel. Sedimentaclastic sands dominated by chert (Mamonia Province) or carbonate grains (Kyrenia Province) are deposited along the southern and northern shores of the island, respectively. Compositions of Cyprus sands are virtually unaffected by climatic, sedimentary, or anthropic processes; recycling of sandstones from foreign sources is a major process only in the Karpaz Peninsula. Petrographic analysis also provides an independent mean to identify prevalent directions of longshore sand transport. PMID:10736270

  20. Insights into the Diversity of Attitudes Concerning Evolution and Creation: A Multidimensional Approach

    ERIC Educational Resources Information Center

    Konneman, Christiane; Asshoff, Roman; Hammann, Marcus

    2016-01-01

    The main aim of this paper is to describe high school students' attitudes concerning evolution and creation, with a focus on (1) attitudes toward evolutionary theory, (2) attitudes toward the Biblical accounts of creation, (3) creationist beliefs, and (4) scientistic beliefs. Latent class analyses revealed seven attitude profiles in a sample of…

  1. Addressing Controversies in Science Education: A Pragmatic Approach to Evolution Education

    ERIC Educational Resources Information Center

    Hildebrand, David; Bilica, Kimberly; Capps, John

    2008-01-01

    Science education controversies typically prove more intractable than those in scientific research because they involve a wider range of considerations (e.g., epistemic, social, ethical, political, and religious). How can educators acknowledge central issues in a controversy (such as evolution)? How can such problems be addressed in a way that is…

  2. Computers in Biological Education: Simulation Approaches. Genetics and Evolution. CAL Research Group Technical Report No. 13.

    ERIC Educational Resources Information Center

    Murphy, P. J.

    Three examples of genetics and evolution simulation concerning Mendelian inheritance, genetic mapping, and natural selection are used to illustrate the use of simulations in modeling scientific/natural processes. First described is the HERED series, which illustrates such phenomena as incomplete dominance, multiple alleles, lethal alleles,…

  3. Evolution of conformational changes in the dynamics of small biological molecules: a hybrid MD/RRK approach.

    PubMed

    Segev, Elad; Grumbach, Mikael; Gerber, Robert Benny

    2006-11-14

    The dynamics of long timescale evolution of conformational changes in small biological molecules is described by a hybrid molecular dynamics/RRK algorithm. The approach employs classical trajectories for transitions between adjacent structures separated by a low barrier, and the classical statistical RRK approximation when the barrier involved is high. In determining the long-time dynamics from an initial structure to a final structure of interest, an algorithm is introduced for determining the most efficient pathways (sequence of the intermediate conformers). This method uses the Dijkstra algorithm for finding optimal paths on networks. Three applications of the method using an AMBER force field are presented: a detailed study of conformational transitions in a blocked valine dipeptide; a multiple reaction path study of the blocked valine tripeptide; and the evolution in time from the beta hairpin to alpha helix structure of a blocked alanine hexapeptide. Advantages and limitations of the method are discussed in light of the results. PMID:17066182

  4. An interactive approach based on a discrete differential evolution algorithm for a class of integer bilevel programming problems

    NASA Astrophysics Data System (ADS)

    Li, Hong; Zhang, Li; Jiao, Yong-Chang

    2016-07-01

    This paper presents an interactive approach based on a discrete differential evolution algorithm to solve a class of integer bilevel programming problems, in which integer decision variables are controlled by an upper-level decision maker and real-value or continuous decision variables are controlled by a lower-level decision maker. Using the Karush--Kuhn-Tucker optimality conditions in the lower-level programming, the original discrete bilevel formulation can be converted into a discrete single-level nonlinear programming problem with the complementarity constraints, and then the smoothing technique is applied to deal with the complementarity constraints. Finally, a discrete single-level nonlinear programming problem is obtained, and solved by an interactive approach. In each iteration, for each given upper-level discrete variable, a system of nonlinear equations including the lower-level variables and Lagrange multipliers is solved first, and then a discrete nonlinear programming problem only with inequality constraints is handled by using a discrete differential evolution algorithm. Simulation results show the effectiveness of the proposed approach.

  5. Standardized wellheads proven economical for subsea operations

    SciTech Connect

    Moreira, C.C.; Silva Paulo, C.A. )

    1994-05-02

    A standardization program for subsea wellheads and completion equipment has made development of Brazil's offshore fields more economical and efficient. The resulting operational flexibility associated with the use of field-proven equipment and procedures saves rig time and can reduce production loss during workovers. Additionally, investments can be rationalized economically by installing part of the completion equipment at the end of the drilling job and then delaying purchase and installation of the christmas tree and the flow lines until installation of the production platform. Savings are also realized from the reduction in the number of spare parts and tools. Moreover, the savings related to improved operations exceed considerably those from equipment acquisition and storage. Thus, the greatest benefit is the operational flexibility. The paper discusses initial standards, the subsea programs, philosophy, implementation, diver-assisted trees, diverless trees, and economics.

  6. Titian: Data Provenance Support in Spark

    PubMed Central

    Interlandi, Matteo; Shah, Kshitij; Tetali, Sai Deep; Gulzar, Muhammad Ali; Yoo, Seunghyun; Kim, Miryung; Millstein, Todd; Condie, Tyson

    2015-01-01

    Debugging data processing logic in Data-Intensive Scalable Computing (DISC) systems is a difficult and time consuming effort. Today’s DISC systems offer very little tooling for debugging programs, and as a result programmers spend countless hours collecting evidence (e.g., from log files) and performing trial and error debugging. To aid this effort, we built Titian, a library that enables data provenance—tracking data through transformations—in Apache Spark. Data scientists using the Titian Spark extension will be able to quickly identify the input data at the root cause of a potential bug or outlier result. Titian is built directly into the Spark platform and offers data provenance support at interactive speeds—orders-of-magnitude faster than alternative solutions—while minimally impacting Spark job performance; observed overheads for capturing data lineage rarely exceed 30% above the baseline job execution time. PMID:26726305

  7. Evolution of Decision Rules Used for IT Portfolio Management: An Inductive Approach

    NASA Astrophysics Data System (ADS)

    Karhade, Prasanna P.; Shaw, Michael J.; Subramanyam, Ramanath

    IT portfolio management and the related planning decisions for IT-dependent initiatives are critical to organizational performance. Building on the logic of appropriateness theoretical framework, we define an important characteristic of decision rules used during IT portfolio planning; rule appropriateness with regards to the risk-taking criterion. We propose that rule appropriateness will be an important factor explaining the evolution of rules over time. Using an inductive learning methodology, we analyze a unique dataset of actual IT portfolio planning decisions spanning two consecutive years within one organization. We present systematic comparative analysis of the evolution of rules used in planning over two years to validate our research proposition. We find that rules that were inappropriate in the first year are being redefined to design appropriate rules for use in the second year. Our work provides empirical evidence demonstrating organizational learning and improvements in IT portfolio planning capabilities.

  8. Two-Dimensional Metal Dichalcogenides and Oxides for Hydrogen Evolution: A Computational Screening Approach.

    PubMed

    Pandey, Mohnish; Vojvodic, Aleksandra; Thygesen, Kristian S; Jacobsen, Karsten W

    2015-05-01

    We explore the possibilities of hydrogen evolution by basal planes of 2D metal dichalcogenides and oxides in the 2H and 1T class of structures using the hydrogen binding energy as a computational activity descriptor. For some groups of systems like the Ti, Zr, and Hf dichalcogenides the hydrogen bonding to the 2H structure is stronger than that to the 1T structure, while for the Cr, Mo, and W dichalcogenides the behavior is opposite. This is rationalized by investigating shifts in the chalcogenide p levels comparing the two structures. We find that usually for a given material only at most one of the two phases will be active for the hydrogen evolution reaction; however, in most cases the two phases are very close in formation energy, opening up the possibility for stabilizing the active phase. The study points to many new possible 2D HER materials beyond the few that are already known. PMID:26263317

  9. Sobolev gradient approach for the time evolution related to energy minimization of Ginzburg-Landau functionals

    NASA Astrophysics Data System (ADS)

    Raza, Nauman; Sial, Sultan; Siddiqi, Shahid S.

    2009-04-01

    The Sobolev gradient technique has been discussed previously in this journal as an efficient method for finding energy minima of certain Ginzburg-Landau type functionals [S. Sial, J. Neuberger, T. Lookman, A. Saxena, Energy minimization using Sobolev gradients: application to phase separation and ordering, J. Comput. Phys. 189 (2003) 88-97]. In this article a Sobolev gradient method for the related time evolution is discussed.

  10. Future of DAQ Frameworks and Approaches, and Their Evolution towards the Internet of Things

    NASA Astrophysics Data System (ADS)

    Neufeld, Niko

    2015-12-01

    Nowadays, a DAQ system is a complex network of processors, sensors and many other active devices. Historically, providing a framework for DAQ has been a very important role of host institutes of experiments. Reviewing evolution of such DAQ frameworks is a very interesting subject of the conference. “Internet of Things” is a recent buzz word but a DAQ framework could be a good example of IoT.

  11. Spatial Autocatalytic Dynamics: An Approach to Modeling Prebiotic Evolution. Chapter 1

    NASA Technical Reports Server (NTRS)

    Stassinopoulos, Dimitris; Colombano, Silvano P.; Lohn , Jason D.; Haith, Gary L.; Scargle, Jeffrey; Liang, Shoudan; Lee, T. K.

    1999-01-01

    This paper addresses the origin of robust and evolvable metabolic functions, and the conditions under which it took place. We propose that spatial considerations, traditionally ignored, are essential to answering these important questions in prebiotic evolution. Our probabilistic cellular automaton model, based on work on autocatalytic metabolisms by Eigen, Kauffman, and others, has biologically interesting dynamical behavior that is missed if spatial extension is ignored.

  12. Modeling the evolution of natural cliffs subject to weathering: 1. Limit analysis approach

    NASA Astrophysics Data System (ADS)

    Utili, S.; Crosta, G. B.

    2011-03-01

    Retrogressive landsliding evolution of natural slopes subjected to weathering has been modeled by assuming Mohr-Coulomb material behavior and by using an analytical method. The case of weathering-limited slope conditions, with complete erosion of the accumulated debris, has been modeled. The limit analysis upper-bound method is used to study slope instability induced by a homogeneous decrease of material strength in space and time. The only assumption required in the model concerns the degree of weathering within the slope, and for this we assumed and tested different weathering laws. By means of this method, the evolution of cliffs subject to strong weathering conditions (weathering-limited conditions) was predicted. The discrete succession of failures taking place was modeled taking into account the geometry assumed by slopes as a consequence of previous mass movements. The results have been compared with published data from long-term slope monitoring and show a good match between experimental observations and analytical predictions. The retrogressive evolution of the slope occurs with decreasing size of the unstable blocks, following a logarithmic volume-frequency relationship. A nonlinear relationship is found between mass flux and average slope gradient. A set of normalized solutions is presented both by nomograms and tables for different values of slope angle, cohesion, and internal friction angle.

  13. Evolution of a Community-Based Participatory Approach in a Rural and Remote Dementia Care Research Program

    PubMed Central

    Morgan, Debra; Crossley, Margaret; Stewart, Norma; Kirk, Andrew; Forbes, Dorothy; D’Arcy, Carl; Dal Bello-Haas, Vanina; McBain, Lesley; O’Connell, Megan; Bracken, Joanne; Kosteniuk, Julie; Cammer, Allison

    2015-01-01

    Background Community-based participatory research (CBPR) approaches are valuable strategies for addressing complex health and social problems and powerful tools to support effective transformation of social and health policy to better meet the needs of diverse stakeholders. Objectives Since 1997, our team has utilized CBPR approaches to improve health service delivery for persons with dementia and their caregivers in rural and remote settings. We describe the evolution of our approach, including benefits, challenges, and lessons learned over the last 15 years. Methods A multistage approach initiated an ongoing CBPR research program in rural dementia care and shaped its direction based on stakeholders’ recommendation to prioritize both community and facility-based care. Strategies to develop and foster collaborative partnerships have included travel to rural and remote regions, province-wide community meetings, stakeholder workshops, creation of a Decision-Maker Advisory Council to provide ongoing direction to the overall program, development of diverse project-specific advisory groups, and a highly successful and much anticipated annual knowledge exchange and team-building event. Lessons Learned Partnering with stakeholders in the full research process has enhanced the research quality, relevance, application, and sustainability. These benefits have supported the team’s evolution from a relatively traditional focus to an integrated approach guiding all aspects of our research. Conclusions Developing and sustaining the full range of stakeholder and decision-maker partnerships is resource-and time-intensive, but our experience shows that community-based participatory strategies are highly suited to health services research that is designed to support sustainable service delivery improvements. PMID:25435560

  14. Mode and tempo in the evolution of socio-political organization: reconciling 'Darwinian' and 'Spencerian' evolutionary approaches in anthropology.

    PubMed

    Currie, Thomas E; Mace, Ruth

    2011-04-12

    Traditional investigations of the evolution of human social and political institutions trace their ancestry back to nineteenth century social scientists such as Herbert Spencer, and have concentrated on the increase in socio-political complexity over time. More recent studies of cultural evolution have been explicitly informed by Darwinian evolutionary theory and focus on the transmission of cultural traits between individuals. These two approaches to investigating cultural change are often seen as incompatible. However, we argue that many of the defining features and assumptions of 'Spencerian' cultural evolutionary theory represent testable hypotheses that can and should be tackled within a broader 'Darwinian' framework. In this paper we apply phylogenetic comparative techniques to data from Austronesian-speaking societies of Island South-East Asia and the Pacific to test hypotheses about the mode and tempo of human socio-political evolution. We find support for three ideas often associated with Spencerian cultural evolutionary theory: (i) political organization has evolved through a regular sequence of forms, (ii) increases in hierarchical political complexity have been more common than decreases, and (iii) political organization has co-evolved with the wider presence of hereditary social stratification. PMID:21357233

  15. Coastline evolution of Portuguese low-lying sandy coast in the last 50 years: an integrated approach

    NASA Astrophysics Data System (ADS)

    Ponte Lira, Cristina; Nobre Silva, Ana; Taborda, Rui; Freire de Andrade, Cesar

    2016-06-01

    Regional/national-scale information on coastline rates of change and trends is extremely valuable, but these studies are scarce. A widely accepted standardized methodology for analysing long-term coastline change has been difficult to achieve, but it is essential to conduct an integrated and holistic approach to coastline evolution and hence support coastal management actions. Additionally, databases providing knowledge on coastline evolution are of key importance to support both coastal management experts and users.The main objective of this work is to present the first systematic, national-scale and consistent long-term coastline evolution data of Portuguese mainland low-lying sandy coasts.The methodology used quantifies coastline evolution using a unique and robust coastline indicator (the foredune toe), which is independent of short-term changes.The dataset presented comprises (1) two polyline sets, mapping the 1958 and 2010 sandy beach-dune system coastline, both optimized for working at 1 : 50 000 scale or smaller; (2) one polyline set representing long-term change rates between 1958 and 2010, each estimated at 250 m; and (3) a table with minimum, maximum and mean of evolution rates for sandy beach-dune system coastline. All science data produced here are openly accessible at https://doi.pangaea.de/10.1594/PANGAEA.859136 and can be used in other studies.Results show beach erosion as the dominant trend, with a mean change rate of -0.24 ± 0.01 m year-1 for all mainland Portuguese beach-dune systems. Although erosion is dominant, this evolution is variable in signal and magnitude in different coastal sediment cells and also within each cell. The most relevant beach erosion issues were found in the coastal stretches of Espinho-Torreira and Costa Nova-Praia de Mira, Cova da Gala-Leirosa, and Cova do Vapor-Costa da Caparica. The coastal segments Minho River-Nazaré and Costa da Caparica

  16. Scientific Workflows + Provenance = Better (Meta-)Data Management

    NASA Astrophysics Data System (ADS)

    Ludaescher, B.; Cuevas-Vicenttín, V.; Missier, P.; Dey, S.; Kianmajd, P.; Wei, Y.; Koop, D.; Chirigati, F.; Altintas, I.; Belhajjame, K.; Bowers, S.

    2013-12-01

    The origin and processing history of an artifact is known as its provenance. Data provenance is an important form of metadata that explains how a particular data product came about, e.g., how and when it was derived in a computational process, which parameter settings and input data were used, etc. Provenance information provides transparency and helps to explain and interpret data products. Other common uses and applications of provenance include quality control, data curation, result debugging, and more generally, 'reproducible science'. Scientific workflow systems (e.g. Kepler, Taverna, VisTrails, and others) provide controlled environments for developing computational pipelines with built-in provenance support. Workflow results can then be explained in terms of workflow steps, parameter settings, input data, etc. using provenance that is automatically captured by the system. Scientific workflows themselves provide a user-friendly abstraction of the computational process and are thus a form of ('prospective') provenance in their own right. The full potential of provenance information is realized when combining workflow-level information (prospective provenance) with trace-level information (retrospective provenance). To this end, the DataONE Provenance Working Group (ProvWG) has developed an extension of the W3C PROV standard, called D-PROV. Whereas PROV provides a 'least common denominator' for exchanging and integrating provenance information, D-PROV adds new 'observables' that described workflow-level information (e.g., the functional steps in a pipeline), as well as workflow-specific trace-level information ( timestamps for each workflow step executed, the inputs and outputs used, etc.) Using examples, we will demonstrate how the combination of prospective and retrospective provenance provides added value in managing scientific data. The DataONE ProvWG is also developing tools based on D-PROV that allow scientists to get more mileage from provenance metadata

  17. Assessing the Impact of Landscape Evolution on Carbon Dynamics: A Coupled Physically-Based Modelling Approach

    NASA Astrophysics Data System (ADS)

    Dialynas, Y. G.; Bastola, S.; Billings, S. A.; Bras, R. L.

    2014-12-01

    Soil erosion and deposition play an important role in the global carbon (C) cycle, constituting an important driver of atmospheric CO2. Clarification of the net effect of landscape evolution on the C cycle may be achieved using coupled fully-distributed modelling of hydro-geomorphic and biogeochemical processes. We developed a distributed model of soil organic C (SOC) dynamics within an existing coupled physically-based hydro-geomorphic model (tRIBS - Erosion) to simulate the effects of soil erosion and deposition on C dynamics at basin scale. The SOC mass balance is analytically formulated at each cell using temporally variant, continuous vertical profiles of SOC content and SOC production and oxidation rate constants derived from SOC turnover characteristics. Landscape evolution feedbacks on C dynamics include the redistribution of eroded SOC, and the alteration of the SOC production and oxidation throughout the corresponding vertical profiles due to geomorphic perturbations. At each time step, model outputs include lateral and vertical C fluxes, and SOC content, at each soil column. We applied the model to the Calhoun Experimental Forest in South Carolina, which constitutes a forest recovering from agricultural land degradation prior to the mid-20th century. To test performance we carried out a point comparison against a spreadsheet-based model, SOrCERO (Soil Organic Carbon, Erosion, Replacement, and Oxidation) of SOC dynamics, which estimates effects of SOC erosion and altered SOC production and oxidation on CO2 release at an eroding profile. At a point, time integrated results from the two models were comparable. The proposed model has the additional advantage of being able to quantify C sinks and sources across the landscape in a spatially explicit manner, by systematically accounting for topographic controls on C dynamics. Sensitivity analysis suggested that the alteration of SOC production and oxidation due to landscape evolution and management practices

  18. Lithofacies control in detrital zircon provenance studies: Insights from the Cretaceous Methow basin, southern Canadian Cordillera

    USGS Publications Warehouse

    DeGraaff-Surpless, K.; Mahoney, J.B.; Wooden, J.L.; McWilliams, M.O.

    2003-01-01

    High-frequency sampling for detrital zircon analysis can provide a detailed record of fine-scale basin evolution by revealing the temporal and spatial variability of detrital zircon ages within clastic sedimentary successions. This investigation employed detailed sampling of two sedimentary successions in the Methow/Methow-Tyaughton basin of the southern Canadian Cordillera to characterize the heterogeneity of detrital zircon signatures within single lithofacies and assess the applicability of detrital zircon analysis in distinguishing fine-scale provenance changes not apparent in lithologic analysis of the strata. The Methow/Methow-Tyaughton basin contains two distinct stratigraphic sequences of middle Albian to Santonian clastic sedimentary rocks: submarine-fan deposits of the Harts Pass Formation/Jackass Mountain Group and fluvial deposits of the Winthrop Formation. Although both stratigraphic sequences displayed consistent ranges in detrital zircon ages on a broad scale, detailed sampling within each succession revealed heterogeneity in the detrital zircon age distributions that was systematic and predictable in the turbidite succession but unpredictable in the fluvial succession. These results suggest that a high-density sampling approach permits interpretation of finescale changes within a lithologically uniform turbiditic sedimentary succession, but heterogeneity within fluvial systems may be too large and unpredictable to permit accurate fine-scale characterization of the evolution of source regions. The robust composite detrital zircon age signature developed for these two successions permits comparison of the Methow/Methow-Tyaughton basin age signature with known plutonic source-rock ages from major plutonic belts throughout the Cretaceous North American margin. The Methow/Methow-Tyaughton basin detrital zircon age signature matches best with source regions in the southern Canadian Cordillera, requiring that the basin developed in close proximity to the

  19. Hydrochemical evolution and groundwater flow processes in the Galilee and Eromanga basins, Great Artesian Basin, Australia: a multivariate statistical approach.

    PubMed

    Moya, Claudio E; Raiber, Matthias; Taulis, Mauricio; Cox, Malcolm E

    2015-03-01

    The Galilee and Eromanga basins are sub-basins of the Great Artesian Basin (GAB). In this study, a multivariate statistical approach (hierarchical cluster analysis, principal component analysis and factor analysis) is carried out to identify hydrochemical patterns and assess the processes that control hydrochemical evolution within key aquifers of the GAB in these basins. The results of the hydrochemical assessment are integrated into a 3D geological model (previously developed) to support the analysis of spatial patterns of hydrochemistry, and to identify the hydrochemical and hydrological processes that control hydrochemical variability. In this area of the GAB, the hydrochemical evolution of groundwater is dominated by evapotranspiration near the recharge area resulting in a dominance of the Na-Cl water types. This is shown conceptually using two selected cross-sections which represent discrete groundwater flow paths from the recharge areas to the deeper parts of the basins. With increasing distance from the recharge area, a shift towards a dominance of carbonate (e.g. Na-HCO3 water type) has been observed. The assessment of hydrochemical changes along groundwater flow paths highlights how aquifers are separated in some areas, and how mixing between groundwater from different aquifers occurs elsewhere controlled by geological structures, including between GAB aquifers and coal bearing strata of the Galilee Basin. The results of this study suggest that distinct hydrochemical differences can be observed within the previously defined Early Cretaceous-Jurassic aquifer sequence of the GAB. A revision of the two previously recognised hydrochemical sequences is being proposed, resulting in three hydrochemical sequences based on systematic differences in hydrochemistry, salinity and dominant hydrochemical processes. The integrated approach presented in this study which combines different complementary multivariate statistical techniques with a detailed assessment of the

  20. Managing the Evolution of an Enterprise Architecture using a MAS-Product-Line Approach

    NASA Technical Reports Server (NTRS)

    Pena, Joaquin; Hinchey, Michael G.; Resinas, manuel; Sterritt, Roy; Rash, James L.

    2006-01-01

    We view an evolutionary system ns being n software product line. The core architecture is the unchanging part of the system, and each version of the system may be viewed as a product from the product line. Each "product" may be described as the core architecture with sonre agent-based additions. The result is a multiagent system software product line. We describe an approach to such n Software Product Line-based approach using the MaCMAS Agent-Oriented nzethoclology. The approach scales to enterprise nrchitectures as a multiagent system is an approprinre means of representing a changing enterprise nrchitectclre nnd the inferaction between components in it.

  1. Modeling the evolution of lithium-ion particle contact distributions using a fabric tensor approach

    DOE PAGESBeta

    Stershic, Andrew; Simunovic, Srdjan; Nanda, Jagjit

    2015-01-01

    Electrode microstructure and processing can strongly influence lithium-ion battery performance such as capacity retention, power, and rate. Battery electrodes are multi-phase composite structures wherein conductive diluents and binder bond active material to a current collector. The structure and response of this composite network during repeated electrochemical cycling directly affects battery performance characteristics. We propose the fabric tensor formalism for describing the structure and evolution of the electrode microstructure. Fabric tensors are directional measures of particulate assemblies based on inter-particle connectivity, relating to the structural and transport properties of the electrode. Fabric tensor analysis is applied to experimental data-sets for positivemore » electrode made of lithium nickel manganese cobalt oxide, captured by X-ray tomography for several compositions and consolidation pressures. We show that fabric tensors capture the evolution of inter-particle contact distribution and are therefore good measures for the internal state of and electronic transport within the electrode. The fabric tensor analysis is also applied to Discrete Element Method (DEM) simulations of electrode microstructures using spherical particles with size distributions from the tomography. These results do not follow the experimental trends, which indicates that the particle size distribution alone is not a sufficient measure for the electrode microstructures in DEM simulations.« less

  2. Controversy in Biology Classrooms-Citizen Science Approaches to Evolution and Applications to Climate Change Discussions.

    PubMed

    Yoho, Rachel A; Vanmali, Binaben H

    2016-03-01

    The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to "hot topics" of socioscientific debate based on our review of the findings of other authors. Journal of Microbiology & Biology Education. PMID:27047604

  3. Microbial experimental evolution as a novel research approach in the Vibrionaceae and squid-Vibrio symbiosis

    PubMed Central

    Soto, William; Nishiguchi, Michele K.

    2014-01-01

    The Vibrionaceae are a genetically and metabolically diverse family living in aquatic habitats with a great propensity toward developing interactions with eukaryotic microbial and multicellular hosts (as either commensals, pathogens, and mutualists). The Vibrionaceae frequently possess a life history cycle where bacteria are attached to a host in one phase and then another where they are free from their host as either part of the bacterioplankton or adhered to solid substrates such as marine sediment, riverbeds, lakebeds, or floating particulate debris. These two stages in their life history exert quite distinct and separate selection pressures. When bound to solid substrates or to host cells, the Vibrionaceae can also exist as complex biofilms. The association between bioluminescent Vibrio spp. and sepiolid squids (Cephalopoda: Sepiolidae) is an experimentally tractable model to study bacteria and animal host interactions, since the symbionts and squid hosts can be maintained in the laboratory independently of one another. The bacteria can be grown in pure culture and the squid hosts raised gnotobiotically with sterile light organs. The partnership between free-living Vibrio symbionts and axenic squid hatchlings emerging from eggs must be renewed every generation of the cephalopod host. Thus, symbiotic bacteria and animal host can each be studied alone and together in union. Despite virtues provided by the Vibrionaceae and sepiolid squid-Vibrio symbiosis, these assets to evolutionary biology have yet to be fully utilized for microbial experimental evolution. Experimental evolution studies already completed are reviewed, along with exploratory topics for future study. PMID:25538686

  4. Modeling the evolution of lithium-ion particle contact distributions using a fabric tensor approach

    NASA Astrophysics Data System (ADS)

    Stershic, A. J.; Simunovic, S.; Nanda, J.

    2015-11-01

    Electrode microstructure and processing can strongly influence lithium-ion battery performance such as capacity retention, power, and rate. Battery electrodes are multi-phase composite structures wherein conductive diluents and binder bond active material to a current collector. The structure and response of this composite network during repeated electrochemical cycling directly affects battery performance characteristics. We propose the fabric tensor formalism for describing the structure and evolution of the electrode microstructure. Fabric tensors are directional measures of particulate assemblies based on inter-particle connectivity, relating to the structural and transport properties of the electrode. Fabric tensor analysis is applied to experimental data-sets for positive electrode made of lithium nickel manganese cobalt oxide, captured by X-ray tomography for several compositions and consolidation pressures. We show that fabric tensors capture the evolution of inter-particle contact distribution and are therefore good measures for the internal state of and electronic transport within the electrode. The fabric tensor analysis is also applied to Discrete Element Method (DEM) simulations of electrode microstructures using spherical particles with size distributions from the tomography. These results do not follow the experimental trends, which indicates that the particle size distribution alone is not a sufficient measure for the electrode microstructures in DEM simulations.

  5. Conceptual and empirical problems with game theoretic approaches to language evolution

    PubMed Central

    Watumull, Jeffrey; Hauser, Marc D.

    2014-01-01

    The importance of game theoretic models to evolutionary theory has been in formulating elegant equations that specify the strategies to be played and the conditions to be satisfied for particular traits to evolve. These models, in conjunction with experimental tests of their predictions, have successfully described and explained the costs and benefits of varying strategies and the dynamics for establishing equilibria in a number of evolutionary scenarios, including especially cooperation, mating, and aggression. Over the past decade or so, game theory has been applied to model the evolution of language. In contrast to the aforementioned scenarios, however, we argue that these models are problematic due to conceptual confusions and empirical difficiences. In particular, these models conflate the comptutations and representations of our language faculty (mechanism) with its utility in communication (function); model languages as having different fitness functions for which there is no evidence; depend on assumptions for the starting state of the system, thereby begging the question of how these systems evolved; and to date, have generated no empirical studies at all. Game theoretic models of language evolution have therefore failed to advance how or why language evolved, or why it has the particular representations and computations that it does. We conclude with some brief suggestions for how this situation might be ameliorated, enabling this important theoretical tool to make substantive empirical contributions. PMID:24678305

  6. Conceptual and empirical problems with game theoretic approaches to language evolution.

    PubMed

    Watumull, Jeffrey; Hauser, Marc D

    2014-01-01

    The importance of game theoretic models to evolutionary theory has been in formulating elegant equations that specify the strategies to be played and the conditions to be satisfied for particular traits to evolve. These models, in conjunction with experimental tests of their predictions, have successfully described and explained the costs and benefits of varying strategies and the dynamics for establishing equilibria in a number of evolutionary scenarios, including especially cooperation, mating, and aggression. Over the past decade or so, game theory has been applied to model the evolution of language. In contrast to the aforementioned scenarios, however, we argue that these models are problematic due to conceptual confusions and empirical difficiences. In particular, these models conflate the comptutations and representations of our language faculty (mechanism) with its utility in communication (function); model languages as having different fitness functions for which there is no evidence; depend on assumptions for the starting state of the system, thereby begging the question of how these systems evolved; and to date, have generated no empirical studies at all. Game theoretic models of language evolution have therefore failed to advance how or why language evolved, or why it has the particular representations and computations that it does. We conclude with some brief suggestions for how this situation might be ameliorated, enabling this important theoretical tool to make substantive empirical contributions. PMID:24678305

  7. Controversy in Biology Classrooms—Citizen Science Approaches to Evolution and Applications to Climate Change Discussions

    PubMed Central

    Yoho, Rachel A.; Vanmali, Binaben H.

    2016-01-01

    The biological sciences encompass topics considered controversial by the American public, such as evolution and climate change. We believe that the development of climate change education in the biology classroom is better informed by an understanding of the history of the teaching of evolution. A common goal for science educators should be to engender a greater respect for and appreciation of science among students while teaching specific content knowledge. Citizen science has emerged as a viable yet underdeveloped method for engaging students of all ages in key scientific issues that impact society through authentic data-driven scientific research. Where successful, citizen science may open avenues of communication and engagement with the scientific process that would otherwise be more difficult to achieve. Citizen science projects demonstrate versatility in education and the ability to test hypotheses by collecting large amounts of often publishable data. We find a great possibility for science education research in the incorporation of citizen science projects in curriculum, especially with respect to “hot topics” of socioscientific debate based on our review of the findings of other authors. Journal of Microbiology & Biology Education PMID:27047604

  8. Evolution, Interaction, and Intrinsic Properties of Dislocations in Intermetallics: Anisotropic 3D Dislocation Dynamics Approach

    SciTech Connect

    Qian Chen

    2008-08-18

    The generation, motion, and interaction of dislocations play key roles during the plastic deformation process of crystalline solids. 3D Dislocation Dynamics has been employed as a mesoscale simulation algorithm to investigate the collective and cooperative behavior of dislocations. Most current research on 3D Dislocation Dynamics is based on the solutions available in the framework of classical isotropic elasticity. However, due to some degree of elastic anisotropy in almost all crystalline solids, it is very necessary to extend 3D Dislocation Dynamics into anisotropic elasticity. In this study, first, the details of efficient and accurate incorporation of the fully anisotropic elasticity into 3D discrete Dislocation Dynamics by numerically evaluating the derivatives of Green's functions are described. Then the intrinsic properties of perfect dislocations, including their stability, their core properties and disassociation characteristics, in newly discovered rare earth-based intermetallics and in conventional intermetallics are investigated, within the framework of fully anisotropic elasticity supplemented with the atomistic information obtained from the ab initio calculations. Moreover, the evolution and interaction of dislocations in these intermetallics as well as the role of solute segregation are presented by utilizing fully anisotropic 3D dislocation dynamics. The results from this work clearly indicate the role and the importance of elastic anisotropy on the evolution of dislocation microstructures, the overall ductility and the hardening behavior in these systems.

  9. On Estimating Provenances of Lunar Highland Materials

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.; Jolliff, Brad L.

    1998-01-01

    That even relatively small impacts can spread material across the face of the Moon is evident from the rays of Tycho. Tycho ejecta triggered the landslide that produced the light mantle deposit at Apollo 17 and perhaps excavated the Central Valley craters there. Basin-sized impacts appear to follow the same scaling laws as smaller impacts, as indicated by the satisfaction of a geophysical model. These giant impacts rearranged huge amounts of premare material, complicating the determination of provenance of materials collected from the highlands. We have developed a model to estimate the probability that material at a particular location might derive from a given basin or large crater. This model is based on crater scaling laws, and effects of secondary cratering. Because it accounts for the volume of primary ejecta from the basin-forming transient craters and the excavating and mixing effects of these ejecta with the substrate onto which they fall, it gives much thicker deposits than an early work. Our modeling takes into account the distribution of sizes of primary ejecta fragments (PriFrags) to obtain the probability at a given site for a deposit of a particular thickness and with a fraction of PriFrags.

  10. Mineralogical and geochemical evidence of Quachita provenance

    SciTech Connect

    Sutton, S.J. . Dept. of Earth Resources); Land, L.S.; Hutson, F. . Dept. of Geological Science); Awwiller, D.N. . Dept. of Geology)

    1994-03-01

    Provenance of the extremely thick Ouachita flysch has not been specifically identified, despite several recent studies. Detrital mineral compositions, Sm-Nd model ages, and single zircon dates strongly suggest that several sources contributed sediment that became well-mixed before deposition. Sm-Nd model ages are nearly uniform for flysch samples, regardless of geographic position or exact stratigraphic position. These ages appear to rule out significant contribution by a Paleozoic island arc, and suggest a single source, multiple sources with similar model ages, or thorough mixing of sources with different model ages. In contrast, single zircon ages are variable, including Archean, Proterozoic, and Paleozoic ages. These ages indicate multiple sediment sources, including some external to North America. The zircon ages, however, may not be generally representative of Ouachita sediment sources because they were obtained on zircons far larger than typical Ouachita detrital zircons. The Sm-Nd model ages and single zircon ages can both be explained if sediment entering the Ouachita Trough came from multiple sources, but was already thoroughly mixed before entering the trough. Such mixing is also suggested by detrital mineral analyses. Muscovite, garnet, and tourmaline have been analyzed.

  11. Provenance of Norphlet sandstone, northern Gulf Coast

    SciTech Connect

    Ryan, W.P.; Ward, W.C.; Kuglar, R.L.

    1987-09-01

    The Upper Jurassic Norphlet sandstone of the northern Gulf Coast is predominantly subarkose, with some arkose in the eastern area and sublitharenite and quartzarenite in the western area. Despite great depths of burial and despite feldspar and rock-fragment constituents, diagenesis has not appreciably altered the composition of Norphlet sandstone. Therefore, reconstruction of original composition of Norphlet sandstone presented little difficulty. Variation in detrital modes of the Norphlet suggests compositionally distinct source terranes. Samples from Florida, Alabama, and Mississippi reflect the influence of metamorphic and plutonic rocks of the Appalachian Piedmont Province and of Triassic-Jurassic volcanic rocks. Sandstones in east Texas, northern Louisiana, and southern Arkansas were derived from sedimentary and metasedimentary rocks of the Ouachita system. The Arbuckle Mountains and Llano uplift may have supplied trace amounts of quartzo-feldspathic and volcanic-rock fragments to the extreme western part of the study area. Norphlet sandstones represent a mixture of collision-orogen-derived sediment from the Appalachian and/or Ouachita system and continental-block-derived sediment from paleohighs and uplifts within the Gulf basin. However, Norphlet sandstones plot in the craton-interior and transitional-continental fields on Q-F-L and QM-F-Lt tectonic-provenance diagrams, because of mineralogically mature source rocks, elimination of unstable grains by abrasion and sorting during deposition, and/or sediment mixing from different source terranes.

  12. Modern high spatial resolution approaches to crustal evolution studies - pitfalls and progress

    NASA Astrophysics Data System (ADS)

    Whitehouse, M. J.

    2012-12-01

    Developments in analytical techniques for in situ geochronology and isotope geochemistry over the past few decades have contributed greatly to our understanding of the processes of Precambrian crustal evolution, plate tectonics, the development of Earth's hydrosphere and atmosphere and conditions for the development of life on Earth. The further back in time we go, however, the more complex the geology, requiring that we unravel and/or try to see through multiple phases of disturbance. Such geological complexity complicates interpretation and can lead to conflicting viewpoints on such key questions as when plate tectonics began on Earth, when it evolved to a process essentially similar to that of today and the nature and habitability of a potentially pre-plate tectonic Earth in the Hadean. This presentation will review, with case studies, some of the crucial aspects of applying and interpreting high spatial resolution in situ methods and some of the potential pitfalls. Obtaining accurate and precise geochronology is an essential first step in any study of Precambrian geology, whether it is the primary goal or provides a supporting framework to other diverse applications. To this end, high spatial resolution secondary ion mass spectrometry (SIMS) and laser ablation inductiively coupled plasma mass spectrometry (LA-ICPMS), typically combined with relevant imaging methods such as cathode luminescence (CL) are widely used to investigate the U-Pb systematics of complex zircon. In general precision is merely an analytical hurdle that we are good (and continually getting better) at clearing, but accuracy commonly contains not just an analytical element (e.g. calibration of standards) but also a considerable subjective element in order to unravel the commonly polyphase evolution of early Precambrian zircon. Examples of such problematic interpretations from the Neoarchean Lewisian Complex of northwest Scotland and the Paleoarchean Napier Complex of Antarctica will be

  13. Molecular Corridor Based Approach for Description of Evolution of Secondary Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Li, Y., Sr.; Poeschl, U.; Shiraiwa, M.

    2015-12-01

    Organic aerosol is ubiquitous in the atmosphere and its major component is secondary organic aerosol (SOA). Formation and evolution of SOA is a complex process involving coupled chemical reactions and mass transport in the gas and particle phases (Shiraiwa et al., 2014). Current air quality models do not embody the full spectrum of reaction and transport processes, nor do they identify the dominant rate-limiting steps in SOA formation, resulting in the significant underprediction of observed SOA concentrations, which precludes reliable quantitative predictions of aerosols and their environmental impacts. Recently, it has been suggested that the SOA chemical evolution can be represented well by "molecular corridor" with a tight inverse correlation between molar mass and volatility of SOA oxidation products (Shiraiwa et al., 2014). Here we further analyzed the structure, molar mass and volatility of 31,000 unique organic compounds. These compounds include oxygenated organic compounds as well as nitrogen- and sulfur-containing organics such as amines, organonitrates, and organosulfates. Results show that most of those compounds fall into this two-dimensional (2-D) space, which is constrained by two boundary lines corresponding to the volatility of n -alkanes CnH2n+2 and sugar alcohols CnH2n+2On. A method to predict the volatility of nitrogen- and sulfur- containing compounds is developed based on those 31,000 organic compounds. It is shown that the volatility can be well predicted as a function of chemical composition numbers, providing a way to apply this 2-D space to organic compounds observed in real atmosphere. A comprehensive set of observation data from laboratory experiments, field campaigns and indoor measurements is mapped to the molecular corridor. This 2-D space can successfully grasp the properties of organic compounds formed in different atmospheric conditions. The molecular corridor represents a new framework in which chemical and physical properties as

  14. Deciphering the brittle evolution of SW Norway through a combined structural, mineralogical and geochronological approach

    NASA Astrophysics Data System (ADS)

    Scheiber, Thomas; Viola, Giulio; Fredin, Ola; Zwingmann, Horst; Wilkinson, Camilla Maya; Ganerød, Morgan

    2016-04-01

    SW Norway has experienced a complex brittle history after cessation of the Caledonian orogeny, and the recent discoveries of major hydrocarbon reserves in heavily fractured and weathered basement offshore SW Norway has triggered a renewed interest in understanding this complex tectonic evolution. In this contribution we present results from a multidisciplinary study combining lineament analysis, field work, paleo-stress inversion, mineralogical characterization and radiometric dating in the Bømlo area of SW Norway in order to develop a tectonic model for the brittle evolution of this important region. The study area mainly consists of the Rolvsnes granodiorite (U-Pb zircon age of ca. 466 Ma), which is devoid of penetrative ductile deformation features. The first identified brittle faults are muscovite-bearing top-to-the-NNW thrusts and E-W striking dextral strike-slip faults decorated with stretched biotite. These are mechanically compatible and are assigned to the same NNW-SSE transpressional regime. Ar-Ar muscovite and biotite dates of ca. 450 Ma (Late Ordovician) indicate fault activity in the course of a Taconian-equivalent orogenic event. During the subsequent Silurian Laurentia-Baltica collision variably oriented, lower-grade chlorite and epidote-coated faults formed in response to a ENE-WSW compressional stress regime. A large number of mainly N-S striking normal faults consist of variably thick fault gouge cores with illite, quartz, kaolinite, calcite and epidote mineralizations, accommodating mainly E-W extension. K-Ar dating of illites separated from representative fault gouges and zones of altered granodiorite constrain deformation ranging from the Permian to the Late Jurassic, indicating a long history of crustal extension where faults were repeatedly activated. In addition, a set of ca. SW-NE striking faults associated with alteration zones give Cretaceous dates, either representing a young phase of NW-SE extension or reactivation of previously formed

  15. The evolution and functions of laughter and humor: a synthetic approach.

    PubMed

    Gervais, Matthew; Wilson, David Sloan

    2005-12-01

    A number of recent hypotheses have attempted to explain the ultimate evolutionary origins of laughter and humor. However most of these have lacked breadth in their evolutionary frameworks while neglecting the empirical existence of two distinct types of laughter--Duchenne and non-Duchenne--and the implications of this distinction for the evolution of laughter as a signal. Most of these hypotheses have also been proposed in relative isolation of each other and remain disjointed from the relevant empirical literature. Here we attempt to remedy these shortcomings through a synthesis of previous laughter and humor research followed by (i) a reevaluation of this research in light of theory and data from several relevant disciplines, and (ii) the proposal of a synthetic evolutionary framework that takes into account phylogeny and history as well as proximate mechanisms and adaptive significance. We consider laughter to have been a preadaptation that was gradually elaborated and co-opted through both biological and cultural evolution. We hypothesize that Duchenne laughter became fully ritualized in early hominids between 4 and 2 mya as a medium for playful emotional contagion. This mechanism would have coupled the emotions of small hominid groups and promoted resource-building social play during the fleeting periods of safety and satiation that characterized early bipedal life. We further postulate that a generalized class of nonserious social incongruity would have been a reliable indicator of such safe times and thereby came to be a potent distal elicitor of laughter and playful emotion. This class of stimuli had its origins in primate social play and was the foundation for formal human humor. Within this framework, Duchenne laughter and protohumor were well established in the hominid biobehavioral repertoire when more cognitively sophisticated traits evolved in the hominid line between 2 mya and the present. The prior existence of laughter and humor allowed them to be

  16. Securing Provenance of Distributed Processes in an Untrusted Environment

    NASA Astrophysics Data System (ADS)

    Syalim, Amril; Nishide, Takashi; Sakurai, Kouichi

    Recently, there is much concern about the provenance of distributed processes, that is about the documentation of the origin and the processes to produce an object in a distributed system. The provenance has many applications in the forms of medical records, documentation of processes in the computer systems, recording the origin of data in the cloud, and also documentation of human-executed processes. The provenance of distributed processes can be modeled by a directed acyclic graph (DAG) where each node represents an entity, and an edge represents the origin and causal relationship between entities. Without sufficient security mechanisms, the provenance graph suffers from integrity and confidentiality problems, for example changes or deletions of the correct nodes, additions of fake nodes and edges, and unauthorized accesses to the sensitive nodes and edges. In this paper, we propose an integrity mechanism for provenance graph using the digital signature involving three parties: the process executors who are responsible in the nodes' creation, a provenance owner that records the nodes to the provenance store, and a trusted party that we call the Trusted Counter Server (TCS) that records the number of nodes stored by the provenance owner. We show that the mechanism can detect the integrity problem in the provenance graph, namely unauthorized and malicious “authorized” updates even if all the parties, except the TCS, collude to update the provenance. In this scheme, the TCS only needs a very minimal storage (linear with the number of the provenance owners). To protect the confidentiality and for an efficient access control administration, we propose a method to encrypt the provenance graph that allows access by paths and compartments in the provenance graph. We argue that encryption is important as a mechanism to protect the provenance data stored in an untrusted environment. We analyze the security of the integrity mechanism, and perform experiments to measure

  17. Dynamical evolution of the Oort cloud. I. A Monte Carlo simulation. II. A theoretical approach

    SciTech Connect

    Remy, F.; Mignard, F.

    1985-07-01

    A Monte Carlo model is used to trace the dynamical evolution of the Oort cloud of comets to its ultimate end. After a review of previous simulations, the necessity of considering perturbations of the aphelion distance because of passing stars, the density of passing stars, and the three-body problem of sun-star-comet is discussed. For convenience, the solar gravitation is assumed to be zero as a star passes. It is also assumed that the initial cometary distribution had a perihelion near the orbits of Uranus-Neptune. Six orbital elements are calculated to obtain orbital distributions for the population in the Oort cloud. The cloud is estimated to contain 10 trillion comets, which would satisfy the present apparition rate of new comets. 34 references.

  18. The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach

    NASA Technical Reports Server (NTRS)

    Jun, Byung-Il; Clarke, David A.; Norman, Michael L.

    1994-01-01

    We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.

  19. The evolution of cosmic-ray-mediated magnetohydrodynamic shocks: A two-fluid approach

    NASA Astrophysics Data System (ADS)

    Jun, Byung-Il; Clarke, David A.; Norman, Michael L.

    1994-07-01

    We study the shock structure and acceleration efficiency of cosmic-ray mediated Magnetohydrodynamic (MHD) shocks both analytically and numerically by using a two-fluid model. Our model includes the dynamical effect of magnetic fields and cosmic rays on a background thermal fluid. The steady state solution is derived by following the technique of Drury & Voelk (1981) and compared to numerical results. We explore the time evolution of plane-perpendicular, piston-driven shocks. From the results of analytical and numerical studies, we conclude that the mean magnetic field plays an important role in the structure and acceleration efficiency of cosmic-ray mediated MHD shocks. The acceleration of cosmic-ray particles becomes less efficient in the presence of strong magnetic pressure since the field makes the shock less compressive. This feature is more prominent at low Mach numbers than at high Mach numbers.

  20. Co-Evolution of Opinion and Strategy in Persuasion Dynamics:. AN Evolutionary Game Theoretical Approach

    NASA Astrophysics Data System (ADS)

    Ding, Fei; Liu, Yun; Li, Yong

    In this paper, a new model of opinion formation within the framework of evolutionary game theory is presented. The model simulates strategic situations when people are in opinion discussion. Heterogeneous agents adjust their behaviors to the environment during discussions, and their interacting strategies evolve together with opinions. In the proposed game, we take into account payoff discount to join a discussion, and the situation that people might drop out of an unpromising game. Analytical and emulational results show that evolution of opinion and strategy always tend to converge, with utility threshold, memory length, and decision uncertainty parameters influencing the convergence time. The model displays different dynamical regimes when we set differently the rule when people are at a loss in strategy.

  1. A multiscale approach to defect evolution in tungsten under helium irradiation

    NASA Astrophysics Data System (ADS)

    Valles, G.; Cazalilla, A. L.; Gonzalez, C.; Martin-Bragado, I.; Prada, A.; Iglesias, R.; Perlado, J. M.; Rivera, A.

    2015-06-01

    We have studied He irradiation in tungsten from a multiscale point of view: Density Functional Theory (DFT) to obtain the binding energies of He to vacancy clusters, Binary Collision Approximation (BCA) and Molecular Dynamics (MD) to produce defect cascades and Object Kinetic Monte Carlo (OKMC) to study their evolution in larger temporal and spatial scales. A comparison between BCA and MD cascades produced by PKA at different energies has been done at different temperatures: at high temperature and at high PKA energies the OKMC results clearly depend on the defect cascades. 625 keV pulsed He ion irradiation has been simulated with cascades obtained by means of BCA and MD. The results show that in the case of ion irradiation, BCA results can provide good OKMC results. However, in the case of neutron irradiation producing high energy PKAs, BCA cascades clearly overestimate the number of FPs, which may have a strong influence on the OKMC results.

  2. Shuttle-C auxiliary propulsion system certification approach and low-cost evolution concepts

    NASA Technical Reports Server (NTRS)

    Harsh, M. George; Benner, John; Garabetian, Antranig; Burg, Roger

    1991-01-01

    Shuttle-C provides NASA with a heavy-lift cargo capability that is a low-cost derivative of the current Space Shuttle. This system can deliver 80,000 to 140,000 pounds of payload to low earth orbit within 4 years of authority to proceed. Shuttle-C will share th existing Shuttle launch facilities at Kennedy Space Center (KSC). The Shuttle-C vehicle incorporates an auxiliary propulsion system (APS) which provides separation from the external tank (ET), orbit circularization, on-orbit attitude hold, and deorbit capability. The APS is derived from the Shuttle orbiter aft reaction control system (ARCS) and orbital maneuvering system (OMS) with the objective of achieving minimum life cycle cost for this expendable vehicle. The resulting APS system will be described, its plan for a minimum-cost flight certification utilizing a cold-flow test program explained, and low-cost evolution by component design modification and part substitution presented.

  3. Stream-piracy impact on the long-term evolution of the Meuse basin. Physical approach "modeling with GOLEM"

    NASA Astrophysics Data System (ADS)

    Benaichouche, A.; Stab, O.; Cojan, I.; Brulhet, J.; Tijani, M.; Tessier, B.

    2012-04-01

    Landscape evolution results of antagonistic processes. In the Paris basin (France): tectonic uplift seems to be globally balanced by river incision. But the dynamic equilibrium of the relief can be disturbed by other processes and singularities may appear. A remarkable example is observed in the Meuse basin (NE of France), where the river is actually perched at more than +50m above the surrounding valleys: the Marne valley to the west and the Moselle valley to the east. This special morphology is the result of several stream piracies (at the expense of the Meuse) which has interested numerous researchers since a long time (Davis 1895, Blache 1943, Lesson-Quinif 2001 & Le Roux Harmand 1997-2009…). The most important ones of these piracies are: 1) the well-known capture of the Haute-Moselle by a tributary of the Meurthe near Toul; 2) at the north-west, the capture of the river Aire by the Aisne. On-going evolution suggests that similar events can be expected in the long-term future. Where and when next streams piracies could occur, what consequences may be expected? Our approach is to simulate the dynamic evolution of the landscape with an improved version of GOLEM (Geomorphic / Orogenic Landscape Evolution Model - LEM), software developed by Tucker & Slingerland in 1994 (http://csdms.colorado.edu/wiki/Model:GOLEM). The LEM characterizes erosion by incorporating diffusion and advection equations whose parameters must be fixed, according to local conditions. First simulations for next millions years with « detachment-limited » mode, let us locate several potential captures of the Meuse river by tributaries of the Moselle, therefore inducing a complete reorganization of the hydrographic network. The results of the localizations agree with local topography/geometry analysis. The first capture induces the propagation of a knickpoint and a significant lowering of the upstream part of the Meuse's basin. Downstream of the capture, the orientation of the abandoned valley

  4. Structural and Stratigraphic Evolution of the Iberia and Newfoundland Rifted Margins: A Quantitative Modeling Approach

    NASA Astrophysics Data System (ADS)

    Mohn, G.; Karner, G. D.; Manatschal, G.; Johnson, C. A.

    2014-12-01

    Rifted margins develop generally through polyphased extensional events leading eventually to break-up. We investigate the spatial and temporal evolution of the Iberia-Newfoundland rifted margin from its Permian post-orogenic stage to early Cretaceous break-up. We have applied Quantitative Basin Analysis to integrate seismic stratigraphic interpretations and drill hole data of representative sections across the Iberia-Newfoundland margins with kinematic models for the thinning of the lithosphere and subsequent isostatic readjustment. Our goal is to predict the distribution of extension and thinning, environments of deposition, crustal structure and subsidence history as functions of space and time. The first sediments deposited on the Iberian continental crust were in response to Permian lithospheric thinning, associated with magmatic underplating and subsequent thermal re-equilibration of the lithosphere. During late Triassic-early Jurassic rifting, a broadly distributed depth-independent lithospheric extension occurred, followed by late Jurassic rifting that increasingly focused with time and became depth-dependent during the early Cretaceous. However, there exists a temporality in the along-strike deformation of the Iberia-Newfoundland margin: significant Valanginian-Hauterivian deformation characterizes the northern Galicia Bank-Flemish Cap while the southern Iberian-Newfoundland region is characterized by Tithonian-early Berriasian extension. Deformation localized with time on both margins leading to late Aptian break-up. To match the distribution and magnitude of subsidence across the profiles requires significant thinning of middle/lower crustal level and subcontinental lithospheric mantle, leading to the formation of the hyper-extended domains. The late-stage deformation of both margins was characterized by a predominantly brittle deformation of the residual continental crust, leading to exhumation of subcontinental mantle and ultimately to seafloor

  5. Experimental Approach Reveals the Role of alx1 in the Evolution of the Echinoderm Larval Skeleton.

    PubMed

    Koga, Hiroyuki; Fujitani, Haruka; Morino, Yoshiaki; Miyamoto, Norio; Tsuchimoto, Jun; Shibata, Tomoko F; Nozawa, Masafumi; Shigenobu, Shuji; Ogura, Atsushi; Tachibana, Kazunori; Kiyomoto, Masato; Amemiya, Shonan; Wada, Hiroshi

    2016-01-01

    Over the course of evolution, the acquisition of novel structures has ultimately led to wide variation in morphology among extant multicellular organisms. Thus, the origins of genetic systems for new morphological structures are a subject of great interest in evolutionary biology. The larval skeleton is a novel structure acquired in some echinoderm lineages via the activation of the adult skeletogenic machinery. Previously, VEGF signaling was suggested to have played an important role in the acquisition of the larval skeleton. In the present study, we compared expression patterns of Alx genes among echinoderm classes to further explore the factors involved in the acquisition of a larval skeleton. We found that the alx1 gene, originally described as crucial for sea urchin skeletogenesis, may have also played an essential role in the evolution of the larval skeleton. Unlike those echinoderms that have a larval skeleton, we found that alx1 of starfish was barely expressed in early larvae that have no skeleton. When alx1 overexpression was induced via injection of alx1 mRNA into starfish eggs, the expression patterns of certain genes, including those possibly involved in skeletogenesis, were altered. This suggested that a portion of the skeletogenic program was induced solely by alx1. However, we observed no obvious external phenotype or skeleton. We concluded that alx1 was necessary but not sufficient for the acquisition of the larval skeleton, which, in fact, requires several genetic events. Based on these results, we discuss how the larval expression of alx1 contributed to the acquisition of the larval skeleton in the putative ancestral lineage of echinoderms. PMID:26866800

  6. Experimental Approach Reveals the Role of alx1 in the Evolution of the Echinoderm Larval Skeleton

    PubMed Central

    Koga, Hiroyuki; Fujitani, Haruka; Morino, Yoshiaki; Miyamoto, Norio; Tsuchimoto, Jun; Shibata, Tomoko F.; Nozawa, Masafumi; Shigenobu, Shuji; Ogura, Atsushi; Tachibana, Kazunori; Kiyomoto, Masato; Amemiya, Shonan; Wada, Hiroshi

    2016-01-01

    Over the course of evolution, the acquisition of novel structures has ultimately led to wide variation in morphology among extant multicellular organisms. Thus, the origins of genetic systems for new morphological structures are a subject of great interest in evolutionary biology. The larval skeleton is a novel structure acquired in some echinoderm lineages via the activation of the adult skeletogenic machinery. Previously, VEGF signaling was suggested to have played an important role in the acquisition of the larval skeleton. In the present study, we compared expression patterns of Alx genes among echinoderm classes to further explore the factors involved in the acquisition of a larval skeleton. We found that the alx1 gene, originally described as crucial for sea urchin skeletogenesis, may have also played an essential role in the evolution of the larval skeleton. Unlike those echinoderms that have a larval skeleton, we found that alx1 of starfish was barely expressed in early larvae that have no skeleton. When alx1 overexpression was induced via injection of alx1 mRNA into starfish eggs, the expression patterns of certain genes, including those possibly involved in skeletogenesis, were altered. This suggested that a portion of the skeletogenic program was induced solely by alx1. However, we observed no obvious external phenotype or skeleton. We concluded that alx1 was necessary but not sufficient for the acquisition of the larval skeleton, which, in fact, requires several genetic events. Based on these results, we discuss how the larval expression of alx1 contributed to the acquisition of the larval skeleton in the putative ancestral lineage of echinoderms. PMID:26866800

  7. Data Provenance Architecture for the Geosciences

    NASA Astrophysics Data System (ADS)

    Murphy, F.; Irving, D. H.

    2012-12-01

    The pace at which geoscientific insights inform societal development quickens with time and these insights drive decisions and actions of ever-increasing human and economic significance. Until recently academic, commercial and government bodies have maintained distinct bodies of knowledge to support scientific enquiry as well as societal development. However, it has become clear that the curation of the body of data is an activity of equal or higher social and commercial value. We address the community challenges in the curation of, access to, and analysis of scientific data including: the tensions between creators, providers and users; incentives and barriers to sharing; ownership and crediting. We also discuss the technical and financial challenges in maximising the return on the effort made in generating geoscientific data. To illustrate how these challenges might be addressed in the broader geoscientific domain, we describe the high-level data governance and analytical architecture in the upstream Oil Industry. This domain is heavily dependent on costly and highly diverse geodatasets collected and assimilated over timeframes varying from seconds to decades. These data must support both operational decisions at the minute-hour timefame and strategic and economic decisions of enterprise or national scale, and yet be sufficiently robust to last the life of a producing field. We develop three themes around data provenance, data ownership and business models for data curation. 1/ The overarching aspiration is to ensure that data provenance and quality is maintained along the analytical workflow. Hence if data on which a publication or report changes, the report and its publishers can be notified and we describe a mechanism by which dependent knowledge products can be flagged. 2/ From a cost and management point of view we look at who "owns" data especially in cases where the cost of curation and stewardship is significant compared to the cost of acquiring the data

  8. Geochemical provenance of Florida basement components

    SciTech Connect

    Heatherington, A.L.; Mueller, P.A. . Dept. of Geology); Dallmeyer, R.D. . Dept. of Geology)

    1993-03-01

    The pre-Cretaceous basement of Florida is generally considered to be exotic with respect to Proterozoic Laurentia. Paleontologic and paleomagnetic evidence have suggested a Gondwanan provenance for the Floridan basement, as either a peri-Gondwanide terrane or as a rifted block of the West African craton. The report of generally similar lithologic sequences and a record of similar Ar-Ar cooling ages in some Floridan and West African lithologic units has led to very specific correlations between these units. U-Pb, Sm-Nd, and Rb-Sr geochronologic studies as well as isotopic and elemental abundance data have been used to evaluate the validity of these correlations. Results indicate: (1) geochemical similarities between volcanic rocks of northeastern Florida and a Pan-African metavolcanic sequence (Niokola-Koba group) exposed in Senegal; (2) an absence of a Grenvillian-age (i.e., Laurentian) component in zircons separated from a Paleozoic Suwanee basin sandstone; and (3) whole-rock Sm-Nd and U-Pb zircon evidence for an Archean ([approximately]3.0 Ga) component in the neo-Proterozoic Osceola granitoid(s). Although silicic rocks from throughout Florida have Nd model ages (T[sub DM]) that are predominantly Grenvillian (1.1--1.4 Ga), the absence of a Grenvillian component in zircons separated from granite and sandstone suggests that the model ages represent a mixture of older and younger components. Overall, the evidence for Birimian ([approximately]2.1 Ga) and Liberian ([approximately]3.0 Ga) age components in the Florida basement are consistent with its origin as a rifted block of cratonic Gondwana. In addition to demonstrating a strong affinity between the Florida basement and cratonic West Africa/northern South America, these data provide a basis for comparison with other circum-Atlantic terranes traditionally described as Avalonian/Cadomian, etc.

  9. On the Provenance of Pluto's Nitrogen (N2)

    NASA Astrophysics Data System (ADS)

    Singer, Kelsi N.; Stern, S. Alan

    2015-08-01

    N2 is abundant in Pluto’s atmosphere and on its surface, but the supply is depleted by prodigious atmospheric escape. We demonstrate that cometary impacts could not have delivered enough N mass to resupply Pluto’s N2 atmospheric escape over time; thus Pluto’s N2 is likely endogenous, and therefore was either acquired early in its history or created by chemistry inside/{on} Pluto. We find that cratering could excavate a considerable amount of N2 to resupply the atmosphere against escape if the near-surface N2 reservoir is deep. However, we find that this process likely falls short of that necessary to resupply the atmosphere against escape by at least an order of magnitude. We conclude that either the escape of N2 from Pluto’s atmosphere was on average much lower than the predictions for the current epoch, or that internal activity could be necessary to bring N2 to the surface and resupply escape losses. Observations made by the New Horizons spacecraft in mid-2015 will yield further constraints on the provenance and evolution of Pluto’s surface and atmospheric N2, and could reveal evidence for past or present internal activity.

  10. From Microactions to Macrostructure and Back: A Structurational Approach to the Evolution of Organizational Networks

    ERIC Educational Resources Information Center

    Whitbred, Robert; Fonti, Fabio; Steglich, Christian; Contractor, Noshir

    2011-01-01

    Structuration theory (ST) and network analysis are promising approaches for studying the emergence of communication networks. We offer a model that integrates the conceptual richness of structuration with the precision of relevant concepts and mechanisms offered from communication network research. We leverage methodological advancements (i.e.,…