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Sample records for bottom-up control factors

  1. Bottom-up and top-down controls on picoplankton in the East China Sea

    Directory of Open Access Journals (Sweden)

    C. Guo

    2013-05-01

    Full Text Available Dynamics of picoplankton population distribution in the East China Sea (ECS, a marginal sea in the western North Pacific Ocean, were studied during two "CHOICE-C" cruises in August 2009 (summer and January 2010 (winter. Dilution experiments were conducted during the two cruises to investigate the growth and grazing among picophytoplantkon populations. Picoplankton accounted for an average of ~29% (2% to 88% of community carbon biomass in the ECS on average, with lower percentages in plume region than in shelf and kuroshio regions. Averaged growth rates (μ for Prochlorococcus (Pro, Synechococcus (Syn and picoeukaryotes (peuk were 0.36, 0.89, 0.90 d−1, respectively, in summer, and 0.46, 0.58, 0.56 d−1, respectively, in winter. Seawater salinity and nutrient availability exerted significant controls on picoplankton growth rate. Averaged grazing mortality (m were 0.46, 0.63, 0.68 d−1 in summer, and 0.22, 0.32, 0.22 d−1 in winter for Pro, Syn and peuk respectively. The three populations demonstrated very different distribution patterns regionally and seasonally affected by both bottom-up and top-down controls. In summer, Pro, Syn and peuk were dominant in Kuroshio, transitional and plume regions respectively. Protist grazing consumed 84%, 78%, 73% and 45%, 47%, 57% of production for Pro, Syn and peuk in summer and winter respectively, suggesting more significant top-down controls in summer. In winter, all three populations tended to distribute in offshore regions, although the area of coverage was different (peuk > Syn > Pro. Bottom-up factors can explain as much as 91.5%, 82% and 81.2% of Pro, Syn and peuk abundance variance in winter, while only 59.1% and 43.7% for Pro and peuk in summer. Regionally, Yangtze River discharge plays a significant role in affecting the intensity of top-down control, indicated by significant and negative association between salinity and grazing mortality of all three populations and higher grazing mortality to

  2. Bottom-up control of water hyacinth weevil populations: Do the plants regulate the insects?

    Science.gov (United States)

    A key measure of dietary sufficiency relates to an insect’s reproductive ability so oögenesis, a nutrient-limited process, can be subject to bottom-up regulation. We hypothesized that aquatic nutrient flux seasonally affects ovarian development thereby controlling population growth of two specialis...

  3. DIGESTIF: a universal quality standard for the control of bottom-up proteomics experiments.

    Science.gov (United States)

    Lebert, Dorothée; Louwagie, Mathilde; Goetze, Sandra; Picard, Guillaume; Ossola, Reto; Duquesne, Caroline; Basler, Konrad; Ferro, Myriam; Rinner, Oliver; Aebersold, Ruedi; Garin, Jérôme; Mouz, Nicolas; Brunner, Erich; Brun, Virginie

    2015-02-01

    In bottom-up mass spectrometry-based proteomics analyses, variability at any step of the process, particularly during sample proteolysis, directly affects the sensitivity, accuracy, and precision of peptide detection and quantification. Currently, no generic internal standards are available to control the quality of sample processing steps. This makes it difficult to assess the comparability of MS proteomic data obtained under different experimental conditions. Here, we describe the design, synthesis, and validation of a universal protein standard, called DIGESTIF, that can be added to any biological sample. The DIGESTIF standard consists of a soluble recombinant protein scaffold to which a set of 11 artificial peptides (iRT peptides) with good ionization properties has been incorporated. In the protein scaffold, the amino acids flanking iRT peptide cleavage sites were selected either to favor or hinder protease cleavage. After sample processing, the retention time and relative intensity pattern of the released iRT peptides can be used to assess the quality of sample workup, the extent of digestion, and the performance of the LC-MS system. Thus, DIGESTIF can be used to standardize a broad spectrum of applications, ranging from simple replicate measurements to large-scale biomarker screening in biomedical applications. PMID:25495225

  4. Adaptive genetic variation mediates bottom-up and top-down control in an aquatic ecosystem.

    Science.gov (United States)

    Rudman, Seth M; Rodriguez-Cabal, Mariano A; Stier, Adrian; Sato, Takuya; Heavyside, Julian; El-Sabaawi, Rana W; Crutsinger, Gregory M

    2015-08-01

    Research in eco-evolutionary dynamics and community genetics has demonstrated that variation within a species can have strong impacts on associated communities and ecosystem processes. Yet, these studies have centred around individual focal species and at single trophic levels, ignoring the role of phenotypic variation in multiple taxa within an ecosystem. Given the ubiquitous nature of local adaptation, and thus intraspecific variation, we sought to understand how combinations of intraspecific variation in multiple species within an ecosystem impacts its ecology. Using two species that co-occur and demonstrate adaptation to their natal environments, black cottonwood (Populus trichocarpa) and three-spined stickleback (Gasterosteus aculeatus), we investigated the effects of intraspecific phenotypic variation on both top-down and bottom-up forces using a large-scale aquatic mesocosm experiment. Black cottonwood genotypes exhibit genetic variation in their productivity and consequently their leaf litter subsidies to the aquatic system, which mediates the strength of top-down effects from stickleback on prey abundances. Abundances of four common invertebrate prey species and available phosphorous, the most critically limiting nutrient in freshwater systems, are dictated by the interaction between genetic variation in cottonwood productivity and stickleback morphology. These interactive effects fit with ecological theory on the relationship between productivity and top-down control and are comparable in strength to the effects of predator addition. Our results illustrate that intraspecific variation, which can evolve rapidly, is an under-appreciated driver of community structure and ecosystem function, demonstrating that a multi-trophic perspective is essential to understanding the role of evolution in structuring ecological patterns. PMID:26203004

  5. Cognitive Functions of the Posterior Parietal Cortex: Top-down and bottom-up attentional control

    Directory of Open Access Journals (Sweden)

    Sarah Shomstein

    2012-07-01

    Full Text Available Although much less is known about human parietal cortex than that of homologous monkey cortex, recent studies, employing neuroimaging and neuropsychological methods, have begun to elucidate increasingly fine-grained functional and structural distinctions.\tThis review is focused on recent neuroimaging and neuropsychological studies elucidating the cognitive roles of dorsal and ventral regions of parietal cortex in top-down and bottom-up attentional orienting, and on the interaction between the two attentional allocation mechanisms. Evidence is reviewed arguing that regions along the dorsal areas of the parietal cortex, including the superior parietal lobule (SPL are involved in top-down attentional orienting, while ventral regions including the temporo-parietal junction (TPJ are involved in bottom-up attentional orienting.

  6. Selecting category specific visual information: Top-down and bottom-up control of object based attention.

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    Corradi-Dell'Acqua, Corrado; Fink, Gereon R; Weidner, Ralph

    2015-09-01

    The ability to select, within the complexity of sensory input, the information most relevant for our purposes is influenced by both internal settings (i.e., top-down control) and salient features of external stimuli (i.e., bottom-up control). We here investigated using fMRI the neural underpinning of the interaction of top-down and bottom-up processes, as well as their effects on extrastriate areas processing visual stimuli in a category-selective fashion. We presented photos of bodies or buildings embedded into frequency-matched visual noise to the subjects. Stimulus saliency changed gradually due to an altered degree to which photos stood-out in relation to the surrounding noise (hence generating stronger bottom-up control signals). Top-down settings were manipulated via instruction: participants were asked to attend one stimulus category (i.e., "is there a body?" or "is there a building?"). Highly salient stimuli that were inconsistent with participants' attentional top-down template activated the inferior frontal junction and dorsal parietal regions bilaterally. Stimuli consistent with participants' current attentional set additionally activated insular cortex and the parietal operculum. Furthermore, the extrastriate body area (EBA) exhibited increased neural activity when attention was directed to bodies. However, the latter effect was found only when stimuli were presented at intermediate saliency levels, thus suggesting a top-down modulation of this region only in the presence of weak bottom-up signals. Taken together, our results highlight the role of the inferior frontal junction and posterior parietal regions in integrating bottom-up and top-down attentional control signals. PMID:25735196

  7. Sponge communities on Caribbean coral reefs are structured by factors that are top-down, not bottom-up.

    Directory of Open Access Journals (Sweden)

    Joseph R Pawlik

    Full Text Available Caribbean coral reefs have been transformed in the past few decades with the demise of reef-building corals, and sponges are now the dominant habitat-forming organisms on most reefs. Competing hypotheses propose that sponge communities are controlled primarily by predatory fishes (top-down or by the availability of picoplankton to suspension-feeding sponges (bottom-up. We tested these hypotheses on Conch Reef, off Key Largo, Florida, by placing sponges inside and outside predator-excluding cages at sites with less and more planktonic food availability (15 m vs. 30 m depth. There was no evidence of a bottom-up effect on the growth of any of 5 sponge species, and 2 of 5 species grew more when caged at the shallow site with lower food abundance. There was, however, a strong effect of predation by fishes on sponge species that lacked chemical defenses. Sponges with chemical defenses grew slower than undefended species, demonstrating a resource trade-off between growth and the production of secondary metabolites. Surveys of the benthic community on Conch Reef similarly did not support a bottom-up effect, with higher sponge cover at the shallower depth. We conclude that the structure of sponge communities on Caribbean coral reefs is primarily top-down, and predict that removal of sponge predators by overfishing will shift communities toward faster-growing, undefended species that better compete for space with threatened reef-building corals.

  8. Top-down and bottom-up control of large herbivore populations: a review of natural and human-induced influences

    OpenAIRE

    Gandiwa, E.

    2013-01-01

    The question whether animal populations are top-down and/or bottom-up controlled has motivated a thriving body of research over the past five decades. In this review I address two questions: 1) how do top-down and bottom-up controls influence large herbivore populations? 2) How do human activities and control systems influence the top-down and bottom-up processes that affect large herbivore population dynamics? Previous studies suggest that the relative influence of top-down vs. bottom-up con...

  9. Bottom-up factors influencing riparian willow recovery in Yellowstone National Park

    Science.gov (United States)

    Tercek, M.T.; Stottlemyer, R.; Renkin, R.

    2010-01-01

    After the elimination of wolves (Canis lupis L.) in the 1920s, woody riparian plant communities on the northern range of Yellowstone National Park (YNP) declined an estimated 50%. After the reintroduction of wolves in 19951996, riparian willows (Salix spp.) on YNP's northern range showed significant growth for the first time since the 1920s. However, the pace of willow recovery has not been uniform. Some communities have exceeded 400 cm, while others are still at pre-1995 levels of 250 cm max. height) willow sites where willows had escaped elk (Cervus elaphus L.) browsing with "short" willow sites that could still be browsed. Unlike studies that manipulated willow height with fences and artificial dams, we examined sites that had natural growth differences in height since the reintroduction of wolves. Tall willow sites had greater water availability, more-rapid net soil nitrogen mineralization, greater snow depth, lower soil respiration rates, and cooler summer soil temperatures than nearby short willow sites. Most of these differences were measured both in herbaceous areas adjacent to the willow patches and in the willow patches themselves, suggesting that they were not effects of varying willow height recovery but were instead preexisting site differences that may have contributed to increased plant productivity. Our results agree with earlier studies in experimental plots which suggest that the varying pace of willow recovery has been influenced by abiotic limiting factors that interact with top-down reductions in willow browsing by elk. ?? 2010 Western North American Naturalist.

  10. Optimal Environmental Conditions and Anomalous Ecosystem Responses: Constraining Bottom-up Controls of Phytoplankton Biomass in the California Current System

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    Jacox, Michael G.; Hazen, Elliott L.; Bograd, Steven J.

    2016-06-01

    In Eastern Boundary Current systems, wind-driven upwelling drives nutrient-rich water to the ocean surface, making these regions among the most productive on Earth. Regulation of productivity by changing wind and/or nutrient conditions can dramatically impact ecosystem functioning, though the mechanisms are not well understood beyond broad-scale relationships. Here, we explore bottom-up controls during the California Current System (CCS) upwelling season by quantifying the dependence of phytoplankton biomass (as indicated by satellite chlorophyll estimates) on two key environmental parameters: subsurface nitrate concentration and surface wind stress. In general, moderate winds and high nitrate concentrations yield maximal biomass near shore, while offshore biomass is positively correlated with subsurface nitrate concentration. However, due to nonlinear interactions between the influences of wind and nitrate, bottom-up control of phytoplankton cannot be described by either one alone, nor by a combined metric such as nitrate flux. We quantify optimal environmental conditions for phytoplankton, defined as the wind/nitrate space that maximizes chlorophyll concentration, and present a framework for evaluating ecosystem change relative to environmental drivers. The utility of this framework is demonstrated by (i) elucidating anomalous CCS responses in 1998–1999, 2002, and 2005, and (ii) providing a basis for assessing potential biological impacts of projected climate change.

  11. Spontaneous emission control of single quantum dots in bottom-up nanowire waveguides

    NARCIS (Netherlands)

    Bulgarini, G.; Reimer, M.E.; Zehender, T.; Hocevar, M.; Bakkers, E.P.A.M.; Kouwenhoven, L.P.; Zwiller, V.

    2012-01-01

    Nanowire waveguides with controlled shape are promising for engineering the collection efficiency of quantum light sources. We investigate the exciton lifetime in individual InAsP quantum dots, perfectly positioned on-axis of InP nanowire waveguides. We demonstrate control over the quantum dot spont

  12. Spontaneous emission control of single quantum dots in bottom-up nanowire waveguides

    OpenAIRE

    Bulgarini, Gabriele; Reimer, Michael E.; Zehender, Tilman; Hocevar, Moïra; Bakkers, Erik P. A. M.; Kouwenhoven, Leo P.; Zwiller, Valery

    2012-01-01

    Nanowire waveguides with controlled shape are promising for engineering the collection efficiency of quantum light sources. We investigate the exciton lifetime in individual InAsP quantum dots, perfectly positioned on-axis of InP nanowire waveguides. We demonstrate control over the quantum dot spontaneous emission by varying the nanowire diameter in e-beam patterned arrays, which modifies the coupling efficiency of the emitter to the fundamental waveguide mode. The spontaneous emission rate i...

  13. Temporal shifts in top-down vs. bottom-up control of epiphytic algae in a seagrass ecosystem

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    Whalen, Matthew A.; Duffy, J. Emmett; Grace, James B.

    2013-01-01

    In coastal marine food webs, small invertebrate herbivores (mesograzers) have long been hypothesized to occupy an important position facilitating dominance of habitat-forming macrophytes by grazing competitively superior epiphytic algae. Because of the difficulty of manipulating mesograzers in the field, however, their impacts on community organization have rarely been rigorously documented. Understanding mesograzer impacts has taken on increased urgency in seagrass systems due to declines in seagrasses globally, caused in part by widespread eutrophication favoring seagrass overgrowth by faster-growing algae. Using cage-free field experiments in two seasons (fall and summer), we present experimental confirmation that mesograzer reduction and nutrients can promote blooms of epiphytic algae growing on eelgrass (Zostera marina). In this study, nutrient additions increased epiphytes only in the fall following natural decline of mesograzers. In the summer, experimental mesograzer reduction stimulated a 447% increase in epiphytes, appearing to exacerbate seasonal dieback of eelgrass. Using structural equation modeling, we illuminate the temporal dynamics of complex interactions between macrophytes, mesograzers, and epiphytes in the summer experiment. An unexpected result emerged from investigating the interaction network: drift macroalgae indirectly reduced epiphytes by providing structure for mesograzers, suggesting that the net effect of macroalgae on seagrass depends on macroalgal density. Our results show that mesograzers can control proliferation of epiphytic algae, that top-down and bottom-up forcing are temporally variable, and that the presence of macroalgae can strengthen top-down control of epiphytic algae, potentially contributing to eelgrass persistence.

  14. Relative Influence of Top-Down ond Bottom-Up Controls on Mixed Severity Burn Patterns in Yosemite National Park, California, USA

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    Kane, V. R.; Povak, N.; Brooks, M.; Collins, B.; Smith, D.; Churchill, D.

    2015-12-01

    with increased fire severity. The level of control among these factors varies across fire sizes indicating possible scale-wise shifts in dominance among controls. We will discuss differences in drivers across fire sizes to help identify where local climate conditions supersede bottom-up controls.

  15. The benefits of China's efforts on gaseous pollutant control indicated by the bottom-up emissions and satellite observation

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    Xia, Y.; Zhao, Y.

    2015-12-01

    To evaluate the effectiveness of national policies of air pollution control, the emissions of SO2, NOX, CO and CO2 in China are estimated with a bottom-up method from 2000 to 2014, and vertical column densities (VCD) from satellite observation are used to evaluate the inter-annual trends and spatial distribution of emissions and the temporal and spatial patterns of ambient levels of gaseous pollutants across the country. In particular, an additional emission case named STD case, which combines the most recent issued emission standards for specific industrial sources, is developed for 2012-2014. The inter-annual trends in emissions and VCDs match well except for SO2, and the revised emissions in STD case improve the comparison, implying the benefits of emission control for most recent years. Satellite retrieval error, underestimation of emission reduction and improved atmospheric oxidization caused the differences between emissions and VCDs trend of SO2. Coal-fired power plants play key roles in SO2 and NOX emission reduction. As suggested by VCD and emission inventory, the control of CO in 11th five year plan (FYP) period was more effective than that in the 12th FYP period, while the SO2 appeared opposite. As the new control target added in 12th FYP, NOX emissions have been clearly decreased 4.3 Mt from 2011 to 2014, in contrast to the fast growth before 2011. The inter-annual trends in NO2 VCDs has the poorest correlation with vehicle ownership (R=0.796), due to the staged emission standard of vehicles. In developed regions, transportation has become the main pollutants emission source and we prove this by comparing VCDs of NO2 to VCDs of SO2. Moreover, air quality in mega cities has been evaluated based on satellite observation and emissions, and results indicate that Beijing suffered heavily from the emissions from Hebei and Tianjin, while the local emissions tend to dominate in Shanghai.

  16. A statistical mixture method to reveal bottom-up and top-down factors guiding the eye-movements

    OpenAIRE

    Couronné, Thomas; Guérin-Dugué, Anne; Michel DUBOIS; Faye, Pauline; MARENDAZ, Christian

    2010-01-01

    When people gaze at real scenes, their visual attention is driven both by a set of bottom-up processes coming from the signal properties of the scene and also from top-down effects such as the task, the affective state, prior knowledge, or the semantic context. The context of this study is an assessment of manufactured objects (here car cab interior). From this dedicated context, this work describes a set of methods to analyze the eye-movements during the visual scene evaluation. But these me...

  17. Toward improved prediction of the bedrock depth underneath hillslopes: Bayesian inference of the bottom-up control hypothesis using high-resolution topographic data

    Science.gov (United States)

    Gomes, Guilherme J. C.; Vrugt, Jasper A.; Vargas, Eurípedes A.

    2016-04-01

    The depth to bedrock controls a myriad of processes by influencing subsurface flow paths, erosion rates, soil moisture, and water uptake by plant roots. As hillslope interiors are very difficult and costly to illuminate and access, the topography of the bedrock surface is largely unknown. This essay is concerned with the prediction of spatial patterns in the depth to bedrock (DTB) using high-resolution topographic data, numerical modeling, and Bayesian analysis. Our DTB model builds on the bottom-up control on fresh-bedrock topography hypothesis of Rempe and Dietrich (2014) and includes a mass movement and bedrock-valley morphology term to extent the usefulness and general applicability of the model. We reconcile the DTB model with field observations using Bayesian analysis with the DREAM algorithm. We investigate explicitly the benefits of using spatially distributed parameter values to account implicitly, and in a relatively simple way, for rock mass heterogeneities that are very difficult, if not impossible, to characterize adequately in the field. We illustrate our method using an artificial data set of bedrock depth observations and then evaluate our DTB model with real-world data collected at the Papagaio river basin in Rio de Janeiro, Brazil. Our results demonstrate that the DTB model predicts accurately the observed bedrock depth data. The posterior mean DTB simulation is shown to be in good agreement with the measured data. The posterior prediction uncertainty of the DTB model can be propagated forward through hydromechanical models to derive probabilistic estimates of factors of safety.

  18. Bottom-up versus top-down control of tree regeneration in the Bialowieza Primeval Forest, Poland

    NARCIS (Netherlands)

    Kuijper, D.P.J.; Cromsigt, J.P.G.M.; Jedrzejewska, B.A.; Miscicki, S.C.; Jedrzejewski, W.A.; Kweczlich, I.C.

    2010-01-01

    We tested the interactions between biotic and abiotic factors in structuring temperate forest communities by comparing tree recruitment after 7 years inside 30 pairs of exclosure (excluding ungulates: red deer, roe deer, bison, moose, wild boar) and control plots (7 × 7 m each) in one of the most na

  19. Top-down, bottom-up and physical controls on diatom-diazotroph assemblage growth in the Amazon River plume

    OpenAIRE

    M. R. Stukel; V. J. Coles; Brooks, M. T.; Hood, R.R.

    2014-01-01

    The nutrient-rich waters of the Amazon River plume (ARP) support dense blooms of diatom-diazotroph assemblages (DDAs) that introduce large quantities of new nitrogen to the planktonic ecosystem and, unlike other nitrogen-fixers, are likely to directly fuel vertical carbon flux. To investigate the factors controlling DDA blooms, we develop a five phytoplankton (cyanobacteria, diatoms, unicellular microbial diazotrophs, DDAs, and Trichodesmium), two zooplankton model and embed...

  20. Top-down, bottom-up and physical controls on diatom-diazotroph assemblage growth in the Amazon River Plume

    OpenAIRE

    M. R. Stukel; V. J. Coles; Brooks, M. T.; Hood, R.R.

    2013-01-01

    The nutrient-rich waters of the Amazon River Plume (ARP) support dense blooms of diatom-diazotroph assemblages (DDA) that introduce large quantities of new nitrogen to the planktonic ecosystem and, unlike other nitrogen-fixers, are likely to directly fuel vertical carbon flux. To investigate the factors controlling DDA blooms, we develop a five phytoplankton (cyanobacteria, diatoms, unicellular microbial diazotrophs, DDA, and Trichodesmium), two zooplankton model and embed it within a 1/6° re...

  1. Top-down and bottom-up factors affecting seabird population trends in the California current system (1985-2006)

    Science.gov (United States)

    Ainley, David G.; David Hyrenbach, K.

    2010-03-01

    To characterize the environmental factors affecting seabird population trends in the central portion of the California current system (CCS), we analyzed standardized vessel-based surveys collected during the late spring (May-June) upwelling season over 22 yr (1985-2006). We tested the working hypothesis that population trends are related to species-specific foraging ecology, and predicted that temporal variation in population size should be most extreme in diving species with higher energy expenditure during foraging. We related variation in individual species abundance (number km -2) to seasonally lagged (late winter, early spring, late spring) and concurrent ocean conditions, and to long-term trends (using a proxy variable: year) during a multi-decadal period of major fluctuations in the El Niño-Southern oscillation (ENSO) and the Pacific decadal oscillation (PDO). We considered both remote (Multivariate ENSO Index, PDO) and local (coastal upwelling indices and sea-surface temperature) environmental variables as proxies for ocean productivity and prey availability. We also related seabird trends to those of potentially major trophic competitors, humpback ( Megaptera novaeangliae) and blue ( Balaenoptera musculus) whales, which increased in number 4-5-fold midway during our study. Cyclical oscillations in seabird abundance were apparent in the black-footed albatross ( Phoebastria nigripes), and decreasing trends were documented for ashy storm-petrel ( Oceanodroma homochroa), pigeon guillemot ( Cepphus columbus), rhinoceros auklet ( Cerorhinca monocerata), Cassin’s auklet ( Ptychoramphus aleuticus), and western gull ( Larus occidentalis); the sooty shearwater ( Puffinus griseus), exhibited a marked decline before signs of recovery at the end of the study period. The abundance of nine other focal species varied with ocean conditions, but without decadal or long-term trends. Six of these species have the largest global populations in the CCS, and four are highly

  2. Top-down, bottom-up and physical controls on diatom-diazotroph assemblage growth in the Amazon River Plume

    Directory of Open Access Journals (Sweden)

    M. R. Stukel

    2013-08-01

    Full Text Available The nutrient-rich waters of the Amazon River Plume (ARP support dense blooms of diatom-diazotroph assemblages (DDA that introduce large quantities of new nitrogen to the planktonic ecosystem and, unlike other nitrogen-fixers, are likely to directly fuel vertical carbon flux. To investigate the factors controlling DDA blooms, we develop a five phytoplankton (cyanobacteria, diatoms, unicellular microbial diazotrophs, DDA, and Trichodesmium, two zooplankton model and embed it within a 1/6° resolution physical model of the tropical and subtropical Atlantic. The model generates realistic DDA blooms in the ARP and also exhibits basin-wide primary production, nitrogen fixation, and grazing rates consistent with observed values. By following ARP water parcels with synthetic Lagrangian drifters released at the river mouth we are able to assess the relative impacts of grazing, nutrient supply, and physical forcing on DDA bloom formation. DDA bloom formation is stimulated in the silica-rich water of the ARP by decreases in grazing pressure when mesozooplankton (which co-occur in high densities with coastal diatom blooms concentrations decrease. Bloom termination is driven primarily by silica limitation of the DDA. In agreement with in situ data, this net growth niche for DDA exists in a salinity range from ~ 20–34 PSU, although this co-occurrence is coincidental rather than causative. Because net growth rates are relatively modest, bloom formation in ARP water parcels depends critically on the time spent in this ideal habitat, with high DDA biomass only occurring when water parcels spent > 23 days in the optimal habitat niche.

  3. Top-down, bottom-up and physical controls on diatom-diazotroph assemblage growth in the Amazon River plume

    Science.gov (United States)

    Stukel, M. R.; Coles, V. J.; Brooks, M. T.; Hood, R. R.

    2014-06-01

    The nutrient-rich waters of the Amazon River plume (ARP) support dense blooms of diatom-diazotroph assemblages (DDAs) that introduce large quantities of new nitrogen to the planktonic ecosystem and, unlike other nitrogen-fixers, are likely to directly fuel vertical carbon flux. To investigate the factors controlling DDA blooms, we develop a five phytoplankton (cyanobacteria, diatoms, unicellular microbial diazotrophs, DDAs, and Trichodesmium), two zooplankton model and embed it within a 1/6° resolution physical model of the tropical and subtropical Atlantic. The model generates realistic DDA blooms in the ARP and also exhibits basin-wide primary production, nitrogen fixation, and grazing rates consistent with observed values. By following ARP water parcels with synthetic Lagrangian drifters released at the river mouth we are able to assess the relative impacts of grazing, nutrient supply, and physical forcing on DDA bloom formation. DDA bloom formation is stimulated in the nitrogen-poor and silica-rich water of the ARP by decreases in grazing pressure when mesozooplankton (which co-occur in high densities with coastal diatom blooms) concentrations decrease. Bloom termination is driven primarily by silica limitation of the DDAs. In agreement with in situ data, this net growth niche for DDAs exists in a salinity range from ∼20-34 PSU, although this co-occurrence is coincidental rather than causative. Because net growth rates are relatively modest, bloom formation in ARP water parcels depends critically on the time spent in this ideal habitat, with high DDA biomass only occurring when water parcels spent >23 days in the optimal habitat niche.

  4. Culture from the Bottom Up

    Science.gov (United States)

    Atkinson, Dwight; Sohn, Jija

    2013-01-01

    The culture concept has been severely criticized for its top-down nature in TESOL, leading arguably to its falling out of favor in the field. But what of the fact that people do "live culturally" (Ingold, 1994)? This article describes a case study of culture from the bottom up--culture as understood and enacted by its individual users.…

  5. The influence of top-down, bottom-up and abiotic factors on the moose (Alces alces) population of Isle Royale.

    OpenAIRE

    Vucetich, John A.; Rolf O Peterson

    2004-01-01

    Long-term, concurrent measurement of population dynamics and associated top-down and bottom-up processes are rare for unmanipulated, terrestrial systems. Here, we analyse populations of moose, their predators (wolves, Canis lupus), their primary winter forage (balsam fir, Abies balsamea) and several climatic variables that were monitored for 40 consecutive years in Isle Royale National Park (544 km2), Lake Superior, USA. We judged the relative importance of top-down, bottom-up and abiotic fac...

  6. The control of automatic imitation based on bottom-up and top-down cues to animacy: insights from brain and behavior.

    Science.gov (United States)

    Klapper, André; Ramsey, Richard; Wigboldus, Daniël; Cross, Emily S

    2014-11-01

    Humans automatically imitate other people's actions during social interactions, building rapport and social closeness in the process. Although the behavioral consequences and neural correlates of imitation have been studied extensively, little is known about the neural mechanisms that control imitative tendencies. For example, the degree to which an agent is perceived as human-like influences automatic imitation, but it is not known how perception of animacy influences brain circuits that control imitation. In the current fMRI study, we examined how the perception and belief of animacy influence the control of automatic imitation. Using an imitation-inhibition paradigm that involves suppressing the tendency to imitate an observed action, we manipulated both bottom-up (visual input) and top-down (belief) cues to animacy. Results show divergent patterns of behavioral and neural responses. Behavioral analyses show that automatic imitation is equivalent when one or both cues to animacy are present but reduces when both are absent. By contrast, right TPJ showed sensitivity to the presence of both animacy cues. Thus, we demonstrate that right TPJ is biologically tuned to control imitative tendencies when the observed agent both looks like and is believed to be human. The results suggest that right TPJ may be involved in a specialized capacity to control automatic imitation of human agents, rather than a universal process of conflict management, which would be more consistent with generalist theories of imitative control. Evidence for specialized neural circuitry that "controls" imitation offers new insight into developmental disorders that involve atypical processing of social information, such as autism spectrum disorders. PMID:24742157

  7. Fabricación de electrodos para control de transporte y alineamiento a micro y nanoescalas usando técnicas bottom-up y top-down

    Directory of Open Access Journals (Sweden)

    Darwin Rodríguez

    2014-12-01

    Full Text Available El continuo avance de aplicaciones en dispositivos de autoensamble, posicionamiento, sensores, actuadores, y que permitan controladamente la manipulación de micro y nanoestructuras, han generado amplio interés en el desarrollo de metodologías que permitan optimizar la fabricación de dispositivos para el control y manipulación a micro y nanoescalas. Este proyecto explora técnicas de fabricación de electrodos con el fin de encontrar una técnica óptima y reproducible. Se compara el rendimiento de cada técnica y se describen protocolos de limpieza y seguridad. Se diseñan e implementan tres geometrías para movilizar y posicionar micro y nanopartículas de hierro en una solución de aceite natural. Finalmente se generan campos eléctricos a partir de electroforesis, con el fin de encontrar la curva que describe el desplazamiento de las partículas con respecto al potencial aplicado. Estos resultados generan gran impacto en los actuales esfuerzos de fabricación bottom-up (controlando con campos la ubicación y la movilidad en dispositivos electrónicos. El hecho de fabricar geometría planar con electrodos genera la posibilidad de que se pueda integrar movimiento de partículas a los circuitos integrados que se fabrican en la actualidad.

  8. Benefits of China's efforts in gaseous pollutant control indicated by the bottom-up emissions and satellite observations 2000-2014

    Science.gov (United States)

    Xia, Yinmin; Zhao, Yu; Nielsen, Chris P.

    2016-07-01

    To evaluate the effectiveness of national air pollution control policies, the emissions of SO2, NOX, CO and CO2 in China are estimated using bottom-up methods for the most recent 15-year period (2000-2014). Vertical column densities (VCDs) from satellite observations are used to test the temporal and spatial patterns of emissions and to explore the ambient levels of gaseous pollutants across the country. The inter-annual trends in emissions and VCDs match well except for SO2. Such comparison is improved with an optimistic assumption in emission estimation that the emission standards for given industrial sources issued after 2010 have been fully enforced. Underestimation of emission abatement and enhanced atmospheric oxidization likely contribute to the discrepancy between SO2 emissions and VCDs. As suggested by VCDs and emissions estimated under the assumption of full implementation of emission standards, the control of SO2 in the 12th Five-Year Plan period (12th FYP, 2011-2015) is estimated to be more effective than that in the 11th FYP period (2006-2010), attributed to improved use of flue gas desulfurization in the power sector and implementation of new emission standards in key industrial sources. The opposite was true for CO, as energy efficiency improved more significantly from 2005 to 2010 due to closures of small industrial plants. Iron & steel production is estimated to have had particularly strong influence on temporal and spatial patterns of CO. In contrast to fast growth before 2011 driven by increased coal consumption and limited controls, NOX emissions decreased from 2011 to 2014 due to the penetration of selective catalytic/non-catalytic reduction systems in the power sector. This led to reduced NO2 VCDs, particularly in relatively highly polluted areas such as the eastern China and Pearl River Delta regions. In developed areas, transportation is playing an increasingly important role in air pollution, as suggested by the increased ratio of NO2 to SO

  9. Bottom-up Initiatives for Photovoltaic: Incentives and Barriers

    Directory of Open Access Journals (Sweden)

    Kathrin Reinsberger

    2014-06-01

    Full Text Available When facing the challenge of restructuring the energy system, bottom-up initiatives can aid the diffusion of decentralized and clean energy technologies. We focused here on a bottom-up initiative of citizen-funded and citizen-operated photovoltaic power plants. The project follows a case study-based approach and examines two different community initiatives. The aim is to investigate the potential incentives and barriers relating to participation or non-participation in predefined community PV projects. Qualitative, as well as quantitative empirical research was used to examine the key factors in the further development of bottom-up initiatives as contributors to a general energy transition.

  10. Implementation Alternatives for Bottom-Up Evaluation

    OpenAIRE

    Brass, Stefan

    2010-01-01

    Bottom-up evaluation is a central part of query evaluation / program execution in deductive databases. It is used after a source code optimization like magic sets or SLDmagic that ensures that only facts relevant for the query can be derived. Then bottom-up evaluation simply performs the iteration of the standard TP -operator to compute the minimal model. However, there are different ways to implement bottom-up evaluation efficiently. Since this is most critical for the performance of a deduc...

  11. Bottom-up approach to silicon nanoelectronics

    OpenAIRE

    Mizumita, Hiroshi; Oda, S

    2005-01-01

    Submitted on behalf of EDA Publishing Association (http://irevues.inist.fr/handle/2042/5920) International audience This paper presents a brief review of our recent work investigating a novel bottom-up approach to realize silicon based nanoelectronics. We discuss fabrication technique, electronic properties and device applications of silicon nanodots as a building block for nanoscale silicon devices.

  12. The control of automatic imitation based on bottom-up and top-down cues to animacy: Insights from brain and behavior

    NARCIS (Netherlands)

    Klapper, A.P.; Ramsey, R.; Wigboldus, D.H.J.; Cross, E.S.

    2014-01-01

    Humans automatically imitate other people's actions during social interactions, building rapport and social closeness in the process. Although the behavioral consequences and neural correlates of imitation have been studied extensively, little is known about the neural mechanisms that control imitat

  13. Bottom-up organic integrated circuits

    OpenAIRE

    Smits, Edsger C. P; Mathijssen, Simon G. J.; van Hal, Paul A.; Setayesh, Sepas; Geuns, Thomas C. T.; Mutsaers, Kees A. H. A.; Cantatore, Eugenio; Wondergem, Harry J.; Werzer, Oliver; Resel, Roland; Kemerink, Martijn; Kirchmeyer, Stephan; Muzafarov, Aziz M.; Ponomarenko, Sergei A.; de Boer, Bert

    2008-01-01

    Self- assembly - the autonomous organization of components into patterns and structures(1) - is a promising technology for the mass production of organic electronics. Making integrated circuits using a bottom- up approach involving self- assembling molecules was proposed(2) in the 1970s. The basic building block of such an integrated circuit is the self- assembled- monolayer field- effect transistor ( SAMFET), where the semiconductor is a monolayer spontaneously formed on the gate dielectric....

  14. Bottom-Up versus Top-Down Control of Hypo- and Epilimnion Free-Living Bacterial Community Structures in Two Neighboring Freshwater Lakes▿†‡

    OpenAIRE

    Berdjeb, Lyria; Ghiglione, Jean-François; Jacquet, Stéphan

    2011-01-01

    Bacterioplankton plays a central role in the microbial functioning of lacustrine ecosystems; however, factors that constrain its structural variation are still poorly understood. Here we evaluated the driving forces exerted by a large set of environmental and biological parameters on the temporal and spatial dynamics of free-living bacterial community structures (BCS) in two neighboring perialpine lakes, Lake Bourget and Lake Annecy, which differ in trophic status. We analyzed monthly data fr...

  15. The control of automatic imitation based on bottom-up and top-down cues to animacy: Insights from brain and behavior

    OpenAIRE

    Klapper, A.P.; Ramsey, R; Wigboldus, D.H.J.; E. S. Cross

    2014-01-01

    Humans automatically imitate other people's actions during social interactions, building rapport and social closeness in the process. Although the behavioral consequences and neural correlates of imitation have been studied extensively, little is known about the neural mechanisms that control imitative tendencies. For example, the degree to which an agent is perceived as human-like influences automatic imitation, but it is not known how perception of animacy influences brain circuits that con...

  16. Bottom-up holographic approach to QCD

    Energy Technology Data Exchange (ETDEWEB)

    Afonin, S. S. [V. A. Fock Department of Theoretical Physics, Saint Petersburg State University, 1 ul. Ulyanovskaya, 198504 (Russian Federation)

    2016-01-22

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as “holographic QCD” or “AdS/QCD approach”. One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model.

  17. Bottom-up holographic approach to QCD

    International Nuclear Information System (INIS)

    One of the most known result of the string theory consists in the idea that some strongly coupled gauge theories may have a dual description in terms of a higher dimensional weakly coupled gravitational theory — the so-called AdS/CFT correspondence or gauge/gravity correspondence. The attempts to apply this idea to the real QCD are often referred to as “holographic QCD” or “AdS/QCD approach”. One of directions in this field is to start from the real QCD and guess a tentative dual higher dimensional weakly coupled field model following the principles of gauge/gravity correspondence. The ensuing phenomenology can be then developed and compared with experimental data and with various theoretical results. Such a bottom-up holographic approach turned out to be unexpectedly successful in many cases. In the given short review, the technical aspects of the bottom-up holographic approach to QCD are explained placing the main emphasis on the soft wall model

  18. Bottom-up assembly of metallic germanium

    Science.gov (United States)

    Scappucci, Giordano; Klesse, Wolfgang M.; Yeoh, Lareine A.; Carter, Damien J.; Warschkow, Oliver; Marks, Nigel A.; Jaeger, David L.; Capellini, Giovanni; Simmons, Michelle Y.; Hamilton, Alexander R.

    2015-08-01

    Extending chip performance beyond current limits of miniaturisation requires new materials and functionalities that integrate well with the silicon platform. Germanium fits these requirements and has been proposed as a high-mobility channel material, a light emitting medium in silicon-integrated lasers, and a plasmonic conductor for bio-sensing. Common to these diverse applications is the need for homogeneous, high electron densities in three-dimensions (3D). Here we use a bottom-up approach to demonstrate the 3D assembly of atomically sharp doping profiles in germanium by a repeated stacking of two-dimensional (2D) high-density phosphorus layers. This produces high-density (1019 to 1020 cm-3) low-resistivity (10-4Ω · cm) metallic germanium of precisely defined thickness, beyond the capabilities of diffusion-based doping technologies. We demonstrate that free electrons from distinct 2D dopant layers coalesce into a homogeneous 3D conductor using anisotropic quantum interference measurements, atom probe tomography, and density functional theory.

  19. Wikipedia: organisation from a bottom-up approach

    OpenAIRE

    Spek, Sander; Postma, Eric; Herik, H. Jaap van den

    2006-01-01

    Wikipedia can be considered as an extreme form of a self-managing team, as a means of labour division. One could expect that this bottom-up approach, with the absense of top-down organisational control, would lead to a chaos, but our analysis shows that this is not the case. In the Dutch Wikipedia, an integrated and coherent data structure is created, while at the same time users succeed in distributing roles by self-selection. Some users focus on an area of expertise, while others edit over ...

  20. Bottom-up Attention Orienting in Young Children with Autism

    Science.gov (United States)

    Amso, Dima; Haas, Sara; Tenenbaum, Elena; Markant, Julie; Sheinkopf, Stephen J.

    2014-01-01

    We examined the impact of simultaneous bottom-up visual influences and meaningful social stimuli on attention orienting in young children with autism spectrum disorders (ASDs). Relative to typically-developing age and sex matched participants, children with ASDs were more influenced by bottom-up visual scene information regardless of whether…

  1. Nanoelectronics: Thermoelectric Phenomena in «Bottom-Up» Approach

    OpenAIRE

    Yu.A. Kruglyak; P.A. Kondratenko; Yu.М. Lopatkin

    2014-01-01

    Thermoelectric phenomena of Seebeck and Peltier, quality indicators and thermoelectric optimization, ballistic and diffusive phonon heat current are discussed in the frame of the «bottom-up» approach of modern nanoelectronics.

  2. Nanoelectronics: Thermoelectric Phenomena in «Bottom-Up» Approach

    Directory of Open Access Journals (Sweden)

    Yu.A. Kruglyak

    2014-04-01

    Full Text Available Thermoelectric phenomena of Seebeck and Peltier, quality indicators and thermoelectric optimization, ballistic and diffusive phonon heat current are discussed in the frame of the «bottom-up» approach of modern nanoelectronics.

  3. Learning affects top down and bottom up modulation of eye movements in decision making

    DEFF Research Database (Denmark)

    Orquin, Jacob Lund; Bagger, Martin; Mueller Loose, Simone

    2013-01-01

    different information presentation formats. We thereby operationalized top down and bottom up control as the effect of individual utility levels and presentation formats on attention capture on a trial-by-trial basis. The experiment revealed an increase in top down control of eye movements over time...

  4. Learning affects top down and bottom up modulation of eye movements in decision making

    Directory of Open Access Journals (Sweden)

    Jacob L. Orquin

    2013-11-01

    Full Text Available Repeated decision making is subject to changes over time such as decreases in decision time and information use and increases in decision accuracy. We show that a traditional strategy selection view of decision making cannot account for these temporal dynamics without relaxing main assumptions about what defines a decision strategy. As an alternative view we suggest that temporal dynamics in decision making are driven by attentional and perceptual processes and that this view has been expressed in the information reduction hypothesis. We test the information reduction hypothesis by integrating it in a broader framework of top down and bottom up processes and derive the predictions that repeated decisions increase top down control of attention capture which in turn leads to a reduction in bottom up attention capture. To test our hypotheses we conducted a repeated discrete choice experiment with three different information presentation formats. We thereby operationalized top down and bottom up control as the effect of individual utility levels and presentation formats on attention capture on a trial-by-trial basis. The experiment revealed an increase in top down control of eye movements over time and that decision makers learn to attend to high utility stimuli and ignore low utility stimuli. We furthermore find that the influence of presentation format on attention capture reduces over time indicating diminishing bottom up control.

  5. Two Dimensional Polymerization of Graphene Oxide: Bottom-up Approach

    OpenAIRE

    Atanasov, Victor; Russev, Stoyan; Lyutov, Lyudmil; Zagranyarski, Yulian; Dimitrova, Iglika; Avdeev, Georgy; Avramova, Ivalina; Vulcheva, Evgenia; Kirilov, Kiril; Tzonev, Atanas; Abrashev, Miroslav; Tsutsumanova, Gichka

    2012-01-01

    We demonstrate a bottom-up synthesis of structures similar to graphene oxide via a two dimensional polymerization. Experimental evidence and discussion are conveyed as well as a general framework for this two dimensional polymerization. The proposed morphologies and lattice structures of these graphene oxides are derived from aldol condensation of alternating three nucleophilic and three electrophilic centers of benzenetriol.

  6. Bottom-up effects on attention capture and choice

    DEFF Research Database (Denmark)

    Peschel, Anne; Orquin, Jacob Lund; Mueller Loose, Simone

    information available to form a decision. Does changing one visual cue in the stimulus set affect attention towards this cue and what does that mean for the choice outcome? To address this, we conducted a combined eye tracking and choice experiment in a consumer choice setting with visual shelf simulations of......Attention processes and decision making are accepted to be closely linked together because only information that is attended to can be incorporated in the decision process. Little is known however, to which extent bottom-up processes of attention affect stimulus selection and therefore the...... different product categories. Surface size and visual saliency of a product label were manipulated to determine bottom-up effects on attention and choice. Results show a strong and significant increase in attention in terms of fixation likelihood towards product labels which are larger and more visually...

  7. Bottom-up approaches for defining future climate mitigation commitments

    Energy Technology Data Exchange (ETDEWEB)

    Den Elzen, M.G.J.; Berk, M.M.

    2004-07-01

    This report analyses a number of alternative, bottom-up approaches, i.e. technology and performance standards; technology Research and Development agreements, sectoral targets (national /transnational), sector based Clean Development Mechanism (CDM), and sustainable development policies and measures (SD-PAMs). Included are technology and performance standards; technology, research and development agreements, sectoral targets (national /transnational), and sector-based (CDM), and sustainable development policies and measures (SD-PAMs). A more bottom-up approach for defining national emission targets, the so-called Triptych approach is also explored and compared with more top-down types of approaches (Multi-Stage and Contraction and Convergence) based on a quantitative and qualitative analysis. While bottom-up approaches are concluded as being valuable components of a future climate regime, they, in themselves, do not seem to offer a real alternative to emission reduction and limitation targets, as they provide little certainty about the overall environmental effectiveness of climate policies. In comparison with Multi-stage and the C and C approaches, the global Triptych approach offers the opportunity of early participation by developing countries' without the risk of creating large amounts of surplus emissions as in C and C; in using the approach we also avoid the need for dividing up the non-Annex I countries as in Multi-Stage. However, there will be substantial implementation problems related to the institutional and technical capabilities required. Thus it would seem better to exclude the least developing countries and have them first participate in some of the alternative bottom-up approaches.

  8. Magic for Filter Optimization in Dynamic Bottom-up Processing

    CERN Document Server

    Minnen, G

    1996-01-01

    Off-line compilation of logic grammars using Magic allows an incorporation of filtering into the logic underlying the grammar. The explicit definite clause characterization of filtering resulting from Magic compilation allows processor independent and logically clean optimizations of dynamic bottom-up processing with respect to goal-directedness. Two filter optimizations based on the program transformation technique of Unfolding are discussed which are of practical and theoretical interest.

  9. Bottom-up Budgeting FY 2015 Assessment: Camarines Sur

    OpenAIRE

    Maramot, Joyce Anne; Yasay, Donald B.; de Guzman, Reinier

    2015-01-01

    Bottom-up budgeting (BUB) is an adaptation of the participatory budgeting model in identifying and providing solutions to poverty at the municipal/city level. Leaders of civil society organizations engage with LGU officials in formulating a poverty alleviation plan to be considered in preparing the budget of national agencies the following fiscal year. This paper reports on how the guideline was implemented in three municipalities in Camarines Sur. The study then presents suggestions and reco...

  10. Bottom-up or top-down in dream neuroscience? A top-down critique of two bottom-up studies.

    Science.gov (United States)

    Foulkes, David; Domhoff, G William

    2014-07-01

    Recent neuroscientific studies of dreaming, specifically those in relation to waking sensory-motor impairments, but also more generally, betray a faulty understanding of the sort of process that dreaming is. They adhere to the belief that dreaming is a bottom-up phenomenon, whose form and content is dictated by sensory-motor brain stem activity, rather than a top-down process initiated and controlled by higher-level cognitive systems. But empirical data strongly support the latter alternative, and refute the conceptualization and interpretation of recent studies of dreaming in sensory-motor impairment in particular and of recent dream neuroscience in general. PMID:24905546

  11. A Bottom-Up Approach to SUSY Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Claus; /SLAC

    2011-11-11

    This paper proposes a new way to do event generation and analysis in searches for new physics at the LHC. An abstract notation is used to describe the new particles on a level which better corresponds to detector resolution of LHC experiments. In this way the SUSY discovery space can be decomposed into a small number of eigenmodes each with only a few parameters, which allows to investigate the SUSY parameter space in a model-independent way. By focusing on the experimental observables for each process investigated the Bottom-Up Approach allows to systematically study the boarders of the experimental efficiencies and thus to extend the sensitivity for new physics.

  12. Recent progress in backreacted bottom-up holographic QCD

    Energy Technology Data Exchange (ETDEWEB)

    Järvinen, Matti [Laboratoire de Physique Théorique, École Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05 (France)

    2016-01-22

    Recent progress in constructing holographic models for QCD is discussed, concentrating on the bottom-up models which implement holographically the renormalization group flow of QCD. The dynamics of gluons can be modeled by using a string-inspired model termed improved holographic QCD, and flavor can be added by introducing space filling branes in this model. The flavor fully backreacts to the glue in the Veneziano limit, giving rise to a class of models which are called V-QCD. The phase diagrams and spectra of V-QCD are in good agreement with results for QCD obtained by other methods.

  13. The Interplay of Top-Down and Bottom-Up

    DEFF Research Database (Denmark)

    Winkler, Till; Brown, Carol V.; Ozturk, Pinar

    2014-01-01

    The exchange of patient health information across different organizations involved in healthcare delivery has potential benefits for a wide range of stakeholders. However, many governments in Europe and in the U.S. have, despite both top-down and bottom-up initiatives, experienced major barriers in...... achieving sustainable models for implementing health information exchange (HIE) throughout their healthcare systems. In the case of the U.S., three years after stimulus funding allocated as part of the 2009 HITECH Act, the extent to which government funding will be needed to sustain health information...

  14. Distinguishing Top-Down From Bottom-Up Effects

    OpenAIRE

    Shea, Nicholas

    2015-01-01

    The distinction between top-down and bottom-up effects is widely relied on in experimental psychology. However, there is an important problem with the way it is normally defined. Top-down effects are effects of previously-stored information on processing the current input. But on the face of it that includes the information that is implicit in the operation of any psychological process – in its dispositions to transition from some types of representational state to others. This paper suggests...

  15. Bottom-up graphene nanoribbon field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Patrick B. [Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Pedramrazi, Zahra [Department of Physics, University of California, Berkeley, California 94720 (United States); Madani, Ali [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Chen, Yen-Chia; Crommie, Michael F. [Department of Physics, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States); Oteyza, Dimas G. de [Department of Physics, University of California, Berkeley, California 94720 (United States); Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, San Sebastián E-20018 (Spain); Chen, Chen [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Fischer, Felix R. [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States); Bokor, Jeffrey, E-mail: jbokor@eecs.berkeley.edu [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, California 94720 (United States)

    2013-12-16

    Recently developed processes have enabled bottom-up chemical synthesis of graphene nanoribbons (GNRs) with precise atomic structure. These GNRs are ideal candidates for electronic devices because of their uniformity, extremely narrow width below 1 nm, atomically perfect edge structure, and desirable electronic properties. Here, we demonstrate nano-scale chemically synthesized GNR field-effect transistors, made possible by development of a reliable layer transfer process. We observe strong environmental sensitivity and unique transport behavior characteristic of sub-1 nm width GNRs.

  16. Top-down and bottom-up definitions of human failure events in human reliability analysis

    International Nuclear Information System (INIS)

    In the probabilistic risk assessments (PRAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question is crucial, however, as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PRAs tend to be top-down - defined as a subset of the PRA - whereas the HFEs used in petroleum quantitative risk assessments (QRAs) often tend to be bottom-up - derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.

  17. Inverse Magnetic Catalysis in Bottom-Up Holographic QCD

    CERN Document Server

    Evans, Nick; Scott, Marc

    2016-01-01

    We explore the effect of magnetic field on chiral condensation in QCD via a simple bottom up holographic model which inputs QCD dynamics through the running of the anomalous dimension of the quark bilinear. Bottom up holography is a form of effective field theory and we use it to explore the dependence on the coefficients of the two lowest order terms linking the magnetic field and the quark condensate. In the massless theory, we identify a region of parameter space where magnetic catalysis occurs at zero temperature but inverse magnetic catalysis at temperatures of order the thermal phase transition. The model shows similar non-monotonic behaviour in the condensate with B at intermediate T as the lattice data. This behaviour is due to the separation of the meson melting and chiral transitions in the holographic framework. The introduction of quark mass raises the scale of B where inverse catalysis takes over from catalysis until the inverse catalysis lies outside the regime of validity of the effective descr...

  18. The generation of myricetin-nicotinamide nanococrystals by top down and bottom up technologies.

    Science.gov (United States)

    Liu, Mingyu; Hong, Chao; Li, Guowen; Ma, Ping; Xie, Yan

    2016-09-30

    Myricetin-nicotinamide (MYR-NIC) nanococrystal preparation methods were developed and optimized using both top down and bottom up approaches. The grinding (top down) method successfully achieved nanococrystals, but there were some micrometer range particles and aggregation. The key consideration of the grinding technology was to control the milling time to determine a balance between the particle size and distribution. In contrast, a modified bottom up approach based on a solution method in conjunction with sonochemistry resulted in a uniform MYR-NIC nanococrystal that was confirmed by powder x-ray diffraction, scanning electron microscopy, dynamic light scattering, and differential scanning calorimeter, and the particle dissolution rate and amount were significantly greater than that of MYR-NIC cocrystal. Notably, this was a simple method without the addition of any non-solvent. We anticipate our findings will provide some guidance for future nanococrystal preparation as well as its application in both chemical and pharmaceutical area. PMID:27535365

  19. Bottom-up versus top-down effects on ciliate community composition in four eutrophic lakes (China).

    Science.gov (United States)

    Li, Jing; Chen, Feizhou; Liu, Zhengwen; Zhao, Xiuxia; Yang, Kun; Lu, Wenxuan; Cui, Kai

    2016-04-01

    Previous studies have shown that ciliate plankton is generally controlled by food resources (e.g., algae) and predators (e.g., metazooplankton). Among lakes with similar trophic levels but different distributions of phyto- and metazooplankton, the main forces acting on ciliate assemblages may be different. We investigated the relationship between ciliate communities and bottom-up versus top-down variables based on a survey of four subtropical eutrophic lakes (China). Two of the lakes (Chaohu, Taihu) are located on the Mid-lower Yangtze Plain near sea level, and the other two (Dianchi, Xingyunhu) on the Yunnan-Kweichow Plateau at 1700m above sea level. Blooms of cyanobacteria developed during summer in Lakes Chaohu and Taihu and throughout the year in Lakes Dianchi and Xingyunhu. Ciliate functional feeding groups differed significantly between lakes. The results of canonical correspondence analysis (CCA) and variation partitioning showed that cyanobacteria significantly influence ciliate species, whereas 'edible' algae (cryptophytes, diatoms) and cladocerans were the important variables in explaining the ciliate community structure of Lakes Dianchi and Xingyunhu compared with Lakes Taihu and Chaohu. Our results highlight the importance of consistent cyanobacterial blooms in shaping the ciliate community in subtropical eutrophic shallow lakes by interacting with top-down and bottom-up factors. PMID:26773905

  20. A Bottom-up Trend in Research of Management of Technology

    Directory of Open Access Journals (Sweden)

    Yoko Ishino

    2014-12-01

    Full Text Available Management of Technology (MOT is defined as an academic discipline of management that enables organizations to manage their technological fundamentals to create competitive advantage. MOT covers a wide range of contents including administrative strategy, R&D management, manufacturing management, technology transfer, production control, marketing, accounting, finance, business ethics, and others. For each topic, researchers have conducted their MOT research at various levels. However, a practical and pragmatic side of MOT surely affects its research trends. Finding changes of MOT research trends, or the chronological transitions of principal subjects, can help understand the key concepts of current MOT. This paper studied a bottom-up trend in research fields in MOT by applying a text-mining method to the conference proceedings of IAMOT (International Association for Management of Technology. First, focusing on only nouns found several keywords, which more frequently emerge over time in the IAMOT proceedings. Then, expanding the scope into other parts of speech viewed the keywords in a natural context. Finally, it was found that the use of an important keyword has qualitatively and quantitatively extended over time. In conclusion, a bottom-up trend in MOT research was detected and the effects of the social situation on the trend were discussed.Keywords: Management of Technology; Text Mining; Research Trend; Bottom-up Trend; Patent

  1. Making the results of bottom-up energy savings comparable

    Directory of Open Access Journals (Sweden)

    Moser Simon

    2012-01-01

    Full Text Available The Energy Service Directive (ESD has pushed forward the issue of energy savings calculations without clarifying the methodological basis. Savings achieved in the Member States are calculated with rather non-transparent and hardly comparable Bottom-up (BU methods. This paper develops the idea of parallel evaluation tracks separating the Member States’ issue of ESD verification and comparable savings calculations. Comparability is ensured by developing a standardised BU calculation kernel for different energy efficiency improvement (EEI actions which simultaneously depicts the different calculation options in a structured way (e.g. baseline definition, system boundaries, double counting. Due to the heterogeneity of BU calculations the approach requires a central database where Member States feed in input data on BU actions according to a predefined structure. The paper demonstrates the proposed approach including a concrete example of application.

  2. Bottom-Up Discrete Symmetries for Cabibbo Mixing

    CERN Document Server

    Varzielas, Ivo de Medeiros; Talbert, Jim

    2016-01-01

    We perform a bottom-up search for discrete non-Abelian symmetries capable of quantizing the Cabibbo angle that parameterizes CKM mixing. Given a particular Abelian symmetry structure in the up and down sectors, we construct representations of the associated residual generators which explicitly depend on the degrees of freedom present in our effective mixing matrix. We then discretize those degrees of freedom and utilize the Groups, Algorithms, Programming (GAP) package to close the associated finite groups. This short study is performed in the context of recent results indicating that, without resorting to special model-dependent corrections, no small-order finite group can simultaneously predict all four parameters of the three-generation CKM matrix and that only groups of $\\mathcal{O}(10^{2})$ can predict the analogous parameters of the leptonic PMNS matrix, regardless of whether neutrinos are Dirac or Majorana particles. Therefore a natural model of flavour might instead incorporate small(er) finite groups...

  3. BUEES:a bottom-up event extraction system

    Institute of Scientific and Technical Information of China (English)

    Xiao DING; Bing QIN; Ting LIU

    2015-01-01

    Traditional event extraction systems focus mainly on event type identifi cation and event participant extraction based on pre-specifi ed event type paradigms and manually annotated corpora. However, different domains have different event type paradigms. When transferring to a new domain, we have to build a new event type paradigm and annotate a new corpus from scratch. This kind of conventional event extraction system requires massive human effort, and hence prevents event extraction from being widely applicable. In this paper, we present BUEES, a bottom-up event extraction system, which extracts events from the web in a completely unsupervised way. The system automatically builds an event type paradigm in the input corpus, and then proceeds to extract a large number of instance patterns of these events. Subsequently, the system extracts event arguments according to these patterns. By conducting a series of experiments, we demonstrate the good performance of BUEES and compare it to a state-of-the-art Chinese event extraction system, i.e., a supervised event extraction system. Experimental results show that BUEES performs comparably (5% higher F-measure in event type identifi cation and 3% higher F-measure in event argument extraction), but without any human effort.

  4. Nonplanar conductive surfaces via "bottom-up" nanostructured gold coating.

    Science.gov (United States)

    Vinod, T P; Jelinek, Raz

    2014-03-12

    Development of technologies for the construction of bent, curved, and flexible conductive surfaces is among the most important albeit challenging goals in the promising field of "flexible electronics". We present a generic solution-based "bottom-up" approach for assembling conductive gold nanostructured layers on nonplanar polymer surfaces. The simple two-step experimental scheme is based upon incubation of an amine-displaying polymer [the abundantly used poly(dimethylsiloxane) (PDMS), selected here as a proof of concept] with Au(SCN)4(-), followed by a brief treatment with a conductive polymer [poly(3,4-thylenedioxythiophene)/poly(styrenesulfonate)] solution. Importantly, no reducing agent is co-added to the gold complex solution. The resultant surfaces are conductive and exhibit a unique "nanoribbon" gold morphology. The scheme yields conductive layers upon PDMS in varied configurations: planar, "wrinkled", and mechanically bent surfaces. The technology is simple, inexpensive, and easy to implement for varied polymer surfaces (and other substances), opening the way for practical applications in flexible electronics and related fields. PMID:24548243

  5. Bottom-Up Synthesis and Sensor Applications of Biomimetic Nanostructures

    Directory of Open Access Journals (Sweden)

    Li Wang

    2016-01-01

    Full Text Available The combination of nanotechnology, biology, and bioengineering greatly improved the developments of nanomaterials with unique functions and properties. Biomolecules as the nanoscale building blocks play very important roles for the final formation of functional nanostructures. Many kinds of novel nanostructures have been created by using the bioinspired self-assembly and subsequent binding with various nanoparticles. In this review, we summarized the studies on the fabrications and sensor applications of biomimetic nanostructures. The strategies for creating different bottom-up nanostructures by using biomolecules like DNA, protein, peptide, and virus, as well as microorganisms like bacteria and plant leaf are introduced. In addition, the potential applications of the synthesized biomimetic nanostructures for colorimetry, fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrical resistance, electrochemistry, and quartz crystal microbalance sensors are presented. This review will promote the understanding of relationships between biomolecules/microorganisms and functional nanomaterials in one way, and in another way it will guide the design and synthesis of biomimetic nanomaterials with unique properties in the future.

  6. Bottom-up Visual Integration in the Medial Parietal Lobe.

    Science.gov (United States)

    Pflugshaupt, Tobias; Nösberger, Myriam; Gutbrod, Klemens; Weber, Konrad P; Linnebank, Michael; Brugger, Peter

    2016-03-01

    Largely based on findings from functional neuroimaging studies, the medial parietal lobe is known to contribute to internally directed cognitive processes such as visual imagery or episodic memory. Here, we present 2 patients with behavioral impairments that extend this view. Both had chronic unilateral lesions of nearly the entire medial parietal lobe, but in opposite hemispheres. Routine neuropsychological examination conducted >4 years after the onset of brain damage showed little deficits of minor severity. In contrast, both patients reported persistent unusual visual impairment. A comprehensive series of tachistoscopic experiments with lateralized stimulus presentation and comparison with healthy participants revealed partial visual hemiagnosia for stimuli presented to their contralesional hemifield, applying inferential single-case statistics to evaluate deficits and dissociations. Double dissociations were found in 4 experiments during which participants had to integrate more than one visual element, either through comparison or formation of a global gestalt. Against the background of recent neuroimaging findings, we conclude that of all medial parietal structures, the precuneus is the most likely candidate for a crucial involvement in such bottom-up visual integration. PMID:25331599

  7. Bottom-Up Colloidal Crystal Assembly with a Twist.

    Science.gov (United States)

    Mahynski, Nathan A; Rovigatti, Lorenzo; Likos, Christos N; Panagiotopoulos, Athanassios Z

    2016-05-24

    Globally ordered colloidal crystal lattices have broad utility in a wide range of optical and catalytic devices, for example, as photonic band gap materials. However, the self-assembly of stereospecific structures is often confounded by polymorphism. Small free-energy differences often characterize ensembles of different structures, making it difficult to produce a single morphology at will. Current techniques to handle this problem adopt one of two approaches: that of the "top-down" or "bottom-up" methodology, whereby structures are engineered starting from the largest or smallest relevant length scales, respectively. However, recently, a third approach for directing high fidelity assembly of colloidal crystals has been suggested which relies on the introduction of polymer cosolutes into the crystal phase [Mahynski, N.; Panagiotopoulos, A. Z.; Meng, D.; Kumar, S. K. Nat. Commun. 2014, 5, 4472]. By tuning the polymer's morphology to interact uniquely with the void symmetry of a single desired crystal, the entropy loss associated with polymer confinement has been shown to strongly bias the formation of that phase. However, previously, this approach has only been demonstrated in the limiting case of close-packed crystals. Here, we show how this approach may be generalized and extended to complex open crystals, illustrating the utility of this "structure-directing agent" paradigm in engineering the nanoscale structure of ordered colloidal materials. The high degree of transferability of this paradigm's basic principles between relatively simple crystals and more complex ones suggests that this represents a valuable addition to presently known self-assembly techniques. PMID:27124487

  8. High thermoelectric figure of merit nanostructured pnictogen chalcogenides by bottom-up synthesis and assembly

    Science.gov (United States)

    Mehta, Rutvik J.

    Thermoelectric materials offer promise for realizing transformative environmentallyfriendly solid-state refrigeration technologies that could replace current technologies based on ozone-depleting liquid coolants. The fruition of this vision requires factorial enhancements in the figure of merit (ZT) of thermoelectric materials, necessitating high Seebeck coefficient (alpha), high electrical conductivity (sigma) and low thermal conductivity (kappa). This thesis reports a novel bottom-up approach to scalably sculpt large quantities (>10g/minute) of V 2VI3 nanocrystals with controllable shapes and sizes, and assemble them into bulk samples to obtain both high power factors alpha 2sigma as well as unprecedentedly low kappa through tunable doping and nanostructuring. The thesis demonstrates a surfactant-mediated microwave-solvothermal synthesis technique that selectively yields both n- and p-typed pnictogen chalcogenide (Bi2Te3, Sb2Te3, Bi2Se3) nanoplates and, nanowires and nanotubes (Sb 2Se3) that can be sintered to obtain 25-250 % increases in ZT>1 compared to their non-nanostructured and un-doped counterparts. A key result is that nanostructuring diminishes the lattice thermal conductivity kappa L to ultra-low values of 0.2-0.5 Wm-1K-1. Sub-atomic-percent sulfur doping and sulfurization of the pnictogen chalcogenides induced through mercaptan-terminated organic surfactants used in the synthesis result in large Seebeck coefficients between -240 nanocomposites by mixing nanoplates of different materials (e.g., S-doped Sb2Te3 and S-doped Bi2Te3) and forming heterostructures of metals and chalcogenides. The thesis finally demonstrates the extendibility of the novel synthesis and assembly approach to tailor the thermoelectric properties of other non-traditional thermoelectric materials systems.

  9. On the Temporal Relation of Top-Down and Bottom-Up Mechanisms during Guidance of Attention

    Science.gov (United States)

    Wykowska, Agnieszka; Schubo, Anna

    2010-01-01

    Two mechanisms are said to be responsible for guiding focal attention in visual selection: bottom-up, saliency-driven capture and top-down control. These mechanisms were examined with a paradigm that combined a visual search task with postdisplay probe detection. Two SOAs between the search display and probe onsets were introduced to investigate…

  10. NEMO. Netherlands Energy demand MOdel. A top-down model based on bottom-up information

    International Nuclear Information System (INIS)

    The title model links energy use to other production factors, (physical) production, energy prices, technological trends and government policies. It uses a 'putty-semiputty' vintage production structure, in which new investments, adaptations to existing capital goods (retrofit) and 'good-housekeeping' are discerned. Price elasticities are relatively large in the long term and small in the short term. Most predictions of energy use are based on either econometric models or on 'bottom-up information', i.e. disaggregated lists of technical possibilities for and costs of saving energy. Typically, one predicts more energy-efficiency improvements using bottom-up information than using econometric ('top-down') models. We bridged this so-called 'energy-efficiency gap' by designing our macro/meso model NEMO in such a way that we can use bottom-up (micro) information to estimate most model parameters. In our view, reflected in NEMO, the energy-efficiency gap arises for two reasons. The first is that firms and households use a fairly high discount rate of 15% when evaluating the profitability of energy-efficiency improvements. The second is that our bottom-up information ('ICARUS') for most economic sectors does not (as NEMO does) take account of the fact that implementation of new, energy-efficient technology in capital stock takes place only gradually. Parameter estimates for 19 sectors point at a long-term technological energy efficiency improvement trend in Netherlands final energy use of 0.8% per year. The long-term price elasticity is estimated to be 0.29. These values are comparable to other studies based on time series data. Simulations of the effects of the oil price shocks in the seventies and the subsequent fall of oil prices show that the NEMO's price elasticities are consistent with historical data. However, the present pace at which new technologies become available (reflected in NEMO) appears to be lower than in the seventies and eighties. This suggests that it

  11. Top-down and bottom-up definitions of human failure events in human reliability analysis

    Energy Technology Data Exchange (ETDEWEB)

    Boring, Ronald Laurids [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-10-01

    In the probabilistic risk assessments (PRAs) used in the nuclear industry, human failure events (HFEs) are determined as a subset of hardware failures, namely those hardware failures that could be triggered by human action or inaction. This approach is top-down, starting with hardware faults and deducing human contributions to those faults. Elsewhere, more traditionally human factors driven approaches would tend to look at opportunities for human errors first in a task analysis and then identify which of those errors is risk significant. The intersection of top-down and bottom-up approaches to defining HFEs has not been carefully studied. Ideally, both approaches should arrive at the same set of HFEs. This question is crucial, however, as human reliability analysis (HRA) methods are generalized to new domains like oil and gas. The HFEs used in nuclear PRAs tend to be top-down—defined as a subset of the PRA—whereas the HFEs used in petroleum quantitative risk assessments (QRAs) often tend to be bottom-up—derived from a task analysis conducted by human factors experts. The marriage of these approaches is necessary in order to ensure that HRA methods developed for top-down HFEs are also sufficient for bottom-up applications.

  12. Top-down (Prior Knowledge) and Bottom-up (Perceptual Modality) Influences on Spontaneous Interpersonal Synchronization.

    Science.gov (United States)

    Gipson, Christina L; Gorman, Jamie C; Hessler, Eric E

    2016-04-01

    Coordination with others is such a fundamental part of human activity that it can happen unintentionally. This unintentional coordination can manifest as synchronization and is observed in physical and human systems alike. We investigated the role of top-down influences (prior knowledge of the perceptual modality their partner is using) and bottom-up factors (perceptual modality combination) on spontaneous interpersonal synchronization. We examine this phenomena with respect to two different theoretical perspectives that differently emphasize top-down and bottom-up factors in interpersonal synchronization: joint-action/shared cognition theories and ecological-interactive theories. In an empirical study twelve dyads performed a finger oscillation task while attending to each other's movements through either visual, auditory, or visual and auditory perceptual modalities. Half of the participants were given prior knowledge of their partner's perceptual capabilities for coordinating across these different perceptual modality combinations. We found that the effect of top-down influence depends on the perceptual modality combination between two individuals. When people used the same perceptual modalities, top-down influence resulted in less synchronization and when people used different perceptual modalities, top-down influence resulted in more synchronization. Furthermore, persistence in the change in behavior as a result of having perceptual information about each other ('social memory') was stronger when this top-down influence was present. PMID:27033133

  13. Influence of top-down and bottom-up manipulations on the R-BT065 subcluster of Betaproteobacteria, an abundant group in bacterioplankton of a freshwater reservoir

    Czech Academy of Sciences Publication Activity Database

    Šimek, Karel; Horňák, Karel; Jezbera, Jan; Mašín, Michal; Nedoma, Jiří; Gasol, J. M. .; Schauer, M.

    2005-01-01

    Roč. 71, č. 5 (2005), s. 2381-2390. ISSN 0099-2240 R&D Projects: GA ČR(CZ) GA206/05/0007; GA ČR(CZ) GA206/02/0003 Grant ostatní: CSIC(ES) DGICYT REN2001-2120/MAR; EU(XE) EVK3-CT-2002-00078; Austrian Science Foundation(AT) P15655 Institutional research plan: CEZ:AV0Z60170517 Keywords : reservoir * top-down and bottom-up control * microbial food webs * bacterivory * bacterial community composition Subject RIV: EE - Microbiology, Virology Impact factor: 3.818, year: 2005

  14. Bottom-up formation of endohedral mono-metallofullerenes is directed by charge transfer

    Science.gov (United States)

    Dunk, Paul W.; Mulet-Gas, Marc; Nakanishi, Yusuke; Kaiser, Nathan K.; Rodríguez-Fortea, Antonio; Shinohara, Hisanori; Poblet, Josep M.; Marshall, Alan G.; Kroto, Harold W.

    2014-12-01

    An understanding of chemical formation mechanisms is essential to achieve effective yields and targeted products. One of the most challenging endeavors is synthesis of molecular nanocarbon. Endohedral metallofullerenes are of particular interest because of their unique properties that offer promise in a variety of applications. Nevertheless, the mechanism of formation from metal-doped graphite has largely eluded experimental study, because harsh synthetic methods are required to obtain them. Here we report bottom-up formation of mono-metallofullerenes under core synthesis conditions. Charge transfer is a principal factor that guides formation, discovered by study of metallofullerene formation with virtually all available elements of the periodic table. These results could enable production strategies that overcome long-standing problems that hinder current and future applications of metallofullerenes.

  15. Bottom-up design of 2D organic photocatalysts for visible-light driven hydrogen evolution

    Science.gov (United States)

    Wang, Peng; Jiang, Xue; Zhao, Jijun

    2016-01-01

    To design two-dimensional (2D) organocatalysts, three series of covalent organic frameworks (COFs) are constructed using bottom-up strategies, i.e. molecular selection, tunable linkage, and functionalization. First-principles calculations are performed to confirm their photocatalytic activity under visible light. Two of our constructed 2D COF models (B1 and C3) are identified as a sufficiently efficient organocatalyst for visible light water splitting. The controllable construction of such COFs from suitable organic subunit, linkage, and functional groups paves the way for correlating band edge alignments and geometry parameters of 2D organic materials. Our theoretical prediction not only provides essential insights into designing 2D-COF photocatalysts for water splitting, but also sparks other technological applications for 2D organic materials.

  16. Bottom-up design of 2D organic photocatalysts for visible-light driven hydrogen evolution

    International Nuclear Information System (INIS)

    To design two-dimensional (2D) organocatalysts, three series of covalent organic frameworks (COFs) are constructed using bottom-up strategies, i.e. molecular selection, tunable linkage, and functionalization. First-principles calculations are performed to confirm their photocatalytic activity under visible light. Two of our constructed 2D COF models (B1 and C3) are identified as a sufficiently efficient organocatalyst for visible light water splitting. The controllable construction of such COFs from suitable organic subunit, linkage, and functional groups paves the way for correlating band edge alignments and geometry parameters of 2D organic materials. Our theoretical prediction not only provides essential insights into designing 2D-COF photocatalysts for water splitting, but also sparks other technological applications for 2D organic materials. (paper)

  17. Effects of pollutants on bottom-up and top-down processes in insect-plant interactions

    International Nuclear Information System (INIS)

    Bottom-up (host plant quality) and top-down (natural enemies) forces both influence the fitness and population dynamics of herbivores. However, the impact of pollutants acting on these forces has not been examined, which prompted us to review the literature to test hypotheses regarding this area of research. A comprehensive literature search found 126 references which examined fitness components and population dynamics of 203 insect herbivores. One hundred and fifty-three of the 203 herbivores (75.4%) had fitness impacted due to bottom-up factors in polluted environments. In contrast, only 20 of the 203 (9.9%) had fitness significantly impacted due to top-down factors in polluted environments. The paucity of results for top-down factors impacting fitness does not necessarily mean that top-down factors are less important, but rather that fewer studies include natural enemies. We provide a synthesis of available data by pollution type and herbivore guild, and suggest future research to address this issue. - Pollutants can affect insect herbivores through bottom-up and, possibly, top-down processes

  18. Bottom-up communication. Identifying opportunities and limitations through an exploratory field-based evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, C.; Irvine, K.N. [Institute of Energy and Sustainable Development, De Montfort University, Leicester, LE1 9BH (United Kingdom)

    2013-02-15

    Communication to promote behaviours like energy saving can use significant resources. What is less clear is the comparative value of different approaches available to communicators. While it is generally agreed that 'bottom-up' approaches, where individuals are actively involved rather than passive, are preferable to 'top-down' authority-led projects, there is a dearth of evidence that verifies why this should be. Additionally, while the literature has examined the mechanics of the different approaches, there has been less attention paid to the associated psychological implications. This paper reports on an exploratory comparative study that examined the effects of six distinct communication activities. The activities used different communication approaches, some participative and others more top-down informational. Two theories, from behavioural studies and communication, were used to identify key variables for consideration in this field-based evaluation. The evaluation aimed to assess not just which activity might be most successful, as this has limited generalisability, but to also gain insight into what psychological impacts might contribute to success. Analysis found support for the general hypothesis that bottom-up approaches have more impact on behaviour change than top-down. The study also identified that, in this instance, the difference in reported behaviour across the activities related partly to the extent to which intentions to change behaviour were implemented. One possible explanation for the difference in reported behaviour change across the activities is that a bottom-up approach may offer a supportive environment where participants can discuss progress with like-minded individuals. A further possible explanation is that despite controlling for intention at an individual level, the pre-existence of strong intentions may have an effect on group success. These suggestive findings point toward the critical need for additional and larger-scale studies

  19. A bottom up approach for engineering catchments through sustainable runoff management

    Science.gov (United States)

    Wilkinson, M.; Quinn, P. F.; Jonczyk, J.; Burke, S.

    2010-12-01

    developed that puts in place novel measures to tackle diffuse pollution and reduce flood risk whilst collecting the science needed to influence the policy about these measures. This has been possible through four key practices: full stakeholder engagement, a problem solving agenda set in place, a bottom up approach to solving problems, and the collection of the appropriate science to support the benefits. Hands on, multi-objective work is the most cost effective way to manage catchments. Tackling water quality issues and controlling fast pathway runoff at the source in partnership with farmers and local landowners has proved to be the key to success. Tackling issues in sub-catchments can lead to solving problems at the catchment scale.

  20. A bottom-up approach of stochastic demand allocation in water quality modelling

    Directory of Open Access Journals (Sweden)

    E. J. M. Blokker

    2010-04-01

    Full Text Available An "all pipes" hydraulic model of a drinking water distribution system was constructed with two types of demand allocations. One is constructed with the conventional top-down approach, i.e. a demand multiplier pattern from the booster station is allocated to all demand nodes with a correction factor to account for the average water demand on that node. The other is constructed with a bottom-up approach of demand allocation, i.e., each individual home is represented by one demand node with its own stochastic water demand pattern. This was done for a drinking water distribution system of approximately 10 km of mains and serving ca. 1000 homes. The system was tested in a real life situation.

    The stochastic water demand patterns were constructed with the end-use model SIMDEUM on a per second basis and per individual home. Before applying the demand patterns in a network model, some temporal aggregation was done. The flow entering the test area was measured and a tracer test with sodium chloride was performed to determine travel times. The two models were validated on the total sum of demands and on travel times.

    The study showed that the bottom-up approach leads to realistic water demand patterns and travel times, without the need for any flow measurements or calibration. In the periphery of the drinking water distribution system it is not possible to calibrate models on pressure, because head losses are too low. The study shows that in the periphery it is also difficult to calibrate on water quality (e.g. with tracer measurements, as a consequence of the high variability between days. The stochastic approach of hydraulic modelling gives insight into the variability of travel times as an added feature beyond the conventional way of modelling.

  1. Emulating biology: Building nanostructures from the bottom up

    OpenAIRE

    Seeman, Nadrian C.; Belcher, Angela M.

    2002-01-01

    The biological approach to nanotechnology has produced self-assembled objects, arrays and devices; likewise, it has achieved the recognition of inorganic systems and the control of their growth. Can these approaches now be integrated to produce useful systems?

  2. Scaling up self-assembly: bottom-up approaches to macroscopic particle organization.

    Science.gov (United States)

    Lash, M H; Fedorchak, M V; McCarthy, J J; Little, S R

    2015-07-28

    This review presents an overview of recent work in the field of non-Brownian particle self-assembly. Compared to nanoparticles that naturally self-assemble due to Brownian motion, larger, non-Brownian particles (d > 6 μm) are less prone to autonomously organize into crystalline arrays. The tendency for particle systems to experience immobilization and kinetic arrest grows with particle radius. In order to overcome this kinetic limitation, some type of external driver must be applied to act as an artificial "thermalizing force" upon non-Brownian particles, inducing particle motion and subsequent crystallization. Many groups have explored the use of various agitation methods to overcome the natural barriers preventing self-assembly to which non-Brownian particles are susceptible. The ability to create materials from a bottom-up approach with these characteristics would allow for precise control over their pore structure (size and distribution) and surface properties (topography, functionalization and area), resulting in improved regulation of key characteristics such as mechanical strength, diffusive properties, and possibly even photonic properties. This review will highlight these approaches, as well as discuss the potential impact of bottom-up macroscale particle assembly. The applications of such technology range from customizable and autonomously self-assembled niche microenvironments for drug delivery and tissue engineering to new acoustic dampening, battery, and filtration materials, among others. Additionally, crystals made from non-Brownian particles resemble naturally derived materials such as opals, zeolites, and biological tissue (i.e. bone, cartilage and lung), due to their high surface area, pore distribution, and tunable (multilevel) hierarchy. PMID:25947543

  3. Washback from the Bottom-Up: A Grounded Theory

    OpenAIRE

    Seyyed Ali Ostovar-Namaghi

    2013-01-01

    Theory-driven wash back studies inculcate the view that tests are the only causal factor determining what teachers and students do and as such ignore other local constraints. This data-driven study aims at filling in the gap in the wash back knowledge-base by conceptualizing teachers’ perceptions of the university entrance exam (UEE) in Iran. In line with grounded theory, theoretically relevant concepts were sampled from qualitative interviews with experienced language teachers who were willi...

  4. Bottom-up nanofabrication using self-organized porous templates

    International Nuclear Information System (INIS)

    The great advances in nanoscience and nanotechnology in the last decade have led to the development of new platforms where all physical properties such as size, porosity, geometry and surface can be controlled at the nanoscale. Self-organized nanostructuring using template synthesis is a very promising and rapidly expanding field for the preparation of many different ordered structures ranging from the micrometer to the nanometer size. Porous aluminium, titanium, iron or hafnium oxide templates demonstrated real potential as well-controlled self-organized nanostructured materials for various applications. They are also an elegant tool to fabricate two- or three-dimensional arrays of periodic nanostructures. This work presents detailed methods to implement and fabricate nanoporous templates by anodic oxidation of Al and Ti metal substrates (that can be further used for Fe or Hf anodization). The characterization of nanowires grown in the pores of the synthesized Al2O3 and TiO2 templates is also discussed.

  5. Mapping practices of project management – merging top-down and bottom-up perspectives

    DEFF Research Database (Denmark)

    Thuesen, Christian

    2015-01-01

    This paper presents a new methodology for studying different accounts of project management practices based on network mapping and analysis. Drawing upon network mapping and visualization as an analytical strategy top-down and bottom-up accounts of project management practice are analysed and...... promising strategy for visualizing and analysing different accounts of project management practices....... compared. The analysis initially reveals a substantial difference between the top-down and bottom-up accounts of practice. Furthermore it identifies a soft side of project management that is central in the bottom-up account but absent from the top-down. Finally, the study shows that network mapping is a...

  6. Cooperation between Top-Down and Bottom-Up Theorem Provers by Subgoal Clause Transfer

    OpenAIRE

    Fuchs, Dirk

    1999-01-01

    Top-down and bottom-up theorem proving approaches have each specific ad-vantages and disadvantages. Bottom-up provers profit from strong redundancycontrol and suffer from the lack of goal-orientation, whereas top-down provers aregoal-oriented but have weak calculi when their proof lengths are considered. Inorder to integrate both approaches our method is to achieve cooperation betweena top-down and a bottom-up prover: The top-down prover generates subgoalclauses, then they are processed by a ...

  7. Optimizing the OR: a bottom-up approach.

    Science.gov (United States)

    Sohrakoff, Katrina; Westlake, Carrie; Key, Elizabeth; Barth, Elizabeth; Antognini, Joseph; Johnson, Vincent

    2014-01-01

    Efficiency in the operating room (OR) has important implications on finances, access, and patient and staff satisfaction. UC Davis Medical Center (UCDMC) launched an initiative to increase OR efficiency by using multidisciplinary staff-based teams. The initiative freed up 5,500 annual hours-about 1 hr per operating room per day-in the OR by improving the percentage of first case on-time starts, reducing OR turnover times, improving scheduling predictability and reducing the number of controllable cancellations. Importantly, the process also engrained a continuous quality improvement mentality into the medical center's culture. PMID:24926736

  8. Washback from the Bottom-Up: A Grounded Theory

    Directory of Open Access Journals (Sweden)

    Seyyed Ali Ostovar-Namaghi

    2013-11-01

    Full Text Available Theory-driven wash back studies inculcate the view that tests are the only causal factor determining what teachers and students do and as such ignore other local constraints. This data-driven study aims at filling in the gap in the wash back knowledge-base by conceptualizing teachers’ perceptions of the university entrance exam (UEE in Iran. In line with grounded theory, theoretically relevant concepts were sampled from qualitative interviews with experienced language teachers who were willing to share their views with the researcher. Iterative data collection and analysis revealed: (1 a set of local conditions that that make teachers shift away from language teaching towards preparing students for the UEE; (2 how the UEE deprives the nation from professional workforce by deprofessionalizing language teachers and producing a hose of communicatively incompetent high school graduates; and (3 data-driven suggestions for reform.Keywords: wash back, grounded theory, deprofessionalization, local conditions, communicatively-incompetent

  9. A bottom-up approach to data annotation in neurophysiology

    Directory of Open Access Journals (Sweden)

    Jan Grewe

    2011-08-01

    Full Text Available Metadata providing information about the stimulus, data acquisition, and experimentalconditions are indispensable for the analysis and management of experimental data withina lab. However, only rarely are metadata available in a structured, comprehensive, andmachine-readable form. This poses a severe problem for finding and retrieving data, bothin the laboratory and on the various emerging public data bases. Here, we propose a simpleformat, the Open metaData Markup Language (od ML, for collecting and exchangingmetadata in an automated, computer-based fashion. In od ML arbitrary metadata informa-tion is stored as extended key-value pairs in a hierarchical structure. Central to od ML isa clear separation of format and content, i.e. neither keys nor values are defined by theformat. This makes od ML flexible enough for storing all available metadata instantly with-out the necessity to submit new keys to an ontology or controlled terminology. Commonstandard keys can be defined in od ML terminologies for guaranteeing interoperability. Westarted to define such terminologies for neurophysiological data, but aim at a communitydriven extension and refinement of the proposed definitions. By customized terminologiesthat map to these standard terminologies, metadata can be named and organized as requiredor preferred without softening the standard. Together with the respective libraries providedfor common programming languages, the od ML format can be integrated into the labora-tory workflow, facilitating automated collection of metadata information where it becomesavailable. The flexibility of od ML also encourages a community driven collection anddefinition of terms used for annotating data in the neurosciences.

  10. A process to develop operational bottom-up evaluation methods - from reference guidebooks to a practical culture of evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Broc, Jean-Sebastien; Bourges, Bernard [Ecole des Mines de Nantes (DSEE) (France); Adnot, Jerome [Ecole des Mines de Paris, Centre of Energy and Processes (France)

    2007-07-01

    Needs for evaluating energy efficiency (EE) activities are increasing, for the accounting of results and for understanding their success/failures. Indeed evaluation results should be used for both reporting past activities and improving future operations. Lack of easy to use methods is pointed out by local stakeholders as a major barrier to evaluation. Another issue is the frequent negative perception of evaluation, experienced as a control and/or a waste of time.This paper presents a systematic process to develop bottom-up evaluation methods designed to fit to stakeholders needs: directly operational, easy to appropriate, providing useful conclusions to improve operations and to communicate about their results.Our approach relies on the principle of experience capitalisation and on an organisation with two levels, central and on-field. It aims to create conditions for continuous improvement. Moreover it should insure involved stakeholders do actually take part in and take advantage of the evaluation process. This methodology handles both impact and process evaluation. For the impacts, focus is on calculations transparency, data quality and reliability of the results. Regarding operation process, main issues are analysing causality between actions and results, and detecting the success and failure factors.This work was first developed for the evaluation of local operations in France. The resulting methodology was tested on two case studies from the Eco Energy Plan, a local EE programme implemented in South-East of France.

  11. Social and ethical checkpoints for bottom-up synthetic biology, or protocells.

    Science.gov (United States)

    Bedau, Mark A; Parke, Emily C; Tangen, Uwe; Hantsche-Tangen, Brigitte

    2009-12-01

    An alternative to creating novel organisms through the traditional "top-down" approach to synthetic biology involves creating them from the "bottom up" by assembling them from non-living components; the products of this approach are called "protocells." In this paper we describe how bottom-up and top-down synthetic biology differ, review the current state of protocell research and development, and examine the unique ethical, social, and regulatory issues raised by bottom-up synthetic biology. Protocells have not yet been developed, but many expect this to happen within the next five to ten years. Accordingly, we identify six key checkpoints in protocell development at which particular attention should be given to specific ethical, social and regulatory issues concerning bottom-up synthetic biology, and make ten recommendations for responsible protocell science that are tied to the achievement of these checkpoints. PMID:19816801

  12. The updated bottom up solution applied to atmospheric pressure photoionization and electrospray ionization mass spectrometry

    Science.gov (United States)

    The Updated Bottom Up Solution (UBUS) was recently applied to atmospheric pressure chemical ionization (APCI) mass spectrometry (MS) of triacylglycerols (TAGs). This report demonstrates that the UBUS applies equally well to atmospheric pressure photoionization (APPI) MS and to electrospray ionizatio...

  13. A Bottom up Initiative: Meditation & Mindfulness 'Eastern' Practices in the "Western" Academia

    DEFF Research Database (Denmark)

    Singla, Rashmi

    case of bottom up initiative, where the students themselves have demanded inclusion of non- conventional psychosocial interventions illustrated by meditation and mindfulness as Eastern psychological practices, thus filling the gap related to the existential, spiritual approaches. The western...

  14. The Chicago Fire of 1871: A Bottom Up Approach to Disaster Relief

    OpenAIRE

    Emily C. Skarbek

    2014-01-01

    Can bottom-up relief efforts lead to recovery after disasters? Conventional wisdom and contemporary public policy suggest that major crises require centralized authority to provide disaster relief goods. Using a novel set of comprehensive donation and expenditure data collected from archival records, this paper examines a bottom-up relief effort following one of the most devastating natural disasters of the nineteenth century: the Chicago Fire of 1871. Findings show that while there was no ce...

  15. A Critique of 'Bottom-up' Peacebuilding: Do Peaceful Individuals Make Peaceful Societies?

    OpenAIRE

    Lefranc, Sandrine

    2011-01-01

    This chapter is concerned with dialogue-based post-conflict practices currently being promoted vigorously by certain international organizations. On the one hand, there is "transitional justice" with its cornerstone forums, deemed truth and reconciliation commissions. On the other hand, there are various "bottom-up" peacebuilding techniques (local dialogues, coexistence programs, conflict resolution training, and so on). Generally speaking, these "bottom-up" approaches work to transform indiv...

  16. Mapping practices of project management – merging top-down and bottom-up perspectives

    OpenAIRE

    Thuesen, Christian

    2015-01-01

    This paper presents a new methodology for studying different accounts of project management practices based on network mapping and analysis. Drawing upon network mapping and visualization as an analytical strategy top-down and bottom-up accounts of project management practice are analysed and compared. The analysis initially reveals a substantial difference between the top-down and bottom-up accounts of practice. Furthermore it identifies a soft side of project management that is central in t...

  17. Methane and ethane from global oil and gas production: bottom-up simulations over three decades

    OpenAIRE

    Höglund-Isaksson, L.

    2016-01-01

    Existing bottom-up emission inventories of historical methane and ethane emissions from global oil and gas systems do not well explain year-on-year variations estimated by top-down models from atmospheric measurements. This paper develops a bottom-up methodology which allows for country- and year specific source attribution of methane and ethane emissions from global oil and natural gas production for the period 1980 to 2012. The analysis rests on country-specific simulations of associated ga...

  18. Vasculogenic potential evaluation of bottom-up, PCL scaffolds guiding early angiogenesis in tissue regeneration.

    Science.gov (United States)

    Rossi, L; Attanasio, C; Vilardi, E; De Gregorio, M; Netti, P A

    2016-06-01

    Vascularization is a key factor in the successful integration of tissue engineered (TE) grafts inside the host body. Biological functions of the newly formed tissue depend, in fact, on a reliable and fast spread of the vascular network inside the scaffold. In this study, we propose a technique for evaluating vascularization in TE constructs assembled by a bottom-up approach. The rational, ordered assembly of building blocks (BBs) into a 3D scaffold can improve vessel penetration, and-unlike most current technologies-is compatible with the insertion of different elements that can be designed independently (e.g. structural units, growth factor depots etc.). Poly(ε-caprolactone) scaffolds composed of orderly and randomly assembled sintered microspheres were used to assess the degree of vascularization in a pilot in vivo study. Scaffolds were implanted in a rat subcutaneous pocket model, and retrieved after 7 days. We introduce three quantitative factors as a measure of vascularization: the total percentage of vascularization, the vessels diameter distribution and the vascular penetration depth. These parameters were derived by image analysis of microcomputed tomographic scans of biological specimens perfused with a radiopaque polymer. The outcome of this study suggests that the rational assembly of BBs helps the onset and organization of a fully functional vascular network. PMID:27117793

  19. Bottoms Up

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China’s high-end liquor is becoming a luxury item and a favorite among collectors spring Festival, the most important festival for the Chinese, is a time for celebration—and what would a celebration be without bottles of holi-

  20. Top-down and bottom-up regulation of macroalgal community structure on a Kenyan reef

    Science.gov (United States)

    Mörk, Erik; Sjöö, Gustaf Lilliesköld; Kautsky, Nils; McClanahan, Tim R.

    2009-09-01

    Top-down and bottom-up regulation in the form of grazing by herbivores and nutrient availability are important factors governing macroalgal communities in the coral reef ecosystem. Today, anthropogenic activities, such as over-harvesting of herbivorous fish and sea urchins and increased nutrient loading, are altering the interaction of these two structuring forces. The present study was conducted in Kenya and investigates the relative importance of herbivory and nutrient loading on macroalgal community dynamics, by looking at alterations in macroalgal functional groups, species diversity ( H') and biomass within experimental quadrats. The experiment was conducted in situ for 42 days during the dry season. Cages excluding large herbivorous fish and sea urchins were used in the study and nutrient addition was conducted using coated, slow-release fertilizer (nitrogen and phosphorous) at a site where herbivory is generally low and nutrient levels are relatively high for the region. Nutrient addition increased tissue nutrient content in the algae, and fertilized quadrats had 24% higher species diversity. Herbivore exclusion resulted in a 77% increase in algal biomass, mainly attributable to a >1000% increase in corticated forms. These results are in accordance with similar studies in other regions, but are unique in that they indicate that, even when prevailing nutrient levels are relatively high and herbivore pressure is relatively low, continued anthropogenic disturbance results in further ecological responses and increased reef degradation.

  1. Rational design of modular circuits for gene transcription: A test of the bottom-up approach

    Directory of Open Access Journals (Sweden)

    Giordano Emanuele

    2010-11-01

    Full Text Available Abstract Background Most of synthetic circuits developed so far have been designed by an ad hoc approach, using a small number of components (i.e. LacI, TetR and a trial and error strategy. We are at the point where an increasing number of modular, inter-changeable and well-characterized components is needed to expand the construction of synthetic devices and to allow a rational approach to the design. Results We used interchangeable modular biological parts to create a set of novel synthetic devices for controlling gene transcription, and we developed a mathematical model of the modular circuits. Model parameters were identified by experimental measurements from a subset of modular combinations. The model revealed an unexpected feature of the lactose repressor system, i.e. a residual binding affinity for the operator site by induced lactose repressor molecules. Once this residual affinity was taken into account, the model properly reproduced the experimental data from the training set. The parameters identified in the training set allowed the prediction of the behavior of networks not included in the identification procedure. Conclusions This study provides new quantitative evidences that the use of independent and well-characterized biological parts and mathematical modeling, what is called a bottom-up approach to the construction of gene networks, can allow the design of new and different devices re-using the same modular parts.

  2. A Bottom-Up Engineered Broadband Optical Nanoabsorber for Radiometry and Energy Harnessing Applications

    Science.gov (United States)

    Kaul, Anupama B.; Coles, James B.; Megerian, Krikor G.; Eastwood, Michael; Green, Robert O.; Bandaru, Prabhakar R.

    2013-01-01

    Optical absorbers based on vertically aligned multi-walled carbon nanotubes (MWCNTs), synthesized using electric-field assisted growth, are described here that show an ultra-low reflectance, 100X lower compared to Au-black from wavelength lamba approximately 350 nm - 2.5 micron. A bi-metallic Co/Ti layer was shown to catalyze a high site density of MWCNTs on metallic substrates and the optical properties of the absorbers were engineered by controlling the bottom-up synthesis conditions using dc plasma-enhanced chemical vapor deposition (PECVD). Reflectance measurements on the MWCNT absorbers after heating them in air to 400deg showed negligible changes in reflectance which was still low, approximately 0.022 % at lamba approximately 2 micron. In contrast, the percolated structure of the reference Au-black samples collapsed completely after heating, causing the optical response to degrade at temperatures as low as 200deg. The high optical absorption efficiency of the MWCNT absorbers, synthesized on metallic substrates, over a broad spectral range, coupled with their thermal ruggedness, suggests they have promise in solar energy harnessing applications, as well as thermal detectors for radiometry.

  3. Modeling Visual Exploration in Rhesus Macaques with Bottom-Up Salience and Oculomotor Statistics

    Science.gov (United States)

    König, Seth D.; Buffalo, Elizabeth A.

    2016-01-01

    There is a growing interest in studying biological systems in natural settings, in which experimental stimuli are less artificial and behavior is less controlled. In primate vision research, free viewing of complex images has elucidated novel neural responses, and free viewing in humans has helped discover attentional and behavioral impairments in patients with neurological disorders. In order to fully interpret data collected from free viewing of complex scenes, it is critical to better understand what aspects of the stimuli guide viewing behavior. To this end, we have developed a novel viewing behavior model called a Biased Correlated Random Walk (BCRW) to describe free viewing behavior during the exploration of complex scenes in monkeys. The BCRW can predict fixation locations better than bottom-up salience. Additionally, we show that the BCRW can be used to test hypotheses regarding specific attentional mechanisms. For example, we used the BCRW to examine the source of the central bias in fixation locations. Our analyses suggest that the central bias may be caused by a natural tendency to reorient the eyes toward the center of the stimulus, rather than a photographer's bias to center salient items in a scene. Taken together these data suggest that the BCRW can be used to further our understanding of viewing behavior and attention, and could be useful in optimizing stimulus and task design.

  4. Fabricating ordered functional nanostructures onto polycrystalline substrates from the bottom-up

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Maria, E-mail: mtorres@drexel.edu; Pardo, Lorena; Ricote, Jesus [Instituto de Ciencia de Materiales de Madrid (Spain); Fuentes-Cobas, Luis E. [Centro de Investigacion en Materiales Avanzados (Mexico); Rodriguez, Brian J. [University College Dublin, Belfield, School of Physics (Ireland); Calzada, M. Lourdes, E-mail: lcalzada@icmm.csic.es [Instituto de Ciencia de Materiales de Madrid (Spain)

    2012-10-15

    Microemulsion-mediated synthesis has emerged as a powerful bottom-up procedure for the preparation of ferroelectric nanostructures onto substrates. However, periodical order has yet to be achieved onto polycrystalline Pt-coated Si substrates. Here, we report a new methodology that involves microemulsion-mediated synthesis and the controlled modification of the surface of the substrate by coating it with a template-layer of water-micelles. This layer modifies the surface tension of the substrate and yields a periodic arrangement of ferroelectric crystalline nanostructures. The size of the nanostructures is decreased to the sub-50 nm range and they show a hexagonal order up to the third neighbors, which corresponds to a density of 275 Gb in{sup -2}. The structural analysis of the nanostructures by synchrotron X-ray diffraction confirms that the nanostructures have a PbTiO{sub 3} perovskite structure, with lattice parameters of a = b = 3.890(0) A and c = 4.056(7) A. Piezoresponse force microscopy confirmed the ferro-piezoelectric character of the nanostructures. This simple methodology is valid for the self-assembly of other functional oxides onto polycrystalline substrates, enabling their reliable integration into micro/nano devices.

  5. Bottom-up learning of hierarchical models in a class of deterministic POMDP environments

    Directory of Open Access Journals (Sweden)

    Itoh Hideaki

    2015-09-01

    Full Text Available The theory of partially observable Markov decision processes (POMDPs is a useful tool for developing various intelligent agents, and learning hierarchical POMDP models is one of the key approaches for building such agents when the environments of the agents are unknown and large. To learn hierarchical models, bottom-up learning methods in which learning takes place in a layer-by-layer manner from the lowest to the highest layer are already extensively used in some research fields such as hidden Markov models and neural networks. However, little attention has been paid to bottom-up approaches for learning POMDP models. In this paper, we present a novel bottom-up learning algorithm for hierarchical POMDP models and prove that, by using this algorithm, a perfect model (i.e., a model that can perfectly predict future observations can be learned at least in a class of deterministic POMDP environments

  6. Integrated Assessment of Energy Policies: A Decomposition of Top-Down and Bottom-Up

    Energy Technology Data Exchange (ETDEWEB)

    Boehringer, Christoph (Univ. of Oldenburg (Germany)); Rutherford, Thomas F. (ETH Zuerich (Switzerland))

    2008-01-15

    The formulation of market equilibrium problems as mixed complementarity problems (MCP) permits integration of bottom-up programming models of the energy system into top-down general equilibrium models of the overall economy. Yet, in practise the MCP approach loses analytical tractability of income effects, when the energy system includes upper and lowrbounds on many decision variables . We therefore advocate the use of complementarity methods to solve only the top-down economic equilibrium model and employ quadratic programming to solve the underlying bottom-up energy supply model. A simple iterative procedure reconciles the equilibrium prices and quantities between both models.

  7. Increased performance in a bottom-up designed robot by experimentally guided redesign

    DEFF Research Database (Denmark)

    Larsen, Jørgen Christian

    2013-01-01

    Purpose – Using a bottom-up, model-free approach when building robots is often seen as a less scientific way, compared to a top-down model-based approach, because the results are not easily generalizable to other systems. The authors, however, hypothesize that this problem may be addressed by using...... solid experimental methods. The purpose of this paper is to show how well-known experimental methods from bio-mechanics are used to measure and locate weaknesses in a bottom-up, model-free implementation of a quadruped walker and come up with a better solution. Design/methodology/approach – To study the...

  8. Fast and bottom-up object detection, segmentation, and evaluation using gestalt principles

    OpenAIRE

    Kootstra G.; Kragic D.

    2011-01-01

    In many scenarios, domestic robot will regularly encounter unknown objects. In such cases, top-down knowledge about the object for detection, recognition, and classification cannot be used. To learn about the object, or to be able to grasp it, bottom-up object segmentation is an important competence for the robot. Also when there is top-down knowledge, prior segmentation of the object can improve recognition and classification. In this paper, we focus on the problem of bottom-up detection and...

  9. TMS-induced theta phase synchrony reveals a bottom-up network in working memory.

    Science.gov (United States)

    Miyauchi, Eri; Kitajo, Keiichi; Kawasaki, Masahiro

    2016-05-27

    Global theta phase synchronization between the frontal and sensory areas has been suggested to connect the relevant areas for executive processes of working memory (WM). However, little is known regarding network directionality (i.e. top-down or bottom-up) of this interaction. To address the issue, the present study conducted transcranial magnetic stimulation (TMS)-electroencephalography (EEG) experiment during WM tasks. Results showed that TMS-induced increases in theta phase synchronization were observed only when TMS was delivered to the sensory areas but not the frontal area. These findings suggest that network directionality represented in WM is bottom-up rather than top-down. PMID:27063284

  10. Social and ethical checkpoints for bottom-up synthetic biology, or protocells

    OpenAIRE

    Bedau M.A.; Parke E.C.; Tangen U.; Hantsche-Tangen B.

    2009-01-01

    An alternative to creating novel organisms through the traditional “top-down” approach to synthetic biology involves creating them from the “bottom up” by assembling them from non-living components; the products of this approach are called “protocells.” In this paper we describe how bottom-up and top-down synthetic biology differ, review the current state of protocell research and development, and examine the unique ethical, social, and regulatory issues raised by bottom-up synthetic biology....

  11. A bottom-up model to describe consumers’ preferences towards late season peaches

    OpenAIRE

    Etiénne Groot; Luis M. Albisu

    2015-01-01

    Peaches are consumed in Mediterranean countries since ancient times. Nowadays there are few areas in Europe that produce peaches with Protected Designation of Origin (PDO), and the Calanda area is one of them. The aim of this work is to describe consumers’ preferences towards late season PDO Calanda peaches in the city of Zaragoza, Spain, by a bottom-up model. The bottom-up model proves greater amount of information than top-down models. In this approach it is estimated one utility function p...

  12. Quantifying the uncertainties of a bottom-up emission inventory of anthropogenic atmospheric pollutants in China

    Directory of Open Access Journals (Sweden)

    Y. Zhao

    2010-11-01

    Full Text Available The uncertainties of a national, bottom-up inventory of Chinese emissions of anthropogenic SO2, NOx, and particulate matter (PM of different size classes and carbonaceous species are comprehensively quantified, for the first time, using Monte Carlo simulation. The inventory is structured by seven dominant sectors: coal-fired electric power, cement, iron and steel, other industry (boiler combustion, other industry (non-combustion processes, transportation, and residential. For each parameter related to emission factors or activity-level calculations, the uncertainties, represented as probability distributions, are either statistically fitted using results of domestic field tests or, when these are lacking, estimated based on foreign or other domestic data. The uncertainties (i.e., 95% confidence intervals around the central estimates of Chinese emissions of SO2, NOx, total PM, PM10, PM2.5, black carbon (BC, and organic carbon (OC in 2005 are estimated to be −14%~12%, −10%~36%, −10%~36%, −12%~42% −16%~52%, −23%~130%, and −37%~117%, respectively. Variations at activity levels (e.g., energy consumption or industrial production are not the main source of emission uncertainties. Due to narrow classification of source types, large sample sizes, and relatively high data quality, the coal-fired power sector is estimated to have the smallest emission uncertainties for all species except BC and OC. Due to poorer source classifications and a wider range of estimated emission factors, considerable uncertainties of NOx and PM emissions from cement production and boiler combustion in other industries are found. The probability distributions of emission factors for biomass burning, the largest source of BC and OC, are fitted based on very limited domestic field measurements, and special caution should thus be taken interpreting these emission uncertainties. Although Monte

  13. An integrated top-down and bottom-up strategy for characterization protein isoforms and modifications

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Si; Tolic, Nikola; Tian, Zhixin; Robinson, Errol W.; Pasa-Tolic, Ljiljana

    2011-04-15

    Bottom-up and top-down strategies are two commonly used methods for mass spectrometry (MS) based protein identification; each method has its own advantages and disadvantages. In this chapter, we describe an integrated top-down and bottom-up approach facilitated by concurrent liquid chromatography-mass spectrometry (LC-MS) analysis and fraction collection for comprehensive high-throughput intact protein profiling. The approach employs a high resolution reversed phase (RP) LC separation coupled with LC eluent fraction collection and concurrent on-line MS with a high field (12 Tesla) Fourier-transform ion cyclotron resonance (FTICR) mass spectrometer. Protein elusion profiles and tentative modified protein identification are made using detected intact protein mass in conjunction with bottom-up protein identifications from the enzymatic digestion and analysis of corresponding LC fractions. Specific proteins of biological interest are incorporated into a target ion list for subsequent off-line gas-phase fragmentation that uses an aliquot of the original collected LC fraction, an aliquot of which was also used for bottom-up analysis.

  14. Bottom-Up Molecular Tunneling Junctions Formed by Self-Assembly

    NARCIS (Netherlands)

    Zhang, Yanxi; Zhao, Zhiyuan; Fracasso, Davide; Chiechi, Ryan C

    2014-01-01

    This Minireview focuses on bottom-up molecular tunneling junctions - a fundamental component of molecular electronics - that are formed by self-assembly. These junctions are part of devices that, in part, fabricate themselves, and therefore, are particularly dependent on the chemistry of the molecul

  15. Ways toward a European Vocational Education and Training Space: A "Bottom-Up" Approach

    Science.gov (United States)

    Blings, Jessica; Spottl, Georg

    2008-01-01

    Purpose: This paper seeks to concentrate on bottom-up approaches in order to promote a European vocational education and training (VET) concept. The overall aim of this article is to demonstrate that sophisticated approaches still have a chance of becoming common practice in European countries. Design/methodology/approach: The centre of the…

  16. Top-Down or Bottom-Up? Coping with Territorial Fragmentation in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Illner, Michal

    Houndmills, Basingstoke: PALGRAVE MACMILLAN, 2010 - (Baldersheim, H.; Lawrence, E.), s. 214-233 ISBN 978-0-230-23333-1 R&D Projects: GA MŠk 2D06006 Institutional research plan: CEZ:AV0Z70280505 Keywords : Czech Republic * municipalities * bottom-up consolidation Subject RIV: AO - Sociology, Demography

  17. Conciliating TOP-DOWN and BOTTOM-UP approaches in Websites quality evaluation

    OpenAIRE

    Biscoglio, Isabella; Trentanni, Gianluca

    2007-01-01

    Websites are the most important media of our times. Consequently a method which allows us to better evaluate websites quality is priceless. In this paper two websites evaluation opposite approaches, namely "bottom-up" and "top-down", are compared and an hypothesis of their meeting in the middle is shown.

  18. Nanoelectronics: the Hall Effect and Measurement of Electrochemical Potentials by «Bottom-Up» Approach

    OpenAIRE

    Yu.A. Kruglyak; P.A. Kondratenko; Yu.М. Lopatkin

    2015-01-01

    Classical and quantum Hall effects, measurement of electrochemical potentials, the Landauer formulas and Buttiker formula, measurement of Hall potential, an account of magnetic field in the NEGF method, quantum Hall effect, Landau method, and edge states in graphene are discussed in the frame of the «bottom-up» approach of modern nanoelectronics.

  19. Oriented bottom-up growth of armchair graphene nanoribbons on germanium

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, Michael Scott; Jacobberger, Robert Michael

    2016-03-15

    Graphene nanoribbon arrays, methods of growing graphene nanoribbon arrays and electronic and photonic devices incorporating the graphene nanoribbon arrays are provided. The graphene nanoribbons in the arrays are formed using a scalable, bottom-up, chemical vapor deposition (CVD) technique in which the (001) facet of the germanium is used to orient the graphene nanoribbon crystals along the [110] directions of the germanium.

  20. Nanoelectronics: the Hall Effect and Measurement of Electrochemical Potentials by «Bottom-Up» Approach

    Directory of Open Access Journals (Sweden)

    Yu.A. Kruglyak

    2015-06-01

    Full Text Available Classical and quantum Hall effects, measurement of electrochemical potentials, the Landauer formulas and Buttiker formula, measurement of Hall potential, an account of magnetic field in the NEGF method, quantum Hall effect, Landau method, and edge states in graphene are discussed in the frame of the «bottom-up» approach of modern nanoelectronics.

  1. How Adolescents Comprehend Unfamiliar Proverbs: The Role of Top-Down and Bottom-Up Processes.

    Science.gov (United States)

    Nippold, Marilyn A.; Allen, Melissa M.; Kirsch, Dixon I.

    2000-01-01

    Relationships between word knowledge and proverb comprehension was examined in 150 typically achieving adolescents (ages 12, 15, and 18). Word knowledge was associated with proverb comprehension in all groups, particularly in the case of abstract proverbs. Results support a model of proverb comprehension in adolescents that includes bottom-up in…

  2. Co-financing of bottom-up approaches towards Broadband Infrastructure Development

    DEFF Research Database (Denmark)

    Williams, Idongesit

    2016-01-01

    networks –leading to the demise of some of these initiatives. This paper proposes co-financing of these networks as a means of sustaining the bottom-up Broadband network. The argument of this paper is anchored on two of developing country cases. One in India and the other in Ghana. One survived with...

  3. A photofunctional bottom-up bis(dipyrrinato)zinc(II) complex nanosheet

    Science.gov (United States)

    Sakamoto, Ryota; Hoshiko, Ken; Liu, Qian; Yagi, Toshiki; Nagayama, Tatsuhiro; Kusaka, Shinpei; Tsuchiya, Mizuho; Kitagawa, Yasutaka; Wong, Wai-Yeung; Nishihara, Hiroshi

    2015-04-01

    Two-dimensional polymeric nanosheets have recently gained much attention, particularly top-down nanosheets such as graphene and metal chalcogenides originating from bulk-layered mother materials. Although molecule-based bottom-up nanosheets manufactured directly from molecular components can exhibit greater structural diversity than top-down nanosheets, the bottom-up nanosheets reported thus far lack useful functionalities. Here we show the design and synthesis of a bottom-up nanosheet featuring a photoactive bis(dipyrrinato)zinc(II) complex motif. A liquid/liquid interfacial synthesis between a three-way dipyrrin ligand and zinc(II) ions results in a multi-layer nanosheet, whereas an air/liquid interfacial reaction produces a single-layer or few-layer nanosheet with domain sizes of >10 μm on one side. The bis(dipyrrinato)zinc(II) metal complex nanosheet is easy to deposit on various substrates using the Langmuir-Schäfer process. The nanosheet deposited on a transparent SnO2 electrode functions as a photoanode in a photoelectric conversion system, and is thus the first photofunctional bottom-up nanosheet.

  4. Oral bioavailability and pharmacodynamic activity of hesperetin nanocrystals generated using a novel bottom-up technology

    DEFF Research Database (Denmark)

    Shete, Ganesh; Pawar, Yogesh B; Thanki, Kaushik; Jain, Sanyog; Bansal, Arvind Kumar

    2015-01-01

    In the present study, nanocrystalline solid dispersion (NSD) was developed to enhance the release rate and oral bioavailability of hesperetin (HRN). NSD of HRN was prepared using a novel bottom-up technology platform. It is a spray drying based technology to generate solid particles, containing...

  5. Integration of top-down and bottom-up information for audio organization and retrieval

    DEFF Research Database (Denmark)

    Jensen, Bjørn Sand

    sources based on latent Dirichlet allocation (LDA). The model is used to integrate bottom-up features (reflecting timbre, loudness, tempo and chroma), meta-data aspects (lyrics) and top-down aspects, namely user generated open vocabulary tags. The model and representation is evaluated on the auxiliary...

  6. Bottom-up model of self-organized criticality on networks.

    Science.gov (United States)

    Noël, Pierre-André; Brummitt, Charles D; D'Souza, Raissa M

    2014-01-01

    The Bak-Tang-Wiesenfeld (BTW) sandpile process is an archetypal, stylized model of complex systems with a critical point as an attractor of their dynamics. This phenomenon, called self-organized criticality, appears to occur ubiquitously in both nature and technology. Initially introduced on the two-dimensional lattice, the BTW process has been studied on network structures with great analytical successes in the estimation of macroscopic quantities, such as the exponents of asymptotically power-law distributions. In this article, we take a microscopic perspective and study the inner workings of the process through both numerical and rigorous analysis. Our simulations reveal fundamental flaws in the assumptions of past phenomenological models, the same models that allowed accurate macroscopic predictions; we mathematically justify why universality may explain these past successes. Next, starting from scratch, we obtain microscopic understanding that enables mechanistic models; such models can, for example, distinguish a cascade's area from its size. In the special case of a 3-regular network, we use self-consistency arguments to obtain a zero-parameter mechanistic (bottom-up) approximation that reproduces nontrivial correlations observed in simulations and that allows the study of the BTW process on networks in regimes otherwise prohibitively costly to investigate. We then generalize some of these results to configuration model networks and explain how one could continue the generalization. The numerous tools and methods presented herein are known to enable studying the effects of controlling the BTW process and other self-organizing systems. More broadly, our use of multitype branching processes to capture information bouncing back and forth in a network could inspire analogous models of systems in which consequences spread in a bidirectional fashion. PMID:24580281

  7. Bottom-up impact on the cecidomyiid leaf galler and its parasitism in a tropical rainforest.

    Science.gov (United States)

    Malinga, Geoffrey M; Valtonen, Anu; Nyeko, Philip; Vesterinen, Eero J; Roininen, Heikki

    2014-10-01

    The relative importance of host-plant resources, natural enemies or their interactions in controlling the population of galling insects and their parasitism is poorly known for tropical gallers. In this study, we assessed the impacts of plant quality and density of host trees in regulating the densities of a galler species, the cecidomyiid leaf galler (Cecidomyiini sp. 1EJV) and its parasitoids and inquilines on Neoboutonia macrocalyx trees in Uganda. We manipulated the nutritional quality (or vigour) and the resource concentration with four levels each of fertilization and the group size of host tree. We then recorded the effects of these treatments on the growth rate and total leaf area of host plants, the density of gallers and their mortality by parasitoids and inquilines. Higher levels of fertilization and host density resulted in significantly higher total leaf area than did ambient nutrient levels, and lowest tree densities, respectively. Fertilization also caused significant change in the growth rate of leaf area. Both higher fertilization and host density caused higher density of gallers. Total leaf area was positively associated with galler density, but within galled replicates, the galled leaves were larger than the ungalled leaves. Although highest levels of fertilization and density of host trees caused significant change in the densities of parasitoids, the rate of parasitism did not change. However, tree-density manipulations increased the rate of inquilinism, but on a very low level. Our results demonstrate a trophic cascade in the tropical galler and its parasitoids as a response to bottom-up effects. PMID:25124946

  8. Top-down and bottom-up processes in grassland and forested streams.

    Science.gov (United States)

    Nyström, Per; McIntosh, Angus R; Winterbourn, Michael J

    2003-08-01

    The influence of predatory fish on the structure of stream food webs may be altered by the presence of forest canopy cover, and consequent differences in allochthonous inputs and primary production. Eight sites containing introduced brown trout ( Salmo trutta) and eight sites that did not were sampled in the Cass region, South Island, New Zealand. For each predator category, half the sites were located in southern beech (Nothofagus) forest patches (range of canopy cover, 65-90%) and the other half were in tussock grassland. Food resources used by two dominant herbivores-detritivores were assessed using stable isotopes. (13)C/(12)C ratios were obtained for coarse particulate organic matter (CPOM), fine particulate organic matter (FPOM), algal dominated biofilm from rocks, and larvae of Deleatidium (Ephemeroptera) and Olinga (Trichoptera). Total abundance and biomass of macroinvertebrates did not differ between streams with and without trout, but were significantly higher at grassland sites than forested sites. However, taxon richness and species composition differed substantially between trout and no-trout sites, irrespective of whether streams were located in forest or not. Trout streams typically contained more taxa, had low biomass of predatory invertebrates and large shredders, but a high proportion of consumers with cases or shells. The standing stock of CPOM was higher at forested sites, but there was less FPOM and more algae at sites with trout, regardless of the presence or absence of forest cover. The stable carbon isotope range for biofilm on rocks was broad and encompassed the narrow CPOM and FPOM ranges. At trout sites, carbon isotope ratios of Deleatidium, the most abundant invertebrate primary consumer, were closely related to biofilm values, but no relationship was found at no-trout sites where algal biomass was much lower. These results support a role for both bottom-up and top-down processes in controlling the structure of the stream communities

  9. Orchestrated structure evolution: accelerating direct-write nanomanufacturing by combining top-down patterning with bottom-up growth

    International Nuclear Information System (INIS)

    Direct-write nanomanufacturing with scanning beams and probes is flexible and can produce high quality products, but it is normally slow and expensive to raster point-by-point over a pattern. We demonstrate the use of an accelerated direct-write nanomanufacturing method called 'orchestrated structure evolution' (OSE), where a direct-write tool patterns a small number of growth 'seeds' that subsequently grow into the final thin film pattern. Through control of seed size and spacing, it is possible to vary the ratio of 'top-down' to 'bottom-up' character of the patterning processes, ranging from conventional top-down raster patterning to nearly pure bottom-up space-filling via seed growth. Electron beam lithography (EBL) and copper electrodeposition were used to demonstrate trade-offs between process time and product quality over nano- to microlength scales. OSE can reduce process times for high-cost EBL patterning by orders of magnitude, at the expense of longer (but inexpensive) copper electrodeposition processing times. We quantify the degradation of pattern quality that accompanies fast OSE patterning by measuring deviations from the desired patterned area and perimeter. We also show that the density of OSE-induced grain boundaries depends upon the seed separation and size. As the seed size is reduced, the uniformity of an OSE film becomes more dependent on details of seed nucleation processes than normally seen for conventionally patterned films.

  10. The life cycle of bottom-up ideas : case studies of the companies where the simulation game method was applied

    OpenAIRE

    Forssén, Minna

    2002-01-01

    The main aim of this thesis is to study the life cycle of the incremental "bottom-up" ideas, which concern process and organizational matters. According to earlier studies, bottom-up ideas are not always successfully used and managed and as well there exists need for more study on organizational and process innovations. It is therefore useful to study this phenomenon more and gain more information about how organizations manage the development and implementation of these bottom-up ideas. ...

  11. Hybrid Top-Down/Bottom-Up Strategy Using Superwettability for the Fabrication of Patterned Colloidal Assembly.

    Science.gov (United States)

    Wang, Yuezhong; Wei, Cong; Cong, Hailin; Yang, Qiang; Wu, Yuchen; Su, Bin; Zhao, Yongsheng; Wang, Jingxia; Jiang, Lei

    2016-02-24

    Superwettability of substrates has had a profound influence on the production of novel and advanced colloidal assemblies in recent decades owing to its effect on the spreading area, evaporation rate, and the resultant assembly structure. In this paper, we investigated in detail the influence of the superwettability of a transfer/template substrate on the colloidal assembly from a hybrid top-down/bottom-up strategy. By taking advantage of a superhydrophilic flat transfer substrate and a superhydrophobic groove-structured silicon template, the patterned colloidal microsphere assembly was formed including linear and mesh-, cyclic-, and multistopband assembly arrays of microspheres, and the optic-waveguide of a circular colloidal structure was demonstrated. We believed this liquid top-down/bottom-up strategy would open an efficient avenue for assembling/integrating microspheres building blocks into device applications in a low-cost manner. PMID:26824430

  12. Co-financing of bottom-up approaches towards Broadband Infrastructure Development:

    DEFF Research Database (Denmark)

    Williams, Idongesit

    2016-01-01

    Bottom – up Broadband infrastructure development facilitated by the civil societies and social enterprises are on the increase. However, the problem plaguing the development of these bottom-up approaches in developing countries is the financial capacity to expand their small networks into larger...... networks –leading to the demise of some of these initiatives. This paper proposes co-financing of these networks as a means of sustaining the bottom-up Broadband network. The argument of this paper is anchored on two of developing country cases. One in India and the other in Ghana. One survived with...... financial injection and the other did not due to low revenue. This paper, based on these cases, proposes the utilization and the reintroduction of Universal Service funds in developing countries to aid these small networks. This is a qualitative study, the Grounded Theory approach was used adopted gather...

  13. A balance of bottom-up and top-down in linking climate policies

    Science.gov (United States)

    Green, Jessica F.; Sterner, Thomas; Wagner, Gernot

    2014-12-01

    Top-down climate negotiations embodied by the Kyoto Protocol have all but stalled, chiefly because of disagreements over targets and objections to financial transfers. To avoid those problems, many have shifted their focus to linkage of bottom-up climate policies such as regional carbon markets. This approach is appealing, but we identify four obstacles to successful linkage: different levels of ambition; competing domestic policy objectives; objections to financial transfers; and the difficulty of close regulatory coordination. Even with a more decentralized approach, overcoming the 'global warming gridlock' of the intergovernmental negotiations will require close international coordination. We demonstrate how a balance of bottom-up and top-down elements can create a path toward an effective global climate architecture.

  14. Transition UGent: a bottom-up initiative towards a more sustainable university

    OpenAIRE

    Block, Thomas; Van de Velde, Riet

    2016-01-01

    The vibrant think-tank ‘Transition UGent’ engaged over 250 academics, students and people from the university management in suggesting objectives and actions for the Sustainability Policy of Ghent University (Belgium). Founded in 2012, this bottom-up initiative succeeded to place sustainability high on the policy agenda of our university. Through discussions within 9 working groups and using the transition management method, Transition UGent developed system analyses, sustainability visions a...

  15. Integrating top down policies and bottom up practices in Urban and Periurban Agriculture: an Italian dilemma

    OpenAIRE

    Cinà, Giuseppe; Di Iacovo, Francesco

    2015-01-01

    The paper deals with some relevant and contradictory aspects of urban and peri-urban agriculture in Italy: the traditional exclusion of agricultural areas from the goals of territorial planning; the separation between top-down policies and bottom-up practices; the lack of agricultural policies at local scale. In the first part the paper summarises the weak relation between urban planning and agriculture, showing how in Italy this gap has been only partially overcome by new laws and plans. Mor...

  16. Reforming the taxation of multijurisdictional enterprises in Europe: coopetition in a bottom-up federation

    OpenAIRE

    Gérard, Marcel

    2006-01-01

    This paper investigates replacing separate taxation by consolidation and formulary apportionment in a Bottom-up Federation, when a multijurisdictional firm is mobile in various respects. The reform is decided cooperatively by all the jurisdictions or by some of them, while tax rates remain within the competence of each jurisdiction. The paper sets forth the conditions for the reform to be social welfare enhancing, while not increasing tax competition. Among them, the formula should emphasize ...

  17. Bottom-up effects of soil quality on a coffee arthropod interaction web

    OpenAIRE

    Gonthier, DJ; Dominguez, GM; Witter, JD; Spongberg, AL; Philpott, SM

    2013-01-01

    Nutrient availability and soil quality influence herbivores through changes in plant traits and can have cascading effects on herbivore interactions. In complex systems, with many positive and negative interactions, the consequences of these bottom-up effects are still not well established. We carried out a set of studies to determine the impact of soil quality (organic compost amendments) on a hemipteran herbivore (Coccus viridis), two ant mutualists, predators, pathogens, parasitoids of C. ...

  18. Self-assembled nanostructured resistive switching memory devices fabricated by templated bottom-up growth

    OpenAIRE

    Ji-Min Song; Jang-Sik Lee

    2016-01-01

    Metal-oxide-based resistive switching memory device has been studied intensively due to its potential to satisfy the requirements of next-generation memory devices. Active research has been done on the materials and device structures of resistive switching memory devices that meet the requirements of high density, fast switching speed, and reliable data storage. In this study, resistive switching memory devices were fabricated with nano-template-assisted bottom up growth. The electrochemical ...

  19. Public participation GIS to support a bottom-up approach in forest landscape planning

    OpenAIRE

    Paletto A; Lora C; Frattegiani M; De Meo I; Ferretti F

    2013-01-01

    Forest landscape planning analyses all forest aspects (economic, ecological and social) and defines long-term forest management guidelines. Various actors are involved in landscape planning; therefore the analysis needs to take into account goals and targets of the different stakeholders. The participatory process can strongly support the development of a bottom-up forest plan definition when stakeholders are involved throughout the decision-making process. In this way, management guidelines ...

  20. Environmental Sustainability and Regulation: To-Down Versus Bottom-Up Regulation

    OpenAIRE

    Mariam, Yohannes

    2001-01-01

    Environmental regulation can be broadly divided into those that follow the top-down and bottom-up approaches. The two approaches have similar objective with respect to environmental protection and sustainability. However, the success with which each approach achieves goals of environmental protection and sustainability may vary. Moreover, the costs and benefits of each approach differ. The present study will explore the implication of environmental regulation to sustainability, costs associat...

  1. New bottom-up algorithm for assembly plan generation : opportunities for micro-factory design.

    OpenAIRE

    Perrard, Christophe; Lutz, Philippe; Salgueiro, Paulo

    2007-01-01

    This paper discusses a new approach dedicated to assembly plan generation, called "bottom-up algorithm". It is compared to the traditional "top-down approach", usually used to perform this stage of the design process of the assembly systems for "macro-products". We explore why this new algorithm is better adapted for designing a microassembly system. The case of watch assembly plans generation is described through the both approaches and the obtained results are compared.

  2. Bottom-Up Dependent Gating of Frontal Signals in Early Visual Cortex

    OpenAIRE

    Ekstrom, L. B.; P. R. Roelfsema; Arsenault, J.T.; Bonmassar, G.; Vanduffel, W.

    2008-01-01

    The frontal eye field (FEF) is one of several cortical regions thought to modulate sensory inputs. Moreover, several hypotheses suggest that the FEF can only modulate early visual areas in the presence of a visual stimulus. To test for bottom-up gating of frontal signals, we microstimulated subregions in the FEF of two monkeys and measured the effects throughout the brain with functional magnetic resonance imaging. The activity of higher-order visual areas was strongly modulated by FEF stimul...

  3. Combining shape and color: a bottom-up approach to evaluate object similarities

    OpenAIRE

    PASCUCCI, ALESSIO

    2011-01-01

    The objective of the present work is to develop a bottom-up approach to estimate the similarity between two unknown objects. Given a set of digital images, we want to identify the main objects and to determine whether they are similar or not. In the last decades many object recognition and classification strategies, driven by higher-level activities, have been successfully developed. The peculiarity of this work, instead, is the attempt to work without any training phase nor a priori knowledg...

  4. The Application of Bottom-up and Top-down Processing in L2 Listening Comprehension

    Institute of Scientific and Technical Information of China (English)

    温颖茜

    2008-01-01

    Listening comprehension is one of the four basic skills for language learning and is also one of the most difficult tasks L2 learners ever experienced.L2 listening comprehemion is a cognitvive process,in which listeners use both bottom-up andtop-downprocessing to comprehend the auraltext.Thepaper focmes on the applicationof the two approaches in L2 lis-tening comprehemiom

  5. A VHDL-AMS Modeling Methodology for Top-Down/Bottom-Up Design of RF Systems

    OpenAIRE

    Maehne, Torsten; Vachoux, Alain; Giroud, Frédéric; Contaldo, Matteo

    2009-01-01

    This paper presents a modelling methodology for the top-down/bottom-up design of RF systems based on systematic use of VHDL-AMS models. The model interfaces are parameterizable and pin-accurate. The designer can choose to parameterize the models using performance specifications or device parameters back-annotated from the transistor-level implementation. The abstraction level used for the description of the respective analog/digital component behavior has been chosen to achieve a good t...

  6. A computational study of liposome logic: towards cellular computing from the bottom up

    OpenAIRE

    Smaldon, James; Romero-Campero, Francisco J.; Fernández Trillo, Francisco; Gheorghe, Marian; Alexander, Cameron; Krasnogor, Natalio

    2010-01-01

    In this paper we propose a new bottom-up approach to cellular computing, in which computational chemical processes are encapsulated within liposomes. This “liposome logic” approach (also called vesicle computing) makes use of supra-molecular chemistry constructs, e.g. protocells, chells, etc. as minimal cellular platforms to which logical functionality can be added. Modeling and simulations feature prominently in “top-down” synthetic biology, particularly in the specification, design and impl...

  7. Can bottom-up ocean CO2 fluxes be reconciled with atmospheric 13C observations?

    OpenAIRE

    Alden, Caroline B.; Miller, John B.; White, James W.C.

    2011-01-01

    The rare stable carbon isotope, 13C, has been used previously to partition CO2 fluxes into land and ocean components. Net ocean and land fluxes impose distinctive and predictable fractionation patterns upon the stable isotope ratio, making it an excellent tool for distinguishing between them. Historically, isotope constrained inverse methods for calculating CO2 surface fluxes—the ‘double deconvolution’—have disagreed with bottom-up ocean flux estimates. In this study, we use the double deconv...

  8. Bottom-Up Cost Analysis of a High Concentration PV Module

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey A. W.; Woodhouse, Michael; Lee, Hohyun; Smestad, Greg P.

    2016-03-31

    We present a bottom-up model of III-V multi-junction cells, as well as a high concentration PV (HCPV) module. We calculate $0.59/W(DC) manufacturing costs for our model HCPV module design with today's capabilities, and find that reducing cell costs and increasing module efficiency offer the most promising paths for future cost reductions. Cell costs could be significantly reduced via substrate reuse and improved manufacturing yields.

  9. Nanomaterial processing using self-assembly-bottom-up chemical and biological approaches

    International Nuclear Information System (INIS)

    Nanotechnology is touted as the next logical sequence in technological evolution. This has led to a substantial surge in research activities pertaining to the development and fundamental understanding of processes and assembly at the nanoscale. Both top-down and bottom-up fabrication approaches may be used to realize a range of well-defined nanostructured materials with desirable physical and chemical attributes. Among these, the bottom-up self-assembly process offers the most realistic solution toward the fabrication of next-generation functional materials and devices. Here, we present a comprehensive review on the physical basis behind self-assembly and the processes reported in recent years to direct the assembly of nanoscale functional blocks into hierarchically ordered structures. This paper emphasizes assembly in the synthetic domain as well in the biological domain, underscoring the importance of biomimetic approaches toward novel materials. In particular, two important classes of directed self-assembly, namely, (i) self-assembly among nanoparticle–polymer systems and (ii) external field-guided assembly are highlighted. The spontaneous self-assembling behavior observed in nature that leads to complex, multifunctional, hierarchical structures within biological systems is also discussed in this review. Recent research undertaken to synthesize hierarchically assembled functional materials have underscored the need as well as the benefits harvested in synergistically combining top-down fabrication methods with bottom-up self-assembly. (review article)

  10. Plasma-surface interactions for top-down and bottom-up nanofabrication

    Science.gov (United States)

    Ono, Kouichi

    2015-09-01

    Plasma processing is now widely employed for the fabrication of nanostructures in diverse fields of micro/nanoelectronic, optoelectronic, energy conversion, and sensing devices. The top-down plasma processes are indispensable in today's microelectronics industry, relying on the use of primarily anisotropic plasma etching following the lithography to define mask patterns; in some cases, self-assembled masks are served for the subsequent etching. The bottom-up ones are often employed to synthesize nanostructures such as nanotubes and nanowires, relying on the use of plasma enhanced chemical vapor deposition and plasma sputtering on self-assembled as well as lithographically formed patterns of metal catalysts. Moreover, the mask-less top-down approaches have recently been demonstrated to form nanopillars and periodic nanoripples, and the catalyst-free bottom-up approaches have been demonstrated to form nanowires. This talk is concerned with the current understanding and future prospects for plasma-surface interactions responsible for these top-down and bottom-up plasma nanofabrication processes, with attention placed on the fabrication of nanoscale fins and gates and also nanowires of silicon. On nanometer scale, ions and neutrals incident on surfaces are few in number during processing; thus, the nanoscale plasma-surface interactions concerned are stochastic, owing to the temporal as well as spatial uniformity of the incident flux and angle of them on surfaces being processed at nanoscale.

  11. Top-down and bottom-up modulation in processing bimodal face/voice stimuli

    Directory of Open Access Journals (Sweden)

    VanRullen Rufin

    2010-03-01

    Full Text Available Abstract Background Processing of multimodal information is a critical capacity of the human brain, with classic studies showing bimodal stimulation either facilitating or interfering in perceptual processing. Comparing activity to congruent and incongruent bimodal stimuli can reveal sensory dominance in particular cognitive tasks. Results We investigated audiovisual interactions driven by stimulus properties (bottom-up influences or by task (top-down influences on congruent and incongruent simultaneously presented faces and voices while ERPs were recorded. Subjects performed gender categorisation, directing attention either to faces or to voices and also judged whether the face/voice stimuli were congruent in terms of gender. Behaviourally, the unattended modality affected processing in the attended modality: the disruption was greater for attended voices. ERPs revealed top-down modulations of early brain processing (30-100 ms over unisensory cortices. No effects were found on N170 or VPP, but from 180-230 ms larger right frontal activity was seen for incongruent than congruent stimuli. Conclusions Our data demonstrates that in a gender categorisation task the processing of faces dominate over the processing of voices. Brain activity showed different modulation by top-down and bottom-up information. Top-down influences modulated early brain activity whereas bottom-up interactions occurred relatively late.

  12. Top-down or bottom-up modelling. An application to CO2 abatement

    International Nuclear Information System (INIS)

    In four articles a comparison is made of bottom-up, or engineers'' models, and top-down models, which comprise macro-econometric models, computable general equilibrium models and also models in the system dynamics tradition. In the first article the history of economic modelling is outlined. In the second article the multi-sector macro-economic Computable General Equilibrium model for the Netherlands is described. It can be used to study the long-term effects of fiscal policy measures on economic and environmental indicators, in particular the effects on the level of CO2-emissions. The aim of article 3 is to describe the structure of the electricity supply industry in the UK and how it can be represented in a bottom-up sub-model within a more general E3 sectoral model of the UK economy. The objective of the last paper (4) is mainly a methodological discussion about integrating top-down and bottom-up models which can be used to assess CO2 abatement policies impacts on economic activity

  13. Ecology of phasmids (phasmatodea) in a moist neotropical forest: a study on life history, host-range and bottom-up versus top-down regulation

    OpenAIRE

    Berger, Jürgen

    2004-01-01

    Herbivory is discussed as a key agent in maintaining dynamics and stability of tropical forested ecosystems. Accordingly increasing attention has been paid to the factors that structure tropical herbivore communities. The aim of this study was (1) to describe diversity, density, distribution and host range of the phasmid community (Phasmatodea) of a moist neotropical forest in Panamá, and (2) to experimentally assess bottom-up and top-down factors that may regulate populations of the phasmid ...

  14. Atomic layer deposition-Sequential self-limiting surface reactions for advanced catalyst "bottom-up" synthesis

    Science.gov (United States)

    Lu, Junling; Elam, Jeffrey W.; Stair, Peter C.

    2016-06-01

    Catalyst synthesis with precise control over the structure of catalytic active sites at the atomic level is of essential importance for the scientific understanding of reaction mechanisms and for rational design of advanced catalysts with high performance. Such precise control is achievable using atomic layer deposition (ALD). ALD is similar to chemical vapor deposition (CVD), except that the deposition is split into a sequence of two self-limiting surface reactions between gaseous precursor molecules and a substrate. The unique self-limiting feature of ALD allows conformal deposition of catalytic materials on a high surface area catalyst support at the atomic level. The deposited catalytic materials can be precisely constructed on the support by varying the number and type of ALD cycles. As an alternative to the wet-chemistry based conventional methods, ALD provides a cycle-by-cycle "bottom-up" approach for nanostructuring supported catalysts with near atomic precision. In this review, we summarize recent attempts to synthesize supported catalysts with ALD. Nucleation and growth of metals by ALD on oxides and carbon materials for precise synthesis of supported monometallic catalyst are reviewed. The capability of achieving precise control over the particle size of monometallic nanoparticles by ALD is emphasized. The resulting metal catalysts with high dispersions and uniformity often show comparable or remarkably higher activity than those prepared by conventional methods. For supported bimetallic catalyst synthesis, we summarize the strategies for controlling the deposition of the secondary metal selectively on the primary metal nanoparticle but not on the support to exclude monometallic formation. As a review of the surface chemistry and growth behavior of metal ALD on metal surfaces, we demonstrate the ways to precisely tune size, composition and structure of bimetallic metal nanoparticles. The cycle-by-cycle "bottom up" construction of bimetallic (or multiple

  15. Construction of membrane-bound artificial cells using microfluidics: a new frontier in bottom-up synthetic biology

    Science.gov (United States)

    Elani, Yuval

    2016-01-01

    The quest to construct artificial cells from the bottom-up using simple building blocks has received much attention over recent decades and is one of the grand challenges in synthetic biology. Cell mimics that are encapsulated by lipid membranes are a particularly powerful class of artificial cells due to their biocompatibility and the ability to reconstitute biological machinery within them. One of the key obstacles in the field centres on the following: how can membrane-based artificial cells be generated in a controlled way and in high-throughput? In particular, how can they be constructed to have precisely defined parameters including size, biomolecular composition and spatial organization? Microfluidic generation strategies have proved instrumental in addressing these questions. This article will outline some of the major principles underpinning membrane-based artificial cells and their construction using microfluidics, and will detail some recent landmarks that have been achieved. PMID:27284034

  16. Zooplankton and forage fish species off Peru: Large-scale bottom-up forcing and local-scale depletion

    Science.gov (United States)

    Ayón, Patricia; Swartzman, Gordon; Bertrand, Arnaud; Gutiérrez, Mariano; Bertrand, Sophie

    2008-10-01

    The Humboldt Current System, like all upwelling systems, has dramatic quantities of plankton-feeding fish, which suggested that their population dynamics may ‘drive’ or ‘control’ ecosystem dynamics. With this in mind we analysed the relationship between forage fish populations and their main prey, zooplankton populations. Our study combined a zooplankton sampling program (1961-2005) with simultaneous acoustic observations on fish from 40 pelagic surveys (1983-2005) conducted by the Peruvian Marine Research Institute (IMARPE) and landing statistics for anchoveta ( Engraulis ringens) and sardine ( Sardinops sagax) along the Peruvian coast from 1961 to 2005. The multi-year trend of anchoveta population abundance varied consistently with zooplankton biovolume trend, suggesting bottom-up control on anchovy at the population scale (since oceanographic conditions and phytoplankton production support the changes in zooplankton abundance). For a finer-scale analysis (km) we statistically modelled zooplankton biovolume as a function of geographical (latitude and distance from the 200-m isobath), environmental (sea surface temperature), temporal (year, month and time-of-day) and biological (acoustic anchovy and sardine biomass within 5 km of each zooplankton sample) covariates over all survey using both classification and regression trees (CART) and generalized additive models (GAM). CART showed local anchoveta density to have the strongest effect on zooplankton biovolume, with significantly reduced levels of biovolume for higher neighbourhood anchoveta biomass. Additionally, zooplankton biovolume was higher offshore than on the shelf. GAM results corroborated the CART findings, also showing a clear diel effect on zooplankton biovolume, probably due to diel migration or daytime net avoidance. Apparently, the observed multi-year population scale bottom-up control is not inconsistent with local depletion of zooplankton when anchoveta are locally abundant, since the

  17. Visual anticipation biases conscious perception but not bottom-up visual processing

    Directory of Open Access Journals (Sweden)

    Paul F.M.J. Verschure

    2015-01-01

    Full Text Available Theories of consciousness can be grouped with respect to their stance on embodiment, sensori-motor contingencies, prediction and integration. In this list prediction plays a key role and it is not clear which aspects of prediction are most prominent in the conscious scene. An evolving view on the brain is that it can be seen as a prediction machine that optimizes its ability to predict states of the world and the self through the top-down propagation of predictions and the bottom-up presentation of prediction errors. There are competing views though on whether prediction or prediction errors dominate the conscious scene. Yet, due to the lack of efficient indirect measures, the dynamic effects of prediction on perception, decision making and consciousness have been difficult to assess and to model. We propose a novel mathematical framework and psychophysical paradigm that allows us to assess both the hierarchical structuring of perceptual consciousness, its content and the impact of predictions and / or errors on the conscious scene. Using a displacement detection task combined with reverse correlation we reveal signatures of the usage of prediction at three different levels of perception: bottom-up early saccades, top-down driven late saccades and conscious decisions. Our results suggest that the brain employs multiple parallel mechanisms at different levels of information processing to restrict the sensory field using predictions. We observe that cognitive load has a quantifiable effect on this dissociation of the bottom-up sensory and top-down predictive processes. We propose a probabilistic data association model from dynamical systems theory to model this predictive bias in different information processing levels.

  18. A computational study of liposome logic: towards cellular computing from the bottom up.

    Science.gov (United States)

    Smaldon, James; Romero-Campero, Francisco J; Fernández Trillo, Francisco; Gheorghe, Marian; Alexander, Cameron; Krasnogor, Natalio

    2010-09-01

    In this paper we propose a new bottom-up approach to cellular computing, in which computational chemical processes are encapsulated within liposomes. This "liposome logic" approach (also called vesicle computing) makes use of supra-molecular chemistry constructs, e.g. protocells, chells, etc. as minimal cellular platforms to which logical functionality can be added. Modeling and simulations feature prominently in "top-down" synthetic biology, particularly in the specification, design and implementation of logic circuits through bacterial genome reengineering. The second contribution in this paper is the demonstration of a novel set of tools for the specification, modelling and analysis of "bottom-up" liposome logic. In particular, simulation and modelling techniques are used to analyse some example liposome logic designs, ranging from relatively simple NOT gates and NAND gates to SR-Latches, D Flip-Flops all the way to 3 bit ripple counters. The approach we propose consists of specifying, by means of P systems, gene regulatory network-like systems operating inside proto-membranes. This P systems specification can be automatically translated and executed through a multiscaled pipeline composed of dissipative particle dynamics (DPD) simulator and Gillespie's stochastic simulation algorithm (SSA). Finally, model selection and analysis can be performed through a model checking phase. This is the first paper we are aware of that brings to bear formal specifications, DPD, SSA and model checking to the problem of modeling target computational functionality in protocells. Potential chemical routes for the laboratory implementation of these simulations are also discussed thus for the first time suggesting a potentially realistic physiochemical implementation for membrane computing from the bottom-up. PMID:21886681

  19. Neural activities in V1 create the bottom-up saliency map of natural scenes.

    Science.gov (United States)

    Chen, Cheng; Zhang, Xilin; Wang, Yizhou; Zhou, Tiangang; Fang, Fang

    2016-06-01

    A saliency map is the bottom-up contribution to the deployment of exogenous attention. It, as well as its underlying neural mechanism, is hard to identify because of the influence of top-down signals. A recent study showed that neural activities in V1 could create a bottom-up saliency map (Zhang et al. in Neuron 73(1):183-192, 2012). In this paper, we tested whether their conclusion can generalize to complex natural scenes. In order to avoid top-down influences, each image was presented with a low contrast for only 50 ms and was followed by a high contrast mask, which rendered the whole image invisible to participants (confirmed by a forced-choice test). The Posner cueing paradigm was adopted to measure the spatial cueing effect (i.e., saliency) by an orientation discrimination task. A positive cueing effect was found, and the magnitude of the cueing effect was consistent with the saliency prediction of a computational saliency model. In a following fMRI experiment, we used the same masked natural scenes as stimuli and measured BOLD signals responding to the predicted salient region (relative to the background). We found that the BOLD signal in V1, but not in other cortical areas, could well predict the cueing effect. These results suggest that the bottom-up saliency map of natural scenes could be created in V1, providing further evidence for the V1 saliency theory (Li in Trends Cogn Sci 6(1):9-16, 2002). PMID:26879771

  20. Coupled multi-physics simulation frameworks for reactor simulation: A bottom-up approach

    International Nuclear Information System (INIS)

    A 'bottom-up' approach to multi-physics frameworks is described, where first common interfaces to simulation data are developed, then existing physics modules are adapted to communicate through those interfaces. Physics modules read and write data through those common interfaces, which also provide access to common simulation services like parallel IO, mesh partitioning, etc.. Multi-physics codes are assembled as a combination of physics modules, services, interface implementations, and driver code which coordinates calling these various pieces. Examples of various physics modules and services connected to this framework are given. (author)

  1. Unsupervised tattoo segmentation combining bottom-up and top-down cues

    Science.gov (United States)

    Allen, Josef D.; Zhao, Nan; Yuan, Jiangbo; Liu, Xiuwen

    2011-06-01

    Tattoo segmentation is challenging due to the complexity and large variance in tattoo structures. We have developed a segmentation algorithm for finding tattoos in an image. Our basic idea is split-merge: split each tattoo image into clusters through a bottom-up process, learn to merge the clusters containing skin and then distinguish tattoo from the other skin via top-down prior in the image itself. Tattoo segmentation with unknown number of clusters is transferred to a figureground segmentation. We have applied our segmentation algorithm on a tattoo dataset and the results have shown that our tattoo segmentation system is efficient and suitable for further tattoo classification and retrieval purpose.

  2. Public engagement as a field of tension between bottom-up and top-down strategies

    DEFF Research Database (Denmark)

    Horsbøl, Anders; Lassen, Inger

    2012-01-01

    In the ongoing debate about climate change, public engagement is given increasing prominence as a possible solution to a general lack of citizen participation in climate change mitigation efforts. Recent years have seen a surge in public engagement initiatives in many countries in the Western world....... These initiatives often have to deal with dilemmas between participatory aspects and other considerations such as planning efficiency, dilemmas that potentially bring about tension between bottom-up and top-down strategies. Literature on climate change issues has addressed the failure of public response...... more knowledge and information about climate change has not significantly changed people’s behaviour towards higher involvement....

  3. Supporting Frequent Updates in R-Trees: A Bottom-Up Approach

    DEFF Research Database (Denmark)

    Lee, Mong Li; Hsu, Wynne; Jensen, Christian Søndergaard;

    2003-01-01

    locality. While the R-tree is the index of choice for multi-dimensional data with low dimensionality, and is thus relevant to these applications, R-tree updates are also relatively inefficient. We present a generalized bottom-up update strategy for R-trees that generalizes existing update techniques and......Advances in hardware-related technologies promise to enable new data management applications that monitor continuous processes. In these applications, enormous amounts of state samples are obtained via sensors and are streamed to a database. Further, updates are very frequent and may exhibit...

  4. Bottom-up approach for the fabrication of spin torque nano-oscillators

    Energy Technology Data Exchange (ETDEWEB)

    Darques, M; De la Torre Medina, J; Abreu Araujo, F; Piraux, L [Institute of Condensed Matter and Nanosciences, Universite catholique de Louvain, Croix du Sud 1, Louvain-la-Neuve (Belgium); Dussaux, A; Khvalkovskiy, A V; Guillemet, R; Bouzehouane, K; Fusil, S; Grollier, J; Cros, V [Unite Mixte de Physique CNRS/Thales and Universite Paris Sud 11, Palaiseau (France); Avanesyan, G G; Zvezdin, K A, E-mail: michael.darques@uclouvain.be [A.M. Prokhorov General Physics Institute of RAS, Vavilova str. 38, Moscow (Russian Federation)

    2011-03-16

    We report on a bottom-up approach for the fabrication of spin-transfer nano-oscillators (STNOs). Porous alumina is used as a template for the growth by electrodeposition of metallic spin valves in series. Under specific magnetic field and injected current conditions, emission of microwave current is detected with frequency in the 1.5 GHz range and linewidth as low as 8 MHz. We find strong indications that the microwave emission is due to spin-transfer-driven vortex oscillations. This technique is promising for the fabrication of dense arrays of STNOs in view of device synchronization.

  5. Bottom-up assembly of hydrophobic nanocrystals and graphene nanosheets into mesoporous nanocomposites.

    Science.gov (United States)

    Huang, Jijiang; Liu, Wenxian; Wang, Li; Sun, Xiaoming; Huo, Fengwei; Liu, Junfeng

    2014-04-22

    A general strategy for constructing graphene-based nanocomposites is achieved by emulsion-based bottom-up self-assembly of hydrophobic nanocrystals (NCs) to positively charged colloidal spheres, followed by the electrostatic assembly of NC colloidal spheres with negatively charged graphene oxide in an acidulous aqueous solution. With a simple heat treatment, 3D mesoporous NC spheres/graphene composites are obtained. TiO2/graphene composites typically exhibit a better rate capability and cycle performance than do the corresponding isolated TiO2 spheres. PMID:24684553

  6. Assessment of the Bottom-up Budgeting Process for FY 2015

    OpenAIRE

    Manasan, Rosario G.

    2015-01-01

    The bottom-up budgeting (BUB) process is one of the major reform initiatives of the Aquino administration and has been tagged as such from several perspectives. First, it is seen as a component of its budget reform thrusts that are aimed at making the national government budgeting process more responsive to local needs. Second, the BUB is viewed as part of the democracy/empowerment reform as it opens another avenue for people`s participation in local planning and budgeting and for generating ...

  7. Representing energy technologies in top-down economic models using bottom-up information

    International Nuclear Information System (INIS)

    The rate and magnitude of technological change is a critical component in estimating future anthropogenic carbon emissions. We present a methodology for modeling low-carbon emitting technologies within the MIT Emissions Prediction and Policy Analysis (EPPA) model, a computable general equilibrium (CGE) model of the world economy. The methodology translates bottom-up engineering information for two carbon capture and sequestration (CCS) technologies in the electric power sector into the EPPA model and discusses issues that arise in assuring an accurate representation and realistic market penetration. We find that coal-based technologies with sequestration penetrate, despite their higher cost today, because of projected rising natural gas prices. (author)

  8. WORD-OF-MOUTH MARKETING AND ENTERPRISE STRATEGIES: A BOTTOM-UP DIFFUSION MODEL

    OpenAIRE

    Remondino, Marco

    2011-01-01

    A comprehensive simulation model is presented, aimed to show the dynamics of social diffusion based on the word of mouth (e.g.: viral marketing) over a social network of interconnected individuals. The model is build following a bottom-up approach and the agent based paradigm; this means that the dynamics of the diffusion is simulated in real time and generated at the micro level, not calculated by using mathematical formulas. This allows both to follow – step by step – the emergent process a...

  9. Supporting Frequent Updates in R-Trees: A Bottom-Up Approach

    DEFF Research Database (Denmark)

    Lee, Mong Li; Hsu, Wynne; Jensen, Christian Søndergaard; Cui, Bin; Teo, Keng Lik

    2004-01-01

    Advances in hardware-related technologies promise to enable new data management applications that monitor continuous processes. In these applications, enormous amounts of state samples are obtained via sensors and are streamed to a database. Further, updates are very frequent and may exhibit...... improve update performance. It has different levels of reorganization - ranging from global to local - during updates, avoiding expensive top-down updates. A compact main-memory summary structure that allows direct access to the R-tree index nodes is used together with efficient bottom-up algorithms...

  10. Reconciling Long-Term Trends in Air Quality with Bottom-up Emission Inventories for Los Angeles

    Science.gov (United States)

    Mcdonald, B. C.; Kim, S. W.; Frost, G. J.; Harley, R.; Trainer, M.

    2014-12-01

    Significant long-term changes in air quality have been observed in the United States over several decades. However, reconciling ambient observations with bottom-up emission inventories has proved challenging. In this study, we perform WRF-Chem modeling in the Los Angeles basin for carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and ozone (O3) over a long time period (1987-2010). To improve reconciliation of emission inventories with atmospheric observations, we incorporate new high-resolution emissions maps of a major to dominant source of urban air pollution, motor vehicles. A fuel-based approach is used to estimate motor vehicle emissions utilizing annual fuel sales reports, traffic count data that capture spatial and temporal patterns of vehicle activity, and pollutant emission factors measured from roadway studies performed over the last twenty years. We also update emissions from stationary sources using Continuous Emissions Monitoring Systems (CEMS) data when available, and use emission inventories developed by the South Coast Air Quality Management District (SCAQMD) and California Air Resources Board (ARB) for other important emission source categories. WRF-Chem modeling is performed in three years where field-intensive measurements were made: 1987 (SCAQS: Southern California Air Quality Study), 2002 (ITCT: Intercontinental Transport and Chemical Transformation Study), and 2010 (CALNEX). We assess the ability of the improved bottom-up emissions inventory to predict long-term changes in ambient levels of CO, NOx, and O3, which are known to have occurred over this time period. We also assess changing spatial and temporal patterns of primary (CO and NOx) and secondary (O3) pollutant concentrations across the Los Angeles basin, which has important implications on human health.

  11. Linking top-down and bottom-up approaches for assessing the vulnerability of a 100 % renewable energy system in Northern-Italy

    Science.gov (United States)

    Borga, Marco; Francois, Baptiste; Hingray, Benoit; Zoccatelli, Davide; Creutin, Jean-Dominique; brown, Casey

    2016-04-01

    Due to their variable and un-controllable features, integration of Variable Renewable Energies (e.g. solar-power, wind-power and hydropower, denoted as VRE) into the electricity network implies higher production variability and increased risk of not meeting demand. Two approaches are commonly used for assessing this risk and especially its evolution in a global change context (i.e. climate and societal changes); top-down and bottom-up approaches. The general idea of a top-down approach is to drive analysis of global change or of some key aspects of global change on their systems (e.g., the effects of the COP 21, of the deployment of Smart Grids, or of climate change) with chains of loosely linked simulation models within a predictive framework. The bottom-up approach aims to improve understanding of the dependencies between the vulnerability of regional systems and large-scale phenomenon from knowledge gained through detailed exploration of the response to change of the system of interest, which may reveal vulnerability thresholds, tipping points as well as potential opportunities. Brown et al. (2012) defined an analytical framework to merge these two approaches. The objective is to build, a set of Climate Response Functions (CRFs) putting in perspective i) indicators of desired states ("success") and undesired states ("failure") of a system as defined in collaboration with stakeholders 2) exhaustive exploration of the effects of uncertain forcings and imperfect system understanding on the response of the system itself to a plausible set of possible changes, implemented a with multi-dimensionally consistent "stress test" algorithm, and 3) a set "ex post" hydroclimatic and socioeconomic scenarios that provide insight into the differential effectiveness of alternative policies and serve as entry points for the provision of climate information to inform policy evaluation and choice. We adapted this approach for analyzing a 100 % renewable energy system within a region

  12. Bottom-up reconstruction scenarios for (un)constrained MSSM parameters at the CERN LHC

    International Nuclear Information System (INIS)

    We consider some specific inverse problem or 'bottom-up' reconstruction strategies at the CERN LHC for both general and constrained minimal supersymmetric standard model (MSSM) parameters, starting from a plausibly limited set of sparticle identification and mass measurements, using mainly gluino/squark cascade decays, plus eventually the lightest Higgs boson mass. For the three naturally separated sectors of gaugino/Higgsino, squark/slepton, and Higgs parameters, we examine different step-by-step algorithms based on rather simple, entirely analytical, inverted relations between masses and basic MSSM parameters. This includes also reasonably good approximations of some of the relevant radiative correction calculations. We distinguish the constraints obtained for a general MSSM from those obtained with universality assumptions in the three different sectors. Our results are compared at different stages with the determination from more standard 'top-down' fit of models to data, and finally combined into a global determination of all the relevant parameters. Our approach gives complementary information to more conventional analysis, and is not restricted to the specific LHC measurement specificities. In addition, the bottom-up renormalization group evolution of general MSSM parameters, being an important ingredient in this framework, is illustrated as a new publicly available option of the MSSM spectrum calculation code SuSpect.

  13. Bottom-up approach for decentralised energy planning: Case study of Tumkur district in India

    International Nuclear Information System (INIS)

    Decentralized Energy Planning (DEP) is one of the options to meet the rural and small-scale energy needs in a reliable, affordable and environmentally sustainable way. The main aspect of the energy planning at decentralized level would be to prepare an area-based DEP to meet energy needs and development of alternate energy sources at least-cost to the economy and environment. Present work uses goal-programming method in order to analyze the DEP through bottom-up approach. This approach includes planning from the lowest scale of Tumkur district in India. The scale of analysis included village level-Ungra, panchayat level (local council)-Yedavani, block level-Kunigal and district level-Tumkur. The approach adopted was bottom-up (village to district) to allow a detailed description of energy services and the resulting demand for energy forms and supply technologies. Different scenarios are considered at four decentralized scales for the year 2005 and are developed and analyzed for the year 2020. Decentralized bioenergy system for producing biogas and electricity, using local biomass resources, are shown to promote development compared to other renewables. This is because, apart from meeting energy needs, multiple goals could be achieved such as self-reliance, local employment, and land reclamation apart from CO2 emissions reduction.

  14. Dynamic formulation of a top-down and bottom-up merging energy policy model

    International Nuclear Information System (INIS)

    The impact of energy policy measures is not restricted to the energy system and should therefore be analysed within an economy-wide framework, while keeping the essential details of the energy sector. The aim of this paper is to present new developments in the field of the consistent evaluation of indicators for the sustainability assessment of energy policy measures. Starting from the static concept of Boehringer (Energy Econ. 20 (1998) 233), this paper shows how the complementarity format can be used in computable general equilibrium (CGE) modelling for a dynamic formulation of bottom-up and top-down approach merging models. While a hybrid approach increases the credibility of CGE models in energy policy analysis by replacing the energy sector generic functional forms with a bottom-up activity analysis based on specific technologies, the endogenous formulation of investment decisions makes an explicit description of evolving specific capital stocks and technology mixes possible. Both features are essential when assessing effects of policy measures that may be affected by structural change--which is typically the case in the long-term assessment of energy policy measures

  15. Dynamic formulation of a top-down and bottom-up merging energy policy model

    Energy Technology Data Exchange (ETDEWEB)

    Frei, C.W. [Swiss Federal Inst. of Technology, Lausanne (Switzerland). Centre for Energy Policy and Economics; Haldi, P.A.; Sarlos, G. [Swiss Federal Inst. of Technology, Lausanne (Switzerland). Lab. of Energy Systems

    2003-08-01

    The impact of energy policy measures is not restricted to the energy system and should therefore be analysed within an economy-wide framework, while keeping the essential details of the energy sector. The aim of this paper is to present new developments in the field of the consistent evaluation of indicators for the sustainability assessment of energy policy measures. Starting from the static concept of Boehringer (Energy Econ. 20 (1998) 233), this paper shows how the complementarity format can be used in computable general equilibrium (CGE) modelling for a dynamic formulation of bottom-up and top-down approach merging models. While a hybrid approach increases the credibility of CGE models in energy policy analysis by replacing the energy sector generic functional forms with a bottom-up activity analysis based on specific technologies, the endogenous formulation of investment decisions makes an explicit description of evolving specific capital stocks and technology mixes possible. Both features are essential when assessing effects of policy measures that may be affected by structural change - which is typically the case in the long-term assessment of energy policy measures.(author)

  16. From bottom-up approaches to levels of organization and extended critical transitions

    Directory of Open Access Journals (Sweden)

    Giuseppe eLongo

    2012-07-01

    Full Text Available Biological thinking is structured by the notion of level of organization. We will show that this notion acquires a precise meaning in critical phenomena: they disrupt, by the appearance of infinite quantities, the mathematical (possibly equational determination at a given level, when moving at an ``higher'' one. As a result, their analysis cannot be called genuinely bottom-up, even though it remains upward in a restricted sense.At the same time, criticality and related phenomena are very common in biology. Because of this, we claim that bottom-up approaches are not sufficient, in principle, to capture biological phenomena. In the second part of this paper, following the work of Francis Bailly, we discuss a strong criterium of level transition. The core idea of the criterium is to start from the breaking of the symmetries and determination at a ``first'' level in order to ``move'' at the others. If biological phenomena have multiple, emph{sustained} levels of organization in this sense, then they should be interpreted as emph{extended} critical transitions.

  17. A bottom-up institutional approach to cooperative governance of risky commons

    Science.gov (United States)

    Vasconcelos, Vítor V.; Santos, Francisco C.; Pacheco, Jorge M.

    2013-09-01

    Avoiding the effects of climate change may be framed as a public goods dilemma, in which the risk of future losses is non-negligible, while realizing that the public good may be far in the future. The limited success of existing attempts to reach global cooperation has been also associated with a lack of sanctioning institutions and mechanisms to deal with those who do not contribute to the welfare of the planet or fail to abide by agreements. Here we investigate the emergence and impact of different types of sanctioning to deter non-cooperative behaviour in climate agreements. We show that a bottom-up approach, in which parties create local institutions that punish free-riders, promotes the emergence of widespread cooperation, mostly when risk perception is low, as it is at present. On the contrary, global institutions provide, at best, marginal improvements regarding overall cooperation. Our results clearly suggest that a polycentric approach involving multiple institutions is more effective than that associated with a single, global one, indicating that such a bottom-up, self-organization approach, set up at a local scale, provides a better ground on which to attempt a solution for such a complex and global dilemma.

  18. Formation of three-dimensional hepatic tissue by the bottom-up method using spheroids.

    Science.gov (United States)

    Okudaira, Tatsuya; Amimoto, Naoki; Mizumoto, Hiroshi; Kajiwara, Toshihisa

    2016-08-01

    Liver regenerative medicine has attracted attention as a possible alternative to organ transplantation. To address the challenge of liver regenerative medicine, the development of a construction method has been proposed for liver tissue in vitro with a high cell density and high functionality for transplantation into patients with severe liver failure. In this study, we fabricated highly functional three-dimensional hepatic tissue by a bottom-up method using spheroids. The hepatic tissue was formed by stacking hepatocyte spheroids covered with human umbilical vein endothelial cells (HUVECs). Hepatic tissue constructs were evaluated for cell survival, liver-specific functions, and histologically. As a result, we identified improvements in liver-specific functions (ammonia removal and albumin secretion) and cell survival. In addition, HUVECs were regularly distributed at every 100 μm within the tissue, and live cells were present within the whole tissue construct throughout the culture period. In summary, we successfully fabricated highly functional hepatic tissue by the bottom-up method using HUVEC-covered hepatocyte spheroids. PMID:26803704

  19. A bottom-up approach for the synthesis of highly ordered fullerene-intercalated graphene hybrids

    Directory of Open Access Journals (Sweden)

    Dimitrios eGournis

    2015-02-01

    Full Text Available Much of the research effort on graphene focuses on its use as a building block for the development of new hybrid nanostructures with well-defined dimensions and properties suitable for applications such as gas storage, heterogeneous catalysis, gas/liquid separations, nanosensing and biomedicine. Towards this aim, here we describe a new bottom-up approach, which combines self-assembly with the Langmuir Schaefer deposition technique to synthesize graphene-based layered hybrid materials hosting fullerene molecules within the interlayer space. Our film preparation consists in a bottom-up layer-by-layer process that proceeds via the formation of a hybrid organo-graphene oxide Langmuir film. The structure and composition of these hybrid fullerene-containing thin multilayers deposited on hydrophobic substrates were characterized by a combination of X-ray diffraction, Raman and X-ray photoelectron spectroscopies, atomic force microscopy and conductivity measurements. The latter revealed that the presence of C60 within the interlayer spacing leads to an increase in electrical conductivity of the hybrid material as compared to the organo-graphene matrix alone.

  20. The Challenge of Bottom-Up Paradigm and Popular Participation in Sustainable Rural Development of Nigeria: The Way Forward

    OpenAIRE

    J. O. Adefila

    2012-01-01

    The paper is entitled ‘The challenge of bottom-up paradigm and popular participation in rural economic development of Nigeria’. There is the clamour for a shift from centre-down to bottom-up paradigm particularly among the rural developers considering the back-wash effects of the latter which tends to undermine the economic growth and development of the rural areas. The paper aims at reinforcing the adoption of bottom-up and popular participation approaches to rural socio-economic transformat...

  1. Integrating the bottom-up and top-down approach to energy economy modelling. The case of Denmark

    DEFF Research Database (Denmark)

    Klinge Jacobsen, Henrik

    1998-01-01

    This paper presents results from an integration project covering Danish models based on bottom-up and top-down approaches to energy]economy modelling. The purpose of the project was to identify theoretical and methodological problems for integrating existing models for Denmark and to implement an...... integration of the models. The integration was established through a number of links between energy bottom-up modules and a macroeconomic model. In this integrated model it is possible to analyse both top-down instruments, such as taxes along with bottom-up instruments, such as regulation of technology...

  2. Top-down and bottom-up lipidomic analysis of rabbit lipoproteins under different metabolic conditions using flow field-flow fractionation, nanoflow liquid chromatography and mass spectrometry.

    Science.gov (United States)

    Byeon, Seul Kee; Kim, Jin Yong; Lee, Ju Yong; Chung, Bong Chul; Seo, Hong Seog; Moon, Myeong Hee

    2015-07-31

    This study demonstrated the performances of top-down and bottom-up approaches in lipidomic analysis of lipoproteins from rabbits raised under different metabolic conditions: healthy controls, carrageenan-induced inflammation, dehydration, high cholesterol (HC) diet, and highest cholesterol diet with inflammation (HCI). In the bottom-up approach, the high density lipoproteins (HDL) and the low density lipoproteins (LDL) were size-sorted and collected on a semi-preparative scale using a multiplexed hollow fiber flow field-flow fractionation (MxHF5), followed by nanoflow liquid chromatography-ESI-MS/MS (nLC-ESI-MS/MS) analysis of the lipids extracted from each lipoprotein fraction. In the top-down method, size-fractionated lipoproteins were directly infused to MS for quantitative analysis of targeted lipids using chip-type asymmetrical flow field-flow fractionation-electrospray ionization-tandem mass spectrometry (cAF4-ESI-MS/MS) in selected reaction monitoring (SRM) mode. The comprehensive bottom-up analysis yielded 122 and 104 lipids from HDL and LDL, respectively. Rabbits within the HC and HCI groups had lipid patterns that contrasted most substantially from those of controls, suggesting that HC diet significantly alters the lipid composition of lipoproteins. Among the identified lipids, 20 lipid species that exhibited large differences (>10-fold) were selected as targets for the top-down quantitative analysis in order to compare the results with those from the bottom-up method. Statistical comparison of the results from the two methods revealed that the results were not significantly different for most of the selected species, except for those species with only small differences in concentration between groups. The current study demonstrated that top-down lipid analysis using cAF4-ESI-MS/MS is a powerful high-speed analytical platform for targeted lipidomic analysis that does not require the extraction of lipids from blood samples. PMID:26087967

  3. Top-Down and Bottom-Up Approaches in 3D Printing Technologies for Drug Delivery Challenges.

    Science.gov (United States)

    Katakam, Prakash; Dey, Baishakhi; Assaleh, Fathi H; Hwisa, Nagiat Tayeb; Adiki, Shanta Kumari; Chandu, Babu Rao; Mitra, Analava

    2015-01-01

    3-Dimensional printing (3DP) constitutes a raft of technologies, based on different physical mechanisms, that generate a 3-dimensional physical object from a digital model. Because of its rapid fabrication and precise geometry, 3DP has gained a prominent focus in biomedical and nanobiomaterials research. Despite advancements in targeted, controlled, and pulsatile drug delivery, the achievement of site-specific and disease-responsive drug release and stringent control over in vivo biodistribution, are still some of the important, challenging areas for pharmaceutical research and development and existing drug delivery techniques. Microelectronic industries are capable of generating nano-/microdrug delivery devices at high throughputs with a highly precise control over design. Successful miniaturizations of micro-pumps with multireservoir architectures for delivery of pharmaceuticals developed by micro-electromechanical systems technology were more acceptable than implantable devices. Inkjet printing technologies, which dispense a precise amount of polymer ink solutions, find applications in controlled drug delivery. Bioelectronic products have revolutionized drug delivery technologies. Designing nanoparticles by nanoimprint lithography showed a controlled drug release pattern, biodistribution, and in vivo transport. This review highlights the "top-down" and "bottom-up" approaches of the most promising 3DP technologies and their broader applications in biomedical and therapeutic drug delivery, with critical assessment of its merits, demerits, and intellectual property rights challenges. PMID:25746205

  4. Saccade generation by the frontal eye fields in rhesus monkeys is separable from visual detection and bottom-up attention shift.

    Directory of Open Access Journals (Sweden)

    Kyoung-Min Lee

    Full Text Available The frontal eye fields (FEF, originally identified as an oculomotor cortex, have also been implicated in perceptual functions, such as constructing a visual saliency map and shifting visual attention. Further dissecting the area's role in the transformation from visual input to oculomotor command has been difficult because of spatial confounding between stimuli and responses and consequently between intermediate cognitive processes, such as attention shift and saccade preparation. Here we developed two tasks in which the visual stimulus and the saccade response were dissociated in space (the extended memory-guided saccade task, and bottom-up attention shift and saccade target selection were independent (the four-alternative delayed saccade task. Reversible inactivation of the FEF in rhesus monkeys disrupted, as expected, contralateral memory-guided saccades, but visual detection was demonstrated to be intact at the same field. Moreover, saccade behavior was impaired when a bottom-up shift of attention was not a prerequisite for saccade target selection, indicating that the inactivation effect was independent of the previously reported dysfunctions in bottom-up attention control. These findings underscore the motor aspect of the area's functions, especially in situations where saccades are generated by internal cognitive processes, including visual short-term memory and long-term associative memory.

  5. Succumbing to Bottom-Up Biases on Task Choice Predicts Increased Switch Costs in the Voluntary Task Switching Paradigm

    OpenAIRE

    JosephMichaelOrr

    2011-01-01

    Bottom-up biases are widely thought to influence task choice in the voluntary task switching paradigm. Definitive support for this hypothesis is lacking, however, because task choice and task performance are usually confounded. We therefore revisited this hypothesis using a paradigm in which task choice and task performance are temporally separated. As predicted, participants tended to choose the task that was primed by bottom-up biases. Moreover, such choices were linked to increased swit...

  6. Unsupervised Tattoo Segmentation Combining Bottom-Up and Top-Down Cues

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Josef D [ORNL

    2011-01-01

    Tattoo segmentation is challenging due to the complexity and large variance in tattoo structures. We have developed a segmentation algorithm for nding tattoos in an image. Our basic idea is split-merge: split each tattoo image into clusters through a bottom-up process, learn to merge the clusters containing skin and then distinguish tattoo from the other skin via top-down prior in the image itself. Tattoo segmentation with unknown number of clusters is transferred to a gure-ground segmentation. We have applied our segmentation algorithm on a tattoo dataset and the results have shown that our tattoo segmentation system is e cient and suitable for further tattoo classi cation and retrieval purpose.

  7. Enhancing Bottom-up and Top-down Proteomic Measurements with Ion Mobility Separations

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Erin Shammel [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burnum-Johnson, Kristin E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ibrahim, Yehia M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Orton, Daniel J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Monroe, Matthew E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kelly, Ryan T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moore, Ronald J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Xing [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Theberge, Roger [Boston Univ. of Medicine, MA (United States); Costello, Catherine E. [Boston Univ. of Medicine, MA (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-03

    Proteomic measurements with greater throughput, sensitivity and additional structural information enhance the in-depth characterization of complex mixtures and targeted studies with additional information and higher confidence. While liquid chromatography separation coupled with mass spectrometry (LC-MS) measurements have provided information on thousands of proteins in different sample types, the additional of another rapid separation stage providing structural information has many benefits for analyses. Technical advances in ion funnels and multiplexing have enabled ion mobility separations to be easily and effectively coupled with LC-MS proteomics to enhance the information content of measurements. Herein, we report on applications illustrating increased sensitivity, throughput, and structural information by utilizing IMS-MS and LC-IMS-MS measurements for both bottom-up and top-down proteomics measurements.

  8. A bottom-up perspective on leadership of collaborative innovation in the public sector

    DEFF Research Database (Denmark)

    Hansen, Jesper Rohr

    organizations. A crucial condition for success is iterative leadership adaptation. In conclusion, the thesis finds that specialized professionals are indeed able to develop politically viable, innovative and collaborative solutions to wicked problems; and that such professionals are able to transform themselves......The thesis investigates how new forms of public leadership can contribute to solving complex problems in today’s welfare societies through innovation. A bottom-up type of leadership for collaborative innovation addressing wicked problems is theorised, displaying a social constructive process...... approach to leadership; a theoretical model emphasises that leadership emerges through social processes of recognition. Leadership is recognised by utilising the uncertainty of a wicked problem and innovation to influence collaborators’ sensemaking processes. The empirical setting is the City of Copenhagen...

  9. Bottom-Up Cost Analysis of a High Concentration PV Module; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, K.; Woodhouse, M.; Lee, H.; Smestad, G.

    2015-04-13

    We present a bottom-up model of III-V multi-junction cells, as well as a high concentration PV (HCPV) module. We calculate $0.65/Wp(DC) manufacturing costs for our model HCPV module design with today’s capabilities, and find that reducing cell costs and increasing module efficiency offer the promising pathways for future cost reductions. Cell costs could be significantly reduced via an increase in manufacturing scale, substrate reuse, and improved manufacturing yields. We also identify several other significant drivers of HCPV module costs, including the Fresnel lens primary optic, module housing, thermal management, and the receiver board. These costs could potentially be lowered by employing innovative module designs.

  10. Coupled multi-physics simulation frameworks for reactor simulation: A bottom-up approach

    International Nuclear Information System (INIS)

    In this paper, we present a 'bottom-up' approach to multi-physics frameworks, where we first develop common interfaces to simulation data, then adapt existing physics modules to communicate through those interfaces. Interfaces are provided for geometry, mesh, and field data, and are independent of one another; a fourth interface is available for relating data between these interfaces. Physics modules read and write data through those common interfaces, which also provide access to common simulation services like parallel IO, mesh partitioning, etc. Multi-physics codes are assembled as a combination of physics modules, services, interface implementations, and driver code which coordinates calling these various pieces. The framework being constructed as part of this effort, referred to as SHARP, is shown

  11. Strain Response of Hot-Mix Asphalt Overlays for Bottom-Up Reflective Cracking

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

    This paper examines the strain response of typical HMA overlays above jointed PCC slabs prone to bottom-up reflective cracking. The occurrence of reflective cracking under the combined effect of traffic and environmental loading significantly reduces the design life of the HMA overlays and can lead to its premature failure. In this context, viscoelastic material properties combined with cyclic vehicle loadings and pavement temperature distribution were implemented in a series of FE models in order to study the evolution of horizontal tensile and shear strains at the bottom of the HMA overlay. The effect of several design parameters, such as subbase and subgrade moduli, vehicle speed, overlay thickness, and temperature condition, on the horizontal and shear strain response was investigated. Results obtained show that the rate of horizontal and shear strain increase at the bottom of the HMA overlay drop with higher vehicle speed, higher subgrade modulus, and higher subbase modulus. Moreover, the rate of horizon...

  12. Collective Inclusioning: A Grounded Theory of a Bottom-Up Approach to Innovation and Leading

    Directory of Open Access Journals (Sweden)

    Michal Lysek

    2016-06-01

    Full Text Available This paper is a grounded theory study of how leaders (e.g., entrepreneurs, managers, etc. engage people in challenging undertakings (e.g., innovation that require everyone’s commitment to such a degree that they would have to go beyond what could be reasonably expected in order to succeed. Company leaders sometimes wonder why their employees no longer show the same responsibility towards their work, and why they are more concerned with internal politics than solving customer problems. It is because company leaders no longer apply collective inclusioning to the same extent as they did in the past. Collective inclusioning can be applied in four ways by convincing, afinitizing, goal congruencing, and engaging. It can lead to fostering strong units of people for taking on challenging undertakings. Collective inclusioning is a complementing theory to other strategic management and leading theories. It offers a new perspective on how to implement a bottom-up approach to innovation.

  13. Bottom-Up Nanofabrication of Supported Noble Metal Alloy Nanoparticle Arrays for Plasmonics

    DEFF Research Database (Denmark)

    Nugroho, Ferry A. A.; Iandolo, Beniamino; Wagner, Jakob Birkedal; Langhammer, Christoph

    2016-01-01

    concept, we focus on Au-based binary and ternary alloy systems with Ag, Cu, and Pd, due to their high relevance for nanoplasmonics and complete miscibility, and characterize their optical properties. Moreover, as an example for the relevance of the obtained materials for integration in devices, we......Mixing different elements at the nanoscale to obtain alloy nanostructures with fine-tuned physical and chemical properties offers appealing opportunities for nanotechnology and nanoscience. However, despite widespread successful application of alloy nanoparticles made by colloidal synthesis in...... optimization of the surface density. These cannot be fulfilled even using state-of-the-art self -assembly strategies of colloids. As a solution, we present here a generic bottom-up nanolithography-compatible fabrication approach for large-area arrays of alloy nanoparticles on surfaces. To illustrate the...

  14. Manufacturing at Nanoscale: Top-Down, Bottom-up and System Engineering

    International Nuclear Information System (INIS)

    The current nano-technology revolution is facing several major challenges: to manufacture nanodevices below 20 nm, to fabricate three-dimensional complex nano-structures, and to heterogeneously integrate multiple functionalities. To tackle these grand challenges, the Center for Scalable and Integrated NAno-Manufacturing (SINAM), a NSF Nanoscale Science and Engineering Center, set its goal to establish a new manufacturing paradigm that integrates an array of new nano-manufacturing technologies, including the plasmonic imaging lithography and ultramolding imprint lithography aiming toward critical resolution of 1-10 nm and the hybrid top-down and bottom-up technologies to achieve massively parallel integration of heterogeneous nanoscale components into higher-order structures and devices. Furthermore, SINAM will develop system engineering strategies to scale-up the nano-manufacturing technologies. SINAMs integrated research and education platform will shed light to a broad range of potential applications in computing, telecommunication, photonics, biotechnology, health care, and national security

  15. Using dichotic listening to study bottom-up and top-down processing in children and adults.

    Science.gov (United States)

    Andersson, Martin; Llera, John Eric; Rimol, Lars M; Hugdahl, Kenneth

    2008-09-01

    The study examined top-down attention modulation of bottom-up processing in children and adults under conditions of varying bottom-up stimulus demands. Voiced and unvoiced consonant-vowel syllables were used in a dichotic-listening situation to manipulate the strength of the bottom-up stimulus-driven right ear advantage when subjects were instructed to focus attention on, and report, either the left or right ear stimulus. We predicted that children would differ from adults in their ability to use attention to modulate a lateralized ear advantage, and particularly when there was a conflict between the direction of the bottom-up ear advantage and the direction of the top-down attention instruction. Thirty children and 30 adults were presented with dichotic presentations of consonant-vowel syllables. The results showed that the voicing manipulation affected the strength of the ear advantage, and that the children performed significantly below the adults when the voicing parameter caused a strong conflict between bottom-up and top down processing. Thus, children seem to lack the cognitive flexibility necessary to modulate a stimulus-driven bottom-up ear advantage, particularly in situations where right ear advantage (REA) is enhanced by the acoustic properties of the stimuli and attentional demands require a left ear shift. It is suggested that varying the stimulus demands in a dichotic-listening situation may be a novel way to study cognitive development. PMID:18608228

  16. Achieving social-ecological fit through bottom-up collaborative governance: an empirical investigation

    Directory of Open Access Journals (Sweden)

    Angela M. Guerrero

    2015-12-01

    Full Text Available Significant benefits can arise from collaborative forms of governance that foster self-organization and flexibility. Likewise, governance systems that fit with the extent and complexity of the system under management are considered essential to our ability to solve environmental problems. However, from an empirical perspective the fundamental question of whether self-organized (bottom-up collaborative forms of governance are able to accomplish adequate fit is unresolved. We used new theory and methodological approaches underpinned by interdisciplinary network analysis to address this gap by investigating three governance challenges that relate to the problem of fit: shared management of ecological resources, management of interconnected ecological resources, and cross-scale management. We first identified a set of social-ecological network configurations that represent the hypothesized ways in which collaborative arrangements can contribute to addressing these challenges. Using social and ecological data from a large-scale biodiversity conservation initiative in Australia, we empirically determined how well the observed patterns of stakeholder interactions reflect these network configurations. We found that stakeholders collaborate to manage individual parcels of native vegetation, but not for the management of interconnected parcels. In addition, our data show that the collaborative arrangements enable management across different scales (local, regional, supraregional. Our study provides empirical support for the ability of collaborative forms of governance to address the problem of fit, but also suggests that in some cases the establishment of bottom-up collaborative arrangements would likely benefit from specific guidance to facilitate the establishment of collaborations that better align with the ways ecological resources are interconnected across the landscape. In our case study region, this would improve the capacity of stakeholders to

  17. Top-down and bottom-up approaches for cost estimating new reactor designs

    International Nuclear Information System (INIS)

    For several years, Generation-4 designs will be 'pre-conceptual' for the less mature concepts and 'preliminary' for the more mature concepts. In this situation, appropriate data for some of the plant systems may be lacking to develop a bottom-up cost estimate. Therefore, a more global approach, the Top-Down Approach (TDA), is needed to help the designers and decision makers in comparing design options. It utilizes more or less simple models for cost estimating the different parts of a design. TDA cost estimating effort applies to a whole functional element whose cost is approached by similar estimations coming from existing data, ratios and models, for a given range of variation of parameters. Modeling is used when direct analogy is not possible. There are two types of models, global and specific ones. Global models are applied to cost modules related to Code Of Account. Exponential formulae such as Ci = Ai + (Bi x Pin) are used when there are cost data for comparable modules in nuclear or other industries. Specific cost models are developed for major specific components of the plant: - process equipment such as reactor vessel, steam generators or large heat exchangers. - buildings, with formulae estimating the construction cost from base cost of m3 of building volume. - systems, when unit costs, cost ratios and models are used, depending on the level of detail of the design. Bottom Up Approach (BUA), which is based on unit prices coming from similar equipment or from manufacturer consulting, is very valuable and gives better cost estimations than TDA when it can be applied, that is at a rather late stage of the design. Both approaches are complementary when some parts of the design are detailed enough to be estimated by BUA, and when BUA results are used to check TDA results and to improve TDA models. This methodology is applied to the HTR (High Temperature Reactor) concept and to an advanced PWR design

  18. Top-down instead of bottom-up estimates of uncertainty in INAA results?

    International Nuclear Information System (INIS)

    The initial publication of the ISO Guide to the Expression of Uncertainty in Measurement (GUM) and many related documents has resulted in a worldwide awareness of the importance of a realistic estimate of the value reported after the +/- sign. The evaluation of uncertainty in measurement, as introduced by the GUM, is derived from the principles applied in physical measurements. Many testing laboratories have already experienced large problems in applying these principles in e.g. (bio)chemical measurements, resulting in time-consuming evaluations and costly additional experiments. Other, more pragmatic and less costly approaches have been proposed to obtain a realistic estimate of the range in which the true value of the measurement may be found with a certain degree of probability. One of these approaches, the 'top-down method', is based on the standard deviation in the results of intercomparison data. This approach is much easier for tests for which it is either difficult to establish a full measurement equation, or if e.g. matrix-matching reference materials are absent. It has been demonstrated that the GUM 'bottom-up' approach of evaluating uncertainty in measurement can easily be applied in instrumental neutron activation analysis (INAA) as all significant sources of uncertainty can be evaluated. INAA is therefore a valuable technique to test the validity of the top-down approach. In this contribution, examples of the top-down evaluation of uncertainty in INAA derived from participation in intercomparison rounds and proficiency testing schemes will be presented. The results will be compared with the bottom-up evaluation of uncertainty, and ease of applicability, validity and usefullness of both approaches will be discussed.

  19. Estimation of Emissions from Sugarcane Field Burning in Thailand Using Bottom-Up Country-Specific Activity Data

    Directory of Open Access Journals (Sweden)

    Wilaiwan Sornpoon

    2014-09-01

    Full Text Available Open burning in sugarcane fields is recognized as a major source of air pollution. However, the assessment of its emission intensity in many regions of the world still lacks information, especially regarding country-specific activity data including biomass fuel load and combustion factor. A site survey was conducted covering 13 sugarcane plantations subject to different farm management practices and climatic conditions. The results showed that pre-harvest and post-harvest burnings are the two main practices followed in Thailand. In 2012, the total production of sugarcane biomass fuel, i.e., dead, dry and fresh leaves, amounted to 10.15 million tonnes, which is equivalent to a fuel density of 0.79 kg∙m−2. The average combustion factor for the pre-harvest and post-harvest burning systems was determined to be 0.64 and 0.83, respectively. Emissions from sugarcane field burning were estimated using the bottom-up country-specific values from the site survey of this study and the results compared with those obtained using default values from the 2006 IPCC Guidelines. The comparison showed that the use of default values lead to underestimating the overall emissions by up to 30% as emissions from post-harvest burning are not accounted for, but it is the second most common practice followed in Thailand.

  20. Exploring the Life Expectancy Increase in Poland in the Context of CVD Mortality Fall: The Risk Assessment Bottom-Up Approach, From Health Outcome to Policies.

    Science.gov (United States)

    Kobza, Joanna; Geremek, Mariusz

    2015-01-01

    Life expectancy at birth is considered the best mortality-based summary indicator of the health status of the population and is useful for measuring long-term health changes. The objective of this article was to present the concept of the bottom-up policy risk assessment approach, developed to identify challenges involved in analyzing risk factor reduction policies and in assessing how the related health indicators have changed over time. This article focuses on the reasons of the significant life expectancy prolongation in Poland over the past 2 decades, thus includes policy context. The methodology details a bottom-up risk assessment approach, a chain of relations between the health outcome, risk factors, and health policy, based on Risk Assessment From Policy to Impact Dimension project guidance. A decline in cardiovascular disease mortality was a key factor that followed life expectancy prolongation. Among basic factors, tobacco and alcohol consumption, diet, physical activity, and new treatment technologies were identified. Poor health outcomes of the Polish population at the beginning of 1990s highlighted the need of the implementation of various health promotion programs, legal acts, and more effective public health policies. Evidence-based public health policy needs translating scientific research into policy and practice. The bottom-up case study template can be one of the focal tools in this process. Accountability for the health impact of policies and programs and legitimization of the decisions of policy makers has become one of the key questions nowadays in European countries' decision-making process and in EU public health strategy. PMID:26546595

  1. A bottom-up approach to estimating cost elements of REDD+ pilot projects in Tanzania

    Directory of Open Access Journals (Sweden)

    Merger Eduard

    2012-08-01

    Full Text Available Abstract Background Several previous global REDD+ cost studies have been conducted, demonstrating that payments for maintaining forest carbon stocks have significant potential to be a cost-effective mechanism for climate change mitigation. These studies have mostly followed highly aggregated top-down approaches without estimating the full range of REDD+ costs elements, thus underestimating the actual costs of REDD+. Based on three REDD+ pilot projects in Tanzania, representing an area of 327,825 ha, this study explicitly adopts a bottom-up approach to data assessment. By estimating opportunity, implementation, transaction and institutional costs of REDD+ we develop a practical and replicable methodological framework to consistently assess REDD+ cost elements. Results Based on historical land use change patterns, current region-specific economic conditions and carbon stocks, project-specific opportunity costs ranged between US$ -7.8 and 28.8 tCOxxxx for deforestation and forest degradation drivers such as agriculture, fuel wood production, unsustainable timber extraction and pasture expansion. The mean opportunity costs for the three projects ranged between US$ 10.1 – 12.5 tCO2. Implementation costs comprised between 89% and 95% of total project costs (excluding opportunity costs ranging between US$ 4.5 - 12.2 tCO2 for a period of 30 years. Transaction costs for measurement, reporting, verification (MRV, and other carbon market related compliance costs comprised a minor share, between US$ 0.21 - 1.46 tCO2. Similarly, the institutional costs comprised around 1% of total REDD+ costs in a range of US$ 0.06 – 0.11 tCO2. Conclusions The use of bottom-up approaches to estimate REDD+ economics by considering regional variations in economic conditions and carbon stocks has been shown to be an appropriate approach to provide policy and decision-makers robust economic information on REDD+. The assessment of opportunity costs is a crucial first step to

  2. Conservative and dissipative force field for simulation of coarse-grained alkane molecules: a bottom-up approach.

    Science.gov (United States)

    Trément, Sébastien; Schnell, Benoît; Petitjean, Laurent; Couty, Marc; Rousseau, Bernard

    2014-04-01

    We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems. PMID:24712786

  3. Conservative and dissipative force field for simulation of coarse-grained alkane molecules: A bottom-up approach

    Energy Technology Data Exchange (ETDEWEB)

    Trément, Sébastien; Rousseau, Bernard, E-mail: bernard.rousseau@u-psud.fr [Laboratoire de Chimie-Physique, UMR 8000 CNRS, Université Paris-Sud, Orsay (France); Schnell, Benoît; Petitjean, Laurent; Couty, Marc [Manufacture Française des Pneumatiques MICHELIN, Centre de Ladoux, 23 place des Carmes, 63000 Clermont-Ferrand (France)

    2014-04-07

    We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems.

  4. Conservative and dissipative force field for simulation of coarse-grained alkane molecules: A bottom-up approach

    International Nuclear Information System (INIS)

    We apply operational procedures available in the literature to the construction of coarse-grained conservative and friction forces for use in dissipative particle dynamics (DPD) simulations. The full procedure rely on a bottom-up approach: large molecular dynamics trajectories of n-pentane and n-decane modeled with an anisotropic united atom model serve as input for the force field generation. As a consequence, the coarse-grained model is expected to reproduce at least semi-quantitatively structural and dynamical properties of the underlying atomistic model. Two different coarse-graining levels are studied, corresponding to five and ten carbon atoms per DPD bead. The influence of the coarse-graining level on the generated force fields contributions, namely, the conservative and the friction part, is discussed. It is shown that the coarse-grained model of n-pentane correctly reproduces self-diffusion and viscosity coefficients of real n-pentane, while the fully coarse-grained model for n-decane at ambient temperature over-predicts diffusion by a factor of 2. However, when the n-pentane coarse-grained model is used as a building block for larger molecule (e.g., n-decane as a two blobs model), a much better agreement with experimental data is obtained, suggesting that the force field constructed is transferable to large macro-molecular systems

  5. Pressurized Pepsin Digestion in Proteomics: An Automatable Alternative to Trypsin for Integrated Top-down Bottom-up Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ferrer, Daniel; Petritis, Konstantinos; Robinson, Errol W.; Hixson, Kim K.; Tian, Zhixin; Lee, Jung Hwa; Lee, Sang-Won; Tolic, Nikola; Weitz, Karl K.; Belov, Mikhail E.; Smith, Richard D.; Pasa-Tolic, Ljiljana

    2011-02-01

    Integrated top-down bottom-up proteomics combined with online digestion has great potential to improve the characterization of protein isoforms in biological systems and is amendable to highthroughput proteomics experiments. Bottom-up proteomics ultimately provides the peptide sequences derived from the tandem MS analyses of peptides after the proteome has been digested. Top-down proteomics conversely entails the MS analyses of intact proteins for more effective characterization of genetic variations and/or post-translational modifications (PTMs). Herein, we describe recent efforts towards efficient integration of bottom-up and top-down LCMS based proteomic strategies. Since most proteomic platforms (i.e. LC systems) operate in acidic environments, we exploited the compatibility of the pepsin (i.e. the enzyme’s natural acidic activity) for the integration of bottom-up and top-down proteomics. Pressure enhanced pepsin digestions were successfully performed and characterized with several standard proteins in either an offline mode using a Barocycler or an online mode using a modified high pressure LC system referred to as a fast online digestion system (FOLDS). FOLDS was tested using pepsin and a whole microbial proteome, and the results compared against traditional trypsin digestions on the same platform. Additionally, FOLDS was integrated with a RePlay configuration to demonstrate an ultra-rapid integrated bottom-up top-down proteomic strategy employing a standard mixture of proteins and a monkey pox virus proteome.

  6. Bottom-up and top-down influences at untrained conditions determine perceptual learning specificity and transfer

    Science.gov (United States)

    Xiong, Ying-Zi; Zhang, Jun-Yun; Yu, Cong

    2016-01-01

    Perceptual learning is often orientation and location specific, which may indicate neuronal plasticity in early visual areas. However, learning specificity diminishes with additional exposure of the transfer orientation or location via irrelevant tasks, suggesting that the specificity is related to untrained conditions, likely because neurons representing untrained conditions are neither bottom-up stimulated nor top-down attended during training. To demonstrate these top-down and bottom-up contributions, we applied a “continuous flash suppression” technique to suppress the exposure stimulus into sub-consciousness, and with additional manipulations to achieve pure bottom-up stimulation or top-down attention with the transfer condition. We found that either bottom-up or top-down influences enabled significant transfer of orientation and Vernier discrimination learning. These results suggest that learning specificity may result from under-activations of untrained visual neurons due to insufficient bottom-up stimulation and/or top-down attention during training. High-level perceptual learning thus may not functionally connect to these neurons for learning transfer. DOI: http://dx.doi.org/10.7554/eLife.14614.001 PMID:27377357

  7. Bottom-up control of geomagnetic secular variation by the Earth's inner core

    DEFF Research Database (Denmark)

    Aubert, Julien; Finlay, Chris; Fournier, Alexandre

    2013-01-01

    Temporal changes in the Earth’s magnetic field, known as geomagnetic secular variation, occur most prominently at low latitudes in the Atlantic hemisphere1, 2 (that is, from −90 degrees east to 90 degrees east), whereas in the Pacific hemisphere there is comparatively little activity. This is a c......Temporal changes in the Earth’s magnetic field, known as geomagnetic secular variation, occur most prominently at low latitudes in the Atlantic hemisphere1, 2 (that is, from −90 degrees east to 90 degrees east), whereas in the Pacific hemisphere there is comparatively little activity....... This is a consequence of the geographical localization of intense, westward drifting, equatorial magnetic flux patches at the core surface3. Despite successes in explaining the morphology of the geomagnetic field4, numerical models of the geodynamo have so far failed to account systematically for this striking pattern...... of geomagnetic secular variation. Here we show that it can be reproduced provided that two mechanisms relying on the inner core are jointly considered. First, gravitational coupling5 aligns the inner core with the mantle, forcing the flow of liquid metal in the outer core into a giant, westward drifting, sheet...

  8. The Early Anthropogenic Hypothesis: Top-Down and Bottom-up Evidence

    Science.gov (United States)

    Ruddiman, W. F.

    2014-12-01

    Two complementary lines of evidence support the early anthropogenic hypothesis. Top-down evidence comes from comparing Holocene greenhouse-gas trends with those during equivalent intervals of previous interglaciations. The increases in CO2 and CH4 during the late Holocene are anomalous compared to the decreasing trends in a stacked average of previous interglaciations, thereby supporting an anthropogenic origin. During interglacial stage 19, the closest Holocene insolation analog, CO2 fell to 245 ppm by the time equivalent to the present, in contrast to the observed pre-industrial rise to 280-285 ppm. The 245-ppm level measured in stage 19 falls at the top of the natural range predicted by the original anthropogenic hypothesis of Ruddiman (2003). Bottom-up evidence comes from a growing list of archeological and other compilations showing major early anthropogenic transformations of Earth's surface. Key examples include: efforts by Dorian Fuller and colleagues mapping the spread of irrigated rice agriculture across southern Asia and its effects on CH4 emissions prior to the industrial era; an additional effort by Fuller showing the spread of methane-emitting domesticated livestock across Asia and Africa (coincident with the spread of fertile crescent livestock across Europe); historical compilations by Jed Kaplan and colleagues documenting very high early per-capita forest clearance in Europe, thus underpinning simulations of extensive pre-industrial clearance and large CO2 emissions; and wide-ranging studies by Erle Ellis and colleagues of early anthropogenic land transformations in China and elsewhere.

  9. Top-down silicon microcantilever with coupled bottom-up silicon nanowire for enhanced mass resolution

    International Nuclear Information System (INIS)

    A stepped cantilever composed of a bottom-up silicon nanowire coupled to a top-down silicon microcantilever electrostatically actuated and with capacitive or optical readout is fabricated and analyzed, both theoretically and experimentally, for mass sensing applications. The mass sensitivity at the nanowire free end and the frequency resolution considering thermomechanical noise are computed for different nanowire dimensions. The results obtained show that the coupled structure presents a very good mass sensitivity thanks to the nanowire, where the mass depositions take place, while also presenting a very good frequency resolution due to the microcantilever, where the transduction is carried out. A two-fold improvement in mass sensitivity with respect to that of the microcantilever standalone is experimentally demonstrated, and at least an order-of-magnitude improvement is theoretically predicted, only changing the nanowire length. Very close frequency resolutions are experimentally measured and theoretically predicted for a standalone microcantilever and for a microcantilever-nanowire coupled system. Thus, an improvement in mass sensing resolution of the microcantilever-nanowire stepped cantilever is demonstrated with respect to that of the microcantilever standalone. (paper)

  10. Optical and electronic properties study of bottom-up graphene nanoribbons for photovoltaic applications

    Science.gov (United States)

    Villegas, Cesar E. P.; Rocha, Alexandre

    2015-03-01

    Graphene nanoribbons (GNRs), turn out to be serious contender for several optolectronic applications due to their physical properties. Recently, bottom-up methods, using the assembly of appropriate precursor molecules were shown to be an exciting pathway towards making precise nanoribbons. In particular, it has been demonstrated that so-called cove-shaped GNRs absorb light in the visible part of the spectrum, suggesting they could be used for photovoltaic applications. In solar cells, the key ingredient is the presence excitons and their subsequent diffusion along a donor material. This is influenced by the character of the different excitations taking place, as well as, the exciton binding energy. Thus, In this work we use many-body corrected density functional theory to simulate the optical properties of these nanoribbons. We elucidate the most important transitions occurring in these systems, and identify types of excitatiions that have not been previously observed in conventional nanoribbons. We also find that the exciton binding energies for all the structures we considered are in the eV range, which enhances the diffusion lengths for the particle-hole pairs. Finally, we estimate the potencial of these systems as solar cells by calculating the short-circuit current. The Authors thank FAPESP for financial support.

  11. Bottom-Up, Wet Chemical Technique for the Continuous Synthesis of Inorganic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Annika Betke

    2014-01-01

    Full Text Available Continuous wet chemical approaches for the production of inorganic nanoparticles are important for large scale production of nanoparticles. Here we describe a bottom-up, wet chemical method applying a microjet reactor. This technique allows the separation between nucleation and growth in a continuous reactor environment. Zinc oxide (ZnO, magnetite (Fe3O4, as well as brushite (CaHPO4·2H2O, particles with a small particle size distribution can be obtained continuously by using the rapid mixing of two precursor solutions and the fast removal of the nuclei from the reaction environment. The final particles were characterized by FT-IR, TGA, DLS, XRD and SEM techniques. Systematic studies on the influence of the different process parameters, such as flow rate and process temperature, show that the particle size can be influenced. Zinc oxide was obtained with particle sizes between 44 nm and 102 nm. The obtained magnetite particles have particle sizes in the range of 46 nm to 132 nm. Brushite behaves differently; the obtained particles were shaped like small plates with edge lengths between 100 nm and 500 nm.

  12. Top-Down Network Analysis to Drive Bottom-Up Modeling of Physiological Processes

    Science.gov (United States)

    Poirel, Christopher L.; Rodrigues, Richard R.; Chen, Katherine C.; Tyson, John J.

    2013-01-01

    Abstract Top-down analyses in systems biology can automatically find correlations among genes and proteins in large-scale datasets. However, it is often difficult to design experiments from these results. In contrast, bottom-up approaches painstakingly craft detailed models that can be simulated computationally to suggest wet lab experiments. However, developing the models is a manual process that can take many years. These approaches have largely been developed independently. We present Linker, an efficient and automated data-driven method that can analyze molecular interactomes to propose extensions to models that can be simulated. Linker combines teleporting random walks and k-shortest path computations to discover connections from a source protein to a set of proteins collectively involved in a particular cellular process. We evaluate the efficacy of Linker by applying it to a well-known dynamic model of the cell division cycle in Saccharomyces cerevisiae. Compared to other state-of-the-art methods, subnetworks computed by Linker are heavily enriched in Gene Ontology (GO) terms relevant to the cell cycle. Finally, we highlight how networks computed by Linker elucidate the role of a protein kinase (Cdc5) in the mitotic exit network of a dynamic model of the cell cycle. PMID:23641868

  13. Achieving integrated urban water management: planning top-down or bottom-up?

    Science.gov (United States)

    Gabe, J; Trowsdale, S; Vale, R

    2009-01-01

    Integrated Urban Water Management (IUWM) acknowledges a broad range of environmental and socio-economic outcomes but the link between design intentions and operational performance is not always clear. This may be due in part to a lack of shared principles that remove bias and inconsistency in assessing the operational performance of IUWM. This paper investigates the possibility of developing shared principles through examination of shared objectives and shared indicators within two logical and integrated frameworks for urban residential developments that aspire for IUWM and sustainable development. The framework method was applied using very different approaches-one a top-down urban planning process, the other a bottom-up community consultation process. Both frameworks highlight the extent to which IUWM is part of a broad social and environmental system. Core environmental performance objectives and indicators were very similar, highlighting the potential to develop shared principles in reporting and benchmarking the environmental performance of neighbourhood developments. Socio-economic indicators were highly variable due to process and likely contextual differences, thus it is unclear if the influence of IUWM on these variables can transcend the social context unless the practice of urban water management can expand its core responsibility beyond "hard" physical infrastructure. PMID:19474495

  14. Evidence for differential top-down and bottom-up suppression in posterior parietal cortex.

    Science.gov (United States)

    Mirpour, Koorosh; Bisley, James W

    2013-10-19

    When searching for an object, we usually avoid items that are visually different from the target and objects or places that have been searched already. Previous studies have shown that neural activity in the lateral intraparietal area (LIP) can be used to guide this behaviour; responses to task irrelevant stimuli or to stimuli that have been fixated previously in the trial are reduced compared with responses to potential targets. Here, we test the hypothesis that these reduced responses have a different genesis. Two animals were trained on a visual foraging task, in which they had to find a target among a number of physically identical potential targets (T) and task irrelevant distractors. We recorded neural activity and local field potentials (LFPs) in LIP while the animals performed the task. We found that LFP power was similar for potential targets and distractors but was greater in the alpha and low beta bands when a previously fixated T was in the response field. We interpret these data to suggest that the reduced single-unit response to distractors is a bottom-up feed-forward result of processing in earlier areas and the reduced response to previously fixated Ts is a result of active top-down suppression. PMID:24018730

  15. Bottom-up and top-down mechanisms indirectly mediate interactions between benthic biotic ecosystem components

    Science.gov (United States)

    Van Colen, Carl; Thrush, Simon F.; Parkes, Samantha; Harris, Rachel; Woodin, Sally A.; Wethey, David S.; Pilditch, Conrad A.; Hewitt, Judi E.; Lohrer, Andrew M.; Vincx, Magda

    2015-04-01

    The loss or decline in population size of key species can instigate a cascade of effects that have implications for interacting species, therewith impacting biodiversity and ecosystem functioning. We examined how top-down and bottom-up interactions may mediate knock-on effects of a coastal deposit-feeding clam, Macomona liliana (hereafter Macomona), on sandflat meiobenthos densities. Therefore we manipulated densities of Macomona in combination with predator exclusion and experimental shading that was expected to alter microphytobenthos biomass. We show that Macomona regulated densities of meiobenthic (38-500 μm) nematodes, copepods, polychaetes, turbellarians, and ostracodes during the three months of incubation via indirect mechanisms. Predator pressure on Macomona by eagle rays (Myliobatis tenuicaudatus) was found to have a negative effect on densities of some meiobenthic taxa. Furthermore, experimental shading resulted in the loss of a positive relation between Macomona and microphytobenthos biomass, while concurrently increasing the density of some meiobenthic taxa. We suggest that this observation can be explained by the release from bioturbation interference effects of the cockle Austrovenus stutchburyi that was found to thrive in the presence of Macomona under non-shaded conditions. Our results highlight the importance of interactions between macrofaunal bioturbation, microphyte biomass, sediment stability, and predation pressure for the structuring of benthic communities. This experiment illustrates that manipulative field experiments may be particularly suitable to study such multiple indirect mechanisms that regulate ecosystem diversity and related functioning because such approaches may best capture the complex feedbacks and processes that determine ecosystem dynamics.

  16. Template-Free Bottom-Up Method for Fabricating Diblock Copolymer Patchy Particles.

    Science.gov (United States)

    Ye, Xianggui; Li, Zhan-Wei; Sun, Zhao-Yan; Khomami, Bamin

    2016-05-24

    Patchy particles are one of most important building blocks for hierarchical structures because of the discrete patches on their surface. We have demonstrated a convenient, simple, and scalable bottom-up method for fabricating diblock copolymer patchy particles through both experiments and dissipative particle dynamics (DPD) simulations. The experimental method simply involves reducing the solvent quality of the diblock copolymer solution by the slow addition of a nonsolvent. Specifically, the fabrication of diblock copolymer patchy particles begins with a crew-cut soft-core micelle, where the micelle core is significantly swelled by the solvent. With water addition at an extremely slow rate, the crew-cut soft-core micelles first form a larger crew-cut micelle. With further water addition, the corona-forming blocks of the crew-cut micelles begin to aggregate and eventually form well-defined patches. Both experiments and DPD simulations indicate that the number of patches has a very strong dependence on the diblock copolymer composition-the particle has more patches on the surface with a lower volume fraction of patch-forming blocks. Furthermore, particles with more patches have a greater ability to assemble, and particles with fewer patches have a greater ability to merge once assembled. PMID:27109249

  17. Bottom-up study of flaw tolerance properties of protein networks

    Science.gov (United States)

    Qin, Zhao; Buehler, Markus

    2012-02-01

    We study the material properties of an intermediate filament proten network by computational modeling using a bottom-up approach. We start with an atomic model of each filament's and obtain the mechanical behavior of them. We then use these parameters in setting up a mesoscale model of the network material at scales of micrometers. Using this multi-scale method, we report a detailed analysis of the associated deformation and failure mechanisms of this hierarchical material. Our modeling reveals that a structure transition that occurs at the proteins' secondary structure level is crucial for the networks' flaw tolerance property, which implies that the material retains its mechanical function despite the existence of large defects. We also examine the effect of crosslink strength on the failure properties. We discover that relatively weaker crosslinks lead to a more flaw tolerant network that is 23% stronger. This unexpected behavior is caused by that the crosslink strength functions as a switch to alter the failure mechanism. Weak crosslinks are able to efficiently diffuse the stress around the crack tip, making the crack more difficult to propagate. We compare our results to that of elastic and softening materials and find that the effect of crosslink strength is much smaller in those systems. These findings imply that the mechanical properties of both the filaments and interfaces among filaments are critical for bioinspired material designs, challenging the conventional paradigm in engineering design.

  18. Bottom-Up Abstract Modelling of Optical Networks-on-Chip: From Physical to Architectural Layer

    Directory of Open Access Journals (Sweden)

    Alberto Parini

    2012-01-01

    Full Text Available This work presents a bottom-up abstraction procedure based on the design-flow FDTD + SystemC suitable for the modelling of optical Networks-on-Chip. In this procedure, a complex network is decomposed into elementary switching elements whose input-output behavior is described by means of scattering parameters models. The parameters of each elementary block are then determined through 2D-FDTD simulation, and the resulting analytical models are exported within functional blocks in SystemC environment. The inherent modularity and scalability of the S-matrix formalism are preserved inside SystemC, thus allowing the incremental composition and successive characterization of complex topologies typically out of reach for full-vectorial electromagnetic simulators. The consistency of the outlined approach is verified, in the first instance, by performing a SystemC analysis of a four-input, four-output ports switch and making a comparison with the results of 2D-FDTD simulations of the same device. Finally, a further complex network encompassing 160 microrings is investigated, the losses over each routing path are calculated, and the minimum amount of power needed to guarantee an assigned BER is determined. This work is a basic step in the direction of an automatic technology-aware network-level simulation framework capable of assembling complex optical switching fabrics, while at the same time assessing the practical feasibility and effectiveness at the physical/technological level.

  19. Ursgal, Universal Python Module Combining Common Bottom-Up Proteomics Tools for Large-Scale Analysis.

    Science.gov (United States)

    Kremer, Lukas P M; Leufken, Johannes; Oyunchimeg, Purevdulam; Schulze, Stefan; Fufezan, Christian

    2016-03-01

    Proteomics data integration has become a broad field with a variety of programs offering innovative algorithms to analyze increasing amounts of data. Unfortunately, this software diversity leads to many problems as soon as the data is analyzed using more than one algorithm for the same task. Although it was shown that the combination of multiple peptide identification algorithms yields more robust results, it is only recently that unified approaches are emerging; however, workflows that, for example, aim to optimize search parameters or that employ cascaded style searches can only be made accessible if data analysis becomes not only unified but also and most importantly scriptable. Here we introduce Ursgal, a Python interface to many commonly used bottom-up proteomics tools and to additional auxiliary programs. Complex workflows can thus be composed using the Python scripting language using a few lines of code. Ursgal is easily extensible, and we have made several database search engines (X!Tandem, OMSSA, MS-GF+, Myrimatch, MS Amanda), statistical postprocessing algorithms (qvality, Percolator), and one algorithm that combines statistically postprocessed outputs from multiple search engines ("combined FDR") accessible as an interface in Python. Furthermore, we have implemented a new algorithm ("combined PEP") that combines multiple search engines employing elements of "combined FDR", PeptideShaker, and Bayes' theorem. PMID:26709623

  20. Bottom-Up Visual Saliency Estimation With Deep Autoencoder-Based Sparse Reconstruction.

    Science.gov (United States)

    Xia, Chen; Qi, Fei; Shi, Guangming

    2016-06-01

    Research on visual perception indicates that the human visual system is sensitive to center-surround (C-S) contrast in the bottom-up saliency-driven attention process. Different from the traditional contrast computation of feature difference, models based on reconstruction have emerged to estimate saliency by starting from original images themselves instead of seeking for certain ad hoc features. However, in the existing reconstruction-based methods, the reconstruction parameters of each area are calculated independently without taking their global correlation into account. In this paper, inspired by the powerful feature learning and data reconstruction ability of deep autoencoders, we construct a deep C-S inference network and train it with the data sampled randomly from the entire image to obtain a unified reconstruction pattern for the current image. In this way, global competition in sampling and learning processes can be integrated into the nonlocal reconstruction and saliency estimation of each pixel, which can achieve better detection results than the models with separate consideration on local and global rarity. Moreover, by learning from the current scene, the proposed model can achieve the feature extraction and interaction simultaneously in an adaptive way, which can form a better generalization ability to handle more types of stimuli. Experimental results show that in accordance with different inputs, the network can learn distinct basic features for saliency modeling in its code layer. Furthermore, in a comprehensive evaluation on several benchmark data sets, the proposed method can outperform the existing state-of-the-art algorithms. PMID:26800552

  1. Visionmaker NYC: A bottom-up approach to finding shared socioeconomic pathways in New York City

    Science.gov (United States)

    Sanderson, E. W.; Fisher, K.; Giampieri, M.; Barr, J.; Meixler, M.; Allred, S. B.; Bunting-Howarth, K. E.; DuBois, B.; Parris, A. S.

    2015-12-01

    Visionmaker NYC is a free, public participatory, bottom-up web application to develop and share climate mitigation and adaptation strategies for New York City neighborhoods. The goal is to develop shared socioeconomic pathways by allowing a broad swath of community members - from schoolchildren to architects and developers to the general public - to input their concepts for a desired future. Visions are comprised of climate scenarios, lifestyle choices, and ecosystem arrangements, where ecosystems are broadly defined to include built ecosystems (e.g. apartment buildings, single family homes, etc.), transportation infrastructure (e.g. highways, connector roads, sidewalks), and natural land cover types (e.g. wetlands, forests, estuary.) Metrics of water flows, carbon cycling, biodiversity patterns, and population are estimated for the user's vision, for the same neighborhood today, and for that neighborhood as it existed in the pre-development state, based on the Welikia Project (welikia.org.) Users can keep visions private, share them with self-defined groups of other users, or distribute them publicly. Users can also propose "challenges" - specific desired states of metrics for specific parts of the city - and others can post visions in response. Visionmaker contributes by combining scenario planning, scientific modelling, and social media to create new, wide-open possibilities for discussion, collaboration, and imagination regarding future, shared socioeconomic pathways.

  2. A Computational Strategy to Analyze Label-Free Temporal Bottom-up Proteomics Data

    Energy Technology Data Exchange (ETDEWEB)

    Du, Xiuxia; Callister, Stephen J.; Manes, Nathan P.; Adkins, Joshua N.; Alexandridis, Roxana A.; Zeng, Xiaohua; Roh, Jung Hyeob; Smith, William E.; Donohue, Timothy J.; Kaplan, Samuel; Smith, Richard D.; Lipton, Mary S.

    2008-07-01

    Motivation: Biological systems are in a continual state of flux, which necessitates an understanding of the dynamic nature of protein abundances. The study of protein abundance dynamics has become feasible with recent improvements in mass spectrometry-based quantitative proteomics. However, a number of challenges still re-main related to how best to extract biological information from dy-namic proteomics data; for example, challenges related to extrane-ous variability, missing abundance values, and the identification of significant temporal patterns. Results: This article describes a strategy that addresses the afore-mentioned issues for the analysis of temporal bottom-up proteomics data. The core strategy for the data analysis algorithms and subse-quent data interpretation was formulated to take advantage of the temporal properties of the data. The analysis procedure presented herein was applied to data from a Rhodobacter sphaeroides 2.4.1 time-course study. The results were in close agreement with existing knowledge about R. sphaeroides, therefore demonstrating the utility of this analytical strategy.

  3. Bottom-up synthesis of ordered metal/oxide/metal nanodots on substrates for nanoscale resistive switching memory

    Science.gov (United States)

    Han, Un-Bin; Lee, Jang-Sik

    2016-05-01

    The bottom-up approach using self-assembled materials/processes is thought to be a promising solution for next-generation device fabrication, but it is often found to be not feasible for use in real device fabrication. Here, we report a feasible and versatile way to fabricate high-density, nanoscale memory devices by direct bottom-up filling of memory elements. An ordered array of metal/oxide/metal (copper/copper oxide/copper) nanodots was synthesized with a uniform size and thickness defined by self-organized nanotemplate mask by sequential electrochemical deposition (ECD) of each layer. The fabricated memory devices showed bipolar resistive switching behaviors confirmed by conductive atomic force microscopy. This study demonstrates that ECD with bottom-up growth has great potential to fabricate high-density nanoelectronic devices beyond the scaling limit of top-down device fabrication processes.

  4. Bottom-up synthesis of ordered metal/oxide/metal nanodots on substrates for nanoscale resistive switching memory

    Science.gov (United States)

    Han, Un-Bin; Lee, Jang-Sik

    2016-01-01

    The bottom-up approach using self-assembled materials/processes is thought to be a promising solution for next-generation device fabrication, but it is often found to be not feasible for use in real device fabrication. Here, we report a feasible and versatile way to fabricate high-density, nanoscale memory devices by direct bottom-up filling of memory elements. An ordered array of metal/oxide/metal (copper/copper oxide/copper) nanodots was synthesized with a uniform size and thickness defined by self-organized nanotemplate mask by sequential electrochemical deposition (ECD) of each layer. The fabricated memory devices showed bipolar resistive switching behaviors confirmed by conductive atomic force microscopy. This study demonstrates that ECD with bottom-up growth has great potential to fabricate high-density nanoelectronic devices beyond the scaling limit of top-down device fabrication processes. PMID:27157385

  5. The Comparative Effect of Top-down Processing and Bottom-up Processing through TBLT on Extrovert and Introvert EFL

    Directory of Open Access Journals (Sweden)

    Pezhman Nourzad Haradasht

    2013-09-01

    Full Text Available This research seeks to examine the effect of two models of reading comprehension, namely top-down and bottom-up processing, on the reading comprehension of extrovert and introvert EFL learners’ reading comprehension. To do this, 120 learners out of a total number of 170 intermediate learners being educated at Iran Mehr English Language School were selected all taking a PET (Preliminary English Test first for homogenization prior to the study. They also answered the Eysenck Personality Inventory (EPI which in turn categorized them into two subgroups within each reading models consisting of introverts and extroverts. All in all, there were four subgroups: 30 introverts and 30 extroverts undergoing the top-down processing treatment, and 30 introverts and 30 extroverts experiencing the bottom-up processing treatment. The aforementioned PET was administered as the post test of the study after each group was exposed to the treatment for 18 sessions in six weeks. After the instructions finished, the mean scores of all four groups on this post test were computed and a two-way ANOVA was run to test all the four hypotheses raise in this study. the results showed that while learners generally benefitted more from the bottom-up processing setting compared  to the top-down processing one, the extrovert group was better off receiving top-down instruction. Furthermore, introverts outperformed extroverts in bottom-up group; yet between the two personalities subgroups in the top-down setting no difference was seen. A predictable pattern of benefitting from teaching procedures could not be drawn for introverts as in both top-down and bottom-up settings, they benefitted more than extroverts.Keywords: Reading comprehension, top-down processing, bottom-up processing, extrovert, introvert

  6. OBJCUT: efficient segmentation using top-down and bottom-up cues.

    Science.gov (United States)

    Kumar, M Pawan; Torr, P H S; Zisserman, A

    2010-03-01

    We present a probabilistic method for segmenting instances of a particular object category within an image. Our approach overcomes the deficiencies of previous segmentation techniques based on traditional grid conditional random fields (CRF), namely that 1) they require the user to provide seed pixels for the foreground and the background and 2) they provide a poor prior for specific shapes due to the small neighborhood size of grid CRF. Specifically, we automatically obtain the pose of the object in a given image instead of relying on manual interaction. Furthermore, we employ a probabilistic model which includes shape potentials for the object to incorporate top-down information that is global across the image, in addition to the grid clique potentials which provide the bottom-up information used in previous approaches. The shape potentials are provided by the pose of the object obtained using an object category model. We represent articulated object categories using a novel layered pictorial structures model. Nonarticulated object categories are modeled using a set of exemplars. These object category models have the advantage that they can handle large intraclass shape, appearance, and spatial variation. We develop an efficient method, OBJCUT, to obtain segmentations using our probabilistic framework. Novel aspects of this method include: 1) efficient algorithms for sampling the object category models of our choice and 2) the observation that a sampling-based approximation of the expected log-likelihood of the model can be increased by a single graph cut. Results are presented on several articulated (e.g., animals) and nonarticulated (e.g., fruits) object categories. We provide a favorable comparison of our method with the state of the art in object category specific image segmentation, specifically the methods of Leibe and Schiele and Schoenemann and Cremers. PMID:20075476

  7. Top-down or bottom-up: Contrasting perspectives on psychiatric diagnoses

    Directory of Open Access Journals (Sweden)

    Willem MA Verhoeven

    2008-09-01

    Full Text Available Willem MA Verhoeven1,2, Siegfried Tuinier1, Ineke van der Burgt31Vincent van Gogh Institute for Psychiatry, Venray, The Netherlands; 2Department of Psychiatry, Erasmus University Medical Centre, Rotterdam, The Netherlands; 3Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The NetherlandsAbstract: Clinical psychiatry is confronted with the expanding knowledge of medical genetics. Most of the research into the genetic underpinnings of major mental disorders as described in the categorical taxonomies, however, did reveal linkage with a variety of chromosomes. This heterogeneity of results is most probably due to the assumption that the nosological categories as used in these studies are disease entities with clear boundaries. If the reverse way of looking, the so-called bottom-up approach, is applied, it becomes clear that genetic abnormalities are in most cases not associated with a single psychiatric disorder but with a certain probability to develop a variety of aspecific psychiatric symptoms. The adequacy of the categorical taxonomy, the so-called top-down approach, seems to be inversely related to the amount of empirical etiological data. This is illustrated by four rather prevalent genetic syndromes, fragile X syndrome, Prader-Willi syndrome, 22q11 deletion syndrome, and Noonan syndrome, as well as by some cases with rare chromosomal abnormalities. From these examples, it becomes clear that psychotic symptoms as well as mood, anxiety, and autistic features can be found in a great variety of different genetic syndromes. A psychiatric phenotype exists, but comprises, apart from the chance to present several psychiatric symptoms, all elements from developmental, neurocognitive, and physical characteristics.Keywords: genetic disorders, psychiatric symptoms, phenotype, mental disorders

  8. Grain size engineering of bcc refractory metals: Top-down and bottom-up-Application to tungsten

    International Nuclear Information System (INIS)

    We have used two general methodologies for the production of ultrafine grained (UFG) and nanocrystalline (NC) tungsten (W) metal samples: top-down and bottom-up. In the first, Equal channel angular extrusion (ECAE), coupled with warm rolling has been used to fabricate UFG W, and high pressure torsion (HPT) was used to fabricate NC W. We demonstrate an abrupt shift in the deformation mechanism, particularly under dynamic compressive loading, in UFG and NC W. This novel deformation mechanism, a dramatic transition from a uniform deformation mode to that of localized shearing, is shared by other UFG and NC body-centerd cubic (BCC) metals. We have also conducted a series of bottom-up experiments to consolidate powdered UFG W precursors into solid bodies. The bottom-up approach relies on rapid, high-temperature consolidation, specifically designed for UFG and NC W powders. The mechanical property results from the top-down UFG and NC W were used as minimum property benchmarks to guide and design the experimental protocols and parameters for use in the bottom-up procedures. Preliminary results, showing rapid grain growth during the consolidation cycle, did not achieve full density in the W samples. Further development of high-purity W nanopowders and appropriate grain-growth inhibitors (e.g., Zener pinning) will be required to successfully produce bulk-sized UFG and NC W samples

  9. Leadership for Quality University Teaching: How Bottom-Up Academic Insights Can Inform Top-Down Leadership

    Science.gov (United States)

    Scott, Donald E.; Scott, Shelleyann

    2016-01-01

    This paper presents the leadership implications from a study that explored how to increase the quality of teaching in a university thereby presenting data from the bottom up--the academic perspective--to inform leadership, policies, and academic development which generally flows from the top down. We report academics' perceptions of and…

  10. Addressing a "Black Box" of Bottom-Up Synthesis: Revealing the Structures of Growing Colloidal-Nanocrystal Nuclei.

    Science.gov (United States)

    Sobol, Oded; Gadot, Eyal; Wang, Yifeng; Weinstock, Ira A; Meshi, Louisa

    2015-11-16

    In bottom-up synthesis, products from reactions of structural building units rapidly pass from soluble molecular complexes to nanoscale intermediates, whose solution-state structures defy elucidation by any routine method. To address this, electron diffraction is used to reveal the structures of cryogenically "trapped" colloidal nanocrystals. PMID:26536393

  11. The Roles of Feature-Specific Task Set and Bottom-Up Salience in Attentional Capture: An ERP Study

    Science.gov (United States)

    Eimer, Martin; Kiss, Monika; Press, Clare; Sauter, Disa

    2009-01-01

    We investigated the roles of top-down task set and bottom-up stimulus salience for feature-specific attentional capture. Spatially nonpredictive cues preceded search arrays that included a color-defined target. For target-color singleton cues, behavioral spatial cueing effects were accompanied by cue-induced N2pc components, indicative of…

  12. Assessing the Gap Between Top-down and Bottom-up Measured Methane Emissions in Indianapolis, IN.

    Science.gov (United States)

    Prasad, K.; Lamb, B. K.; Cambaliza, M. O. L.; Shepson, P. B.; Stirm, B. H.; Salmon, O. E.; Lavoie, T. N.; Lauvaux, T.; Ferrara, T.; Howard, T.; Edburg, S. L.; Whetstone, J. R.

    2014-12-01

    Releases of methane (CH4) from the natural gas supply chain in the United States account for approximately 30% of the total US CH4 emissions. However, there continues to be large questions regarding the accuracy of current emission inventories for methane emissions from natural gas usage. In this paper, we describe results from top-down and bottom-up measurements of methane emissions from the large isolated city of Indianapolis. The top-down results are based on aircraft mass balance and tower based inverse modeling methods, while the bottom-up results are based on direct component sampling at metering and regulating stations, surface enclosure measurements of surveyed pipeline leaks, and tracer/modeling methods for other urban sources. Mobile mapping of methane urban concentrations was also used to identify significant sources and to show an urban-wide low level enhancement of methane levels. The residual difference between top-down and bottom-up measured emissions is large and cannot be fully explained in terms of the uncertainties in top-down and bottom-up emission measurements and estimates. Thus, the residual appears to be, at least partly, attributed to a significant wide-spread diffusive source. Analyses are included to estimate the size and nature of this diffusive source.

  13. Motivation and drives in bottom-up developments in natural hazards management: multiple-use of adaptation strategies in Austria

    Science.gov (United States)

    Thaler, Thomas; Fuchs, Sven

    2015-04-01

    Losses from extreme hydrological events, such as recently experienced in Europe have focused the attention of policymakers as well as researchers on vulnerability to natural hazards. In parallel, the context of changing flood risks under climate and societal change is driving transformation in the role of the state in responsibility sharing and individual responsibilities for risk management and precaution. The new policy agenda enhances the responsibilities of local authorities and private citizens in hazard management and reduces the role of central governments. Within the objective is to place added responsibility on local organisations and citizens to determine locally-based strategies for risk reduction. A major challenge of modelling adaptation is to represent the complexity of coupled human-environmental systems and particularly the feedback loops between environmental dynamics and human decision-making processes on different scales. This paper focuses on bottom-up initiatives to flood risk management which are, by definition, different from the mainstream. These initiatives are clearly influenced (positively or negatively) by a number of factors, where the combination of these interdependences can create specific conditions that alter the opportunity for effective governance arrangements in a local scheme approach. In total, this study identified six general drivers which encourage the implementation of flood storages, such as direct relation to recent major flood frequency and history, the initiative of individual stakeholders (promoters), political pressures from outside (e.g. business companies, private households) and a strong solidarity attitude of municipalities and the stakeholders involved. Although partnership approach may be seen as an 'optimal' solution for flood risk management, in practice there are many limitations and barriers in establishing these collaborations and making them effective (especially in the long term) with the consequences

  14. Reconciling Top-Down and Bottom-Up Estimates of Oil and Gas Methane Emissions in the Barnett Shale

    Science.gov (United States)

    Hamburg, S.

    2015-12-01

    Top-down approaches that use aircraft, tower, or satellite-based measurements of well-mixed air to quantify regional methane emissions have typically estimated higher emissions from the natural gas supply chain when compared to bottom-up inventories. A coordinated research campaign in October 2013 used simultaneous top-down and bottom-up approaches to quantify total and fossil methane emissions in the Barnett Shale region of Texas. Research teams have published individual results including aircraft mass-balance estimates of regional emissions and a bottom-up, 25-county region spatially-resolved inventory. This work synthesizes data from the campaign to directly compare top-down and bottom-up estimates. A new analytical approach uses statistical estimators to integrate facility emission rate distributions from unbiased and targeted high emission site datasets, which more rigorously incorporates the fat-tail of skewed distributions to estimate regional emissions of well pads, compressor stations, and processing plants. The updated spatially-resolved inventory was used to estimate total and fossil methane emissions from spatial domains that match seven individual aircraft mass balance flights. Source apportionment of top-down emissions between fossil and biogenic methane was corroborated with two independent analyses of methane and ethane ratios. Reconciling top-down and bottom-up estimates of fossil methane emissions leads to more accurate assessment of natural gas supply chain emission rates and the relative contribution of high emission sites. These results increase our confidence in our understanding of the climate impacts of natural gas relative to more carbon-intensive fossil fuels and the potential effectiveness of mitigation strategies.

  15. A bottom-up approach to urban metabolism: the perspective of BRIDGE

    Science.gov (United States)

    Chrysoulakis, N.; Borrego, C.; San Josè, R.; Grimmond, S. B.; Jones, M. B.; Magliulo, V.; Klostermann, J.; Santamouris, M.

    2011-12-01

    Urban metabolism considers a city as a system and usually distinguishes between energy and material flows as its components. "Metabolic" studies are usually top-down approaches that assess the inputs and outputs of food, water, energy, and pollutants from a city, or that compare the changing metabolic process of several cities. In contrast, bottom-up approaches are based on quantitative estimates of urban metabolism components at local to regional scales. Such approaches consider the urban metabolism as the 3D exchange and transformation of energy and matter between a city and its environment. The city is considered as a system and the physical flows between this system and its environment are quantitatively estimated. The transformation of landscapes from primarily agricultural and forest uses to urbanized landscapes can greatly modify energy and material exchanges and it is, therefore, an important aspect of an urban area. Here we focus on the exchanges and transformation of energy, water, carbon and pollutants. Recent advances in bio-physical sciences have led to new methods and models to estimate local scale energy, water, carbon and pollutant fluxes. However, there is often poor communication of new knowledge and its implications to end-users, such as planners, architects and engineers. The FP7 Project BRIDGE (SustainaBle uRban plannIng Decision support accountinG for urban mEtabolism) aims at bridging this gap and at illustrating the advantages of considering environmental issues in urban planning. BRIDGE does not perform a complete life cycle analysis or calculate whole system urban metabolism, but rather focuses on specific metabolism components (energy, water, carbon and pollutants). Its main goal is the development of a Decision Suport System (DSS) with the potential to select planning actions which better fit the goal of changing the metabolism of urban systems towards sustainability. BRIDGE evaluates how planning alternatives can modify the physical

  16. 自底向上的应用层组播树重构算法%Bottom-Up Application Layer Multicast Tree Reconstruction Algorithm

    Institute of Scientific and Technical Information of China (English)

    邓正伟; 李锋

    2011-01-01

    Based on the analysis of the traditional application layer multicast tree reconstruction algorithm, combined with proactive reconstruction technique, a bottom-up application layer multicast tree reconstruction algorithm is proposed. The algorithm employs a bottom-up strategy, which combines both local and global-selection strategies for backup parent node choice. Simulation results show that the algorithm has improvement in the respect of recovery delay of multicast tree, the quality of the reconstructed tree and the control overhead of tree reconstruction.%分析传统应用层组播树重构算法的不足,结合前向式重构技术,提出一种自底向上的应用层组播树重构算法.采用自底向上的方法将备用父节点的本地选择策略和全局选择策略进行有机结合.仿真结果表明,该算法在组播树的恢复时延、重构树的质量、树重建的控制开销方面都有一定的改进.

  17. Price elasticities, policy measures and actual developments in household energy consumption - A bottom up analysis for the Netherlands

    International Nuclear Information System (INIS)

    In the Netherlands it seems likely that the large number of new policy measures in the past decade has influenced the response of households to changing prices. To investigate this issue the energy trends in the period 1990-2000 have been simulated with a bottom-up model, applied earlier for scenario studies, and extensive data from surveys. For a number of alternative price cases the elasticity values found are explained using the bottom-up changes in energy trends. One finding is that the specific set of saving options defines for a great part the price response. The price effect has been analysed too in combination with the policy measures standards, subsidies and energy taxes. The simulation results indicate that the elasticity value could be 30-40% higher without these measures. (author)

  18. Robust aircraft segmentation from very high-resolution images based on bottom-up and top-down cue integration

    Science.gov (United States)

    Gao, Feng; Xu, Qizhi; Li, Bo

    2016-01-01

    Existing segmentation methods require manual interventions to optimally extract objects from cluttered background, so that they can hardly work well in automated surveillance systems. In order to automatically extract aircrafts from very high-resolution images, we proposed a segmentation method that combines bottom-up and top-down cues. Three essential principles from local contrast, global contrast, and center bias are involved to compute bottom-up cue. In addition, top-down cue is computed by incorporating aircraft shape priors, and it is achieved by training a classifier from a rich set of visual features. Iterative operations and adaptive fitting are designed to get refined results. Experimental results demonstrated that the proposed method can provide significant improvements on the segmentation accuracy.

  19. Tisza, Transmission and Innovation: An Innovative Bottom-up Model for Transmission and Promotion of Tisza Cultural Heritage

    OpenAIRE

    Barberis Rami, Matías Ezequiel; Berić, Dejan; Mátai, Anikó; Opriş, Lavinia-Ioana; Ricci, Giulia; Rustja, Dritan

    2015-01-01

    The project aims to promote and preserve both tangible and intangible cultural heritage in a particular region of the Danube river basin, Tisza Region (TR). The TR cultural heritage is less-well-known in the rest of Europe and is at risk of being lost or forgotten if not preserved and supported. In this project is presented an innovative and strategic bottom-up model which allows local people to manage how their heritage is disseminated through transmission and promotion of their ...

  20. Top-down but not bottom-up visual scanning is affected in hereditary pure cerebellar ataxia.

    Directory of Open Access Journals (Sweden)

    Shunichi Matsuda

    Full Text Available The aim of this study was to clarify the nature of visual processing deficits caused by cerebellar disorders. We studied the performance of two types of visual search (top-down visual scanning and bottom-up visual scanning in 18 patients with pure cerebellar types of spinocerebellar degeneration (SCA6: 11; SCA31: 7. The gaze fixation position was recorded with an eye-tracking device while the subjects performed two visual search tasks in which they looked for a target Landolt figure among distractors. In the serial search task, the target was similar to the distractors and the subject had to search for the target by processing each item with top-down visual scanning. In the pop-out search task, the target and distractor were clearly discernible and the visual salience of the target allowed the subjects to detect it by bottom-up visual scanning. The saliency maps clearly showed that the serial search task required top-down visual attention and the pop-out search task required bottom-up visual attention. In the serial search task, the search time to detect the target was significantly longer in SCA patients than in normal subjects, whereas the search time in the pop-out search task was comparable between the two groups. These findings suggested that SCA patients cannot efficiently scan a target using a top-down attentional process, whereas scanning with a bottom-up attentional process is not affected. In the serial search task, the amplitude of saccades was significantly smaller in SCA patients than in normal subjects. The variability of saccade amplitude (saccadic dysmetria, number of re-fixations, and unstable fixation (nystagmus were larger in SCA patients than in normal subjects, accounting for a substantial proportion of scattered fixations around the items. Saccadic dysmetria, re-fixation, and nystagmus may play important roles in the impaired top-down visual scanning in SCA, hampering precise visual processing of individual items.

  1. The Comparative Effect of Top-down Processing and Bottom-up Processing through TBLT on Extrovert and Introvert EFL

    OpenAIRE

    Pezhman Nourzad Haradasht; Abdollah Baradaran

    2013-01-01

    This research seeks to examine the effect of two models of reading comprehension, namely top-down and bottom-up processing, on the reading comprehension of extrovert and introvert EFL learners’ reading comprehension. To do this, 120 learners out of a total number of 170 intermediate learners being educated at Iran Mehr English Language School were selected all taking a PET (Preliminary English Test) first for homogenization prior to the study. They also answered the Eysenck Personality Invent...

  2. Community context mediates the top-down vs. bottom-up effects of grazers on rocky shores

    OpenAIRE

    Bracken, MES; Dolecal, RE; Long, JD

    2014-01-01

    Interactions between grazers and autotrophs are complex, including both topdown consumptive and bottom-up facilitative effects of grazers. Thus, in addition to consuming autotrophs, herbivores can also enhance autotroph biomass by recycling limiting nutrients, thereby increasing nutrient availability. Here, we evaluated these consumptive and facilitative interactions between snails (Littorina littorea) and seaweeds (Fucus vesiculosus and Ulva lactuca) on a rocky shore. We partitioned herbivor...

  3. Radiographic Evaluation of Children with Febrile Urinary Tract Infection: Bottom-Up, Top-Down, or None of the Above?

    OpenAIRE

    Prasad, Michaella M.; Cheng, Earl Y.

    2011-01-01

    The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI) is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS), voiding cystourethrogram (VCUG), and dimercapto-succinic acid (DMSA) scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (no...

  4. An integrated top-down and bottom-up proteomic approach to characterize the antigen binding fragment of antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, Leendert J.; Wu, Si; vanDuijn, Martijn M.; Tolic, Nikola; Stingl, Christoph; Zhao, Rui; Luider, Theo N.; Pasa-Tolic, Ljiljana

    2014-05-31

    We have previously shown that different individuals exposed to the same antigen produce antibodies with identical mutations in their complementarity determining regions (CDR), suggesting that CDR tryptic peptides can serve as biomarkers for disease diagnosis and prognosis. Complete Fabs derived from disease specific antibodies have even higher potential; they could potentially be used for disease treatment and are required to identify the antigens towards which the antibodies are directed. However, complete Fab sequence characterization via LC-MS analysis of tryptic peptides (i.e. bottom-up) has proven to be impractical for mixtures of antibodies. To tackle this challenge, we have developed an integrated bottom-up and top-down MS approach, employing 2D chromatography coupled with Fourier transform mass spectrometry (FTMS), and applied this approach for full characterization of the variable parts of two pharmaceutical monoclonal antibodies with sensitivity comparable to the bottom-up standard. These efforts represent an essential step towards the identification of disease specific antibodies in patient samples with potentially significant clinical impact.

  5. A comprehensive estimate of recent carbon sinks in China using both top-down and bottom-up approaches

    Science.gov (United States)

    Jiang, Fei; Chen, Jing; Zhou, Linxi; Ju, Weimin; Zhang, Huifang; Machida, Toshinobu; Ciais, Philippe; Peters, Wouter; Wang, Hengmao; Chen, Baozhang; Liu, Linxin; Zhang, Chunhua; Matsueda, Hidekazu; Sawa, Yousuke

    2016-04-01

    Atmospheric inversions use measurements of atmospheric CO2 gradients to constrain regional surface fluxes. Current inversions indicate a net terrestrial CO2 sink in China between 0.16 and 0.35 PgC/yr. The uncertainty of these estimates is as large as the mean because the atmospheric network historically contained only one high altitude station in China. Here, we revisit the calculation of the terrestrial CO2 flux in China, excluding emissions from fossil fuel burning and cement production, by using two inversions with three new CO2 monitoring stations in China as well as aircraft observations over Asia. We estimate a net terrestrial CO2 uptake of 0.39-0.51 PgC/yr with a mean of 0.45 PgC/yr in 2006-2009. After considering the lateral transport of carbon in air and water and international trade, the annual mean carbon sink is adjusted to 0.35 PgC/yr. To evaluate this top-down estimate, we constructed an independent bottom-up estimate based on ecosystem data, and giving a net land sink of 0.33 PgC/yr. This demonstrates closure between the top-down and bottom-up estimates. Both top-down and bottom-up estimates give a higher carbon sink than previous estimates made for the 1980s and 1990s, suggesting a trend towards increased uptake by land ecosystems in China.

  6. A comprehensive estimate of recent carbon sinks in China using both top-down and bottom-up approaches

    Science.gov (United States)

    Jiang, Fei; Chen, Jing M.; Zhou, Lingxi; Ju, Weimin; Zhang, Huifang; Machida, Toshinobu; Ciais, Philippe; Peters, Wouter; Wang, Hengmao; Chen, Baozhang; Liu, Lixin; Zhang, Chunhua; Matsueda, Hidekazu; Sawa, Yousuke

    2016-02-01

    Atmospheric inversions use measurements of atmospheric CO2 gradients to constrain regional surface fluxes. Current inversions indicate a net terrestrial CO2 sink in China between 0.16 and 0.35 PgC/yr. The uncertainty of these estimates is as large as the mean because the atmospheric network historically contained only one high altitude station in China. Here, we revisit the calculation of the terrestrial CO2 flux in China, excluding emissions from fossil fuel burning and cement production, by using two inversions with three new CO2 monitoring stations in China as well as aircraft observations over Asia. We estimate a net terrestrial CO2 uptake of 0.39-0.51 PgC/yr with a mean of 0.45 PgC/yr in 2006-2009. After considering the lateral transport of carbon in air and water and international trade, the annual mean carbon sink is adjusted to 0.35 PgC/yr. To evaluate this top-down estimate, we constructed an independent bottom-up estimate based on ecosystem data, and giving a net land sink of 0.33 PgC/yr. This demonstrates closure between the top-down and bottom-up estimates. Both top-down and bottom-up estimates give a higher carbon sink than previous estimates made for the 1980s and 1990s, suggesting a trend towards increased uptake by land ecosystems in China.

  7. Bottom-up effects of nutrient availability on flower production, pollinator visitation, and seed output in a high-Andean shrub.

    Science.gov (United States)

    Muñoz, Alejandro A; Celedon-Neghme, Constanza; Cavieres, Lohengrin A; Arroyo, Mary T K

    2005-03-01

    Soil nutrient availability directly enhances vegetative growth, flowering, and fruiting in alpine ecosystems. However, the impacts of nutrient addition on pollinator visitation, which could affect seed output indirectly, are unknown. In a nutrient addition experiment, we tested the hypothesis that seed output in the insect-pollinated, self-incompatible shrub, Chuquiraga oppositifolia (Asteraceae) of the Andes of central Chile, is enhanced by soil nitrogen (N) availability. We aimed to monitor total shrub floral display, size of flower heads (capitula), pollinator visitation patterns, and seed output during three growing seasons on control and N addition shrubs. N addition did not augment floral display, size of capitula, pollinator visitation, or seed output during the first growing season. Seed mass and viability were 25-40% lower in fertilised shrubs. During the second growing season only 33% of the N addition shrubs flowered compared to 71% of controls, and a significant (50%) enhancement in vegetative growth occurred in fertilised shrubs. During the third growing season, floral display in N addition shrubs was more than double that of controls, received more than twice the number of insect pollinator visits, and seed output was three- to four-fold higher compared to controls. A significant (50%) enhancement in vegetative growth again occurred in N addition shrubs. Results of this study strongly suggest that soil N availability produces strong positive bottom-up effects on the reproductive output of the alpine shrub C. oppositifolia. Despite taking considerably longer to be manifest in comparison to the previously reported top-down indirect negative effects of lizard predators in the same study system, our results suggest that both bottom-up and top-down forces are important in controlling the reproductive output of an alpine shrub. PMID:15583940

  8. Parallel- and serial-contact electrochemical metallization of monolayer nanopatterns: A versatile synthetic tool en route to bottom-up assembly of electric nanocircuits

    Directory of Open Access Journals (Sweden)

    Jonathan Berson

    2012-02-01

    Full Text Available Contact electrochemical transfer of silver from a metal-film stamp (parallel process or a metal-coated scanning probe (serial process is demonstrated to allow site-selective metallization of monolayer template patterns of any desired shape and size created by constructive nanolithography. The precise nanoscale control of metal delivery to predefined surface sites, achieved as a result of the selective affinity of the monolayer template for electrochemically generated metal ions, provides a versatile synthetic tool en route to the bottom-up assembly of electric nanocircuits. These findings offer direct experimental support to the view that, in electrochemical metal deposition, charge is carried across the electrode–solution interface by ion migration to the electrode rather than by electron transfer to hydrated ions in solution.

  9. Bottom-up processing of thermoelectric nanocomposites from colloidal nanocrystal building blocks: the case of Ag{sub 2}Te-PbTe

    Energy Technology Data Exchange (ETDEWEB)

    Cadavid, Doris [Catalonia Institute for Energy Research, IREC (Spain); Ibanez, Maria [Universitat de Barcelona, Departament d' Electronica (Spain); Gorsse, Stephane [Universite de Bordeaux, ICMCB, CNRS (France); Lopez, Antonio M. [Universitat Politecnica de Catalunya, Departament d' Enginyeria Electronica (Spain); Cirera, Albert [Universitat de Barcelona, Departament d' Electronica (Spain); Morante, Joan Ramon; Cabot, Andreu, E-mail: acabot@irec.cat [Catalonia Institute for Energy Research, IREC (Spain)

    2012-12-15

    Nanocomposites are highly promising materials to enhance the efficiency of current thermoelectric devices. A straightforward and at the same time highly versatile and controllable approach to produce nanocomposites is the assembly of solution-processed nanocrystal building blocks. The convenience of this bottom-up approach to produce nanocomposites with homogeneous phase distributions and adjustable composition is demonstrated here by blending Ag{sub 2}Te and PbTe colloidal nanocrystals to form Ag{sub 2}Te-PbTe bulk nanocomposites. The thermoelectric properties of these nanocomposites are analyzed in the temperature range from 300 to 700 K. The evolution of their electrical conductivity and Seebeck coefficient is discussed in terms of the blend composition and the characteristics of the constituent materials.

  10. HCFC-142b emissions in China: An inventory for 2000 to 2050 basing on bottom-up and top-down methods

    Science.gov (United States)

    Han, Jiarui; Li, Li; Su, Shenshen; Hu, Jianxin; Wu, Jing; Wu, Yusheng; Fang, Xuekun

    2014-05-01

    1-Chloro-1,1-difluoroethane (HCFC-142b) is both ozone depleting substance included in the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) and potent greenhouse gas with high global warming potential. As one of the major HCFC-142b consumption and production countries in the world, China's control action will contribute to both mitigating climate change and protecting ozone layer. Estimating China's HCFC-142b emission is a crucial step for understanding its emission status, drawing up phasing-out plan and evaluating mitigation effect. Both the bottom-up and top-down method were adopted in this research to estimate HCFC-142b emissions from China. Results basing on different methods were compared to test the effectiveness of two methods and validate inventory's reliability. Firstly, a national bottom-up emission inventory of HCFC-142b for China during 2000-2012 was established based on the 2006 IPCC Guidelines for National Greenhouse Gas Inventories and the Montreal Protocol, showing that in contrast to the downward trend revealed by existing results, HCFC-142b emissions kept increasing from 0.1 kt/yr in 2000 to the peak of 14.4 kt/yr in 2012. Meanwhile a top-down emission estimation was also developed using interspecies correlation method. By correlating atmospheric mixing ratio data of HCFC-142b and reference substance HCFC-22 sampled from four representative cities (Beijing, Hangzhou, Lanzhou and Guangzhou, for northern, eastern, western and southern China, respectively), China's HCFC-142b emission in 2012 was calculated. It was 16.24(13.90-18.58) kt, equivalent to 1.06 kt ODP and 37 Tg CO2-eq, taking up 9.78% (ODP) of total HCFCs emission in China or 30.5% of global HCFC-142b emission. This result was 12.7% higher than that in bottom-up inventory. Possible explanations were discussed. The consistency of two results lend credit to methods effectiveness and results reliability. Finally, future HCFC-142b emission was projected to 2050

  11. "Disorganized in time": impact of bottom-up and top-down negative emotion generation on memory formation among healthy and traumatized adolescents.

    Science.gov (United States)

    Guillery-Girard, Bérengère; Clochon, Patrice; Giffard, Bénédicte; Viard, Armelle; Egler, Pierre-Jean; Baleyte, Jean-Marc; Eustache, Francis; Dayan, Jacques

    2013-09-01

    "Travelling in time," a central feature of episodic memory is severely affected among individuals with Post Traumatic Stress Disorder (PTSD) with two opposite effects: vivid traumatic memories are unorganized in temporality (bottom-up processes), non-traumatic personal memories tend to lack spatio-temporal details and false recognitions occur more frequently that in the general population (top-down processes). To test the effect of these two types of processes (i.e. bottom-up and top-down) on emotional memory, we conducted two studies in healthy and traumatized adolescents, a period of life in which vulnerability to emotion is particularly high. Using negative and neutral images selected from the international affective picture system (IAPS), stimuli were divided into perceptual images (emotion generated by perceptual details) and conceptual images (emotion generated by the general meaning of the material). Both categories of stimuli were then used, along with neutral pictures, in a memory task with two phases (encoding and recognition). In both populations, we reported a differential effect of the emotional material on encoding and recognition. Negative perceptual scenes induced an attentional capture effect during encoding and enhanced the recollective distinctiveness. Conversely, the encoding of conceptual scenes was similar to neutral ones, but the conceptual relatedness induced false memories at retrieval. However, among individuals with PTSD, two subgroups of patients were identified. The first subgroup processed the scenes faster than controls, except for the perceptual scenes, and obtained similar performances to controls in the recognition task. The second subgroup group desmonstrated an attentional deficit in the encoding task with no benefit from the distinctiveness associated with negative perceptual scenes on memory performances. These findings provide a new perspective on how negative emotional information may have opposite influences on memory in

  12. Bottom-up coarse-grained models that accurately describe the structure, pressure, and compressibility of molecular liquids

    International Nuclear Information System (INIS)

    The present work investigates the capability of bottom-up coarse-graining (CG) methods for accurately modeling both structural and thermodynamic properties of all-atom (AA) models for molecular liquids. In particular, we consider 1, 2, and 3-site CG models for heptane, as well as 1 and 3-site CG models for toluene. For each model, we employ the multiscale coarse-graining method to determine interaction potentials that optimally approximate the configuration dependence of the many-body potential of mean force (PMF). We employ a previously developed “pressure-matching” variational principle to determine a volume-dependent contribution to the potential, UV(V), that approximates the volume-dependence of the PMF. We demonstrate that the resulting CG models describe AA density fluctuations with qualitative, but not quantitative, accuracy. Accordingly, we develop a self-consistent approach for further optimizing UV, such that the CG models accurately reproduce the equilibrium density, compressibility, and average pressure of the AA models, although the CG models still significantly underestimate the atomic pressure fluctuations. Additionally, by comparing this array of models that accurately describe the structure and thermodynamic pressure of heptane and toluene at a range of different resolutions, we investigate the impact of bottom-up coarse-graining upon thermodynamic properties. In particular, we demonstrate that UV accounts for the reduced cohesion in the CG models. Finally, we observe that bottom-up coarse-graining introduces subtle correlations between the resolution, the cohesive energy density, and the “simplicity” of the model

  13. Benchmarking energy scenarios for China: perspectives from top-down, economic and bottom-up, technical modelling

    DEFF Research Database (Denmark)

    This study uses a soft-linking methodology to harmonise two complex global top-down and bottom-up models with a regional China focus. The baseline follows the GDP and demographic trends of the Shared Socio-economic Pathways (SSP2) scenario, down-scaled for China, while the carbon tax scenario fol......-specific modelling results further. These new sub-regional China features can now be used for a more detailed analysis of China's regional developments in a global context....

  14. Top-down and Bottom-up. Testing a mixed approach to the generation of priorities for sustainable urban mobility

    OpenAIRE

    E. Pieralice; F. Mameli; G. Marletto

    2015-01-01

    This paper contributes to the debate on how to make operational the concept of sustainable urban mobility and advocates the use of a mixed – top-down and bottom-up – approach to the generation of priorities for sustainable urban mobility. In particular, we tested whether a common list of priorities remain valid after a participated scrutiny performed in seven urban areas of southern Italy. The test was based on a 3-steps procedure. In step 1, we used a common conceptual framework (based on Ma...

  15. Bottom-up modelling of continuous renovation and energy balance of existing building stock: case study Kočevje

    OpenAIRE

    Šijanec Zavrl, Marjana; Stegnar, Gašper; Rakušček, Andraž; Gjerkeš, Henrik

    2016-01-01

    A dynamic bottom-up model of the building stock is developed and implemented in a case study of Kočevje urban region. In the model, national register of real estate is cross-linked to data from other registers, e.g. the energy performance certificates (EPC) and the subsidized energy renovation measures. Regular updates of the data in registers enable continual improvement of the model. Therenovation potential is determined with respect to the age of building components after the last renovati...

  16. Bottom-Up Nano-heteroepitaxy of Wafer-Scale Semipolar GaN on (001) Si

    KAUST Repository

    Hus, Jui Wei

    2015-07-15

    Semipolar {101¯1} InGaN quantum wells are grown on (001) Si substrates with an Al-free buffer and wafer-scale uniformity. The novel structure is achieved by a bottom-up nano-heteroepitaxy employing self-organized ZnO nanorods as the strain-relieving layer. This ZnO nanostructure unlocks the problems encountered by the conventional AlN-based buffer, which grows slowly and contaminates the growth chamber. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Land claim settlements and their impacts : regional dynamics and bottom-up economic development in Nunavik and Nunatsiavut (Canada)

    OpenAIRE

    Fugmann, Gerlis

    2011-01-01

    Since the 1970s, land claim and self-government agreements have provided the Inuit in the Arctic with a variety of tools, granting them considerable rights and benefits within their traditional settlement areas. One of the central purposes of these regional agreements was to create an economic base in order to enhance development from within the various regions and thus promote economic self-reliance for the Inuit beneficiaries. This bottom-up approach is a clear shift from the top-down devel...

  18. A bottom-up approach for optimization of friction stir processing parameters; a study on aluminium 2024-T3 alloy

    International Nuclear Information System (INIS)

    Highlights: • An experimental bottom-up approach has been developed for optimizing the process parameters for friction stir processing. • Optimum parameter processed samples were tested and characterized in detail. • Ultimate tensile strength of 1.3 times the base metal strength was obtained. • Residual stresses on the processed surface were only 10% of the yield strength of base metal. • Microstructure observations revealed fine equi-axed grains with precipitate particles at the grain boundaries. - Abstract: Friction stir processing (FSP) is emerging as one of the most competent severe plastic deformation (SPD) method for producing bulk ultra-fine grained materials with improved properties. Optimizing the process parameters for a defect free process is one of the challenging aspects of FSP to mark its commercial use. For the commercial aluminium alloy 2024-T3 plate of 6 mm thickness, a bottom-up approach has been attempted to optimize major independent parameters of the process such as plunge depth, tool rotation speed and traverse speed. Tensile properties of the optimum friction stir processed sample were correlated with the microstructural characterization done using Scanning Electron Microscope (SEM) and Electron Back-Scattered Diffraction (EBSD). Optimum parameters from the bottom-up approach have led to a defect free FSP having a maximum strength of 93% the base material strength. Micro tensile testing of the samples taken from the center of processed zone has shown an increased strength of 1.3 times the base material. Measured maximum longitudinal residual stress on the processed surface was only 30 MPa which was attributed to the solid state nature of FSP. Microstructural observation reveals significant grain refinement with less variation in the grain size across the thickness and a large amount of grain boundary precipitation compared to the base metal. The proposed experimental bottom-up approach can be applied as an effective method for

  19. Benchmarking energy scenarios for China: perspectives from top-down, economic and bottom-up, technical modelling

    OpenAIRE

    Mischke, Peggy

    2014-01-01

    This study uses a soft-linking methodology to harmonise two complex global top-down and bottom-up models with a regional China focus. The baseline follows the GDP and demographic trends of the Shared Socio-economic Pathways (SSP2) scenario, down-scaled for China, while the carbon tax scenario follows the pathway of the Asia Modelling Exercise.We find that soft-linking allows "bridging the gap" and reducing uncertainty between these models. Without soft-linking, baseline result ranges for Chin...

  20. The drastic outcomes from voting alliances in three-party bottom-up democratic voting (1990 $\\rightarrow$ 2013)

    OpenAIRE

    Galam, Serge

    2013-01-01

    The drastic effect of local alliances in three-party competition is investigated in democratic hierarchical bottom-up voting. The results are obtained analytically using a model which extends a sociophysics frame introduced in 1986 \\cite{psy} and 1990 \\cite{lebo} to study two-party systems and the spontaneous formation of democratic dictatorship. It is worth stressing that the 1990 paper was published in the Journal of Statistical Physics, the first paper of its kind in the journal. It was sh...

  1. Una implementación computacional de un modelo de atención visual Bottom-up aplicado a escenas naturales/A Computational Implementation of a Bottom-up Visual Attention Model Applied to Natural Scenes

    Directory of Open Access Journals (Sweden)

    Juan F. Ramírez Villegas

    2011-12-01

    Full Text Available El modelo de atención visual bottom-up propuesto por Itti et al., 2000 [1], ha sido un modelo popular en tanto exhibe cierta evidencia neurobiológica de la visión en primates. Este trabajo complementa el modelo computacional de este fenómeno desde la dinámica realista de una red neuronal. Asimismo, esta aproximación se basa en la existencia de mapas topográficos que representan la prominencia de los objetos del campo visual para la formación de una representación general (mapa de prominencia, esta representación es la entrada de una red neuronal dinámica con interacciones locales y globales de colaboración y competencia que convergen sobre las principales particularidades (objetos de la escena.The bottom-up visual attention model proposed by Itti et al. 2000 [1], has been a popular model since it exhibits certain neurobiological evidence of primates’ vision. This work complements the computational model of this phenomenon using a neural network with realistic dynamics. This approximation is based on several topographical maps representing the objects saliency that construct a general representation (saliency map, which is the input for a dynamic neural network, whose local and global collaborative and competitive interactions converge to the main particularities (objects presented by the visual scene as well.

  2. Chitosan microspheres with an extracellular matrix-mimicking nanofibrous structure as cell-carrier building blocks for bottom-up cartilage tissue engineering

    Science.gov (United States)

    Zhou, Yong; Gao, Huai-Ling; Shen, Li-Li; Pan, Zhao; Mao, Li-Bo; Wu, Tao; He, Jia-Cai; Zou, Duo-Hong; Zhang, Zhi-Yuan; Yu, Shu-Hong

    2015-12-01

    Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation. Recently, as a valuable alternative, a bottom-up TE approach utilizing cell-loaded micrometer-scale modular components as building blocks to reconstruct a new tissue in vitro or in vivo has been proved to demonstrate a number of desirable advantages compared with the traditional bulk scaffold based top-down TE approach. Nevertheless, micro-components with an ECM-mimicking nanofibrous structure are still very scarce and highly desirable. Chitosan (CS), an accessible natural polymer, has demonstrated appealing intrinsic properties and promising application potential for TE, especially the cartilage tissue regeneration. According to this background, we report here the fabrication of chitosan microspheres with an ECM-mimicking nanofibrous structure for the first time based on a physical gelation process. By combining this physical fabrication procedure with microfluidic technology, uniform CS microspheres (CMS) with controlled nanofibrous microstructure and tunable sizes can be facilely obtained. Especially, no potentially toxic or denaturizing chemical crosslinking agent was introduced into the products. Notably, in vitro chondrocyte culture tests revealed that enhanced cell attachment and proliferation were realized, and a macroscopic 3D geometrically shaped cartilage-like composite can be easily constructed with the nanofibrous CMS (NCMS) and chondrocytes, which demonstrate significant application potential of NCMS as the bottom-up cell-carrier components for cartilage tissue engineering.Scaffolds for tissue engineering (TE) which closely mimic the physicochemical properties of the natural extracellular matrix (ECM) have been proven to advantageously favor cell attachment, proliferation, migration and new tissue formation

  3. Impaired Bottom-Up Effective Connectivity Between Amygdala and Subgenual Anterior Cingulate Cortex in Unmedicated Adolescents with Major Depression: Results from a Dynamic Causal Modeling Analysis.

    Science.gov (United States)

    Musgrove, Donald R; Eberly, Lynn E; Klimes-Dougan, Bonnie; Basgoze, Zeynep; Thomas, Kathleen M; Mueller, Bryon A; Houri, Alaa; Lim, Kelvin O; Cullen, Kathryn R

    2015-12-01

    Major depressive disorder (MDD) is a significant contributor to lifetime disability and frequently emerges in adolescence, yet little is known about the neural mechanisms of MDD in adolescents. Dynamic causal modeling (DCM) analysis is an innovative tool that can shed light on neural network abnormalities. A DCM analysis was conducted to test several frontolimbic effective connectivity models in 27 adolescents with MDD and 21 healthy adolescents. The best neural model for each person was identified using Bayesian model selection. The findings revealed that the two adolescent groups fit similar optimal neural models. The best across-groups model was then used to infer upon both within-group and between-group tests of intrinsic and modulation parameters of the network connections. First, for model validation, within-group tests revealed robust evidence for bottom-up connectivity, but less evidence for strong top-down connectivity in both groups. Second, we tested for differences between groups on the validated parameters of the best model. This revealed that adolescents with MDD had significantly weaker bottom-up connectivity in one pathway, from amygdala to sgACC (p=0.008), than healthy controls. This study provides the first examination of effective connectivity using DCM within neural circuitry implicated in emotion processing in adolescents with MDD. These findings aid in advancing understanding the neurobiology of early-onset MDD during adolescence and have implications for future research investigating how effective connectivity changes across contexts, with development, over the course of the disease, and after intervention. PMID:26050933

  4. An activity-based energy demand modeling framework for buildings: A bottom-up approach

    OpenAIRE

    Subbiah, Rajesh

    2013-01-01

    Energy consumption by buildings, due to various factors such as temperature regulation, lighting, poses a threat to our environment and energy resources. In the United States, statistics reveal that commercial and residential buildings combined contribute about 40 percent of the overall energy consumption, and this figure is expected to increase. In order to manage the growing demand for energy, there is a need for energy system optimization, which would require a realistic, high-resolution e...

  5. Source attribution of methane emissions from global oil and gas production: results of bottom-up simulations over three decades

    Science.gov (United States)

    Höglund-Isaksson, Lena

    2016-04-01

    Existing bottom-up emission inventories of historical methane and ethane emissions from global oil and gas systems do not well explain year-on-year variations estimated by top-down models from atmospheric measurements. This paper develops a bottom-up methodology which allows for country- and year specific source attribution of methane and ethane emissions from global oil and natural gas production for the period 1980 to 2012. The analysis rests on country-specific simulations of associated gas flows which are converted into methane and ethane emissions. The associated gas flows are constructed from country-specific information on oil and gas production and associated gas generation and recovery, and coupled with generic assumptions to bridge regional information gaps on the fractions of unrecovered associated gas that is vented instead of flared. Summing up emissions from associated gas flows with global estimates of emissions from unintended leakage and natural gas transmission and distribution, the resulting global emissions of methane and ethane from oil and gas systems are reasonably consistent with corresponding estimates from top-down models. Also revealed is that the fall of the Soviet Union in 1990 had a significant impact on methane and ethane emissions from global oil and gas systems.

  6. Thousand and one ways to quantify and compare protein abundances in label-free bottom-up proteomics.

    Science.gov (United States)

    Blein-Nicolas, Mélisande; Zivy, Michel

    2016-08-01

    How to process and analyze MS data to quantify and statistically compare protein abundances in bottom-up proteomics has been an open debate for nearly fifteen years. Two main approaches are generally used: the first is based on spectral data generated during the process of identification (e.g. peptide counting, spectral counting), while the second makes use of extracted ion currents to quantify chromatographic peaks and infer protein abundances based on peptide quantification. These two approaches actually refer to multiple methods which have been developed during the last decade, but were submitted to deep evaluations only recently. In this paper, we compiled these different methods as exhaustively as possible. We also summarized the way they address the different problems raised by bottom-up protein quantification such as normalization, the presence of shared peptides, unequal peptide measurability and missing data. This article is part of a Special Issue entitled: Plant Proteomics- a bridge between fundamental processes and crop production, edited by Dr. Hans-Peter Mock. PMID:26947242

  7. Bottom-up and top-down solid-state NMR approaches for bacterial biofilm matrix composition

    Science.gov (United States)

    Cegelski, Lynette

    2015-04-01

    The genomics and proteomics revolutions have been enormously successful in providing crucial "parts lists" for biological systems. Yet, formidable challenges exist in generating complete descriptions of how the parts function and assemble into macromolecular complexes and whole-cell assemblies. Bacterial biofilms are complex multicellular bacterial communities protected by a slime-like extracellular matrix that confers protection to environmental stress and enhances resistance to antibiotics and host defenses. As a non-crystalline, insoluble, heterogeneous assembly, the biofilm extracellular matrix poses a challenge to compositional analysis by conventional methods. In this perspective, bottom-up and top-down solid-state NMR approaches are described for defining chemical composition in complex macrosystems. The "sum-of-the-parts" bottom-up approach was introduced to examine the amyloid-integrated biofilms formed by Escherichia coli and permitted the first determination of the composition of the intact extracellular matrix from a bacterial biofilm. An alternative top-down approach was developed to define composition in Vibrio cholerae biofilms and relied on an extensive panel of NMR measurements to tease out specific carbon pools from a single sample of the intact extracellular matrix. These two approaches are widely applicable to other heterogeneous assemblies. For bacterial biofilms, quantitative parameters of matrix composition are needed to understand how biofilms are assembled, to improve the development of biofilm inhibitors, and to dissect inhibitor modes of action. Solid-state NMR approaches will also be invaluable in obtaining parameters of matrix architecture.

  8. Galvanostatic bottom-up filling of TSV-like trenches: Choline-based leveler containing two quaternary ammoniums

    International Nuclear Information System (INIS)

    Highlights: • The choline-based leveler having two quaternary ammoniums was synthesized. • The adsorption of this leveler with suppressor and accelerator was examined. • Galvanostatic Cu bottom-up filling was achieved with three-additive system. • The mechanism of gap-filling was elucidated based on the additive adsorption. - Abstract: Through Silicon Via (TSV) technology is essential to accomplish 3-dimensional packaging of electronics. Hence, more reliable and faster TSV filling by Cu electrodeposition is required. Our approach to improve Cu gap-filling in TSV is based on the development of new organic additives for feature filling. Here, we introduce our achievements from the synthesis of choline-based leveler to the feature filling using a synthesized leveler. The choline-based leveler, which includes two quaternary ammoniums at both ends of the molecule, is synthesized from glutaric acid. The characteristics of the choline-based additive are examined by the electrochemical analyses, and it is confirmed that the choline-based leveler shows a convection dependent adsorption behavior, which is essential for leveling. The interactions between the polymeric suppressor, accelerator, and the choline-based leveler are also investigated by changing the convection condition. Using the combination of suppressor, accelerator, and the choline-based leveler, the extreme bottom-up filling of Cu at trenches with dimensions similar to TSV are fulfilled. The mechanism of Cu gap-filling is demonstrated based on the results of electrochemical analyses and feature filling

  9. The drastic outcomes from voting alliances in three-party bottom-up democratic voting (1990 $\\rightarrow$ 2013)

    CERN Document Server

    Galam, Serge

    2013-01-01

    The drastic effect of local alliances in three-party competition is investigated in democratic hierarchical bottom-up voting. The results are obtained analytically using a model which extends a sociophysics frame introduced in 1986 \\cite{psy} and 1990 \\cite{lebo} to study two-party systems and the spontaneous formation of democratic dictatorship. It is worth stressing that the 1990 paper was published in the Journal of Statistical Physics, the first paper of its kind in the journal. It was shown how a minority in power can preserve its leadership using bottom-up democratic elections. However such a bias holds only down to some critical value of minimum support. The results were used latter to explain the sudden collapse of European communist parties in the nineties. The extension to three-party competition reveals the mechanisms by which a very small minority party can get a substantial representation at higher levels of the hierarchy when the other two competing parties are big. Additional surprising results...

  10. Bottom-up effects of climate on fish populations: data from the Continuous Plankton Recorder

    DEFF Research Database (Denmark)

    Pitois, S.G.; Lynam, C.P.; Jansen, Teunis;

    2012-01-01

    unique opportunity to investigate long-term changes over decadal scales in the abundance and distribution of fish larvae in relation to physical and biological factors. A principal component analysis (PCA) using 7 biotic and abiotic parameters is applied to investigate the impact of environmental changes......) impacting on the hydro dynamic features of the North Sea, in turn impacting on the plankton available as prey for fish larvae. The responses and adaptability of fish larvae to changing environmental conditions, parti cularly to changes in prey availability, are complex and species-specific. This complexity...

  11. Directed self-assembly of nanorod networks: bringing the top down to the bottom up

    International Nuclear Information System (INIS)

    Self-assembled electrodeposited nanorod materials have been shown to offer an exciting landscape for a wide array of research ranging from nanophotonics through to biosensing and magnetics. However, until now, the scope for site-specific preparation of the nanorods on wafers has been limited to local area definition. Further there is little or no lateral control of nanorod height. In this work we present a scalable method for controlling the growth of the nanorods in the vertical direction as well as their lateral position. A focused ion beam pre-patterns the Au cathode layer prior to the creation of the anodized aluminium oxide (AAO) template on top. When the pre-patterning is of the same dimension as the pore spacing of the AAO template, lines of single nanorods are successfully grown. Further, for sub-200 nm wide features, a relationship between the nanorod height and distance from the non-patterned cathode can be seen to follow a quadratic growth rate obeying Faraday’s law of electrodeposition. This facilitates lateral control of nanorod height combined with localized growth of the nanorods. (paper)

  12. Organizing and financing interstellar space projects - A bottom-up approach

    CERN Document Server

    Ceyssens, Frederik; Wouters, Kristof; Ceyssens, Pieter-Jan; Wen, Lianggong

    2011-01-01

    The development and deployment of interstellar missions will without doubt require orders of magnitude more resources than needed for current or past megaprojects (Apollo, Iter, LHC,...). Question is how enough resources for such gigaprojects can be found. In this contribution different scenarios will be explored assuming limited, moderate economic growth throughout the next centuries, i.e. without human population and productivity continuing to grow exponentially, and without extreme events such as economic collapse or singularity. In such a world, which is not unlike the current situation, gigascale space projects face a combination of inhibiting factors: the enormous cost threshold, the need for risky and costly development of often quite application specific technology, the relatively little benefit with respect to the costs for the sponsors, the time span of at least a few generations and the absence of a sense of urgency. It will be argued that the best chance of getting an interstellar project started ...

  13. Mineralization of Synthetic Polymer Scaffolds: A Bottom-upApproach for the Development of Artificial Bone

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jie; Viengkham, Malathong; Bertozzi, Carolyn R.

    2004-09-27

    The controlled integration of organic and inorganic components confers natural bone with superior mechanical properties. Bone biogenesis is thought to occur by templated mineralization of hard apatite crystals by an elastic protein scaffold, a process we sought to emulate with synthetic biomimetic hydrogel polymers. Crosslinked polymethacrylamide and polymethacrylate hydrogels were functionalized with mineral-binding ligands and used to template the formation of hydroxyapatite. Strong adhesion between the organic and inorganic materials was achieved for hydrogels functionalized with either carboxylate or hydroxy ligands. The mineral-nucleating potential of hydroxyl groups identified here broadens the design parameters for synthetic bone-like composites and suggests a potential role for hydroxylated collagen proteins in bone mineralization.

  14. Carbon balance: the top-down and bottom-up emissions accounting methodologies; Balanco de carbono: a contabilidade das emissoes nas metodologias 'Top-Down' estendida ('Top-Bottom') e 'Bottom-Up'

    Energy Technology Data Exchange (ETDEWEB)

    Alvim, Carlos Feu; Eidelman, Frida; Ferreira, Omar Campos

    2005-08-15

    The Economy and Energy Organization has carried out together with the Ministry of Science and Technology a study on the carbon balance of energy use and transformation. The publication of its results has been made through the e and e periodical in its 48 and 50 issues. In the present issue we are publishing the results corresponding to the extended Top-Down accounting process and those corresponding to the use of the coefficients calculated for the Brazilian inventory from 1990 to 1994, using the Bottom-Up process, to estimate the emissions from 1970 to 2002. By comparing the two results it is possible to evaluate their deficiencies and the possible incoherence in the use of the two methodologies. (author)

  15. Regression analysis for a bottom-up approach to analyzing semi-prompt fission gamma yields

    International Nuclear Information System (INIS)

    Highlights: ► Fitting the semi-prompt non-resolved photon spectrum after fission. ► Energy–time dependence can be factorized. ► Physical model, statistical model, sampling procedure. ► The best fit is: lognormal for energy and F for time. - Abstract: We present an empirical model that describes the yield of gamma rays emitted by fission in the time interval from 20 to 958 ns following a fission event. The analysis is based on experimental data from neutron-induced fission of 235U and 239Pu. The model is devised by first using regression analysis to identify likely patterns in the data and to choose plausible fitting functions. We provide statistical and physical arguments in support of time and energy independence. The intensity of the emitted gamma rays can be described as a bivariate distribution that is the product of independent variates for energy and time. We test several plausible distribution families for the energy and time variates and use maximum likelihood and minimum χ2 to estimate distribution parameters. Because of the uncertainty in the experimental data, multiple combinations of variate pairs give rise to a surface that plausibly well fits the observations well. The best-fit variate turns out to be lognormal in energy and F in time. The findings illustrated in this paper can be used to simulate gamma ray de-excitation from fission in Monte Carlo codes.

  16. A Volunteered Geographic Information Framework to Enable Bottom-Up Disaster Management Platforms

    Directory of Open Access Journals (Sweden)

    Mohammad Ebrahim Poorazizi

    2015-08-01

    Full Text Available Recent disasters, such as the 2010 Haiti earthquake, have drawn attention to the potential role of citizens as active information producers. By using location-aware devices such as smartphones to collect geographic information in the form of geo-tagged text, photos, or videos, and sharing this information through online social media, such as Twitter, citizens create Volunteered Geographic Information (VGI. To effectively use this information for disaster management, we developed a VGI framework for the discovery of VGI. This framework consists of four components: (i a VGI brokering module to provide a standard service interface to retrieve VGI from multiple resources based on spatial, temporal, and semantic parameters; (ii a VGI quality control component, which employs semantic filtering and cross-referencing techniques to evaluate VGI; (iii a VGI publisher module, which uses a service-based delivery mechanism to disseminate VGI, and (iv a VGI discovery component to locate, browse, and query metadata about available VGI datasets. In a case study we employed a FOSS (Free and Open Source Software strategy, open standards/specifications, and free/open data to show the utility of the framework. We demonstrate that the framework can facilitate data discovery for disaster management. The addition of quality metrics and a single aggregated source of relevant crisis VGI will allow users to make informed policy choices that could save lives, meet basic humanitarian needs earlier, and perhaps limit environmental and economic damage.

  17. Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

    Directory of Open Access Journals (Sweden)

    Y. Lei

    2012-01-01

    Full Text Available Using OMI (Ozone Monitoring Instrument tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem, we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82 with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite

  18. Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

    Directory of Open Access Journals (Sweden)

    Y. Lei

    2012-05-01

    Full Text Available Using OMI (Ozone Monitoring Instrument tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem, we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82 with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite

  19. Direct and indirect bottom-up and top-down forces shape the abundance of the orb-web spider Argiope bruennichi

    OpenAIRE

    Bruggisser, Odile T; Sandau, Nadine; Blandenier, Gilles; Fabian, Yvonne; Kehrli, Patrik; Aebi, Alex; Russell E Naisbit; Bersier, Louis-Félix

    2014-01-01

    Species abundance in local communities is determined by bottom-up and top-down processes, which can act directly and indirectly on the focal species. Studies examining these effects simultaneously are rare. Here we explore the direct top-down and direct and indirect bottom-up forces regulating the abundance and predation success of an intermediate predator, the web-building spider Argiope bruennichi (Araneae: Araneidae). We manipulated plant diversity (2, 6, 12 or 20 sown species) in 9 wildfl...

  20. Balancing Top-Down, Bottom-Up, and Peer-to-Peer Approaches to Sustaining Distance Training

    Directory of Open Access Journals (Sweden)

    Zane BERGE

    2006-07-01

    Full Text Available Many distance training case studies identify distance training leadership as bottom-up, whereas much of the literature suggests a need for strategic, top-down approaches. With change management as an overarching framework, approaches to sustaining distance training that originate at different levels of the organization are explored. Special attention is paid to the content of the change messages involved, guided by Rogers’ five attributes of innovations. Research of change management and distance training literature suggests a combination of approaches that should fit the organizational culture as well as correctly address genuine concerns at the various organizational levels. A properly balanced approach could lead to new levels of communication and understanding in a learning organization and to distance training being sustained as a business process

  1. Mass Spectrometry Applied to Bottom-Up Proteomics: Entering the High-Throughput Era for Hypothesis Testing

    Science.gov (United States)

    Gillet, Ludovic C.; Leitner, Alexander; Aebersold, Ruedi

    2016-06-01

    Proteins constitute a key class of molecular components that perform essential biochemical reactions in living cells. Whether the aim is to extensively characterize a given protein or to perform high-throughput qualitative and quantitative analysis of the proteome content of a sample, liquid chromatography coupled to tandem mass spectrometry has become the technology of choice. In this review, we summarize the current state of mass spectrometry applied to bottom-up proteomics, the approach that focuses on analyzing peptides obtained from proteolytic digestion of proteins. With the recent advances in instrumentation and methodology, we show that the field is moving away from providing qualitative identification of long lists of proteins to delivering highly consistent and accurate quantification values for large numbers of proteins across large numbers of samples. We believe that this shift will have a profound impact for the field of proteomics and life science research in general.

  2. The faith of a physicist reflections of a bottom-up thinker : the Gifford lectures for 1993-4

    CERN Document Server

    Polkinghorne, John C

    1994-01-01

    Is it possible to think like a scientist and yet have the faith of a Christian? Although many Westerners might say no, there are also many critically minded individuals who entertain what John Polkinghorne calls a "wistful wariness" toward religion--they feel unable to accept religion on rational grounds yet cannot dismiss it completely. Polkinghorne, both a particle physicist and Anglican priest, here explores just what rational grounds there could be for Christian beliefs, maintaining that the quest for motivated understanding is a concern shared by scientists and religious thinkers alike. Anyone who assumes that religion is based on unquestioning certainties, or that it need not take into account empirical knowledge, will be challenged by Polkinghorne's bottom-up examination of Christian beliefs about events ranging from creation to the resurrection. The author organizes his inquiry around the Nicene Creed, an early statement that continues to summarize Christian beliefs. He applies to each of its tenets ...

  3. Identifying robust clusters and multi-community nodes by combining top-down and bottom-up approaches to clustering

    CERN Document Server

    Gaiteri, Chris; Szymanski, Boleslaw; Kuzmin, Konstantin; Xie, Jierui; Lee, Changkyu; Blanche, Timothy; Neto, Elias Chaibub; Huang, Su-Chun; Grabowski, Thomas; Madhyastha, Tara; Komashko, Vitalina

    2015-01-01

    Biological functions are often realized by groups of interacting molecules or cells. Membership in these groups may overlap when molecules or cells are reused in multiple functions. Traditional clustering methods assign each component to one group. Noisy measurements are common in high-throughput biological datasets. These two limitations reduce our ability to accurately define clusters in biological datasets and to interpret their biological functions. To address these limitations, we designed an algorithm called SpeakEasy, which detects overlapping or non-overlapping communities in biological networks. Input to SpeakEasy can be physical networks, such as molecular interactions, or inferred networks, such as gene coexpression networks. The networks can be directed or undirected, and may contain negative links. SpeakEasy combines traditional bottom-up and top-down approaches to clustering, by creating competition between clusters. Nodes that oscillate between multiple clusters in this competition are classifi...

  4. Aid effectiveness from Rome to Busan: some progress but lacking bottom-up approaches or behaviour changes.

    Science.gov (United States)

    Martini, Jessica; Mongo, Roch; Kalambay, Hyppolite; Fromont, Anne; Ribesse, Nathalie; Dujardin, Bruno

    2012-07-01

    The Busan partnership adopted at the 4th High Level Forum on Aid Effectiveness at the end of last year is a significant step forward towards the improvement of aid quality and the promotion of development. In particular, the inclusiveness achieved in Busan and the shift in discourse from 'aid effectiveness' to 'development effectiveness' are emblematic. However, key challenges still remain. Firstly, decision-making should be more bottom-up, finding ways to take into account the populations' needs and experiences and to enhance self-learning dynamics during the policy process. Today, it is particularly necessary to define what 'development' means at country level, according to the aspirations of particular categories of people and meeting operational and local expectations. Secondly, changes in language should be followed by a real change in mindset. Development stakeholders should further adapt their procedures to the reality of complex systems in which development interventions are being dealt with. PMID:22583911

  5. Radiographic Evaluation of Children with Febrile Urinary Tract Infection: Bottom-Up, Top-Down, or None of the Above?

    Directory of Open Access Journals (Sweden)

    Michaella M. Prasad

    2012-01-01

    Full Text Available The proper algorithm for the radiographic evaluation of children with febrile urinary tract infection (FUTI is hotly debated. Three studies are commonly administered: renal-bladder ultrasound (RUS, voiding cystourethrogram (VCUG, and dimercapto-succinic acid (DMSA scan. However, the order in which these tests are obtained depends on the methodology followed: bottom-up or top-down. Each strategy carries advantages and disadvantages, and some groups now advocate even less of a workup (none of the above due to the current controversies about treatment when abnormalities are diagnosed. New technology is available and still under investigation, but it may help to clarify the interplay between vesicoureteral reflux, renal scarring, and dysfunctional elimination in the future.

  6. Bottom-Up Fabrication of Nanopatterned Polymers on DNA Origami by In Situ Atom-Transfer Radical Polymerization.

    Science.gov (United States)

    Tokura, Yu; Jiang, Yanyan; Welle, Alexander; Stenzel, Martina H; Krzemien, Katarzyna M; Michaelis, Jens; Berger, Rüdiger; Barner-Kowollik, Christopher; Wu, Yuzhou; Weil, Tanja

    2016-05-01

    Bottom-up strategies to fabricate patterned polymers at the nanoscale represent an emerging field in the development of advanced nanodevices, such as biosensors, nanofluidics, and nanophotonics. DNA origami techniques provide access to distinct architectures of various sizes and shapes and present manifold opportunities for functionalization at the nanoscale with the highest precision. Herein, we conduct in situ atom-transfer radical polymerization (ATRP) on DNA origami, yielding differently nanopatterned polymers of various heights. After cross-linking, the grafted polymeric nanostructures can even stably exist in solution without the DNA origami template. This straightforward approach allows for the fabrication of patterned polymers with low nanometer resolution, which provides access to unique DNA-based functional hybrid materials. PMID:27058968

  7. A two-step combination of top-down and bottom-up fire emission estimates at regional and global scales: strengths and main uncertainties

    Science.gov (United States)

    Sofiev, Mikhail; Soares, Joana; Kouznetsov, Rostislav; Vira, Julius; Prank, Marje

    2016-04-01

    Top-down emission estimation via inverse dispersion modelling is used for various problems, where bottom-up approaches are difficult or highly uncertain. One of such areas is the estimation of emission from wild-land fires. In combination with dispersion modelling, satellite and/or in-situ observations can, in principle, be used to efficiently constrain the emission values. This is the main strength of the approach: the a-priori values of the emission factors (based on laboratory studies) are refined for real-life situations using the inverse-modelling technique. However, the approach also has major uncertainties, which are illustrated here with a few examples of the Integrated System for wild-land Fires (IS4FIRES). IS4FIRES generates the smoke emission and injection profile from MODIS and SEVIRI active-fire radiative energy observations. The emission calculation includes two steps: (i) initial top-down calibration of emission factors via inverse dispersion problem solution that is made once using training dataset from the past, (ii) application of the obtained emission coefficients to individual-fire radiative energy observations, thus leading to bottom-up emission compilation. For such a procedure, the major classes of uncertainties include: (i) imperfect information on fires, (ii) simplifications in the fire description, (iii) inaccuracies in the smoke observations and modelling, (iv) inaccuracies of the inverse problem solution. Using examples of the fire seasons 2010 in Russia, 2012 in Eurasia, 2007 in Australia, etc, it is pointed out that the top-down system calibration performed for a limited number of comparatively moderate cases (often the best-observed ones) may lead to errors in application to extreme events. For instance, the total emission of 2010 Russian fires is likely to be over-estimated by up to 50% if the calibration is based on the season 2006 and fire description is simplified. Longer calibration period and more sophisticated parameterization

  8. China's energy and emissions outlook to 2050: Perspectives from bottom-up energy end-use model

    International Nuclear Information System (INIS)

    Although China became the world's largest CO2 emitter in 2007, the country has also taken serious actions to reduce its energy and carbon intensity. This study uses the bottom-up LBNL China End-Use Energy Model to assess the role of energy efficiency policies in transitioning China to a lower emission trajectory and meeting its 2020 intensity reduction goals. Two scenarios – Continued Improvement and Accelerated Improvement – were developed to assess the impact of actions already taken by the Chinese government as well as planned and potential actions, and to evaluate the potential for China to reduce energy demand and emissions. This scenario analysis presents an important modeling approach based in the diffusion of end-use technologies and physical drivers of energy demand and thereby help illuminate China's complex and dynamic drivers of energy consumption and implications of energy efficiency policies. The findings suggest that China's CO2 emissions will not likely continue growing throughout this century because of saturation effects in appliances, residential and commercial floor area, roadways, fertilizer use; and population peak around 2030 with slowing urban population growth. The scenarios also underscore the significant role that policy-driven efficiency improvements will play in meeting 2020 carbon mitigation goals along with a decarbonized power supply. - Highlights: ► Bottom-up model of China's energy and CO2 reductions through sectoral policies. ► 2 scenarios evaluate impact of actions already taken/planned and future potential. ► China's CO2 will not likely continue growing through 2050 due to saturation effects. ► Results emphasize both policy-driven efficiency and decarbonized power supply.

  9. A bottom-up analysis of China’s iron and steel industrial energy consumption and CO2 emissions

    International Nuclear Information System (INIS)

    Highlights: • This paper analyses future steel demand and steel scrap consumption through bottom-up analysis. • Steel scrap consumption is analyzed individually by different sources. • Steel consumption and energy consumption will peak at around 2020 and 2015 respectively. • Energy intensity and CO2 intensity of steel production will decrease obviously in the future. • Energy efficiency improvement and structural change will play different roles in near- and long-term CO2 mitigations. - Abstract: China’s steel industry has grown significantly since the mid-1990s, and has been the backbone of Chinese heavy industry. It is also the most energy intensive industrial sector in China, accounting for 16.1% of total energy consumption in 2010. To assess energy consumption and CO2 emissions from China’s steel industry, a system dynamics model and a bottom-up energy system model-TIMES (The Integrated MARKAL-EFOM System) were used to analyze steel demand, energy consumption and CO2 emissions from China’s iron and steel industry from 2010 to 2050. The model results suggest that steel production in China will rise from 627 Mt in 2010, to a peak of 772 Mt in 2020, and then gradually decrease to 527 Mt in 2050. The share of Electric Arc Furnace (EAF) steel production will also increase significantly from 9.8% in 2010, to 45.6% in 2050. With the deployment of energy conservation technologies, such as Coke Dry Quenching, exhaust gas and heat recovery equipment, energy intensity and CO2 intensity of steel production will keep decreasing during the modeling period. In the near future, reductions in energy intensity and CO2 intensity will rely more on energy efficiency improvements; however, from a long-term perspective, structural change-the increasing share of EAF steel production, will be of great significance

  10. A comparison of top-down and bottom-up approaches to benthic habitat mapping to inform offshore wind energy development

    Science.gov (United States)

    LaFrance, Monique; King, John W.; Oakley, Bryan A.; Pratt, Sheldon

    2014-07-01

    heterogeneity over various spatial scales. The approaches were also able to integrate various data at differing spatial resolutions. The classification outputs exhibited similar results, including the number of habitat classes generated, the number of species defining the classes, the level of distinction of the biological communities, and dominance by tube-building amphipods. These results indicate that both approaches are able to discern a comparable degree of habitat variability and produce cohesive macrofaunal assemblages. The mapping approaches identify broadly similar benthic habitats at the two study sites and methods were able to distinguish the differing levels of heterogeneity between them. The top-down approach to habitat classification was faster and simpler to accomplish with the data available in this study when compared to the bottom-up approach. Additionally, the top-down approach generated full-coverage habitat classes that are clearly delineated and can easily be interpreted by the map user, which is desirable from a management perspective for providing a more complete assessment of the areas of interest. However, a higher level of biological variability was noted in some of the habitat classes created, indicating that the biological communities present in this area are influenced by factors not captured in the broad-scale geological habitat units used in this approach. The bottom-up approach was valuable in its ability to more clearly define macrofaunal assemblages among habitats, discern finer-scale habitat characteristics, and directly assess the degree of macrofaunal assemblage variability captured by the environmental parameters. From a user perspective, the map is more complex, which may be perceived as a limitation, though likely reflects natural gradations in habitat structure and likely presents a more ecologically realistic portrayal of the study areas. Though more comprehensive, the bottom-up approach in this study was limited by the reliance on

  11. Comparing bottom-up and top-down approaches at the landscape scale, including agricultural activities and water systems, at the Roskilde Fjord, Denmark

    Science.gov (United States)

    Lequy, Emeline; Ibrom, Andreas; Ambus, Per; Massad, Raia-Silvia; Markager, Stiig; Asmala, Eero; Garnier, Josette; Gabrielle, Benoit; Loubet, Benjamin

    2015-04-01

    The greenhouse gas nitrous oxide (N2O) mainly originates in direct emissions from agricultural soils due to microbial reactions stimulated by the use of nitrogen fertilisers. Indirect N2O emissions from water systems due to nitrogen leaching and deposition from crop fields range between 26 and 37% of direct agricultural emissions, indicating their potential importance and uncertainty (Reay et al. 2012). The study presented here couples a top-down approach with eddy covariance (EC) and a bottom-up approach using different models and measurements. A QCL sensor at 96-m height on a tall tower measures the emissions of N2O from 1100 ha of crop fields and from the south part of the Roskilde fjord, in a 5-km radius area around the tall tower at Roskilde, Denmark. The bottom-up approach includes ecosystem modelling with CERES-EGC for the crops and PaSIM for the grasslands, and the N2O fluxes from the Roskilde fjord are derived from N2O sea water concentration measurements. EC measurements are now available from July to December 2014, and indicate a magnitude of the emissions from the crop fields around 0.2 mg N2O-N m-2 day-1 (range -9 to 5) which is consistent with the CERES-EGC simulations and calculations using IPCC emission factors. N2O fluxes from the Roskilde fjord in May and July indicated quite constant N2O concentrations around 0.1 µg N L-1 despite variations of nitrate and ammonium in the fjord. The calculated fluxes from these concentrations and the tall tower measurements consistently ranged between -7 and 6 mg N2O-N m-2 day-1. The study site also contains a waste water treatment plant, whose direct emissions will be measured in early 2015 using a dynamic plume tracer dispersion method (Mønster et al. 2014). A refined source attribution methodology together with more measurements and simulations of the N2O fluxes from the different land uses in this study site will provide a clearer view of the dynamics and budgets of N2O at the regional scale. The

  12. Hybrid bottom-up/top-down energy and economy outlooks: a survey of the IMACLIM-S experiments

    Directory of Open Access Journals (Sweden)

    Frédéric eGhersi

    2015-11-01

    Full Text Available In this paper we survey the research undertaken at the Centre International de Recherche sur l’Environnement et le Développement (CIRED on the combination of the IMACLIM-S macroeconomic model with ‘bottom-up’ energy modeling, with a view to associate the strengths and circumvent the limitations of both approaches to energy-economy-environment (E3 prospective modeling. We start by presenting the two methodological avenues of coupling IMACLIM-S with detailed energy systems models pursued at CIRED since the late 1990s’: (1 the calibration of the behavioral functions of IMACLIM-S that represent the producers’ and consumers’ trade-offs between inputs or consumptions, on a large set of bottom-up modeling results; (2 the coupling of IMACLIM-S to some bottom-up model through the iterative exchange of some of each model’s outputs as the other model’s inputs until convergence of the exchanged data, comprising the main macroeconomic drivers and energy systems variables. In the following section, we turn to numerical application and address the prerequisite of harmonizing national accounts, energy balance and energy price data to produce consistent hybrid input-output matrices as a basis of scenario exploration. We highlight how this data treatment step reveals the discrepancies and biases induced by sticking to the conventional modeling usage of uniform pricing of homogeneous goods. IMACLIM-S rather calibrates agent-specific margins, which we introduce and comment upon. In a further section we sum up the results of 4 IMACLIM-S experiments, insisting upon the value-added of hybrid modeling. These varied experiments regard international climate policy burden sharing; the more general numerical consequences of shifting from a biased standard CGE model perspective to the hybrid IMACLIM approach; the macroeconomic consequences of a strong development of electric mobility in the European Union; and the resilience of public debts to energy shocks

  13. Intentional action processing results from automatic bottom-up attention: An EEG-investigation into the Social Relevance Hypothesis using hypnosis.

    Science.gov (United States)

    Neufeld, Eleonore; Brown, Elliot C; Lee-Grimm, Sie-In; Newen, Albert; Brüne, Martin

    2016-05-01

    Social stimuli grab our attention. However, it has rarely been investigated how variations in attention affect the processing of social stimuli, although the answer could help us uncover details of social cognition processes such as action understanding. In the present study, we examined how changes to bottom-up attention affects neural EEG-responses associated with intentional action processing. We induced an increase in bottom-up attention by using hypnosis. We recorded the electroencephalographic μ-wave suppression of hypnotized participants when presented with intentional actions in first and third person perspective in a video-clip paradigm. Previous studies have shown that the μ-rhythm is selectively suppressed both when executing and observing goal-directed motor actions; hence it can be used as a neural signal for intentional action processing. Our results show that neutral hypnotic trance increases μ-suppression in highly suggestible participants when they observe intentional actions. This suggests that social action processing is enhanced when bottom-up attentional processes are predominant. Our findings support the Social Relevance Hypothesis, according to which social action processing is a bottom-up driven attentional process, and can thus be altered as a function of bottom-up processing devoted to a social stimulus. PMID:26998562

  14. Analysis of the Economic Impact of Large-Scale Deployment of Biomass Resources for Energy and Materials in the Netherlands. Appendix 1. Bottom-up Scenarios

    International Nuclear Information System (INIS)

    The Bio-based Raw Materials Platform (PGG), part of the Energy Transition in The Netherlands, commissioned the Agricultural Economics Research Institute (LEI) and the Copernicus Institute of Utrecht University to conduct research on the macro-economic impact of large scale deployment of biomass for energy and materials in the Netherlands. Two model approaches were applied based on a consistent set of scenario assumptions: a bottom-up study including technoeconomic projections of fossil and bio-based conversion technologies and a topdown study including macro-economic modelling of (global) trade of biomass and fossil resources. The results of the top-down and bottom-up modelling work are reported separately. The results of the synthesis of the modelling work are presented in the main report. This report (part 1) presents scenarios for future biomass use for energy and materials, and analyses the consequences on energy supply, chemical productions, costs and greenhouse gas (GHG) emissions with a bottom-up approach. The bottom-up projections, as presented in this report, form the basis for modelling work using the top-down macro-economic model (LEITAP) to assess the economic impact of substituting fossil-based energy carriers with biomass in the Netherlands. The results of the macro-economic modelling work, and the linkage between the results of the bottom-up and top-down work, will be presented in the top-down economic part and synthesis report of this study

  15. When top-down becomes bottom up: behaviour of hyperdense howler monkeys (Alouatta seniculus trapped on a 0.6 ha island.

    Directory of Open Access Journals (Sweden)

    Gabriela Orihuela

    Full Text Available Predators are a ubiquitous presence in most natural environments. Opportunities to contrast the behaviour of a species in the presence and absence of predators are thus rare. Here we report on the behaviour of howler monkey groups living under radically different conditions on two land-bridge islands in Lago Guri, Venezuela. One group of 6 adults inhabited a 190-ha island (Danto where they were exposed to multiple potential predators. This group, the control, occupied a home range of 23 ha and contested access to food resources with neighbouring groups in typical fashion. The second group, containing 6 adults, was isolated on a remote, predator-free 0.6 ha islet (Iguana offering limited food resources. Howlers living on the large island moved, fed and rested in a coherent group, frequently engaged in affiliative activities, rarely displayed agonistic behaviour and maintained intergroup spacing through howling. In contrast, the howlers on Iguana showed repulsion, as individuals spent most of their time spaced widely around the perimeter of the island. Iguana howlers rarely engaged in affiliative behaviour, often chased or fought with one another and were not observed to howl. These behaviors are interpreted as adjustments to the unrelenting deprivation associated with bottom-up limitation in a predator-free environment.

  16. When top-down becomes bottom up: behaviour of hyperdense howler monkeys (Alouatta seniculus) trapped on a 0.6 ha island.

    Science.gov (United States)

    Orihuela, Gabriela; Terborgh, John; Ceballos, Natalia; Glander, Kenneth

    2014-01-01

    Predators are a ubiquitous presence in most natural environments. Opportunities to contrast the behaviour of a species in the presence and absence of predators are thus rare. Here we report on the behaviour of howler monkey groups living under radically different conditions on two land-bridge islands in Lago Guri, Venezuela. One group of 6 adults inhabited a 190-ha island (Danto) where they were exposed to multiple potential predators. This group, the control, occupied a home range of 23 ha and contested access to food resources with neighbouring groups in typical fashion. The second group, containing 6 adults, was isolated on a remote, predator-free 0.6 ha islet (Iguana) offering limited food resources. Howlers living on the large island moved, fed and rested in a coherent group, frequently engaged in affiliative activities, rarely displayed agonistic behaviour and maintained intergroup spacing through howling. In contrast, the howlers on Iguana showed repulsion, as individuals spent most of their time spaced widely around the perimeter of the island. Iguana howlers rarely engaged in affiliative behaviour, often chased or fought with one another and were not observed to howl. These behaviors are interpreted as adjustments to the unrelenting deprivation associated with bottom-up limitation in a predator-free environment. PMID:24743575

  17. Integrating Source Apportionment Tracers into a Bottom-up Inventory of Methane Emissions in the Barnett Shale Hydraulic Fracturing Region.

    Science.gov (United States)

    Townsend-Small, Amy; Marrero, Josette E; Lyon, David R; Simpson, Isobel J; Meinardi, Simone; Blake, Donald R

    2015-07-01

    A growing dependence on natural gas for energy may exacerbate emissions of the greenhouse gas methane (CH4). Identifying fingerprints of these emissions is critical to our understanding of potential impacts. Here, we compare stable isotopic and alkane ratio tracers of natural gas, agricultural, and urban CH4 sources in the Barnett Shale hydraulic fracturing region near Fort Worth, Texas. Thermogenic and biogenic sources were compositionally distinct, and emissions from oil wells were enriched in alkanes and isotopically depleted relative to natural gas wells. Emissions from natural gas production varied in δ(13)C and alkane ratio composition, with δD-CH4 representing the most consistent tracer of natural gas sources. We integrated our data into a bottom-up inventory of CH4 for the region, resulting in an inventory of ethane (C2H6) sources for comparison to top-down estimates of CH4 and C2H6 emissions. Methane emissions in the Barnett are a complex mixture of urban, agricultural, and fossil fuel sources, which makes source apportionment challenging. For example, spatial heterogeneity in gas composition and high C2H6/CH4 ratios in emissions from conventional oil production add uncertainty to top-down models of source apportionment. Future top-down studies may benefit from the addition of δD-CH4 to distinguish thermogenic and biogenic sources. PMID:26148556

  18. Bottom-Up Fabrication of Activated Carbon Fiber for All-Solid-State Supercapacitor with Excellent Electrochemical Performance.

    Science.gov (United States)

    Ma, Wujun; Chen, Shaohua; Yang, Shengyuan; Chen, Wenping; Weng, Wei; Zhu, Meifang

    2016-06-15

    Activated carbon (AC) is the most extensively used electrode material for commercial electric double layer capacitors (EDLC) given its high specific surface area (SSA) and moderate cost. However, AC is primarily used in the forms of powders, which remains a big challenge in developing AC powders into continuous fibers. If AC powders can be processed into fiber, then they may be scaled up for practical applications to supercapacitors (SCs) and satisfy the rapid development of flexible electronics. Herein, we report a bottom-up method to fabricate AC fiber employing graphene oxide (GO) as both dispersant and binder. After chemical reduction, the fiber has high electrical conductivity (185 S m(-1)), high specific surface area (1476.5 m(2) g(-1)), and good mechanical flexibility. An all solid-state flexible SC was constructed using the prepared fiber as electrode, which is free of binder, conducting additive, and additional current collector. The fiber-shaped SC shows high capacitance (27.6 F cm(-3) or 43.8 F g(-1), normalized to the two-electrode volume), superior cyclability (90.4% retention after 10 000 cycles), and good bendability (96.8% retention after bending 1000 times). PMID:27239680

  19. Evaluating the impact of odors from the 1955 landfills in China using a bottom-up approach.

    Science.gov (United States)

    Cai, Bofeng; Wang, Jinnan; Long, Ying; Li, Wanxin; Liu, Jianguo; Ni, Zhe; Bo, Xin; Li, Dong; Wang, Jianghao; Chen, Xuejing; Gao, Qingxian; Zhang, Lixiao

    2015-12-01

    Landfill odors have created a major concern for the Chinese public. Based on the combination of a first order decay (FOD) model and a ground-level point source Gaussian dispersion model, the impacts from odors emitted from the 1955 landfills in China are evaluated in this paper. Our bottom-up approach uses basic data related to each landfill to achieve a more accurate and comprehensive understanding of impact of landfill odors. Results reveal that the average radius of impact of landfill odors in China is 796 m, while most landfills (46.85%) are within the range of 400-1000 m, in line with the results from previous studies. The total land area impacted by odors has reached 837,476 ha, accounting for 0.09% of China's land territory. Guangdong and Sichuan provinces have the largest land areas impacted by odors, while Tibet Autonomous Region and Tianjin Municipality have the smallest. According to the CALPUFF (California Puff) model and an analysis of social big data, the overall uncertainty of our calculation of the range of odor impacts is roughly -32.88% to 32.67%. This type of study is essential for gaining an accurate and detailed estimation of the affected human population and will prove valuable for addressing the current Not In My Back Yard (NIMBY) challenge in China. PMID:26398549

  20. Beyond Defining the Smart City. Meeting Top-Down and Bottom-Up Approaches in the Middle

    Directory of Open Access Journals (Sweden)

    Jonas Breuer

    2014-05-01

    Full Text Available This paper aims to better frame the discussion and the various, divergent operationalisations and interpretations of the Smart City concept. We start by explicating top-down approaches to the Smart City, followed by what purely bottom-up initiatives can look like. We provide a clear overview of stakeholders’ different viewpoints on the city of tomorrow. Particularly the consequences and potential impacts of these differing interpretations and approaches should be of specific interest to researchers, policy makers, city administrations, private actors and anyone involved and concerned with life in cities. Therefore the goal of this article is not so much answering the question of what the Smart City is, but rather what the concept can mean for different stakeholders as well as the consequences of their interpretation. We do this by assembling an eclectic overview, bringing together definitions, examples and operationalisations from academia, policy and industry as well as identifying major trends and approaches to realizing the Smart City. We add to the debate by proposing a different approach that starts from the collective, collaboration and context when researching Smart City initiatives.

  1. Biochemistry-directed hollow porous microspheres: bottom-up self-assembled polyanion-based cathodes for sodium ion batteries

    Science.gov (United States)

    Lin, Bo; Li, Qiufeng; Liu, Baodong; Zhang, Sen; Deng, Chao

    2016-04-01

    Biochemistry-directed synthesis of functional nanomaterials has attracted great interest in energy storage, catalysis and other applications. The unique ability of biological systems to guide molecule self-assembling facilitates the construction of distinctive architectures with desirable physicochemical characteristics. Herein, we report a biochemistry-directed ``bottom-up'' approach to construct hollow porous microspheres of polyanion materials for sodium ion batteries. Two kinds of polyanions, i.e. Na3V2(PO4)3 and Na3.12Fe2.44(P2O7)2, are employed as cases in this study. The microalgae cell realizes the formation of a spherical ``bottom'' bio-precursor. Its tiny core is subjected to destruction and its tough shell tends to carbonize upon calcination, resulting in the hollow porous microspheres for the ``top'' product. The nanoscale crystals of the polyanion materials are tightly enwrapped by the highly-conductive framework in the hollow microsphere, resulting in the hierarchical nano-microstructure. The whole formation process is disclosed as a ``bottom-up'' mechanism. Moreover, the biochemistry-directed self-assembly process is confirmed to play a crucial role in the construction of the final architecture. Taking advantage of the well-defined hollow-microsphere architecture, the abundant interior voids and the highly-conductive framework, polyanion materials show favourable sodium-intercalation kinetics. Both materials are capable of high-rate long-term cycling. After five hundred cycles at 20 C and 10 C, Na3V2(PO4)3 and Na3.12Fe2.44(P2O7)2 retain 96.2% and 93.1% of the initial capacity, respectively. Therefore, the biochemistry-directed technique provides a low-cost, highly-efficient and widely applicable strategy to produce high-performance polyanion-based cathodes for sodium ion batteries.Biochemistry-directed synthesis of functional nanomaterials has attracted great interest in energy storage, catalysis and other applications. The unique ability of

  2. Top-down versus bottom-up estimates of methane fluxes over the East Siberian Arctic Shelf

    Science.gov (United States)

    Shakhova, N. E.; Semiletov, I. P.; Repina, I.; Salyuk, A.; Kosmach, D.; Chernykh, D.; Aniferov, A.

    2014-12-01

    Global methane (CH4) emissions are currently quantified from statistical data without testing the results against either distribution of the actual atmospheric CH4 concentrations observed in different part of the globe or the regional dynamics of these concentrations. Measurement methods despite been improved remarkably in the past few years, especially with the advent of new optical and satellite-derived methods, are limited in their applicability in the Arctic. Modeling methodologies are still under development and cannot help to evolve very coarse global-scale understanding of CH4 sources to resolution of regional-scale emissions. As a result, contribution of the Arctic sources in the global CH4 budget are yet to be quantified adequately. We used a decadal observational data set collected from the water column and from the atmospheric boundary layer (ABL) over the East Siberian Arctic Shelf (ESAS), which is the largest continental shelf, to determine the minimum source strength required to explain observed seasonally increased concentration of CH4 in the ABL. The results of top-down modeling performed by implementing a simple box model show a good agreement with results of bottom-up estimates made using interpretation of in-situ calibrated sonar data.

  3. Encouraging the pursuit of advanced degrees in science and engineering: Top-down and bottom-up methodologies

    Science.gov (United States)

    Maddox, Anthony B.; Smith-Maddox, Renee P.; Penick, Benson E.

    1989-01-01

    The MassPEP/NASA Graduate Research Development Program (GRDP) whose objective is to encourage Black Americans, Mexican Americans, American Indians, Puerto Ricans, and Pacific Islanders to pursue graduate degrees in science and engineering is described. The GRDP employs a top-down or goal driven methodology through five modules which focus on research, graduate school climate, technical writing, standardized examinations, and electronic networking. These modules are designed to develop and reinforce some of the skills necessary to seriously consider the goal of completing a graduate education. The GRDP is a community-based program which seeks to recruit twenty participants from a pool of Boston-area undergraduates enrolled in engineering and science curriculums and recent graduates with engineering and science degrees. The program emphasizes that with sufficient information, its participants can overcome most of the barriers perceived as preventing them from obtaining graduate science and engineering degrees. Experience has shown that the top-down modules may be complemented by a more bottom-up or event-driven methodology. This approach considers events in the academic and professional experiences of participants in order to develop the personal and leadership skills necessary for graduate school and similar endeavors.

  4. Pitch and spectral resolution: A systematic comparison of bottom-up cues for top-down repair of degraded speech.

    Science.gov (United States)

    Clarke, Jeanne; Başkent, Deniz; Gaudrain, Etienne

    2016-01-01

    The brain is capable of restoring missing parts of speech, a top-down repair mechanism that enhances speech understanding in noisy environments. This enhancement can be quantified using the phonemic restoration paradigm, i.e., the improvement in intelligibility when silent interruptions of interrupted speech are filled with noise. Benefit from top-down repair of speech differs between cochlear implant (CI) users and normal-hearing (NH) listeners. This difference could be due to poorer spectral resolution and/or weaker pitch cues inherent to CI transmitted speech. In CIs, those two degradations cannot be teased apart because spectral degradation leads to weaker pitch representation. A vocoding method was developed to evaluate independently the roles of pitch and spectral resolution for restoration in NH individuals. Sentences were resynthesized with different spectral resolutions and with either retaining the original pitch cues or discarding them all. The addition of pitch significantly improved restoration only at six-bands spectral resolution. However, overall intelligibility of interrupted speech was improved both with the addition of pitch and with the increase in spectral resolution. This improvement may be due to better discrimination of speech segments from the filler noise, better grouping of speech segments together, and/or better bottom-up cues available in the speech segments. PMID:26827034

  5. Bioenergy decision-making of farms in Northern Finland: Combining the bottom-up and top-down perspectives

    International Nuclear Information System (INIS)

    Finnish farmers' role as energy producers is small compared to their role as energy resource owners. Since climate and energy policy in Finland continues favoring large-scale energy visions, additional investment support for agriculture will stay modest. To utilize fully the energy potential in farms, we analyze the farmers' decision-making environment. First, we present an overview of the Finnish energy policy and economy and their effect on farms (the top-down perspective). Then we analyze the drivers behind the bioenergy decisions of farms in general and in the Oulu region, located in Northern Finland (the bottom-up perspective). There is weak policy coherence between national and regional energy efforts. Strong pressure is placed on farmers to improve their business and marketing knowledge, innovation and financial abilities, education level, and networking skills. In the Oulu region, bioenergy forerunners can be divided in three different groups - investors, entrepreneurs and hobbyists - that have different levels of commitment to their energy businesses. This further stresses the importance of getting quality business services from numerous service providers.

  6. Bioenergy decision-making of farms in Northern Finland: Combining the bottom-up and top-down perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Snaekin, Juha-Pekka, E-mail: juhapekkasnakin@luukku.co [University of Oulu, Department of Geography, P.O. Box 3000, FIN-90014 Oulu (Finland); Muilu, Toivo; Pesola, Tuomo [University of Oulu, Department of Geography, P.O. Box 3000, FIN-90014 Oulu (Finland)

    2010-10-15

    Finnish farmers' role as energy producers is small compared to their role as energy resource owners. Since climate and energy policy in Finland continues favoring large-scale energy visions, additional investment support for agriculture will stay modest. To utilize fully the energy potential in farms, we analyze the farmers' decision-making environment. First, we present an overview of the Finnish energy policy and economy and their effect on farms (the top-down perspective). Then we analyze the drivers behind the bioenergy decisions of farms in general and in the Oulu region, located in Northern Finland (the bottom-up perspective). There is weak policy coherence between national and regional energy efforts. Strong pressure is placed on farmers to improve their business and marketing knowledge, innovation and financial abilities, education level, and networking skills. In the Oulu region, bioenergy forerunners can be divided in three different groups - investors, entrepreneurs and hobbyists - that have different levels of commitment to their energy businesses. This further stresses the importance of getting quality business services from numerous service providers.

  7. Bioenergy decision-making of farms in Northern Finland. Combining the bottom-up and top-down perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Snaekin, Juha-Pekka; Muilu, Toivo; Pesola, Tuomo [University of Oulu, Department of Geography, P.O. Box 3000, FIN-90014 Oulu (Finland)

    2010-10-15

    Finnish farmers' role as energy producers is small compared to their role as energy resource owners. Since climate and energy policy in Finland continues favoring large-scale energy visions, additional investment support for agriculture will stay modest. To utilize fully the energy potential in farms, we analyze the farmers' decision-making environment. First, we present an overview of the Finnish energy policy and economy and their effect on farms (the top-down perspective). Then we analyze the drivers behind the bioenergy decisions of farms in general and in the Oulu region, located in Northern Finland (the bottom-up perspective). There is weak policy coherence between national and regional energy efforts. Strong pressure is placed on farmers to improve their business and marketing knowledge, innovation and financial abilities, education level, and networking skills. In the Oulu region, bioenergy forerunners can be divided in three different groups - investors, entrepreneurs and hobbyists - that have different levels of commitment to their energy businesses. This further stresses the importance of getting quality business services from numerous service providers. (author)

  8. Calculating systems-scale energy efficiency and net energy returns: A bottom-up matrix-based approach

    International Nuclear Information System (INIS)

    In this paper we expand the work of Brandt and Dale (2011) on ERRs (energy return ratios) such as EROI (energy return on investment). This paper describes a “bottom-up” mathematical formulation which uses matrix-based computations adapted from the LCA (life cycle assessment) literature. The framework allows multiple energy pathways and flexible inclusion of non-energy sectors. This framework is then used to define a variety of ERRs that measure the amount of energy supplied by an energy extraction and processing pathway compared to the amount of energy consumed in producing the energy. ERRs that were previously defined in the literature are cast in our framework for calculation and comparison. For illustration, our framework is applied to include oil production and processing and generation of electricity from PV (photovoltaic) systems. Results show that ERR values will decline as system boundaries expand to include more processes. NERs (net energy return ratios) tend to be lower than GERs (gross energy return ratios). External energy return ratios (such as net external energy return, or NEER (net external energy ratio)) tend to be higher than their equivalent total energy return ratios. - Highlights: • An improved bottom-up mathematical method for computing net energy return metrics is developed. • Our methodology allows arbitrary numbers of interacting processes acting as an energy system. • Our methodology allows much more specific and rigorous definition of energy return ratios such as EROI or NER

  9. Integration of bottom-up and top-down models for the energy system. A practical case for Denmark

    International Nuclear Information System (INIS)

    The main objective of the project was to integrate the Danish macro economic model ADAM with elements from the energy simulation model BRUS, developed at Risoe. The project has been carried out by Risoe National Laboratory with assistance from the Ministry of Finance. A theoretical part focuses on the differences between top-down and bottom-up modelling of the energy-economy interaction. A combined hybrid model seems a relevant alternative to the two traditional approaches. The hybrid model developed is called Hybris and includes models for: supply of electricity and heat, household demand for electricity, and household demand for heat. These three models interact in a iterative procedure with the macro economic model ADAM through a number of links. A reference case as well as a number of scenarios illustrating the capabilities of the model has been set up.Hybris is a simulation model which is capable of analyzing combined CO2 reduction initiatives as regulation of the energy supply system and a CO2 tax in an integrated and consistent way. (au) 32 tabs., 98 ills., 55 refs

  10. Metatranscriptomic Evidence for Co-Occurring Top-Down and Bottom-Up Controls on Toxic Cyanobacterial Communities

    OpenAIRE

    Steffen, Morgan M; Belisle, B. Shafer; Watson, Sue B.; Boyer, Gregory L.; Bourbonniere, Richard A.; Wilhelm, Steven W.

    2015-01-01

    Little is known about the molecular and physiological function of co-occurring microbes within freshwater cyanobacterial harmful algal blooms (cHABs). To address this, community metatranscriptomes collected from the western basin of Lake Erie during August 2012 were examined. Using sequence data, we tested the hypothesis that the activity of the microbial community members is independent of community structure. Predicted metabolic and physiological functional profiles from spatially distinct ...

  11. Assessment of Historic Trend in Mobility and Energy Use in India Transportation Sector Using Bottom-up Approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nan; McNeil, Michael A.

    2009-05-01

    Transportation mobility in India has increased significantly in the past decades. From 1970 to 2000, motorized mobility (passenger-km) has risen by 888%, compared with an 88% population growth (Singh,2006). This contributed to many energy and environmental issues, and an energy strategy incorporates efficiency improvement and other measures needs to be designed. Unfortunately, existing energy data do not provide information on driving forces behind energy use and sometime show large inconsistencies. Many previous studies address only a single transportation mode such as passenger road travel; did not include comprehensive data collection or analysis has yet been done, or lack detail on energy demand by each mode and fuel mix. The current study will fill a considerable gap in current efforts, develop a data base on all transport modes including passenger air and water, and freight in order to facilitate the development of energy scenarios and assess significance of technology potential in a global climate change model. An extensive literature review and data collection has been done to establish the database with breakdown of mobility, intensity, distance, and fuel mix of all transportation modes. Energy consumption was estimated and compared with aggregated transport consumption reported in IEA India transportation energy data. Different scenarios were estimated based on different assumptions on freight road mobility. Based on the bottom-up analysis, we estimated that the energy consumption from 1990 to 2000 increased at an annual growth rate of 7% for the mid-range road freight growth case and 12% for the high road freight growth case corresponding to the scenarios in mobility, while the IEA data only shows a 1.7% growth rate in those years.

  12. Bottom-up engineering of biological systems through standard bricks: a modularity study on basic parts and devices.

    Directory of Open Access Journals (Sweden)

    Lorenzo Pasotti

    Full Text Available BACKGROUND: Modularity is a crucial issue in the engineering world, as it enables engineers to achieve predictable outcomes when different components are interconnected. Synthetic Biology aims to apply key concepts of engineering to design and construct new biological systems that exhibit a predictable behaviour. Even if physical and measurement standards have been recently proposed to facilitate the assembly and characterization of biological components, real modularity is still a major research issue. The success of the bottom-up approach strictly depends on the clear definition of the limits in which biological functions can be predictable. RESULTS: The modularity of transcription-based biological components has been investigated in several conditions. First, the activity of a set of promoters was quantified in Escherichia coli via different measurement systems (i.e., different plasmids, reporter genes, ribosome binding sites relative to an in vivo reference promoter. Second, promoter activity variation was measured when two independent gene expression cassettes were assembled in the same system. Third, the interchangeability of input modules (a set of constitutive promoters and two regulated promoters connected to a fixed output device (a logic inverter expressing GFP was evaluated. The three input modules provide tunable transcriptional signals that drive the output device. If modularity persists, identical transcriptional signals trigger identical GFP outputs. To verify this, all the input devices were individually characterized and then the input-output characteristic of the logic inverter was derived in the different configurations. CONCLUSIONS: Promoters activities (referred to a standard promoter can vary when they are measured via different reporter devices (up to 22%, when they are used within a two-expression-cassette system (up to 35% and when they drive another device in a functionally interconnected circuit (up to 44%. This paper

  13. Regime shift from phytoplankton to macrophyte dominance in a large river: Top-down versus bottom-up effects

    Energy Technology Data Exchange (ETDEWEB)

    Ibanez, Carles, E-mail: carles.ibanez@irta.cat [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alcaraz, Carles; Caiola, Nuno; Rovira, Albert; Trobajo, Rosa [IRTA Aquatic Ecosystems, Carretera Poble Nou, Km 5.5, 43540 St. Carles de la Rapita, Catalonia (Spain); Alonso, Miguel [United Research Services S.L., Urgell 143, 08036 Barcelona, Catalonia (Spain); Duran, Concha [Confederacion Hidrografica del Ebro, Sagasta 24-26, 50071 Zaragoza, Aragon (Spain); Jimenez, Pere J. [Grup Natura Freixe, Major 56, 43750 Flix, Catalonia (Spain); Munne, Antoni [Agencia Catalana de l' Aigua, Provenca 204-208, 08036 Barcelona, Catalonia (Spain); Prat, Narcis [Departament d' Ecologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona Catalonia (Spain)

    2012-02-01

    The lower Ebro River (Catalonia, Spain) has recently undergone a regime shift from a phytoplankton-dominated to a macrophyte-dominated system. This shift is well known in shallow lakes but apparently it has never been documented in rivers. Two initial hypotheses to explain the collapse of the phytoplankton were considered: a) the diminution of nutrients (bottom-up); b) the filtering effect due to the colonization of the zebra mussel (top-down). Data on water quality, hydrology and biological communities (phytoplankton, macrophytes and zebra mussel) was obtained both from existing data sets and new surveys. Results clearly indicate that the decrease in phosphorus is the main cause of a dramatic decrease in chlorophyll and large increase in water transparency, triggering the subsequent colonization of macrophytes in the river bed. A Generalized Linear Model analysis showed that the decrease in dissolved phosphorus had a relative importance 14 times higher than the increase in zebra mussel density to explain the variation of total chlorophyll. We suggest that the described changes in the lower Ebro River can be considered a novel ecosystem shift. This shift is triggering remarkable changes in the biological communities beyond the decrease of phytoplankton and the proliferation of macrophytes, such as massive colonization of Simulidae (black fly) and other changes in the benthic invertebrate communities that are currently investigated. - Highlights: Black-Right-Pointing-Pointer We show a regime shift in a large river from phytoplankton to macrophyte dominance. Black-Right-Pointing-Pointer Two main hypotheses are considered: nutrient decrease and zebra mussel grazing. Black-Right-Pointing-Pointer Phosphorus depletion is found to be the main cause of the phytoplankton decline. Black-Right-Pointing-Pointer We conclude that oligotrophication triggered the colonization of macrophytes. Black-Right-Pointing-Pointer This new regime shift in a river is similar to that described

  14. Independent effects of bottom-up temporal expectancy and top-down spatial attention. An audiovisual study using rhythmic cueing.

    Directory of Open Access Journals (Sweden)

    Alexander eJones

    2015-01-01

    Full Text Available Selective attention to a spatial location has shown enhance perception and facilitate behaviour for events at attended locations. However, selection relies not only on where but also when an event occurs. Recently, interest has turned to how intrinsic neural oscillations in the brain entrain to rhythms in our environment, and, stimuli appearing in or out of synch with a rhythm have shown to modulate perception and performance. Temporal expectations created by rhythms and spatial attention are two processes which have independently shown to affect stimulus processing but it remains largely unknown how, and if, they interact. In four separate tasks, this study investigated the effects of voluntary spatial attention and bottom-up temporal expectations created by rhythms in both unimodal and crossmodal conditions. In each task the participant used an informative cue, either colour or pitch, to direct their covert spatial attention to the left or right, and respond as quickly as possible to a target. The lateralized target (visual or auditory was then presented at the attended or unattended side. Importantly, although not task relevant, the cue was a rhythm of either flashes or beeps. The target was presented in or out of sync (early or late with the rhythmic cue. The results showed participants were faster responding to spatially attended compared to unattended targets in all tasks. Moreover, there was an effect of rhythmic cueing upon response times in both unimodal and crossmodal conditions. Responses were faster to targets presented in sync with the rhythm compared to when they appeared too early in both crossmodal tasks. That is, rhythmic stimuli in one modality influenced the temporal expectancy in the other modality, suggesting temporal expectancies created by rhythms are crossmodal. Interestingly, there was no interaction between top-down spatial attention and rhythmic cueing in any task suggesting these two processes largely influenced

  15. Effects of bottom-up and top-down intervention principles in emergent literacy in children at risk of developmental dyslexia: a longitudinal study.

    Science.gov (United States)

    Helland, Turid; Tjus, Tomas; Hovden, Marit; Ofte, Sonja; Heimann, Mikael

    2011-01-01

    This longitudinal study focused on the effects of two different principles of intervention in children at risk of developing dyslexia from 5 to 8 years old. The children were selected on the basis of a background questionnaire given to parents and preschool teachers, with cognitive and functional magnetic resonance imaging results substantiating group differences in neuropsychological processes associated with phonology, orthography, and phoneme-grapheme correspondence (i.e., alphabetic principle). The two principles of intervention were bottom-up (BU), "from sound to meaning", and top-down (TD), "from meaning to sound." Thus, four subgroups were established: risk/BU, risk/TD, control/BU, and control/TD. Computer-based training took place for 2 months every spring, and cognitive assessments were performed each fall of the project period. Measures of preliteracy skills for reading and spelling were phonological awareness, working memory, verbal learning, and letter knowledge. Literacy skills were assessed by word reading and spelling. At project end the control group scored significantly above age norm, whereas the risk group scored within the norm. In the at-risk group, training based on the BU principle had the strongest effects on phonological awareness and working memory scores, whereas training based on the TD principle had the strongest effects on verbal learning, letter knowledge, and literacy scores. It was concluded that appropriate, specific, data-based intervention starting in preschool can mitigate literacy impairment and that interventions should contain BU training for preliteracy skills and TD training for literacy training. PMID:21383104

  16. Assisted editing od SensorML with EDI. A bottom-up scenario towards the definition of sensor profiles.

    Science.gov (United States)

    Oggioni, Alessandro; Tagliolato, Paolo; Fugazza, Cristiano; Bastianini, Mauro; Pavesi, Fabio; Pepe, Monica; Menegon, Stefano; Basoni, Anna; Carrara, Paola

    2015-04-01

    -product of this ongoing work is currently constituting an archive of predefined sensor descriptions. This information is being collected in order to further ease metadata creation in the next phase of the project. Users will be able to choose among a number of sensor and sensor platform prototypes: These will be specific instances on which it will be possible to define, in a bottom-up approach, "sensor profiles". We report on the outcome of this activity.

  17. Research on ethics in two large Human Biomonitoring projects ECNIS and NewGeneris: a bottom up approach.

    Science.gov (United States)

    Dumez, Birgit; Van Damme, Karel; Casteleyn, Ludwine

    2008-01-01

    Assessment of ethical aspects and authorization by ethics committees have become a major constraint for health research including human subjects. Ethical reference values often are extrapolated from clinical settings, where emphasis lies on decisional autonomy and protection of individual's privacy. The question rises if this set of values used in clinical research can be considered as relevant references for HBM research, which is at the basis of public health surveillance. Current and future research activities using human biomarkers are facing new challenges and expectancies on sensitive socio-ethical issues. Reflection is needed on the necessity to balance individual rights against public interest. In addition, many HBM research programs require international collaboration. Domestic legislation is not always easily applicable in international projects. Also, there seem to be considerable inconsistencies in ethical assessments of similar research activities between different countries and even within one country. All this is causing delay and putting the researcher in situations in which it is unclear how to act in accordance with necessary legal requirements. Therefore, analysis of ethical practices and their consequences for HBM research is needed.This analysis will be performed by a bottom-up approach, based on a methodology for comparative analysis of determinants in ethical reasoning, allowing taking into account different social, cultural, political and historical traditions, in view of safeguarding common EU values. Based on information collected in real life complexity, paradigm cases and virtual case scenarios will be developed and discussed with relevant stakeholders to openly discuss possible obstacles and to identify options for improvement in regulation. The material collected will allow developing an ethical framework which may constitute the basis for a more harmonized and consistent socio-ethical and legal approach. This will not only increase

  18. Research on ethics in two large Human Biomonitoring projects ECNIS and NewGeneris: a bottom up approach

    Directory of Open Access Journals (Sweden)

    Casteleyn Ludwine

    2008-01-01

    Full Text Available Abstract Assessment of ethical aspects and authorization by ethics committees have become a major constraint for health research including human subjects. Ethical reference values often are extrapolated from clinical settings, where emphasis lies on decisional autonomy and protection of individual's privacy. The question rises if this set of values used in clinical research can be considered as relevant references for HBM research, which is at the basis of public health surveillance. Current and future research activities using human biomarkers are facing new challenges and expectancies on sensitive socio-ethical issues. Reflection is needed on the necessity to balance individual rights against public interest. In addition, many HBM research programs require international collaboration. Domestic legislation is not always easily applicable in international projects. Also, there seem to be considerable inconsistencies in ethical assessments of similar research activities between different countries and even within one country. All this is causing delay and putting the researcher in situations in which it is unclear how to act in accordance with necessary legal requirements. Therefore, analysis of ethical practices and their consequences for HBM research is needed. This analysis will be performed by a bottom-up approach, based on a methodology for comparative analysis of determinants in ethical reasoning, allowing taking into account different social, cultural, political and historical traditions, in view of safeguarding common EU values. Based on information collected in real life complexity, paradigm cases and virtual case scenarios will be developed and discussed with relevant stakeholders to openly discuss possible obstacles and to identify options for improvement in regulation. The material collected will allow developing an ethical framework which may constitute the basis for a more harmonized and consistent socio-ethical and legal approach

  19. Energy-environment policy modeling of endogenous technological change with personal vehicles. Combining top-down and bottom-up methods

    International Nuclear Information System (INIS)

    The transportation sector offers substantial potential for greenhouse gas (GHG) emission abatement, but widely divergent cost estimates complicate policy making; energy-economy policy modelers apply top-down and bottom-up cost definitions and different assumptions about future technologies and the preferences of firms and households. Our hybrid energy-economy policy model is technology-rich, like a bottom-up model, but has empirically estimated behavioral parameters for risk and technology preferences, like a top-down model. Unlike typical top-down models, however, it simulates technological change endogenously with functions that relate the financial costs of technologies to cumulative production and adjust technology preferences as market shares change. We apply it to the choice of personal vehicles to indicate, first, the effect on cost estimates of divergent cost definitions and, second, the possible response to policies that require a minimum market share for low emission vehicles

  20. Diagnostic study, design and implementation of an integrated model of care in France: a bottom-up process with continuous leadership

    OpenAIRE

    de Stampa, Matthieu; Vedel, Isabelle; Mauriat, Claire; Bagaragaza, Emmanuel; Routelous, Christelle; Bergman, Howard; Lapointe, Liette; Cassou, Bernard; Ankri, Joel; Henrard, Jean-Claude

    2010-01-01

    Background: Sustaining integrated care is difficult, in large part because of problems encountered securing the participation of health care and social service professionals and, in particular, general practitioners (GPs). Purpose: To present an innovative bottom-up and pragmatic strategy used to implement a new integrated care model in France for community-dwelling elderly people with complex needs.Results: In the first step, a diagnostic study was conducted with face-to-face interviews to g...

  1. Diagnostic, design and implementation of an integrated model of care in France: a bottom-up process with a continuous leadership

    OpenAIRE

    de Stampa, Matthieu; Vedel, Isabelle; Mauriat, Claire; Bagaragaza, Emmanuel; Routelous, Christelle; Bergman, Howard; Lapointe, Liette; Cassou, Bernard; Ankri, Joel; Henrard, Jean-Claude

    2010-01-01

    Purpose To present an innovative bottom-up and pragmatic strategy used to implement a new integrated care model in France for community-dwelling elderly people with complex needs. Context Sustaining integrated care is difficult, in large part because of problems encountered securing the participation of health care and social service professionals and, in particular, general practitioners (GPs). Case description In the first step, a diagnostic study was conducted with face-to-face interviews ...

  2. "Disorganized in time": Impact of bottom-up and top-down negative emotion generation on memory formation among healthy and traumatized adolescents.

    OpenAIRE

    Guillery-Girard, Bérengère; Clochon, Patrice; Giffard, Bénédicte; Viard, Armelle; Egler, Pierre-Jean; Baleyte, Jean-Marc; Eustache, Francis; Dayan, Jacques

    2013-01-01

    International audience "Travelling in time," a central feature of episodic memory is severely affected among individuals with Post Traumatic Stress Disorder (PTSD) with two opposite effects: vivid traumatic memories are unorganized in temporality (bottom-up processes), non-traumatic personal memories tend to lack spatio-temporal details and false recognitions occur more frequently that in the general population (top-down processes). To test the effect of these two types of processes (i.e. ...

  3. Synthesis of a Cementitious Material Nanocement Using Bottom-Up Nanotechnology Concept: An Alternative Approach to Avoid CO2 Emission during Production of Cement

    OpenAIRE

    Byung Wan Jo; Sumit Chakraborty; Kwang Won Yoon

    2014-01-01

    The world’s increasing need is to develop smart and sustainable construction material, which will generate minimal climate changing gas during their production. The bottom-up nanotechnology has established itself as a promising alternative technique for the production of the cementitious material. The present investigation deals with the chemical synthesis of cementitious material using nanosilica, sodium aluminate, sodium hydroxide, and calcium nitrate as reacting phases. The characteristic ...

  4. Influence of the adding bottom-up flow rate to the characteristic of the cooling system on TRIGA 2000 Bandung reactor core

    International Nuclear Information System (INIS)

    Heat generated from the fission reaction will heat up the cladding of the fuel element. For this reason, the fluid which used as a primary coolant in the reactor tank must have a good conductivity. This research is done to know the comparison between the performance of the natural convection cooling system and the performance of the forced convection cooling system which is done by spraying the bottom-up flow rate to the cylindrical nuclear reactor core. The result shows that the forced convection by adding spray pipe has a better performance than that of the natural convection. This case is indicated by decreasing of the maximum temperature on the top of the reactor core from 88,55°C to 47,35°C after the adding bottom-up flow rate. It can be assumed that the adding of the spraying bottom-up flow rate will give a better performance on the cooling system and will reduce the bubbles formation. (author)

  5. Modeling technical change in energy system analysis: analyzing the introduction of learning-by-doing in bottom-up energy models

    International Nuclear Information System (INIS)

    The main objective of this paper is to provide an overview and a critical analysis of the recent literature on incorporating induced technical change in energy systems models. Special emphasis is put on surveying recent studies aimed at integrating learning-by-doing into bottom-up energy systems models through so-called learning curves, and on analyzing the relevance of learning curve analysis for understanding the process of innovation and technology diffusion in the energy sector. The survey indicates that this model work represents a major advance in energy research, and embeds important policy implications, not the least concerning the cost and the timing of environmental policies (including carbon emission constraints). However, bottom-up energy models with endogenous learning are also limited in their characterization of technology diffusion and innovation. While they provide a detailed account of technical options-which is absent in many top-down models-they also lack important aspects of diffusion behavior that are captured in top-down representations. For instance, they often fail in capturing strategic technology diffusion behavior in the energy sector as well as the energy sector's endogenous responses to policy, and they neglect important general equilibrium impacts (such as the opportunity cost of redirecting R and D support to the energy sector). Some suggestions on how innovation and diffusion modeling in bottom-up analysis can be improved are put forward

  6. Will ESD reporting using bottom-up energy savings calculations be a nightmare or the next step in a better understanding of national energy savings?

    Energy Technology Data Exchange (ETDEWEB)

    Vreuls, Harry; Both, Dick (SenterNovem, The Hague (Netherlands)); Thomas, Stefan (Wuppertal Institute for Climate Environment Energy, Wuppertal (Germany)); Broc, Jean-Sebastien (Ecole des Mines de Nantes (France))

    2009-07-01

    The ESD (Energy Services Directive) requires that EU Member States increase their use of bottom-up energy savings calculations to report on the results of their energy efficiency policies. To make the results more comparable over the Member States harmonised methods should be developed and improved. The first experiences with this harmonisation process from the EMEEES project are presented in this paper. It starts with the introduction of the areas that could be dealt with in the harmonisation: the policies and measures, the individual appliances and installations and the aggregation level of a building, a company or an organisation. Each of them has its own characteristics and complexity to handle with. Some case applications (Voluntary Agreements, Energy Audits, Boilers and Building envelope of existing buildings) for bottom up energy savings calculations are presented to illustrate this. But if harmonisation should be realised for all these levels and economic sectors (industry, agriculture, transport, commercial and non-commercial services and households) it would results in thousands of pages with instructions. This would be a nightmare, but is there another way to reach improved harmonisation? The paper argues on what key elements the harmonisation should concentrate: a general structure for documentation of bottom-up energy savings, the selection of baseline and baseline parameters, and a dynamic approach to ensure improvement over time.

  7. Modeling Technical Change in Energy System Analysis: Analyzing the Introduction of Learning-by-Doing in Bottom-up Energy Models

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Christer; Soederholm, Patrik [Luleaa Univ. of Technology (Sweden). Div. of Economics

    2005-02-01

    The main objective of this paper is to provide an overview and a critical analysis of the recent literature on incorporating induced technical change in energy systems models. Special emphasis is put on surveying recent studies aiming at integrating learning-by-doing into bottom-up energy systems models through so-called learning curves, and on analyzing the relevance of learning curve analysis for understanding the process of innovation and technology diffusion in the energy sector. The survey indicates that this model work represents a major advance in energy research, and embeds important policy implications, not the least concerning the cost and the timing of environmental policies (including carbon emission constraints). However, bottom-up energy models with endogenous learning are also limited in their characterization of technology diffusion and innovation. While they provide a detailed account of technical options - which is absent in many top-down models - they also lack important aspects of diffusion behavior that are captured in top-down representations. For instance, they fail in capturing strategic technology diffusion behavior in the energy sector, and they neglect important general equilibrium impacts (such as the opportunity cost of redirecting R and D support to the energy sector). For these reasons bottom-up and top-down models with induced technical change should not be viewed as substitutes but rather as complements.

  8. Application of the 'bottom up' approach for the predictive modeling of sorption isotherms on Hungarian Boda clay

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. Argillaceous rocks are being viewed with continuing interest in many waste management programmes as suitable host formations for the deep geological disposal of radioactive waste: Opalinus clay, Switzerland; Boom and Ypresian clays, Belgium, Callovo-Oxfordian clays, France. One of the options for disposal of radioactive waste in Hungary is the storage in the Boda Clay-stone Formation (BCF). Clay minerals such as illite, smectite, illite/smectite mixed layers and kaolinite are important components in such rock types and can often make up 50 or more wt.% of the total mass. Predicting the fate and transport of radionuclides (RNs) in the repository near- and far-fields is a key research issue in many radioactive waste management programmes, and is one of the main pillars upon which the safety cases for deep geological radioactive waste repositories are built. A broad variety of different types of sorption models i.e. empirical and mechanistic have been developed over the past few decades to describe the interaction of RNs at the clay-water interface over a wide range of conditions. Sorption edges and isotherms were measured for a large number of radionuclides with valences from II to VI on illite and montmorillonite and could be very well described by a relatively simple model, the 2 site proto-lysis non-electrostatic surface complexation and cation exchange (2SPNE SC/CE) sorption model. Cs sorption on illite was modelled in the past and was further developed to a generalised Cs sorption model. Sorption in most natural argillaceous rocks is inherently too complex and multi-faceted to be directly understood in terms of mechanisms and their associated parameters. The so-called 'bottom up' approach is based on the hypothesis that the uptake of RNs in complex mineral/groundwater systems can be quantitatively predicted from the understanding of the sorption processes on single minerals, and the models developed to describe

  9. HPLC bottom-up MS-based proteomics for mapping of specific proteins in several European spring barley varieties

    Czech Academy of Sciences Publication Activity Database

    Flodrová, Dana; Benkovská, Dagmar; Laštovičková, Markéta; Bobálová, Janette

    2015-01-01

    Roč. 73, č. 1 (2015), s. 71-77. ISSN 0361-0470 R&D Projects: GA ČR(CZ) GPP503/12/P395 Institutional support: RVO:68081715 Keywords : barley * gel electrophoresis * MALDI-TOF/TOF MS * protein profile * RP liquid chromatography Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.886, year: 2014

  10. A bottom-up method to develop pollution abatement cost curves for coal-fired utility boilers

    International Nuclear Information System (INIS)

    This paper illustrates a new method to create supply curves for pollution abatement using boiler-level data that explicitly accounts for technology cost and performance. The Coal Utility Environmental Cost (CUECost) model is used to estimate retrofit costs for five different NOx control configurations on a large subset of the existing coal-fired, utility-owned boilers in the US. The resultant data are used to create technology-specific marginal abatement cost curves (MACCs) and also serve as input to an integer linear program, which minimizes system-wide control costs by finding the optimal distribution of NOx controls across the modeled boilers under an emission constraint. The result is a single optimized MACC that accounts for detailed, boiler-specific information related to NOx retrofits. Because the resultant MACCs do not take into account regional differences in air-quality standards or pre-existing NOx controls, the results should not be interpreted as a policy prescription. The general method as well as NOx-specific results presented here should be of significant value to modelers and policy analysts who must estimate the costs of pollution reduction.

  11. Increased water salinity applied to tomato plants accelerates the development of the leaf miner Tuta absoluta through bottom-up effects.

    Science.gov (United States)

    Han, Peng; Wang, Zhi-Jian; Lavoir, Anne-Violette; Michel, Thomas; Seassau, Aurélie; Zheng, Wen-Yan; Niu, Chang-Ying; Desneux, Nicolas

    2016-01-01

    Variation in resource inputs to plants may trigger bottom-up effects on herbivorous insects. We examined the effects of water input: optimal water vs. limited water; water salinity: with vs. without addition of 100 mM NaCl; and their interactions on tomato plants (Solanum lycopersicum), and consequently, the bottom-up effects on the tomato leaf miner, Tuta absoluta (Meytick) (Lepidoptera: Gelechiidae). Plant growth was significantly impeded by limited water input and NaCl addition. In terms of leaf chemical defense, the production of tomatidine significantly increased with limited water and NaCl addition, and a similar but non-significant trend was observed for the other glycoalkaloids. Tuta absoluta survival did not vary with the water and salinity treatments, but the treatment "optimal water-high salinity" increased the development rate without lowering pupal mass. Our results suggest that caution should be used in the IPM program against T. absoluta when irrigating tomato crops with saline water. PMID:27619473

  12. Identifying Bottom-Up and Top-Down Components of Attentional Weight by Experimental Analysis and Computational Modeling

    DEFF Research Database (Denmark)

    Nordfang, Maria; Dyrholm, Mads; Bundesen, Claus

    2013-01-01

    stimuli but unspeeded responses. The task was to report the letters from a mixture of letters (targets) and digits (distractors). Color was irrelevant to the task, but many stimulus displays contained an item (target or distractor) in a deviant color (a color singleton). The results showed concurrent....... Measured by use of Bundesen’s (1990) computational theory of visual attention, the attentional weight of a singleton object was nearly proportional to the weight of an otherwise similar nonsingleton object, with a factor of proportionality that increased with the strength of the feature contrast of the...

  13. Changes in Stiffness of Resin-infiltrated Demineralized Dentin after Remineralization with a Bottom-up Biomimetic Approach

    OpenAIRE

    Gu, Li-Sha; Huffman, Bradford P.; Arola, Dwayne D.; Kim, Young Kyung; Mai, Sui; Elsalanty, Mohammed E.; PASHLEY David H.; Franklin R Tay

    2009-01-01

    This study examined changes in elastic modulus, mineral density and ultrastructure of resin-infiltrated dentin after biomimetic remineralization. Sixty demineralized dentin beams were infiltrated with Clearfil Tri-S Bond, One-Step or Prime&Bond NT. They were immersed in simulated body fluid (SBF) for one week to maximize water sorption before determining the baseline elastic moduli. For each adhesive (N=20), half of the beams remained immersed in SBF (control). The rest were immersed in a bio...

  14. A new bottom-up methodology to produce silicon layers with a closed porosity nanostructure and reduced refractive index.

    Science.gov (United States)

    Godinho, V; Caballero-Hernández, J; Jamon, D; Rojas, T C; Schierholz, R; García-López, J; Ferrer, F J; Fernández, A

    2013-07-12

    A new approach is presented to produce amorphous porous silicon coatings (a-pSi) with closed porosity by magnetron sputtering of a silicon target. It is shown how the use of He as the process gas at moderated power (50-150 W RF) promotes the formation of closed nanometric pores during the growth of the silicon films. The use of oblique-angle deposition demonstrates the possibility of aligning and orientating the pores in one direction. The control of the deposition power allows the control of the pore size distribution. The films have been characterized by a variety of techniques, including scanning and transmission electron microscopy, electron energy loss spectroscopy, Rutherford back scattering and x-ray photoelectron spectroscopy, showing the incorporation of He into the films (most probably inside the closed pores) and limited surface oxidation of the silicon coating. The ellipsometry measurements show a significant decrease in the refractive index of porous coatings (n(500 nm) = 3.75) in comparison to dense coatings (n(500 nm) = 4.75). The capability of the method to prepare coatings with a tailored refractive index is therefore demonstrated. The versatility of the methodology is shown in this paper by preparing intrinsic or doped silicon and also depositing (under DC or RF discharge) a-pSi films on a variety of substrates, including flexible materials, with good chemical and mechanical stability. The fabrication of multilayers of silicon films of controlled refractive index in a simple (one-target chamber) deposition methodology is also presented. PMID:23764615

  15. A new bottom-up methodology to produce silicon layers with a closed porosity nanostructure and reduced refractive index

    International Nuclear Information System (INIS)

    A new approach is presented to produce amorphous porous silicon coatings (a-pSi) with closed porosity by magnetron sputtering of a silicon target. It is shown how the use of He as the process gas at moderated power (50–150 W RF) promotes the formation of closed nanometric pores during the growth of the silicon films. The use of oblique-angle deposition demonstrates the possibility of aligning and orientating the pores in one direction. The control of the deposition power allows the control of the pore size distribution. The films have been characterized by a variety of techniques, including scanning and transmission electron microscopy, electron energy loss spectroscopy, Rutherford back scattering and x-ray photoelectron spectroscopy, showing the incorporation of He into the films (most probably inside the closed pores) and limited surface oxidation of the silicon coating. The ellipsometry measurements show a significant decrease in the refractive index of porous coatings (n500 nm = 3.75) in comparison to dense coatings (n500 nm = 4.75). The capability of the method to prepare coatings with a tailored refractive index is therefore demonstrated. The versatility of the methodology is shown in this paper by preparing intrinsic or doped silicon and also depositing (under DC or RF discharge) a-pSi films on a variety of substrates, including flexible materials, with good chemical and mechanical stability. The fabrication of multilayers of silicon films of controlled refractive index in a simple (one-target chamber) deposition methodology is also presented. (paper)

  16. Modeling eye movements in visual agnosia with a saliency map approach: bottom-up guidance or top-down strategy?

    Science.gov (United States)

    Foulsham, Tom; Barton, Jason J S; Kingstone, Alan; Dewhurst, Richard; Underwood, Geoffrey

    2011-08-01

    Two recent papers (Foulsham, Barton, Kingstone, Dewhurst, & Underwood, 2009; Mannan, Kennard, & Husain, 2009) report that neuropsychological patients with a profound object recognition problem (visual agnosic subjects) show differences from healthy observers in the way their eye movements are controlled when looking at images. The interpretation of these papers is that eye movements can be modeled as the selection of points on a saliency map, and that agnosic subjects show an increased reliance on visual saliency, i.e., brightness and contrast in low-level stimulus features. Here we review this approach and present new data from our own experiments with an agnosic patient that quantifies the relationship between saliency and fixation location. In addition, we consider whether the perceptual difficulties of individual patients might be modeled by selectively weighting the different features involved in a saliency map. Our data indicate that saliency is not always a good predictor of fixation in agnosia: even for our agnosic subject, as for normal observers, the saliency-fixation relationship varied as a function of the task. This means that top-down processes still have a significant effect on the earliest stages of scanning in the setting of visual agnosia, indicating severe limitations for the saliency map model. Top-down, active strategies-which are the hallmark of our human visual system-play a vital role in eye movement control, whether we know what we are looking at or not. PMID:21316191

  17. Computational Nano-materials Design for Spinodal Nanotechnology as a New Class of Bottom-up Nanotechnology

    Science.gov (United States)

    Katayama-Yoshida, Hiroshi; Fukushima, Tetsuya; Sato, Kazunori

    Based on the spinodal nano-decomposition (SND) of dilute magnetic semiconductors (DMS), we generalized the SND to the application of catalysis and photovoltaic solar-cells, where nano-scale particle formation in catalysis and and nano-scale separation of electrons and holes are essential in order to enhance the efficiency. First, we summarize the shape control (Konbu- & Dairiseki-Phases) and dimensionality dependence of crystal growth condition on SND in DMS. Second, we discuss the application of SND for the formation of nano-particles and the self-regeneration in three-way catalysis for automotive emission control by Perovskite La(Fe,Pd or Rh)O3. Third, we propose (i) self-regeneration mechanism and (ii) self-organized nano-structures by SND in chalcopyrite Cu(In,Ga)Se2, Kesterite Cu2ZnSnSe4, and Perovskite CsSnI3 for the low-cost, environment-friendly and high-efficiency photovoltaic solar cells using first-principles calculations.

  18. From the bottom up: tracing the impact of four health-based social movements on health and social policies.

    Science.gov (United States)

    Keefe, Robert H; Lane, Sandra D; Swarts, Heidi J

    2006-01-01

    Although health-based social movements organized by grassroots activists have a rich history in impacting health and social policy, few systematic studies have addressed their policy change efforts or effectiveness. In this article, the authors trace how four health-based social movements-the women's health movement, ACT UP, breast cancer, and needle exchange-influenced health and social policy legislation. The activists' efforts wrested control of "authoritative knowledge" that had once been the sole domain of "experts" with advanced medical training. They used this knowledge to empower "average" people with medical information, promote self help and engage in civil disobedience, which led to changes in healthcare delivery, drug testing and approval, and increased research funds for HIV/AIDS, breast cancer, and needle exchange. The activists' efforts led to other health-based social movements that are currently, or will become, issues for health and social policy analysts in the future. PMID:16635945

  19. Bottom-up resource limitation: the ecosystem energy balance predicts the quality of nutrition in a herbivore prey population

    DEFF Research Database (Denmark)

    Fernandez, Nestor; Garcia, Monica; Gil, Esperanza;

    2014-01-01

    Vegetation greenness indices from remote sensing are increasingly used in population ecology studies assuming that land surface reflectance can reflect the availability of nutritional resources for primary consumers. However, the relationship between these indices and the characteristics of the...... herbivore diet has been insufficiently tested. We hypothesized that in drylands, where water availability is a prime control of ecosystem functioning, remote sensing indicators of vegetation drought stress are critical to predict the nutritional quality of herbivore habitats. This hypothesis was analyzed by...... allowed us to characterize the overall quality of each habitat and to relate it with rabbit abundance. Results have far-reaching implications for assessing habitat quality and the effects of functional ecosystem changes on a keystone prey herbivore and associated communities....

  20. A bottom-up perspective of the net land methanol flux: synthesis of global eddy covariance flux measurements

    Science.gov (United States)

    Wohlfahrt, Georg; Amelynck, Crist; Ammann, Christof; Arneth, Almut; Bamberger, Ines; Goldstein, Allen; Hansel, Armin; Heinesch, Bernhard; Holst, Thomas; Hörtnagl, Lukas; Karl, Thomas; Neftel, Albrecht; McKinney, Karena; Munger, William; Schade, Gunnar; Schoon, Niels

    2014-05-01

    Methanol (CH3OH) is, after methane, the second most abundant VOC in the troposphere and globally represents nearly 20% of the total biospheric VOC emissions. With typical concentrations of 1-10 ppb in the continental boundary layer, methanol plays a crucial role in atmospheric chemistry, which needs to be evaluated in the light of ongoing changes in land use and climate. Previous global methanol budgets have approached the net land flux by summing up the various emission terms (namely primary biogenic and anthropogenic emissions, plant decay and biomass burning) and by subtracting dry and wet deposition, resulting in a net land flux in the range of 75-245 Tg y-1. The data underlying these budget calculations largely stem from small-scale leaf gas exchange measurements and while recently column-integrated remotely sensed methanol concentrations have become available for constraining budget calculations, there have been few attempts to contrast model calculations with direct net ecosystem-scale methanol flux measurements. Here we use eddy covariance methanol flux measurements from 8 sites in Europe and North America to study the magnitude of and controls on the diurnal and seasonal variability in the net ecosystem methanol flux. In correspondence with leaf-level literature, our data show that methanol emission and its strong environmental and biotic control (by temperature and stomatal conductance) prevailed at the more productive (agricultural) sites and at a perturbed forest site. In contrast, at more natural, less productive sites substantial deposition of methanol occurred, in particular during periods of surface wetness. These deposition processes are poorly represented by currently available temperature/light and/or production-driven modelling algorithms. A new framework for modelling the bi-directional land-atmosphere methanol exchange is proposed which accounts for the production of methanol in leaves, the regulation of leaf methanol emission by stomatal

  1. An Extended Model for the Evolution of Prebiotic Homochirality: A Bottom-Up Approach to the Origin of Life

    CERN Document Server

    Gleiser, Marcelo

    2008-01-01

    A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction rates $\\epsilon_L$ and $\\epsilon_R$, respectively. The spatiotemporal evolution of the net chiral asymmetry is studied for models with several values of the maximum polymer length, N. For N=2, we study the validity of the adiabatic approximation often cited in the literature. We show that the approximation obtains the correct equilibrium values of the net chirality, but fails to reproduce the short time behavior. We show also that the autogenic term in the full N=2 model behaves as a control parameter in a chiral symmetry- breaking phase transition leading to full homochirality from racemic initial conditions. We study the dynamics of the N -> infinity model with symmetric ($\\epsilon_L = \\epsilon_R$) autogenic formation, showing that it only achieves homochir...

  2. A bottom-up art event gave birth to a process of community empowerment in an Italian village.

    Science.gov (United States)

    Sardu, Claudia; Mereu, Alessandra; Sotgiu, Alessandra; Contu, Paolo

    2012-03-01

    Although community participation is a component of community empowerment, it often remains a theoretical exhortation. Reporting experiences which enable people to take control of their lives, can be useful to suggest practical elements for promoting empowerment. This article describes the experience of a Sardinian village (Ulassai), that developed into a community empowerment. The Laverack's operational domains were used to measure the community empowerment process. The process started in 1979 'almost by chance' with an art performance that was the entry point for community participation. This experience has been the foundation for the community empowerment. Citizens acquired the 'ability of thinking and planning as a community and not mere individuals'. In the following 30 years citizens gave birth to several outcomes rooted in that event. The intermediate outcomes highlight the 'ability of action by a group to mobilize existing resources, and act collectively against opposing forces'. The long-term outcomes demonstrate the 'ability to integrate the cultural experiences that strengthened the community's identification into a sustainable community asset', and the 'ability to cope with global environmental challenges and to collaborate on an equal basis with other stakeholders. The pathways to community empowerment, showed by the community of Ulassai, overlap with the 'operational domains'. The Ulassai experience shows that the empowerment process can start from an event apparently unrelated to health promotion. This community experience illustrates the positive role arts can play in community development. Hence, the call for health promoters to look carefully into those situations that occur naturally in communities. PMID:24801310

  3. Hierarchical three-dimensional microbattery electrodes combining bottom-up self-assembly and top-down micromachining.

    Science.gov (United States)

    Gerasopoulos, Konstantinos; Pomerantseva, Ekaterina; McCarthy, Matthew; Brown, Adam; Wang, Chunsheng; Culver, James; Ghodssi, Reza

    2012-07-24

    The realization of next-generation portable electronics and integrated microsystems is directly linked with the development of robust batteries with high energy and power density. Three-dimensional micro- and nanostructured electrodes enhance energy and power through higher surface area and thinner active materials, respectively. Here, we present a novel approach for the fabrication of hierarchical electrodes that combine benefits of both length scales. The electrodes consist of self-assembled, virus-templated nanostructures conformally coating three-dimensional micropillars. Active battery material (V(2)O(5)) is deposited using atomic layer deposition on the hierarchical micro/nanonetwork. Electrochemical characterization of these electrodes indicates a 3-fold increase in energy density compared to nanostructures alone, in agreement with the surface area increase, while maintaining the high power characteristics of nanomaterials. Investigation of capacity scaling for varying active material thickness reveals underlying limitations in nanostructured electrodes and highlights the importance of our method in controlling both energy and power density with structural hierarchy. PMID:22670634

  4. An extended model for the evolution of prebiotic homochirality: a bottom-up approach to the origin of life.

    Science.gov (United States)

    Gleiser, Marcelo; Walker, Sara Imari

    2008-08-01

    A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction rates epsilon L and epsilon R, respectively. The spatiotemporal evolution of the net chiral asymmetry is studied for models with several values of the maximum polymer length, N. For N = 2, we study the validity of the adiabatic approximation often cited in the literature. We show that the approximation obtains the correct equilibrium values of the net chirality, but fails to reproduce the short time behavior. We show also that the autogenic term in the full N = 2 model behaves as a control parameter in a chiral symmetry-breaking phase transition leading to full homochirality from racemic initial conditions. We study the dynamics of the N--> infinity model with symmetric (epsilon L = epsilon R) autogenic formation, showing that it only achieves homochirality for epsilon > epsilon c, where epsilon c is an N-dependent critical value. For epsilon

  5. Toward consistency between bottom-up CO2 emissions trends and top-down atmospheric measurements in the Los Angeles megacity

    Science.gov (United States)

    Newman, S.; Xu, X.; Gurney, K. R.; Hsu, Y.-K.; Li, K.-F.; Jiang, X.; Keeling, R.; Feng, S.; O'Keefe, D.; Patarasuk, R.; Wong, K. W.; Rao, P.; Fischer, M. L.; Yung, Y. L.

    2015-10-01

    Large urban emissions of greenhouse gases result in large atmospheric enhancements relative to background that are easily measured. Using CO2 mole fractions and Δ14C and δ13C values of CO2 in the Los Angeles megacity observed in inland Pasadena (2006-2013) and coastal Palos Verdes peninsula (autumn 2009-2013), we have determined time series for CO2 contributions from fossil fuel combustion for both sites and broken those down into contributions from petroleum/gasoline and natural gas burning for Pasadena. We find a 10 % reduction in Pasadena CO2 emissions from fossil fuel combustion during the Great Recession of 2008-2010, which is consistent with the bottom-up inventory determined by the California Air Resources Board. The isotopic variations and total atmospheric CO2 from our observations are used to infer seasonality of natural gas and petroleum combustion. For natural gas, inferred emissions are out of phase with the seasonal cycle of total natural gas combustion seasonal patterns in bottom-up inventories but are consistent with the seasonality of natural gas usage by the area's electricity generating power plants. For petroleum, the inferred seasonality of CO2 emissions from burning petroleum is delayed by several months relative to usage indicated by statewide gasoline taxes. Using the high-resolution Hestia-LA data product to compare emissions from parts of the basin sampled by winds at different times of year, we find that variations in observed fossil fuel CO2 reflect seasonal variations in wind direction. The seasonality of the local CO2 excess from fossil fuel combustion along the coast, on Palos Verdes peninsula, is higher in fall and winter than spring and summer, almost completely out of phase with that from Pasadena, also because of the annual variations of winds in the region. Variations in fossil fuel CO2 signals are consistent with sampling the bottom-up Hestia-LA fossil CO2 emissions product for sub-city source regions in the LA megacity domain

  6. Toward consistency between trends in bottom-up CO2 emissions and top-down atmospheric measurements in the Los Angeles megacity

    Science.gov (United States)

    Newman, Sally; Xu, Xiaomei; Gurney, Kevin R.; Kuang Hsu, Ying; Li, King Fai; Jiang, Xun; Keeling, Ralph; Feng, Sha; O'Keefe, Darragh; Patarasuk, Risa; Weng Wong, Kam; Rao, Preeti; Fischer, Marc L.; Yung, Yuk L.

    2016-03-01

    Large urban emissions of greenhouse gases result in large atmospheric enhancements relative to background that are easily measured. Using CO2 mole fractions and Δ14C and δ13C values of CO2 in the Los Angeles megacity observed in inland Pasadena (2006-2013) and coastal Palos Verdes peninsula (autumn 2009-2013), we have determined time series for CO2 contributions from fossil fuel combustion (Cff) for both sites and broken those down into contributions from petroleum and/or gasoline and natural gas burning for Pasadena. We find a 10 % reduction in Pasadena Cff during the Great Recession of 2008-2010, which is consistent with the bottom-up inventory determined by the California Air Resources Board. The isotopic variations and total atmospheric CO2 from our observations are used to infer seasonality of natural gas and petroleum combustion. The trend of CO2 contributions to the atmosphere from natural gas combustion is out of phase with the seasonal cycle of total natural gas combustion seasonal patterns in bottom-up inventories but is consistent with the seasonality of natural gas usage by the area's electricity generating power plants. For petroleum, the inferred seasonality of CO2 contributions from burning petroleum is delayed by several months relative to usage indicated by statewide gasoline taxes. Using the high-resolution Hestia-LA data product to compare Cff from parts of the basin sampled by winds at different times of year, we find that variations in observed fossil fuel CO2 reflect seasonal variations in wind direction. The seasonality of the local CO2 excess from fossil fuel combustion along the coast, on Palos Verdes peninsula, is higher in autumn and winter than spring and summer, almost completely out of phase with that from Pasadena, also because of the annual variations of winds in the region. Variations in fossil fuel CO2 signals are consistent with sampling the bottom-up Hestia-LA fossil CO2 emissions product for sub-city source regions in the LA

  7. Deciphering the components of regional net ecosystem fluxes following a bottom-up approach for the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    N. Carvalhais

    2010-06-01

    Full Text Available Quantification of ecosystem carbon pools is a fundamental requirement for estimating carbon fluxes and for addressing the dynamics and responses of the terrestrial carbon cycle to environmental drivers. The initial estimates of carbon pools in terrestrial carbon cycle models often rely on the ecosystem steady state assumption, leading to initial equilibrium conditions. In this study, we investigate how trends and inter-annual variability of net ecosystem fluxes are affected by initial non-steady state conditions. Further, we examine how modeled ecosystem responses induced exclusively by the model drivers can be separated from the initial conditions. For this, the Carnegie-Ames-Stanford Approach (CASA model is optimized at set of European eddy covariance sites, which support the parameterization of regional simulations of ecosystem fluxes for the Iberian Peninsula, between 1982 and 2006.

    The presented analysis stands on a credible model performance for a set of sites, that well represent the plant functional types and selected descriptors of climate and phenology present in the Iberian region – except for a limited northwestern area. The effects of initial conditions on inter-annual variability and on trends, results mostly from the recovery of pools to equilibrium conditions; which control most of the inter-annual variability (IAV and both the magnitude and sign of most of the trends. However, by removing the time series of pure model recovery from the time series of the overall fluxes, we are able to retrieve estimates of inter-annual variability and trends in net ecosystem fluxes that are quasi-independent from the initial conditions. This approach reduced the sensitivity of the net fluxes to initial conditions from 47% and 174% to −3% and 7%, for strong initial sink and source conditions, respectively.

    With the aim to identify and improve understanding of the component fluxes that drive the observed trends, the net

  8. Deciphering the components of regional net ecosystem fluxes following a bottom-up approach for the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    N. Carvalhais

    2010-11-01

    Full Text Available Quantification of ecosystem carbon pools is a fundamental requirement for estimating carbon fluxes and for addressing the dynamics and responses of the terrestrial carbon cycle to environmental drivers. The initial estimates of carbon pools in terrestrial carbon cycle models often rely on the ecosystem steady state assumption, leading to initial equilibrium conditions. In this study, we investigate how trends and inter-annual variability of net ecosystem fluxes are affected by initial non-steady state conditions. Further, we examine how modeled ecosystem responses induced exclusively by the model drivers can be separated from the initial conditions. For this, the Carnegie-Ames-Stanford Approach (CASA model is optimized at set of European eddy covariance sites, which support the parameterization of regional simulations of ecosystem fluxes for the Iberian Peninsula, between 1982 and 2006.

    The presented analysis stands on a credible model performance for a set of sites, that represent generally well the plant functional types and selected descriptors of climate and phenology present in the Iberian region – except for a limited Northwestern area. The effects of initial conditions on inter-annual variability and on trends, results mostly from the recovery of pools to equilibrium conditions; which control most of the inter-annual variability (IAV and both the magnitude and sign of most of the trends. However, by removing the time series of pure model recovery from the time series of the overall fluxes, we are able to retrieve estimates of inter-annual variability and trends in net ecosystem fluxes that are quasi-independent from the initial conditions. This approach reduced the sensitivity of the net fluxes to initial conditions from 47% and 174% to −3% and 7%, for strong initial sink and source conditions, respectively.

    With the aim to identify and improve understanding of the component fluxes that drive the observed trends, the

  9. The synthesis of bottom-up and top-down approaches to climate policy modeling: Electric power technology detail in a social accounting framework

    International Nuclear Information System (INIS)

    ''Hybrid'' climate policy simulations have sought to bridge the gap between ''bottom-up'' engineering and ''top-down'' macroeconomic models by integrating the former's energy technology detail into the latter's macroeconomic framework. Construction of hybrid models is complicated by the need to numerically calibrate them to multiple, incommensurate sources of economic and engineering data. I develop a solution to this problem following Howitt's [Howitt, R.E., 1995. Positive Mathematical Programming, American Journal of Agricultural Economics 77: 329-342] positive mathematical programming approach. Using data for the U.S., I illustrate how the inputs to the electricity sector in a social accounting matrix may be allocated among discrete types of generation so as to be consistent with both technologies' input shares from engineering cost estimates, and the zero profit and market clearance conditions of the sector's macroeconomic production structure. (author)

  10. A convenient two-step bottom-up approach for developing Au/Fe{sub 3}O{sub 4} nanocomposites with useful optical and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Amala Jayanthi, S. [Department of Physics, Government Arts College (Autonomous), Nandanam, Chennai 600035 (India); Manovah David, T. [Department of Chemistry, Madras Christian College (Autonomous), Chennai 600059 (India); Jayashainy, J.; Muthu Gnana Theresa Nathan, D. [Department of Physics, Loyola College (Autonomous), Chennai 600034 (India); Sagayaraj, P., E-mail: psagayaraj@hotmail.com [Department of Physics, Loyola College (Autonomous), Chennai 600034 (India)

    2014-09-01

    Graphical abstract: Au/Fe{sub 3}O{sub 4} nanocomposites were successfully synthesized using a two-step bottom up approach under co-precipitation followed by solvothermal synthesis without using capping agents or additives. TEM results indicate that nanocomposites with less agglomeration and high monodispersion can be obtained even in the absence of additives or capping ligands. - Highlights: • Au/Fe{sub 3}O{sub 4} nanocomposites without using additives, mediator or capping ligands. • Surface morphology study reveals the uniform AuNPs coating in the nanocomposites. • Soft ferromagnetic behavior with larger M{sub s} values is observed at room temperature. - Abstract: A convenient two-step bottom-up approach is reported for the preparation of Au/Fe{sub 3}O{sub 4} nanocomposites. The synthesis of Fe{sub 3}O{sub 4} was achieved by co-precipitation method and rapid synthesis procedure was adopted for forming Au nanoparticles. The solutions containing the Fe{sub 3}O{sub 4} and Au nanoparticles were mixed in two different ratios and then solvothermally treated to obtain the Au/Fe{sub 3}O{sub 4} nanocomposites. The structural and optical properties of the nanocomposites were investigated by powder X-ray diffraction and optical absorption spectroscopic techniques. The field emission scanning electron microscopy pictures illustrate the surface morphology of the as-prepared nanocomposites. The energy dispersive X-ray analysis spectrum was taken to estimate the exact percentage of elemental composition of the nanopowder. The transmission electron microscopy analysis of the nanocomposites confirmed the presence and morphology of the Au and Fe{sub 3}O{sub 4} nanoparticles. The Au/Fe{sub 3}O{sub 4} nanocomposites were found to exhibit soft ferromagnetic behavior.

  11. Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

    Directory of Open Access Journals (Sweden)

    W. J. F. Acton

    2015-10-01

    Full Text Available This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton transfer reaction-mass spectrometer (PTR-MS and a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS together with the methods of virtual disjunct eddy covariance (PTR-MS and eddy covariance (PTR-ToF-MS. Isoprene was the dominant emitted compound with a mean day-time flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28 day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the MEGAN isoprene emissions algorithms (Guenther et al., 2006. A detailed tree species distribution map for the site enabled the leaf-level emissions of isoprene and monoterpenes recorded using GC-MS to be scaled up to produce a "bottom-up" canopy-scale flux. This was compared with the "top-down" canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

  12. Heat recovery with heat pumps in non-energy intensive industry: A detailed bottom-up model analysis in the French food and drink industry

    International Nuclear Information System (INIS)

    Highlights: • First bottom-up energy model for NEI at 4-digit level of NACE for energy analysis. • Energy end-use modelling due to the unsuitability of end-product/process approach. • Analysis of heat recovery with HP on industrial processes up to 2020 in French F and D. • Energy consumption and emissions drop respectively by 10% compared to 2001 and 9% to 1990. • Results only achieved at heat temperature below 100 °C, concentrated in 1/3 of F and D sectors. - Abstract: Rising energy prices and environmental impacts inevitably encourage industrials to get involved in promoting energy efficiency and emissions reductions. To achieve this goal, we have developed the first detailed bottom-up energy model for Non-Energy Intensive industry (NEI) to study its global energy efficiency and the potential for CO2 emissions reduction at a 4-digit level of NACE classification. The latter, which is generally neglected in energy analyses, is expected to play an important role in reducing industry energy intensity in the long term due to its economic and energy significance and relatively high growth rate. In this paper, the modelling of NEI is done by energy end-use owing to the unsuitability of the end-product/process approach used in the Energy Intensive industry modelling. As an example, we analysed the impact of heat recovery with heat pumps (HP) on industrial processes up to 2020 on energy savings and CO2 emissions reductions in the French food and drink industry (F and D), the biggest NEI sector. The results showed HP could be an excellent and very promising energy recovery technology. For further detailed analysis, the depiction of HP investment cost payments is given per temperature range for each F and D subsector. This model constitutes a useful decision-making tool for assessing potential energy savings from investing in efficient technologies at the highest level of disaggregation, as well as a better subsectoral screening

  13. A bottom-up model to estimate the energy efficiency improvement and CO2 emission reduction potentials in the Chinese iron and steel industry

    International Nuclear Information System (INIS)

    China's annual crude steel production in 2010 was 638.7 Mt accounting for nearly half of the world's annual crude steel production in the same year. Around 461 TWh of electricity and 14,872 PJ of fuel were consumed to produce this quantity of steel. We identified and analyzed 23 energy efficiency technologies and measures applicable to the processes in China's iron and steel industry. Using a bottom-up electricity CSC (Conservation Supply Curve) model, the cumulative cost-effective electricity savings potential for the Chinese iron and steel industry for 2010–2030 is estimated to be 251 TWh, and the total technical electricity saving potential is 416 TWh. The CO2 emissions reduction associated with cost-effective electricity savings is 139 Mt CO2 and the CO2 emission reduction associated with technical electricity saving potential is 237 Mt CO2. The FCSC (Fuel CSC) model for the Chinese iron and steel industry shows cumulative cost-effective fuel savings potential of 11,999 PJ, and the total technical fuel saving potential is 12,139. The CO2 emissions reduction associated with cost-effective and technical fuel savings is 1191 Mt CO2 and 1205 Mt CO2, respectively. In addition, a sensitivity analysis with respect to the discount rate used is conducted. - Highlights: ► Estimation of energy saving potential in the entire Chinese steel industry. ► Development of the bottom-up technology-rich Conservation Supply Curve models. ► Discussion of different approaches for developing Conservation Supply Curves. ► Primary energy saving over 20 years equal to 72% of primary energy of Latin America

  14. Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

    Science.gov (United States)

    Acton, W. J. F.; Schallhart, S.; Langford, B.; Valach, A.; Rantala, P.; Fares, S.; Carriero, G.; Tillmann, R.; Tomlinson, S. J.; Dragosits, U.; Gianelle, D.; Hewitt, C. N.; Nemitz, E.

    2015-10-01

    This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton transfer reaction-mass spectrometer (PTR-MS) and a proton transfer reaction-time of flight-mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (PTR-MS) and eddy covariance (PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean day-time flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28 day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the MEGAN isoprene emissions algorithms (Guenther et al., 2006). A detailed tree species distribution map for the site enabled the leaf-level emissions of isoprene and monoterpenes recorded using GC-MS to be scaled up to produce a "bottom-up" canopy-scale flux. This was compared with the "top-down" canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

  15. Visual scanning and recognition of Chinese, Caucasian, and racially ambiguous faces: contributions from bottom-up facial physiognomic information and top-down knowledge of racial categories.

    Science.gov (United States)

    Wang, Qiandong; Xiao, Naiqi G; Quinn, Paul C; Hu, Chao S; Qian, Miao; Fu, Genyue; Lee, Kang

    2015-02-01

    Recent studies have shown that participants use different eye movement strategies when scanning own- and other-race faces. However, it is unclear (1) whether this effect is related to face recognition performance, and (2) to what extent this effect is influenced by top-down or bottom-up facial information. In the present study, Chinese participants performed a face recognition task with Chinese, Caucasian, and racially ambiguous faces. For the racially ambiguous faces, we led participants to believe that they were viewing either own-race Chinese faces or other-race Caucasian faces. Results showed that (1) Chinese participants scanned the nose of the true Chinese faces more than that of the true Caucasian faces, whereas they scanned the eyes of the Caucasian faces more than those of the Chinese faces; (2) they scanned the eyes, nose, and mouth equally for the ambiguous faces in the Chinese condition compared with those in the Caucasian condition; (3) when recognizing the true Chinese target faces, but not the true target Caucasian faces, the greater the fixation proportion on the nose, the faster the participants correctly recognized these faces. The same was true when racially ambiguous face stimuli were thought to be Chinese faces. These results provide the first evidence to show that (1) visual scanning patterns of faces are related to own-race face recognition response time, and (2) it is bottom-up facial physiognomic information that mainly contributes to face scanning. However, top-down knowledge of racial categories can influence the relationship between face scanning patterns and recognition response time. PMID:25497461

  16. Top-down and bottom-up identification of proteins by liquid extraction surface analysis mass spectrometry of healthy and diseased human liver tissue.

    Science.gov (United States)

    Sarsby, Joscelyn; Martin, Nicholas J; Lalor, Patricia F; Bunch, Josephine; Cooper, Helen J

    2014-11-01

    Liquid extraction surface analysis mass spectrometry (LESA MS) has the potential to become a useful tool in the spatially-resolved profiling of proteins in substrates. Here, the approach has been applied to the analysis of thin tissue sections from human liver. The aim was to determine whether LESA MS was a suitable approach for the detection of protein biomarkers of nonalcoholic liver disease (nonalcoholic steatohepatitis, NASH), with a view to the eventual development of LESA MS for imaging NASH pathology. Two approaches were considered. In the first, endogenous proteins were extracted from liver tissue sections by LESA, subjected to automated trypsin digestion, and the resulting peptide mixture was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) (bottom-up approach). In the second (top-down approach), endogenous proteins were extracted by LESA, and analyzed intact. Selected protein ions were subjected to collision-induced dissociation (CID) and/or electron transfer dissociation (ETD) mass spectrometry. The bottom-up approach resulted in the identification of over 500 proteins; however identification of key protein biomarkers, liver fatty acid binding protein (FABP1), and its variant (Thr→Ala, position 94), was unreliable and irreproducible. Top-down LESA MS analysis of healthy and diseased liver tissue revealed peaks corresponding to multiple (~15-25) proteins. MS/MS of four of these proteins identified them as FABP1, its variant, α-hemoglobin, and 10 kDa heat shock protein. The reliable identification of FABP1 and its variant by top-down LESA MS suggests that the approach may be suitable for imaging NASH pathology in sections from liver biopsies. PMID:25183224

  17. Identifying the computational requirements of an integrated top-down-bottom-up model for overt visual attention within an active vision system.

    Directory of Open Access Journals (Sweden)

    Sebastian McBride

    Full Text Available Computational visual attention systems have been constructed in order for robots and other devices to detect and locate regions of interest in their visual world. Such systems often attempt to take account of what is known of the human visual system and employ concepts, such as 'active vision', to gain various perceived advantages. However, despite the potential for gaining insights from such experiments, the computational requirements for visual attention processing are often not clearly presented from a biological perspective. This was the primary objective of this study, attained through two specific phases of investigation: 1 conceptual modeling of a top-down-bottom-up framework through critical analysis of the psychophysical and neurophysiological literature, 2 implementation and validation of the model into robotic hardware (as a representative of an active vision system. Seven computational requirements were identified: 1 transformation of retinotopic to egocentric mappings, 2 spatial memory for the purposes of medium-term inhibition of return, 3 synchronization of 'where' and 'what' information from the two visual streams, 4 convergence of top-down and bottom-up information to a centralized point of information processing, 5 a threshold function to elicit saccade action, 6 a function to represent task relevance as a ratio of excitation and inhibition, and 7 derivation of excitation and inhibition values from object-associated feature classes. The model provides further insight into the nature of data representation and transfer between brain regions associated with the vertebrate 'active' visual attention system. In particular, the model lends strong support to the functional role of the lateral intraparietal region of the brain as a primary area of information consolidation that directs putative action through the use of a 'priority map'.

  18. Assuring Quality "Bottom-up"

    Czech Academy of Sciences Publication Activity Database

    Hašková, Hana

    Berlin: AGF, 2015. s. 20-21. [Good Quality In Early Childcare - Ideas, Goals And Strategies In Europe. 20150625, Berlin] R&D Projects: GA ČR GA15-13766S Institutional support: RVO:68378025 Subject RIV: AO - Sociology, Demography

  19. Bottom-up disaster resilience

    Science.gov (United States)

    Chan, Emily Y. Y.

    2013-05-01

    The 2008 Wenchuan earthquake highlights some of the successes of government-led schemes to mitigate the impact of natural disasters. A stronger focus on individuals and local communities could reduce losses even further in the future.

  20. Heart Disease Risk Factors You Can Control

    Science.gov (United States)

    ... disease: Know your risk Heart Health and Stroke Heart disease risk factors you can control Did you know? ... overall health. Return to top More information on Heart disease risk factors you can control Read more from ...

  1. Top-down model estimates, bottom-up inventories, and future projections of global natural and anthropogenic emissions of nitrous oxide

    Science.gov (United States)

    Davidson, E. A.; Kanter, D.

    2013-12-01

    Nitrous oxide (N2O) is the third most abundantly emitted greenhouse gas and the largest remaining emitted ozone depleting substance. It is a product of nitrifying and denitrifying bacteria in soils, sediments and water bodies. Humans began to disrupt the N cycle in the preindustrial era as they expanded agricultural land, used fire for land clearing and management, and cultivated leguminous crops that carry out biological N fixation. This disruption accelerated after the industrial revolution, especially as the use of synthetic N fertilizers became common after 1950. Here we present findings from a new United Nations Environment Programme report, in which we constrain estimates of the anthropogenic and natural emissions of N2O and consider scenarios for future emissions. Inventory-based estimates of natural emissions from terrestrial, marine and atmospheric sources range from 10 to 12 Tg N2O-N/yr. Similar values can be derived for global N2O emissions that were predominantly natural before the industrial revolution. While there was inter-decadal variability, there was little or no consistent trend in atmospheric N2O concentrations between 1730 and 1850, allowing us to assume near steady state. Assuming an atmospheric lifetime of 120 years, the 'top-down' estimate of pre-industrial emissions of 11 Tg N2O-N/yr is consistent with the bottom-up inventories for natural emissions, although the former includes some modest pre-industrial anthropogenic effects (probably top-down methodology yields an estimate of 5.3 Tg N2O-N/yr (range 5.2 - 5.5) net anthropogenic emissions for the period 2000-2007. Based on a review of bottom-up inventories, we estimate total net anthropogenic N2O emissions of 6.0 Tg N2O-N/yr (5.4-8.4 Tg N2O-N/yr). Estimates (and ranges) by sector (in Tg N2O-N/yr) are: agriculture 4.1 Tg (3.8-6.8); biomass burning 0.7 (0.5-1.7); energy and transport 0.7 (0.5-1.2); industry 0.7 (0.3-1.1); and other 0.5 (0.2 - 0.8). Tropical deforestation has reduced

  2. Canopy-scale flux measurements and bottom-up emission estimates of volatile organic compounds from a mixed oak and hornbeam forest in northern Italy

    Science.gov (United States)

    Acton, W. Joe F.; Schallhart, Simon; Langford, Ben; Valach, Amy; Rantala, Pekka; Fares, Silvano; Carriero, Giulia; Tillmann, Ralf; Tomlinson, Sam J.; Dragosits, Ulrike; Gianelle, Damiano; Hewitt, C. Nicholas; Nemitz, Eiko

    2016-06-01

    This paper reports the fluxes and mixing ratios of biogenically emitted volatile organic compounds (BVOCs) 4 m above a mixed oak and hornbeam forest in northern Italy. Fluxes of methanol, acetaldehyde, isoprene, methyl vinyl ketone + methacrolein, methyl ethyl ketone and monoterpenes were obtained using both a proton-transfer-reaction mass spectrometer (PTR-MS) and a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) together with the methods of virtual disjunct eddy covariance (using PTR-MS) and eddy covariance (using PTR-ToF-MS). Isoprene was the dominant emitted compound with a mean daytime flux of 1.9 mg m-2 h-1. Mixing ratios, recorded 4 m above the canopy, were dominated by methanol with a mean value of 6.2 ppbv over the 28-day measurement period. Comparison of isoprene fluxes calculated using the PTR-MS and PTR-ToF-MS showed very good agreement while comparison of the monoterpene fluxes suggested a slight over estimation of the flux by the PTR-MS. A basal isoprene emission rate for the forest of 1.7 mg m-2 h-1 was calculated using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) isoprene emission algorithms (Guenther et al., 2006). A detailed tree-species distribution map for the site enabled the leaf-level emission of isoprene and monoterpenes recorded using gas-chromatography mass spectrometry (GC-MS) to be scaled up to produce a bottom-up canopy-scale flux. This was compared with the top-down canopy-scale flux obtained by measurements. For monoterpenes, the two estimates were closely correlated and this correlation improved when the plant-species composition in the individual flux footprint was taken into account. However, the bottom-up approach significantly underestimated the isoprene flux, compared with the top-down measurements, suggesting that the leaf-level measurements were not representative of actual emission rates.

  3. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands.

    Science.gov (United States)

    Yam, Rita S W; Fan, Yen-Tzu; Wang, Tzu-Ting

    2016-03-01

    Pomacea canaliculata (Ampullariidae) has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents. PMID:26927135

  4. Importance of Macrophyte Quality in Determining Life-History Traits of the Apple Snails Pomacea canaliculata: Implications for Bottom-Up Management of an Invasive Herbivorous Pest in Constructed Wetlands

    Directory of Open Access Journals (Sweden)

    Rita S. W. Yam

    2016-02-01

    Full Text Available Pomacea canaliculata (Ampullariidae has extensively invaded most Asian constructed wetlands and its massive herbivory of macrophytes has become a major cause of ecosystem dysfunctioning of these restored habitats. We conducted non-choice laboratory feeding experiments of P. canaliculata using five common macrophyte species in constructed wetlands including Ipomoea aquatica, Commelina communis, Nymphoides coreana, Acorus calamus and Phragmites australis. Effects of macrophytes on snail feeding, growth and fecundity responses were evaluated. Results indicated that P. canaliculata reared on Ipomoea had the highest feeding and growth rates with highest reproductive output, but all individuals fed with Phragmites showed lowest feeding rates and little growth with poorest reproductive output. Plant N and P contents were important for enhancing palatability, supporting growth and offspring quantity of P. canaliculata, whilst toughness, cellulose and phenolics had critically deterrent effects on various life-history traits. Although snail offspring quality was generally consistent regardless of maternal feeding conditions, the reduced growth and offspring quantity of the poorly-fed snails in constructed wetlands dominated by the less-palatable macrophytes could limit the invasive success of P. canaliculata. Effective bottom-up control of P. canaliculata in constructed wetlands should involve selective planting strategy using macrophytes with low nutrient and high toughness, cellulose and phenolic contents.

  5. Three-Phase Power Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1982-01-01

    Three-Phase Power-Factor Controller develops a control signal for each motor winding. As motor loading decreases, rms value of applied voltage is decreased by feedback-control circuit. Power consumption is therefore lower than in unregulated operation. Controller employs phase detector for each of three phases of delta-connected induction motor. Phase-difference sum is basis for control.

  6. Bottom-up coarse-grained models with predictive accuracy and transferability for both structural and thermodynamic properties of heptane-toluene mixtures

    Science.gov (United States)

    Dunn, Nicholas J. H.; Noid, W. G.

    2016-05-01

    This work investigates the promise of a "bottom-up" extended ensemble framework for developing coarse-grained (CG) models that provide predictive accuracy and transferability for describing both structural and thermodynamic properties. We employ a force-matching variational principle to determine system-independent, i.e., transferable, interaction potentials that optimally model the interactions in five distinct heptane-toluene mixtures. Similarly, we employ a self-consistent pressure-matching approach to determine a system-specific pressure correction for each mixture. The resulting CG potentials accurately reproduce the site-site rdfs, the volume fluctuations, and the pressure equations of state that are determined by all-atom (AA) models for the five mixtures. Furthermore, we demonstrate that these CG potentials provide similar accuracy for additional heptane-toluene mixtures that were not included their parameterization. Surprisingly, the extended ensemble approach improves not only the transferability but also the accuracy of the calculated potentials. Additionally, we observe that the required pressure corrections strongly correlate with the intermolecular cohesion of the system-specific CG potentials. Moreover, this cohesion correlates with the relative "structure" within the corresponding mapped AA ensemble. Finally, the appendix demonstrates that the self-consistent pressure-matching approach corresponds to minimizing an appropriate relative entropy.

  7. Benchmarking Non-Hardware Balance-of-System (Soft) Costs for U.S. Photovoltaic Systems, Using a Bottom-Up Approach and Installer Survey - Second Edition

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, B.; Ardani, K.; Feldman, D.; Citron, R.; Margolis, R.; Zuboy, J.

    2013-10-01

    This report presents results from the second U.S. Department of Energy (DOE) sponsored, bottom-up data-collection and analysis of non-hardware balance-of-system costs -- often referred to as 'business process' or 'soft' costs -- for U.S. residential and commercial photovoltaic (PV) systems. In service to DOE's SunShot Initiative, annual expenditure and labor-hour-productivity data are analyzed to benchmark 2012 soft costs related to (1) customer acquisition and system design (2) permitting, inspection, and interconnection (PII). We also include an in-depth analysis of costs related to financing, overhead, and profit. Soft costs are both a major challenge and a major opportunity for reducing PV system prices and stimulating SunShot-level PV deployment in the United States. The data and analysis in this series of benchmarking reports are a step toward the more detailed understanding of PV soft costs required to track and accelerate these price reductions.

  8. Synthesis of a Cementitious Material Nanocement Using Bottom-Up Nanotechnology Concept: An Alternative Approach to Avoid CO2 Emission during Production of Cement

    Directory of Open Access Journals (Sweden)

    Byung Wan Jo

    2014-01-01

    Full Text Available The world’s increasing need is to develop smart and sustainable construction material, which will generate minimal climate changing gas during their production. The bottom-up nanotechnology has established itself as a promising alternative technique for the production of the cementitious material. The present investigation deals with the chemical synthesis of cementitious material using nanosilica, sodium aluminate, sodium hydroxide, and calcium nitrate as reacting phases. The characteristic properties of the chemically synthesized nanocement were verified by the chemical composition analysis, setting time measurement, particle size distribution, fineness analysis, and SEM and XRD analyses. Finally, the performance of the nanocement was ensured by the fabrication and characterization of the nanocement based mortar. Comparing the results with the commercially available cement product, it is demonstrated that the chemically synthesized nanocement not only shows better physical and mechanical performance, but also brings several encouraging impacts to the society, including the reduction of CO2 emission and the development of sustainable construction material. A plausible reaction scheme has been proposed to explain the synthesis and the overall performances of the nanocement.

  9. Bottom-up derivation of conservative and dissipative interactions for coarse-grained molecular liquids with the conditional reversible work method

    Energy Technology Data Exchange (ETDEWEB)

    Deichmann, Gregor; Marcon, Valentina; Vegt, Nico F. A. van der, E-mail: vandervegt@csi.tu-darmstadt.de [Center of Smart Interfaces, Technische Universität Darmstadt, Alarich-Weiss-Straße 10, 64287 Darmstadt (Germany)

    2014-12-14

    Molecular simulations of soft matter systems have been performed in recent years using a variety of systematically coarse-grained models. With these models, structural or thermodynamic properties can be quite accurately represented while the prediction of dynamic properties remains difficult, especially for multi-component systems. In this work, we use constraint molecular dynamics simulations for calculating dissipative pair forces which are used together with conditional reversible work (CRW) conservative forces in dissipative particle dynamics (DPD) simulations. The combined CRW-DPD approach aims to extend the representability of CRW models to dynamic properties and uses a bottom-up approach. Dissipative pair forces are derived from fluctuations of the direct atomistic forces between mapped groups. The conservative CRW potential is obtained from a similar series of constraint dynamics simulations and represents the reversible work performed to couple the direct atomistic interactions between the mapped atom groups. Neopentane, tetrachloromethane, cyclohexane, and n-hexane have been considered as model systems. These molecular liquids are simulated with atomistic molecular dynamics, coarse-grained molecular dynamics, and DPD. We find that the CRW-DPD models reproduce the liquid structure and diffusive dynamics of the liquid systems in reasonable agreement with the atomistic models when using single-site mapping schemes with beads containing five or six heavy atoms. For a two-site representation of n-hexane (3 carbons per bead), time scale separation can no longer be assumed and the DPD approach consequently fails to reproduce the atomistic dynamics.

  10. Middle-Out Approaches to Reform of University Teaching and Learning: Champions striding between the top-down and bottom-up approaches

    Directory of Open Access Journals (Sweden)

    Rick Cummings

    2005-03-01

    Full Text Available In recent years, Australian universities have been driven by a diversity of external forces, including funding cuts, massification of higher education, and changing student demographics, to reform their relationship with students and improve teaching and learning, particularly for those studying off-campus or part-time. Many universities have responded to these forces either through formal strategic plans developed top-down by executive staff or through organic developments arising from staff in a bottom-up approach. By contrast, much of Murdoch University’s response has been led by a small number of staff who have middle management responsibilities and who have championed the reform of key university functions, largely in spite of current policy or accepted practice. This paper argues that the ‘middle-out’ strategy has both a basis in change management theory and practice, and a number of strengths, including low risk, low cost, and high sustainability. Three linked examples of middle-out change management in teaching and learning at Murdoch University are described and the outcomes analyzed to demonstrate the benefits and pitfalls of this approach.

  11. Bottom-up derivation of conservative and dissipative interactions for coarse-grained molecular liquids with the conditional reversible work method

    International Nuclear Information System (INIS)

    Molecular simulations of soft matter systems have been performed in recent years using a variety of systematically coarse-grained models. With these models, structural or thermodynamic properties can be quite accurately represented while the prediction of dynamic properties remains difficult, especially for multi-component systems. In this work, we use constraint molecular dynamics simulations for calculating dissipative pair forces which are used together with conditional reversible work (CRW) conservative forces in dissipative particle dynamics (DPD) simulations. The combined CRW-DPD approach aims to extend the representability of CRW models to dynamic properties and uses a bottom-up approach. Dissipative pair forces are derived from fluctuations of the direct atomistic forces between mapped groups. The conservative CRW potential is obtained from a similar series of constraint dynamics simulations and represents the reversible work performed to couple the direct atomistic interactions between the mapped atom groups. Neopentane, tetrachloromethane, cyclohexane, and n-hexane have been considered as model systems. These molecular liquids are simulated with atomistic molecular dynamics, coarse-grained molecular dynamics, and DPD. We find that the CRW-DPD models reproduce the liquid structure and diffusive dynamics of the liquid systems in reasonable agreement with the atomistic models when using single-site mapping schemes with beads containing five or six heavy atoms. For a two-site representation of n-hexane (3 carbons per bead), time scale separation can no longer be assumed and the DPD approach consequently fails to reproduce the atomistic dynamics

  12. Evolutionary Steps in the Emergence of Life Deduced from the Bottom-Up Approach and GADV Hypothesis (Top-Down Approach

    Directory of Open Access Journals (Sweden)

    Kenji Ikehara

    2016-01-01

    Full Text Available It is no doubt quite difficult to solve the riddle of the origin of life. So, firstly, I would like to point out the kinds of obstacles there are in solving this riddle and how we should tackle these difficult problems, reviewing the studies that have been conducted so far. After that, I will propose that the consecutive evolutionary steps in a timeline can be rationally deduced by using a common event as a juncture, which is obtained by two counter-directional approaches: one is the bottom-up approach through which many researchers have studied the origin of life, and the other is the top-down approach, through which I established the [GADV]-protein world hypothesis or GADV hypothesis on the origin of life starting from a study on the formation of entirely new genes in extant microorganisms. Last, I will describe the probable evolutionary process from the formation of Earth to the emergence of life, which was deduced by using a common event—the establishment of the first genetic code encoding [GADV]-amino acids—as a juncture for the results obtained from the two approaches.

  13. Employment impacts of EU biofuels policy. Combining bottom-up technology information and sectoral market simulations in an input-output framework

    International Nuclear Information System (INIS)

    This paper analyses the employment consequences of policies aimed to support biofuels in the European Union. The promotion of biofuel use has been advocated as a means to promote the sustainable use of natural resources and to reduce greenhouse gas emissions originating from transport activities on the one hand, and to reduce dependence on imported oil and thereby increase security of the European energy supply on the other hand. The employment impacts of increasing biofuels shares are calculated by taking into account a set of elements comprising the demand for capital goods required to produce biofuels, the additional demand for agricultural feedstock, higher fuel prices or reduced household budget in the case of price subsidisation, price effects ensuing from a hypothetical world oil price reduction linked to substitution in the EU market, and price impacts on agro-food commodities. The calculations refer to scenarios for the year 2020 targets as set out by the recent Renewable Energy Roadmap. Employment effects are assessed in an input-output framework taking into account bottom-up technology information to specify biofuels activities and linked to partial equilibrium models for the agricultural and energy sectors. The simulations suggest that biofuels targets on the order of 10-15% could be achieved without adverse net employment effects. (author)

  14. Structural and optical nanoscale analysis of GaN core-shell microrod arrays fabricated by combined top-down and bottom-up process on Si(111)

    Science.gov (United States)

    Müller, Marcus; Schmidt, Gordon; Metzner, Sebastian; Veit, Peter; Bertram, Frank; Krylyuk, Sergiy; Debnath, Ratan; Ha, Jong-Yoon; Wen, Baomei; Blanchard, Paul; Motayed, Abhishek; King, Matthew R.; Davydov, Albert V.; Christen, Jürgen

    2016-05-01

    Large arrays of GaN core-shell microrods were fabricated on Si(111) substrates applying a combined bottom-up and top-down approach which includes inductively coupled plasma (ICP) etching of patterned GaN films grown by metal-organic vapor phase epitaxy (MOVPE) and selective overgrowth of obtained GaN/Si pillars using hydride vapor phase epitaxy (HVPE). The structural and optical properties of individual core-shell microrods have been studied with a nanometer scale spatial resolution using low-temperature cathodoluminescence spectroscopy (CL) directly performed in a scanning electron microscope (SEM) and in a scanning transmission electron microscope (STEM). SEM, TEM, and CL measurements reveal the formation of distinct growth domains during the HVPE overgrowth. A high free-carrier concentration observed in the non-polar \\{ 1\\bar{1}00\\} HVPE shells is assigned to in-diffusion of silicon atoms from the substrate. In contrast, the HVPE shells directly grown on top of the c-plane of the GaN pillars reveal a lower free-carrier concentration.

  15. Top-down/bottom-up description of electricity sector for Switzerland using the GEM-E3 computable general equilibrium model

    International Nuclear Information System (INIS)

    Participation of the Paul Scherrer Institute (PSI) in the advancement and extension of the multi-region, Computable General Equilibrium (CGE) model GEM-E3 (CES/KUL, 2002) focused primarily on two top-level facets: a) extension of the model database and model calibration, particularly as related to the second component of this study, which is; b) advancement of the dynamics of innovation and investment, primarily through the incorporation of Exogenous Technical Learning (ETL) into he Bottom-Up (BU, technology-based) part of the dynamic upgrade; this latter activity also included the completion of the dynamic coupling of the BU description of the electricity sector with the 'Top-Down' (TD, econometric) description of the economy inherent to the GEM-E3 CGE model. The results of this two- component study are described in two parts that have been combined in this single summary report: Part I describes the methodology and gives illustrative results from the BUTD integration, as well as describing the approach to and giving preliminary results from incorporating an ETL description into the BU component of the overall model; Part II reports on the calibration component of task in terms of: a) formulating a BU technology database for Switzerland based on previous work; incorporation of that database into the GEM-E3 model; and calibrating the BU database with the TD database embodied in the (Swiss) Social Accounting Matrix (SAM). The BUTD coupling along with the ETL incorporation described in Part I represent the major effort embodied in this investigation, but this effort could not be completed without the calibration preamble reported herein as Part II. A brief summary of the scope of each of these key study components is given. (author)

  16. A comparison of top-down and bottom-up carbon dioxide fluxes in the UK using a multi-platform measurement network.

    Science.gov (United States)

    White, Emily; Rigby, Matt; O'Doherty, Simon; Stavert, Ann; Lunt, Mark; Nemitz, Eiko; Helfter, Carole; Allen, Grant; Pitt, Joe; Bauguitte, Stéphane; Levy, Pete; van Oijen, Marcel; Williams, Mat; Smallman, Luke; Palmer, Paul

    2016-04-01

    Having a comprehensive understanding, on a countrywide scale, of both biogenic and anthropogenic CO2 emissions is essential for knowing how best to reduce anthropogenic emissions and for understanding how the terrestrial biosphere is responding to global fossil fuel emissions. Whilst anthropogenic CO2 flux estimates are fairly well constrained, fluxes from biogenic sources are not. This work will help to verify existing anthropogenic emissions inventories and give a better understanding of biosphere - atmosphere CO2 exchange. Using an innovative top-down inversion scheme; a hierarchical Bayesian Markov Chain Monte Carlo approach with reversible jump "trans-dimensional" basis function selection, we aim to find emissions estimates for biogenic and anthropogenic sources simultaneously. Our approach allows flux uncertainties to be derived more comprehensively than previous methods, and allows the resolved spatial scales in the solution to be determined using the data. We use atmospheric CO2 mole fraction data from the UK Deriving Emissions related to Climate Change (DECC) and Greenhouse gAs UK and Global Emissions (GAUGE) projects. The network comprises of 6 tall tower sites, flight campaigns and a ferry transect along the east coast, and enables us to derive high-resolution monthly flux estimates across the UK and Ireland for the period 2013-2015. We have derived UK total fluxes of 675 PIC 78 Tg/yr during January 2014 (seasonal maximum) and 23 PIC 96 Tg/yr during May 2014 (seasonal minimum). Our disaggregated anthropogenic and biogenic flux estimates are compared to a new high-resolution time resolved anthropogenic inventory that will underpin future UNFCCC reports by the UK, and to DALEC carbon cycle model. This allows us to identify where significant differences exist between these "bottom-up" and "top-down" flux estimates and suggest reasons for discrepancies. We will highlight the strengths and limitations of the UK's CO2 emissions verification infrastructure at

  17. Top-down/bottom-up description of electricity sector for Switzerland using the GEM-E3 computable general equilibrium model

    Energy Technology Data Exchange (ETDEWEB)

    Krakowski, R. A

    2006-06-15

    Participation of the Paul Scherrer Institute (PSI) in the advancement and extension of the multi-region, Computable General Equilibrium (CGE) model GEM-E3 (CES/KUL, 2002) focused primarily on two top-level facets: a) extension of the model database and model calibration, particularly as related to the second component of this study, which is; b) advancement of the dynamics of innovation and investment, primarily through the incorporation of Exogenous Technical Learning (ETL) into he Bottom-Up (BU, technology-based) part of the dynamic upgrade; this latter activity also included the completion of the dynamic coupling of the BU description of the electricity sector with the 'Top-Down' (TD, econometric) description of the economy inherent to the GEM-E3 CGE model. The results of this two- component study are described in two parts that have been combined in this single summary report: Part I describes the methodology and gives illustrative results from the BUTD integration, as well as describing the approach to and giving preliminary results from incorporating an ETL description into the BU component of the overall model; Part II reports on the calibration component of task in terms of: a) formulating a BU technology database for Switzerland based on previous work; incorporation of that database into the GEM-E3 model; and calibrating the BU database with the TD database embodied in the (Swiss) Social Accounting Matrix (SAM). The BUTD coupling along with the ETL incorporation described in Part I represent the major effort embodied in this investigation, but this effort could not be completed without the calibration preamble reported herein as Part II. A brief summary of the scope of each of these key study components is given. (author)

  18. Reducing energy consumption and CO2 emissions by energy efficiency measures and international trading: A bottom-up modeling for the U.S. iron and steel sector

    International Nuclear Information System (INIS)

    Highlights: • Use ISEEM to evaluate energy and emission reduction in U.S. Iron and Steel sector. • ISEEM is a new bottom-up optimization model for industry sector energy planning. • Energy and emission reduction includes efficiency measure and international trading. • International trading includes commodity and carbon among U.S., China and India. • Project annual energy use, CO2 emissions, production, and costs from 2010 to 2050. - Abstract: Using the ISEEM modeling framework, we analyzed the roles of energy efficiency measures, steel commodity and international carbon trading in achieving specific CO2 emission reduction targets in the U.S iron and steel sector from 2010 to 2050. We modeled how steel demand is balanced under three alternative emission reduction scenarios designed to include national energy efficiency measures, commodity trading, and international carbon trading as key instruments to meet a particular emission restriction target in the U.S. iron and steel sector; and how production, process structure, energy supply, and system costs change with those scenarios. The results advance our understanding of long-term impacts of different energy policy options designed to reduce energy consumption and CO2 emissions for U.S. iron and steel sector, and generate insight of policy implications for the sector’s environmentally and economically sustainable development. The alternative scenarios associated with 20% emission-reduction target are projected to result in approximately 11–19% annual energy reduction in the medium term (i.e., 2030) and 9–20% annual energy reduction in the long term (i.e., 2050) compared to the Base scenario

  19. Causal Factors in Genome Control

    NARCIS (Netherlands)

    O'Duibhir, E.

    2015-01-01

    The aim of this thesis is to study how genes are switched on and off in a coordinated way across an entire genome. In order to do this yeast is used as a model organism. The mechanisms that control gene expression in yeast are very similar to those of human cells. Chapter 1 provides a general introd

  20. Energetic Bottomup in the Low Countries. Energy transition from the bottom-up. On Happy energetic civilians, Solar and wind cooperatives, New utility companies; Energieke BottomUp in Lage Landen. De Energietransitie van Onderaf. Over Vrolijke energieke burgers, Zon- en windcooperaties, Nieuwe nuts

    Energy Technology Data Exchange (ETDEWEB)

    Schwencke, A.M.

    2012-08-15

    This essay is an outline of the 'energy transition from the bottom-up'. Leading questions are: (1) what are the actual initiatives; (2) who is involved; (3) how does one work (organization, business models); (4) why are people active in this field; (5) what good is it; (6) what is the aim? The essay is based on public information sources (websites, blogs, publications) and interviews with people involved [Dutch] Dit essay is een verkenning van de 'energietransitie van onderaf'. Leidende vragen zijn: (1) om wat voor initiatieven gaat het nu eigenlijk?; (2) wie zijn daarbij betrokken?; (3) hoe gaat men te werk (organisatie, business modellen)?; (4) waarom is men er op die manier mee bezig?; (5) Zet het zoden aan de dijk?; (6) Waar beweegt het naar toe? Het essay baseert zich op openbare bronnen (websites, blogs, publicaties) en gesprekken met mensen uit het veld.

  1. Greenhouse Gas Emission Accounting. Preliminary study as input to a joint Int. IPCC Expert Meeting / CKO-CCB Workshop on Comparison of Top-down versus Bottom-up Emission Estimates.

    NARCIS (Netherlands)

    Amstel, van A.; Kroeze, C.; Janssen, L.J.H.M.; Olivier, J.G.J.; Wal, van der J.T.

    1997-01-01

    Bottom-up data for carbon dioxide, methane and nitrous oxide from the official national inventories (National Communications) were compared with data from EDGAR (Emission Database for Global Atmospheric Research) and top-down emission estimates, based on the results of dispersion and climate models

  2. Greenhouse Gas Emission Accounting: preliminary study as input to a joint International IPCC Expert Meeting/CKO-CCB Workshop on Comparison of Top-down versus Bottom-up Emission Estimates

    NARCIS (Netherlands)

    Amstel AR van; Kroeze C; Janssen LHJM; Olivier JGJ; Wal JT van der; LLO; LUW/WIMEK

    1997-01-01

    Bottom-up data for carbon dioxide, methane and nitrous oxide from the official national inventories (National Communications) were compared with data from EDGAR (Emission Database for Global Atmospheric Research) and top-down emission estimates, based on the results of dispersion and climate models

  3. Selective modification of nanoparticle arrays by laser-induced self assembly (MONA-LISA): putting control into bottom-up plasmonic nanostructuring

    Science.gov (United States)

    Kalfagiannis, Nikolaos; Siozios, Anastasios; Bellas, Dimitris V.; Toliopoulos, Dimosthenis; Bowen, Leon; Pliatsikas, Nikolaos; Cranton, Wayne M.; Kosmidis, Constantinos; Koutsogeorgis, Demosthenes C.; Lidorikis, Elefterios; Patsalas, Panos

    2016-04-01

    Nano-structuring of metals is one of the greatest challenges for the future of plasmonic and photonic devices. Such a technological challenge calls for the development of ultra-fast, high-throughput and low-cost fabrication techniques. Laser processing, accounts for the aforementioned properties, representing an unrivalled tool towards the anticipated arrival of modules based in metallic nanostructures, with an extra advantage: the ease of scalability. In the present work we take advantage of the ability to tune the laser wavelength to either match the absorption spectral profile of the metal or to be resonant with the plasma oscillation frequency, and demonstrate the utilization of different optical absorption mechanisms that are size-selective and enable the fabrication of pre-determined patterns of metal nanostructures. Thus, we overcome the greatest challenge of Laser Induced Self Assembly by combining simultaneously large-scale character with atomic-scale precision. The proposed process can serve as a platform that will stimulate further progress towards the engineering of plasmonic devices.Nano-structuring of metals is one of the greatest challenges for the future of plasmonic and photonic devices. Such a technological challenge calls for the development of ultra-fast, high-throughput and low-cost fabrication techniques. Laser processing, accounts for the aforementioned properties, representing an unrivalled tool towards the anticipated arrival of modules based in metallic nanostructures, with an extra advantage: the ease of scalability. In the present work we take advantage of the ability to tune the laser wavelength to either match the absorption spectral profile of the metal or to be resonant with the plasma oscillation frequency, and demonstrate the utilization of different optical absorption mechanisms that are size-selective and enable the fabrication of pre-determined patterns of metal nanostructures. Thus, we overcome the greatest challenge of Laser Induced Self Assembly by combining simultaneously large-scale character with atomic-scale precision. The proposed process can serve as a platform that will stimulate further progress towards the engineering of plasmonic devices. Electronic supplementary information (ESI) available: Extensive experimental results that corroborate the results and conclusions presented in the manuscript, but due to their extent cannot fit in the manuscript. The manuscript refers to specific sections here, but in its entirety this document presents the complete results of our MONA-LISA work. See DOI: 10.1039/c5nr09192f

  4. A Statistical Method for Estimating Missing GHG Emissions in Bottom-Up Inventories: The Case of Fossil Fuel Combustion in Industry in the Bogota Region, Colombia

    Science.gov (United States)

    Jimenez-Pizarro, R.; Rojas, A. M.; Pulido-Guio, A. D.

    2012-12-01

    The development of environmentally, socially and financially suitable greenhouse gas (GHG) mitigation portfolios requires detailed disaggregation of emissions by activity sector, preferably at the regional level. Bottom-up (BU) emission inventories are intrinsically disaggregated, but although detailed, they are frequently incomplete. Missing and erroneous activity data are rather common in emission inventories of GHG, criteria and toxic pollutants, even in developed countries. The fraction of missing and erroneous data can be rather large in developing country inventories. In addition, the cost and time for obtaining or correcting this information can be prohibitive or can delay the inventory development. This is particularly true for regional BU inventories in the developing world. Moreover, a rather common practice is to disregard or to arbitrarily impute low default activity or emission values to missing data, which typically leads to significant underestimation of the total emissions. Our investigation focuses on GHG emissions by fossil fuel combustion in industry in the Bogota Region, composed by Bogota and its adjacent, semi-rural area of influence, the Province of Cundinamarca. We found that the BU inventories for this sub-category substantially underestimate emissions when compared to top-down (TD) estimations based on sub-sector specific national fuel consumption data and regional energy intensities. Although both BU inventories have a substantial number of missing and evidently erroneous entries, i.e. information on fuel consumption per combustion unit per company, the validated energy use and emission data display clear and smooth frequency distributions, which can be adequately fitted to bimodal log-normal distributions. This is not unexpected as industrial plant sizes are typically log-normally distributed. Moreover, our statistical tests suggest that industrial sub-sectors, as classified by the International Standard Industrial Classification (ISIC

  5. A bottom-up, vulnerability-based framework for identifying the adaptive capacity of water resources systems in a changing climate

    Science.gov (United States)

    Culley, Sam; Noble, Stephanie; Timbs, Michael; Yates, Adam; Giuliani, Matteo; Castelletti, Andrea; Maier, Holger; Westra, Seth

    2015-04-01

    Water resource system infrastructure and operating policies are commonly designed on the assumption that the statistics of future rainfall, temperature and other hydrometeorological variables are equal to those of the historical record. There is now substantial evidence demonstrating that this assumption is no longer valid, and that climate change will significantly impact water resources systems worldwide. Under different climatic inputs, the performance of these systems may degrade to a point where they become unable to meet the primary objectives for which they were built. In such a changing context, using existing infrastructure more efficiently - rather than planning additional infrastructure - becomes key to restore the system's performance at acceptable levels and minimize financial investments and associated risk. The traditional top-down approach for assessing climate change impacts relies on the use of a cascade of models from the global to the local scale. However, it is often difficult to utilize this top-down approach in a decision-making procedure, as there is disparity amongst various climate projections, arising from incomplete scientific understanding of the complicated processes and feedbacks within the climate system, and model limitations in reproducing those relationships. In contrast with this top-down approach, this study contributes a framework to identify the adaptive capacity of water resource systems under changing climatic conditions adopting a bottom-up, vulnerability-based approach. The performance of the current system management is first assessed for a comprehensive range of climatic conditions, which are independent of climate model forecasts. The adaptive capacity of the system is then estimated by re-evaluating the performance of a set of adaptive operating policies, which are optimized for each climatic condition under which the system is simulated. The proposed framework reverses the perspective by identifying water system

  6. Phase Detector for Power-Factor Controller

    Science.gov (United States)

    Nola, F. J.

    1984-01-01

    Positive feedback assures reliable switching. Three Phase Power Factor Controller includes three phase detectors, each produces rectangular waves of duration approximately equal to lag time between line voltage and motor current.

  7. Human factors challenges for advanced process control

    International Nuclear Information System (INIS)

    New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls

  8. Thyristor Controlled Reactor for Power Factor Improvement

    Directory of Open Access Journals (Sweden)

    Sheila Mahapatra

    2014-04-01

    Full Text Available Power factor improvement is the essence of any power sector for reliable operation. This paper provides Thyristor Controlled Reactor regulated by programmed microcontroller which aids in improving power factor and retaining it close to unity under various loading conditions. The implementation is done on 8051 microcontrollerwhich isprogrammed using Keil software. To determine time lag between current and voltage PSpice softwareis used and to display power factor according tothe variation in loadProteus software is used. Whenever a capacitive load is connected to the transmission linea shunt reactor is connected which injects lagging reactive VARs to the power system. As a result the power factor is improved. The results given in this paper provides suitable microcontroller based reactive power compensation and power factor improvement technique using a Thyristor Controlled Reactor module.

  9. Greenhouse Gas Emission Accounting. Preliminary study as input to a joint Int. IPCC Expert Meeting / CKO-CCB Workshop on Comparison of Top-down versus Bottom-up Emission Estimates.

    OpenAIRE

    Amstel, van, R.; Kroeze, C.; Janssen, L.J.H.M.; Olivier, J. G. J.; Wal, van der, M.F.

    1997-01-01

    Bottom-up data for carbon dioxide, methane and nitrous oxide from the official national inventories (National Communications) were compared with data from EDGAR (Emission Database for Global Atmospheric Research) and top-down emission estimates, based on the results of dispersion and climate models using measured concentrations of greenhouse gases in the atmosphere. The aims of this preliminary study were to investigate the possibilities of comparing different types of emission inventories, t...

  10. Trial-by-trial adjustments in control triggered by incidentally encoded semantic cues

    OpenAIRE

    Blais, C; Harris, MB; Sinanian, MH; Bunge, SA

    2015-01-01

    © 2015 The Experimental Psychology Society Cognitive control mechanisms provide the flexibility to rapidly adapt to contextual demands. These contexts can be defined by top-down goals—but also by bottom-up perceptual factors, such as the location at which a visual stimulus appears. There are now several experiments reporting contextual control effects. Such experiments establish that contexts defined by low-level perceptual cues such as the location of a visual stimulus can lead to context-sp...

  11. Socioeconomic Factors and Asthma Control in Children

    Science.gov (United States)

    Cope, Shannon F.; Ungar, Wendy J.; Glazier, Richard H.

    2016-01-01

    Summary Objectives The objective of this study was to evaluate the association between socioeconomic factors and asthma control in children, as defined by the Canadian Pediatric Asthma Consensus Guidelines. Patients and Methods Cross-sectional data from a completed study of 879 asthmatic children between the ages of 1 and 18 residing in the Greater Toronto Area were used. The database included data on demographics, health status, asthma control, and health-related quality of life. Stepwise forward modeling multiple regression was used to investigate the impact of socioeconomic status on asthma control, based on six control parameters from the 2003 Canadian Pediatric Asthma Consensus Guidelines. Results Only 11% of patients met the requirements for acceptable control, while 20% had intermediate control, and 69% had unacceptable asthma control. Children from families in lower income adequacy levels had poorer control. Conclusions Disparities in asthma control between children from families of different socio-economic strata persist, even with adjustment for utilization of primary care services and use of controller medications. PMID:18615669

  12. Top-Down Versus Bottom-Up Estimative of CO2 and CO Vehicular Emission Contribution from the Megacity of SãO Paulo, Brazil

    Science.gov (United States)

    Andrade, M.; Nogueira, T.; Martínez, P. J.; Fornaro, A.; Miranda, R. M.; Ynoue, R.

    2013-12-01

    data presented here compared tunnel measurements performed in 2004 and 2011. The official data estimate an emission of 15327 million tons per year of CO2eq (60% by LDV, 38% HDV and 2% motorcycles) and 128 million tons per year of CO. The top-down estimative based on tunnel measurements resulted in values approximately 5 times higher, being the difference more attributable to the estimative of the diesel emission factor. The uncertainties are related to the deterioration of the emission factor with time and the driving pattern. The diurnal variation of CO2 atmospheric concentration is characterized by the mobile source emission pattern. CETESB. Relatório Anual de Qualidade do Ar no Estado de São Paulo 2012. Companhia de Tecnologia de Saneamento Ambiental, São Paulo, Brazil, 2013a. CETESB. Plano de Controle de Poluição Veicular do Estado de São Paulo 2011 /2013. Companhia de Tecnologia de Saneamento Ambiental, São Paulo, Brazil, 2013b.

  13. The effects of recent control policies on trends in emissions of anthropogenic atmospheric pollutants and CO2 in China

    OpenAIRE

    C. P. Nielsen; J. Zhang; Zhao, Y.

    2012-01-01

    To examine the effects of China's national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissi...

  14. The effects of recent control policies on trends in emissions of anthropogenic atmospheric pollutants and CO2 in China

    OpenAIRE

    C. P. Nielsen; J. Zhang; Zhao, Y.

    2013-01-01

    To examine the effects of China's national policies of energy conservation and emission control during 2005–2010, inter-annual emission trends of gaseous pollutants, primary aerosols, and CO2 are estimated with a bottom-up framework. The control measures led to improved energy efficiency and/or increased penetration of emission control devices at power plants and other important industrial sources, yielding reduced emission factors for all evaluated species except NOx. The national emissions ...

  15. Including Complexity, Heterogeneity and Vegetation Response Characteristics into Carbon Balance Assessments at Continental Scale: Stepwise Development of a Simulation Framework with the Bottom-Up Core Model PIXGRO

    Science.gov (United States)

    Tenhunen, J.; Geyer, R.; Owen, K.; Falge, E.; Reichstein, M.

    2005-12-01

    The cultural landscapes of the European continent are characterized by highly fragmented land cover, distributed along the gradient from extremely sparse, dry Mediterranean shrublands to sub-arctic wetlands and forests. In addition, several mountain systems, in particular the Alps, modify vegetation and land surface exchange characteristics. In the recently begun CARBOEUROPE project, energy, water and CO2 exchanges of selected ecosystem types are monitored via eddy covariance methods. The model PIXGRO is being developed to help relate measurements at flux tower sites to measurements carried out at larger scale and to CO2 exchange estimates obtained with atmospheric inversion techniques. The main question addressed in this modelling effort is how to efficiently include a spectrum of vegetation characteristics into carbon balance assessments at large scale and in such a way that the influence of local response on regional fluxes may be visualized and analyzed. Furthermore, the modelling attempts to demonstrate both strengths and weaknesses in existing ecosystem process information required to understand carbon balances. The model PIXGRO attempts to define continental distribution and controls on net ecosystem CO2 exchange for ca. 12 ecosystem types, including coniferous forest, deciduous forest, grassland, cropland (assumed dominated by grain crops), northern boreal mixed forest, tundra, wetlands, alpine forest, evergreen forest, evergreen shrubland, and Mediterranean oak woodland. The model uses a single layer canopy with two leaf classes (sun and shade) and a three layered rooting zone to estimate GPP, ecosystem respiration and overall ecosystem gas exchange. Maximum LAI is determined during each year from the MODIS LAI-product. In the case of grassland, crops, tundra and wetlands, classical growth routines estimate dynamic changes in the vegetation canopy. Soil/canopy coupling in response to drought reflects a root system hormonal signalling and is calibrated with

  16. Development Of A Web Service And Android 'APP' For The Distribution Of Rainfall Data. A Bottom-Up Remote Sensing Data Mining And Redistribution Project In The Age Of The 'Web 2.0'

    Science.gov (United States)

    Mantas, Vasco M.; Pereira, A. J. S. C.; Liu, Zhong

    2013-12-01

    A project was devised to develop a set of freely available applications and web services that can (1) simplify access from Mobile Devices to TOVAS data and (2) support the development of new datasets through data repackaging and mash-up. The bottom-up approach enables the multiplication of new services, often of limited direct interest to the organizations that produces the original, global datasets, but significant to small, local users. Through this multiplication of services, the development cost is transferred to the intermediate or end users and the entire process is made more efficient, even allowing new players to use the data in innovative ways.

  17. Aliphatic polycarbonate-based polyurethane elastomers and nanocomposites. I. The influence of hard-segment content and macrodiol-constitution on bottom-up self-assembly

    Czech Academy of Sciences Publication Activity Database

    Špírková, Milena; Poreba, Rafal; Pavličevič, Jelena; Kobera, Libor; Baldrian, Josef; Pekárek, Michal

    2012-01-01

    Roč. 126, č. 3 (2012), s. 1016-1030. ISSN 0021-8995 R&D Projects: GA ČR GAP108/10/0195 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyurethane elastomer * polycarbonate diol * nanocomposite Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.395, year: 2012

  18. Europe from the bottom up: A statistical examination of the central and northern European lithosphere–asthenosphere boundary from comparing seismological and electromagnetic observations

    Czech Academy of Sciences Publication Activity Database

    Jones, A. G.; Plomerová, Jaroslava; Korja, T.; Sodoudi, F.; Spakman, W.

    2010-01-01

    Roč. 120, č. 1-2 (2010), s. 14-29. ISSN 0024-4937 R&D Projects: GA AV ČR IAA300120709 Institutional research plan: CEZ:AV0Z30120515 Keywords : lithosphere-asthenosphere boundary * Europe * seismology * magnetotellurics Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 3.121, year: 2010

  19. Safety factor profile control in a tokamak

    CERN Document Server

    Bribiesca Argomedo, Federico; Prieur, Christophe

    2014-01-01

    Control of the Safety Factor Profile in a Tokamak uses Lyapunov techniques to address a challenging problem for which even the simplest physically relevant models are represented by nonlinear, time-dependent, partial differential equations (PDEs). This is because of the  spatiotemporal dynamics of transport phenomena (magnetic flux, heat, densities, etc.) in the anisotropic plasma medium. Robustness considerations are ubiquitous in the analysis and control design since direct measurements on the magnetic flux are impossible (its estimation relies on virtual sensors) and large uncertainties remain in the coupling between the plasma particles and the radio-frequency waves (distributed inputs). The Brief begins with a presentation of the reference dynamical model and continues by developing a Lyapunov function for the discretized system (in a polytopic linear-parameter-varying formulation). The limitations of this finite-dimensional approach motivate new developments in the infinite-dimensional framework. The t...

  20. Top-down and bottom-up induced shifts in bacterial abundance, production and community composition in an experimentally divided humic lake

    Czech Academy of Sciences Publication Activity Database

    Grossart, H. P.; Jezbera, Jan; Horňák, Karel; Hutalle, K. M. L.; Buck, U.; Šimek, Karel

    2008-01-01

    Roč. 10, č. 3 (2008), s. 635-652. ISSN 1462-2912 R&D Projects: GA ČR(CZ) GA206/05/0007 Institutional research plan: CEZ:AV0Z60170517 Keywords : in situ hybridization * meso- eutrophic reservoir * dissolved organic carbon * fresh-water reservoir * bacterioplankton community * dystrophic lake Subject RIV: EE - Microbiology, Virology Impact factor: 4.707, year: 2008

  1. Dynamics of astaxanthin, tocopherol (Vitamin E) and thiamine (Vitamin B1) in the Baltic Sea ecosystem : Bottom-up effects in an aquatic food web

    OpenAIRE

    Häubner, Norbert

    2010-01-01

    The thesis combines laboratory experiments and field expeditions to study production, transfer and consumption of non-enzymatic antioxidants and thiamine in an aquatic food web. In particular, I (1) documented spatial and seasonal variation of tocopherols and carotenoids in the Baltic Sea pelagic food web, and (2) examined the effects of abiotic and biotic factors on tocopherol, carotenoid and thiamine concentrations in phytoplankton, zooplankton and fish. Moderate differences in temperature ...

  2. What drives farmers to make top-down or bottom-up adaptation to climate change and fluctuations? A comparative study on 3 cases of apple farming in Japan and South Africa.

    Directory of Open Access Journals (Sweden)

    Mariko Fujisawa

    Full Text Available Agriculture is one of the most vulnerable sectors to climate change. Farmers have been exposed to multiple stressors including climate change, and they have managed to adapt to those risks. The adaptation actions undertaken by farmers and their decision making are, however, only poorly understood. By studying adaptation practices undertaken by apple farmers in three regions: Nagano and Kazuno in Japan and Elgin in South Africa, we categorize the adaptation actions into two types: farmer initiated bottom-up adaptation and institution led top-down adaptation. We found that the driver which differentiates the type of adaptation likely adopted was strongly related to the farmers' characteristics, particularly their dependence on the institutions, e.g. the farmers' cooperative, in selling their products. The farmers who rely on the farmers' cooperative for their sales are likely to adopt the institution-led adaptation, whereas the farmers who have established their own sales channels tend to start innovative actions by bottom-up. We further argue that even though the two types have contrasting features, the combinations of the both types of adaptations could lead to more successful adaptation particularly in agriculture. This study also emphasizes that more farm-level studies for various crops and regions are warranted to provide substantial feedbacks to adaptation policy.

  3. When Top-Down Becomes Bottom Up: Behaviour of Hyperdense Howler Monkeys (Alouatta seniculus) Trapped on a 0.6 Ha Island

    OpenAIRE

    Gabriela Orihuela; John Terborgh; Natalia Ceballos; Kenneth Glander

    2014-01-01

    Predators are a ubiquitous presence in most natural environments. Opportunities to contrast the behaviour of a species in the presence and absence of predators are thus rare. Here we report on the behaviour of howler monkey groups living under radically different conditions on two land-bridge islands in Lago Guri, Venezuela. One group of 6 adults inhabited a 190-ha island (Danto) where they were exposed to multiple potential predators. This group, the control, occupied a home range of 23 ha a...

  4. Automated Linear Function Submission-Based Double Auction as Bottom-up Real-Time Pricing in a Regional Prosumers’ Electricity Network

    Directory of Open Access Journals (Sweden)

    Tadahiro Taniguchi

    2015-07-01

    Full Text Available A linear function submission-based double auction (LFS-DA mechanism for a regional electricity network is proposed in this paper. Each agent in the network is equipped with a battery and a generator. Each agent simultaneously becomes a producer and consumer of electricity, i.e., a prosumer, and trades electricity in the regional market at a variable price. In the LFS-DA, each agent uses linear demand and supply functions when they submit bids and asks to an auctioneer in the regional market. The LFS-DA can achieve an exact balance between electricity demand and supply for each time slot throughout the learning phase and was shown capable of solving the primal problem of maximizing the social welfare of the network without any central price setter, e.g., a utility or a large electricity company, in contrast with conventional real-time pricing (RTP. This paper presents a clarification of the relationship between the RTP algorithm derived on the basis of a dual decomposition framework and LFS-DA. Specifically, we proved that the changes in the price profile of the LFS-DA mechanism are equal to those achieved by the RTP mechanism derived from the dual decomposition framework, except for a constant factor.

  5. Factors controlling contrail cirrus optical depth

    Directory of Open Access Journals (Sweden)

    B. Kärcher

    2009-08-01

    Full Text Available Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field. An analytical microphysical cloud model is presented and validated that captures these processes. Many individual contrail cirrus are simulated that develop differently owing to the variability in the controlling factors, resulting in large samples of cloud properties that are statistically analyzed. Contrail cirrus development is studied over the first four hours past formation, similar to the ages of line-shaped contrails that were tracked in satellite imagery on regional scales. On these time scales, contrail cirrus optical depth and microphysical variables exhibit a marked variability, expressed in terms of broad and skewed probability distribution functions. Simulated mean optical depths at a wavelength of 0.55 μm range from 0.05-0.5 and a substantial fraction 20-50% of contrail cirrus stay subvisible (optical depth <0.02, depending on meteorological conditions.

    A detailed analysis based on an observational case study over the continental USA suggests that previous satellite measurements of line-shaped persistent contrails have missed about 89%, 50%, and 11% of contrails with optical depths 0-0.05, 0.05-0.1, and 0.1-0.2, respectively, amounting to 65% of contrail coverage of all optical depths. When comparing observations with simulations and when estimating the contrail cirrus climate impact, not only mean values but also the variability in optical depth and microphysical properties need to be considered.

  6. Factors controlling contrail cirrus optical depth

    Directory of Open Access Journals (Sweden)

    B. Kärcher

    2009-05-01

    Full Text Available Aircraft contrails develop into contrail cirrus by depositional growth and sedimentation of ice particles and horizontal spreading due to wind shear. Factors controlling this development include temperature, ice supersaturation, thickness of ice-supersaturated layers, and vertical gradients in the horizontal wind field. An analytical microphysical cloud model is presented and validated that captures these processes. Many individual contrail cirrus are simulated that develop differently owing to the variability in the controlling factors, resulting in large samples of cloud properties that are statistically analyzed. Contrail cirrus development is studied over the first four hours past formation, similar to the ages of contrails that were tracked in satellite imagery on regional scales. On these time scales, contrail cirrus optical depth and microphysical variables exhibit a marked variability, expressed in terms of broad and skewed probability distribution functions. Typical simulated mean optical depths at a wavelength of 0.55 μm are in the range 0.2–0.3. A substantial fraction 20–40% of contrail cirrus stay subvisible (optical depth <0.02. A detailed analysis suggests that previous satellite measurements of line-shaped persistent contrails have missed about 86% (35% of contrails with optical depth ≤0.05 (0.05–0.1, amounting to almost 50% of contrails of all optical depths. When comparing observations with simulations and when estimating the contrail cirrus climate impact, not only mean values but also the variability in optical depth and microphysical properties need to be considered.

  7. 浅谈自底向上的Shell脚本编程及效率优化%A Brief Talk about Bottom-up Shell Script Programming and Efficiency Optimization

    Institute of Scientific and Technical Information of China (English)

    江松波; 倪子伟

    2011-01-01

    Shell scripts run in the interpreter mode, which has always been inefficient. Inefficient design will further affect the efficiency performance of the Shell script. This paper analyzes the characteristics of Shell language and its applications and proposes a "bottom up to Shell scripting" idea based on the perspective of hierarchical design. At the same time, this paper puts forward a comprehensive method, that is from the "external system environment" to “internal execution model", to mastering Shell utilities.The case fully proves that the idea and methods about bottom-up Shell scripting can effectively improve the efficiency of the script.%低效的Shell脚本设计会进一步影响原本解释器模式下并不见长的程序运行效率,使其在面对大数据量文本分析时的资源和时间消:耗变得难以接受.本文通过分析Shell语言及其应用需求的特点,从分层设计的角度提出"自底向上进行Shen脚本编程"的理论,同时提出从"外部系统环境"到"内部执行模式"全面地掌握工具软件的方法.实例充分证明,自底向上的Shell脚本编程思想及方法能够有效提高脚本的执行效率.

  8. Efficient Research Design: Using Value-of-Information Analysis to Estimate the Optimal Mix of Top-down and Bottom-up Costing Approaches in an Economic Evaluation alongside a Clinical Trial.

    Science.gov (United States)

    Wilson, Edward C F; Mugford, Miranda; Barton, Garry; Shepstone, Lee

    2016-04-01

    In designing economic evaluations alongside clinical trials, analysts are frequently faced with alternative methods of collecting the same data, the extremes being top-down ("gross costing") and bottom-up ("micro-costing") approaches. A priori, bottom-up approaches may be considered superior to top-down approaches but are also more expensive to collect and analyze. In this article, we use value-of-information analysis to estimate the efficient mix of observations on each method in a proposed clinical trial. By assigning a prior bivariate distribution to the 2 data collection processes, the predicted posterior (i.e., preposterior) mean and variance of the superior process can be calculated from proposed samples using either process. This is then used to calculate the preposterior mean and variance of incremental net benefit and hence the expected net gain of sampling. We apply this method to a previously collected data set to estimate the value of conducting a further trial and identifying the optimal mix of observations on drug costs at 2 levels: by individual item (process A) and by drug class (process B). We find that substituting a number of observations on process A for process B leads to a modest £35,000 increase in expected net gain of sampling. Drivers of the results are the correlation between the 2 processes and their relative cost. This method has potential use following a pilot study to inform efficient data collection approaches for a subsequent full-scale trial. It provides a formal quantitative approach to inform trialists whether it is efficient to collect resource use data on all patients in a trial or on a subset of patients only or to collect limited data on most and detailed data on a subset. PMID:26762649

  9. Bottom Up Project Cost and Risk Modeling

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm along with its partners HRP Systems, End-to-End Analytics, and ARES Corporation (unfunded in Phase I), propose to develop a new solution for detailed data...

  10. Bottom-up Experiments and Concrete Utopias

    DEFF Research Database (Denmark)

    Andersson, Lasse

    2010-01-01

    Artiklen undersøger hvorledes brugerdrevne experimenter kan udfordre den standardiserede erhvervsorienterede udgave af Oplevelsesbyen og via eksperimentet stimulerer lokalt forankrede og demokratiske udgaver af en oplevelses- og vidensbaseret by....

  11. Milk bottom-up proteomics: method optimisation.

    Directory of Open Access Journals (Sweden)

    Delphine eVincent

    2016-01-01

    Full Text Available Milk is a complex fluid whose proteome displays a diverse set of proteins of high abundance such as caseins and medium to low abundance whey proteins such as ß-lactoglobulin, lactoferrin, immunoglobulins, glycoproteins, peptide hormones and enzymes. A sample preparation method that enables high reproducibility and throughput is key in reliably identifying proteins present or proteins responding to conditions such as a diet, health or genetics. Using skim milk samples from Jersey and Holstein-Friesian cows, we compared three extraction procedures which have not previously been applied to samples of cows’ milk. Method A (urea involved a simple dilution of the milk in a urea-based buffer, method B (TCA/acetone involved a trichloroacetic acid (TCA/acetone precipitation and method C (methanol/chloroform involved a tri-phasic partition method in chloroform/methanol solution. Protein assays, SDS-PAGE profiling, and trypsin digestion followed by nanoHPLC-electrospray ionisation-tandem mass spectrometry (nLC-ESI-MS/MS analyses were performed to assess their efficiency. Replicates were used at each analytical step (extraction, digestion, injection to assess reproducibility. Mass spectrometry (MS data are available via ProteomeXchange with identifier PXD002529. Overall 186 unique accessions, major and minor proteins, were identified with a combination of methods. Method C (methanol/chloroform yielded the best resolved SDS-patterns and highest protein recovery rates, method A (urea yielded the greatest number of accessions, and, of the three procedures, method B (TCA/acetone was the least compatible of all with a wide range of downstream analytical procedures. Our results also highlighted breed differences between the proteins in milk of Jersey and Holstein-Friesian cows.

  12. Bottom-up tailoring of photonic nanofibers

    DEFF Research Database (Denmark)

    Balzer, Frank; Madsen, Morten; Frese, Ralf; Schiek, Manuela; Tamulevicius, Thomas; Tamulevicius, Sigitas; Rubahn, Horst-Günter

    2008-01-01

    Aligned ensembles of nanoscopic nanofibers from organic molecules such as para-phenylenes for photonic applications can be fabricated by self-assembled molecular growth on a suited dielectric substrate. Epitaxy together with alignment due to electric surface fields determines the growth directions....... In this paper we demonstrate how aligned growth along arbitrary directions can be realized by depositing the molecules on a micro-structured and gold covered Silicon surface, consisting of channels and ridges. For the correct combination of ridge width and deposition temperature fibers grow...

  13. Big data from the bottom up

    OpenAIRE

    Couldry, Nick; Powell, Alison

    2014-01-01

    This short article argues that an adequate response to the implications for governance raised by ‘Big Data’ requires much more attention to agency and reflexivity than theories of ‘algorithmic power’ have so far allowed. It develops this through two contrasting examples: the sociological study of social actors used of analytics to meet their own social ends (for example, by community organisations) and the study of actors’ attempts to build an economy of information more open to civic interve...

  14. Promoting education from the bottom up

    Science.gov (United States)

    Page, Martin

    2010-02-01

    I am not an academic, just a foot soldier: I help out with the Children's University and as a Schools Science Ambassador, giving talks and demonstrations in physics. The recent £40m cuts in the budget of the UK's Science and Technology Facilities Council (January p6) have created quite a stir in the academic community, with talk of a "brain drain". Those in the penthouse should come down to the basement, where they would see just how thin and fragile the scientific foundation is.

  15. Bottom-up approach to spatial datamining

    OpenAIRE

    Künzi, Christophe; Stoffel, Kilian

    2013-01-01

    One of the goals of computer vision research is to design systems that provide human-like visual capabilities such that a certain environment can be sensed and interpreted to take appropriate actions. Among the different forms available to represent such an environment, the 3D point cloud (unstructured collection of points in a three dimensional space) rises a lot of challenging problems. Moreover, the number of 3D data collection drastically increased in recent years, as improvements in the ...

  16. Research and Development from the bottom up

    DEFF Research Database (Denmark)

    Brem, Alexander; Wolfram, P.

    2014-01-01

    ecological context or the growing interest of developed market firms in approaches from emerging markets. Hence, the presented framework supports further research in new paradigms for research and development (R&D) in developed market firms (DMFs), particularly in relation to emerging markets. This framework...... enables scholars to compare concepts from developed and emerging markets, to address studies specifically by using consistent terms, and to advance research into the concepts according their characterization....... introduced consisting of three core dimensions: sophistication, sustainability, and emerging market orientation. On the basis of these dimensions, analogies and distinctions between the terms are identified and general tendencies are explored such as the increasing importance of sustainability in social and...

  17. Mobile Handsets from the Bottom Up

    DEFF Research Database (Denmark)

    Wallis, Cara; Linchuan Qiu, Jack; Ling, Richard

    2013-01-01

    The setting could be a hole-in-the-wall that serves as a shop in a narrow alley in Guangzhou, a cart on a dusty street on the outskirts of Accra, a bustling marketplace in Mexico City, or a tiny storefront near downtown Los Angeles’ garment district. At such locales, men and women hawk an array o...... low-income, largely immigrant communities in cities in the developed world....

  18. Nonsquare Spectral Factorization for Nonlinear Control Systems

    NARCIS (Netherlands)

    Petersen, Mark A.; Schaft, Arjan J. van der

    2005-01-01

    This paper considers nonsquare spectral factorization of nonlinear input affine state space systems in continuous time. More specifically, we obtain a parametrization of nonsquare spectral factors in terms of invariant Lagrangian submanifolds and associated solutions of Hamilton–Jacobi inequalities.

  19. Colon cancer controls versus population controls in case-control studies of occupational risk factors

    Directory of Open Access Journals (Sweden)

    Sabroe Svend

    2004-04-01

    Full Text Available Abstract Background Since updated population registers do not exist in many countries it is often difficult to sample valid population controls from the study base to a case-control study. Use of patient controls is an alternative option if the exposure experience under study for these patients are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors. Methods The study was conducted from 1995 to 1997. Incident colon cancer controls (N = 428 aged 35–69 years with a histological verified diagnosis and population controls (N = 583 were selected. Altogether 254 (59% of the colon cancer controls and 320 (55% of the population controls were interviewed about occupational, medical and life style conditions. Results No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure to pesticides among colon cancer controls. Conclusions Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming.

  20. Probabilistic Analysis of an Automatic Power Factor Controller with variation in Power Factor

    OpenAIRE

    P K Bhatia; ROOSEL JAIN; GULSHAN TANEJA,

    2012-01-01

    In the present study, the probabilistic analysis of an automatic power factor controller (APFC) system working in industry/factory is investigated. The power factor correction of electrical loads and energy losses due to poor power factor are the problems common to all industrial companies. Therefore, the study of APFC unit is of greatimportance. Initially, the system is operative with controlled power factor. Then it may transit to state with power factor not controlled. On the failure of th...

  1. Optimization of Input Weighting Factors for Model Predictive Controller

    International Nuclear Information System (INIS)

    A model predictive control (MPC) method has been efficiently applied to APR-type reactor as a control bank controller for reactor power level and axial power distribution controls. MPC algorithm is to solve the optimization problem to minimize objective function over a future horizon. Normally, input weighting factors in objective function should be optimized to enhance the performance of controller. In this paper, input weighting factor has been determined by design of experiment (DOE) method

  2. Factors influencing the profitability of optimizing control systems

    International Nuclear Information System (INIS)

    Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)

  3. Correct primary structure assessment and extensive glyco-profiling of cetuximab by a combination of intact, middle-up, middle-down and bottom-up ESI and MALDI mass spectrometry techniques.

    Science.gov (United States)

    Ayoub, Daniel; Jabs, Wolfgang; Resemann, Anja; Evers, Waltraud; Evans, Catherine; Main, Laura; Baessmann, Carsten; Wagner-Rousset, Elsa; Suckau, Detlev; Beck, Alain

    2013-01-01

    The European Medicines Agency received recently the first marketing authorization application for a biosimilar monoclonal antibody (mAb) and adopted the final guidelines on biosimilar mAbs and Fc-fusion proteins. The agency requires high similarity between biosimilar and reference products for approval. Specifically, the amino acid sequences must be identical. The glycosylation pattern of the antibody is also often considered to be a very important quality attribute due to its strong effect on quality, safety, immunogenicity, pharmacokinetics and potency. Here, we describe a case study of cetuximab, which has been marketed since 2004. Biosimilar versions of the product are now in the pipelines of numerous therapeutic antibody biosimilar developers. We applied a combination of intact, middle-down, middle-up and bottom-up electrospray ionization and matrix assisted laser desorption ionization mass spectrometry techniques to characterize the amino acid sequence and major post-translational modifications of the marketed cetuximab product, with special emphasis on glycosylation. Our results revealed a sequence error in the reported sequence of the light chain in databases and in publications, thus highlighting the potency of mass spectrometry to establish correct antibody sequences. We were also able to achieve a comprehensive identification of cetuximab's glycoforms and glycosylation profile assessment on both Fab and Fc domains. Taken together, the reported approaches and data form a solid framework for the comparability of antibodies and their biosimilar candidates that could be further applied to routine structural assessments of these and other antibody-based products. PMID:23924801

  4. A top-down / bottom-up approach for multi-actors and multi-criteria assessment of mining projects for sustainable development. Application on Arlit Uranium mines (Niger)

    International Nuclear Information System (INIS)

    This thesis aims to appraise the relevance of using an hybrid top-down / bottom-up approach to evaluate mining projects in the perspective of sustainable development. With the advent of corporate social responsibility and sustainable development concepts, new social expectations have appeared towards companies that go beyond a sole requirement of profit earning capacity. If companies do not answer to these expectations, they risk to lose their social legitimacy. Traditionally associated with social, environmental, economical and political impacts and risks, mining activity is particularly concerned by these new issues. Whereas mineral resources needs have never been so high, mining companies are now expected to limit their negative effects and to take into account their different audiences' expectations in order to define, together, the terms of their social license to operate. Considering the diversity of issues, scales, actors and contexts, the challenge is real and necessitates tools to better understand issues and to structure dialogues. Based on the Uranium mines of Arlit (Niger) case study, this work shows that associating participatory approaches to structuration tools and literature propositions, appears as an efficient formula to better organize issues diversity and to build a structured dialogue between mining companies and their stakeholders. First Part aims to present the theoretical, institutional and sectorial contexts of the thesis. Second Part exposes work and results of the evaluation carried out in Niger. And, Third Part, shows the conclusions that can be derived from this work and presents a proposal for an evaluation framework, potentially applicable to other mining sites. (author)

  5. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging.

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-14

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM(+) on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 ± 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection. PMID:26891173

  6. Soft-Starting Power-Factor Motor Controller

    Science.gov (United States)

    Nola, F. J.

    1983-01-01

    Three-phase power-factor controller with soft start is based on earlier version that does not control starting transients. Additional components serve to turn off "run" command signal and substitute gradual startup command signal during preset startup interval. Improved controller reduces large current surge that usually accompanies starting. Controller applies power smoothly, without causing motor vibrations.

  7. PMBLDC motor drive with power factor correction controller

    DEFF Research Database (Denmark)

    George, G.J.; Ramachandran, Rakesh; Arun, N.

    2012-01-01

    This paper presents a boost converter configuration, control scheme and design of single phase power factor controller for permanent magnet brushless DC motor (PMBLDCM) drive. PMBLDC motors are the latest choice of researchers, due to the high efficiency, silent operation, compact size, high...... reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase with...... supply voltage. It uses a boost converter to obtain unity power factor with improved performance. The system includes a speed controller for PMBLDC drive and a voltage controller for boost converter.. The voltage or speed controllers can be realized using proportional integral (PI) controller...

  8. Human factors in the control room

    International Nuclear Information System (INIS)

    The performance of Ontario Hydro's CANDU-based nuclear power plants has been excellent to date. Human factors engineering has been very much a part of the CANDU reactor design and development process. From the beginning operations staff has worked closely with designers. During commissioning and operation faults and errors are recorded and reported to the designers. A central group also carries out long-term evaluations of experience gained in nuclear plants around the world. The increasing complexity of nuclear power plants may in the short term increase operator's expectations for pay and job conditions, and in the longer term limit the number of people who want the job. Human factors engineering should minimize the complexity of systems, their interrelationships, the operator's tasks, and the environment in which they perform. Keep it simple

  9. HUMAN FACTORS GUIDANCE FOR CONTROL ROOM EVALUATION

    International Nuclear Information System (INIS)

    The Human-System Interface Design Review Guideline (NUREG-0700, Revision 1) was developed by the US Nuclear Regulatory Commission (NRC) to provide human factors guidance as a basis for the review of advanced human-system interface technologies. The guidance consists of three components: design review procedures, human factors engineering guidelines, and a software application to provide design review support called the ''Design Review Guideline.'' Since it was published in June 1996, Rev. 1 to NUREG-0700 has been used successfully by NRC staff, contractors and nuclear industry organizations, as well as by interested organizations outside the nuclear industry. The NRC has committed to the periodic update and improvement of the guidance to ensure that it remains a state-of-the-art design evaluation tool in the face of emerging and rapidly changing technology. This paper addresses the current research to update of NUREG-0700 based on the substantial work that has taken place since the publication of Revision 1

  10. Drug treatment-related factors of inadequate seizure control.

    NARCIS (Netherlands)

    Handoko, K.B.; Rijkom, JE Zwart-van; Visee, H.F.; Hermens, W.A.; Hekster, Y.A.; Egberts, T.C.G.

    2008-01-01

    To optimize seizure control it is important to identify modifiable factors. We conducted a case-control study to explore to what extent drug treatment-related factors are associated with seizures. Eighty-six patients with epilepsy were evaluated: 45 cases (recently experienced a seizure) and 41 cont

  11. Coal reservoir permeability and main geological controlling factors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.; Chen, X. [North China Petroleum Administration, Zhengzhou (China). Xinxing Petroleum Company

    2002-02-01

    Based on the study of pilot areas of Liulin and Anyang in North China, the coal reservoir permeability and the main geological controlling factors have been thoroughly researched. The results show that the development degree of cleats is the major controlling factor, followed by the effective stress, exokinetic fractures and the coal body structure. On the other hand, the cleat development is controlled by the coal rank and vitrinite content. 3 figs.

  12. Bottom-up electrochemical preparation of solid-state carbon nanodots directly from nitriles/ionic liquids using carbon-free electrodes and the applications in specific ferric ion detection and cell imaging

    Science.gov (United States)

    Niu, Fushuang; Xu, Yuanhong; Liu, Mengli; Sun, Jing; Guo, Pengran; Liu, Jingquan

    2016-03-01

    Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often required. Herein, solid-state C-dots were simply prepared by bottom-up EC carbonization of nitriles (e.g. acetonitrile) in the presence of an ionic liquid [e.g. 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6)], using carbon-free electrodes. Due to the positive charges of BMIM+ on the C-dots, the final products presented in a precipitate form on the cathode, and the unreacted nitriles and BMIMPF6 can be easily removed by simple vacuum filtration. The as-prepared solid-state C-dots can be well dispersed in an aqueous medium with excellent photoluminescence properties. The average size of the C-dots was found to be 3.02 +/- 0.12 nm as evidenced by transmission electron microscopy. Other techniques such as UV-vis spectroscopy, fluorescence spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy were applied for the characterization of the C-dots and to analyze the possible generation mechanism. These C-dots have been successfully applied in efficient cell imaging and specific ferric ion detection.Carbon nanodots (C-dots), a new type of potential alternative to conventional semiconductor quantum dots, have attracted numerous attentions in various applications including bio-chemical sensing, cell imaging, etc., due to their chemical inertness, low toxicity and flexible functionalization. Various methods including electrochemical (EC) methods have been reported for the synthesis of C-dots. However, complex procedures and/or carbon source-containing electrodes are often

  13. Integrating top-down and bottom-up approaches to design a cost-effective and equitable programme of measures for adaptation of a river basin to global change

    Science.gov (United States)

    Girard, Corentin; Rinaudo, Jean-Daniel; Pulido-Velazquez, Manuel

    2016-04-01

    Adaptation to the multiple facets of global change challenges the conventional means of sustainably planning and managing water resources at the river basin scale. Numerous demand or supply management options are available, from which adaptation measures need to be selected in a context of high uncertainty of future conditions. Given the interdependency of water users, agreements need to be found at the local level to implement the most effective adaptation measures. Therefore, this work develops an approach combining economics and water resources engineering to select a cost-effective programme of adaptation measures in the context of climate change uncertainty, and to define an equitable allocation of the cost of the adaptation plan between the stakeholders involved. A framework is developed to integrate inputs from the two main approaches commonly used to plan for adaptation. The first, referred to as "top-down", consists of a modelling chain going from global greenhouse gases emission scenarios to local hydrological models used to assess the impact of climate change on water resources. Conversely, the second approach, called "bottom-up", starts from assessing vulnerability at the local level to then identify adaptation measures used to face an uncertain future. The methodological framework presented in this contribution relies on a combination of these two approaches to support the selection of adaptation measures at the local level. Outcomes from these two approaches are integrated to select a cost-effective combination of adaptation measures through a least-cost optimization model developed at the river basin scale. The performances of a programme of measures are assessed under different climate projections to identify cost-effective and least-regret adaptation measures. The issue of allocating the cost of the adaptation plan is considered through two complementary perspectives. The outcome of a negotiation process between the stakeholders is modelled through

  14. Risk factors for caries - control and prevention

    Directory of Open Access Journals (Sweden)

    Melida Hasanagić

    2008-08-01

    Full Text Available Objectives. To investigate a prevalence of caries, filled permanentand extracted permanent teeth, as well as caries risk factors inschool children aged 7, 9 and 11.Methods. The survey included 800 children (296 children aged7; 254 children aged 9 and 250 children aged 11 from the MostarMunicipality, 400 of them living in both rural and urban areas.A dental mirror and standard light of dental chair were used forexamination. The DMF index (Dental Caries, Missing Teeth andFilled Teeth was determined, as well as failure in keeping teethhygiene, sugar intake with food, and incidence of oral cavity infection.Results. The dental state of permanent teeth in children aged 7and 9 has shown significant difference between the children fromrural and urban areas (p < 0,001. Out of 2,698 and 2,790 permanentteeth in children aged 11 from rural and urban areas, 1,086(40,25 % and 884 (31.68 % had caries, respectively (p < 0.01.The difference between these groups of children has been foundin relation to the index of oral hygiene too (p < 0.05.Conclusion. An identification of risk groups for getting caries wasvery important and could help health and social structures to maintaintheir programs in order to improve oral health.

  15. A top-down / bottom-up approach for multi-actors and multi-criteria assessment of mining projects for sustainable development. Application on Arlit Uranium mines (Niger); Une demarche Top-Down / Bottom-Up pour l'evaluation en termes multicriteres et multi-acteurs des projets miniers dans l'optique du developpement durable. Application sur les mines d'Uranium d'Arlit (Niger)

    Energy Technology Data Exchange (ETDEWEB)

    Chamaret, A

    2007-06-15

    This thesis aims to appraise the relevance of using an hybrid top-down / bottom-up approach to evaluate mining projects in the perspective of sustainable development. With the advent of corporate social responsibility and sustainable development concepts, new social expectations have appeared towards companies that go beyond a sole requirement of profit earning capacity. If companies do not answer to these expectations, they risk to lose their social legitimacy. Traditionally associated with social, environmental, economical and political impacts and risks, mining activity is particularly concerned by these new issues. Whereas mineral resources needs have never been so high, mining companies are now expected to limit their negative effects and to take into account their different audiences' expectations in order to define, together, the terms of their social license to operate. Considering the diversity of issues, scales, actors and contexts, the challenge is real and necessitates tools to better understand issues and to structure dialogues. Based on the Uranium mines of Arlit (Niger) case study, this work shows that associating participatory approaches to structuration tools and literature propositions, appears as an efficient formula to better organize issues diversity and to build a structured dialogue between mining companies and their stakeholders. First Part aims to present the theoretical, institutional and sectorial contexts of the thesis. Second Part exposes work and results of the evaluation carried out in Niger. And, Third Part, shows the conclusions that can be derived from this work and presents a proposal for an evaluation framework, potentially applicable to other mining sites. (author)

  16. 应用于Bottom-up蛋白质鉴定的质谱数据采集策略研究进展%Data Acquisition Strategy for Mass Spectrometers Applied to Bottom-up-based Protein Identification

    Institute of Scientific and Technical Information of China (English)

    徐长明; 张纪阳; 张伟; 谢红卫

    2013-01-01

    The high complexity of the proteome has brought great challenges to mass spectrometry-based protein identification.The technical requirements continuously forward the development of mass spectrometry.The advances in hardware and software of instrument platform provide more choices and supports for protein identification.However,it is necessary to design high-quality data acquisition strategy,which is heavyly dependent on the specific biological problem and the sample,to make the best use of the performance of the instrument.Here,the data acquisition strategy that has been developed for mass spectrometers in high throughput protein identification was reviewed.The simple repetitions,ion exclusion,ion inclusion,online intelligent data acquisition and segmented scanning technology for Bottom-up strategy were highlighted,and the impact of these strategies on the protein identification was concerned.Finally,the advantages and disadvantages of various strategies were summarized,and the future directions of developing the data acquisition strategy for mass spectrometers were discussed.%蛋白质组的高度复杂性给基于质谱的蛋白质鉴定提出了很大的挑战.技术需求促进质谱技术不断向前发展.仪器平台在软硬件方面的进步,为高通量蛋白质鉴定提供了更多选择和支撑.但是,仪器性能的充分发挥,还需要根据生物学问题的需求和分析样本的特性,设计高质量的数据采集策略.本文对目前高通量蛋白质鉴定中已开发的质谱数据采集策略进行了综述,重点介绍了Bottom-up策略中使用的简单重复、离子排除和监测、在线智能化扫描和分段扫描等技术,并关注了这些策略对高通量蛋白质鉴定的影响,总结了各种策略的优缺点并展望了其未来发展方向.

  17. Human factors survey of advanced instrumentation and controls

    International Nuclear Information System (INIS)

    A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I ampersand C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I ampersand C. Fifteen potential human factors problems were identified. They include: the need for an advanced I ampersand C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I ampersand C; and operator acceptance and trust. 11 refs., 1 tab

  18. Human factors survey of advanced instrumentation and controls

    Energy Technology Data Exchange (ETDEWEB)

    Carter, R.J.

    1989-01-01

    A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I C. Fifteen potential human factors problems were identified. They include: the need for an advanced I C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I C; and operator acceptance and trust. 11 refs., 1 tab.

  19. Taking account of human factors in control-room design

    International Nuclear Information System (INIS)

    Since the Three Mile Island accident two ways for improving the Human-Machine Interface have mainly been followed: the development of computerized operator aids in existing control-rooms and the design of advanced control-rooms. Insufficient attention paid to human factors in the design of operator aids has generally led to these aids being neglected or unused by their potential users. While for the design of advanced control-rooms efforts have been made for dealing with human factors in more extensive way. Based upon this experience, a general method for taking account of human factors in a control-room design has been devised and is described in this paper. (author)

  20. Three-phase power factor controller with induced EMF sensing

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A power factor controller for an ac induction motor is provided which is of the type comprising thyristor switches connected in series with the motor, phase detectors for sensing the motor current and voltage and providing an output proportional to the phase difference between the motor voltage and current, and a control circuit, responsive to the output of the phase detector and to a power factor command signal, for controlling switching of the thyristor. The invention involves sensing the induced emf produced by the motor during the time interval when the thyristor is off and for producing a corresponding feedback signal for controlling switching of the thyristor. The sensed emf is also used to enhance soft starting of the motor.

  1. Neurotrophic factor control of satiety and body weight.

    Science.gov (United States)

    Xu, Baoji; Xie, Xiangyang

    2016-05-01

    Energy balance - that is, the relationship between energy intake and energy expenditure - is regulated by a complex interplay of hormones, brain circuits and peripheral tissues. Leptin is an adipocyte-derived cytokine that suppresses appetite and increases energy expenditure. Ironically, obese individuals have high levels of plasma leptin and are resistant to leptin treatment. Neurotrophic factors, particularly ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), are also important for the control of body weight. CNTF can overcome leptin resistance in order to reduce body weight, although CNTF and leptin activate similar signalling cascades. Mutations in the gene encoding BDNF lead to insatiable appetite and severe obesity. PMID:27052383

  2. Risk factors for ovarian cancer: a case-control study.

    OpenAIRE

    Booth, M.; Beral, V; SMITH, P.

    1989-01-01

    A hospital-based case-control study of ovarian cancer was conducted in London and Oxford between October 1978 and February 1983. Menstrual characteristics, reproductive and contraceptive history and history of exposure to various environmental factors were compared between 235 women with histologically diagnosed epithelial ovarian cancer and 451 controls. High gravidity, hysterectomy, female sterilisation and oral contraceptive use were associated with a reduced risk of ovarian cancer. Infert...

  3. Potential risk factors for diabetic neuropathy: a case control study

    Directory of Open Access Journals (Sweden)

    Nooraei Mahdi

    2005-12-01

    Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

  4. Dominant factors in controlling marine gas pools in South China

    Institute of Scientific and Technical Information of China (English)

    XU Sihuang; W.Lynn Watney

    2007-01-01

    In marine strata from Sinian to Middle Triassic in South China,there develop four sets of regional and six sets of local source rocks,and ten sets of reservoir rocks.The occurrence of four main formation periods in association with five main reconstruction periods,results in a secondary origin for the most marine gas pools in South China.To improve the understanding of marine gas pools in South China with severely deformed geological background,the dominant control factors are discussed in this paper.The fluid sources,including the gas cracked from crude oil,the gas dissolved in water,the gas of inorganic origin,hydrocarbons generated during the second phase,and the mixed pool fluid source,were the most significant control factors of the types and the development stage of pools.The period of the pool formation and the reconstruction controlled the pool evolution and the distribution on a regional scale.Owing to the multiple periods of the pool formation and the reconstruction,the distribution of marine gas pools was complex both in space and in time,and the gas in the pools is heterogeneous.Pool elements,such as preservation conditions,traps and migration paths,and reservoir rocks and facies,also served as important control factors to marine gas pools in South China.Especially,the preservation conditions played a key role in maintaining marine oil and gas accumulations on a regional or local scale.According to several dominant control factors of a pool,the pool-controlling model can be constructed.As an example,the pool-controlling model of Sinian gas pool in Weiyuan gas field in Sichuan basin was summed up.

  5. Dominant factors in controlling marine gas pools in South China

    Science.gov (United States)

    Xu, S.; Watney, W.L.

    2007-01-01

    In marine strata from Sinian to Middle Triassic in South China, there develop four sets of regional and six sets of local source rocks, and ten sets of reservoir rocks. The occurrence of four main formation periods in association with five main reconstruction periods, results in a secondary origin for the most marine gas pools in South China. To improve the understanding of marine gas pools in South China with severely deformed geological background, the dominant control factors are discussed in this paper. The fluid sources, including the gas cracked from crude oil, the gas dissolved in water, the gas of inorganic origin, hydrocarbons generated during the second phase, and the mixed pool fluid source, were the most significant control factors of the types and the development stage of pools. The period of the pool formation and the reconstruction controlled the pool evolution and the distribution on a regional scale. Owing to the multiple periods of the pool formation and the reconstruction, the distribution of marine gas pools was complex both in space and in time, and the gas in the pools is heterogeneous. Pool elements, such as preservation conditions, traps and migration paths, and reservoir rocks and facies, also served as important control factors to marine gas pools in South China. Especially, the preservation conditions played a key role in maintaining marine oil and gas accumulations on a regional or local scale. According to several dominant control factors of a pool, the pool-controlling model can be constructed. As an example, the pool-controlling model of Sinian gas pool in Weiyuan gas field in Sichuan basin was summed up. ?? Higher Education Press and Springer-Verlag 2007.

  6. Responses of Lens esculenta Moench to controlled environmental factors

    NARCIS (Netherlands)

    Saint-Clair, P.M.

    1972-01-01

    Many experiments were undertaken to study the responses of the lentil cultivars 'Large blonde' and 'Anicia' to controlled environmental factors. They covered different aspects of the physiology and the ecology of the crop.The orientation experiments (2) involved germination and depth of sowing. The

  7. Designing Simulation Experiments with Controllable and Uncontrollable Factors

    DEFF Research Database (Denmark)

    Dehlendorff, Christian; Kulahci, Murat; Andersen, Klaus Kaae

    In this study we propose a new method for designing computer experiments inspired by the split plot designs used in physical experimentation. The basic layout is that each set of controllable factor settings corresponds to a whole plot for which a number of subplots, each corresponding to one...... should be guaranteed. Our proposed method allows for a large number of uncontrollable and controllable settings to be run in a limited number of runs while uniformly covering the design space for the uncontrollable factors....... combination of settings of the uncontrollable factors, is employed. The caveat is a desire that the subplots within each whole plot cover the design space uniformly. A further desire is that in the combined design, where all experimental runs are considered at once, the uniformity of the design space coverage...

  8. REPRODUCTIVE FACTORS AND COLORECTAL CANCER RISK. Case - control study.

    Directory of Open Access Journals (Sweden)

    Adriana Ruseva

    2015-02-01

    Full Text Available Colorectal cancer is one of the most common cancers worldwide. The role of the female sex hormones in the etiology of the disease is very intriguing. Reproductive factors are surrogate measure of lifetime exposition to the sex hormones. Purpose: Our aim is to investigate the association between the reproductive factors and colorectal carcinoma risk. Materials and methods: We include 234 Bulgarian women in our study – 117 cases with colorectal cancer and the same number of healthy controls. Cases are divided into three groups according to the localization of the tumor. We conduct case-control study, using questionnaires about reproductive factors. We use the following statistical methods – descriptive, variational analysis, binary logistic regression. Results: We observed that only the age at menopause is associated with colorectal cancer risk, and this factor has strongest protective effect in the proximal colon (95% CI - 0,051-0,781, OR – 0,200, p – 0,021. Conclusion: Analyzing our data we observed that among Bulgarian women the only reproductive factor that show association with the risk of colorectal cancer is the age at menopause.

  9. Factores de necesidad asociados al uso adecuado del control prenatal

    Directory of Open Access Journals (Sweden)

    Clarybel Miranda Mellado

    2016-07-01

    Full Text Available Introducción: Por las implicaciones sociales de la mortalidad y morbilidad materna es importante determinar los factores de necesidad que influyen en el uso adecuado del control prenatal en gestantes de Sincelejo. Materiales y Métodos: Estudio analítico de corte transversal, que incluyó 730 gestantes, seleccionadas mediante muestreo aleatorio por conglomerados, de las comunas de la ciudad. La información fue recolectada por medio de una encuesta sociodemográfica, una ficha de uso de control prenatal y un Cuestionario para evaluar los factores de necesidad  propuestos por el Modelo de Promoción de la Salud de Nola Pender. Las gestantes fueron contactadas en sus domicilios y diligenciaron los instrumentos. Los datos fueron analizados aplicando estadística descriptiva e inferencial para determinar las asociaciones entre variables. Resultados: El 97,7% (713 de las gestantes asistía al control prenatal, con una mediana de 4 controles prenatales. Un 2,3% (17 no lo habían iniciado al momento de la encuesta y 24,4% (178 hizo uso inadecuado. El 80,7% (589 de las gestantes califican su estado de salud como bueno o muy bueno, 94,8% (692 percibieron beneficios del control prenatal. Se encontró asociación significativa entre la percepción de beneficios y el uso adecuado de control prenatal [OR=5,5 (IC 95%: 2,8 - 10,8]. Discusión y Conclusiones: La percepción que las mujeres tienen sobre los buenos resultados que reporta la asistencia al control prenatal, es el principal factor que puede explicar la adherencia al control y el cumplimiento regular de las consultas. Cómo citar este artículo: Miranda C, Castillo IY. Factores de necesidad asociados al uso adecuado del control prenatal. Rev Cuid. 2016; 7(2: 1345-51. http://dx.doi.org/10.15649/cuidarte.v7i2.340

  10. Multiple Sclerosis Associated Risk Factors: A Case-Control Study

    OpenAIRE

    POOROLAJAL, Jalal; Mazdeh, Mehrdokht; Saatchi, Mohammad; TALEBI GHANE, Elaheh; BIDERAFSH, Azam; LOTFI, Bahar; Mohammad FERYADRES; PAJOHI, Khabat

    2015-01-01

    Background: Hamadan Province is one of the high-risk regions in Iran for Multiple sclerosis (MS). A majority of the epidemiological studies conducted in Iran addressing MS are descriptive. This study was conducted to assess MS and its associated risk factors in Hamadan Province, the west of Iran.Methods: This case-control study compared 100 patients with MS (case group) and 100 patients with acute infectious diseases (control group) from September 2013 to March 2014. A checklist was used to a...

  11. Human factors in aviation: Terminal control area boundary conflicts

    Science.gov (United States)

    Monan, William P.

    1989-01-01

    Air-to-air conflicts in the vicinity of Terminal Control Area (TCA) boundaries were studied to obtain a better understanding of the causal dynamics of these events with particular focus on human factor issues. The study dataset consisted of 381 Instrument Flight Rules/Visual Flight Rules (IFR/VFR) traffic conflicts in airspace layers above TCA ceiling and below TCA floors; 213 reports of incursions in TCA terminal airspace by VFR aircraft, of which 123 resulted in conflicts; and an additional set of reports describing problems with Air Traffic Control (ATC) services in and around TCAs. Results and conclusions are detailed.

  12. Factores de necesidad asociados al uso adecuado del control prenatal

    OpenAIRE

    Clarybel Miranda Mellado; Irma Castillo Avila

    2016-01-01

    Introducción: Por las implicaciones sociales de la mortalidad y morbilidad materna es importante determinar los factores de necesidad que influyen en el uso adecuado del control prenatal en gestantes de Sincelejo. Materiales y Métodos: Estudio analítico de corte transversal, que incluyó 730 gestantes, seleccionadas mediante muestreo aleatorio por conglomerados, de las comunas de la ciudad. La información fue recolectada por medio de una encuesta sociodemográfica, una ficha de uso de control p...

  13. Predictive factors of seizure control in childhood onset epilepsy

    OpenAIRE

    Eli Shahar; Jacob Genizi

    2008-01-01

    Background: Prediction of the long-term outcomes of childhood-onset epilepsy remains crucial for the future well-being of the affected children and their families and for planning proper therapeutic and educational programs. Objective: To identify and analyze the early predictive factors of seizure control in childhood-onset epilepsies referred at the age of 1 month up to the age of 18 years to the Epilepsy Service at the Meyer Children Hospital, Rambam Medical Center, Haifa, Israel. Materia...

  14. Macrophage migration inhibitory factor: controller of systemic inflammation

    OpenAIRE

    Larson, Douglas F.; Horak, Katherine

    2006-01-01

    Macrophage migration inhibitory factor (MIF) is a cytokine that is secreted by the anterior pituitary and immune cells in response to surgical stress, injury, and sepsis. This cytokine appears to be a critical regulator of the inflammatory pathways, leading to systemic inflammatory response syndrome and subsequent multiple organ dysfunction syndrome. This report provides an integrated scheme describing the manner by which MIF controls the neurohormonal response and the adaptive immune system,...

  15. The Current State of Controller Roles : Underlying Social Factors and Identity Control

    OpenAIRE

    Holm, Stefan; Thorstensson, Dag

    2013-01-01

    The aim of this thesis is to gather insights on the underlying social factors behind the current state of controller roles in a multinational enterprise. Additionally, the thesis explores the possibility of managing perceptions and expectations of controller roles, in accordance to corporate business objectives. In order to do this, theoretical concepts of Role Theory, Boundary Spanning and Identity Control were utilized. This paper has a qualitative research design and is based on an embedde...

  16. Factors Controlling the Distribution of Trace Metals in Macroalgae

    Institute of Scientific and Technical Information of China (English)

    王宝利; 刘丛强

    2004-01-01

    This paper presents the concentrations of trace metals (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb) in macroalgae from five areas. Significant differences were noticed in trace metal concentration in macroalgae, and a large range of variations between the minimum and maximum concentrations of trace metals was found. Trace metals detected in macroalgae generally occur in adsorbed and absorbed forms. Environmental and biological factors jointly control the trace metal compositions and concentrations in macroalgae. The complexity and variation of these factors cause significant differences in trace metal concentrations in macroalgae. Environmental factors play a more important role in controlling trace metal compositions and concentrations when external available trace metals are beyond requirement for algal metabolism and growth, especially for non-essential trace metals; however, when the external available trace metals just satisfy the needs of algal metabolism and growth, biological factors would play a more important role, especially for essential trace metals. Interactions among the trace metals can also influence their compositions and concentrations in macroalgae. It is also discussed how to make macroalgae as an excellent biomonitor for trace metals.

  17. A human factors approach to range scheduling for satellite control

    Science.gov (United States)

    Wright, Cameron H. G.; Aitken, Donald J.

    1991-01-01

    Range scheduling for satellite control presents a classical problem: supervisory control of a large-scale dynamic system, with unwieldy amounts of interrelated data used as inputs to the decision process. Increased automation of the task, with the appropriate human-computer interface, is highly desirable. The development and user evaluation of a semi-automated network range scheduling system is described. The system incorporates a synergistic human-computer interface consisting of a large screen color display, voice input/output, a 'sonic pen' pointing device, a touchscreen color CRT, and a standard keyboard. From a human factors standpoint, this development represents the first major improvement in almost 30 years to the satellite control network scheduling task.

  18. Understanding disease control: influence of epidemiological and economic factors

    CERN Document Server

    Oles, Katarzyna; Kleczkowski, Adam

    2011-01-01

    We present a local spread model of disease transmission on a regular network and compare different control options ranging from treating the whole population to local control in a well-defined neighborhood of an infectious individual. Comparison is based on a total cost of epidemic, including cost of palliative treatment of ill individuals and preventive cost aimed at vaccination or culling of susceptible individuals. Disease is characterized by pre- symptomatic phase which makes detection and control difficult. Three general strategies emerge, global preventive treatment, local treatment within a neighborhood of certain size and only palliative treatment with no prevention. The choice between the strategies depends on relative costs of palliative and preventive treatment. The details of the local strategy and in particular the size of the optimal treatment neighborhood weakly depends on disease infectivity but strongly depends on other epidemiological factors. The required extend of prevention is proportiona...

  19. Cooperative research for human factors review of advanced control rooms

    International Nuclear Information System (INIS)

    This project has been performed as cooperative research between KAERI and USNRC. Human factors issues related to soft controls, which is one of key features of advanced HSI, are identified in this project. The issues are analyzed for the evaluation approaches in either experimental or analytical ways. Also, issues requiring additional researches for the evaluation of advanced HSI are identified in the areas of advanced information systems design, computer-based procedure systems, soft controls, human systems interface and plant modernization process, and maintainability of digital systems. The issues are analyzed to discriminate the urgency of researches on it to high, medium, and low levels in consideration of advanced HSI development status in Korea, and some of the issues that can be handled by experimental researches are identified. Additionally, an experimental study is performed to compare operator's performance on human error detection in advanced control rooms vs. in conventional control rooms. It is found that advanced control rooms have several design characteristics hindering operator's error detection performance compared to conventional control rooms

  20. Based on Multi-Factors Grey Prediction Control for Elevator Velocity Modulation

    OpenAIRE

    Jiming Wang; Jin Ning; Ye Fei

    2012-01-01

    This paper uses the double-factors grey prediction and the fuzzy controller for the elevator car speed control. We introduce double-factors grey control to predict car vibration for elevator speed during the operation. Simulation results show that based on multi-factors gray prediction fuzzy PI control for elevator velocity modulation system closer than simple gray fuzzy PI control elevator speed control system to the actual operation. The control effect of double factors grey fuzzy PI contro...

  1. Risk Factors For Ectopic Pregnancy : A Case Control Study

    Directory of Open Access Journals (Sweden)

    Deshmukh J.S

    1999-01-01

    Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

  2. Autoregulatory systems controlling translation factor expression: Thermostat-like control of translational accuracy

    OpenAIRE

    Betney, Russell; de Silva, Eric; Krishnan, Jawahar; Stansfield, Ian

    2010-01-01

    In both prokaryotes and eukaryotes, the expression of a large number of genes is controlled by negative feedback, in some cases operating at the level of translation of the mRNA transcript. Of particular interest are those cases where the proteins concerned have cell-wide function in recognizing a particular codon or RNA sequence. Examples include the bacterial translation termination release factor RF2, initiation factor IF3, and eukaryote poly(A) binding protein. The regulatory loops that c...

  3. Quality factor control in a lasing microcavity model

    Science.gov (United States)

    Triandaf; Schwartz

    2000-04-01

    We consider a dynamics model of lasing microcavities, a class of optical resonators (1-10 &mgr;m in diameter) used in microlasers and for optical coupling of optical fibers. Inside such a cavity light circulates around the perimeter and is trapped by internal reflection. This is known as "whispering gallery" or high-Q modes. The cavity is a deformable cylindrical (or spherical) dielectric and at certain deformations light can escape by refraction. The quality of the resonator or Q factor, is defined as Q=omegatau, where tau is the escape time and omega is the frequency of light. We show that by appropriately deforming the cavity, the Q factor can be controlled by prolonging or shortening the average length of time spent by light trajectories inside the cavity. PMID:11088138

  4. Revisiting factors controlling methane emissions from high-Arctic tundra

    DEFF Research Database (Denmark)

    Mastepanov, M.; Sigsgaard, Charlotte; Tagesson, Håkan Torbern;

    2013-01-01

    known factors controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late......The northern latitudes are experiencing disproportionate warming relative to the mid-latitudes, and there is growing concern about feedbacks between this warming and methane production and release from high-latitude soils. Studies of methane emissions carried out in the Arctic, particularly those......-in periods. The measurements show clear seasonal dynamics in methane emission. The start of the growing season and the increase in CH4 fluxes were strongly related to the date of snowmelt. Within each particular growing season, CH4 fluxes were highly correlated with the soil temperature (R-2 > 0.75), which...

  5. Coal reservoir permeability and its controlled factors in China

    Energy Technology Data Exchange (ETDEWEB)

    Ye, J.; Shi, B.; Zhang, C. [China Administration Bureau of Coal Geology (China). Exploration Branch No. 1

    1999-04-01

    Based on most of the well-testing data in China since the 1990's, the permeability of the coal reservoir and the controlling factors in the major CBM-accumulating districts and zones were objectively evaluated. It was found that the coal reservoir's permeability in China is generally lower than that in America and there is a certain regional distribution rules. The permeability is lower in the eastern part of North China CBM-accumulating province than that in the west, and is lower in Northeast China's and South China's CBM-accumulating provinces than that in North China. Ground stress is the major factor which influences the coal reservoir's permeability. The distribution of the permeability with the burial depth of the coal reservoirs seems to be the function of the stress. 5 refs., 6 figs.

  6. Frequency control system based on power factor control of asynchronous motor

    Institute of Scientific and Technical Information of China (English)

    MENG Qing-chun; YANG Fei-xia; REN Zhi-ling

    2005-01-01

    Deduced the relationship between the power factor (PF) and the angular frequency according to the simplified equivalent circuit of asynchronous motor, forming a power factor auto-control system. An anti-interference circuit was also introduced in the middle voltage link of inverter to avoid the shift of the optimum PF point caused by the change of the load and the reliable run of the control system was assured. The experiment results show that it has a good self-adaptation in the whole scope of speed adjustment and an obvious economization on energy while it runs under load.

  7. Multiple Sclerosis Associated Risk Factors: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Jalal POOROLAJAL

    2015-11-01

    Full Text Available Background: Hamadan Province is one of the high-risk regions in Iran for Multiple sclerosis (MS. A majority of the epidemiological studies conducted in Iran addressing MS are descriptive. This study was conducted to assess MS and its associated risk factors in Hamadan Province, the west of Iran.Methods: This case-control study compared 100 patients with MS (case group and 100 patients with acute infectious diseases (control group from September 2013 to March 2014. A checklist was used to assess the demographic, medical, and family history of the patients. The Friedman-Rosenman questionnaire was also used to assess personality type. Statistical analysis was performed using logistic regression model with Stata 11 software program.Results: The adjusted odds ratio (OR estimate of MS was 4.37 (95% CI: 2.33, 8.20 for females compared to males; 0.15 (95% CI: 0.06, 0.43 for people aged above 50 years compared to aged 14 to 29 years; 0.44 (95% CI: 0.21, 0.91 for overweight or obese people compared to normal weights. Crude OR indicated a significant association between the occurrence of MS and exclusive breast feeding, season of birth, and smoking. However, the association was not statistically significant after adjustment for other covariates.Conclusion: The risk of MS is significantly lower in male gender, obese/overweight, and old people. Furthermore, non-smoking, non-exclusive breast-feeding, and born in autumn may increase the risk of MS but need further investigation. However, long-term large prospective cohort studies are needed to investigate the true effect of the potential risk factors on MS. Keywords: Multiple sclerosis, Risk factors, Case-control study, Iran

  8. Human factors survey of advanced instrumentation and controls

    International Nuclear Information System (INIS)

    The nuclear power industry has used analog instrumentation and controls (I and C) in their control rooms and technical support centers since the first nuclear power plant went on-line in the late 1950's. Even today the industry, as a whole, has been slow to implement advanced/digital I and C. The utilization of digital I and C appears, however, to be the wave of the future because most of the analog components and systems are becoming obsolete and no longer available. These advanced systems will also probably be utilized in the life extension of nuclear plants. It has been demonstrated in other industries that digital I and C provides almost error-free performance that is three-to-four orders of magnitude better than analog components performing the same function. With the increase in sophistication in the operation of modern nuclear power plants that is needed to handle the multiple (and sometimes conflicting) goals of efficiency, reliability, economic operation, and safety, the nuclear industry will be driven to the use of advanced I and C. Oak Ridge National Laboratory (ORNL) is currently performing a research project for the Nuclear Regulatory Commission's (NRC) Office of Nuclear Regulatory Research. The purpose of the project is to provide the technical basis for the development of regulatory criteria to evaluate the safety implications of human factors associated with advanced I and C in nuclear power plants. During the first part of this project a survey of the US and Canadian utilities and vendors was conducted. The survey was oriented towards determining the human factors issues related to the current, planned, and potential future uses of digital systems in control rooms and technical support centers. The human factors issues were prioritized in regards to their importance by representatives from both ORNL and NRC

  9. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    KAUST Repository

    Prest, Emmanuelle I.

    2016-02-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  10. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges

    Science.gov (United States)

    Prest, Emmanuelle I.; Hammes, Frederik; van Loosdrecht, Mark C. M.; Vrouwenvelder, Johannes S.

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  11. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges.

    Science.gov (United States)

    Prest, Emmanuelle I; Hammes, Frederik; van Loosdrecht, Mark C M; Vrouwenvelder, Johannes S

    2016-01-01

    Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g., development of opportunistic pathogens), aesthetic (e.g., deterioration of taste, odor, color) or operational (e.g., fouling or biocorrosion of pipes) problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors, such as (i) type and concentration of available organic and inorganic nutrients, (ii) type and concentration of residual disinfectant, (iii) presence of predators, such as protozoa and invertebrates, (iv) environmental conditions, such as water temperature, and (v) spatial location of microorganisms (bulk water, sediment, or biofilm). Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability) in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i) existing knowledge on biological stability controlling factors and (ii) how these factors are affected by drinking water production and distribution conditions. In addition, (iii) the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discussed, how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order

  12. Biological stability of drinking water: controlling factors, methods and challenges

    Directory of Open Access Journals (Sweden)

    Emmanuelle ePrest

    2016-02-01

    Full Text Available Biological stability of drinking water refers to the concept of providing consumers with drinking water of same microbial quality at the tap as produced at the water treatment facility. However, uncontrolled growth of bacteria can occur during distribution in water mains and premise plumbing, and can lead to hygienic (e.g. development of opportunistic pathogens, aesthetic (e.g. deterioration of taste, odour, colour or operational (e.g. fouling or biocorrosion of pipes problems. Drinking water contains diverse microorganisms competing for limited available nutrients for growth. Bacterial growth and interactions are regulated by factors such as (i type and concentration of available organic and inorganic nutrients, (ii type and concentration of residual disinfectant, (iii presence of predators such as protozoa and invertebrates, (iv environmental conditions such as water temperature, and (v spatial location of microorganisms (bulk water, sediment or biofilm. Water treatment and distribution conditions in water mains and premise plumbing affect each of these factors and shape bacterial community characteristics (abundance, composition, viability in distribution systems. Improved understanding of bacterial interactions in distribution systems and of environmental conditions impact is needed for better control of bacterial communities during drinking water production and distribution. This article reviews (i existing knowledge on biological stability controlling factors and (ii how these factors are affected by drinking water production and distribution conditions. In addition, (iii the concept of biological stability is discussed in light of experience with well-established and new analytical methods, enabling high throughput analysis and in-depth characterization of bacterial communities in drinking water. We discuss how knowledge gained from novel techniques will improve design and monitoring of water treatment and distribution systems in order to

  13. Irradiated microstructures of magnesium aluminate spinel and their controlling factors

    International Nuclear Information System (INIS)

    This paper reviews out recent progress in study on the strong resistance of magnesium aluminate spinel to void swelling during irradiation, along with the related characteristic features of its radiation damage. Comparative experimental results on irradiated microstructures and mechanical properties in magnesium aluminate spinel and alpha-alumina are shown in terms of controlling factors of radiation resistance of the former crystal. It is experimentally shown that structural vacancies due to non-stoichiometry provide effective recombination sites for displaced cations to suppress the formation of interstitial loops. Decreased formation of interstitial loops enhances the further recombination of interstitials and vacancies and thereby the formation of voids

  14. Patient factors and glycaemic control--associations and explanatory power

    DEFF Research Database (Denmark)

    Rogvi, S; Tapager, I; Almdal, T P;

    2012-01-01

    associated with older age, higher education, higher patient activation, lower diabetes-related emotional distress, better diet and exercise behaviours, lower body mass index, shorter duration of disease and knowledge of HbA(1c) targets (P ...AIMS: To investigate the association between glycaemic control and patient socio-demographics, activation level, diabetes-related distress, assessment of care, knowledge of target HbA(1c), and self-management behaviours, and to determine to what extent these factors explain the variance in HbA(1c...... and behaviour, specific treatment modalities and glycaemic control. Knowledge of treatment goals, achieving patient activation in coping with diabetes, and lowering disease-related emotional stress are important patient education goals. However, the large unexplained component of HbA(1c) variance highlights...

  15. Human factors in remote control engineering development activities

    International Nuclear Information System (INIS)

    Human factors engineering, which is an integral part of the advanced remote control development activities at the Oak Ridge National Laboratory, is described. First, work at the Remote Systems Development Facility (RSDF) has shown that operators can perform a wide variety of tasks, some of which were not specifically designed for remote systems, with a dextrous electronic force-reflecting servomanipulator and good television remote viewing capabilities. Second, the data collected during mock-up remote maintenance experiments at the RSDF have been analyzed to provide guidelines for the design of human interfaces with an integrated advanced remote maintenance system currently under development. Guidelines have been provided for task allocation between operators, remote viewing systems, and operator controls. 6 references, 5 figures, 2 tables

  16. Three controllable factors of steady operation of EGSB reactor

    Institute of Scientific and Technical Information of China (English)

    LI Hui-li; LU Bing-nan; LI Fang

    2008-01-01

    The bench- scale EGSB (expanded granular sludge bed) reactor was operated to study the effect of sludge loading rate, pH value and nutrient element on the operation of the EGSB reactor and the control rule of these factors. Continuous flow was used to treat synthetic wastewater containing dextrose and beer, and the temperature of reactor was controlled at mesophiles temperature (33 ℃). The experimental results demonstrated trolled by adding sodium bicarbonate, the proper additive quantity was 1000-1200 mg/L; the additive quantity wastewater with 400-5000 mg/L COD concentration. The COD removal efficiency was over 85%. The operation of the EGSB reactor was steady and the EGSB reactor had strong anti-shock load ability.

  17. Understanding disease control: influence of epidemiological and economic factors.

    Directory of Open Access Journals (Sweden)

    Katarzyna Oleś

    Full Text Available We present a model of disease transmission on a regular and small world network and compare different control options. Comparison is based on a total cost of epidemic, including cost of palliative treatment of ill individuals and preventive cost aimed at vaccination or culling of susceptible individuals. Disease is characterized by pre-symptomatic phase, which makes detection and control difficult. Three general strategies emerge: global preventive treatment, local treatment within a neighborhood of certain size and only palliative treatment with no prevention. While the choice between the strategies depends on a relative cost of palliative and preventive treatment, the details of the local strategy and, in particular, the size of the optimal treatment neighborhood depend on the epidemiological factors. The required extent of prevention is proportional to the size of the infection neighborhood, but depends on time till detection and time till treatment in a non-nonlinear (power law. The optimal size of control neighborhood is also highly sensitive to the relative cost, particularly for inefficient detection and control application. These results have important consequences for design of prevention strategies aiming at emerging diseases for which parameters are not nessecerly known in advance.

  18. Predictive factors of seizure control in childhood onset epilepsy

    Directory of Open Access Journals (Sweden)

    Eli Shahar

    2008-01-01

    Full Text Available Background: Prediction of the long-term outcomes of childhood-onset epilepsy remains crucial for the future well-being of the affected children and their families and for planning proper therapeutic and educational programs. Objective: To identify and analyze the early predictive factors of seizure control in childhood-onset epilepsies referred at the age of 1 month up to the age of 18 years to the Epilepsy Service at the Meyer Children Hospital, Rambam Medical Center, Haifa, Israel. Materials and Methods: In this study, children who were newly diagnosed with epileptic disorders and treated with antiepileptic drug therapy - who became either completely controlled for at least twelve months or those remaining intractable - were included. Partially responding children were excluded from the analysis. The etiology was segregated into either symptomatic or nonsymptomatic epilepsy, referred to as idiopathic epilepsy. Results: Overall, 74 children (mean age: 4.27 ± 4 years at the first seizure were found eligible for analysis followed for a mean period of 4.5 years. Fifty-three (72% children became seizure-free for a mean period of 20 months on antiepileptic drug (AED therapy and 21 (28% remained uncontrolled. Sixty out of 74 children (81% had idiopathic epilepsy and 14 (19% had symptomatic epilepsy. In those with idiopathic epilepsy, 46 (77% children gained complete seizure control in comparison to 7 out of 14 (50% children in the symptomatic group ( P < 0.01. Thirty-nine out of 47 (83% children who had normal cognition became seizure-free, and 14 (52% out of 27 mentally retarded children also became seizure-free ( P < 0.01. The outcome of seizure control was not affected by age at onset and seizure type itself during the presentation. Conclusion: The present study reveals that the single most predictive factor of a favorable seizure control is preserved cognitive function in accordance with idiopathic epilepsy. However, a fairly high number of

  19. Factors controlling phosphorus release from sediments in coastal archipelago areas.

    Science.gov (United States)

    Puttonen, Irma; Kohonen, Tuula; Mattila, Johanna

    2016-07-15

    In coastal archipelago areas of the northern Baltic Sea, significantly higher phosphate concentrations (6.0±4.5μmol/l, mean±SD) were measured in water samples close to the sediment surface compared with those from 1m above the seafloor (1.6±2.0μmol/l). The results indicated notable phosphate release from sediments under the bottom water oxygen concentrations of up to 250μmol/l, especially in areas that had experienced recent temporal fluctuation between oxic and hypoxic/anoxic conditions. No single factor alone was found to control the elevated PO4-P concentrations in the near-bottom water. In addition to the oxygen in the water, the contents of potentially mobile phosphorus fractions, grain-size, the organic content at the sediment surface, and the water depth were all important factors controlling the internal loading of phosphorus. The complexity of this process needs to be accounted for in assessments of the internal loading of phosphorus and in potential mitigation plans. PMID:27184132

  20. Phase detector for three-phase power factor controller

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1984-01-01

    A phase detector for the three phase power factor controller (PFC) is described. The phase detector for each phase includes an operational amplifier which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier. this feedback preferably comprises a resistor connected between the output and input of the operational amplifier. The novelty of the invention resides in providing positive feedback such that switching of the operational amplifier is synchronized with switching of the voltage across the thyristor. The invention provides a solution to problems associated with high common mode voltage and enables use of lower cost components than would be required by other approaches.

  1. Study of factors controlling organic pollution in Lake Kiba

    International Nuclear Information System (INIS)

    Lake Kiba is located in Ishikawa Prefecture and has been facing to high COD value, a simple indicator of organic pollution, of lake water. This study analyzed organic matter content in a sediment core with time scale and discussed factors controlling COD value. Sedimentation rate estimated from depth profile of 210Pbex is divided into three periods such as present-1989, 1989-1959 and 1959-past. TOC flux at the present is five times higher than that of 1959. The TOC/TN molar ratio decreased from 15.7 to 12.8. These results suggest that accumulation of total organic matter increases but the contribution of terrestrial organic matter and phytoplankton relatively varies with time. (author)

  2. Factors controlling the structures of magma chambers in basaltic volcanoes

    Science.gov (United States)

    Wilson, L.; Head, James W.

    1991-01-01

    The depths, vertical extents, and lateral extents of magma chambers and their formation are discussed. The depth to the center of a magma chamber is most probably determined by the density structure of the lithosphere; this process is explained. It is commonly assumed that magma chambers grow until the stress on the roof, floor, and side-wall boundaries exceed the strength of the wall rocks. Attempts to grow further lead to dike propagation events which reduce the stresses below the critical values of rock failure. The tensile or compressive failure of the walls is discussed with respect to magma migration. The later growth of magma chambers is accomplished by lateral dike injection into the country rocks. The factors controlling the patterns of growth and cooling of such dikes are briefly mentioned.

  3. Transcription factor PIF4 controls the thermosensory activation of flowering

    KAUST Repository

    Kumar, S. Vinod

    2012-03-21

    Plant growth and development are strongly affected by small differences in temperature. Current climate change has already altered global plant phenology and distribution, and projected increases in temperature pose a significant challenge to agriculture. Despite the important role of temperature on plant development, the underlying pathways are unknown. It has previously been shown that thermal acceleration of flowering is dependent on the florigen, FLOWERING LOCUS T (FT). How this occurs is, however, not understood, because the major pathway known to upregulate FT, the photoperiod pathway, is not required for thermal acceleration of flowering. Here we demonstrate a direct mechanism by which increasing temperature causes the bHLH transcription factor PHYTOCHROME INTERACTING FACTOR4 (PIF4) to activate FT. Our findings provide a new understanding of how plants control their timing of reproduction in response to temperature. Flowering time is an important trait in crops as well as affecting the life cycles of pollinator species. A molecular understanding of how temperature affects flowering will be important for mitigating the effects of climate change. © 2012 Macmillan Publishers Limited. All rights reserved.

  4. Biodiversity mediates top-down control in eelgrass ecosystems: a global comparative-experimental approach.

    Science.gov (United States)

    Duffy, J Emmett; Reynolds, Pamela L; Boström, Christoffer; Coyer, James A; Cusson, Mathieu; Donadi, Serena; Douglass, James G; Eklöf, Johan S; Engelen, Aschwin H; Eriksson, Britas Klemens; Fredriksen, Stein; Gamfeldt, Lars; Gustafsson, Camilla; Hoarau, Galice; Hori, Masakazu; Hovel, Kevin; Iken, Katrin; Lefcheck, Jonathan S; Moksnes, Per-Olav; Nakaoka, Masahiro; O'Connor, Mary I; Olsen, Jeanine L; Richardson, J Paul; Ruesink, Jennifer L; Sotka, Erik E; Thormar, Jonas; Whalen, Matthew A; Stachowicz, John J

    2015-07-01

    Nutrient pollution and reduced grazing each can stimulate algal blooms as shown by numerous experiments. But because experiments rarely incorporate natural variation in environmental factors and biodiversity, conditions determining the relative strength of bottom-up and top-down forcing remain unresolved. We factorially added nutrients and reduced grazing at 15 sites across the range of the marine foundation species eelgrass (Zostera marina) to quantify how top-down and bottom-up control interact with natural gradients in biodiversity and environmental forcing. Experiments confirmed modest top-down control of algae, whereas fertilisation had no general effect. Unexpectedly, grazer and algal biomass were better predicted by cross-site variation in grazer and eelgrass diversity than by global environmental gradients. Moreover, these large-scale patterns corresponded strikingly with prior small-scale experiments. Our results link global and local evidence that biodiversity and top-down control strongly influence functioning of threatened seagrass ecosystems, and suggest that biodiversity is comparably important to global change stressors. PMID:25983129

  5. Risk factors in pediatric asthmatic patients. Cases and control studies.

    Directory of Open Access Journals (Sweden)

    Rafael Alejandro Gómez Baute

    2003-04-01

    Full Text Available Background: Asthma constitutes the first disease among chronic diseases in children. The morbid-mortality promoted to continue being elevated in spite of the new therapies. For this reason it is a disease with high priority for investigation in pediatric ages. Method: A control and case group study was carried out. The samples was composed by 72 asthmatic children from three General Comprehensive doctor offices from Palmira health area located in Cienfuegos Province, Cuba; and a control group of 72 children apparently healthy from the same population. A questionnaire with the different risk variables was elaborated. Odds ratio technique was used to estimate the risk. Results: low weight at birth, family history of asthma, brochiolitis antecedent and the excessive usage of antibiotics in children under 1 year old were the main risks found. Conclusions: It is conclusive that the exposure to home allergen plus a genetic favorable factor, the prematurity, and brochiolitis constituted the most outstanding elements to suffer from asthma in the population studied.

  6. Factors Controlling Nitrogen Fluxes in Groundwater in Agricultural Areas

    Science.gov (United States)

    Liao, L.; Green, C. T.; Bekins, B. A.; Bohlke, J. K.

    2010-12-01

    Predictions of effects of land use changes on water quality require identification of the relative importance of geochemical and hydrologic factors. To understand the factors controlling the transport of nitrogen in groundwater, vertical fluxes of water and solutes were estimated for 13 aquifers in agricultural areas located in California, Iowa, Maryland, Minnesota, Mississippi, Nebraska, North Carolina, Texas, and Wisconsin. The aquifers are overlain by unsaturated zones with thicknesses ranging from 2.5 to 100 m. Precipitation ranges from 19 to 132 cm/yr and irrigation ranges from 0 to 120 cm/yr. Main crop types include corn, soybeans, forage, wheat, and cotton. A 1-dimensional mathematical model was developed to estimate vertical N transport in response to N inputs on the land surface from chemical fertilizer, manure and atmospheric deposition. Simulated vertical profiles of O2, NO3-, N2 from denitrification, Cl- and atmospheric age tracers were matched to observations by adjusting parameters for recharge rate, unsaturated zone travel time, N leaching ratio (defined as leaching fraction of N reaching water table of N input at land surface), Cl- leaching ratio, O2 reduction rate and denitrification rate. Results indicated that vertical NO3 fluxes below the water table were affected by both geochemical and physical factors. High vertical NO3 fluxes below the water table are associated with high N input at the land surface. Values of Cl- leaching ratios were less than 1 (0.42 to 1) likely as a result of runoff and exported harvested crops. N leaching ratios were lower (0.1 to 0.6), consistent with additional N losses such as denitrification and volatilization. The sites with high leaching ratios for both N and Cl tended to be those with high recharge rates and low ET loss, defined as the fraction of applied water lost to ET. Modeled zero-order denitrification rates in the saturated zone varied within an order of magnitude with a maximum rate of 1.6 mg

  7. Spatial and temporal variations and controlling factors of sediment accumulation in the Yangtze River estuary and its adjacent sea area in the Holocene, especially in the Early Holocene

    Science.gov (United States)

    Feng, Zhibing; Liu, Baohua; Zhao, Yuexia; Li, Xishuang; Jiang, Li; Si, Shaokun

    2016-08-01

    The sub-bottom and collected borehole data provide insight into the transport and accumulation processes of the Yangtze-derived sediment in the study area since ~11 kyr BP. Five seismic units were identified according to six major acoustic surfaces. The sedimentary strata consist of fluvial, estuarine and deltaic systems from the bottom up, characterized by two different trends in sediment accumulation rates, i.e., low-high-low, and high-low-high. On the inner shelf of the East China Sea, the terrain with trough and ridge was formed by the Early Holocene transgression strata (formed in ~10 to 12 kyr BP) scoured by the later rectilinear tidal current due to postglacial sea-level transgression, and the sharply protruding seismic units are interpreted to be bedrocks outcropping on the seafloor. An analysis of the sedimentary characteristics in the boreholes and such factors as difference in accumulation rates, and tectonic subsidence led us to conclude that the paleo-coastline was located not far away from and to the east of Core ZK09 at ~9 kyr BP, and the southern bank of the Yangtze River estuary was located to the south of Core ZK09. At ~9 kyr, large volume of sediments was deposited in the northern isles of the Zhoushan archipelago and their adjacent bedrocks, forming a barrier effect on later sediment transport. During 7.5-8 kyr BP, the Yangtze-derived sediments were transported eastwards along the southern bank of the Yangtze River and the barrier due to the influence of the paleo-coastal current from the north, the direction of the Yangtze-derived sediment transport was split on the northeast of the Zhoushan archipelago, and the sediments covered the terrain with trough and ridge. During the high sea level period (7 kyr BP-present), the eastward migration of paleo-coastline had resulted in the increase in accumulation rate. We also conclude that the sharp increase in accumulation rate near the Yangtze River estuary after ~2 kyr BP was not primarily caused by

  8. Ex-post evaluation of local energy efficiency and demand-side management operations - State of the art, bottom-up methods, applied examples and approach for the development of an evaluation practical culture

    International Nuclear Information System (INIS)

    Energy end-use Efficiency (EE) is a priority for energy policies to face resources exhaustion and to reduce pollutant emissions. At the same time, in France, local level is increasingly involved into the implementation of EE activities, whose frame is changing (energy market liberalization, new policy instruments). Needs for ex-post evaluation of the local EE activities are thus increasing, for regulation requirements and to support a necessary change of scale. Our thesis focuses on the original issue of the ex-post evaluation of local EE operations in France. The state of the art, through the analysis of the American and European experiences and of the reference guidebooks, gives a substantial methodological material and emphasises the key evaluation issues. Concurrently, local EE operations in France are characterized by an analysis of their environment and a work on their segmentation criteria. The combination of these criteria with the key evaluation issues provides an analysis framework used as the basis for the composition of evaluation methods. This also highlights the specific evaluation needs for local operations. A methodology is then developed to complete and adapt the existing material to design evaluation methods for local operations, so that stakeholders can easily appropriate. Evaluation results thus feed a know-how building process with experience feedback. These methods are to meet two main goals: to determine the operation results, and to detect the success/failure factors. The methodology was validated on concrete cases, where these objectives were reached. (author)

  9. Hydrologic factors controlling groundwater salinity in northwestern coastal zone, Egypt

    Indian Academy of Sciences (India)

    Nahla A Morad; M H Masoud; S M Abdel Moghith

    2014-10-01

    The aim of this article is to assess the main factors influencing salinity of groundwater in the coastal area between El Dabaa and Sidi Barani, Egypt. The types and ages of the main aquifers in this area are the fractured limestone of Middle Miocene, the calcareous sandstone of Pliocene and the Oolitic Limestone of Pleistocene age. The aquifers in the area are recharged by seasonal rainfall of the order of 150 mm/year. The relationship of groundwater salinity against the absolute water level, the well drilling depth, and the ability of aquifer to recharge has been discussed in the present work. The ability of aquifer to locally recharge by direct rainfall is a measure of the vertical permeability due to lithological and structural factors that control groundwater salinity in the investigated aquifers. On the other hand, the fracturing system as well as the attitude of the surface water divide has a prime role in changing both the mode of occurrence and the salinity of groundwater in the area. Directly to the west of Matrouh, where the coastal plain is the narrowest, and east of Barrani, where the coastal plain is the widest, are good examples of this concept, where the water salinity attains its maximum and minimum limits respectively. Accordingly, well drilling in the Miocene aquifer, in the area between El Negila and Barrani to get groundwater of salinities less than 5000 mg/l is recommended in this area, at flow rate less than 10m3/hr/well. In other words, one can expect that the brackish water is probably found where the surface water divide is far from the shore line, where the Wadi fill deposits dominate (Quaternary aquifer), acting as a possible water salinity by direct rainfall and runoff.

  10. Hydrologic factors controlling groundwater salinity in northwestern coastal zone, Egypt

    Science.gov (United States)

    Morad, Nahla A.; Masoud, M. H.; Moghith, S. M. Abdel

    2014-10-01

    The aim of this article is to assess the main factors influencing salinity of groundwater in the coastal area between El Dabaa and Sidi Barani, Egypt. The types and ages of the main aquifers in this area are the fractured limestone of Middle Miocene, the calcareous sandstone of Pliocene and the Oolitic Limestone of Pleistocene age. The aquifers in the area are recharged by seasonal rainfall of the order of 150 mm/year. The relationship of groundwater salinity against the absolute water level, the well drilling depth, and the ability of aquifer to recharge has been discussed in the present work. The ability of aquifer to locally recharge by direct rainfall is a measure of the vertical permeability due to lithological and structural factors that control groundwater salinity in the investigated aquifers. On the other hand, the fracturing system as well as the attitude of the surface water divide has a prime role in changing both the mode of occurrence and the salinity of groundwater in the area. Directly to the west of Matrouh, where the coastal plain is the narrowest, and east of Barrani, where the coastal plain is the widest, are good examples of this concept, where the water salinity attains its maximum and minimum limits respectively. Accordingly, well drilling in the Miocene aquifer, in the area between El Negila and Barrani to get groundwater of salinities less than 5000 mg/l is recommended in this area, at flow rate less than 10 m3/hr/well. In other words, one can expect that the brackish water is probably found where the surface water divide is far from the shore line, where the Wadi fill deposits dominate (Quaternary aquifer), acting as a possible water salinity by direct rainfall and runoff.

  11. Factors controlling hydrogen cracking during cladding of nuclear vessel steels

    International Nuclear Information System (INIS)

    During cladding of low alloy steels in nuclear pressure vessels for corrosion resistance, a potential problem exists of underclad hydrogen cracking. Research was undertaken to gain a better insight into the factors controlling underclad hydrogen cracking during cladding A508 Cl 3 nuclear vessel steels and to ensure the continued development of safe welding procedures in this critical application. The project was divided into three experimental phases. Phase I studied the potential and deposit hydrogen levels in Type 309 austenitic stainless steel and Ni alloy consumables and weld metals. Phase II incorporated implant testing of the A508 Cl 3 base material. A large test panel was fabricated in Phase III to approach the conditions of restraint and heat sink that are present in the pressure vessel cladding operation, but not necessarily those of the most critical components, such as nozzles where the cylindrical geometry may increase the overall restraint. The A508 Cl 3 test material was electron beam welded into the center of the test block which was then submerged arc-strip clad using very severe welding conditions in an attempt to generate underclad hydrogen cracks. It was found that for the shielded metal-arc welding (SMAW) and submerged arc welding (SAW) processes, deposit hydrogen levels were primarily controlled by flux moisture content. With single layer deposition, the implant test did not show evidence of the influence of segregation on cold cracking. All SMAW implant tests, without preheat and regardless of consumable, gave lower critical stress thresholds below about 51 ksi. A preheat of 150 deg.C increased this threshold to 80 ksi with Type 306 consumables. Even under welding conditions favorable for cracking, underclad hydrogen cracks could not be developed in a large-scale simulation of a cladding operation, indicating that very high total system restraint is needed to induce cracking

  12. Factors Influencing Compliance with Infection Control Practice in Japanese Dentists

    Directory of Open Access Journals (Sweden)

    A Tada

    2014-01-01

    Full Text Available Background: In recent years, dentists have more opportunity of treating patients infected with blood-borne pathogens. Although compliance with infection control practice (ICP in dental practice is required, it is not still sufficiently spread in Japan.Objective: To identify factors associated with compliance with ICPs in the population of Japanese dentists.Methods: In a questionnaire-based cross-sectional study in 2009, 2134 dentists in Aichi prefecture, Japan, were surveyed. They were asked for their demographic characteristics, willingness to treat HIV/AIDS patients, and knowledge about universal/standard precautions and ICP.Results: Many ICP items had significant association with age, specialty for oral surgery, number of patients treated per day, willingness to treat HIV/AIDS patients and knowledge about the universal/standard precautions. In logistic regression model, knowledge about the precautions had significant associations with all ICP items. Among participants with disadvantageous characteristic group for ICP (ie, age ≥50 years, being general dentist, and treating ≤35 patients/day, knowledge about the universal/standard precautions had greater impact on exchanging handpiece for each patient and installing extra-oral vacuum in those with age of ≥50 years than in those who visited ≤35 patient per day.Conclusion: Knowledge about the meaning of universal/standard precautions is the most significant predictor of compliance with ICPs among Japanese dentists.

  13. Ex-post evaluation of local energy efficiency and demand-side management operations - State of the art, bottom-up methods, applied examples and approach for the development of an evaluation practical culture; L'evaluation ex-post des operations locales de maitrise de la demande en energie - Etat de l'art, methodes bottom-up, exemples appliques et approche du developpement d'une culture pratique de l'evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Broc, J.S

    2006-12-15

    Energy end-use Efficiency (EE) is a priority for energy policies to face resources exhaustion and to reduce pollutant emissions. At the same time, in France, local level is increasingly involved into the implementation of EE activities, whose frame is changing (energy market liberalization, new policy instruments). Needs for ex-post evaluation of the local EE activities are thus increasing, for regulation requirements and to support a necessary change of scale. Our thesis focuses on the original issue of the ex-post evaluation of local EE operations in France. The state of the art, through the analysis of the American and European experiences and of the reference guidebooks, gives a substantial methodological material and emphasises the key evaluation issues. Concurrently, local EE operations in France are characterized by an analysis of their environment and a work on their segmentation criteria. The combination of these criteria with the key evaluation issues provides an analysis framework used as the basis for the composition of evaluation methods. This also highlights the specific evaluation needs for local operations. A methodology is then developed to complete and adapt the existing material to design evaluation methods for local operations, so that stakeholders can easily appropriate. Evaluation results thus feed a know-how building process with experience feedback. These methods are to meet two main goals: to determine the operation results, and to detect the success/failure factors. The methodology was validated on concrete cases, where these objectives were reached. (author)

  14. Viral control of bacterial biodiversity - Evidence from a nutrient enriched mesocosm experiment

    DEFF Research Database (Denmark)

    Sandaa, R.-A.; Gómez-Consarnau, L.; Pinhassi, J.;

    2009-01-01

    We demonstrate here results showing that bottom-up and top-down control mechanisms can operate simultaneously and in concert in marine microbial food webs, controlling prokaryote diversity by a combination of viral lysis and substrate limitation. Models in microbial ecology predict that a shift in....... As predicted, the total number of viral populations was the same in all treatments, while the composition of the viral community varied. Our results support the theoretical prediction that there is one control mechanism for the number of niches for coexisting virus-host pairs (top-down control), and...... another mechanism that controls which virus-host pairs occupy these niches (bottom-up control)....

  15. Control factors of partial nitritation for landfill leachate treatment

    Institute of Scientific and Technical Information of China (English)

    LIANG Zhu; LIU Jun-xin

    2007-01-01

    Anaerobic ammonium oxidation (ANAMMOX) technology has potential technical superiority and economical efficiency for the nitrogen removal from landfill leachate, which contains high-strength ammonium nitrogen (NH4+-N) and refractory organics. To complete the ANAMMOX process, a preceding partial nitritation step to produce the appropriate ratio of nitrite/ammonium is a key stage. The objective of this study was to determine the optimal conditions to acquire constant partial nitritation for landfill leachate treatment, and a bench scale fixed bed bio-film reactor was used in this study to investigate the effects of the running factors on the partial nitritation. The results showed that both the dissolved oxygen (DO) concentration and the ammonium volumetric loading rate (Nv) had effects on the partial nitritation. In the controlling conditions with a temperature of 30±1℃, Nv of 0.2-1.0 kg NH4+-N/(m3·d), and DO concentration of 0.8-2.3 mg/L, the steady partial nitritation was achieved as follows: more than 94% partial nitritation efficiency (nitrite as the main product), 60%-74% NH4+-N removal efficiency, and NO2--N/NH4+-N ratio (concentration ratio) of 1.0-1.4 in the effluent.The impact of temperature was related to Nv at certain DO concentration, and the temperature range of 25-30℃ was suitable for treating high strength ammonium leachate. Ammonium-oxidizing bacteria (AOB) could be acclimated to higher FA (free ammonium) in the range of 122-224 mg/L. According to the denaturing gradient gel electrophoresis analysis result of the bio-film in the reactor, there were 25 kinds of 16S rRNA gene fragments, which indicated that abundant microbial communities existed in the bio-film, although high concentrations of ammonium and FA may inhibit the growth of the nitrite-oxidizing bacteria (NOB) and other microorganisms in the reactor.

  16. The Galactic Center Excess from the Bottom Up

    CERN Document Server

    Izaguirre, Eder; Shuve, Brian

    2014-01-01

    It has recently been shown that dark-matter annihilation to bottom quarks provides a good fit to the galactic-center gamma-ray excess identified in the Fermi-LAT data. In the favored dark matter mass range $m\\sim 30-40$ GeV, achieving the best-fit annihilation rate $\\sigma v \\sim 5\\times 10^{-26}$ cm$^{3}$ s$^{-1}$ with perturbative couplings requires a sub-TeV mediator particle that interacts with both dark matter and bottom quarks. In this paper, we consider the minimal viable scenarios in which a Standard Model singlet mediates s-channel interactions {\\it only} between dark matter and bottom quarks, focusing on axial-vector, vector, and pseudoscalar couplings. Using simulations that include on-shell mediator production, we show that existing sbottom searches currently offer the strongest sensitivity over a large region of the favored parameter space explaining the gamma-ray excess, particularly for axial-vector interactions. The 13 TeV LHC will be even more sensitive; however, it may not be sufficient to f...

  17. A different perspective on architectural design: bottom up participative experiences

    OpenAIRE

    Cimadomo, Guido

    2014-01-01

    The weight of the financial and real estate components in the present crisis, and their impact on millions of people give a renewed importance to the right to housing and the wider right to the city. The paper of architects in planning the city is also changing due to new social relations and the empowerment of citizens, and we have not to forget that scarcity is a great impulse for social and technical innovation, among them architecture. Henry Lefebvre’s “The right to the city” (Lefebvre 19...

  18. Bottom-up approaches for organizing nanoparticles with polymers

    OpenAIRE

    Minelli, Caterina; Vogel, Horst

    2005-01-01

    This thesis describes some of three years'work carried at the Centre Suisse d'Electronique et de Microtechnique (Neuchâtel, Switzerland) under the supervision of Dr. Martha Liley and in collaboration with Prof. Horst Vogel of the Ecole Polytechnique Fédérale of Lausanne (Switzerland). The goal of this work is to contribute to the development of innovative technologies in the treatment of surfaces, for the lateral organization of various materials on the micrometer and nanometer scale. The aim...

  19. Contextualised ICT4D: a Bottom-Up Approach

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Sutinen, Erkki

    2010-01-01

    their own strengths to new levels by designing appropriate technologies with experts of technology and design. The bottomup approach requires a new kind of ICT education at the undergraduate level. An example of the development of a contextualized IT degree program at Tumaini University in Tanzania...

  20. Bottom-Up/Top-Down Leadership: Contradiction or Hidden Phenomenon

    Science.gov (United States)

    Kezar, Adrianna

    2012-01-01

    The study advances higher education leadership and change scholarship by examining a mostly unexplored area--the convergence between grassroots leadership with top-down leadership. The study is framed by two theories: tempered radicals framework and distributed leadership. Three common example of convergence are described as well as strategies for…