Sample records for considerable plant simplification

  1. Fundamentals of the Control of Gas-Turbine Power Plants for Aircraft. Part III Control of Jet Engines. Part 3; Control of Jet Engines

    NASA Technical Reports Server (NTRS)

    Kuehl, H.

    1947-01-01

    The basic principles of the control of TL ongincs are developed on .the basis of a quantitative investigation of the behavior of these behavior under various operating conditions with particular consideration of the simplifications pormissible in each case. Various possible means of control of jet engines are suggested and are illustrated by schematic designs.

  2. Simplification of a light-based model for estimating final internode length in greenhouse cucumber canopies.

    PubMed

    Kahlen, Katrin; Stützel, Hartmut

    2011-10-01

    Light quantity and quality affect internode lengths in cucumber (Cucumis sativus), whereby leaf area and the optical properties of the leaves mainly control light quality within a cucumber plant community. This modelling study aimed at providing a simple, non-destructive method to predict final internode lengths (FILs) using light quantity and leaf area data. Several simplifications of a light quantity and quality sensitive model for estimating FILs in cucumber have been tested. The direct simplifications substitute the term for the red : far-red (R : FR) ratios, by a term for (a) the leaf area index (LAI, m(2) m(-2)) or (b) partial LAI, the cumulative leaf area per m(2) ground, where leaf area per m(2) ground is accumulated from the top of each plant until a number, n, of leaves per plant is reached. The indirect simplifications estimate the input R : FR ratio based on partial leaf area and plant density. In all models, simulated FILs were in line with the measured FILs over various canopy architectures and light conditions, but the prediction quality varied. The indirect simplification based on leaf area of ten leaves revealed the best fit with measured data. Its prediction quality was even higher than of the original model. This study showed that for vertically trained cucumber plants, leaf area data can substitute local light quality data for estimating FIL data. In unstressed canopies, leaf area over the upper ten ranks seems to represent the feedback of the growing architecture on internode elongation with respect to light quality. This highlights the role of this domain of leaves as the primary source for the specific R : FR signal controlling the final length of an internode and could therefore guide future research on up-scaling local processes to the crop level.

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

    Jose Reyes

    In recent years it has been recognized that the application of passive safety systems (i.e., those whose operation takes advantage of natural forces such as convection and gravity), can contribute to simplification and potentially to improved economics of new nuclear power plant designs. In 1991 the IAEA Conference on ''The Safety of Nuclear Power: Strategy for the Future'' noted that for new plants the use of passive safety features is a desirable method of achieving simplification and increasing the reliability of the performance of essential safety functions, and should be used wherever appropriate''.

  4. Biodiversity and ecosystem stability in a decade-long grassland experiment.

    PubMed

    Tilman, David; Reich, Peter B; Knops, Johannes M H

    2006-06-01

    Human-driven ecosystem simplification has highlighted questions about how the number of species in an ecosystem influences its functioning. Although biodiversity is now known to affect ecosystem productivity, its effects on stability are debated. Here we present a long-term experimental field test of the diversity-stability hypothesis. During a decade of data collection in an experiment that directly controlled the number of perennial prairie species, growing-season climate varied considerably, causing year-to-year variation in abundances of plant species and in ecosystem productivity. We found that greater numbers of plant species led to greater temporal stability of ecosystem annual aboveground plant production. In particular, the decadal temporal stability of the ecosystem, whether measured with intervals of two, five or ten years, was significantly greater at higher plant diversity and tended to increase as plots matured. Ecosystem stability was also positively dependent on root mass, which is a measure of perenniating biomass. Temporal stability of the ecosystem increased with diversity, despite a lower temporal stability of individual species, because of both portfolio (statistical averaging) and overyielding effects. However, we found no evidence of a covariance effect. Our results indicate that the reliable, efficient and sustainable supply of some foods (for example, livestock fodder), biofuels and ecosystem services can be enhanced by the use of biodiversity.

  5. White Cliffs: Operating Experience

    NASA Technical Reports Server (NTRS)

    Kaneff, S.

    1984-01-01

    The fourteen dish white cliffs solar power station area is remote and subject to extreme environmental conditions, solution of the associated problems required careful and thoughtful attention and the application of resources. Notwithstanding the wide range and harshness of conditions, the difficulties caused by remoteness and the lack of a technological base and the need for relatively rapid demonstration of success, the project has had a very positive outcome. Qualitative and quantitative information and lessons are now available to enable considerable simplifications to be made for a new system, reducing both hardware and operation and maintenance costs. Experience and lessons are presented, particularly in relation to: system performance in various environmental conditions; design philosophies for collectors, the array, control systems, engine and plant; operation and maintenance strategies and cost reducing possibilities. Experience so far gives encouragement for the future of such paraboloidal dish systems in appropriate areas.

  6. Reauthorizing the Higher Education Act.

    ERIC Educational Resources Information Center

    Lee, John B.

    1983-01-01

    Reviews the process of reauthorizing the Higher Education Act for postsecondary education, beginning with hearings and program reviews. Discusses issues such as political considerations, program simplification, awarding excellence, and availability of information. Pressure groups and budget factors also influence the outcome of the legislative…

  7. Relating the Content and Confidence of Recognition Judgments

    ERIC Educational Resources Information Center

    Selmeczy, Diana; Dobbins, Ian G.

    2014-01-01

    The Remember/Know procedure, developed by Tulving (1985) to capture the distinction between the conscious correlates of episodic and semantic retrieval, has spawned considerable research and debate. However, only a handful of reports have examined the recognition content beyond this dichotomous simplification. To address this, we collected…

  8. Pressure and temperature fields associated with aero-optics tests. [transonic wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Raman, K. R.

    1980-01-01

    The experimental investigation carried out in a 6 x 6 ft wind tunnel on four model configurations in the aero-optics series of tests are described. The data obtained on the random pressures (static and total pressures) and total temperatures are presented. In addition, the data for static pressure fluctuations on the Coelostat turret model are presented. The measurements indicate that the random pressures and temperature are negligible compared to their own mean (or steady state) values for the four models considered, thus allowing considerable simplification in the calculations to obtain the statistical properties of the density field. In the case of the Coelostat model tests these simplifications cannot be assumed a priori and require further investigation.

  9. Evaluation of engineering foods for Controlled Ecological Life Support Systems (CELSS)

    NASA Technical Reports Server (NTRS)

    Karel, M.

    1982-01-01

    The feasibility of developing acceptable and reliable engineered foods for use in controlled ecological support systems (CELSS) was evaluated. Food resupply and regeneration are calculated, flow charts of food processes in a multipurpose food pilot plant are presented, and equipment for a multipurpose food pilot plant and potential simplification of processes are discussed. Food-waste treatment and water usage in food processing and preparation are also considered.

  10. End region and current consolidation effects upon the performance of an MHD channel for the ETF conceptual design

    NASA Technical Reports Server (NTRS)

    Wang, S. Y.; Smith, J. M.

    1981-01-01

    The effects of MHD channel end regions on the overall power generation were considered. The peak plant thermodynamic efficiency was found to be slightly lower than for the active region (41%). The channel operating point for the peak efficiency was shifted to the supersonic mode (Mach No., M sub c approx. 1.1) rather than the previous subsonic operation (M sub c approx. 0.9). The sensitivity of the channel performance to the B-field, diffuser recovery coefficient, channel load parameter, Mach number, and combustor pressure is also discussed. In addition, methods for operating the channel in a constant-current mode are investigated. This mode is highly desirable from the standpoint of simplifying the current and voltage consolidation for the inverter system. This simplification could result in significant savings in the cost of the equipment. The initial results indicate that this simplification is possible, even under a strict Hall field constraint, with resonable plant thermodynamic efficiency (40.5%).

  11. Can You Tell the Density of the Watermelon from This Photograph?

    ERIC Educational Resources Information Center

    Foong, See Kit; Lim, Chim Chai

    2010-01-01

    Based on a photograph, the density of a watermelon floating in a pail of water is estimated with different levels of simplification--with and without consideration of refraction and three-dimensional effects. The watermelon was approximated as a sphere. The results of the theoretical estimations were verified experimentally. (Contains 6 figures.)

  12. Evaluation of engineering foods for closed Ecological Life Support System (CELSS)

    NASA Technical Reports Server (NTRS)

    Karel, M.

    1982-01-01

    A nutritionally adequate and acceptable diet was evaluated and developed. A design for a multipurpose food plant is discussed. The types and amounts of foods needed to be regenerated in a partially closed ecological life support system (PCELSS) were proposed. All steps of food processes to be utilized in the multipurpose food plant of PCELSS were also considered. Equipment specifications, simplification of the proposed processes, and food waste treatment were analyzed.

  13. Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee

    PubMed Central

    Renauld, Miles; Hutchinson, Alena; Loeb, Gregory; Poveda, Katja; Connelly, Heather

    2016-01-01

    Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources. PMID:26943127

  14. Landscape Simplification Constrains Adult Size in a Native Ground-Nesting Bee.

    PubMed

    Renauld, Miles; Hutchinson, Alena; Loeb, Gregory; Poveda, Katja; Connelly, Heather

    2016-01-01

    Bees provide critical pollination services to 87% of angiosperm plants; however, the reliability of these services may become threatened as bee populations decline. Agricultural intensification, resulting in the simplification of environments at the landscape scale, greatly changes the quality and quantity of resources available for female bees to provision their offspring. These changes may alter or constrain the tradeoffs in maternal investment allocation between offspring size, number and sex required to maximize fitness. Here we investigate the relationship between landscape scale agricultural intensification and the size and number of individuals within a wild ground nesting bee species, Andrena nasonii. We show that agricultural intensification at the landscape scale was associated with a reduction in the average size of field collected A. nasonii adults in highly agricultural landscapes but not with the number of individuals collected. Small females carried significantly smaller (40%) pollen loads than large females, which is likely to have consequences for subsequent offspring production and fitness. Thus, landscape simplification is likely to constrain allocation of resources to offspring through a reduction in the overall quantity, quality and distribution of resources.

  15. A Manual on Production Improvement in a Rehabilitation Workshop. Reprint No. 17.

    ERIC Educational Resources Information Center

    Caddick, James W.

    This manual for supervisors of rehabilitation workshops or plants focuses on knowledge, techniques, and application of work simplification and production standards. Four chapters providing introductory material discuss common goals of rehabilitation and production and human factors. The first of seven chapters (chapter 5) on work simplification…

  16. Structure of a viscoplastic theory

    NASA Technical Reports Server (NTRS)

    Freed, Alan D.

    1988-01-01

    The general structure of a viscoplastic theory is developed from physical and thermodynamical considerations. The flow equation is of classical form. The dynamic recovery approach is shown to be superior to the hardening function approach for incorporating nonlinear strain hardening into the material response through the evolutionary equation for back stress. A novel approach for introducing isotropic strain hardening into the theory is presented, which results in a useful simplification. In particular, the limiting stress for the kinematic saturation of state (not the drag stress) is the chosen scalar-valued state variable. The resulting simplification is that there is no coupling between dynamic and thermal recovery terms in each evolutionary equation. The derived theory of viscoplasticity has the structure of a two-surface plasticity theory when the response is plasticlike, and the structure of a Bailey-Orowan creep theory when the response is creeplike.

  17. Analysis of the impact of simulation model simplifications on the quality of low-energy buildings simulation results

    NASA Astrophysics Data System (ADS)

    Klimczak, Marcin; Bojarski, Jacek; Ziembicki, Piotr; Kęskiewicz, Piotr

    2017-11-01

    The requirements concerning energy performance of buildings and their internal installations, particularly HVAC systems, have been growing continuously in Poland and all over the world. The existing, traditional calculation methods following from the static heat exchange model are frequently not sufficient for a reasonable heating design of a building. Both in Poland and elsewhere in the world, methods and software are employed which allow a detailed simulation of the heating and moisture conditions in a building, and also an analysis of the performance of HVAC systems within a building. However, these systems are usually difficult in use and complex. In addition, the development of a simulation model that is sufficiently adequate to the real building requires considerable time involvement of a designer, is time-consuming and laborious. A simplification of the simulation model of a building renders it possible to reduce the costs of computer simulations. The paper analyses in detail the effect of introducing a number of different variants of the simulation model developed in Design Builder on the quality of final results obtained. The objective of this analysis is to find simplifications which allow obtaining simulation results which have an acceptable level of deviations from the detailed model, thus facilitating a quick energy performance analysis of a given building.

  18. Automated Simplification of Full Chemical Mechanisms

    NASA Technical Reports Server (NTRS)

    Norris, A. T.

    1997-01-01

    A code has been developed to automatically simplify full chemical mechanisms. The method employed is based on the Intrinsic Low Dimensional Manifold (ILDM) method of Maas and Pope. The ILDM method is a dynamical systems approach to the simplification of large chemical kinetic mechanisms. By identifying low-dimensional attracting manifolds, the method allows complex full mechanisms to be parameterized by just a few variables; in effect, generating reduced chemical mechanisms by an automatic procedure. These resulting mechanisms however, still retain all the species used in the full mechanism. Full and skeletal mechanisms for various fuels are simplified to a two dimensional manifold, and the resulting mechanisms are found to compare well with the full mechanisms, and show significant improvement over global one step mechanisms, such as those by Westbrook and Dryer. In addition, by using an ILDM reaction mechanism in a CID code, a considerable improvement in turn-around time can be achieved.

  19. Appendix to HDC 2118 design criteria 100-X reactor water plant, general description - section II

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

    Not Available

    1952-03-29

    The factors responsible for the advances of 100-X compared with the older areas are: Simplification of the process, such as elimination of separate process water clearwells, by having the filtered water reservoirs perform that function. Combination of separate buildings into one building, such as combining filter pump house and process pump house. Use of electric standby. Use of higher capacity pumps and filter basins, and so fewer number of units. Centralization of control and operation. More compact arrangement of plant components. Use of waste heat for space heating, recovered from reactor effluent, backed up by steam plant.

  20. Modeling spatial competition for light in plant populations with the porous medium equation.

    PubMed

    Beyer, Robert; Etard, Octave; Cournède, Paul-Henry; Laurent-Gengoux, Pascal

    2015-02-01

    We consider a plant's local leaf area index as a spatially continuous variable, subject to particular reaction-diffusion dynamics of allocation, senescence and spatial propagation. The latter notably incorporates the plant's tendency to form new leaves in bright rather than shaded locations. Applying a generalized Beer-Lambert law allows to link existing foliage to production dynamics. The approach allows for inter-individual variability and competition for light while maintaining robustness-a key weakness of comparable existing models. The analysis of the single plant case leads to a significant simplification of the system's key equation when transforming it into the well studied porous medium equation. Confronting the theoretical model to experimental data of sugar beet populations, differing in configuration density, demonstrates its accuracy.

  1. Importance of disentanglement and entanglement during DNA replication and segregation. Comment on: "Disentangling DNA molecules" by Alexander Vologodskii

    NASA Astrophysics Data System (ADS)

    Bates, David; Pettitt, B. Montgomery; Buck, Gregory R.; Zechiedrich, Lynn

    2016-09-01

    In the Vologodskii review[19], the accompanying comments, and many other publications, there has been considerable effort to analyze the actions of type II topoisomerases, especially with regard to ;topological simplification; [4]. Whereas these efforts could be characterized as a battle of the models, with each research team arguing for their version of how it might work, each specific kinetic concept adds important considerations to the fundamental question of how these enzymes function. The basic tenet, however, of what is called the ;hooked juxtaposition model [1],; is not a modeling aspect, but is simply a geometric mathematical fact.

  2. A toy terrestrial carbon flow model

    NASA Technical Reports Server (NTRS)

    Parton, William J.; Running, Steven W.; Walker, Brian

    1992-01-01

    A generalized carbon flow model for the major terrestrial ecosystems of the world is reported. The model is a simplification of the Century model and the Forest-Biogeochemical model. Topics covered include plant production, decomposition and nutrient cycling, biomes, the utility of the carbon flow model for predicting carbon dynamics under global change, and possible applications to state-and-transition models and environmentally driven global vegetation models.

  3. Rational calculation accuracy in acousto-optical matrix-vector processor

    NASA Astrophysics Data System (ADS)

    Oparin, V. V.; Tigin, Dmitry V.

    1994-01-01

    The high speed of parallel computations for a comparatively small-size processor and acceptable power consumption makes the usage of acousto-optic matrix-vector multiplier (AOMVM) attractive for processing of large amounts of information in real time. The limited accuracy of computations is an essential disadvantage of such a processor. The reduced accuracy requirements allow for considerable simplification of the AOMVM architecture and the reduction of the demands on its components.

  4. Perineal template techniques for interstitial implantation of gynecological cancers using the Paris system of dosimetry

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

    Leung, S.

    1990-09-01

    Since 1984, perineal template/needle techniques for interstitial implantation of gynecologic cancer-cervix, vagina, vulva-have been developed at the Peter MacCallum Cancer Institute. The Paris System of dosimetry has been used resulting in greater dose homogeneity, fewer needles and radioactive sources and considerable simplification and ease of implantation compared with comparable techniques developed in the United States. Principles and techniques of implantation are described in detail.

  5. Text Simplification and Comprehensible Input: A Case for an Intuitive Approach

    ERIC Educational Resources Information Center

    Crossley, Scott A.; Allen, David; McNamara, Danielle S.

    2012-01-01

    Texts are routinely simplified to make them more comprehensible for second language learners. However, the effects of simplification upon the linguistic features of texts remain largely unexplored. Here we examine the effects of one type of text simplification: intuitive text simplification. We use the computational tool, Coh-Metrix, to examine…

  6. Designing agricultural landscapes for biodiversity-based ecosystem services

    DOE PAGES

    Landis, Douglas A.

    2016-07-28

    Sustainable and resilient agricultural systems are needed to feed and fuel a growing human population. However, the current model of agricultural intensification which produces high yields has also resulted in a loss of biodiversity, ecological function, and critical ecosystem services in agricultural landscapes. A key consequence of agricultural intensification is landscape simplification, where once heterogeneous landscapes contain increasingly fewer crop and non-crop habitats. Landscape simplification exacerbates biodiversity losses which leads to reductions in ecosystem services on which agriculture depends. In recent decades, considerable research has focused on mitigating these negative impacts, primarily via management of habitats to promote biodiversity andmore » enhance services at the local scale. While it is well known that local and landscape factors interact, modifying overall landscape structure is seldom considered due to logistical constraints. Here, I propose that the loss of ecosystem services due to landscape simplification can only be addressed by a concerted effort to fundamentally redesign agricultural landscapes. Designing agricultural landscapes will require that scientists work with stakeholders to determine the mix of desired ecosystem services, evaluate current landscape structure in light of those goals, and implement targeted modifications to achieve them. I evaluate the current status of landscape design, ranging from fundamental ecological principles to resulting guidelines and socioeconomic tools. Finally, while research gaps remain, the time is right for ecologists to engage with other disciplines, stakeholders, and policymakers in education and advocacy to foster agricultural landscape design for sustainable and resilient biodiversity services.« less

  7. Designing agricultural landscapes for biodiversity-based ecosystem services

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

    Landis, Douglas A.

    Sustainable and resilient agricultural systems are needed to feed and fuel a growing human population. However, the current model of agricultural intensification which produces high yields has also resulted in a loss of biodiversity, ecological function, and critical ecosystem services in agricultural landscapes. A key consequence of agricultural intensification is landscape simplification, where once heterogeneous landscapes contain increasingly fewer crop and non-crop habitats. Landscape simplification exacerbates biodiversity losses which leads to reductions in ecosystem services on which agriculture depends. In recent decades, considerable research has focused on mitigating these negative impacts, primarily via management of habitats to promote biodiversity andmore » enhance services at the local scale. While it is well known that local and landscape factors interact, modifying overall landscape structure is seldom considered due to logistical constraints. Here, I propose that the loss of ecosystem services due to landscape simplification can only be addressed by a concerted effort to fundamentally redesign agricultural landscapes. Designing agricultural landscapes will require that scientists work with stakeholders to determine the mix of desired ecosystem services, evaluate current landscape structure in light of those goals, and implement targeted modifications to achieve them. I evaluate the current status of landscape design, ranging from fundamental ecological principles to resulting guidelines and socioeconomic tools. Finally, while research gaps remain, the time is right for ecologists to engage with other disciplines, stakeholders, and policymakers in education and advocacy to foster agricultural landscape design for sustainable and resilient biodiversity services.« less

  8. Building simplification algorithms based on user cognition in mobile environment

    NASA Astrophysics Data System (ADS)

    Shen, Jie; Shi, Junfei; Wang, Meizhen; Wu, Chenyan

    2008-10-01

    With the development of LBS, mobile map should adaptively satisfy the cognitive requirement of user. User cognition in mobile environment is much more objective oriented and also seem to be a heavier burden than the user in static environment. The holistic idea and methods of map generalization can not fully suitable for the mobile map. This paper took the building simplification in habitation generalization as example, analyzed the characteristic of user cognition in mobile environment and the basic rules of building simplification, collected and studied the state-of-the-art of algorithms of building simplification in the static and mobile environment, put forward the idea of hierarchical building simplification based on user cognition. This paper took Hunan road business district of Nanjing as test area and took the building data with shapfile format of ESRI as test data and realized the simplification algorithm. The method took user as center, calculated the distance between user and the building which will be simplified and took the distance as the basis for choosing different simplification algorithm for different spaces. This contribution aimed to hierarchically present the building in different level of detail by real-time simplification.

  9. Casper W. Weinberger to be Secretary of Health, Education, and Welfare: Hearings Before the Committee on Labor and Public Welfare. United States Senate, Ninety-Third Congress. Part 2: Appendix--Comprehensive HEW Simplification and Reform "MEGA Proposal".

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Public Welfare.

    A proposal up for consideration before the United States Senate is discussed. The program suggested is a redesign of the Department of Health, Education, and Welfare in keeping with the principles of the New Federalism. The proposal touches every major area of HEW policy: it simplifies the Department's program structure; it narrows and focuses the…

  10. Simplification and improvement of protein detection in two-dimensional electrophoresis gels with SERVA HPE™ lightning red.

    PubMed

    Griebel, Anja; Obermaier, Christian; Westermeier, Reiner; Moche, Martin; Büttner, Knut

    2013-07-01

    A new fluorescent amino-reactive dye has been tested for both labelling proteins prior to electrophoretic separations and between the two steps of two-dimensional electrophoresis. A series of experiments showed, that the labelling of lysines with this dye is compatible with all standard additives used for sample preparation, including reducing substances and carrier ampholytes. Using this dye for pre-labelling considerably simplifies the electrophoresis and detection workflow and provides highly sensitive and quantitative visualisation of proteins.

  11. Spatial Self-Organization of Vegetation Subject to Climatic Stress-Insights from a System Dynamics-Individual-Based Hybrid Model.

    PubMed

    Vincenot, Christian E; Carteni, Fabrizio; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

    2016-01-01

    In simulation models of populations or communities, individual plants have often been obfuscated in favor of aggregated vegetation. This simplification comes with a loss of biological detail and a smoothing out of the demographic noise engendered by stochastic individual-scale processes and heterogeneities, which is significant among others when studying the viability of small populations facing challenging fluctuating environmental conditions. This consideration has motivated the development of precise plant-centered models. The accuracy gained in the representation of plant biology has then, however, often been balanced by the disappearance in models of important plant-soil interactions (esp. water dynamics) due to the inability of most individual-based frameworks to simulate complex continuous processes. In this study, we used a hybrid modeling approach, namely integrated System Dynamics (SD)-Individual-based (IB), to illustrate the importance of individual plant dynamics to explain spatial self-organization of vegetation in arid environments. We analyzed the behavior of this model under different parameter sets either related to individual plant properties (such as seed dispersal distance and reproductive age) or the environment (such as intensity and yearly distribution of precipitation events). While the results of this work confirmed the prevailing theory on vegetation patterning, they also revealed the importance therein of plant-level processes that cannot be rendered by reaction-diffusion models. Initial spatial distribution of plants, reproductive age, and average seed dispersal distance, by impacting patch size and vegetation aggregation, affected pattern formation and population survival under climatic variations. Besides, changes in precipitation regime altered the demographic structure and spatial organization of vegetation patches by affecting plants differentially depending on their age and biomass. Water availability influenced non-linearly total biomass density. Remarkably, lower precipitation resulted in lower mean plant age yet higher mean individual biomass. Moreover, seasonal variations in rainfall greater than a threshold (here, ±0.45 mm from the 1.3 mm baseline) decreased mean total biomass and generated limit cycles, which, in the case of large variations, were preceded by chaotic demographic and spatial behavior. In some cases, peculiar spatial patterns (e.g., rings) were also engendered. On a technical note, the shortcomings of the present model and the benefit of hybrid modeling for virtual investigations in plant science are discussed.

  12. Spatial Self-Organization of Vegetation Subject to Climatic Stress—Insights from a System Dynamics—Individual-Based Hybrid Model

    PubMed Central

    Vincenot, Christian E.; Carteni, Fabrizio; Mazzoleni, Stefano; Rietkerk, Max; Giannino, Francesco

    2016-01-01

    In simulation models of populations or communities, individual plants have often been obfuscated in favor of aggregated vegetation. This simplification comes with a loss of biological detail and a smoothing out of the demographic noise engendered by stochastic individual-scale processes and heterogeneities, which is significant among others when studying the viability of small populations facing challenging fluctuating environmental conditions. This consideration has motivated the development of precise plant-centered models. The accuracy gained in the representation of plant biology has then, however, often been balanced by the disappearance in models of important plant-soil interactions (esp. water dynamics) due to the inability of most individual-based frameworks to simulate complex continuous processes. In this study, we used a hybrid modeling approach, namely integrated System Dynamics (SD)—Individual-based (IB), to illustrate the importance of individual plant dynamics to explain spatial self-organization of vegetation in arid environments. We analyzed the behavior of this model under different parameter sets either related to individual plant properties (such as seed dispersal distance and reproductive age) or the environment (such as intensity and yearly distribution of precipitation events). While the results of this work confirmed the prevailing theory on vegetation patterning, they also revealed the importance therein of plant-level processes that cannot be rendered by reaction-diffusion models. Initial spatial distribution of plants, reproductive age, and average seed dispersal distance, by impacting patch size and vegetation aggregation, affected pattern formation and population survival under climatic variations. Besides, changes in precipitation regime altered the demographic structure and spatial organization of vegetation patches by affecting plants differentially depending on their age and biomass. Water availability influenced non-linearly total biomass density. Remarkably, lower precipitation resulted in lower mean plant age yet higher mean individual biomass. Moreover, seasonal variations in rainfall greater than a threshold (here, ±0.45 mm from the 1.3 mm baseline) decreased mean total biomass and generated limit cycles, which, in the case of large variations, were preceded by chaotic demographic and spatial behavior. In some cases, peculiar spatial patterns (e.g., rings) were also engendered. On a technical note, the shortcomings of the present model and the benefit of hybrid modeling for virtual investigations in plant science are discussed. PMID:27252707

  13. Advancing Crop Transformation in the Era of Genome Editing[OPEN

    PubMed Central

    Blechl, Ann E.; Brutnell, Thomas P.; Conrad, Liza J.; Gelvin, Stanton B.; Jackson, David P.; Kausch, Albert P.; Lemaux, Peggy G.; Medford, June I.; Orozco-Cárdenas, Martha L.; Tricoli, David M.; Van Eck, Joyce; Voytas, Daniel F.

    2016-01-01

    Plant transformation has enabled fundamental insights into plant biology and revolutionized commercial agriculture. Unfortunately, for most crops, transformation and regeneration remain arduous even after more than 30 years of technological advances. Genome editing provides novel opportunities to enhance crop productivity but relies on genetic transformation and plant regeneration, which are bottlenecks in the process. Here, we review the state of plant transformation and point to innovations needed to enable genome editing in crops. Plant tissue culture methods need optimization and simplification for efficiency and minimization of time in culture. Currently, specialized facilities exist for crop transformation. Single-cell and robotic techniques should be developed for high-throughput genomic screens. Plant genes involved in developmental reprogramming, wound response, and/or homologous recombination should be used to boost the recovery of transformed plants. Engineering universal Agrobacterium tumefaciens strains and recruiting other microbes, such as Ensifer or Rhizobium, could facilitate delivery of DNA and proteins into plant cells. Synthetic biology should be employed for de novo design of transformation systems. Genome editing is a potential game-changer in crop genetics when plant transformation systems are optimized. PMID:27335450

  14. Synoptic evaluation of scale-dependent metrics for hydrographic line feature geometry

    USGS Publications Warehouse

    Stanislawski, Larry V.; Buttenfield, Barbara P.; Raposo, Paulo; Cameron, Madeline; Falgout, Jeff T.

    2015-01-01

    Methods of acquisition and feature simplification for vector feature data impact cartographic representations and scientific investigations of these data, and are therefore important considerations for geographic information science (Haunert and Sester 2008). After initial collection, linear features may be simplified to reduce excessive detail or to furnish a reduced-scale version of the features through cartographic generalization (Regnauld and McMaster 2008, Stanislawski et al. 2014). A variety of algorithms exist to simplify linear cartographic features, and all of the methods affect the positional accuracy of the features (Shahriari and Tao 2002, Regnauld and McMaster 2008, Stanislawski et al. 2012). In general, simplification operations are controlled by one or more tolerance parameters that limit the amount of positional change the operation can make to features. Using a single tolerance value can have varying levels of positional change on features; depending on local shape, texture, or geometric characteristics of the original features (McMaster and Shea 1992, Shahriari and Tao 2002, Buttenfield et al. 2010). Consequently, numerous researchers have advocated calibration of simplification parameters to control quantifiable properties of resulting changes to the features (Li and Openshaw 1990, Raposo 2013, Tobler 1988, Veregin 2000, and Buttenfield, 1986, 1989).This research identifies relations between local topographic conditions and geometric characteristics of linear features that are available in the National Hydrography Dataset (NHD). The NHD is a comprehensive vector dataset of surface 18 th ICA Workshop on Generalisation and Multiple Representation, Rio de Janiero, Brazil 2015 2 water features within the United States that is maintained by the U.S. Geological Survey (USGS). In this paper, geometric characteristics of cartographic representations for natural stream and river features are summarized for subbasin watersheds within entire regions of the conterminous United States and compared to topographic metrics. A concurrent processing workflow is implemented using a Linux high-performance computing cluster to simultaneously process multiple subbasins, and thereby complete the work in a fraction of the time required for a single-process environment. In addition, similar metrics are generated for several levels of simplification of the hydrographic features to quantify the effects of simplification over the various landscape conditions. Objectives of this exploratory investigation are to quantify geometric characteristics of linear hydrographic features over the various terrain conditions within the conterminous United States and thereby illuminate relations between stream geomorphological conditions and cartographic representation. The synoptic view of these characteristics over regional watersheds that is afforded through concurrent processing, in conjunction with terrain conditions, may reveal patterns for classifying cartographic stream features into stream geomorphological classes. Furthermore, the synoptic measurement of the amount of change in geometric characteristics caused by the several levels of simplification can enable estimation of tolerance values that appropriately control simplification-induced geometric change of the cartographic features within the various geomorphological classes in the country. Hence, these empirically derived rules or relations could help generate multiscale-representations of features through automated generalization that adequately maintain surface drainage variations and patterns reflective of the natural stream geomorphological conditions across the country.

  15. Practical simplifications for radioimmunotherapy dosimetric models

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

    Shen, S.; DeNardo, G.L.; O`Donnell, R.T.

    1999-01-01

    Radiation dosimetry is potentially useful for assessment and prediction of efficacy and toxicity for radionuclide therapy. The usefulness of these dose estimates relies on the establishment of a dose-response model using accurate pharmacokinetic data and a radiation dosimetric model. Due to the complexity in radiation dose estimation, many practical simplifications have been introduced in the dosimetric modeling for clinical trials of radioimmunotherapy. Although research efforts are generally needed to improve the simplifications used at each stage of model development, practical simplifications are often possible for specific applications without significant consequences to the dose-response model. In the development of dosimetric methodsmore » for radioimmunotherapy, practical simplifications in the dosimetric models were introduced. This study evaluated the magnitude of uncertainty associated with practical simplifications for: (1) organ mass of the MIRD phantom; (2) radiation contribution from target alone; (3) interpolation of S value; (4) macroscopic tumor uniformity; and (5) fit of tumor pharmacokinetic data.« less

  16. Simplification.

    ERIC Educational Resources Information Center

    George, H. V.

    This article discusses language simplification as one aspect of a person's speech activity, and relates simplification to second language learning. Translation from language to language and translation within one language are processes through which a person, as decoder, decontextualizes a message form-sequence through perception of its…

  17. Robustness-Based Simplification of 2D Steady and Unsteady Vector Fields.

    PubMed

    Skraba, Primoz; Bei Wang; Guoning Chen; Rosen, Paul

    2015-08-01

    Vector field simplification aims to reduce the complexity of the flow by removing features in order of their relevance and importance, to reveal prominent behavior and obtain a compact representation for interpretation. Most existing simplification techniques based on the topological skeleton successively remove pairs of critical points connected by separatrices, using distance or area-based relevance measures. These methods rely on the stable extraction of the topological skeleton, which can be difficult due to instability in numerical integration, especially when processing highly rotational flows. In this paper, we propose a novel simplification scheme derived from the recently introduced topological notion of robustness which enables the pruning of sets of critical points according to a quantitative measure of their stability, that is, the minimum amount of vector field perturbation required to remove them. This leads to a hierarchical simplification scheme that encodes flow magnitude in its perturbation metric. Our novel simplification algorithm is based on degree theory and has minimal boundary restrictions. Finally, we provide an implementation under the piecewise-linear setting and apply it to both synthetic and real-world datasets. We show local and complete hierarchical simplifications for steady as well as unsteady vector fields.

  18. Complete DNA sequences of the plastid genomes of two parasitic flowering plant species, Cuscuta reflexa and Cuscuta gronovii.

    PubMed

    Funk, Helena T; Berg, Sabine; Krupinska, Karin; Maier, Uwe G; Krause, Kirsten

    2007-08-22

    The holoparasitic plant genus Cuscuta comprises species with photosynthetic capacity and functional chloroplasts as well as achlorophyllous and intermediate forms with restricted photosynthetic activity and degenerated chloroplasts. Previous data indicated significant differences with respect to the plastid genome coding capacity in different Cuscuta species that could correlate with their photosynthetic activity. In order to shed light on the molecular changes accompanying the parasitic lifestyle, we sequenced the plastid chromosomes of the two species Cuscuta reflexa and Cuscuta gronovii. Both species are capable of performing photosynthesis, albeit with varying efficiencies. Together with the plastid genome of Epifagus virginiana, an achlorophyllous parasitic plant whose plastid genome has been sequenced, these species represent a series of progression towards total dependency on the host plant, ranging from reduced levels of photosynthesis in C. reflexa to a restricted photosynthetic activity and degenerated chloroplasts in C. gronovii to an achlorophyllous state in E. virginiana. The newly sequenced plastid genomes of C. reflexa and C. gronovii reveal that the chromosome structures are generally very similar to that of non-parasitic plants, although a number of species-specific insertions, deletions (indels) and sequence inversions were identified. However, we observed a gradual adaptation of the plastid genome to the different degrees of parasitism. The changes are particularly evident in C. gronovii and include (a) the parallel losses of genes for the subunits of the plastid-encoded RNA polymerase and the corresponding promoters from the plastid genome, (b) the first documented loss of the gene for a putative splicing factor, MatK, from the plastid genome and (c) a significant reduction of RNA editing. Overall, the comparative genomic analysis of plastid DNA from parasitic plants indicates a bias towards a simplification of the plastid gene expression machinery as a consequence of an increasing dependency on the host plant. A tentative assignment of the successive events in the adaptation of the plastid genomes to parasitism can be inferred from the current data set. This includes (1) a loss of non-coding regions in photosynthetic Cuscuta species that has resulted in a condensation of the plastid genome, (2) the simplification of plastid gene expression in species with largely impaired photosynthetic capacity and (3) the deletion of a significant part of the genetic information, including the information for the photosynthetic apparatus, in non-photosynthetic parasitic plants.

  19. Complete DNA sequences of the plastid genomes of two parasitic flowering plant species, Cuscuta reflexa and Cuscuta gronovii

    PubMed Central

    Funk, Helena T; Berg, Sabine; Krupinska, Karin; Maier, Uwe G; Krause, Kirsten

    2007-01-01

    Background The holoparasitic plant genus Cuscuta comprises species with photosynthetic capacity and functional chloroplasts as well as achlorophyllous and intermediate forms with restricted photosynthetic activity and degenerated chloroplasts. Previous data indicated significant differences with respect to the plastid genome coding capacity in different Cuscuta species that could correlate with their photosynthetic activity. In order to shed light on the molecular changes accompanying the parasitic lifestyle, we sequenced the plastid chromosomes of the two species Cuscuta reflexa and Cuscuta gronovii. Both species are capable of performing photosynthesis, albeit with varying efficiencies. Together with the plastid genome of Epifagus virginiana, an achlorophyllous parasitic plant whose plastid genome has been sequenced, these species represent a series of progression towards total dependency on the host plant, ranging from reduced levels of photosynthesis in C. reflexa to a restricted photosynthetic activity and degenerated chloroplasts in C. gronovii to an achlorophyllous state in E. virginiana. Results The newly sequenced plastid genomes of C. reflexa and C. gronovii reveal that the chromosome structures are generally very similar to that of non-parasitic plants, although a number of species-specific insertions, deletions (indels) and sequence inversions were identified. However, we observed a gradual adaptation of the plastid genome to the different degrees of parasitism. The changes are particularly evident in C. gronovii and include (a) the parallel losses of genes for the subunits of the plastid-encoded RNA polymerase and the corresponding promoters from the plastid genome, (b) the first documented loss of the gene for a putative splicing factor, MatK, from the plastid genome and (c) a significant reduction of RNA editing. Conclusion Overall, the comparative genomic analysis of plastid DNA from parasitic plants indicates a bias towards a simplification of the plastid gene expression machinery as a consequence of an increasing dependency on the host plant. A tentative assignment of the successive events in the adaptation of the plastid genomes to parasitism can be inferred from the current data set. This includes (1) a loss of non-coding regions in photosynthetic Cuscuta species that has resulted in a condensation of the plastid genome, (2) the simplification of plastid gene expression in species with largely impaired photosynthetic capacity and (3) the deletion of a significant part of the genetic information, including the information for the photosynthetic apparatus, in non-photosynthetic parasitic plants. PMID:17714582

  20. Simplifications of the mini nutritional assessment short-form are predictive of mortality among hospitalized young and middle-aged adults.

    PubMed

    Asiimwe, Stephen B

    2016-01-01

    Measuring malnutrition in hospitalized patients is difficult in all settings. I evaluated associations of items in the mini nutritional assessment short-form (MNA-sf), a nutritional-risk screening tool previously validated in the elderly, with malnutrition among hospitalized patients in Uganda. I used results to construct two simplifications of this tool that may be applicable to young and middle-aged adults. I assessed the association of each MNA-sf item with the mid-upper arm circumference (MUAC), a specific measure of malnutrition at appropriate cut-offs. I incorporated only malnutrition-specific items into the proposed simplifications scoring each item according to its association with malnutrition. I assessed numbers classified to different score-levels by the simplifications and, via proportional hazards regression, how the simplifications predicted in-hospital mortality. I analyzed 318 patients (median age 37, interquartile range 27 to 56). Variables making it into the simplifications were: reduced food intake, weight loss, mobility, and either BMI in kg/m(2) (categorized as <16, 16 to 16.9, and ≥17) or MUAC in centimeters (categorized as <16 or <17, 16 to 18.9 or 17 to 19.9, and ≥19 or ≥20 for females and males respectively). Compared to the traditional MNA-sf, the simplifications classified fewer patients as malnourished, yet remained strongly predictive of in-hospital mortality. In the MUAC-incorporating simplification, malnourished patients had 3.8-fold (95% CI 1.9 to 7.8) higher risk of in-hospital death than those not malnourished; adjusting for age, sex, and HIV status. The MNA-sf simplifications described may provide an improved measure of malnutrition in hospitalized young and middle-aged adults. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Advancing Crop Transformation in the Era of Genome Editing.

    PubMed

    Altpeter, Fredy; Springer, Nathan M; Bartley, Laura E; Blechl, Ann E; Brutnell, Thomas P; Citovsky, Vitaly; Conrad, Liza J; Gelvin, Stanton B; Jackson, David P; Kausch, Albert P; Lemaux, Peggy G; Medford, June I; Orozco-Cárdenas, Martha L; Tricoli, David M; Van Eck, Joyce; Voytas, Daniel F; Walbot, Virginia; Wang, Kan; Zhang, Zhanyuan J; Stewart, C Neal

    2016-07-01

    Plant transformation has enabled fundamental insights into plant biology and revolutionized commercial agriculture. Unfortunately, for most crops, transformation and regeneration remain arduous even after more than 30 years of technological advances. Genome editing provides novel opportunities to enhance crop productivity but relies on genetic transformation and plant regeneration, which are bottlenecks in the process. Here, we review the state of plant transformation and point to innovations needed to enable genome editing in crops. Plant tissue culture methods need optimization and simplification for efficiency and minimization of time in culture. Currently, specialized facilities exist for crop transformation. Single-cell and robotic techniques should be developed for high-throughput genomic screens. Plant genes involved in developmental reprogramming, wound response, and/or homologous recombination should be used to boost the recovery of transformed plants. Engineering universal Agrobacterium tumefaciens strains and recruiting other microbes, such as Ensifer or Rhizobium, could facilitate delivery of DNA and proteins into plant cells. Synthetic biology should be employed for de novo design of transformation systems. Genome editing is a potential game-changer in crop genetics when plant transformation systems are optimized. © 2016 American Society of Plant Biologists. All rights reserved.

  2. Rainbow tensor model with enhanced symmetry and extreme melonic dominance

    NASA Astrophysics Data System (ADS)

    Itoyama, H.; Mironov, A.; Morozov, A.

    2017-08-01

    We introduce and briefly analyze the rainbow tensor model where all planar diagrams are melonic. This leads to considerable simplification of the large N limit as compared to that of the matrix model: in particular, what are dressed in this limit are propagators only, which leads to an oversimplified closed set of Schwinger-Dyson equations for multi-point correlators. We briefly touch upon the Ward identities, the substitute of the spectral curve and the AMM/EO topological recursion and their possible connections to Connes-Kreimer theory and forest formulas.

  3. A linear model of population dynamics

    NASA Astrophysics Data System (ADS)

    Lushnikov, A. A.; Kagan, A. I.

    2016-08-01

    The Malthus process of population growth is reformulated in terms of the probability w(n,t) to find exactly n individuals at time t assuming that both the birth and the death rates are linear functions of the population size. The master equation for w(n,t) is solved exactly. It is shown that w(n,t) strongly deviates from the Poisson distribution and is expressed in terms either of Laguerre’s polynomials or a modified Bessel function. The latter expression allows for considerable simplifications of the asymptotic analysis of w(n,t).

  4. Lagrangian methods in nonlinear plasma wave interaction

    NASA Technical Reports Server (NTRS)

    Crawford, F. W.

    1980-01-01

    Analysis of nonlinear plasma wave interactions is usually very complicated, and simplifying mathematical approaches are highly desirable. The application of averaged-Lagrangian methods offers a considerable reduction in effort, with improved insight into synchronism and conservation (Manley-Rowe) relations. This chapter indicates how suitable Lagrangian densities have been defined, expanded, and manipulated to describe nonlinear wave-wave and wave-particle interactions in the microscopic, macroscopic and cold plasma models. Recently, further simplifications have been introduced by the use of techniques derived from Lie algebra. These and likely future developments are reviewed briefly.

  5. Simplification: A Viewpoint in Outline. Appendix.

    ERIC Educational Resources Information Center

    Tickoo, Makhan L.

    This essay examines language simplification for second language learners as a linguistic and a pedagogic phenomenon, posing questions for further study by considering past research. It discusses linguistic simplification (LS) in relation to the development of artificial languages, such as Esperanto, "pidgin" languages, Basic English,…

  6. 7 CFR 3015.311 - Simplification, consolidation, or substitution of State plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Simplification, consolidation, or substitution of... (Continued) OFFICE OF THE CHIEF FINANCIAL OFFICER, DEPARTMENT OF AGRICULTURE UNIFORM FEDERAL ASSISTANCE... Simplification, consolidation, or substitution of State plans. (a) As used in this section: (1) Simplify means...

  7. Soil Eukaryotic Microorganism Succession as Affected by Continuous Cropping of Peanut - Pathogenic and Beneficial Fungi were Selected

    PubMed Central

    Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

    2012-01-01

    Peanut is an important oil crop worldwide and shows considerable adaptability but growth and yield are negatively affected by continuous cropping. Soil micro-organisms are efficient bio-indicators of soil quality and plant health and are critical to the sustainability of soil-based ecosystem function and to successful plant growth. In this study, 18S rRNA gene clone library analyses were employed to study the succession progress of soil eukaryotic micro-organisms under continuous peanut cultivation. Eight libraries were constructed for peanut over three continuous cropping cycles and its representative growth stages. Cluster analyses indicated that soil micro-eukaryotic assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. Six eukaryotic groups were found and fungi predominated in all libraries. The fungal populations showed significant dynamic change and overall diversity increased over time under continuous peanut cropping. The abundance and/or diversity of clones affiliated with Eurotiales, Hypocreales, Glomerales, Orbiliales, Mucorales and Tremellales showed an increasing trend with continuous cropping but clones affiliated with Agaricales, Cantharellales, Pezizales and Pyxidiophorales decreased in abundance and/or diversity over time. The current data, along with data from previous studies, demonstrated that the soil microbial community was affected by continuous cropping, in particular, the pathogenic and beneficial fungi that were positively selected over time, which is commonplace in agro-ecosystems. The trend towards an increase in fungal pathogens and simplification of the beneficial fungal community could be important factors contributing to the decline in peanut growth and yield over many years of continuous cropping. PMID:22808226

  8. Variable structure control of nonlinear systems through simplified uncertain models

    NASA Technical Reports Server (NTRS)

    Sira-Ramirez, Hebertt

    1986-01-01

    A variable structure control approach is presented for the robust stabilization of feedback equivalent nonlinear systems whose proposed model lies in the same structural orbit of a linear system in Brunovsky's canonical form. An attempt to linearize exactly the nonlinear plant on the basis of the feedback control law derived for the available model results in a nonlinearly perturbed canonical system for the expanded class of possible equivalent control functions. Conservatism tends to grow as modeling errors become larger. In order to preserve the internal controllability structure of the plant, it is proposed that model simplification be carried out on the open-loop-transformed system. As an example, a controller is developed for a single link manipulator with an elastic joint.

  9. A Simplified Biosphere Model for Global Climate Studies.

    NASA Astrophysics Data System (ADS)

    Xue, Y.; Sellers, P. J.; Kinter, J. L.; Shukla, J.

    1991-03-01

    The Simple Biosphere Model (SiB) as described in Sellers et al. is a bio-physically based model of land surface-atmosphere interaction. For some general circulation model (GCM) climate studies, further simplifications are desirable to have greater computation efficiency, and more important, to consolidate the parametric representation. Three major reductions in the complexity of SiB have been achieved in the present study.The diurnal variation of surface albedo is computed in SiB by means of a comprehensive yet complex calculation. Since the diurnal cycle is quite regular for each vegetation type, this calculation can be simplified considerably. The effect of root zone soil moisture on stomatal resistance is substantial, but the computation in SiB is complicated and expensive. We have developed approximations, which simulate the effects of reduced soil moisture more simply, keeping the essence of the biophysical concepts used in SiB.The surface stress and the fluxes of heat and moisture between the top of the vegetation canopy and an atmospheric reference level have been parameterized in an off-line version of SiB based upon the studies by Businger et al. and Paulson. We have developed a linear relationship between Richardson number and aero-dynamic resistance. Finally, the second vegetation layer of the original model does not appear explicitly after simplification. Compared to the model of Sellers et al., we have reduced the number of input parameters from 44 to 21. A comparison of results using the reduced parameter biosphere with those from the original formulation in a GCM and a zero-dimensional model shows the simplified version to reproduce the original results quite closely. After simplification, the computational requirement of SiB was reduced by about 55%.

  10. Selected configuration tradeoffs of contour optical instruments

    NASA Astrophysics Data System (ADS)

    Warren, J.; Strohbehn, K.; Murchie, S.; Fort, D.; Reynolds, E.; Heyler, G.; Peacock, K.; Boldt, J.; Darlington, E.; Hayes, J.; Henshaw, R.; Izenberg, N.; Kardian, C.; Lees, J.; Lohr, D.; Mehoke, D.; Schaefer, E.; Sholar, T.; Spisz, T.; Willey, C.; Veverka, J.; Bell, J.; Cochran, A.

    2003-01-01

    The Comet Nucleus Tour (CONTOUR) is a low-cost NASA Discovery mission designed to conduct three close flybys of comet nuclei. Selected configuration tradeoffs conducted to balance science requirements with low mission cost are reviewed. The tradeoffs discussed focus on the optical instruments and related spacecraft considerations. Two instruments are under development. The CONTOUR Forward Imager (CFI) is designed to perform optical navigation, moderate resolution nucleus/jet imaging, and imaging of faint molecular emission bands in the coma. The CONTOUR Remote Imager and Spectrometer (CRISP) is designed to obtain high-resolution multispectral images of the nucleus, conduct spectral mapping of the nucleus surface, and provide a backup optical navigation capability. Tradeoffs discussed are: (1) the impact on the optical instruments of not using reaction wheels on the spacecraft, (2) the improved performance and simplification gained by implementing a dedicated star tracker instead of including this function in CFI, (3) the improved flexibility and robustness of switching to a low frame rate tracker for CRISP, (4) the improved performance and simplification of replacing a visible imaging spectrometer by enhanced multispectral imaging in CRISP, and (5) the impact on spacecraft resources of these and other tradeoffs.

  11. The Dynamic Characteristic and Hysteresis Effect of an Air Spring

    NASA Astrophysics Data System (ADS)

    Löcken, F.; Welsch, M.

    2015-02-01

    In many applications of vibration technology, especially in chassis, air springs present a common alternative to steel spring concepts. A design-independent and therefore universal approach is presented to describe the dynamic characteristic of such springs. Differential and constitutive equations based on energy balances of the enclosed volume and the mountings are given to describe the nonlinear and dynamic characteristics. Therefore all parameters can be estimated directly from physical and geometrical properties, without parameter fitting. The numerically solved equations fit very well to measurements of a passenger car air spring. In a second step a simplification of this model leads to a pure mechanical equation. While in principle the same parameters are used, just an empirical correction of the effective heat transfer coefficient is needed to handle some simplification on this topic. Finally, a linearization of this equation leads to an analogous mechanical model that can be assembled from two common spring- and one dashpot elements in a specific arrangement. This transfer into "mechanical language" enables a system description with a simple force-displacement law and a consideration of the nonobvious hysteresis and stiffness increase of an air spring from a mechanical point of view.

  12. Simplifications and Idealizations in High School Physics in Mechanics: A Study of Slovenian Curriculum and Textbooks

    ERIC Educational Resources Information Center

    Forjan, Matej; Sliško, Josip

    2014-01-01

    This article presents the results of an analysis of three Slovenian textbooks for high school physics, from the point of view of simplifications and idealizations in the field of mechanics. In modeling of physical systems, making simplifications and idealizations is important, since one ignores minor effects and focuses on the most important…

  13. Complicity as Infiltration: The (Im)possibilities of Research with/in NSF Engineering Grants in the Age of Neoliberal Scientism

    ERIC Educational Resources Information Center

    Daza, Stephanie Lynn

    2012-01-01

    In this article, I use a Spivakian decolonizing perspective to take simplification to task in two ways--the simplification of methodology with/in grants and the simplification of critique that skirts the impossibility of noncomplicitous research and researchers. I posit that "neoliberal scientism"'s grants culture is colonizing research--narrowly…

  14. Symbolic manipulation techniques for vibration analysis of laminated elliptic plates

    NASA Technical Reports Server (NTRS)

    Andersen, C. M.; Noor, A. K.

    1977-01-01

    A computational scheme is presented for the free vibration analysis of laminated composite elliptic plates. The scheme is based on Hamilton's principle, the Rayleigh-Ritz technique and symmetry considerations and is implemented with the aid of the MACSYMA symbolic manipulation system. The MACYSMA system, through differentiation, integration, and simplification of analytic expressions, produces highly-efficient FORTRAN code for the evaluation of the stiffness and mass coefficients. Multiple use is made of this code to obtain not only the frequencies and mode shapes of the plate, but also the derivatives of the frequencies with respect to various material and geometric parameters.

  15. Discuss the impact technological advances in equipment and materials have made on the delivery and outcome of endodontic treatment.

    PubMed

    Lababidi, Emad Aldin

    2013-12-01

    Recent advances in endodontic equipment and materials have considerably changed the manner in which endodontic treatment is delivered. Specific technological advances, including nickel-titanium instruments, ultrasonic instruments and the dental operating microscope have been associated with increased efficiency and efficacy of treatment and simplification of delivery. The effects of most of these changes have been tested via in vitro studies and case reports. Ongoing studies should constantly investigate what effects technological advances might have on the outcome of endodontic treatment. © 2013 Australian Society of Endodontology.

  16. Method for detecting trace impurities in gases

    DOEpatents

    Freund, Samuel M.; Maier, II, William B.; Holland, Redus F.; Beattie, Willard H.

    1981-01-01

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (.about.2 ppm) present in commercial Xe and ppm levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  17. Method for detecting trace impurities in gases

    DOEpatents

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  18. EPRI/DOE High-Burnup Fuel Sister Rod Test Plan Simplification and Visualization

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

    Saltzstein, Sylvia J.; Sorenson, Ken B.; Hanson, B. D.

    The EPRI/DOE High-Burnup Confirmatory Data Project (herein called the “Demo”) is a multi-year, multi-entity test with the purpose of providing quantitative and qualitative data to show if high-burnup fuel mechanical properties change in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of common cladding alloys from the North Anna Nuclear Power Plant, loading them in an NRC-licensed TN-32B cask, drying them according to standard plant procedures, and then storing them on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened and themore » mechanical properties of the rods will be tested and analyzed.« less

  19. Oversimplifying quantum factoring.

    PubMed

    Smolin, John A; Smith, Graeme; Vargo, Alexander

    2013-07-11

    Shor's quantum factoring algorithm exponentially outperforms known classical methods. Previous experimental implementations have used simplifications dependent on knowing the factors in advance. However, as we show here, all composite numbers admit simplification of the algorithm to a circuit equivalent to flipping coins. The difficulty of a particular experiment therefore depends on the level of simplification chosen, not the size of the number factored. Valid implementations should not make use of the answer sought.

  20. Hybrid stochastic simplifications for multiscale gene networks.

    PubMed

    Crudu, Alina; Debussche, Arnaud; Radulescu, Ovidiu

    2009-09-07

    Stochastic simulation of gene networks by Markov processes has important applications in molecular biology. The complexity of exact simulation algorithms scales with the number of discrete jumps to be performed. Approximate schemes reduce the computational time by reducing the number of simulated discrete events. Also, answering important questions about the relation between network topology and intrinsic noise generation and propagation should be based on general mathematical results. These general results are difficult to obtain for exact models. We propose a unified framework for hybrid simplifications of Markov models of multiscale stochastic gene networks dynamics. We discuss several possible hybrid simplifications, and provide algorithms to obtain them from pure jump processes. In hybrid simplifications, some components are discrete and evolve by jumps, while other components are continuous. Hybrid simplifications are obtained by partial Kramers-Moyal expansion [1-3] which is equivalent to the application of the central limit theorem to a sub-model. By averaging and variable aggregation we drastically reduce simulation time and eliminate non-critical reactions. Hybrid and averaged simplifications can be used for more effective simulation algorithms and for obtaining general design principles relating noise to topology and time scales. The simplified models reproduce with good accuracy the stochastic properties of the gene networks, including waiting times in intermittence phenomena, fluctuation amplitudes and stationary distributions. The methods are illustrated on several gene network examples. Hybrid simplifications can be used for onion-like (multi-layered) approaches to multi-scale biochemical systems, in which various descriptions are used at various scales. Sets of discrete and continuous variables are treated with different methods and are coupled together in a physically justified approach.

  1. Traditional Lebanese recipes based on wild plants: an answer to diet simplification?

    PubMed

    Batal, Malek; Hunter, Elizabeth

    2007-06-01

    The challenge posed by the nutrition transition occurring throughout the world is enormous: rates of chronic disease, particularly overweight and obesity and cardiovascular disease, have reached alarming levels-often occurring in parallel with high levels of micronutrient deficiencies. Lebanon is no exception. And yet this Mediterranean country enjoys a rich biodiversity, with thousands of endemic species and an equally rich culinary history, largely based on its local biodiversity, including wild edible plants. To record traditional Lebanese recipes based on wild edible plants and to investigate their potential to contribute to a more diversified diet. A series of nine focus group meetings was conducted with key informants knowledgeable in wild edible plant identification, harvesting, and use. Common recipes based on wild edible plants were collected and standardized from rural communities where collection of wild edible plants is common. Nutrient analysis and food-composition analysis were performed, including comparisons with processed dishes that are increasingly common in the Lebanese diet, revealing that the wild edible plant-based dishes offered a healthier alternative. Since traditional recipes often use items from several food groups in one dish, they can be a good model for diet diversification. The promotion of the collection and use of wild edible plants and their derived products can lead to improved nutrition.

  2. Enzyme-driven metabolomic screening: a proof-of-principle method for discovery of plant defence compounds targeted by pathogens.

    PubMed

    Carere, Jason; Colgrave, Michelle L; Stiller, Jiri; Liu, Chunji; Manners, John M; Kazan, Kemal; Gardiner, Donald M

    2016-11-01

    Plants produce a variety of secondary metabolites to defend themselves from pathogen attack, while pathogens have evolved to overcome plant defences by producing enzymes that degrade or modify these defence compounds. However, many compounds targeted by pathogen enzymes currently remain enigmatic. Identifying host compounds targeted by pathogen enzymes would enable us to understand the potential importance of such compounds in plant defence and modify them to make them insensitive to pathogen enzymes. Here, a proof of concept metabolomics-based method was developed to discover plant defence compounds modified by pathogens using two pathogen enzymes with known targets in wheat and tomato. Plant extracts treated with purified pathogen enzymes were subjected to LC-MS, and the relative abundance of metabolites before and after treatment were comparatively analysed. Using two enzymes from different pathogens the in planta targets could be found by combining relatively simple enzymology with the power of untargeted metabolomics. Key to the method is dataset simplification based on natural isotope occurrence and statistical filtering, which can be scripted. The method presented here will aid in our understanding of plant-pathogen interactions and may lead to the development of new plant protection strategies. © 2016 CSIRO. New Phytologist © 2016 New Phytologist Trust.

  3. Dynamic Succession of Soil Bacterial Community during Continuous Cropping of Peanut (Arachis hypogaea L.)

    PubMed Central

    Chen, Mingna; Li, Xiao; Yang, Qingli; Chi, Xiaoyuan; Pan, Lijuan; Chen, Na; Yang, Zhen; Wang, Tong; Wang, Mian; Yu, Shanlin

    2014-01-01

    Plant health and soil fertility are affected by plant–microbial interactions in soils. Peanut is an important oil crop worldwide and shows considerable adaptability, but growth and yield are negatively affected by continuous cropping. In this study, 16S rRNA gene clone library analyses were used to study the succession of soil bacterial communities under continuous peanut cultivation. Six libraries were constructed for peanut over three continuous cropping cycles and during its seedling and pod-maturing growth stages. Cluster analyses indicated that soil bacterial assemblages obtained from the same peanut cropping cycle were similar, regardless of growth period. The diversity of bacterial sequences identified in each growth stage library of the three peanut cropping cycles was high and these sequences were affiliated with 21 bacterial groups. Eight phyla: Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Gemmatimonadetes, Planctomycetes, Proteobacteria and Verrucomicrobia were dominant. The related bacterial phylotypes dynamic changed during continuous cropping progress of peanut. This study demonstrated that the bacterial populations especially the beneficial populations were positively selected. The simplification of the beneficial microbial communities such as the phylotypes of Alteromonadales, Burkholderiales, Flavobacteriales, Pseudomonadales, Rhizobiales and Rhodospirillales could be important factors contributing to the decline in peanut yield under continuous cropping. The microbial phylotypes that did not successively changed with continuous cropping, such as populations related to Rhizobiales and Rhodospirillales, could potentially resist stress due to continuous cropping and deserve attention. In addition, some phylotypes, such as Acidobacteriales, Chromatiales and Gemmatimonadales, showed a contrary tendency, their abundance or diversity increased with continuous peanut cropping progress. Some bacterial phylotypes including Acidobacteriales, Burkholderiales, Bdellovibrionales, and so on, also were affected by plant age. PMID:25010658

  4. Hybrid stochastic simplifications for multiscale gene networks

    PubMed Central

    Crudu, Alina; Debussche, Arnaud; Radulescu, Ovidiu

    2009-01-01

    Background Stochastic simulation of gene networks by Markov processes has important applications in molecular biology. The complexity of exact simulation algorithms scales with the number of discrete jumps to be performed. Approximate schemes reduce the computational time by reducing the number of simulated discrete events. Also, answering important questions about the relation between network topology and intrinsic noise generation and propagation should be based on general mathematical results. These general results are difficult to obtain for exact models. Results We propose a unified framework for hybrid simplifications of Markov models of multiscale stochastic gene networks dynamics. We discuss several possible hybrid simplifications, and provide algorithms to obtain them from pure jump processes. In hybrid simplifications, some components are discrete and evolve by jumps, while other components are continuous. Hybrid simplifications are obtained by partial Kramers-Moyal expansion [1-3] which is equivalent to the application of the central limit theorem to a sub-model. By averaging and variable aggregation we drastically reduce simulation time and eliminate non-critical reactions. Hybrid and averaged simplifications can be used for more effective simulation algorithms and for obtaining general design principles relating noise to topology and time scales. The simplified models reproduce with good accuracy the stochastic properties of the gene networks, including waiting times in intermittence phenomena, fluctuation amplitudes and stationary distributions. The methods are illustrated on several gene network examples. Conclusion Hybrid simplifications can be used for onion-like (multi-layered) approaches to multi-scale biochemical systems, in which various descriptions are used at various scales. Sets of discrete and continuous variables are treated with different methods and are coupled together in a physically justified approach. PMID:19735554

  5. A consistent positive association between landscape simplification and insecticide use across the Midwestern US from 1997 through 2012

    DOE PAGES

    Meehan, Timothy D.; Gratton, Claudio

    2015-10-27

    During 2007, counties across the Midwestern US with relatively high levels of landscape simplification (i.e., widespread replacement of seminatural habitats with cultivated crops) had relatively high crop-pest abundances which, in turn, were associated with relatively high insecticide application. These results suggested a positive relationship between landscape simplification and insecticide use, mediated by landscape effects on crop pests or their natural enemies. A follow-up study, in the same region but using different statistical methods, explored the relationship between landscape simplification and insecticide use between 1987 and 2007, and concluded that the relationship varied substantially in sign and strength across years. Here,more » we explore this relationship from 1997 through 2012, using a single dataset and two different analytical approaches. We demonstrate that, when using ordinary least squares (OLS) regression, the relationship between landscape simplification and insecticide use is, indeed, quite variable over time. However, the residuals from OLS models show strong spatial autocorrelation, indicating spatial structure in the data not accounted for by explanatory variables, and violating a standard assumption of OLS. When modeled using spatial regression techniques, relationships between landscape simplification and insecticide use were consistently positive between 1997 and 2012, and model fits were dramatically improved. We argue that spatial regression methods are more appropriate for these data, and conclude that there remains compelling correlative support for a link between landscape simplification and insecticide use in the Midwestern US. We discuss the limitations of inference from this and related studies, and suggest improved data collection campaigns for better understanding links between landscape structure, crop-pest pressure, and pest-management practices.« less

  6. A consistent positive association between landscape simplification and insecticide use across the Midwestern US from 1997 through 2012

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

    Meehan, Timothy D.; Gratton, Claudio

    During 2007, counties across the Midwestern US with relatively high levels of landscape simplification (i.e., widespread replacement of seminatural habitats with cultivated crops) had relatively high crop-pest abundances which, in turn, were associated with relatively high insecticide application. These results suggested a positive relationship between landscape simplification and insecticide use, mediated by landscape effects on crop pests or their natural enemies. A follow-up study, in the same region but using different statistical methods, explored the relationship between landscape simplification and insecticide use between 1987 and 2007, and concluded that the relationship varied substantially in sign and strength across years. Here,more » we explore this relationship from 1997 through 2012, using a single dataset and two different analytical approaches. We demonstrate that, when using ordinary least squares (OLS) regression, the relationship between landscape simplification and insecticide use is, indeed, quite variable over time. However, the residuals from OLS models show strong spatial autocorrelation, indicating spatial structure in the data not accounted for by explanatory variables, and violating a standard assumption of OLS. When modeled using spatial regression techniques, relationships between landscape simplification and insecticide use were consistently positive between 1997 and 2012, and model fits were dramatically improved. We argue that spatial regression methods are more appropriate for these data, and conclude that there remains compelling correlative support for a link between landscape simplification and insecticide use in the Midwestern US. We discuss the limitations of inference from this and related studies, and suggest improved data collection campaigns for better understanding links between landscape structure, crop-pest pressure, and pest-management practices.« less

  7. On the formulation of the aerodynamic characteristics in aircraft dynamics

    NASA Technical Reports Server (NTRS)

    Tobak, M.; Schiff, L. B.

    1976-01-01

    The theory of functionals is used to reformulate the notions of aerodynamic indicial functions and superposition. Integral forms for the aerodynamic response to arbitrary motions are derived that are free of dependence on a linearity assumption. Simplifications of the integral forms lead to practicable nonlinear generalizations of the linear superpositions and stability derivative formulations. Applied to arbitrary nonplanar motions, the generalization yields a form for the aerodynamic response that can be compounded of the contributions from a limited number of well-defined characteristic motions, in principle reproducible in the wind tunnel. Further generalizations that would enable the consideration of random fluctuations and multivalued aerodynamic responses are indicated.

  8. Simplification of the laser absorption process in the particle simulation for the laser-induced shockwave processing

    NASA Astrophysics Data System (ADS)

    Shimamura, Kohei

    2016-09-01

    To reduce the computational cost in the particle method for the numerical simulation of the laser plasma, we examined the simplification of the laser absorption process. Because the laser frequency is sufficiently larger than the collision frequency between the electron and heavy particles, we assumed that the electron obtained the constant value from the laser irradiation. First of all, the simplification of the laser absorption process was verified by the comparison of the EEDF and the laser-absorptivity with PIC-FDTD method. Secondary, the laser plasma induced by TEA CO2 laser in Argon atmosphere was modeled using the 1D3V DSMC method with the simplification of the laser-absorption. As a result, the LSDW was observed with the typical electron and neutral density distribution.

  9. Modelling Concentrating Solar Power with Thermal Energy Storage for Integration Studies (Presentation)

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

    Hummon, M.; Jorgenson, J.; Denholm, P.

    2013-10-01

    Concentrating solar power with thermal energy storage (CSP-TES) can provide multiple benefits to the grid, including low marginal cost energy and the ability to levelize load, provide operating reserves, and provide firm capacity. It is challenging to properly value the integration of CSP because of the complicated nature of this technology. Unlike completely dispatchable fossil sources, CSP is a limited energy resource, depending on the hourly and daily supply of solar energy. To optimize the use of this limited energy, CSP-TES must be implemented in a production cost model with multiple decision variables for the operation of the CSP-TES plant.more » We develop and implement a CSP-TES plant in a production cost model that accurately characterizes the three main components of the plant: solar field, storage tank, and power block. We show the effect of various modelling simplifications on the value of CSP, including: scheduled versus optimized dispatch from the storage tank and energy-only operation versus co-optimization with ancillary services.« less

  10. Modelling Concentrating Solar Power with Thermal Energy Storage for Integration Studies: Preprint

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

    Hummon, M.; Denholm, P.; Jorgenson, J.

    2013-10-01

    Concentrating solar power with thermal energy storage (CSP-TES) can provide multiple benefits to the grid, including low marginal cost energy and the ability to levelize load, provide operating reserves, and provide firm capacity. It is challenging to properly value the integration of CSP because of the complicated nature of this technology. Unlike completely dispatchable fossil sources, CSP is a limited energy resource, depending on the hourly and daily supply of solar energy. To optimize the use of this limited energy, CSP-TES must be implemented in a production cost model with multiple decision variables for the operation of the CSP-TES plant.more » We develop and implement a CSP-TES plant in a production cost model that accurately characterizes the three main components of the plant: solar field, storage tank, and power block. We show the effect of various modelling simplifications on the value of CSP, including: scheduled versus optimized dispatch from the storage tank and energy-only operation versus co-optimization with ancillary services.« less

  11. Synthesis of aromatic cytokinins for plant biotechnology.

    PubMed

    Plíhalová, Lucie; Vylíčilová, Hana; Doležal, Karel; Zahajská, Lenka; Zatloukal, Marek; Strnad, Miroslav

    2016-09-25

    Cytokinins represent an important group of plant growth regulators that can modulate several biotechnological processes owing to their ability to influence almost all stages of plant development and growth. In addition, the use of purine based cytokinins with aromatic substituent in C6 position of the purine moiety in tissue culture techniques is currently experiencing a surge in interest, made possible by the ongoing systematic synthesis and study of these compounds. This review article outlines progress in the synthesis of aromatic cytokinins, the in vitro and in vivo effects of these substances and insights gleaned from their synthesis. As the purine moiety in these compounds can be substituted at several positions, we examine each of the substitution possibilities in relation to the derivatives prepared so far. The discussion highlights the gradual simplification of their preparation in relation to their application in practice and summarizes the relevant organic chemistry literature and published patents. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Business not as usual

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Typical design simplification ideas which reduce costs; combustion chamber design simplification; combustion chambers; castings vs. machined and welded forgings; automated inspection; and life cycle costs are outlined. This presentation is represented by viewgraphs.

  13. Landscape simplification reduces classical biological control and crop yield.

    PubMed

    Grab, Heather; Danforth, Bryan; Poveda, Katja; Loeb, Greg

    2018-03-01

    Agricultural intensification resulting in the simplification of agricultural landscapes is known to negatively impact the delivery of key ecosystem services such as the biological control of crop pests. Both conservation and classical biological control may be influenced by the landscape context in which they are deployed; yet studies examining the role of landscape structure in the establishment and success of introduced natural enemies and their interactions with native communities are lacking. In this study, we investigated the relationship between landscape simplification, classical and conservation biological control services and importantly, the outcome of these interactions for crop yield. We showed that agricultural simplification at the landscape scale is associated with an overall reduction in parasitism rates of crop pests. Additionally, only introduced parasitoids were identified, and no native parasitoids were found in crop habitat, irrespective of agricultural landscape simplification. Pest densities in the crop were lower in landscapes with greater proportions of semi-natural habitats. Furthermore, farms with less semi-natural cover in the landscape and consequently, higher pest numbers, had lower yields than farms in less agriculturally dominated landscapes. Our study demonstrates the importance of landscape scale agricultural simplification in mediating the success of biological control programs and highlights the potential risks to native natural enemies in classical biological control programs against native insects. Our results represent an important contribution to an understanding of the landscape-mediated impacts on crop yield that will be essential to implementing effective policies that simultaneously conserve biodiversity and ecosystem services. © 2018 by the Ecological Society of America.

  14. Centella asiatica attenuates Aβ – induced neurodegenerative spine loss and dendritic simplification

    PubMed Central

    Gray, Nora E; Zweig, Jonathan A; Murchison, Charles; Caruso, Maya; Matthews, Donald G; Kawamoto, Colleen; Harris, Christopher J; Quinn, Joseph F; Soumyanath, Amala

    2017-01-01

    The medicinal plant Centella asiatica has long been used to improve memory and cognitive function. We have previously shown that a water extract from the plant (CAW) is neuroprotective against the deleterious cognitive effects of amyloid-β (Aβ) exposure in a mouse model of Alzheimer’s disease, and improves learning and memory in healthy aged mice as well. This study explores the physiological underpinnings of those effects by examining how CAW, as well as chemical compounds found within the extract, modulate synaptic health in Aβ-exposed neurons. Hippocampal neurons from amyloid precursor protein over-expressing Tg2576 mice and their wild-type (WT) littermates were used to investigate the effect of CAW and various compounds found within the extract on Aβ-induced dendritic simplification and synaptic loss. CAW enhanced arborization and spine densities in WT neurons and prevented the diminished outgrowth of dendrites and loss of spines caused by Aβ exposure in Tg2576 neurons. Triterpene compounds present in CAW were found to similarly improve arborization although they did not affect spine density. In contrast caffeoylquinic acid (CQA) compounds from CAW were able to modulate both of these endpoints, although there was specificity as to which CQAs mediated which effect. These data suggest that CAW, and several of the compounds found therein, can improve dendritic arborization and synaptic differentiation in the context of Aβ exposure which may underlie the cognitive improvement observed in response to the extract in vivo. Additionally, since CAW, and its constituent compounds, also improved these endpoints in WT neurons, these results may point to a broader therapeutic utility of the extract beyond Alzheimer’s disease. PMID:28279707

  15. Meaningful traits for grouping plant species across arid ecosystems.

    PubMed

    Bär Lamas, Marlene Ivonne; Carrera, A L; Bertiller, M B

    2016-05-01

    Grouping species may provide some degree of simplification to understand the ecological function of plants on key ecosystem processes. We asked whether groups of plant species based on morpho-chemical traits associated with plant persistence and stress/disturbance resistance reflect dominant plant growth forms in arid ecosystems. We selected twelve sites across an aridity gradient in northern Patagonia. At each site, we identified modal size plants of each dominant species and assessed specific leaf area (SLA), plant height, seed mass, N and soluble phenol concentration in green and senesced leaves at each plant. Plant species were grouped according with plant growth forms (perennial grasses, evergreen shrubs and deciduous shrubs) and plant morphological and/or chemical traits using cluster analysis. We calculated mean values of each plant trait for each species group and plant growth form. Plant growth forms significantly differed among them in most of the morpho-chemical traits. Evergreen shrubs were tall plants with the highest seed mass and soluble phenols in leaves, deciduous shrubs were also tall plants with high SLA and the highest N in leaves, and perennial grasses were short plants with high SLA and low concentration of N and soluble phenols in leaves. Grouping species by the combination of morpho-chemical traits yielded 4 groups in which species from one growth form prevailed. These species groups differed in soluble phenol concentration in senesced leaves and plant height. These traits were highly correlated. We concluded that (1) plant height is a relevant synthetic variable, (2) growth forms adequately summarize ecological strategies of species in arid ecosystems, and (3) the inclusion of plant morphological and chemical traits related to defenses against environmental stresses and herbivory enhanced the potential of species grouping, particularly within shrubby growth forms.

  16. Control of octopus arm extension by a peripheral motor program.

    PubMed

    Sumbre, G; Gutfreund, Y; Fiorito, G; Flash, T; Hochner, B

    2001-09-07

    For goal-directed arm movements, the nervous system generates a sequence of motor commands that bring the arm toward the target. Control of the octopus arm is especially complex because the arm can be moved in any direction, with a virtually infinite number of degrees of freedom. Here we show that arm extensions can be evoked mechanically or electrically in arms whose connection with the brain has been severed. These extensions show kinematic features that are almost identical to normal behavior, suggesting that the basic motor program for voluntary movement is embedded within the neural circuitry of the arm itself. Such peripheral motor programs represent considerable simplification in the motor control of this highly redundant appendage.

  17. Development of simplified ecosystem models for applications in Earth system studies: The Century experience

    NASA Technical Reports Server (NTRS)

    Parton, William J.; Ojima, Dennis S.; Schimel, David S.; Kittel, Timothy G. F.

    1992-01-01

    During the past decade, a growing need to conduct regional assessments of long-term trends of ecosystem behavior and the technology to meet this need have converged. The Century model is the product of research efforts initially intended to develop a general model of plant-soil ecosystem dynamics for the North American central grasslands. This model is now being used to simulate plant production, nutrient cycling, and soil organic matter dynamics for grassland, crop, forest, and shrub ecosystems in various regions of the world, including temperate and tropical ecosystems. This paper will focus on the philosophical approach used to develop the structure of Century. The steps included were model simplification, parameterization, and testing. In addition, the importance of acquiring regional data bases for model testing and the present regional application of Century in the Great Plains, which focus on regional ecosystem dynamics and the effect of altering environmental conditions, are discussed.

  18. Work Simplification

    ERIC Educational Resources Information Center

    Ross, Lynne

    1970-01-01

    Excerpts from a talk by Mrs. Ross at the 23rd annual convention of the American School Food Service Association in Detroit, August 5, 1969. A book on work simplification by Mrs. Ross will be available in June from the Iowa State University Press, Ames, Iowa. (Editor)

  19. 76 FR 27753 - Proposed Collection; Comment Request for Regulation Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-12

    ... collection requirements related to Simplification of Entity Classification Rules. DATES: Written comments....gov . SUPPLEMENTARY INFORMATION: Title: Simplification of Entity Classification Rules. OMB Number... partnerships for federal tax purposes. The election is made by filing Form 8832, Entity Classification Election...

  20. DNA G-segment bending is not the sole determinant of topology simplification by type II DNA topoisomerases.

    PubMed

    Thomson, Neil H; Santos, Sergio; Mitchenall, Lesley A; Stuchinskaya, Tanya; Taylor, James A; Maxwell, Anthony

    2014-08-21

    DNA topoisomerases control the topology of DNA. Type II topoisomerases exhibit topology simplification, whereby products of their reactions are simplified beyond that expected based on thermodynamic equilibrium. The molecular basis for this process is unknown, although DNA bending has been implicated. To investigate the role of bending in topology simplification, the DNA bend angles of four enzymes of different types (IIA and IIB) were measured using atomic force microscopy (AFM). The enzymes tested were Escherichia coli topo IV and yeast topo II (type IIA enzymes that exhibit topology simplification), and Methanosarcina mazei topo VI and Sulfolobus shibatae topo VI (type IIB enzymes, which do not). Bend angles were measured using the manual tangent method from topographical AFM images taken with a novel amplitude-modulated imaging mode: small amplitude small set-point (SASS), which optimises resolution for a given AFM tip size and minimises tip convolution with the sample. This gave improved accuracy and reliability and revealed that all 4 topoisomerases bend DNA by a similar amount: ~120° between the DNA entering and exiting the enzyme complex. These data indicate that DNA bending alone is insufficient to explain topology simplification and that the 'exit gate' may be an important determinant of this process.

  1. DNA G-segment bending is not the sole determinant of topology simplification by type II DNA topoisomerases

    NASA Astrophysics Data System (ADS)

    Thomson, Neil H.; Santos, Sergio; Mitchenall, Lesley A.; Stuchinskaya, Tanya; Taylor, James A.; Maxwell, Anthony

    2014-08-01

    DNA topoisomerases control the topology of DNA. Type II topoisomerases exhibit topology simplification, whereby products of their reactions are simplified beyond that expected based on thermodynamic equilibrium. The molecular basis for this process is unknown, although DNA bending has been implicated. To investigate the role of bending in topology simplification, the DNA bend angles of four enzymes of different types (IIA and IIB) were measured using atomic force microscopy (AFM). The enzymes tested were Escherichia coli topo IV and yeast topo II (type IIA enzymes that exhibit topology simplification), and Methanosarcina mazei topo VI and Sulfolobus shibatae topo VI (type IIB enzymes, which do not). Bend angles were measured using the manual tangent method from topographical AFM images taken with a novel amplitude-modulated imaging mode: small amplitude small set-point (SASS), which optimises resolution for a given AFM tip size and minimises tip convolution with the sample. This gave improved accuracy and reliability and revealed that all 4 topoisomerases bend DNA by a similar amount: ~120° between the DNA entering and exiting the enzyme complex. These data indicate that DNA bending alone is insufficient to explain topology simplification and that the `exit gate' may be an important determinant of this process.

  2. Simplification of the kinematic model of human movement

    NASA Astrophysics Data System (ADS)

    Dusza, Jacek J.; Wawrzyniak, Zbigniew M.; del Prado Martinez, David

    2013-10-01

    The paper presents a methods of simplification of the human gait model. The experimental data were obtained in the laboratory of the group SATI in the Electronics Engineering Department of the University of Valencia. As a result of the Mean Double Step (MDS) procedure, the human motion were described by a matrix containing the Cartesian coordinates of 26 markers placed on the human body recorded in the 100 time points. With these data it has been possible to develop an software application which performs a wide diversity of tasks like array simplification, mask calculation for the simplification, error calculation as well as tools for signals comparison and movement animation of the markers. Simplifications were made by the spectral analysis of signals and calculating the standard deviation of the differences between the signal and its approximation. Using this method the signals of displacement could be written as the time series limited to a small number of harmonic signals. This approach allows us for a high degree of data compression. The model presented in this work can be applied into the context of medical diagnostics or rehabilitation because for a given approximation error and a large number of harmonics may demonstrate some abnormalities (of orthopaedic symptoms) in the gait cycle analysis.

  3. MULTICOMPONENT THEORY OF BUOYANCY INSTABILITIES IN ASTROPHYSICAL PLASMA OBJECTS: THE CASE OF MAGNETIC FIELD PERPENDICULAR TO GRAVITY

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

    Nekrasov, Anatoly K.; Shadmehri, Mohsen, E-mail: anatoli.nekrassov@t-online.d, E-mail: mshadmehri@thphys.nuim.i

    2010-12-01

    We develop a general theory of buoyancy instabilities in the electron-ion plasma with the electron heat flux based not upon magnetohydrodynamic (MHD) equations, but using a multicomponent plasma approach in which the momentum equation is solved for each species. We investigate the geometry in which the background magnetic field is perpendicular to the gravity and stratification. General expressions for the perturbed velocities are given without any simplifications. Collisions between electrons and ions are taken into account in the momentum equations in a general form, permitting us to consider both weakly and strongly collisional objects. However, the electron heat flux ismore » assumed to be directed along the magnetic field, which implies a weakly collisional case. Using simplifications justified for an investigation of buoyancy instabilities with electron thermal flux, we derive simple dispersion relations for both collisionless and collisional cases for arbitrary directions of the wave vector. Our dispersion relations considerably differ from that obtained in the MHD framework and conditions of instability are similar to Schwarzschild's criterion. This difference is connected with simplified assumptions used in the MHD analysis of buoyancy instabilities and with the role of the longitudinal electric field perturbation which is not captured by the ideal MHD equations. The results obtained can be applied to clusters of galaxies and other astrophysical objects.« less

  4. The signed permutation group on Feynman graphs

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

    Purkart, Julian, E-mail: purkart@physik.hu-berlin.de

    2016-08-15

    The Feynman rules assign to every graph an integral which can be written as a function of a scaling parameter L. Assuming L for the process under consideration is very small, so that contributions to the renormalization group are small, we can expand the integral and only consider the lowest orders in the scaling. The aim of this article is to determine specific combinations of graphs in a scalar quantum field theory that lead to a remarkable simplification of the first non-trivial term in the perturbation series. It will be seen that the result is independent of the renormalization schememore » and the scattering angles. To achieve that goal we will utilize the parametric representation of scalar Feynman integrals as well as the Hopf algebraic structure of the Feynman graphs under consideration. Moreover, we will present a formula which reduces the effort of determining the first-order term in the perturbation series for the specific combination of graphs to a minimum.« less

  5. Toxic and feeding deterrent effects of native aquatic macrophytes on exotic grass carp (Ctenopharyngodon idella).

    PubMed

    Murphy, Joseph E; Beckmen, Kimberlee B; Johnson, Julie K; Cope, Rhian B; Lawmaster, Todd; Beasley, Val R

    2002-08-01

    Declines of amphibians have been attributed to many factors including habitat degradation. The introduction of grass carp (Ctenopharyngodon idella) as a biological agent for aquatic plant control in ponds and lakes managed narrowly for human recreation has likely contributed to amphibian declines through massive plant removal and associated habitat simplification and thus degradation. This research examined the interactions among grass carp and three Midwestern aquatic plants (Jussiaea repens, Ranunculus longirostris, and R. flabellaris) that may be of value in rehabilitation of habitats needed by amphibians. The feeding preference study found that C. idella avoided eating both J. repens and R. longirostris. Ranunculus species studied to date contain a vesicant toxin called ranunculin that is released upon mastication. The study that compared the effects of R. flabellaris, J. repens and a control food administered by tube feeding to C. idella found significant lesions only in the mucosal epithelium of the individuals exposed to R.flabellaris. The avoidance by C. idella of J. repens and R. longirostris in the feeding preference study, and the significant toxicity of R. flabellaris demonstrated by the dosing study, indicate these plants warrant further examination as to their potential effectiveness in aquatic amphibian habitat rehabilitation.

  6. Bat-Fruit Interactions Are More Specialized in Shaded-Coffee Plantations than in Tropical Mountain Cloud Forest Fragments

    PubMed Central

    Hernández-Montero, Jesús R.; Saldaña-Vázquez, Romeo A.; Galindo-González, Jorge; Sosa, Vinicio J.

    2015-01-01

    Forest disturbance causes specialization of plant-frugivore networks and jeopardizes mutualistic interactions through reduction of ecological redundancy. To evaluate how simplification of a forest into an agroecosystem affects plant-disperser mutualistic interactions, we compared bat-fruit interaction indexes of specialization in tropical montane cloud forest fragments (TMCF) and shaded-coffee plantations (SCP). Bat-fruit interactions were surveyed by collection of bat fecal samples. Bat-fruit interactions were more specialized in SCP (mean H2 ' = 0.55) compared to TMCF fragments (mean H2 ' = 0.27), and were negatively correlated to bat abundance in SCP (R = -0.35). The number of shared plant species was higher in the TMCF fragments (mean = 1) compared to the SCP (mean = 0.51) and this was positively correlated to the abundance of frugivorous bats (R= 0.79). The higher specialization in SCP could be explained by lower bat abundance and lower diet overlap among bats. Coffee farmers and conservation policy makers must increase the proportion of land assigned to TMCF within agroecosystem landscapes in order to conserve frugivorous bats and their invaluable seed dispersal service. PMID:25992550

  7. Bat-fruit interactions are more specialized in shaded-coffee plantations than in tropical mountain cloud forest fragments.

    PubMed

    Hernández-Montero, Jesús R; Saldaña-Vázquez, Romeo A; Galindo-González, Jorge; Sosa, Vinicio J

    2015-01-01

    Forest disturbance causes specialization of plant-frugivore networks and jeopardizes mutualistic interactions through reduction of ecological redundancy. To evaluate how simplification of a forest into an agroecosystem affects plant-disperser mutualistic interactions, we compared bat-fruit interaction indexes of specialization in tropical montane cloud forest fragments (TMCF) and shaded-coffee plantations (SCP). Bat-fruit interactions were surveyed by collection of bat fecal samples. Bat-fruit interactions were more specialized in SCP (mean H2 ' = 0.55) compared to TMCF fragments (mean H2 ' = 0.27), and were negatively correlated to bat abundance in SCP (R = -0.35). The number of shared plant species was higher in the TMCF fragments (mean = 1) compared to the SCP (mean = 0.51) and this was positively correlated to the abundance of frugivorous bats (R= 0.79). The higher specialization in SCP could be explained by lower bat abundance and lower diet overlap among bats. Coffee farmers and conservation policy makers must increase the proportion of land assigned to TMCF within agroecosystem landscapes in order to conserve frugivorous bats and their invaluable seed dispersal service.

  8. Treatment simplification in HIV-infected adults as a strategy to prevent toxicity, improve adherence, quality of life and decrease healthcare costs

    PubMed Central

    Nachega, Jean B; Mugavero, Michael J; Zeier, Michele; Vitória, Marco; Gallant, Joel E

    2011-01-01

    Since the advent of highly active antiretroviral therapy (HAART), the treatment of human immunodeficiency virus (HIV) infection has become more potent and better tolerated. While the current treatment regimens still have limitations, they are more effective, more convenient, and less toxic than regimens used in the early HAART era, and new agents, formulations and strategies continue to be developed. Simplification of therapy is an option for many patients currently being treated with antiretroviral therapy (ART). The main goals are to reduce pill burden, improve quality of life and enhance medication adherence, while minimizing short- and long-term toxicities, reducing the risk of virologic failure and maximizing cost-effectiveness. ART simplification strategies that are currently used or are under study include the use of once-daily regimens, less toxic drugs, fixed-dose coformulations and induction-maintenance approaches. Improved adherence and persistence have been observed with the adoption of some of these strategies. The role of regimen simplification has implications not only for individual patients, but also for health care policy. With increased interest in ART regimen simplification, it is critical to study not only implications for individual tolerability, toxicity, adherence, persistence and virologic efficacy, but also cost, scalability, and potential for dissemination and implementation, such that limited human and financial resources are optimally allocated for maximal efficiency, coverage and sustainability of global HIV/AIDS treatment. PMID:21845035

  9. Use of Syntactic Elaboration Techniques to Enhance Comprehensibility of EST Texts

    ERIC Educational Resources Information Center

    Rahimi, Mohammad Ali; Rezaei, Amir

    2011-01-01

    The current study examined differential effects of two pre-modification types, syntactic elaboration and syntactic simplification (at the level of syntax and irrespective of problematic lexis), on EST students' reading comprehension. The purpose was to see whether a priori syntactic elaborative adjustment, given its advantages over simplification,…

  10. 77 FR 66361 - Reserve Requirements of Depository Institutions: Reserves Simplification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-05

    ... simplifications related to the administration of reserve requirements: 1. Create a common two-week maintenance... earlier than it would implement the common maintenance period and the penalty-free band. The Board... effective July 12, 2012. The Board announced January 24, 2013, as the implementation date for the common two...

  11. Non-minimally coupled scalar field in Kantowski-Sachs model and symmetry analysis

    NASA Astrophysics Data System (ADS)

    Dutta, Sourav; Lakshmanan, Muthusamy; Chakraborty, Subenoy

    2018-06-01

    The paper deals with a non-minimally coupled scalar field in the background of homogeneous but anisotropic Kantowski-Sachs space-time model. The form of the coupling function of the scalar field with gravity and the potential function of the scalar field are not assumed phenomenologically, rather they are evaluated by imposing Noether symmetry to the Lagrangian of the present physical system. The physical system gets considerable mathematical simplification by a suitable transformation of the augmented variables (a , b , ϕ) →(u , v , w) and by the use of the conserved quantities due to the geometrical symmetry. Finally, cosmological solutions are evaluated and analyzed from the point of view of the present evolution of the Universe.

  12. Simplification of arboreal marsupial assemblages in response to increasing urbanization.

    PubMed

    Isaac, Bronwyn; White, John; Ierodiaconou, Daniel; Cooke, Raylene

    2014-01-01

    Arboreal marsupials play an essential role in ecosystem function including regulating insect and plant populations, facilitating pollen and seed dispersal and acting as a prey source for higher-order carnivores in Australian environments. Primarily, research has focused on their biology, ecology and response to disturbance in forested and urban environments. We used presence-only species distribution modelling to understand the relationship between occurrences of arboreal marsupials and eco-geographical variables, and to infer habitat suitability across an urban gradient. We used post-proportional analysis to determine whether increasing urbanization affected potential habitat for arboreal marsupials. The key eco-geographical variables that influenced disturbance intolerant species and those with moderate tolerance to disturbance were natural features such as tree cover and proximity to rivers and to riparian vegetation, whereas variables for disturbance tolerant species were anthropogenic-based (e.g., road density) but also included some natural characteristics such as proximity to riparian vegetation, elevation and tree cover. Arboreal marsupial diversity was subject to substantial change along the gradient, with potential habitat for disturbance-tolerant marsupials distributed across the complete gradient and potential habitat for less tolerant species being restricted to the natural portion of the gradient. This resulted in highly-urbanized environments being inhabited by a few generalist arboreal marsupial species. Increasing urbanization therefore leads to functional simplification of arboreal marsupial assemblages, thus impacting on the ecosystem services they provide.

  13. Simplification of Arboreal Marsupial Assemblages in Response to Increasing Urbanization

    PubMed Central

    Isaac, Bronwyn; White, John; Ierodiaconou, Daniel; Cooke, Raylene

    2014-01-01

    Arboreal marsupials play an essential role in ecosystem function including regulating insect and plant populations, facilitating pollen and seed dispersal and acting as a prey source for higher-order carnivores in Australian environments. Primarily, research has focused on their biology, ecology and response to disturbance in forested and urban environments. We used presence-only species distribution modelling to understand the relationship between occurrences of arboreal marsupials and eco-geographical variables, and to infer habitat suitability across an urban gradient. We used post-proportional analysis to determine whether increasing urbanization affected potential habitat for arboreal marsupials. The key eco-geographical variables that influenced disturbance intolerant species and those with moderate tolerance to disturbance were natural features such as tree cover and proximity to rivers and to riparian vegetation, whereas variables for disturbance tolerant species were anthropogenic-based (e.g., road density) but also included some natural characteristics such as proximity to riparian vegetation, elevation and tree cover. Arboreal marsupial diversity was subject to substantial change along the gradient, with potential habitat for disturbance-tolerant marsupials distributed across the complete gradient and potential habitat for less tolerant species being restricted to the natural portion of the gradient. This resulted in highly-urbanized environments being inhabited by a few generalist arboreal marsupial species. Increasing urbanization therefore leads to functional simplification of arboreal marsupial assemblages, thus impacting on the ecosystem services they provide. PMID:24608165

  14. Crop-noncrop spillover: arable fields affect trophic interactions on wild plants in surrounding habitats.

    PubMed

    Gladbach, David J; Holzschuh, Andrea; Scherber, Christoph; Thies, Carsten; Dormann, Carsten F; Tscharntke, Teja

    2011-06-01

    Ecosystem processes in agricultural landscapes are often triggered by resource availability in crop and noncrop habitats. We investigated how oilseed rape (OSR; Brassica napus, Brassicaceae) affects noncrop plants in managed systems and semi-natural habitat, using trophic interactions among wild mustard (Sinapis arvensis, Brassicaceae), rape pollen beetles (Meligethes aeneus, Nitidulidae) and their parasitoids (Tersilochus heterocerus, Ichneumonidae). We exposed wild mustard as phytometer plants in two cropland habitat types (wheat field, field margin) and three noncrop habitat types (fallow, grassland, wood margin) across eight landscapes along a gradient from simple to complex (quantified as % arable land). Both landscape and local factors affected the abundance of rape pollen beetles and parasitoids. Rape pollen beetle infestation and parasitism rates on these plants were lower in noncrop habitats and higher in wheat fields and field margins, whereas beetles and parasitoids responded differently to landscape scale parameters. We found the hypothesized spillover from OSR crop onto wild plants in surrounding habitats only for parasitoids, but not for pollen beetles. Parasitism rates were not related to landscape simplification, but benefited from increasing proportions of OSR. In contrast, rape pollen beetles benefited from simple landscape structures, presumably due to multi-annual population build-ups resulting from long-term OSR planting (as part of the crop rotation). In conclusion, we showed that spillover from cropland affects parasitism rates on related wild plants outside cropland, which has not been shown so far, but can be expected to be a widespread effect shaping noncrop food webs.

  15. Aspects of a Theory of Simplification, Debugging, and Coaching.

    ERIC Educational Resources Information Center

    Fischer, Gerhard; And Others

    This paper analyses new methods of teaching skiing in terms of a computational paradigm for learning called increasingly complex microworlds (ICM). Examining the factors that underlie the dramatic enhancement of the learning of skiing led to the focus on the processes of simplification, debugging, and coaching. These three processes are studied in…

  16. Legal Language: What Is It and What Can We Do About It?

    ERIC Educational Resources Information Center

    Charrow, Veda R.; Crandall, Jo Ann

    The simplification of legal language is required by President Carter's Executive Order requiring "clear and simple English" in government regulations. A major problem in the simplification process is the absence of any adequate description or classification of legal language. This paper defines some specific features of legal language,…

  17. Between-Word Simplification Patterns in the Continuous Speech of Children with Speech Sound Disorders

    ERIC Educational Resources Information Center

    Klein, Harriet B.; Liu-Shea, May

    2009-01-01

    Purpose: This study was designed to identify and describe between-word simplification patterns in the continuous speech of children with speech sound disorders. It was hypothesized that word combinations would reveal phonological changes that were unobserved with single words, possibly accounting for discrepancies between the intelligibility of…

  18. Elements of complexity in subsurface modeling, exemplified with three case studies

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

    Freedman, Vicky L.; Truex, Michael J.; Rockhold, Mark

    2017-04-03

    There are complexity elements to consider when applying subsurface flow and transport models to support environmental analyses. Modelers balance the benefits and costs of modeling along the spectrum of complexity, taking into account the attributes of more simple models (e.g., lower cost, faster execution, easier to explain, less mechanistic) and the attributes of more complex models (higher cost, slower execution, harder to explain, more mechanistic and technically defensible). In this paper, modeling complexity is examined with respect to considering this balance. The discussion of modeling complexity is organized into three primary elements: 1) modeling approach, 2) description of process, andmore » 3) description of heterogeneity. Three examples are used to examine these complexity elements. Two of the examples use simulations generated from a complex model to develop simpler models for efficient use in model applications. The first example is designed to support performance evaluation of soil vapor extraction remediation in terms of groundwater protection. The second example investigates the importance of simulating different categories of geochemical reactions for carbon sequestration and selecting appropriate simplifications for use in evaluating sequestration scenarios. In the third example, the modeling history for a uranium-contaminated site demonstrates that conservative parameter estimates were inadequate surrogates for complex, critical processes and there is discussion on the selection of more appropriate model complexity for this application. All three examples highlight how complexity considerations are essential to create scientifically defensible models that achieve a balance between model simplification and complexity.« less

  19. Science Language Accommodation in Elementary School Read-Alouds

    NASA Astrophysics Data System (ADS)

    Glass, Rory; Oliveira, Alandeom W.

    2014-03-01

    This study examines the pedagogical functions of accommodation (i.e. provision of simplified science speech) in science read-aloud sessions facilitated by five elementary teachers. We conceive of read-alouds as communicative events wherein teachers, faced with the task of orally delivering a science text of relatively high linguistic complexity, open up an alternate channel of communication, namely oral discussion. By doing so, teachers grant students access to a simplified linguistic input, a strategy designed to promote student comprehension of the textual contents of children's science books. It was found that nearly half (46%) of the read-aloud time was allotted to discussions with an increased percentage of less sophisticated words and reduced use of more sophisticated vocabulary than found in the books through communicative strategies such as simplified rewording, simplified definition, and simplified questioning. Further, aloud reading of more linguistically complex books required longer periods of discussion and an increased degree of teacher oral input and accommodation. We also found evidence of reversed simplification (i.e. sophistication), leading to student uptake of scientific language. The main significance of this study is that it reveals that teacher talk serves two often competing pedagogical functions (accessible communication of scientific information to students and promotion of student acquisition of the specialized language of science). It also underscores the importance of giving analytical consideration to the simplification-sophistication dimension of science classroom discourse as well as the potential of computer-based analysis of classroom discourse to inform science teaching.

  20. Elements of complexity in subsurface modeling, exemplified with three case studies

    NASA Astrophysics Data System (ADS)

    Freedman, Vicky L.; Truex, Michael J.; Rockhold, Mark L.; Bacon, Diana H.; Freshley, Mark D.; Wellman, Dawn M.

    2017-09-01

    There are complexity elements to consider when applying subsurface flow and transport models to support environmental analyses. Modelers balance the benefits and costs of modeling along the spectrum of complexity, taking into account the attributes of more simple models (e.g., lower cost, faster execution, easier to explain, less mechanistic) and the attributes of more complex models (higher cost, slower execution, harder to explain, more mechanistic and technically defensible). In this report, modeling complexity is examined with respect to considering this balance. The discussion of modeling complexity is organized into three primary elements: (1) modeling approach, (2) description of process, and (3) description of heterogeneity. Three examples are used to examine these complexity elements. Two of the examples use simulations generated from a complex model to develop simpler models for efficient use in model applications. The first example is designed to support performance evaluation of soil-vapor-extraction remediation in terms of groundwater protection. The second example investigates the importance of simulating different categories of geochemical reactions for carbon sequestration and selecting appropriate simplifications for use in evaluating sequestration scenarios. In the third example, the modeling history for a uranium-contaminated site demonstrates that conservative parameter estimates were inadequate surrogates for complex, critical processes and there is discussion on the selection of more appropriate model complexity for this application. All three examples highlight how complexity considerations are essential to create scientifically defensible models that achieve a balance between model simplification and complexity.

  1. Characteristic operator functions for quantum input-plant-output models and coherent control

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

    Gough, John E.

    We introduce the characteristic operator as the generalization of the usual concept of a transfer function of linear input-plant-output systems to arbitrary quantum nonlinear Markovian input-output models. This is intended as a tool in the characterization of quantum feedback control systems that fits in with the general theory of networks. The definition exploits the linearity of noise differentials in both the plant Heisenberg equations of motion and the differential form of the input-output relations. Mathematically, the characteristic operator is a matrix of dimension equal to the number of outputs times the number of inputs (which must coincide), but with entriesmore » that are operators of the plant system. In this sense, the characteristic operator retains details of the effective plant dynamical structure and is an essentially quantum object. We illustrate the relevance to model reduction and simplification definition by showing that the convergence of the characteristic operator in adiabatic elimination limit models requires the same conditions and assumptions appearing in the work on limit quantum stochastic differential theorems of Bouten and Silberfarb [Commun. Math. Phys. 283, 491-505 (2008)]. This approach also shows in a natural way that the limit coefficients of the quantum stochastic differential equations in adiabatic elimination problems arise algebraically as Schur complements and amounts to a model reduction where the fast degrees of freedom are decoupled from the slow ones and eliminated.« less

  2. Encountering Productive Forms of Complexity in Learning Modern Physics

    ERIC Educational Resources Information Center

    Levrini, Olivia; Fantini, Paola

    2013-01-01

    This paper aims at supporting the claim that some forms of hyper-simplification, by making physics seem easy, are at risk of dangerously distorting the content as well as the process of learning physics. The paper presents examples of dangerous simplifications in the teaching of quantum physics. Then, examples of productive forms of complexity are…

  3. 76 FR 40457 - Administrative Simplification: Adoption of Operating Rules for Eligibility for a Health Plan and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-08

    ... Plan and Health Care Claim Status Transactions; Interim Final Rule #0;#0;Federal Register / Vol. 76, No... Simplification: Adoption of Operating Rules for Eligibility for a Health Plan and Health Care Claim Status... rules for the health care industry and directed the Secretary of Health and Human Services to ``adopt a...

  4. Simplification of irreversible Markov chains by removal of states with fast leaving rates.

    PubMed

    Jia, Chen

    2016-07-07

    In the recent work of Ullah et al. (2012a), the authors developed an effective method to simplify reversible Markov chains by removal of states with low equilibrium occupancies. In this paper, we extend this result to irreversible Markov chains. We show that an irreversible chain can be simplified by removal of states with fast leaving rates. Moreover, we reveal that the irreversibility of the chain will always decrease after model simplification. This suggests that although model simplification can retain almost all the dynamic information of the chain, it will lose some thermodynamic information as a trade-off. Examples from biology are also given to illustrate the main results of this paper. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Deconstructing the simplification of jury instructions: How simplifying the features of complexity affects jurors' application of instructions.

    PubMed

    Baguley, Chantelle M; McKimmie, Blake M; Masser, Barbara M

    2017-06-01

    Research consistently shows that techniques currently used to simplify jury instructions do not always improve mock jurors' comprehension. If improvements are observed, these are limited and overall comprehension remains low. It is unclear, however, why this occurs. It is possible that current simplification techniques do not effectively simplify the features of complexity, present in standardized instructions, which have the greatest effect on jurors' comprehension. It is not yet known, however, how much each feature of complexity individually affects jurors' comprehension. To investigate this, the authors used existing data from published empirical studies to examine how simplifying each feature of complexity affects mock jurors' application of instructions, as jurors can only apply instructions to the extent they understand them. The results suggest that reducing the conceptual complexity and proportion of supplementary information was associated with increased application of the instructions; however, reducing both the linguistic complexity and amount of information, and providing the instructions in a written format was not. In addition, results showed an unexpected adverse effect of simplification-reducing the amount of information was associated with an increase in the punitiveness of mock jurors' verdicts, independently of the instruction content. Together, these results suggest a need to make jury instructions comprehensible, highlight the key principles in the decision-process, and identify a way to eliminate the negative effect of reducing the amount of information. Addressing these needs is essential for developing a simplification technique that maximizes jurors' comprehension and application of instructions, while minimizing the previously overlooked negative effects of simplification. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  6. Analysis of Slug Tests in Formations of High Hydraulic Conductivity

    USGS Publications Warehouse

    Butler, J.J.; Garnett, E.J.; Healey, J.M.

    2003-01-01

    A new procedure is presented for the analysis of slug tests performed in partially penetrating wells in formations of high hydraulic conductivity. This approach is a simple, spreadsheet-based implementation of existing models that can be used for analysis of tests from confined or unconfined aquifers. Field examples of tests exhibiting oscillatory and nonoscillatory behavior are used to illustrate the procedure and to compare results with estimates obtained using alternative approaches. The procedure is considerably simpler than recently proposed methods for this hydrogeologic setting. Although the simplifications required by the approach can introduce error into hydraulic-conductivity estimates, this additional error becomes negligible when appropriate measures are taken in the field. These measures are summarized in a set of practical field guidelines for slug tests in highly permeable aquifers.

  7. Evaluation of RANS and LES models for Natural Convection in High-Aspect-Ratio Parallel Plate Channels

    NASA Astrophysics Data System (ADS)

    Fradeneck, Austen; Kimber, Mark

    2017-11-01

    The present study evaluates the effectiveness of current RANS and LES models in simulating natural convection in high-aspect ratio parallel plate channels. The geometry under consideration is based on a simplification of the coolant and bypass channels in the very high-temperature gas reactor (VHTR). Two thermal conditions are considered, asymmetric and symmetric wall heating with an applied heat flux to match Rayleigh numbers experienced in the VHTR during a loss of flow accident (LOFA). RANS models are compared to analogous high-fidelity LES simulations. Preliminary results demonstrate the efficacy of the low-Reynolds number k- ɛ formulations and their enhancement to the standard form and Reynolds stress transport model in terms of calculating the turbulence production due to buoyancy and overall mean flow variables.

  8. Analysis of slug tests in formations of high hydraulic conductivity.

    PubMed

    Butler, James J; Garnett, Elizabeth J; Healey, John M

    2003-01-01

    A new procedure is presented for the analysis of slug tests performed in partially penetrating wells in formations of high hydraulic conductivity. This approach is a simple, spreadsheet-based implementation of existing models that can be used for analysis of tests from confined or unconfined aquifers. Field examples of tests exhibiting oscillatory and nonoscillatory behavior are used to illustrate the procedure and to compare results with estimates obtained using alternative approaches. The procedure is considerably simpler than recently proposed methods for this hydrogeologic setting. Although the simplifications required by the approach can introduce error into hydraulic-conductivity estimates, this additional error becomes negligible when appropriate measures are taken in the field. These measures are summarized in a set of practical field guidelines for slug tests in highly permeable aquifers.

  9. New Strategies in Radiation Therapy: Exploiting the Full Potential of Protons

    PubMed Central

    Mohan, Radhe; Mahajan, Anita; Minsky, Bruce D.

    2013-01-01

    Protons provide significant dosimetric advantages compared with photons due to their unique depth-dose distribution characteristics. However, they are more sensitive to the effects of intra- and inter-treatment fraction anatomic variations and uncertainties in treatment setup. Furthermore, in the current practice of proton therapy, the biological effectiveness of protons relative to photons is assumed to have a generic fixed value of 1.1. However, this is a simplification, and it is likely higher in different portions of the proton beam. Current clinical practice and trials have not fully exploited the unique physical and biological properties of protons. Intensity-modulated proton therapy, with its ability to manipulate energies (in addition to intensities), provides an entirely new dimension, which, with ongoing research, has considerable potential to increase the therapeutic ratio. PMID:24077353

  10. New strategies in radiation therapy: exploiting the full potential of protons.

    PubMed

    Mohan, Radhe; Mahajan, Anita; Minsky, Bruce D

    2013-12-01

    Protons provide significant dosimetric advantages compared with photons because of their unique depth-dose distribution characteristics. However, they are more sensitive to the effects of intra- and intertreatment fraction anatomic variations and uncertainties in treatment setup. Furthermore, in the current practice of proton therapy, the biologic effectiveness of protons relative to photons is assumed to have a generic fixed value of 1.1. However, this is a simplification, and it is likely higher in different portions of the proton beam. Current clinical practice and trials have not fully exploited the unique physical and biologic properties of protons. Intensity-modulated proton therapy, with its ability to manipulate energies (in addition to intensities), provides an entirely new dimension, which, with ongoing research, has considerable potential to increase the therapeutic ratio. ©2013 AACR.

  11. Loss of functional diversity and network modularity in introduced plant–fungal symbioses

    PubMed Central

    Cooper, Jerry A.; Bufford, Jennifer L.; Hulme, Philip E.; Bates, Scott T.

    2017-01-01

    The introduction of alien plants into a new range can result in the loss of co-evolved symbiotic organisms, such as mycorrhizal fungi, that are essential for normal plant physiological functions. Prior studies of mycorrhizal associations in alien plants have tended to focus on individual plant species on a case-by-case basis. This approach limits broad scale understanding of functional shifts and changes in interaction network structure that may occur following introduction. Here we use two extensive datasets of plant–fungal interactions derived from fungal sporocarp observations and recorded plant hosts in two island archipelago nations: New Zealand (NZ) and the United Kingdom (UK). We found that the NZ dataset shows a lower functional diversity of fungal hyphal foraging strategies in mycorrhiza of alien when compared with native trees. Across species this resulted in fungal foraging strategies associated with alien trees being much more variable in functional composition compared with native trees, which had a strikingly similar functional composition. The UK data showed no functional difference in fungal associates of alien and native plant genera. Notwithstanding this, both the NZ and UK data showed a substantial difference in interaction network structure of alien trees compared with native trees. In both cases, fungal associates of native trees showed strong modularity, while fungal associates of alien trees generally integrated into a single large module. The results suggest a lower functional diversity (in one dataset) and a simplification of network structure (in both) as a result of introduction, potentially driven by either limited symbiont co-introductions or disruption of habitat as a driver of specificity due to nursery conditions, planting, or plant edaphic-niche expansion. Recognizing these shifts in function and network structure has important implications for plant invasions and facilitation of secondary invasions via shared mutualist populations. PMID:28039116

  12. Financial Aid Administrators' Views on Simplifying Financial Aid: NASFAA's 2008 Financial Aid Simplification Survey Report

    ERIC Educational Resources Information Center

    National Association of Student Financial Aid Administrators (NJ1), 2008

    2008-01-01

    Despite a decade of simplification efforts, students and families are often still baffled by the student aid process and cringe at the sight of financial aid application forms. Contrary to its purpose of helping students to access college, the student aid application process causes families frustration and confusion that has been cited as an…

  13. Streaming simplification of tetrahedral meshes.

    PubMed

    Vo, Huy T; Callahan, Steven P; Lindstrom, Peter; Pascucci, Valerio; Silva, Cláudio T

    2007-01-01

    Unstructured tetrahedral meshes are commonly used in scientific computing to represent scalar, vector, and tensor fields in three dimensions. Visualization of these meshes can be difficult to perform interactively due to their size and complexity. By reducing the size of the data, we can accomplish real-time visualization necessary for scientific analysis. We propose a two-step approach for streaming simplification of large tetrahedral meshes. Our algorithm arranges the data on disk in a streaming, I/O-efficient format that allows coherent access to the tetrahedral cells. A quadric-based simplification is sequentially performed on small portions of the mesh in-core. Our output is a coherent streaming mesh which facilitates future processing. Our technique is fast, produces high quality approximations, and operates out-of-core to process meshes too large for main memory.

  14. Trophic redundancy reduces vulnerability to extinction cascades

    PubMed Central

    Sanders, Dirk; Thébault, Elisa; Kehoe, Rachel; Frank van Veen, F. J.

    2018-01-01

    Current species extinction rates are at unprecedentedly high levels. While human activities can be the direct cause of some extinctions, it is becoming increasingly clear that species extinctions themselves can be the cause of further extinctions, since species affect each other through the network of ecological interactions among them. There is concern that the simplification of ecosystems, due to the loss of species and ecological interactions, increases their vulnerability to such secondary extinctions. It is predicted that more complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Here, we demonstrate in a field experiment with replicated plant-insect communities, that the probability of secondary extinctions is indeed smaller in food webs that include trophic redundancy. Harvesting one species of parasitoid wasp led to secondary extinctions of other, indirectly linked, species at the same trophic level. This effect was markedly stronger in simple communities than for the same species within a more complex food web. We show that this is due to functional redundancy in the more complex food webs and confirm this mechanism with a food web simulation model by highlighting the importance of the presence and strength of trophic links providing redundancy to those links that were lost. Our results demonstrate that biodiversity loss, leading to a reduction in redundant interactions, can increase the vulnerability of ecosystems to secondary extinctions, which, when they occur, can then lead to further simplification and run-away extinction cascades. PMID:29467292

  15. View-Dependent Simplification of Arbitrary Polygonal Environments

    DTIC Science & Technology

    2006-01-01

    of backfacing nodes are not rendered [ Kumar 96]. 4.3 Triangle-Budget Simplification The screenspace error threshold and silhouette test allow the user...Greg Turk, and Dinesh Manocha for their invaluable guidance and support throughout this project. Funding for this work was provided by DARPA...Proceedings Visualization 95 , IEEE Computer Society Press (Atlanta, GA), 1995, pp. 296-303. [ Kumar 96] Kumar , Subodh, D. Manocha, W. Garrett, M. Lin

  16. Perceptual Recovery from Consonant-Cluster Simplification in Korean Using Language-Specific Phonological Knowledge

    ERIC Educational Resources Information Center

    Cho, Taehong; McQueen, James M.

    2011-01-01

    Two experiments examined whether perceptual recovery from Korean consonant-cluster simplification is based on language-specific phonological knowledge. In tri-consonantal C1C2C3 sequences such as /lkt/ and /lpt/ in Seoul Korean, either C1 or C2 can be completely deleted. Seoul Koreans monitored for C2 targets (/p/ or /k/, deleted or preserved) in…

  17. The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment. NBER Working Paper No. 15361

    ERIC Educational Resources Information Center

    Bettinger, Eric P.; Long, Bridget Terry; Oreopoulos, Philip; Sanbonmatsu, Lisa

    2009-01-01

    Growing concerns about low awareness and take-up rates for government support programs like college financial aid have spurred calls to simplify the application process and enhance visibility. This project examines the effects of two experimental treatments designed to test of the importance of simplification and information using a random…

  18. WWC Quick Review of the Report "The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment" Revised

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2010

    2010-01-01

    This paper presents an updated WWC (What Works Clearinghouse) Quick Review of the report "The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment". The study examined whether assistance in filling out the Free Application for Federal Student Aid (FAFSA) increases the likelihood of…

  19. WWC Quick Review of the Report "The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment"

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2010

    2010-01-01

    This paper presents a WWC (What Works Clearinghouse) Quick Review of the report "The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment". The study examined whether assistance in filling out the Free Application for Federal Student Aid (FAFSA) increases the likelihood of filing…

  20. Effects of simplifying fracture network representation on inert chemical migration in fracture-controlled aquifers

    USGS Publications Warehouse

    Wellman, Tristan; Shapiro, Allen M.; Hill, Mary C.

    2009-01-01

    While it is widely recognized that highly permeable 'large-scale' fractures dominate chemical migration in many fractured aquifers, recent studies suggest that the pervasive 'small-scale' fracturing once considered of less significance can be equally important for characterizing the spatial extent and residence time associated with transport processes. A detailed examination of chemical migration through fracture-controlled aquifers is used to advance this conceptual understanding. The influence of fracture structure is evaluated by quantifying the effects to transport caused by a systematic removal of fractures from three-dimensional discrete fracture models whose attributes are derived from geologic and hydrologic conditions at multiple field sites. Results indicate that the effects to transport caused by network simplification are sensitive to the fracture network characteristics, degree of network simplification, and plume travel distance, but primarily in an indirect sense since correlation to individual attributes is limited. Transport processes can be 'enhanced' or 'restricted' from network simplification meaning that the elimination of fractures may increase or decrease mass migration, mean travel time, dispersion, and tailing of the concentration plume. The results demonstrate why, for instance, chemical migration may not follow the classic advection-dispersion equation where dispersion approximates the effect of the ignored geologic structure as a strictly additive process to the mean flow. The analyses further reveal that the prediction error caused by fracture network simplification is reduced by at least 50% using the median estimate from an ensemble of simplified fracture network models, and that the error from network simplification is at least 70% less than the stochastic variability from multiple realizations. Copyright 2009 by the American Geophysical Union.

  1. Theories of Simplification and Scaling of Spatially Distributed Processes. Chapter 12

    NASA Technical Reports Server (NTRS)

    Levin, Simon A.; Pacala, Stephen W.

    1997-01-01

    The problem of scaling is at the heart of ecological theory, the essence of understanding and of the development of a predictive capability. The description of any system depends on the spatial, temporal, and organizational perspective chosen; hence it is essential to understand not only how patterns and dynamics vary with scale, but also how patterns at one scale are manifestations of processes operating at other scales. Evolution has shaped the characteristics of species in ways that result in scale displacement: Each species experiences the environment at its own unique set of spatial and temporal scales and interfaces the biota through unique assemblages of phenotypes. In this way, coexistence becomes possible, and biodiversity is enhanced. By averaging over space, time, and biological interactions, a genotype filters variation at fine scales and selects the arena in which it will face the vicissitudes of nature. Variation at finer scales is then noise, of minor importance to the survival and dynamics of the species, and consequently of minor importance in any attempt at description. In attempting to model ecological interactions in space, contributors throughout this book have struggled with a trade-off between simplification and "realistic" complexity and detail. Although the challenge of simplification is widely recognized in ecology, less appreciated is the intertwining of scaling questions and scaling laws with the process of simplification. In the context of this chapter simplification will in general mean the use of spatial or ensemble means and low-order moments to capture more detailed interactions by integrating over given areas. In this way, one can derive descriptions of the system at different spatial scales, which provides the essentials for the extraction of scaling laws by examination of how system properties vary with scale.

  2. Local, smooth, and consistent Jacobi set simplification

    DOE PAGES

    Bhatia, Harsh; Wang, Bei; Norgard, Gregory; ...

    2014-10-31

    The relation between two Morse functions defined on a smooth, compact, and orientable 2-manifold can be studied in terms of their Jacobi set. The Jacobi set contains points in the domain where the gradients of the two functions are aligned. Both the Jacobi set itself as well as the segmentation of the domain it induces, have shown to be useful in various applications. In practice, unfortunately, functions often contain noise and discretization artifacts, causing their Jacobi set to become unmanageably large and complex. Although there exist techniques to simplify Jacobi sets, they are unsuitable for most applications as they lackmore » fine-grained control over the process, and heavily restrict the type of simplifications possible. In this paper, we introduce a new framework that generalizes critical point cancellations in scalar functions to Jacobi set in two dimensions. We present a new interpretation of Jacobi set simplification based on the perspective of domain segmentation. Generalizing the cancellation of critical points from scalar functions to Jacobi sets, we focus on simplifications that can be realized by smooth approximations of the corresponding functions, and show how these cancellations imply simultaneous simplification of contiguous subsets of the Jacobi set. Using these extended cancellations as atomic operations, we introduce an algorithm to successively cancel subsets of the Jacobi set with minimal modifications to some user-defined metric. We show that for simply connected domains, our algorithm reduces a given Jacobi set to its minimal configuration, that is, one with no birth–death points (a birth–death point is a specific type of singularity within the Jacobi set where the level sets of the two functions and the Jacobi set have a common normal direction).« less

  3. The non-independence discussion about cycle structure in the computer language: the final simplification of computer language in the structural design

    NASA Astrophysics Data System (ADS)

    Yang, Peilu

    2013-03-01

    In the first place, the article discusses the theory, content, development, and questions about structured programming design. The further extension on this basement provides the cycle structure in computer language is the sequence structure, branch structure, and the cycle structure with independence. Through the deeply research by the writer, we find the non-independence and reach the final simplification about the computer language design. In the first, the writer provides the language structure of linear structure (I structure) and curvilinear structure (Y structure). This makes the computer language has high proficiency with simplification during the program exploration. The research in this article is corresponding with the widely used dualistic structure in the computer field. Moreover, it is greatly promote the evolution of computer language.

  4. BioSimplify: an open source sentence simplification engine to improve recall in automatic biomedical information extraction.

    PubMed

    Jonnalagadda, Siddhartha; Gonzalez, Graciela

    2010-11-13

    BioSimplify is an open source tool written in Java that introduces and facilitates the use of a novel model for sentence simplification tuned for automatic discourse analysis and information extraction (as opposed to sentence simplification for improving human readability). The model is based on a "shot-gun" approach that produces many different (simpler) versions of the original sentence by combining variants of its constituent elements. This tool is optimized for processing biomedical scientific literature such as the abstracts indexed in PubMed. We tested our tool on its impact to the task of PPI extraction and it improved the f-score of the PPI tool by around 7%, with an improvement in recall of around 20%. The BioSimplify tool and test corpus can be downloaded from https://biosimplify.sourceforge.net.

  5. Comparison of DNA decatenation by Escherichia coli topoisomerase IV and topoisomerase III: implications for non-equilibrium topology simplification

    PubMed Central

    Seol, Yeonee; Hardin, Ashley H.; Strub, Marie-Paule; Charvin, Gilles; Neuman, Keir C.

    2013-01-01

    Type II topoisomerases are essential enzymes that regulate DNA topology through a strand-passage mechanism. Some type II topoisomerases relax supercoils, unknot and decatenate DNA to below thermodynamic equilibrium. Several models of this non-equilibrium topology simplification phenomenon have been proposed. The kinetic proofreading (KPR) model postulates that strand passage requires a DNA-bound topoisomerase to collide twice in rapid succession with a second DNA segment, implying a quadratic relationship between DNA collision frequency and relaxation rate. To test this model, we used a single-molecule assay to measure the unlinking rate as a function of DNA collision frequency for Escherichia coli topoisomerase IV (topo IV) that displays efficient non-equilibrium topology simplification activity, and for E. coli topoisomerase III (topo III), a type IA topoisomerase that unlinks and unknots DNA to equilibrium levels. Contrary to the predictions of the KPR model, topo IV and topo III unlinking rates were linearly related to the DNA collision frequency. Furthermore, topo III exhibited decatenation activity comparable with that of topo IV, supporting proposed roles for topo III in DNA segregation. This study enables us to rule out the KPR model for non-equilibrium topology simplification. More generally, we establish an experimental approach to systematically control DNA collision frequency. PMID:23460205

  6. Fuel cell power plant economic and operational considerations

    NASA Technical Reports Server (NTRS)

    Lance, J. R.

    1984-01-01

    Fuel cell power plants intended for electric utility and cogeneration applications are now in the design and construction stage. This paper describes economic and operational considerations being used in the development and design of plants utilizing air cooled phosphoric acid fuel cells. Fuel cell power plants have some unique characteristics relative to other types of power plants. As a result it was necessary to develop specific definitions of the fuel cell power plant characteristics in order to perform cost of electricity calculations. This paper describes these characteristics and describes the economic analyses used in the Westinghouse fuel cell power plant program.

  7. Brain Mechanisms for Making, Breaking, and Changing Rules

    NASA Astrophysics Data System (ADS)

    Levine, Daniel S.

    Individuals differ widely, and the same person varies over time, in their tendency to seek maximum information versus their tendency to follow the simplest heuristics. Neuroimaging studies suggest which brain regions might mediate the balance between knowledge maximization and heuristic simplification. The amygdala is more activated in individuals who use primitive heuristics, whereas two areas of the frontal lobes are more activated in individuals with a strong knowledge drive: one area involved in detecting risk or conflict, and another involved in choosing task-appropriate responses. Both of these motivations have engineering uses. There is benefit to understanding a situation at a high enough level to respond in a flexible manner when the context is complex and time allows detailed consideration. Yet simplifying heuristics can yield benefits when the context is routine or when time is limited.

  8. Amplitudes for multiphoton quantum processes in linear optics

    NASA Astrophysics Data System (ADS)

    Urías, Jesús

    2011-07-01

    The prominent role that linear optical networks have acquired in the engineering of photon states calls for physically intuitive and automatic methods to compute the probability amplitudes for the multiphoton quantum processes occurring in linear optics. A version of Wick's theorem for the expectation value, on any vector state, of products of linear operators, in general, is proved. We use it to extract the combinatorics of any multiphoton quantum processes in linear optics. The result is presented as a concise rule to write down directly explicit formulae for the probability amplitude of any multiphoton process in linear optics. The rule achieves a considerable simplification and provides an intuitive physical insight about quantum multiphoton processes. The methodology is applied to the generation of high-photon-number entangled states by interferometrically mixing coherent light with spontaneously down-converted light.

  9. Simplified design of thin-film polarizing beam splitter using embedded symmetric trilayer stack.

    PubMed

    Azzam, R M A

    2011-07-01

    An analytically tractable design procedure is presented for a polarizing beam splitter (PBS) that uses frustrated total internal reflection and optical tunneling by a symmetric LHL trilayer thin-film stack embedded in a high-index prism. Considerable simplification arises when the refractive index of the high-index center layer H matches the refractive index of the prism and its thickness is quarter-wave. This leads to a cube design in which zero reflection for the p polarization is achieved at a 45° angle of incidence independent of the thicknesses of the identical symmetric low-index tunnel layers L and L. Arbitrarily high reflectance for the s polarization is obtained at subwavelength thicknesses of the tunnel layers. This is illustrated by an IR Si-cube PBS that uses an embedded ZnS-Si-ZnS trilayer stack.

  10. Attitude control/momentum management and payload pointing in advanced space vehicles

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Jayasuriya, Suhada

    1990-01-01

    The design and evaluation of an attitude control/momentum management system for highly asymmetric spacecraft configurations are presented. The preliminary development and application of a nonlinear control system design methodology for tracking control of uncertain systems, such as spacecraft payload pointing systems are also presented. Control issues relevant to both linear and nonlinear rigid-body spacecraft dynamics are addressed, whereas any structural flexibilities are not taken into consideration. Results from the first task indicate that certain commonly used simplifications in the equations of motions result in unstable attitude control systems, when used for highly asymmetric spacecraft configurations. An approach is suggested circumventing this problem. Additionally, even though preliminary results from the second task are encouraging, the proposed nonlinear control system design method requires further investigation prior to its application and use as an effective payload pointing system design technique.

  11. A novel representation of groundwater dynamics in large-scale land surface modelling

    NASA Astrophysics Data System (ADS)

    Rahman, Mostaquimur; Rosolem, Rafael; Kollet, Stefan

    2017-04-01

    Land surface processes are connected to groundwater dynamics via shallow soil moisture. For example, groundwater affects evapotranspiration (by influencing the variability of soil moisture) and runoff generation mechanisms. However, contemporary Land Surface Models (LSM) generally consider isolated soil columns and free drainage lower boundary condition for simulating hydrology. This is mainly due to the fact that incorporating detailed groundwater dynamics in LSMs usually requires considerable computing resources, especially for large-scale applications (e.g., continental to global). Yet, these simplifications undermine the potential effect of groundwater dynamics on land surface mass and energy fluxes. In this study, we present a novel approach of representing high-resolution groundwater dynamics in LSMs that is computationally efficient for large-scale applications. This new parameterization is incorporated in the Joint UK Land Environment Simulator (JULES) and tested at the continental-scale.

  12. Partition functions. I. Improved partition functions and thermodynamic quantities for normal, equilibrium, and ortho and para molecular hydrogen

    NASA Astrophysics Data System (ADS)

    Popovas, A.; Jørgensen, U. G.

    2016-11-01

    Context. Hydrogen is the most abundant molecule in the Universe. Its thermodynamic quantities dominate the physical conditions in molecular clouds, protoplanetary disks, etc. It is also of high interest in plasma physics. Therefore thermodynamic data for molecular hydrogen have to be as accurate as possible in a wide temperature range. Aims: We here rigorously show the shortcomings of various simplifications that are used to calculate the total internal partition function. These shortcomings can lead to errors of up to 40 percent or more in the estimated partition function. These errors carry on to calculations of thermodynamic quantities. Therefore a more complicated approach has to be taken. Methods: Seven possible simplifications of various complexity are described, together with advantages and disadvantages of direct summation of experimental values. These were compared to what we consider the most accurate and most complete treatment (case 8). Dunham coefficients were determined from experimental and theoretical energy levels of a number of electronically excited states of H2. Both equilibrium and normal hydrogen was taken into consideration. Results: Various shortcomings in existing calculations are demonstrated, and the reasons for them are explained. New partition functions for equilibrium, normal, and ortho and para hydrogen are calculated and thermodynamic quantities are reported for the temperature range 1-20 000 K. Our results are compared to previous estimates in the literature. The calculations are not limited to the ground electronic state, but include all bound and quasi-bound levels of excited electronic states. Dunham coefficients of these states of H2 are also reported. Conclusions: For most of the relevant astrophysical cases it is strongly advised to avoid using simplifications, such as a harmonic oscillator and rigid rotor or ad hoc summation limits of the eigenstates to estimate accurate partition functions and to be particularly careful when using polynomial fits to the computed values. Reported internal partition functions and thermodynamic quantities in the present work are shown to be more accurate than previously available data. The full datasets in 1 K temperature steps are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/595/A130

  13. Ecosystem-scale trade-offs between impacts of ozone and reactive nitrogen

    NASA Astrophysics Data System (ADS)

    Rowe, Ed; Hayes, Felicity; Sawicka, Kasia; Mills, Gina; Jones, Laurence; Moldan, Filip; Sereina, Bassin; van Dijk, Netty; Evans, Chris

    2015-04-01

    Nitrogen (N) deposition stimulates plant productivity in many terrestrial ecosystems. This is clearly beneficial for production agriculture and forestry, but increased litterfall and decreased ground-level light availability reduce the suitability of habitats for many biota (Jones et al., 2014). This mechanism (Hautier et al., 2009), together with the acidifying effects of N (Stevens et al., 2010), has caused considerable biodiversity loss at global scale. Ozone, by contrast, has the effect of reducing plant production, and a simple assessment would suggest that this might mitigate the effects of N pollution. We explored the interactions between ozone and nitrogen at mechanistic level using a version of the MADOC model (Rowe et al., 2014) modified to include effects of ozone. The model was tested against data from long-term monitoring and experimental sites with a focus on nitrogen and/or ozone effects. Effects on biodiversity were assessed by coupling the MADOC model to the MultiMOVE plant species model. We used this model-chain to explore trade-offs and synergies between the impacts of nitrogen and ozone on biodiversity and ecosystem biogeochemistry. In a review of the effects of ozone on ecosystem processes, two consistent effects were found: decreased net primary production due to damage to photosynthetic mechanisms; and an increase in litter nitrogen apparently caused by interference of ozone with the retranslocation process (Mills, in prep.). Insufficient evidence was found to justify inclusion of posited interactive mechanisms such as increased ozone susceptibility with greater nitrogen supply. However, the MADOC model illustrated emergent ozone-nitrogen interactions at ecosystem scale, for example an increase in N leaching due to decreased plant demand and greater litter N content. Empirical evidence for interactive effects of nitrogen and ozone at ecosystem scale is severely lacking, but simulated results were consistent with soil and soil solution observations from long-term experiments with N addition (bog at Whim Moss and coniferous forest at Gårdsjön) and ozone treatments (alpine grassland at Alp Flix). Effects of N pollution on biodiversity were well illustrated by the model chain. Acidification and eutrophication both tended to have negative effects on "positive indicator" species i.e. those that are distinctive for particular habitats, and neutral or positive effects on more ubiquitous species. Simulations suggested that ozone is likely to have beneficial effects on these distinctive species, principally because of decreased productivity. However, this may not occur in reality since responses of individual species to ozone vary considerably, and are not currently included in the model chain. We identify knowledge gaps which would be a useful focus for future experimental studies and surveys. Using relatively simple models of ecosystem biogeochemistry and species responses, together with an awareness of where simplifications might lead to unreliable conclusions, can help clarify research questions to be addressed in experimental studies. Hautier, Y. et al. 2009. Science 324, 636-638. Jones, L. et al. 2014. Ecosystem Services 7, 76-88. Mills, G. et al. in prep. Environmental Pollution. Rowe, E.C. et al. 2014. Environmental Pollution 184, 271-282. Stevens, C.J. et al. 2010. Functional Ecology 24, 478-484.

  14. High-reliability gas-turbine combined-cycle development program: Phase II, Volume 3. Final report

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

    Hecht, K.G.; Sanderson, R.A.; Smith, M.J.

    This three-volume report presents the results of Phase II of the multiphase EPRI-sponsored High-Reliability Gas Turbine Combined-Cycle Development Program whose goal is to achieve a highly reliable gas turbine combined-cycle power plant, available by the mid-1980s, which would be an economically attractive baseload generation alternative for the electric utility industry. The Phase II program objective was to prepare the preliminary design of this power plant. The power plant was addressed in three areas: (1) the gas turbine, (2) the gas turbine ancillaries, and (3) the balance of plant including the steam turbine generator. To achieve the program goals, a gasmore » turbine was incorporated which combined proven reliability characteristics with improved performance features. This gas turbine, designated the V84.3, is the result of a cooperative effort between Kraftwerk Union AG and United Technologies Corporation. Gas turbines of similar design operating in Europe under baseload conditions have demonstrated mean time between failures in excess of 40,000. The reliability characteristics of the gas turbine ancillaries and balance-of-plant equipment were improved through system simplification and component redundancy and by selection of component with inherent high reliability. A digital control system was included with logic, communications, sensor redundancy, and manual backup. An independent condition monitoring and diagnostic system was also included. Program results provide the preliminary design of a gas turbine combined-cycle baseload power plant. This power plant has a predicted mean time between failure of nearly twice the 3000-h EPRI goal. The cost of added reliability features is offset by improved performance, which results in a comparable specific cost and an 8% lower cost of electricty compared to present market offerings.« less

  15. High-reliability gas-turbine combined-cycle development program: Phase II. Final report

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

    Hecht, K.G.; Sanderson, R.A.; Smith, M.J.

    This three-volume report presents the results of Phase II of the multiphase EPRI-sponsored High-Reliability Gas Turbine Combined-Cycle Development Program whose goal is to achieve a highly reliable gas turbine combined-cycle power plant, available by the mid-1980s, which would be an economically attractive baseload generation alternative for the electric utility industry. The Phase II program objective was to prepare the preliminary design of this power plant. This volume presents information of the reliability, availability, and maintainability (RAM) analysis of a representative plant and the preliminary design of the gas turbine, the gas turbine ancillaries, and the balance of plant including themore » steam turbine generator. To achieve the program goals, a gas turbine was incorporated which combined proven reliability characteristics with improved performance features. This gas turbine, designated the V84.3, is the result of a cooperative effort between Kraftwerk Union AG and United Technologies Corporation. Gas turbines of similar design operating in Europe under baseload conditions have demonstrated mean time between failures in excess of 40,000 hours. The reliability characteristics of the gas turbine ancillaries and balance-of-plant equipment were improved through system simplification and component redundancy and by selection of component with inherent high reliability. A digital control system was included with logic, communications, sensor redundancy, and mandual backup. An independent condition monitoring and diagnostic system was also included. Program results provide the preliminary design of a gas turbine combined-cycle baseload power plant. This power plant has a predicted mean time between failure of nearly twice the 3000-hour EPRI goal. The cost of added reliability features is offset by improved performance, which results in a comparable specific cost and an 8% lower cost of electricity compared to present market offerings.« less

  16. Three-dimensional time-dependent STAR reactor kinetics analyses coupled with RETRAN and MCPWR system response

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

    Feltus, M.A.

    1989-11-01

    The operation of a nuclear power plant must be regularly supported by various reactor dynamics and thermal-hydraulic analyses, which may include final safety analysis report (FSAR) design-basis calculations, and conservative and best-estimate analyses. The development and improvement of computer codes and analysis methodologies provide many advantages, including the ability to evaluate the effect of modeling simplifications and assumptions made in previous reactor kinetics and thermal-hydraulic calculations. This paper describes the results of using the RETRAN, MCPWR, and STAR codes in a tandem, predictive-corrective manner for three pressurized water reactor (PWR) transients: (a) loss of feedwater (LOF) anticipated transient without scrammore » (ATWS), (b) station blackout ATWS, and (c) loss of total reactor coolant system (RCS) flow with a scram.« less

  17. Long lifetime fast spectrum reactor for lunar surface power system

    NASA Astrophysics Data System (ADS)

    Kambe, Mitsuru

    1993-01-01

    In the framework of innovative reactor research activities, a conceptual design study of fast spectrum reactor and primary system for 800 kWe lunar surface power system to be combined with potassium Rankine cycle power conversion has been conducted to meet the power requirements of the lunar base activities in the next century. The reactor subsystem is characterized by RAPID (Refueling by All Pins Integrated Design) concept to enhance inherent safety and to enable quick and simplifed refueling in every 10 years. RAPID concept affords power plant design lifetime of up to 30 years. Integrity of the reactor structure and replacement of failed primary circuits are also discussed. Substantial reduction in per-kWh cost on considering launch, emplacement, and final disposition can be expected by a long system lifetime.

  18. Simplification of the helical TEN2 laser

    NASA Astrophysics Data System (ADS)

    Krahn, K.-H.

    1980-04-01

    The observation that the helical TEN2 laser can effectively be simplified by giving up the use of decoupling elements as well as by abolishing the segmentation of the electrode structure is examined. Although, as a consequence of this simplification, the operating pressure range was slightly decreased, the output power could be improved by roughly 30%, a result which is attributed to the new electrode geometry exhibiting lower inductance and lower damping losses.

  19. Rightsizing LISA

    NASA Technical Reports Server (NTRS)

    Stebbins, Robin T.

    2009-01-01

    The LISA science requirements and conceptual design have been fairly stable for over a decade. In the interest of reducing costs, the LISA Project at NASA has looked for simplifications of the architecture, at downsizing of subsystems, and at descopes of the entire mission. This is a natural activity of the formulation phase, and one that is particularly timely in the current NASA budgetary context. There is, and will continue to be, enormous pressure for cost reduction from both ESA and NASA, reviewers and the broader research community. Here, the rationale for the baseline architecture is reviewed, and recent efforts to find simplifications and other reductions that might lead to savings are reported. A few possible simplifications have been found in the LISA baseline architecture. In the interest of exploring cost sensitivity, one moderate and one aggressive descope have been evaluated; the cost savings are modest and the loss of science is not.

  20. Electric Power Distribution System Model Simplification Using Segment Substitution

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

    Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat

    Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers modelmore » bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). In contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.« less

  1. An alternative Biot's displacement formulation for porous materials.

    PubMed

    Dazel, Olivier; Brouard, Bruno; Depollier, Claude; Griffiths, Stéphane

    2007-06-01

    This paper proposes an alternative displacement formulation of Biot's linear model for poroelastic materials. Its advantage is a simplification of the formalism without making any additional assumptions. The main difference between the method proposed in this paper and the original one is the choice of the generalized coordinates. In the present approach, the generalized coordinates are chosen in order to simplify the expression of the strain energy, which is expressed as the sum of two decoupled terms. Hence, new equations of motion are obtained whose elastic forces are decoupled. The simplification of the formalism is extended to Biot and Willis thought experiments, and simpler expressions of the parameters of the three Biot waves are also provided. A rigorous derivation of equivalent and limp models is then proposed. It is finally shown that, for the particular case of sound-absorbing materials, additional simplifications of the formalism can be obtained.

  2. The power of simplification: Operator interface with the AP1000{sup R} during design-basis and beyond design-basis events

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

    Williams, M. G.; Mouser, M. R.; Simon, J. B.

    2012-07-01

    The AP1000{sup R} plant is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance, safety and cost. The passive safety features are designed to function without safety-grade support systems such as component cooling water, service water, compressed air or HVAC. The AP1000 passive safety features achieve and maintain safe shutdown in case of a design-basis accident for 72 hours without need for operator action, meeting the expectations provided in the European Utility Requirements and the Utility Requirement Document for passive plants. Limited operator actions may be required to maintain safe conditionsmore » in the spent fuel pool (SFP) via passive means. This safety approach therefore minimizes the reliance on operator action for accident mitigation, and this paper examines the operator interaction with the Human-System Interface (HSI) as the severity of an accident increases from an anticipated transient to a design basis accident and finally, to a beyond-design-basis event. The AP1000 Control Room design provides an extremely effective environment for addressing the first 72 hours of design-basis events and transients, providing ease of information dissemination and minimal reliance upon operator actions. Symptom-based procedures including Emergency Operating Procedures (EOPs), Abnormal Operating Procedures (AOPs) and Alarm Response Procedures (ARPs) are used to mitigate design basis transients and accidents. Use of the Computerized Procedure System (CPS) aids the operators during mitigation of the event. The CPS provides cues and direction to the operators as the event progresses. If the event becomes progressively worse or lasts longer than 72 hours, and depending upon the nature of failures that may have occurred, minimal operator actions may be required outside of the control room in areas that have been designed to be accessible using components that have been designed to be reliable in these conditions. The primary goal of any such actions is to maintain or refill the passive inventory available to cool the core, containment and spent fuel pool in the safety-related and seismically qualified Passive Containment Cooling Water Storage Tank (PCCWST). The seismically-qualified, ground-mounted Passive Containment Cooling Ancillary Water Storage Tank (PCCAWST) is also available for this function as appropriate. The primary effect of these actions would be to increase the coping time for the AP1000 during design basis events, as well as events such as those described above, from 72 hours without operator intervention to 7 days with minimal operator actions. These Operator actions necessary to protect the health and safety of the public are addressed in the Post-72 Hour procedures, as well as some EOPs, AOPs, ARPs and the Severe Accident Management Guidelines (SAMGs). Should the event continue to become more severe and plant conditions degrade further with indications of inadequate core cooling, the SAMGs provide guidance for strategies to address these hypothetical severe accident conditions. The AP1000 SAMG diagnoses and actions are prioritized to first utilize the AP1000 features that are expected to retain a damaged core inside the reactor vessel. Only one strategy is undertaken at any time. This strategy will be followed and its effectiveness evaluated before other strategies are undertaken. This is a key feature of both the symptom-oriented AP1000 EOPs and the AP1000 SAMGs which maximizes the probability of retaining a damaged core inside the reactor vessel and containment while minimizing the chances for confusion and human errors during implementation. The AP1000 SAMGs are simple and straight-forward and have been developed with considerable input from human factors and plant operations experts. Most importantly, and different from severe accident management strategies for other plants, the AP1000 SAMGs do not require diagnosis of the location of the core (i.e., whether reactor vessel failure has occurred). This is a fundamental consequence of the AP1000 In-Vessel Retention approach, which allows severe accident management to be based on fundamental principles (e.g. provide coolant as close as possible to the core) that do not change during a specific event. This eliminates the need for one of the more difficult diagnostic requirements, since reactor vessel failure does not directly relate to any measurable plant parameter, and differs from other designs in that an engineered failure of the pressure vessel' (e.g. core catcher) is never required. (authors)« less

  3. Advanced development of Pb-salt semiconductor lasers for the 8.0 to 15.0 micrometer spectral region

    NASA Technical Reports Server (NTRS)

    Linden, K. J.; Butler, J. F.; Nill, K. W.

    1977-01-01

    The technology was studied for producing Pb-salt diode lasers for the 8-51 micron spectral region suitable for use as local oscillators in a passive Laser Heterodyne Spectrometer (LHS). Consideration was given to long range NASA plans for the utilization of the passive LHS in a space shuttle environment. The general approach was to further develop the method of compositional interdiffusion (CID) recently reported, and used successfully at shorter wavelength. This technology was shown to provide an effective and reproducible method of producing a single-heterostructure (SH) diode of either the heterojunction or single-sided configuration. Performance specifications were exceeded in several devices, with single-ended CW power outputs as high as 0.88 milliwatts in a mode being achieved. The majority of the CID lasers fabricated had CW operating temperatures of over 60K; 30% of them operated CW above the boiling temperature of liquid nitrogen. CW operation above liquid nitrogen temperature was possible for wavelengths as long as 10.3 microns. Operation at 77K is significant with respect to space shuttle operations since its allows considerable simplification of cooling method.

  4. Siting Issues for Solar Thermal Power Plants with Small Community Applications

    NASA Technical Reports Server (NTRS)

    Holbeck, J. J.; Ireland, S. J.

    1978-01-01

    Technologies for solar thermal plants are being developed to provide energy alternatives for the future. Implementation of these plants requires consideration of siting issues as well as power system technology. While many conventional siting considerations are applicable, there is also a set of unique siting issues for solar thermal plants. Early experimental plants will have special siting considerations. The siting issues associated with small, dispersed solar thermal power plants in the 1 to 10 MWe power range for utility/small community applications are considered. Some specific requirements refer to the first 1 MWe engineering experiment for the Small Power Systems Applications (SPSA) Project. The siting issues themselves are discussed in three categories: (1) system resource requirements, (2) environmental effects on the system, and (3) potential impact of the plant on the environment. Within these categories, specific issues are discussed in a qualitative manner. Examples of limiting factors for some issues are taken from studies of other solar systems.

  5. A Landscape View of Agricultural Insecticide Use across the Conterminous US from 1997 through 2012

    DOE PAGES

    Meehan, Timothy D.; Gratton, Claudio; Zhang, Youjun

    2016-11-30

    Simplification of agricultural landscapes is expected to have positive effects on many crop pests and negative effects on their natural enemies, potentially leading to increased pest pressure, decreased crop yield, and increased insecticide use. While many intermediate links in this causal chain have empirical support, there is mixed evidence for ultimate relationships between landscape simplification, crop yield, and insecticide use, especially at large spatial and temporal scales. We explored relationships between landscape simplification (proportion of a county in harvested cropland) and insecticide use (proportion of harvested cropland treated with insecticides), using county-level data from the US Census of Agriculture andmore » a variety of standard and spatiotemporal regression techniques. The best model indicated that insecticide use across the US has increased between 1997 and 2012, was strongly dependent on the crops grown in a county, increased with average farm income and size, and increased with annual growing degree days. After accounting for those variables, and other unidentified spatial and temporal structure in the data, there remained a statistically significant, moderate, positive relationship between insecticide use and landscape simplification. Finally, these results lend general support to the causal chain outlined above, and to the notion that a landscape perspective is useful for managing ecosystem services that are provided by mobile organisms and valuable to agriculture.« less

  6. A Landscape View of Agricultural Insecticide Use across the Conterminous US from 1997 through 2012

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

    Meehan, Timothy D.; Gratton, Claudio; Zhang, Youjun

    Simplification of agricultural landscapes is expected to have positive effects on many crop pests and negative effects on their natural enemies, potentially leading to increased pest pressure, decreased crop yield, and increased insecticide use. While many intermediate links in this causal chain have empirical support, there is mixed evidence for ultimate relationships between landscape simplification, crop yield, and insecticide use, especially at large spatial and temporal scales. We explored relationships between landscape simplification (proportion of a county in harvested cropland) and insecticide use (proportion of harvested cropland treated with insecticides), using county-level data from the US Census of Agriculture andmore » a variety of standard and spatiotemporal regression techniques. The best model indicated that insecticide use across the US has increased between 1997 and 2012, was strongly dependent on the crops grown in a county, increased with average farm income and size, and increased with annual growing degree days. After accounting for those variables, and other unidentified spatial and temporal structure in the data, there remained a statistically significant, moderate, positive relationship between insecticide use and landscape simplification. Finally, these results lend general support to the causal chain outlined above, and to the notion that a landscape perspective is useful for managing ecosystem services that are provided by mobile organisms and valuable to agriculture.« less

  7. Grassland-Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality

    NASA Astrophysics Data System (ADS)

    Lemaire, Gilles; Gastal, François; Franzluebbers, Alan; Chabbi, Abad

    2015-11-01

    A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-soil-plant interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.

  8. Grassland-Cropping Rotations: An Avenue for Agricultural Diversification to Reconcile High Production with Environmental Quality.

    PubMed

    Lemaire, Gilles; Gastal, François; Franzluebbers, Alan; Chabbi, Abad

    2015-11-01

    A need to increase agricultural production across the world to ensure continued food security appears to be at odds with the urgency to reduce the negative environmental impacts of intensive agriculture. Around the world, intensification has been associated with massive simplification and uniformity at all levels of organization, i.e., field, farm, landscape, and region. Therefore, we postulate that negative environmental impacts of modern agriculture are due more to production simplification than to inherent characteristics of agricultural productivity. Thus by enhancing diversity within agricultural systems, it should be possible to reconcile high quantity and quality of food production with environmental quality. Intensification of livestock and cropping systems separately within different specialized regions inevitably leads to unacceptable environmental impacts because of the overly uniform land use system in intensive cereal areas and excessive N-P loads in intensive animal areas. The capacity of grassland ecosystems to couple C and N cycles through microbial-soil-plant interactions as a way for mitigating the environmental impacts of intensive arable cropping system was analyzed in different management options: grazing, cutting, and ley duration, in order to minimize trade-offs between production and the environment. We suggest that integrated crop-livestock systems are an appropriate strategy to enhance diversity. Sod-based rotations can temporally and spatially capture the benefits of leys for minimizing environmental impacts, while still maintaining periods and areas of intensive cropping. Long-term experimental results illustrate the potential of such systems to sequester C in soil and to reduce and control N emissions to the atmosphere and hydrosphere.

  9. Simplification of a scoring system maintained overall accuracy but decreased the proportion classified as low risk.

    PubMed

    Sanders, Sharon; Flaws, Dylan; Than, Martin; Pickering, John W; Doust, Jenny; Glasziou, Paul

    2016-01-01

    Scoring systems are developed to assist clinicians in making a diagnosis. However, their uptake is often limited because they are cumbersome to use, requiring information on many predictors, or complicated calculations. We examined whether, and how, simplifications affected the performance of a validated score for identifying adults with chest pain in an emergency department who have low risk of major adverse cardiac events. We simplified the Emergency Department Assessment of Chest pain Score (EDACS) by three methods: (1) giving equal weight to each predictor included in the score, (2) reducing the number of predictors, and (3) using both methods--giving equal weight to a reduced number of predictors. The diagnostic accuracy of the simplified scores was compared with the original score in the derivation (n = 1,974) and validation (n = 909) data sets. There was no difference in the overall accuracy of the simplified versions of the score compared with the original EDACS as measured by the area under the receiver operating characteristic curve (0.74 to 0.75 for simplified versions vs. 0.75 for the original score in the validation cohort). With score cut-offs set to maintain the sensitivity of the combination of score and tests (electrocardiogram and cardiac troponin) at a level acceptable to clinicians (99%), simplification reduced the proportion of patients classified as low risk from 50% with the original score to between 22% and 42%. Simplification of a clinical score resulted in similar overall accuracy but reduced the proportion classified as low risk and therefore eligible for early discharge compared with the original score. Whether the trade-off is acceptable, will depend on the context in which the score is to be used. Developers of clinical scores should consider simplification as a method to increase uptake, but further studies are needed to determine the best methods of deriving and evaluating simplified scores. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Simplification and its consequences in biological modelling: conclusions from a study of calcium oscillations in hepatocytes.

    PubMed

    Hetherington, James P J; Warner, Anne; Seymour, Robert M

    2006-04-22

    Systems Biology requires that biological modelling is scaled up from small components to system level. This can produce exceedingly complex models, which obscure understanding rather than facilitate it. The successful use of highly simplified models would resolve many of the current problems faced in Systems Biology. This paper questions whether the conclusions of simple mathematical models of biological systems are trustworthy. The simplification of a specific model of calcium oscillations in hepatocytes is examined in detail, and the conclusions drawn from this scrutiny generalized. We formalize our choice of simplification approach through the use of functional 'building blocks'. A collection of models is constructed, each a progressively more simplified version of a well-understood model. The limiting model is a piecewise linear model that can be solved analytically. We find that, as expected, in many cases the simpler models produce incorrect results. However, when we make a sensitivity analysis, examining which aspects of the behaviour of the system are controlled by which parameters, the conclusions of the simple model often agree with those of the richer model. The hypothesis that the simplified model retains no information about the real sensitivities of the unsimplified model can be very strongly ruled out by treating the simplification process as a pseudo-random perturbation on the true sensitivity data. We conclude that sensitivity analysis is, therefore, of great importance to the analysis of simple mathematical models in biology. Our comparisons reveal which results of the sensitivity analysis regarding calcium oscillations in hepatocytes are robust to the simplifications necessarily involved in mathematical modelling. For example, we find that if a treatment is observed to strongly decrease the period of the oscillations while increasing the proportion of the cycle during which cellular calcium concentrations are rising, without affecting the inter-spike or maximum calcium concentrations, then it is likely that the treatment is acting on the plasma membrane calcium pump.

  11. Novel limiter pump topologies

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

    Schultz, J.H.

    1981-01-01

    The use of limiter pumps as the principle plasma exhaust system of a magnetic confinement fusion device promises significant simplification, when compared to previously investigating divertor based systems. Further simplifications, such as the integration of the exhaust system with a radio frequency heating system and with the main reactor shield and structure are investigated below. The integrity of limiters in a reactor environment is threatened by many mechanisms, the most severe of which may be erosion by sputtering. Two novel topolgies are suggested which allow high erosion without limiter failure.

  12. An Agent Based Collaborative Simplification of 3D Mesh Model

    NASA Astrophysics Data System (ADS)

    Wang, Li-Rong; Yu, Bo; Hagiwara, Ichiro

    Large-volume mesh model faces the challenge in fast rendering and transmission by Internet. The current mesh models obtained by using three-dimensional (3D) scanning technology are usually very large in data volume. This paper develops a mobile agent based collaborative environment on the development platform of mobile-C. Communication among distributed agents includes grasping image of visualized mesh model, annotation to grasped image and instant message. Remote and collaborative simplification can be efficiently conducted by Internet.

  13. The representation of manipulable solid objects in a relational database

    NASA Technical Reports Server (NTRS)

    Bahler, D.

    1984-01-01

    This project is concerned with the interface between database management and solid geometric modeling. The desirability of integrating computer-aided design, manufacture, testing, and management into a coherent system is by now well recognized. One proposed configuration for such a system uses a relational database management system as the central focus; the various other functions are linked through their use of a common data repesentation in the data manager, rather than communicating pairwise to integrate a geometric modeling capability with a generic relational data managemet system in such a way that well-formed questions can be posed and answered about the performance of the system as a whole. One necessary feature of any such system is simplification for purposes of anaysis; this and system performance considerations meant that a paramount goal therefore was that of unity and simplicity of the data structures used.

  14. Variation of the shower lateral spread with air temperature at the ground

    NASA Astrophysics Data System (ADS)

    Wilczyńska, B.; Engel, R.; Homola, P.; Keilhauer, B.; Klages, H.; Pękala, J.; Wilczyński, H.

    The vertical profile of air density at a given site varies considerably with time. Well understood seasonal differences are present, but sizeable effects on shorter time scales, like day to night or day to day variations, are also observed. In consequence, the Moliere radius changes, influencing the lateral distribution of particles in the air showers and therefore may influence the shower detection in surface detector arrays. In air shower reconstruction, usually seasonal average profiles of the atmosphere are used, because local daily measurements of the profile are rarely available. Therefore, the daily fluctuations of the atmosphere are not accounted for. This simplification increases the inaccuracies of shower reconstruction. We show that a universal correlation exists between the ground temperature and the shape of the atmospheric profile, up to altitudes of several kilometers, hence providing a method to reduce inaccuracies in shower reconstruction due to weather variation.

  15. HealthMarts, HIPCs (health insurance purchasing cooperatives), MEWAs (multiple employee welfare arrangements), and AHPs (association health plans): a guide for the perplexed.

    PubMed

    Hall, M A; Wicks, E K; Lawlor, J S

    2001-01-01

    This paper considers how pending proposals to authorize new forms of group purchasing arrangements for health insurance would fit and function within the existing, highly complex market and regulatory landscape and whether these proposals are likely to meet their stated objectives and avoid unintended consequences. Cost savings are more likely to result from increased risk segmentation than through true market efficiencies. Thus, these proposals could erode previous market reforms whose goal is increased risk pooling. On the other hand, these proposals contain important enhancements, clarifications, and simplification of state and federal regulatory oversight of group purchasing vehicles. Also, they address some of the problems that have hampered the performance of purchasing cooperatives. On balance, although these proposals should receive cautious and careful consideration, they are not likely to produce a significant overall reduction in premiums or increase in coverage.

  16. Oscillator strengths, first-order properties, and nuclear gradients for local ADC(2).

    PubMed

    Schütz, Martin

    2015-06-07

    We describe theory and implementation of oscillator strengths, orbital-relaxed first-order properties, and nuclear gradients for the local algebraic diagrammatic construction scheme through second order. The formalism is derived via time-dependent linear response theory based on a second-order unitary coupled cluster model. The implementation presented here is a modification of our previously developed algorithms for Laplace transform based local time-dependent coupled cluster linear response (CC2LR); the local approximations thus are state specific and adaptive. The symmetry of the Jacobian leads to considerable simplifications relative to the local CC2LR method; as a result, a gradient evaluation is about four times less expensive. Test calculations show that in geometry optimizations, usually very similar geometries are obtained as with the local CC2LR method (provided that a second-order method is applicable). As an exemplary application, we performed geometry optimizations on the low-lying singlet states of chlorophyllide a.

  17. A modal separation measurement technique for broadband noise propagating inside circular ducts

    NASA Technical Reports Server (NTRS)

    Kerschen, E. J.; Johnston, J. P.

    1981-01-01

    A measurement technique which separates broadband noise propagating inside circular ducts into the acoustic duct modes is developed. The technique is also applicable to discrete frequency noise. The acoustic modes are produced by weighted combinations of the instantaneous outputs of microphones spaced around the duct circumference. The technique is compared with the cross spectral density approach presently available and found to have certain advantages, and disadvantages. Considerable simplification of both the new technique and the cross spectral density approach occurs when no correlation exists between different circumferential mode orders. The properties leading to uncorrelated modes and experimental tests which verify this condition are discussed. The modal measurement technique is applied to the case of broadband noise generated by flow through a coaxial obstruction (nozzle or orifice) in a pipe. Different circumferential mode orders are shown to be uncorrelated for this type of noise source.

  18. Immobilised lipases in the cosmetics industry.

    PubMed

    Ansorge-Schumacher, Marion B; Thum, Oliver

    2013-08-07

    Commercial products for personal care, generally perceived as cosmetics, have an important impact on everyday life worldwide. Accordingly, the market for both consumer products and specialty chemicals comprising their ingredients is considerable. Lipases have started to play a minor role as active ingredients in so-called 'functional cosmetics' as well as a major role as catalysts for the industrial production of various specialty esters, aroma compounds and active agents. Interestingly, both applications almost always require preparation by appropriate immobilisation techniques. In addition, for catalytic use special reactor concepts often have to be employed due to the mostly limited stability of these preparations. Nevertheless, these processes show distinct advantages based on process simplification, product quality and environmental footprint and are therefore apt to more and more replace traditional chemical processes. Here, for the first time a review on the various aspects of using immobilised lipases in the cosmetics industry is given.

  19. Etiology, pathogenesis, and therapy according to Pierre Janet concerning conversion disorders and dissociative disorders.

    PubMed

    Bühler, Karl-Ernst; Heim, Gerhard

    2011-01-01

    Pierre Janet's works on conversion disorders or dissociative disorders has mainly fallen to the wayside in favour of Freud's works. In the first part of this paper, Janet's conception of hysteria is discussed and his place in French psychiatry described. Different aspects of Janet's diathesis-stress approach are presented (particularly the pathogenic concept of fixed ideas), which refer not only to a conception of hysteria but also to traumatic (stress) disorders and other psychological disturbances. The second part of the paper details the varieties of Janetian therapeutic treatments of these disorders: the "liquidation" of fixed ideas by hypnosis and suggestion, confrontation techniques, which resemble contemporary cognitive behavioural approaches, and special cognitive ("logagogic") interventions. Finally, we discuss the various treatment strategies based on psychoeconomic considerations such as physical or psycho-phyical therapies, psychoeducation, treatment through rest, and simplification of life for dealing with basic disturbances of psychic disorders.

  20. Sensitivity and Switching Delay in Trigger Circuits; SENSIBILITA E RITARDO ENI CIRCUITI A SCATTO

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

    De Lotto, I.; Stanchi, L.

    The problem of regeneration in trigger circuits is studied, particularly in relation to switching delay and switching time. The factors that affect the speed, such as the threshold as a function of the input signal duration, are examined. The sensitivity of the circuit is also discussed. The characteristics of the dipole equivalent to a trigger circuit are determined, and the switching delay and switching rise time are examined using considerable simplifications (circuits with constant parameters) and graphical methods. For the particular case of a transistor circuit, the equation of the equivalent circuit is derived taking into account the nonlinearity ofmore » the parameters. This equation is processed by means of an analog computer. Using experimental data, the circuits are classified according to their sensitivity and the switching delay. A merit figure is obtained for synthetically evaluating different circuits and optimizing circuit sensitivity and speed. (auth)« less

  1. Panic disorder: a review of DSM-IV panic disorder and proposals for DSM-V.

    PubMed

    Craske, Michelle G; Kircanski, Katharina; Epstein, Alyssa; Wittchen, Hans-Ulrich; Pine, Danny S; Lewis-Fernández, Roberto; Hinton, Devon

    2010-02-01

    This review covers the literature since the publication of DSM-IV on the diagnostic criteria for panic attacks (PAs) and panic disorder (PD). Specific recommendations are made based on the evidence available. In particular, slight changes are proposed for the wording of the diagnostic criteria for PAs to ease the differentiation between panic and surrounding anxiety; simplification and clarification of the operationalization of types of PAs (expected vs. unexpected) is proposed; and consideration is given to the value of PAs as a specifier for all DSM diagnoses and to the cultural validity of certain symptom profiles. In addition, slight changes are proposed for the wording of the diagnostic criteria to increase clarity and parsimony of the criteria. Finally, based on the available evidence, no changes are proposed with regard to the developmental expression of PAs or PD. This review presents a number of options and preliminary recommendations to be considered for DSM-V.

  2. Taming the nonlinearity of the Einstein equation.

    PubMed

    Harte, Abraham I

    2014-12-31

    Many of the technical complications associated with the general theory of relativity ultimately stem from the nonlinearity of Einstein's equation. It is shown here that an appropriate choice of dynamical variables may be used to eliminate all such nonlinearities beyond a particular order: Both Landau-Lifshitz and tetrad formulations of Einstein's equation are obtained that involve only finite products of the unknowns and their derivatives. Considerable additional simplifications arise in physically interesting cases where metrics become approximately Kerr or, e.g., plane waves, suggesting that the variables described here can be used to efficiently reformulate perturbation theory in a variety of contexts. In all cases, these variables are shown to have simple geometrical interpretations that directly relate the local causal structure associated with the metric of interest to the causal structure associated with a prescribed background. A new method to search for exact solutions is outlined as well.

  3. Lunar base agriculture: Soils for plant growth

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W. (Editor); Henninger, Donald L. (Editor)

    1989-01-01

    This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.

  4. Flexural analysis of palm fiber reinforced hybrid polymer matrix composite

    NASA Astrophysics Data System (ADS)

    Venkatachalam, G.; Gautham Shankar, A.; Raghav, Dasarath; Santhosh Kiran, R.; Mahesh, Bhargav; Kumar, Krishna

    2015-07-01

    Uncertainty in availability of fossil fuels in the future and global warming increased the need for more environment friendly materials. In this work, an attempt is made to fabricate a hybrid polymer matrix composite. The blend is a mixture of General Purpose Resin and Cashew Nut Shell Liquid, a natural resin extracted from cashew plant. Palm fiber, which has high strength, is used as reinforcement material. The fiber is treated with alkali (NaOH) solution to increase its strength and adhesiveness. Parametric study of flexure strength is carried out by varying alkali concentration, duration of alkali treatment and fiber volume. Taguchi L9 Orthogonal array is followed in the design of experiments procedure for simplification. With the help of ANOVA technique, regression equations are obtained which gives the level of influence of each parameter on the flexure strength of the composite.

  5. Electric Power Distribution System Model Simplification Using Segment Substitution

    DOE PAGES

    Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat; ...

    2017-09-20

    Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers modelmore » bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). Finally, in contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.« less

  6. Landscape simplification filters species traits and drives biotic homogenization

    PubMed Central

    Gámez-Virués, Sagrario; Perović, David J.; Gossner, Martin M.; Börschig, Carmen; Blüthgen, Nico; de Jong, Heike; Simons, Nadja K.; Klein, Alexandra-Maria; Krauss, Jochen; Maier, Gwen; Scherber, Christoph; Steckel, Juliane; Rothenwöhrer, Christoph; Steffan-Dewenter, Ingolf; Weiner, Christiane N.; Weisser, Wolfgang; Werner, Michael; Tscharntke, Teja; Westphal, Catrin

    2015-01-01

    Biodiversity loss can affect the viability of ecosystems by decreasing the ability of communities to respond to environmental change and disturbances. Agricultural intensification is a major driver of biodiversity loss and has multiple components operating at different spatial scales: from in-field management intensity to landscape-scale simplification. Here we show that landscape-level effects dominate functional community composition and can even buffer the effects of in-field management intensification on functional homogenization, and that animal communities in real-world managed landscapes show a unified response (across orders and guilds) to both landscape-scale simplification and in-field intensification. Adults and larvae with specialized feeding habits, species with shorter activity periods and relatively small body sizes are selected against in simplified landscapes with intense in-field management. Our results demonstrate that the diversity of land cover types at the landscape scale is critical for maintaining communities, which are functionally diverse, even in landscapes where in-field management intensity is high. PMID:26485325

  7. Simplification of the DPPH assay for estimating the antioxidant activity of wine and wine by-products.

    PubMed

    Carmona-Jiménez, Yolanda; García-Moreno, M Valme; Igartuburu, Jose M; Garcia Barroso, Carmelo

    2014-12-15

    The DPPH assay is one of the most commonly employed methods for measuring antioxidant activity. Even though this method is considered very simple and efficient, it does present various limitations which make it complicated to perform. The range of linearity between the DPPH inhibition percentage and sample concentration has been studied with a view to simplifying the method for characterising samples of wine origin. It has been concluded that all the samples are linear in a range of inhibition below 40%, which allows the analysis to be simplified. A new parameter more appropriate for the simplification, the EC20, has been proposed to express the assay results. Additionally, the reaction time was analysed with the object of avoiding the need for kinetic studies in the method. The simplifications considered offer a more functional method, without significant errors, which could be used for routine analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Simplification of Markov chains with infinite state space and the mathematical theory of random gene expression bursts.

    PubMed

    Jia, Chen

    2017-09-01

    Here we develop an effective approach to simplify two-time-scale Markov chains with infinite state spaces by removal of states with fast leaving rates, which improves the simplification method of finite Markov chains. We introduce the concept of fast transition paths and show that the effective transitions of the reduced chain can be represented as the superposition of the direct transitions and the indirect transitions via all the fast transition paths. Furthermore, we apply our simplification approach to the standard Markov model of single-cell stochastic gene expression and provide a mathematical theory of random gene expression bursts. We give the precise mathematical conditions for the bursting kinetics of both mRNAs and proteins. It turns out that random bursts exactly correspond to the fast transition paths of the Markov model. This helps us gain a better understanding of the physics behind the bursting kinetics as an emergent behavior from the fundamental multiscale biochemical reaction kinetics of stochastic gene expression.

  9. Simplification of Markov chains with infinite state space and the mathematical theory of random gene expression bursts

    NASA Astrophysics Data System (ADS)

    Jia, Chen

    2017-09-01

    Here we develop an effective approach to simplify two-time-scale Markov chains with infinite state spaces by removal of states with fast leaving rates, which improves the simplification method of finite Markov chains. We introduce the concept of fast transition paths and show that the effective transitions of the reduced chain can be represented as the superposition of the direct transitions and the indirect transitions via all the fast transition paths. Furthermore, we apply our simplification approach to the standard Markov model of single-cell stochastic gene expression and provide a mathematical theory of random gene expression bursts. We give the precise mathematical conditions for the bursting kinetics of both mRNAs and proteins. It turns out that random bursts exactly correspond to the fast transition paths of the Markov model. This helps us gain a better understanding of the physics behind the bursting kinetics as an emergent behavior from the fundamental multiscale biochemical reaction kinetics of stochastic gene expression.

  10. Progressive simplification and transmission of building polygons based on triangle meshes

    NASA Astrophysics Data System (ADS)

    Li, Hongsheng; Wang, Yingjie; Guo, Qingsheng; Han, Jiafu

    2010-11-01

    Digital earth is a virtual representation of our planet and a data integration platform which aims at harnessing multisource, multi-resolution, multi-format spatial data. This paper introduces a research framework integrating progressive cartographic generalization and transmission of vector data. The progressive cartographic generalization provides multiple resolution data from coarse to fine as key scales and increments between them which is not available in traditional generalization framework. Based on the progressive simplification algorithm, the building polygons are triangulated into meshes and encoded according to the simplification sequence of two basic operations, edge collapse and vertex split. The map data at key scales and encoded increments between them are stored in a multi-resolution file. As the client submits requests to the server, the coarsest map is transmitted first and then the increments. After data decoding and mesh refinement the building polygons with more details will be visualized. Progressive generalization and transmission of building polygons is demonstrated in the paper.

  11. Electric Power Distribution System Model Simplification Using Segment Substitution

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

    Reiman, Andrew P.; McDermott, Thomas E.; Akcakaya, Murat

    Quasi-static time-series (QSTS) simulation is used to simulate the behavior of distribution systems over long periods of time (typically hours to years). The technique involves repeatedly solving the load-flow problem for a distribution system model and is useful for distributed energy resource (DER) planning. When a QSTS simulation has a small time step and a long duration, the computational burden of the simulation can be a barrier to integration into utility workflows. One way to relieve the computational burden is to simplify the system model. The segment substitution method of simplifying distribution system models introduced in this paper offers modelmore » bus reduction of up to 98% with a simplification error as low as 0.2% (0.002 pu voltage). Finally, in contrast to existing methods of distribution system model simplification, which rely on topological inspection and linearization, the segment substitution method uses black-box segment data and an assumed simplified topology.« less

  12. Three-dimensional modeling of the cochlea by use of an arc fitting approach.

    PubMed

    Schurzig, Daniel; Lexow, G Jakob; Majdani, Omid; Lenarz, Thomas; Rau, Thomas S

    2016-12-01

    A cochlea modeling approach is presented allowing for a user defined degree of geometry simplification which automatically adjusts to the patient specific anatomy. Model generation can be performed in a straightforward manner due to error estimation prior to the actual generation, thus minimizing modeling time. Therefore, the presented technique is well suited for a wide range of applications including finite element analyses where geometrical simplifications are often inevitable. The method is presented for n=5 cochleae which were segmented using a custom software for increased accuracy. The linear basilar membrane cross sections are expanded to areas while the scalae contours are reconstructed by a predefined number of arc segments. Prior to model generation, geometrical errors are evaluated locally for each cross section as well as globally for the resulting models and their basal turn profiles. The final combination of all reconditioned features to a 3D volume is performed in Autodesk Inventor using the loft feature. Due to the volume generation based on cubic splines, low errors could be achieved even for low numbers of arc segments and provided cross sections, both of which correspond to a strong degree of model simplification. Model generation could be performed in a time efficient manner. The proposed simplification method was proven to be well suited for the helical cochlea geometry. The generated output data can be imported into commercial software tools for various analyses representing a time efficient way to create cochlea models optimally suited for the desired task.

  13. Reciprocal interactions between fluvial processes and riparian plants at multiple scales: ecogeomorphic feedbacks drive coevolution of floodplain morphology and vegetation communities

    NASA Astrophysics Data System (ADS)

    Stella, J. C.; Kui, L.; Diehl, R. M.; Bywater-Reyes, S.; Wilcox, A. C.; Shafroth, P. B.; Lightbody, A.

    2017-12-01

    Fluvial forces interact with woody riparian plants in complex ways to influence the coevolution of river morphology and floodplain plant communities. Here, we report on an integrated suite of multi-disciplinary studies that contrast the responses of plants with different morphologies, tamarisk (Tamarix spp.) and cottonwood (Populus fremontii) in terms of (1) differences in vulnerability to scour and burial during floods; (2) interactions and feedbacks between plants and river morphodynamics; and (3) long-term coevolution of river floodplains and riparian communities following flow regulation from dams. The focus of these studies is sand-bed rivers in arid-land regions where invasion by tamarisk has strongly influenced riverine plant communities and geomorphic processes. We complemented a suite of field-scale flume experiments using live seedlings to quantify the initial stages of plant-river interactions with an analysis of long-term vegetation and geomorphic changes along the dammed Bill Williams River (AZ, USA) using time-series air photographs. Vegetation-fluvial interactions varied with plant characteristics, river hydraulics and sediment conditions, across the wide range of scales we investigated. In the flume studies, tamarisk's denser crowns and stiffer stems induced greater sedimentation compared to cottonwood. This resulted in tamarisk's greater mortality from burial as small seedlings under sediment equilibrium conditions but higher relative survival in larger floods under sediment deficit scenarios, in which more cottonwoods were lost to root scour. Sediment deficit conditions, as occurs downstream of dams, induced both greater scour and greater plant loss. With larger size and at higher densities, plants' vulnerability diminished due to greater root anchoring and canopy effects on hydraulics. At the corridor scale, we observed a pattern of plant encroachment during five decades of flow regulation, in which channel narrowing and simplification was more associated with tamarisk-dominated reaches compared with native woodlands. Together, these multi-scale plant-river dynamics help explain the persistence of tamarisk along regulated rivers where catastrophic floods have been reduced and also highlight limitations of using flow releases for invasive species management.

  14. Planting sites in the Northeast

    Treesearch

    Northeastern Forest Experiment Station

    1961-01-01

    Tree planting involves many considerations - site classification, selection of species, planting practices, and protection from fire, insects, and diseases. The information about many of these aspects of planting is scattered and fragmentary.

  15. Tree planting in the Allegheny section

    Treesearch

    Northeastern Forest Experiment Station

    1961-01-01

    Tree planting involves many considerations - site classification, selection of species, planting practices, and protection from fire, insects, and diseases. The information about many of these aspects of planting is scattered and fragmentary.

  16. 76 FR 388 - Southern Nuclear Operating Company; Vogtle Electric Generating Plant, Unit Nos. 1 and 2; Notice...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-04

    ... Design,'' GDC 31, ``Fracture Prevention of Reactor Coolant Pressure Boundary,'' and GDC 32, ``Inspection... Operating Company; Vogtle Electric Generating Plant, Unit Nos. 1 and 2; Notice of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant Hazards Consideration...

  17. Simplification of the time-dependent generalized self-interaction correction method using two sets of orbitals: Application of the optimized effective potential formalism

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

    Messud, J.; Dinh, P. M.; Suraud, Eric

    2009-10-15

    We propose a simplification of the time-dependent self-interaction correction (TD-SIC) method using two sets of orbitals, applying the optimized effective potential (OEP) method. The resulting scheme is called time-dependent 'generalized SIC-OEP'. A straightforward approximation, using the spatial localization of one set of orbitals, leads to the 'generalized SIC-Slater' formalism. We show that it represents a great improvement compared to the traditional SIC-Slater and Krieger-Li-Iafrate formalisms.

  18. Simplification of the time-dependent generalized self-interaction correction method using two sets of orbitals: Application of the optimized effective potential formalism

    NASA Astrophysics Data System (ADS)

    Messud, J.; Dinh, P. M.; Reinhard, P.-G.; Suraud, Eric

    2009-10-01

    We propose a simplification of the time-dependent self-interaction correction (TD-SIC) method using two sets of orbitals, applying the optimized effective potential (OEP) method. The resulting scheme is called time-dependent “generalized SIC-OEP.” A straightforward approximation, using the spatial localization of one set of orbitals, leads to the “generalized SIC-Slater” formalism. We show that it represents a great improvement compared to the traditional SIC-Slater and Krieger-Li-Iafrate formalisms.

  19. A Role for APETALA1/FRUITFULL Transcription Factors in Tomato Leaf Development[C][W

    PubMed Central

    Burko, Yogev; Shleizer-Burko, Sharona; Yanai, Osnat; Shwartz, Ido; Zelnik, Iris Daphne; Jacob-Hirsch, Jasmine; Kela, Itai; Eshed-Williams, Leor; Ori, Naomi

    2013-01-01

    Flexible maturation rates underlie part of the diversity of leaf shape, and tomato (Solanum lycopersicum) leaves are compound due to prolonged organogenic activity of the leaf margin. The CINCINNATA -TEOSINTE BRANCHED1, CYCLOIDEA, PCF (CIN-TCP) transcription factor LANCEOLATE (LA) restricts this organogenic activity and promotes maturation. Here, we show that tomato APETALA1/FRUITFULL (AP1/FUL) MADS box genes are involved in tomato leaf development and are repressed by LA. AP1/FUL expression is correlated negatively with LA activity and positively with the organogenic activity of the leaf margin. LA binds to the promoters of the AP1/FUL genes MBP20 and TM4. Overexpression of MBP20 suppressed the simple-leaf phenotype resulting from upregulation of LA activity or from downregulation of class I knotted like homeobox (KNOXI) activity. Overexpression of a dominant-negative form of MBP20 led to leaf simplification and partly suppressed the increased leaf complexity of plants with reduced LA activity or increased KNOXI activity. Tomato plants overexpressing miR319, a negative regulator of several CIN-TCP genes including LA, flower with fewer leaves via an SFT-dependent pathway, suggesting that miR319-sensitive CIN-TCPs delay flowering in tomato. These results identify a role for AP1/FUL genes in vegetative development and show that leaf and plant maturation are regulated via partially independent mechanisms. PMID:23771895

  20. A role for APETALA1/fruitfull transcription factors in tomato leaf development.

    PubMed

    Burko, Yogev; Shleizer-Burko, Sharona; Yanai, Osnat; Shwartz, Ido; Zelnik, Iris Daphne; Jacob-Hirsch, Jasmine; Kela, Itai; Eshed-Williams, Leor; Ori, Naomi

    2013-06-01

    Flexible maturation rates underlie part of the diversity of leaf shape, and tomato (Solanum lycopersicum) leaves are compound due to prolonged organogenic activity of the leaf margin. The CINCINNATA-teosinte branched1, cycloidea, PCF (CIN-TCP) transcription factor lanceolate (LA) restricts this organogenic activity and promotes maturation. Here, we show that tomato APETALA1/fruitfull (AP1/FUL) MADS box genes are involved in tomato leaf development and are repressed by LA. AP1/FUL expression is correlated negatively with LA activity and positively with the organogenic activity of the leaf margin. LA binds to the promoters of the AP1/FUL genes MBP20 and TM4. Overexpression of MBP20 suppressed the simple-leaf phenotype resulting from upregulation of LA activity or from downregulation of class I knotted like homeobox (KNOXI) activity. Overexpression of a dominant-negative form of MBP20 led to leaf simplification and partly suppressed the increased leaf complexity of plants with reduced LA activity or increased KNOXI activity. Tomato plants overexpressing miR319, a negative regulator of several CIN-TCP genes including LA, flower with fewer leaves via an SFT-dependent pathway, suggesting that miR319-sensitive CIN-TCPs delay flowering in tomato. These results identify a role for AP1/FUL genes in vegetative development and show that leaf and plant maturation are regulated via partially independent mechanisms.

  1. Tropical forest loss and its multitrophic effects on insect herbivory.

    PubMed

    Morante-Filho, José Carlos; Arroyo-Rodríguez, Víctor; Lohbeck, Madelon; Tscharntke, Teja; Faria, Deborah

    2016-12-01

    Forest loss threatens biodiversity, but its potential effects on multitrophic ecological interactions are poorly understood. Insect herbivory depends on complex bottom-up (e.g., resource availability and plant antiherbivore defenses) and top-down forces (e.g., abundance of predators and herbivorous), but its determinants in human-altered tropical landscapes are largely unknown. Using structural equation models, we assessed the direct and indirect effects of forest loss on insect herbivory in 40 landscapes (115 ha each) from two regions with contrasting land-use change trajectories in the Brazilian Atlantic rainforest. We considered landscape forest cover as an exogenous predictor and (1) forest structure, (2) abundance of predators (birds and arthropods), and (3) abundance of herbivorous arthropods as endogenous predictors of insect leaf damage. From 12 predicted pathways, 11 were significant and showed that (1) leaf damage increases with forest loss (direct effect); (2) leaf damage increases with forest loss through the simplification of vegetation structure and its associated dominance of herbivorous insects (indirect effect); and further demonstrate (3) a lack of top-down control of herbivores by predators (birds and arthropods). We conclude that forest loss favors insect herbivory by undermining the bottom-up control (presumably reduced plant antiherbivore defense mechanisms) in forests dominated by fast-growing pioneer plant species, and by improving the conditions required for herbivores proliferation. © 2016 by the Ecological Society of America.

  2. A simple analytical method for determining the atmospheric dispersion of upward-directed high velocity releases

    NASA Astrophysics Data System (ADS)

    Palazzi, E.

    The evaluation of atmospheric dispersion of a cloud, arising from a sudden release of flammable or toxic materials, is an essential tool for properly designing flares, vents and other safety devices and to quantify the potential risk related to the existing ones or arising from the various kinds of accidents which can occur in chemical plants. Among the methods developed to treat the important case of upward-directed jets, Hoehne's procedure for determining the behaviour and extent of flammability zone is extensively utilized, particularly concerning petrochemical plants. In a previous study, a substantial simplification of the aforesaid procedure was achieved, by correlating the experimental data with an empirical formula, allowing to obtain a mathematical description of the boundaries of the flammable cloud. Following a theoretical approach, a most general model is developed in the present work, applicable to the various kinds of design problems and/or risk evaluation regarding upward-directed releases from high velocity sources. It is also demonstrated that the model gives conservative results, if applied outside the range of the Hoehne's experimental conditions. Moreover, with simple modifications, the same approach could be easily applied to deal with the atmospheric dispersion of anyhow directed releases.

  3. Next-generation purex flowsheets with acetohydroxamic acid as complexant for FBR and thermal-fuel reprocessing

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

    Kumar, Shekhar; Koganti, S.B.

    2008-07-01

    Acetohydroxamic acid (AHA) is a novel complexant for recycle of nuclear-fuel materials. It can be used in ordinary centrifugal extractors, eliminating the need for electro-redox equipment or complex maintenance requirements in a remotely maintained hot cell. In this work, the effect of AHA on Pu(IV) distribution ratios in 30% TBP system was quantified, modeled, and integrated in SIMPSEX code. Two sets of batch experiments involving macro Pu concentrations (conducted at IGCAR) and one high-Pu flowsheet (literature) were simulated for AHA based U-Pu separation. Based on the simulation and validation results, AHA based next-generation reprocessing flowsheets are proposed for co-processing basedmore » FBR and thermal-fuel reprocessing as well as evaporator-less macro-level Pu concentration process required for MOX fuel fabrication. Utilization of AHA results in significant simplification in plant design and simpler technology implementations with significant cost savings. (authors)« less

  4. 7 CFR 330.202 - Consideration of applications for permits to move plant pests.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... plant pests. 330.202 Section 330.202 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FEDERAL PLANT PEST REGULATIONS; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant Pests § 330.202...

  5. Structural considerations for underground nuclear power plants

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

    Sarne, Y.

    The advantages and disadvantages of underground nuclear power plants are briefly reviewed. The impact of underground contruction on plant layout and structural design are discussed. Schedules and costs for construction are compared with those for conventional plants.

  6. Plants get sick too!

    USDA-ARS?s Scientific Manuscript database

    Although many people may never have given consideration to plant health, plants can suffer from a wide range of diseases. These plant diseases are caused by micro-organisms, including bacteria, fungi, and viruses. The audience will be introduced to short case studies of several plant diseases that m...

  7. EMU processing - A myth dispelled

    NASA Technical Reports Server (NTRS)

    Peacock, Paul R.; Wilde, Richard C.; Lutz, Glenn C.; Melgares, Michael A.

    1991-01-01

    The refurbishment-and-checkout 'processing' activities entailed by the Space Shuttle Extravehicular Mobility Units (EMUs) are currently significantly more modest, at 1050 man-hours, than when Space Shuttle services began (involving about 4000 man-hours). This great improvement in hardware efficiency is due to the design or modification of test rigs for simplification of procedures, as well as those procedures' standardization, in conjunction with an increase in hardware confidence which has allowed the extension of inspection, service, and testing intervals. Recent simplification of the hardware-processing sequence could reduce EMU processing requirements to 600 man-hours in the near future.

  8. Parasitism by Cuscuta pentagona attenuates host plant defenses against insect herbivores

    Treesearch

    Justin B. Runyon; Mark C. Mescher; Consuelo M. De Moraes

    2008-01-01

    Considerable research has examined plant responses to concurrent attack by herbivores and pathogens, but the effects of attack by parasitic plants, another important class of plant-feeding organisms, on plant defenses against other enemies has not been explored. We investigated how attack by the parasitic plant Cuscuta pentagona impacted tomato (

  9. Four-trophic level food webs reveal the cascading impacts of an invasive plant targeted for biocontrol.

    PubMed

    López-Núñez, Francisco A; Heleno, Ruben H; Ribeiro, Sérgio; Marchante, Hélia; Marchante, Elizabete

    2017-03-01

    Biological invasions are a major threat to biodiversity and as such understanding their impacts is a research priority. Ecological networks provide a valuable tool to explore such impacts at the community level, and can be particularly insightful for planning and monitoring biocontrol programmes, including the potential for their seldom evaluated indirect non-target effects. Acacia longifolia is among the worst invasive species in Portugal, and has been recently targeted for biocontrol by a highly specific gall-wasp. Here we use an ambitious replicated network approach to: (1) identify the mechanisms by which direct and indirect impacts of A. longifolia can cascade from plants to higher trophic levels, including gallers, their parasitoids and inquilines; (2) reveal the structure of the interaction networks between plants, gallers, parasitoids and inquilines before the biocontrol; and (3) explore the potential for indirect interactions among gallers, including those established with the biocontrol agent, via apparent competition. Over a 15-month period, we collected 31,737 galls from native plants and identified all emerging insects, quantifying the interactions between 219 plant-, 49 galler-, 65 parasitoid- and 87 inquiline-species-one of the largest ecological networks to date. No galls were found on any of the 16 alien plant species. Invasion by A. longifolia caused an alarming simplification of plant communities, with cascading effects to higher trophic levels, namely: a decline of overall gall biomass, and on the richness, abundance and biomass of galler insects, their parasitoids, and inquilines. Correspondingly, we detected a significant decline in the richness of interactions between plants and galls. The invasion tended to increase overall interaction evenness by promoting the local extinction of the native plants that sustained more gall species. However, highly idiosyncratic responses hindered the detection of further consistent changes in network topology. Predictions of indirect effects of the biocontrol on native gallers via apparent competition ranged from negligible to highly significant. Such scenarios are incredibly hard to predict, but even if there are risks of indirect effects it is critical to weigh them carefully against the consequences of inaction and invasive species spread. © 2016 by the Ecological Society of America.

  10. Maximum performance of solar heat engines: Discussion of thermodynamic availability and other second law considerations and their implications

    NASA Astrophysics Data System (ADS)

    Boehm, R. F.

    1985-09-01

    A review of thermodynamic principles is given in an effort to see if these concepts may indicate possibilities for improvements in solar central receiver power plants. Aspects related to rate limitations in cycles, thermodynamic availability of solar radiation, and sink temperature considerations are noted. It appears that considerably higher instantaneous plant efficiencies are possible by raising the maximum temperature and lowering the minimum temperature of the cycles. Of course, many practical engineering problems will have to be solved to realize the promised benefits.

  11. What can we learn from Einstein and Arrhenius about the optimal flow of our blood?

    PubMed

    Schuster, Stefan; Stark, Heiko

    2014-01-01

    The oxygen flow in humans and other higher animals depends on the erythrocyte-to-blood volume ratio, the hematocrit. Since it is physiologically favourable when the flow of oxygen transport is maximum it can be assumed that this situation has been achieved during evolution. If the hematocrit was too low, too few erythrocytes could transport oxygen. If it was too high, the blood would be very viscous, so that oxygen supply would again be reduced. The theoretical optimal hematocrit can be calculated by considering the dependence of blood viscosity on the hematocrit. Different approaches to expressing this dependence have been proposed in the literature. Here, we discuss early approaches in hydrodynamics proposed by Einstein and Arrhenius and show that especially the Arrhenius equation is very appropriate for this purpose. We show that despite considerable simplifications such as neglecting the deformation, orientation and aggregation of erythrocytes, realistic hematocrit values of about 40% can be derived based on optimality considerations. Also the prediction that the ratio between the viscosities of the blood and blood plasma at high shear rates nearly equals Euler's constant (2.718) is in good agreement with observed values. Finally, we discuss possible extensions of the theory. For example, we derive the theoretical optimal hematocrit for persevering divers among marine mammals to be 65%, in excellent agreement with the values observed in several species. These considerations are very important for human and animal physiology since oxygen transport is an important factor for medicine and physical performance. © 2013 Elsevier B.V. All rights reserved.

  12. Wild Marshmallows.

    ERIC Educational Resources Information Center

    Kallas, John N.

    1984-01-01

    Provides information for teaching a unit on wild plants, including resources to use, plants to learn, safety considerations, list of plants (with scientific name, edible parts, and uses), list of plants that might cause allergic reactions when eaten. Also describes the chickweed, bull thistle, and common mallow. (BC)

  13. Simplification of Fatigue Test Requirements for Damage Tolerance of Composite Interstage Launch Vehicle Hardware

    NASA Technical Reports Server (NTRS)

    Nettles, A. T.; Hodge, A. J.; Jackson, J. R.

    2010-01-01

    The issue of fatigue loading of structures composed of composite materials is considered in a requirements document that is currently in place for manned launch vehicles. By taking into account the short life of these parts, coupled with design considerations, it is demonstrated that the necessary coupon level fatigue data collapse to a static case. Data from a literature review of past studies that examined compressive fatigue loading after impact and data generated from this experimental study are presented to support this finding. Damage growth, in the form of infrared thermography, was difficult to detect due to rapid degradation of compressive properties once damage growth initiated. Unrealistically high fatigue amplitudes were needed to fail 5 of 15 specimens before 10,000 cycles were reached. Since a typical vehicle structure, such as the Ares I interstage, only experiences a few cycles near limit load, it is concluded that static compression after impact (CAI) strength data will suffice for most launch vehicle structures.

  14. Waste Load Allocation for Conservative Substances to Protect Aquatic Organisms

    NASA Astrophysics Data System (ADS)

    Hutcheson, M. R.

    1992-01-01

    A waste load allocation process is developed to determine the maximum effluent concentration of a conservative substance that will not harm fish and wildlife propagation. If this concentration is not exceeded in the effluent, the acute toxicity criterion will not be violated in the receiving stream, and the chronic criterion will not be exceeded in the zone of passage, defined in many state water quality standards to allow the movement of aquatic organisms past a discharge. Considerable simplification of the concentration equation, which is the heart of any waste load allocation, is achieved because it is based on the concentration in the receiving stream when the concentration gradient on the zone of passage boundary is zero. Consequently, the expression obtained for effluent concentration is independent of source location or stream morphology. Only five independent variables, which are routinely available to regulatory agencies, are required to perform this allocation. It aids in developing permit limits which are protective without being unduly restrictive or requiring large expenditures of money and manpower on field investigations.

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

    Phillips, Benjamin R.; Baldridge, W. Scott; Gable, Carl W.

    Finite volume calculations of the flow of rhyolite are presented to investigate the fate of viscous magmas flowing in planar fractures with realistic length to width ratios of up to 2500:1. Heat and mass transfer for a melt with a temperature dependent viscosity and the potential to undergo phase change are considered. Magma driving pressures and dike widths are chosen to satisfy simple elastic considerations. These models are applied within a parameter space relevant to the Banco Bonito rhyolite flow, Valles caldera, New Mexico. We estimate a maximum eruption duration for the event of ~200 days, realized at a minimummore » possible dike width of 5-6 m and driving pressure of 7-8 MPa. Simplifications in the current model may warrant scaling of these results. However, we demonstrate the applicability of our model to magma dynamics issues and suggest that such models may be used to infer information about both the timing of an eruption and the evolution of the associated magma source.« less

  16. A note on generalized Genome Scan Meta-Analysis statistics

    PubMed Central

    Koziol, James A; Feng, Anne C

    2005-01-01

    Background Wise et al. introduced a rank-based statistical technique for meta-analysis of genome scans, the Genome Scan Meta-Analysis (GSMA) method. Levinson et al. recently described two generalizations of the GSMA statistic: (i) a weighted version of the GSMA statistic, so that different studies could be ascribed different weights for analysis; and (ii) an order statistic approach, reflecting the fact that a GSMA statistic can be computed for each chromosomal region or bin width across the various genome scan studies. Results We provide an Edgeworth approximation to the null distribution of the weighted GSMA statistic, and, we examine the limiting distribution of the GSMA statistics under the order statistic formulation, and quantify the relevance of the pairwise correlations of the GSMA statistics across different bins on this limiting distribution. We also remark on aggregate criteria and multiple testing for determining significance of GSMA results. Conclusion Theoretical considerations detailed herein can lead to clarification and simplification of testing criteria for generalizations of the GSMA statistic. PMID:15717930

  17. Metadata Sets for e-Government Resources: The Extended e-Government Metadata Schema (eGMS+)

    NASA Astrophysics Data System (ADS)

    Charalabidis, Yannis; Lampathaki, Fenareti; Askounis, Dimitris

    In the dawn of the Semantic Web era, metadata appear as a key enabler that assists management of the e-Government resources related to the provision of personalized, efficient and proactive services oriented towards the real citizens’ needs. As different authorities typically use different terms to describe their resources and publish them in various e-Government Registries that may enhance the access to and delivery of governmental knowledge, but also need to communicate seamlessly at a national and pan-European level, the need for a unified e-Government metadata standard emerges. This paper presents the creation of an ontology-based extended metadata set for e-Government Resources that embraces services, documents, XML Schemas, code lists, public bodies and information systems. Such a metadata set formalizes the exchange of information between portals and registries and assists the service transformation and simplification efforts, while it can be further taken into consideration when applying Web 2.0 techniques in e-Government.

  18. A Modeling Approach for Evaluating the Coupled Riparian Vegetation-Geomorphic Response to Altered Flow Regimes

    NASA Astrophysics Data System (ADS)

    Manners, R.; Wilcox, A. C.; Merritt, D. M.

    2016-12-01

    The ecogeomorphic response of riparian ecosystems to a change in hydrologic properties is difficult to predict because of the interactions and feedbacks among plants, water, and sediment. Most riparian models of community dynamics assume a static channel, yet geomorphic processes strongly control the establishment and survival of riparian vegetation. Using a combination of approaches that includes empirical relationships and hydrodynamic models, we model the coupled vegetation-topographic response of three cross-sections on the Yampa and Green Rivers in Dinosaur National Monument, to a shift in the flow regime. The locations represent the variable geomorphology and vegetation composition of these canyon-bound rivers. We account for the inundation and hydraulic properties of vegetation plots surveyed over three years within International River Interface Cooperative (iRIC) Fastmech, equipped with a vegetation module that accounts for flexible stems and plant reconfiguration. The presence of functional groupings of plants, or those plants that respond similarly to environmental factors such as water availability and disturbance are determined from flow response curves developed for the Yampa River. Using field measurements of vegetation morphology, distance from the channel centerline, and dominant particle size and modeled inundation properties we develop an empirical relationship between these variables and topographic change. We evaluate vegetation and channel form changes over decadal timescales, allowing for the integration of processes over time. From our analyses, we identify thresholds in the flow regime that alter the distribution of plants and reduce geomorphic complexity, predominately through side-channel and backwater infilling. Simplification of some processes (e.g., empirically-derived sedimentation) and detailed treatment of others (e.g., plant-flow interactions) allows us to model the coupled dynamics of riparian ecosystems and evaluate the impact of small to large shifts in the flow regime. This approach will be useful to river managers and scientists, as they try to understand the potential changes to riparian ecosystems with uncertain changes to hydrologic regimes as a result of a changing climate and human demands.

  19. Corrosion and stress corrosion cracking in supercritical water

    NASA Astrophysics Data System (ADS)

    Was, G. S.; Ampornrat, P.; Gupta, G.; Teysseyre, S.; West, E. A.; Allen, T. R.; Sridharan, K.; Tan, L.; Chen, Y.; Ren, X.; Pister, C.

    2007-09-01

    Supercritical water (SCW) has attracted increasing attention since SCW boiler power plants were implemented to increase the efficiency of fossil-based power plants. The SCW reactor (SCWR) design has been selected as one of the Generation IV reactor concepts because of its higher thermal efficiency and plant simplification as compared to current light water reactors (LWRs). Reactor operating conditions call for a core coolant temperature between 280 °C and 620 °C at a pressure of 25 MPa and maximum expected neutron damage levels to any replaceable or permanent core component of 15 dpa (thermal reactor design) and 100 dpa (fast reactor design). Irradiation-induced changes in microstructure (swelling, radiation-induced segregation (RIS), hardening, phase stability) and mechanical properties (strength, thermal and irradiation-induced creep, fatigue) are also major concerns. Throughout the core, corrosion, stress corrosion cracking, and the effect of irradiation on these degradation modes are critical issues. This paper reviews the current understanding of the response of candidate materials for SCWR systems, focusing on the corrosion and stress corrosion cracking response, and highlights the design trade-offs associated with certain alloy systems. Ferritic-martensitic steels generally have the best resistance to stress corrosion cracking, but suffer from the worst oxidation. Austenitic stainless steels and Ni-base alloys have better oxidation resistance but are more susceptible to stress corrosion cracking. The promise of grain boundary engineering and surface modification in addressing corrosion and stress corrosion cracking performance is discussed.

  20. Plant/life form considerations in the rangeland hydrology and erosion model (RHEM)

    USDA-ARS?s Scientific Manuscript database

    Resilience of rangeland to erosion has largely been attributed to adequate plant cover; however, plant life/growth form, and individual species presence can have a dramatic effect on hydrologic and erosion dynamics on rangelands. Plant life/growth form refers to genetic tendency of a plant to grow i...

  1. An adaptive controller for enhancing operator performance during teleoperation

    NASA Technical Reports Server (NTRS)

    Carignan, Craig R.; Tarrant, Janice M.; Mosier, Gary E.

    1989-01-01

    An adaptive controller is developed for adjusting robot arm parameters while manipulating payloads of unknown mass and inertia. The controller is tested experimentally in a master/slave configuration where the adaptive slave arm is commanded via human operator inputs from a master. Kinematically similar six-joint master and slave arms are used with the last three joints locked for simplification. After a brief initial adaptation period for the unloaded arm, the slave arm retrieves different size payloads and maneuvers them about the workspace. Comparisons are then drawn with similar tasks where the adaptation is turned off. Several simplifications of the controller dynamics are also addressed and experimentally verified.

  2. Video Vectorization via Tetrahedral Remeshing.

    PubMed

    Wang, Chuan; Zhu, Jie; Guo, Yanwen; Wang, Wenping

    2017-02-09

    We present a video vectorization method that generates a video in vector representation from an input video in raster representation. A vector-based video representation offers the benefits of vector graphics, such as compactness and scalability. The vector video we generate is represented by a simplified tetrahedral control mesh over the spatial-temporal video volume, with color attributes defined at the mesh vertices. We present novel techniques for simplification and subdivision of a tetrahedral mesh to achieve high simplification ratio while preserving features and ensuring color fidelity. From an input raster video, our method is capable of generating a compact video in vector representation that allows a faithful reconstruction with low reconstruction errors.

  3. 2D Electrostatic Potential Solver for Hall Thruster Simulation

    DTIC Science & Technology

    2006-07-12

    µ(jrBz − jzBr)Br − jrBθ) + µneEz + µ∇zp jr = µ(jzBθ − µ(jrBz − jzBr)Bz) + µneEr + µ∇rp (5) This equation system can be solved to isolate the axial and...Simplification The following simplifications are used to more easily manipulate the equation system . jz = Z3Ez + Z4Er + Z5 jr = R3Ez +R4Er +R5 (10) where, Z5...j−1 ∆r (18) With appropriate boundary conditions, a pentadiagonal linear system of equations of the form Ax=b can be constructed (where x is the

  4. Molecular simplification of 1,4-diazabicyclo[4.3.0]nonan-9-ones gives piperazine derivatives that maintain high nootropic activity.

    PubMed

    Manetti, D; Ghelardini, C; Bartolini, A; Dei, S; Galeotti, N; Gualtieri, F; Romanelli, M N; Teodori, E

    2000-11-16

    Several 4-substituted 1-acylpiperazines, obtained by molecular simplification of 4-substituted 1,4-diazabicyclo[4.3.0]nonan-9-ones, have been synthesized and tested in vivo on the mouse passive avoidance test, to evaluate their nootropic activity. The results show that, apparently, an N-acylpiperazine group can mimic the 2-pyrrolidinone ring of 1,4-diazabicyclo[4.3.0]nonan-9-one, as the compounds of the new series maintain high nootropic activity. Moreover molecular simplification produces more clear-cut structure-activity relationships with respect to the parent series. The mechanism of action also appears to be similar in the two series. In fact, although the molecular mechanism remains to be elucidated, the most potent compound of each class (DM232 and 13, DM235) is able to increase acetylcholine release in rat brain. Piperazine derivatives represent a new class of nootropic drugs with an in vivo pharmacological profile very similar to that of piracetam, showing much higher potency with respect to the reference compound. Among the compounds studied, 13 (DM235) shows outstanding potency, being active at a dose of 0.001 mg kg(-1) sc.

  5. A study of an alignment-less lithography method as an educational resource

    NASA Astrophysics Data System (ADS)

    Kai, Kazuho; Shiota, Koki; Nagaoka, Shiro; Mahmood, Mohamad Rusop Bin Haji; Kawai, Akira

    2016-07-01

    A simplification of the lithography process was studied. The simplification method of photolithography, named "alignment-less lithography" was proposed by omitting the photomask alignment process in photolithography process using mechanically aligned photomasks and substrate by using a simple jig on which countersinks were formed. Photomasks made of glass and the photomasks made of transparent plastic sheets were prepared for the process. As the result, approximately 5µm in the case of the glass mask, and 20µm in the case of the OHP mask were obtained with repetitive accuracies, respectively. It was confirmed that the alignment-less lithography method was successful. The possibility of the application to an educational program, such as a heuristic for solving problems was suggested using the method with the OHP mask. The nMOS FET fabrication process was successfully demonstrated using this method. The feasibility of this process was confirmed. It is expected that a totally simplified device fabrication process can be achievable when combined with other simplifications, such ass the simplified impurity diffusion processes using PSG and BSG thin film as diffusion source prepared by the Sol-Gel material under normal air environment.

  6. Shore Stabilization with Salt Marsh Vegetation.

    DTIC Science & Technology

    1983-01-01

    seedlings - more expensive to grow and plant, more awkward to handle and transport, but relatively easy to produce. (3) Plugs - most expensive to...to sprigs, particularly if trans- planted late in the growing season. Pot-grown seedlings are relatively easy to produce but considerably more...transplanted late in the growing season. Pot-grown seedlings are relatively easy to produce but considerably more expensive than sprigs (Fig. 25). To prepare

  7. A pan-European ring trial to validate an International Standard for detection of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus in seafoods.

    PubMed

    Hartnell, R E; Stockley, L; Keay, W; Rosec, J-P; Hervio-Heath, D; Van den Berg, H; Leoni, F; Ottaviani, D; Henigman, U; Denayer, S; Serbruyns, B; Georgsson, F; Krumova-Valcheva, G; Gyurova, E; Blanco, C; Copin, S; Strauch, E; Wieczorek, K; Lopatek, M; Britova, A; Hardouin, G; Lombard, B; In't Veld, P; Leclercq, A; Baker-Austin, C

    2018-02-10

    Globally, vibrios represent an important and well-established group of bacterial foodborne pathogens. The European Commission (EC) mandated the Comite de European Normalisation (CEN) to undertake work to provide validation data for 15 methods in microbiology to support EC legislation. As part of this mandated work programme, merging of ISO/TS 21872-1:2007, which specifies a horizontal method for the detection of V. parahaemolyticus and V. cholerae, and ISO/TS 21872-2:2007, a similar horizontal method for the detection of potentially pathogenic vibrios other than V. cholerae and V. parahaemolyticus was proposed. Both parts of ISO/TS 21872 utilized classical culture-based isolation techniques coupled with biochemical confirmation steps. The work also considered simplification of the biochemical confirmation steps. In addition, because of advances in molecular based methods for identification of human pathogenic Vibrio spp. classical and real-time PCR options were also included within the scope of the validation. These considerations formed the basis of a multi-laboratory validation study with the aim of improving the precision of this ISO technical specification and providing a single ISO standard method to enable detection of these important foodborne Vibrio spp.. To achieve this aim, an international validation study involving 13 laboratories from 9 countries in Europe was conducted in 2013. The results of this validation have enabled integration of the two existing technical specifications targeting the detection of the major foodborne Vibrio spp., simplification of the suite of recommended biochemical identification tests and the introduction of molecular procedures that provide both species level identification and discrimination of putatively pathogenic strains of V. parahaemolyticus by the determination of the presence of theromostable direct and direct related haemolysins. The method performance characteristics generated in this have been included in revised international standard, ISO 21872:2017, published in July 2017. Copyright © 2018. Published by Elsevier B.V.

  8. Plant cellulose synthesis: CESA proteins crossing kingdoms.

    PubMed

    Kumar, Manoj; Turner, Simon

    2015-04-01

    Cellulose is a biopolymer of considerable economic importance. It is synthesised by the cellulose synthase complex (CSC) in species ranging from bacteria to higher plants. Enormous progress in our understanding of bacterial cellulose synthesis has come with the recent publication of both the crystal structure and biochemical characterisation of a purified complex able to synthesis cellulose in vitro. A model structure of a plant CESA protein suggests considerable similarity between the bacterial and plant cellulose synthesis. In this review article we will cover current knowledge of how plant CESA proteins synthesise cellulose. In particular the focus will be on the lessons learned from the recent work on the catalytic mechanism and the implications that new data on cellulose structure has for the assembly of CESA proteins into the large complex that synthesis plant cellulose microfibrils. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Extending Data Worth Analyses to Select Multiple Observations Targeting Multiple Forecasts.

    PubMed

    Vilhelmsen, Troels N; Ferré, Ty P A

    2018-05-01

    Hydrological models are often set up to provide specific forecasts of interest. Owing to the inherent uncertainty in data used to derive model structure and used to constrain parameter variations, the model forecasts will be uncertain. Additional data collection is often performed to minimize this forecast uncertainty. Given our common financial restrictions, it is critical that we identify data with maximal information content with respect to forecast of interest. In practice, this often devolves to qualitative decisions based on expert opinion. However, there is no assurance that this will lead to optimal design, especially for complex hydrogeological problems. Specifically, these complexities include considerations of multiple forecasts, shared information among potential observations, information content of existing data, and the assumptions and simplifications underlying model construction. In the present study, we extend previous data worth analyses to include: simultaneous selection of multiple new measurements and consideration of multiple forecasts of interest. We show how the suggested approach can be used to optimize data collection. This can be used in a manner that suggests specific measurement sets or that produces probability maps indicating areas likely to be informative for specific forecasts. Moreover, we provide examples documenting that sequential measurement election approaches often lead to suboptimal designs and that estimates of data covariance should be included when selecting future measurement sets. © 2017, National Ground Water Association.

  10. Manual of Considerations and Techniques for Start-Up of Municipal Wastewater Treatment Facilities.

    ERIC Educational Resources Information Center

    Rader, R. D.; And Others

    This manual provides guidance for putting into initial operation a new municipal wastewater treatment plant, a new addition to an existing treatment plant, or a change in the mode of a treatment plant's operation. Information is provided on preparing for actual treatment plant start-up. Preparation for start-up includes: staffing the plant,…

  11. Safety of plant-made pharmaceuticals: product development and regulatory considerations based on case studies of two autologous human cancer vaccines.

    PubMed

    Tusé, Daniel

    2011-03-01

    Guidelines issued by regulatory agencies for the development of plant-made pharmaceutical (PMP) products provide criteria for product manufacturing and characterization, safety determination, containment and mitigation of environmental risks. Features of plant-made products do not always enable an easy fit within the criteria subscribed to by regulators. The unconventional nature of plant-based manufacturing processes and peculiarities of plant biology relative to that of traditional biological production systems have led to special considerations in the regulatory scrutiny of PMP. Presented in this review are case studies of two plant-made autologous (patient-specific) cancer vaccines, the nature of which introduced challenges to conventional and standardized development and preclinical evaluation routes. The rationale presented to FDA by the sponsors of each vaccine to build consensus and obtain variances to existing guidelines is discussed. While development of many plant-made biologics can be accomplished within the existing regulatory framework, the development of specialized products can be defended with rational arguments based on strong science.

  12. Turbomachinery design considerations for the nuclear HTGR-GT power plant

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

    McDonald, C.F.; Smith, M.J.

    1979-11-01

    For several years, design studies have been under way in the USA on a nuclear closed-cycle gas turbine plant (HTGR-GT). Design aspects of the helium turbomachine portion of these studies are presented. Gas dynamic and mechanical design considerations are presented for helium turbomachines in the 400-MW(e) (non-intercooled) and 600-MW(e) (intercooled) power range. Design of the turbomachine is a key element in the overall power plant program effort, which is currently directed toward the selection of a reference HTGR-GT commercial plant configuration for the US utility market. A conservative design approach has been emphasized to provide maximum safety and durability. Themore » studies presented for the integrated plant concept outline the necessary close working relationship between the reactor primary system and turbomachine designers.« less

  13. AP1000{sup R} design robustness against extreme external events - Seismic, flooding, and aircraft crash

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

    Pfister, A.; Goossen, C.; Coogler, K.

    2012-07-01

    Both the International Atomic Energy Agency (IAEA) and the U.S. Nuclear Regulatory Commission (NRC) require existing and new nuclear power plants to conduct plant assessments to demonstrate the unit's ability to withstand external hazards. The events that occurred at the Fukushima-Dai-ichi nuclear power station demonstrated the importance of designing a nuclear power plant with the ability to protect the plant against extreme external hazards. The innovative design of the AP1000{sup R} nuclear power plant provides unparalleled protection against catastrophic external events which can lead to extensive infrastructure damage and place the plant in an extended abnormal situation. The AP1000 plantmore » is an 1100-MWe pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance and safety. The plant's compact safety related footprint and protection provided by its robust nuclear island structures prevent significant damage to systems, structures, and components required to safely shutdown the plant and maintain core and spent fuel pool cooling and containment integrity following extreme external events. The AP1000 nuclear power plant has been extensively analyzed and reviewed to demonstrate that it's nuclear island design and plant layout provide protection against both design basis and extreme beyond design basis external hazards such as extreme seismic events, external flooding that exceeds the maximum probable flood limit, and malicious aircraft impact. The AP1000 nuclear power plant uses fail safe passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems (such as AC power, component cooling water, service water, compressed air or HVAC). The plant has been designed to protect systems, structures, and components critical to placing the reactor in a safe shutdown condition within the steel containment vessel which is further surrounded by a substantial 'steel concrete' composite shield building. The containment vessel is not affected by external flooding, and the shield building design provides hazard protection beyond that provided by a comparable reinforced concrete structure. The intent of this paper is to demonstrate the robustness of the AP1000 design against extreme events. The paper will focus on the plants ability to withstand extreme external events such as beyond design basis flooding, seismic events, and malicious aircraft impact. The paper will highlight the robustness of the AP1000 nuclear island design including the protection provided by the unique AP1000 composite shield building. (authors)« less

  14. Plant communities as drivers of soil respiration: pathways, mechanisms, and significance for global change

    NASA Astrophysics Data System (ADS)

    Metcalfe, D. B.; Fisher, R. A.; Wardle, D. A.

    2011-03-01

    Understanding the impacts of plant community characteristics on soil carbon dioxide efflux (R) is a key prerequisite for accurate prediction of the future carbon balance of terrestrial ecosystems under climate change. In this review, we synthesize relevant information from a wide spectrum of sources to evaluate the current state of knowledge about plant community effects on R, examine how this information is incorporated into global climate models, and highlight priorities for future research. Plant species consistently exhibit cohesive suites of traits, linked to contrasting life history strategies, which exert a variety of impacts on R. As such, we propose that plant community shifts towards dominance by fast growing plants with nutrient rich litter could provide a major, though often neglected, positive feedback to climate change. Within vegetation types, belowground carbon flux will mainly be controlled by photosynthesis, while amongst vegetation types this flux will be more dependent upon the specific characteristics of the plant life form. We also make the case that community composition, rather than diversity, is usually the dominant control on ecosystem processes in natural systems. Individual species impacts on R may be largest where the species accounts for most of the biomass in the ecosystem, has very distinct traits to the rest of the community, or modulates the occurrence of major natural disturbances. We show that climate-vegetation models incorporate a number of pathways whereby plants can affect R, but that simplifications regarding allocation schemes and drivers of litter decomposition may limit model accuracy. This situation could, however, be relatively easily improved with targeted experimental and field studies. Finally, we identify key gaps in knowledge and recommend them as priorities for future work. These include the patterns of photosynthate partitioning amongst belowground components, ecosystem level effects of individual plant traits, and the importance of trophic interactions and species invasions or extinctions for ecosystem processes. A final, overarching challenge is how to link these observations and drivers across spatio-temporal scales to predict regional or global changes in R over long time periods. A more unified approach to understanding R, which integrates information about plant traits and community dynamics, will be essential for better understanding, simulating and predicting feedbacks to R across terrestrial ecosystems and the earth-climate system.

  15. 7 CFR 330.202 - Consideration of applications for permits to move plant pests.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...; GENERAL; PLANT PESTS; SOIL, STONE, AND QUARRY PRODUCTS; GARBAGE Movement of Plant Pests § 330.202... Budget under control number 0579-0054) [24 FR 10825, Dec. 29, 1959, as amended at 48 FR 57466, Dec. 30...

  16. Method for making high-critical-current-density YBa.sub.2 Cu.sub.3 O.sub.7 superconducting layers on metallic substrates

    DOEpatents

    Feenstra, Roeland; Christen, David; Paranthaman, Mariappan

    1999-01-01

    A method is disclosed for fabricating YBa.sub.2 Cu.sub.3 O.sub.7 superconductor layers with the capability of carrying large superconducting currents on a metallic tape (substrate) supplied with a biaxially textured oxide buffer layer. The method represents a simplification of previously established techniques and provides processing requirements compatible with scale-up to long wire (tape) lengths and high processing speeds. This simplification has been realized by employing the BaF.sub.2 method to grow a YBa.sub.2 Cu.sub.3 O.sub.7 film on a metallic substrate having a biaxially textured oxide buffer layer.

  17. Intermediary LEO propagation including higher order zonal harmonics

    NASA Astrophysics Data System (ADS)

    Hautesserres, Denis; Lara, Martin

    2017-04-01

    Two new intermediary orbits of the artificial satellite problem are proposed. The analytical solutions include higher order effects of the geopotential, and are obtained by means of a torsion transformation applied to the quasi-Keplerian system resulting after the elimination of the parallax simplification, for the first intermediary, and after the elimination of the parallax and perigee simplifications, for the second one. The new intermediaries perform notably well for low Earth orbits propagation, are free from special functions, and result advantageous, both in accuracy and efficiency, when compared to the standard Cowell integration of the J_2 problem, thus providing appealing alternatives for onboard, short-term, orbit propagation under limited computational resources.

  18. Simplification of the Kalman filter for meteorological data assimilation

    NASA Technical Reports Server (NTRS)

    Dee, Dick P.

    1991-01-01

    The paper proposes a new statistical method of data assimilation that is based on a simplification of the Kalman filter equations. The forecast error covariance evolution is approximated simply by advecting the mass-error covariance field, deriving the remaining covariances geostrophically, and accounting for external model-error forcing only at the end of each forecast cycle. This greatly reduces the cost of computation of the forecast error covariance. In simulations with a linear, one-dimensional shallow-water model and data generated artificially, the performance of the simplified filter is compared with that of the Kalman filter and the optimal interpolation (OI) method. The simplified filter produces analyses that are nearly optimal, and represents a significant improvement over OI.

  19. Status of the ITER Cryodistribution

    NASA Astrophysics Data System (ADS)

    Chang, H.-S.; Vaghela, H.; Patel, P.; Rizzato, A.; Cursan, M.; Henry, D.; Forgeas, A.; Grillot, D.; Sarkar, B.; Muralidhara, S.; Das, J.; Shukla, V.; Adler, E.

    2017-12-01

    Since the conceptual design of the ITER Cryodistribution many modifications have been applied due to both system optimization and improved knowledge of the clients’ requirements. Process optimizations in the Cryoplant resulted in component simplifications whereas increased heat load in some of the superconducting magnet systems required more complicated process configuration but also the removal of a cold box was possible due to component arrangement standardization. Another cold box, planned for redundancy, has been removed due to the Tokamak in-Cryostat piping layout modification. In this proceeding we will summarize the present design status and component configuration of the ITER Cryodistribution with all changes implemented which aim at process optimization and simplification as well as operational reliability, stability and flexibility.

  20. Evaluation of the three-dimensional parabolic flow computer program SHIP

    NASA Technical Reports Server (NTRS)

    Pan, Y. S.

    1978-01-01

    The three-dimensional parabolic flow program SHIP designed for predicting supersonic combustor flow fields is evaluated to determine its capabilities. The mathematical foundation and numerical procedure are reviewed; simplifications are pointed out and commented upon. The program is then evaluated numerically by applying it to several subsonic and supersonic, turbulent, reacting and nonreacting flow problems. Computational results are compared with available experimental or other analytical data. Good agreements are obtained when the simplifications on which the program is based are justified. Limitations of the program and the needs for improvement and extension are pointed out. The present three dimensional parabolic flow program appears to be potentially useful for the development of supersonic combustors.

  1. Seeding and planting upland oaks

    Treesearch

    1989-01-01

    Oaks can be planted or seeded in uplands to: (1) afforest old fields, strip-mined areas, or other areas devoid of trees, and (2) supplement natural reproduction within existing forests. Planting is usually more successful than direct seeding. But even under good conditions survival and growth of planted oak has been considerably poorer than with conifers and other...

  2. A Course on Operational Considerations in Wastewater Treatment Plant Design. Instructor's Manual.

    ERIC Educational Resources Information Center

    Cooper, John W.; And Others

    This manual contains 17 instructional units (sequenced to correspond to parallel chapters in a student's manual) focusing on upgrading the design of wastewater plant facilities and serving as a reference source for establishing criteria for upgrading wastewater treatment plants. The manual also furnishes information for modifying plant design to…

  3. Laser-optical methods for earlier diagnostics of plant and seed diseases in various habitant media taking into consideration anthropogenic and biological pollution

    NASA Astrophysics Data System (ADS)

    Lisker, Joseph S.; Dmitriev, Andrey P.

    1999-12-01

    By the method of the computer laser-optical photometry the investigation of the cereal stability for the various diseases taken into consideration the stability of tomato seeds to their interaction with the phytopathogenes and the phytotoxicity of microscopic fungi on the wheat seedlings was carried out. Original result for the investigation of optical-physiological characteristics of plants and seeds are shown.

  4. 7 CFR 1724.51 - Design requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... control house, seismic considerations, corrosion, grounding, protective relaying, and AC and DC auxiliary... plant including plant buildings, the generator step-up transformer, and the transmission switchyard at a...

  5. Plant immunity: unravelling the complexity of plant responses to biotic stresses.

    PubMed

    Miller, Robert Neil Gerard; Costa Alves, Gabriel Sergio; Van Sluys, Marie-Anne

    2017-03-01

    Plants are constantly exposed to evolving pathogens and pests, with crop losses representing a considerable threat to global food security. As pathogen evolution can overcome disease resistance that is conferred by individual plant resistance genes, an enhanced understanding of the plant immune system is necessary for the long-term development of effective disease management strategies. Current research is rapidly advancing our understanding of the plant innate immune system, with this multidisciplinary subject area reflected in the content of the 18 papers in this Special Issue. Advances in specific areas of plant innate immunity are highlighted in this issue, with focus on molecular interactions occurring between plant hosts and viruses, bacteria, phytoplasmas, oomycetes, fungi, nematodes and insect pests. We provide a focus on research across multiple areas related to pathogen sensing and plant immune response. Topics covered are categorized as follows: binding proteins in plant immunity; cytokinin phytohormones in plant growth and immunity; plant-virus interactions; plant-phytoplasma interactions; plant-fungus interactions; plant-nematode interactions; plant immunity in Citrus; plant peptides and volatiles; and assimilate dynamics in source/sink metabolism. Although knowledge of the plant immune system remains incomplete, the considerable ongoing scientific progress into pathogen sensing and plant immune response mechanisms suggests far reaching implications for the development of durable disease resistance against pathogens and pests. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  6. Influence of different computational approaches for stent deployment on cerebral aneurysm haemodynamics

    PubMed Central

    Bernardini, Annarita; Larrabide, Ignacio; Morales, Hernán G.; Pennati, Giancarlo; Petrini, Lorenza; Cito, Salvatore; Frangi, Alejandro F.

    2011-01-01

    Cerebral aneurysms are abnormal focal dilatations of artery walls. The interest in virtual tools to help clinicians to value the effectiveness of different procedures for cerebral aneurysm treatment is constantly growing. This study is focused on the analysis of the influence of different stent deployment approaches on intra-aneurysmal haemodynamics using computational fluid dynamics (CFD). A self-expanding stent was deployed in an idealized aneurysmatic cerebral vessel in two initial positions. Different cases characterized by a progression of simplifications on stent modelling (geometry and material) and vessel material properties were set up, using finite element and fast virtual stenting methods. Then, CFD analysis was performed for untreated and stented vessels. Haemodynamic parameters were analysed qualitatively and quantitatively, comparing the cases and the two initial positions. All the cases predicted a reduction of average wall shear stress and average velocity of almost 50 per cent after stent deployment for both initial positions. Results highlighted that, although some differences in calculated parameters existed across the cases based on the modelling simplifications, all the approaches described the most important effects on intra-aneurysmal haemodynamics. Hence, simpler and faster modelling approaches could be included in clinical workflow and, despite the adopted simplifications, support clinicians in the treatment planning. PMID:22670204

  7. A "Kane's Dynamics" Model for the Active Rack Isolation System Part Two: Nonlinear Model Development, Verification, and Simplification

    NASA Technical Reports Server (NTRS)

    Beech, G. S.; Hampton, R. D.; Rupert, J. K.

    2004-01-01

    Many microgravity space-science experiments require vibratory acceleration levels that are unachievable without active isolation. The Boeing Corporation's active rack isolation system (ARIS) employs a novel combination of magnetic actuation and mechanical linkages to address these isolation requirements on the International Space Station. Effective model-based vibration isolation requires: (1) An isolation device, (2) an adequate dynamic; i.e., mathematical, model of that isolator, and (3) a suitable, corresponding controller. This Technical Memorandum documents the validation of that high-fidelity dynamic model of ARIS. The verification of this dynamics model was achieved by utilizing two commercial off-the-shelf (COTS) software tools: Deneb's ENVISION(registered trademark), and Online Dynamics Autolev(trademark). ENVISION is a robotics software package developed for the automotive industry that employs three-dimensional computer-aided design models to facilitate both forward and inverse kinematics analyses. Autolev is a DOS-based interpreter designed, in general, to solve vector-based mathematical problems and specifically to solve dynamics problems using Kane's method. The simplification of this model was achieved using the small-angle theorem for the joint angle of the ARIS actuators. This simplification has a profound effect on the overall complexity of the closed-form solution while yielding a closed-form solution easily employed using COTS control hardware.

  8. Reasons for switching ART: Comparison of data collected in 2012-2013 and 2014-2015 in Florence, Italy.

    PubMed

    Fusco, Francesco Maria; Burla, Maria Chiara; Degli Esposti, Anna; Pierotti, Piera; Rabatti, Loredana; Vichi, Francesca

    2018-03-01

    Persons living with HIV should remain on antiretroviral therapy (ART) indefinitely; however, a switch in the drug regimen is often necessary. In order to investigate if reasons for switching ART changed over time, we retrospectively analyzed reasons for switching and characteristics of switches among patients at Santa Maria Annunziata Hospital (OSMA), Florence area, Tuscany, Italy, over two periods (November 2012-October 2013 and November 2014-October 2015). The reasons for switching were classified as: simplification; virologic failure; occurrence of co-morbidities; and drug tolerability/toxicity issues. In period 1 (2012-2013), 18% patients changed their regimen vs. 13.5% in period 2 (2014-2015) (p = 0.019). Among reasons for switching, switches for simplification significantly increased from 41% in period 1 to 53% in period 2 (p = 0.004), with an increasing use of single tablet regimens (p = 0.002); no other statistically significant differences were found in other reasons for switching in periods 1 and 2. Characteristics of patients and of switches were analyzed and described. According to our data, the main reason for switching is now simplification, reflecting the recent changes in recommendations aimed to enhance adherence and quality of life, and to minimize, at the same time, drug toxicity and side effects.

  9. Searching for simplicity in the analysis of neurons and behavior

    PubMed Central

    Stephens, Greg J.; Osborne, Leslie C.; Bialek, William

    2011-01-01

    What fascinates us about animal behavior is its richness and complexity, but understanding behavior and its neural basis requires a simpler description. Traditionally, simplification has been imposed by training animals to engage in a limited set of behaviors, by hand scoring behaviors into discrete classes, or by limiting the sensory experience of the organism. An alternative is to ask whether we can search through the dynamics of natural behaviors to find explicit evidence that these behaviors are simpler than they might have been. We review two mathematical approaches to simplification, dimensionality reduction and the maximum entropy method, and we draw on examples from different levels of biological organization, from the crawling behavior of Caenorhabditis elegans to the control of smooth pursuit eye movements in primates, and from the coding of natural scenes by networks of neurons in the retina to the rules of English spelling. In each case, we argue that the explicit search for simplicity uncovers new and unexpected features of the biological system and that the evidence for simplification gives us a language with which to phrase new questions for the next generation of experiments. The fact that similar mathematical structures succeed in taming the complexity of very different biological systems hints that there is something more general to be discovered. PMID:21383186

  10. Simplifiying global biogeochemistry models to evaluate methane emissions

    NASA Astrophysics Data System (ADS)

    Gerber, S.; Alonso-Contes, C.

    2017-12-01

    Process-based models are important tools to quantify wetland methane emissions, particularly also under climate change scenarios, evaluating these models is often cumbersome as they are embedded in larger land-surface models where fluctuating water table and the carbon cycle (including new readily decomposable plant material) are predicted variables. Here, we build on these large scale models but instead of modeling water table and plant productivity we provide values as boundary conditions. In contrast, aerobic and anaerobic decomposition, as well as soil column transport of oxygen and methane are predicted by the model. Because of these simplifications, the model has the potential to be more readily adaptable to the analysis of field-scale data. Here we determine the sensitivity of the model to specific setups, parameter choices, and to boundary conditions in order to determine set-up needs and inform what critical auxiliary variables need to be measured in order to better predict field-scale methane emissions from wetland soils. To that end we performed a global sensitivity analysis that also considers non-linear interactions between processes. The global sensitivity analysis revealed, not surprisingly, that water table dynamics (both mean level and amplitude of fluctuations), and the rate of the carbon cycle (i.e. net primary productivity) are critical determinants of methane emissions. The depth-scale where most of the potential decomposition occurs also affects methane emissions. Different transport mechanisms are compensating each other to some degree: If plant conduits are constrained, methane emissions by diffusive flux and ebullition compensate to some degree, however annual emissions are higher when plants help to bypass methanotrophs in temporally unsaturated upper layers. Finally, while oxygen consumption by plant roots help creating anoxic conditions it has little effect on overall methane emission. Our initial sensitivity analysis helps guiding further model development and improvement. However, an important goal for our model is to use it in field settings as a tool to deconvolve the different processes that contribute to the net transfer of methane from soils to atmosphere.

  11. A full three dimensional Navier-Stokes numerical simulation of flow field inside a power plant Kaplan turbine using some model test turbine hill chart points

    NASA Astrophysics Data System (ADS)

    Hosseinalipour, S. M.; Raja, A.; Hajikhani, S.

    2012-06-01

    A full three dimensional Navier - Stokes numerical simulation has been performed for performance analysis of a Kaplan turbine which is installed in one of the Irans south dams. No simplifications have been enforced in the simulation. The numerical results have been evaluated using some integral parameters such as the turbine efficiency via comparing the results with existing experimental data from the prototype Hill chart. In part of this study the numerical simulations were performed in order to calculate the prototype turbine efficiencies in some specific points which comes from the scaling up of the model efficiency that are available in the model experimental Hill chart. The results are very promising which shows the good ability of the numerical techniques for resolving the flow characteristics in these kind of complex geometries. A parametric study regarding the evaluation of turbine performance in three different runner angles of the prototype is also performed and the results are cited in this paper.

  12. Patient perspectives on de-simplifying their single-tablet co-formulated antiretroviral therapy for societal cost savings.

    PubMed

    Krentz, H B; Campbell, S; Gill, V C; Gill, M J

    2018-04-01

    The incremental costs of expanding antiretroviral (ARV) drug treatment to all HIV-infected patients are substantial, so cost-saving initiatives are important. Our objectives were to determine the acceptability and financial impact of de-simplifying (i.e. switching) more expensive single-tablet formulations (STFs) to less expensive generic-based multi-tablet components. We determined physician and patient perceptions and acceptance of STF de-simplification within the context of a publicly funded ARV budget. Programme costs were calculated for patients on ARVs followed at the Southern Alberta Clinic, Canada during 2016 (Cdn$). We focused on patients receiving Triumeq® and determined the savings if patients de-simplified to eligible generic co-formulations. We surveyed all prescribing physicians and a convenience sample of patients taking Triumeq® to see if, for budgetary purposes, they felt that de-simplification would be acceptable. Of 1780 patients receiving ARVs, 62% (n = 1038) were on STF; 58% (n = 607) of patients on STF were on Triumeq®. The total annual cost of ARVs was $26 222 760. The cost for Triumeq® was $8 292 600. If every patient on Triumeq® switched to generic abacavir/lamivudine and Tivicay® (dolutegravir), total costs would decrease by $4 325 040. All physicians (n = 13) felt that de-simplifying could be safely achieved. Forty-eight per cent of 221 patients surveyed were agreeable to de-simplifying for altruistic reasons, 27% said no, and 25% said maybe. De-simplifying Triumeq® generates large cost savings. Additional savings could be achieved by de-simplifying other STFs. Both physicians and patients agreed that selective de-simplification was acceptable; however, it may not be acceptable to every patient. Monitoring the medical and cost impacts of de-simplification strategies seems warranted. © 2018 British HIV Association.

  13. Regio- and stereoselectivities in plant cell biotransformation

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

    Hamada, H.

    1995-12-01

    The ability of plant cultured cells to convert foreign substrates into more useful substances is of considerable interest. Therefore I have studied biotransformation of foreign substrate by plant cell suspension cultures. In this presentation, I report regio- and stereoselectivities in biotransformation of steroids and indole alkaloids and taxol by plant (tobacco, periwinkle, moss, orchid) cell suspension cultures.

  14. A Course on Operational Considerations in Wastewater Treatment Plant Design. Student Manual.

    ERIC Educational Resources Information Center

    Stottler, Stag and Associates, San Antonio, TX.

    This manual was designed to furnish information for upgrading the design of wastewater treatment plant facilities and to serve as a resource for establishing criteria for upgrading these plants. The manual also furnishes information for modifying plant design to compensate for current organic and hydraulic overloads and/or to meet more stringent…

  15. Three-way interaction among plants, bacteria, and coleopteran insects.

    PubMed

    Wielkopolan, Beata; Obrępalska-Stęplowska, Aleksandra

    2016-08-01

    Coleoptera, the largest and the most diverse Insecta order, is characterized by multiple adaptations to plant feeding. Insect-associated microorganisms can be important mediators and modulators of interactions between insects and plants. Interactions between plants and insects are highly complex and involve multiple factors. There are various defense mechanisms initiated by plants upon attack by herbivorous insects, including the development of morphological structures and the synthesis of toxic secondary metabolites and volatiles. In turn, herbivores have adapted to feeding on plants and further sophisticated adaptations to overcome plant responses may continue to evolve. Herbivorous insects may detoxify toxic phytocompounds, sequester poisonous plant factors, and alter their own overall gene expression pattern. Moreover, insects are associated with microbes, which not only considerably affect insects, but can also modify plant defense responses to the benefit of their host. Plants are also frequently associated with endophytes, which may act as bioinsecticides. Therefore, it is very important to consider the factors influencing the interaction between plants and insects. Herbivorous insects cause considerable damage to global crop production. Coleoptera is the largest and the most diverse order in the class Insecta. In this review, various aspects of the interactions among insects, microbes, and plants are described with a focus on coleopteran species, their bacterial symbionts, and their plant hosts to demonstrate that many factors contribute to the success of coleopteran herbivory.

  16. Transformation of soil and vegetable conditions at oil production territories

    NASA Astrophysics Data System (ADS)

    Gatina, Evgeniia

    2017-04-01

    On the territory of modern oil production soil, vegetation, ecosystem conditions of the environment are significantly transformed. Researches have been conducted on the oil production territories located in a boreal coniferous forest natural zone from 2005 to 2015. Standard geobotanical and soil methods are used. Mechanical destruction of a plant cover, change of the water conditions, intake of oil products and salty waters in ecosystems, pollution of the atmosphere are considered as the major technology-related factors defining transformation of land ecosystems at operation of the oil field. Under the mechanical destruction of a plant cover the pioneer plant communities are formed. These communities are characterized by most reduced specific wealth with prevalence of types of meadow groups of plants and presence of types of wetland groups of plants. The biodiversity of biocenosis which are affected linear infrastructure facilities of oil production territories and change of the water conditions, decreases. It is observed decrease in species wealth, simplification of structure of communities. Under the salting of soils in ecosystems there is a decrease species diversity of communities to prevalence nitrophilous and meadow plant species. At the increased content of organic substances in the soils that is a consequence of intake of oil products, is characteristic increase in specific richness of communities, introduction of types of wetland and oligotrophic groups of plants in forest communities. Influence depends on distance to an influence source. In process of removal from a source of atmospheric pollution in forest communities there is a decrease in species diversity and complication of structure of community. It is caused by introduction of types of meadow groups of plants in ecotone sites of the forest communities located near a source of influence and restoration of structural features of forest communities in process of removal from an influence source. Operation of oil fields leads to introduction of the synanthropes relating to meadow and wetland groups of plants. Transformation depends on loading time. At the initial stage of operation of the oil field the synantropization of a plant cover leads to increase in species diversity. At long technogenic loading decrease in values of indexes of a biodiversity due to oppression of native species of plants is observed. Technology-related influence of oil fields is a regional factor of change of specific structure of plant communities. Modern oil production has to be followed by purposeful formation of the operated natural and technology-related ecosystems with adjustable parameters and higher stability in relation to a complex of technogenic oil-field influence.

  17. Characterization of calcium oxalate defective (cod) 3 mutant from Medicago truncatula

    USDA-ARS?s Scientific Manuscript database

    Many plants invest a considerable amount of resources and energy into the formation of calcium oxalate crystals. Assigned roles for plant crystal formation include functions in defense, calcium regulation, and aluminum tolerance. From a human health standpoint, oxalate present in edible plant tiss...

  18. Microwave Processing of Crowns from Winter Cereals for Light Microscopy.

    USDA-ARS?s Scientific Manuscript database

    Microwave processing of tissue considerably shortens the time it takes to prepare samples for light and electron microscopy. However, plant tissues from different species and different regions of the plant respond differently making it impossible to use a single protocol for all plant tissue. The ...

  19. The Council of Psychological Advisers.

    PubMed

    Sunstein, Cass R

    2016-01-01

    Findings in behavioral science, including psychology, have influenced policies and reforms in many nations. Choice architecture can affect outcomes even if material incentives are not involved. In some contexts, default rules, simplification, and social norms have had even larger effects than significant economic incentives. Psychological research is helping to inform initiatives in savings, finance, highway safety, consumer protection, energy, climate change, obesity, education, poverty, development, crime, corruption, health, and the environment. No nation has yet created a council of psychological advisers, but the role of behavioral research in policy domains is likely to grow in the coming years, especially in light of the mounting interest in promoting ease and simplification ("navigability"); in increasing effectiveness, economic growth, and competitiveness; and in providing low-cost, choice-preserving approaches.

  20. Simplification of a dust emission scheme and comparison with data

    NASA Astrophysics Data System (ADS)

    Shao, Yaping

    2004-05-01

    A simplification of a dust emission scheme is proposed, which takes into account of saltation bombardment and aggregates disintegration. The statement of the scheme is that dust emission is proportional to streamwise saltation flux, but the proportionality depends on soil texture and soil plastic pressure p. For small p values (loose soils), dust emission rate is proportional to u*4 (u* is friction velocity) but not necessarily so in general. The dust emission predictions using the scheme are compared with several data sets published in the literature. The comparison enables the estimate of a model parameter and soil plastic pressure for various soils. While more data are needed for further verification, a general guideline for choosing model parameters is recommended.

  1. Collegiality and commerce: The culture of consideration amongst engineers

    NASA Astrophysics Data System (ADS)

    Nugent, Paul David

    This study is a participant observation ethnography of engineering relationships at a defense contracting plant that specializes in the design and manufacture of launch control systems for nuclear submarines. "Consideration" is presented as a unique mode of interaction enabling resource exchange and pivotal in developing and strengthening work relationships. Consideration differs from other modes of exchange such as markets, gift-giving, and charity primarily in that the bestowal of the resource involves little sacrifice. The manner in which consideration is enacted by the engineers, the structural and cultural conditions supporting consideration, and the social and economic consequences of consideration are presented. From these findings it is concluded that consideration is a unique form of economic exchange embedded in concrete relationships that forces us to rethink and extend current conceptualizations of trust, networks, social capital, and friendship in the workplace. The data for the analysis were drawn from twenty interviews and fieldnotes collected and transcribed over a twelve month period. Quotations from the interviews and exerpts from the fieldnotes are included to illustrate claims being made in the analysis as well as to familiarize the reader with the culture developed by engineers and managers in a defense contracting plant.

  2. Eco-geophysical imaging of watershed-scale soil patterns links with plant community spatial patterns

    USDA-ARS?s Scientific Manuscript database

    The extent to which soil resource availability, nutrients or 1 moisture, control the structure, function and diversity of plant communities has aroused considerable interest in the past decade, and remains topical in light of global change. Numerous plant communities are controlled either by water o...

  3. The School Custodian and Operation of the School Plant.

    ERIC Educational Resources Information Center

    Louisiana State Dept. of Education, Baton Rouge.

    Guidelines for school maintenance techniques and operational procedures in which consideration is given to the following aspects of school maintenance and operation--(1) importance and responsibilities of the school custodian, (2) custodial personnel policies, (3) housekeeping duties in the school plant, (4) cleaning restrooms in the school plant,…

  4. PLANNING THE ELEMENTARY SCHOOL PLANT. SCHOOL PLANT PLANNING SERIES.

    ERIC Educational Resources Information Center

    Utah State Board of Education, Salt Lake City.

    CAREFUL PLANNING FOR THE ELEMENTARY SCHOOL MAXIMIZES THE USE OF SPACE TO PROVIDE CHILDREN WITH FREQUENT CHANGES IN ACTIVITY AND A WIDE VARIETY OF EXPERIENCES. IN THE PLANNING PROCESS, SPECIAL CONSIDERATION IS GIVEN TO LONG RANGE DEVELOPMENT THUS PREVENTING OVERBUILDING AND UNDERBUILDING. THE PLANT SHOULD FIT, THROUGH INCREASING UTILITY BY…

  5. Regulation of Water in Plant Cells

    ERIC Educational Resources Information Center

    Kowles, Richard V.

    2010-01-01

    Cell water relationships are important topics to be included in cell biology courses. Differences exist in the control of water relationships in plant cells relative to control in animal cells. One important reason for these differences is that turgor pressure is a consideration in plant cells. Diffusion and osmosis are the underlying factors…

  6. Susceptibility of Australian plant species to Phytophthora ramorum

    Treesearch

    Kylie Ireland; Daniel H& uuml; berli; Bernard Dell; Ian Smith; David Rizzo; Giles Hardy

    2010-01-01

    Phytophthora ramorum is an invasive plant pathogen causing considerable and widespread damage in nurseries, gardens, and natural woodland ecosystems of the United States and Europe, and is classified as a Category 1 pest in Australia. It is of particular interest to Australian plant biosecurity as, like P. cinnamomi; it has...

  7. 7 CFR 352.10 - Inspection; safeguards; disposal.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... specified by him to prevent plant pest or noxious weed dissemination. In the case of prohibited or... commensurate with the risk of plant pest or noxious weed dissemination required to transfer the products or... of the inspector, considerations of risk of plant pest or noxious weed dissemination require, such...

  8. 7 CFR 352.10 - Inspection; safeguards; disposal.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... specified by him to prevent plant pest or noxious weed dissemination. In the case of prohibited or... commensurate with the risk of plant pest or noxious weed dissemination required to transfer the products or... of the inspector, considerations of risk of plant pest or noxious weed dissemination require, such...

  9. 7 CFR 352.10 - Inspection; safeguards; disposal.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... specified by him to prevent plant pest or noxious weed dissemination. In the case of prohibited or... commensurate with the risk of plant pest or noxious weed dissemination required to transfer the products or... of the inspector, considerations of risk of plant pest or noxious weed dissemination require, such...

  10. 7 CFR 352.10 - Inspection; safeguards; disposal.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... specified by him to prevent plant pest or noxious weed dissemination. In the case of prohibited or... commensurate with the risk of plant pest or noxious weed dissemination required to transfer the products or... of the inspector, considerations of risk of plant pest or noxious weed dissemination require, such...

  11. Metabolomic profiling of the nectars of Aquilegia pubescens and A. canadensis

    USDA-ARS?s Scientific Manuscript database

    To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the...

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

    Behnke, M. R.; Bellei, T.A.; Bloethe, W.G.

    This paper presents a summary of the most impor- tant considerations for wind power plant collection system un- derground and overhead cable designs. Various considerations, including conductor selection, soil thermal properties, installa- tion methods, splicing, concentric grounding, and NESC/NEC requirements are discussed.

  13. Intentionality, Degree of Damage, and Moral Judgments

    ERIC Educational Resources Information Center

    Berg-Cross, Linda Gail

    1975-01-01

    Piagetian moral judgment problems were simplified and tested on first grade children to ascertain whether the simplification would affect the subjects' perceptions of intentionality and punishment. (JMB)

  14. 17 CFR 200.1 - General statement and statutory authority.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... COMMISSION ORGANIZATION; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Organization and Program Management... company system simplification and integration; and approval of their reorganization, mergers and...

  15. Increasing Public Library Productivity.

    ERIC Educational Resources Information Center

    Samuelson, Howard

    1981-01-01

    Suggests ways of improving productivity for public libraries faced with increased accountability, dwindling revenues, and continuing inflation. Techniques described include work simplification, work analysis, improved management, and employee motivation. (RAA)

  16. System considerations favoring rotary artificial hearts with blood-immersed bearings.

    PubMed

    Jarvik, R K

    1995-07-01

    Hydrodynamic blood pumps provide such advantages as not requiring an air vent or compliance chamber as well as a great reduction in mechanical complexity with the potential for very long durability. The detailed design of their bearings is emerging as the single most important determinant of long-term success. Three categories of bearings include remote force, such as magnetic suspension; blood-isolated, which require a shaft seal; and blood-immersed using either mechanical or hydrodynamic support. Blood-immersed bearings permit maximum simplification and miniaturization of the entire system, require no flush fluid, and require no electronics as with magnetic suspension. The Jarvik 2000 heart represents an example of their potential. The intraventricular titanium pump (25 mm diameter, 25 cc, 85 g), uses blood flow through the motor air gap with blood-immersed bearings. The longest in vitro bearing durability test is ongoing at 20,000,000,000 revolutions with minimal wear (3 years at 15,000 rpm). In vivo results include 5-month calf survival, no thromboembolism, plasma Hb 2-5 mg%, and power under 10 W.

  17. 3D Visible-Light Invisibility Cloak.

    PubMed

    Zheng, Bin; Zhu, Rongrong; Jing, Liqiao; Yang, Yihao; Shen, Lian; Wang, Huaping; Wang, Zuojia; Zhang, Xianmin; Liu, Xu; Li, Erping; Chen, Hongsheng

    2018-06-01

    The concept of an invisibility cloak is a fixture of science fiction, fantasy, and the collective imagination. However, a real device that can hide an object from sight in visible light from absolutely any viewpoint would be extremely challenging to build. The main obstacle to creating such a cloak is the coupling of the electromagnetic components of light, which would necessitate the use of complex materials with specific permittivity and permeability tensors. Previous cloaking solutions have involved circumventing this obstacle by functioning either in static (or quasistatic) fields where these electromagnetic components are uncoupled or in diffusive light scattering media where complex materials are not required. In this paper, concealing a large-scale spherical object from human sight from three orthogonal directions is reported. This result is achieved by developing a 3D homogeneous polyhedral transformation and a spatially invariant refractive index discretization that considerably reduce the coupling of the electromagnetic components of visible light. This approach allows for a major simplification in the design of 3D invisibility cloaks, which can now be created at a large scale using homogeneous and isotropic materials.

  18. Parity in knot theory

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

    Manturov, Vassily O

    2010-06-29

    In this work we study knot theories with a parity property for crossings: every crossing is declared to be even or odd according to a certain preassigned rule. If this rule satisfies a set of simple axioms related to the Reidemeister moves, then certain simple invariants solving the minimality problem can be defined, and invariant maps on the set of knots can be constructed. The most important example of a knot theory with parity is the theory of virtual knots. Using the parity property arising from Gauss diagrams we show that even a gross simplification of the theory of virtualmore » knots, namely, the theory of free knots, admits simple and highly nontrivial invariants. This gives a solution to a problem of Turaev, who conjectured that all free knots are trivial. In this work we show that free knots are generally not invertible, and provide invariants which detect the invertibility of free knots. The passage to ordinary virtual knots allows us to strengthen known invariants (such as the Kauffman bracket) using parity considerations. We also discuss other examples of knot theories with parity. Bibliography: 27 items.« less

  19. [Simplification of crop shortage water index and its application in drought remote sensing monitoring].

    PubMed

    Liu, Anlin; Li, Xingmin; He, Yanbo; Deng, Fengdong

    2004-02-01

    Based on the principle of energy balance, the method for calculating latent evaporation was simplified, and hence, the construction of the drought remote sensing monitoring model of crop water shortage index was also simplified. Since the modified model involved fewer parameters and reduced computing times, it was more suitable for the operation running in the routine services. After collecting the concerned meteorological elements and the NOAA/AVHRR image data, the new model was applied to monitor the spring drought in Guanzhong, Shanxi Province. The results showed that the monitoring results from the new model, which also took more considerations of the effects of the ground coverage conditions and meteorological elements such as wind speed and the water pressure, were much better than the results from the model of vegetation water supply index. From the view of the computing times, service effects and monitoring results, the simplified crop water shortage index model was more suitable for practical use. In addition, the reasons of the abnormal results of CWSI > 1 in some regions in the case studies were also discussed in this paper.

  20. Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation.

    PubMed

    Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

    2018-05-04

    The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the ΔI=1 channel with the parity-odd pion-nucleon coupling constant h_{π}^{1}. Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating h_{π}^{1} and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the ΔI=1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of h_{π}^{1} by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of h_{π}^{1}, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

  1. RF-based power distribution system for optogenetic experiments

    NASA Astrophysics Data System (ADS)

    Filipek, Tomasz A.; Kasprowicz, Grzegorz H.

    2017-08-01

    In this paper, the wireless power distribution system for optogenetic experiment was demonstrated. The design and the analysis of the power transfer system development is described in details. The architecture is outlined in the context of performance requirements that had to be met. We show how to design a wireless power transfer system using resonant coupling circuits which consist of a number of receivers and one transmitter covering the entire cage area with a specific power density. The transmitter design with the full automated protection stage is described with detailed consideration of the specification and the construction of the transmitting loop antenna. In addition, the design of the receiver is described, including simplification of implementation and the minimization of the impact of component tolerances on the performance of the distribution system. The conducted analysis has been confirmed by calculations and measurement results. The presented distribution system was designed to provide 100 mW power supply to each of the ten possible receivers in a limited 490 x 350 mm cage space while using a single transmitter working at the coupling resonant frequency of 27 MHz.

  2. Models in palaeontological functional analysis

    PubMed Central

    Anderson, Philip S. L.; Bright, Jen A.; Gill, Pamela G.; Palmer, Colin; Rayfield, Emily J.

    2012-01-01

    Models are a principal tool of modern science. By definition, and in practice, models are not literal representations of reality but provide simplifications or substitutes of the events, scenarios or behaviours that are being studied or predicted. All models make assumptions, and palaeontological models in particular require additional assumptions to study unobservable events in deep time. In the case of functional analysis, the degree of missing data associated with reconstructing musculoskeletal anatomy and neuronal control in extinct organisms has, in the eyes of some scientists, rendered detailed functional analysis of fossils intractable. Such a prognosis may indeed be realized if palaeontologists attempt to recreate elaborate biomechanical models based on missing data and loosely justified assumptions. Yet multiple enabling methodologies and techniques now exist: tools for bracketing boundaries of reality; more rigorous consideration of soft tissues and missing data and methods drawing on physical principles that all organisms must adhere to. As with many aspects of science, the utility of such biomechanical models depends on the questions they seek to address, and the accuracy and validity of the models themselves. PMID:21865242

  3. Introduction to the thermodynamic Bethe ansatz

    NASA Astrophysics Data System (ADS)

    van Tongeren, Stijn J.

    2016-08-01

    We give a pedagogical introduction to the thermodynamic Bethe ansatz, a method that allows us to describe the thermodynamics of integrable models whose spectrum is found via the (asymptotic) Bethe ansatz. We set the stage by deriving the Fermi-Dirac distribution and associated free energy of free electrons, and then in a similar though technically more complicated fashion treat the thermodynamics of integrable models, focusing first on the one-dimensional Bose gas with delta function interaction as a clean pedagogical example, secondly the XXX spin chain as an elementary (lattice) model with prototypical complicating features in the form of bound states, and finally the {SU}(2) chiral Gross-Neveu model as a field theory example. Throughout this discussion we emphasize the central role of particle and hole densities, whose relations determine the model under consideration. We then discuss tricks that allow us to use the same methods to describe the exact spectra of integrable field theories on a circle, in particular the chiral Gross-Neveu model. We moreover discuss the simplification of TBA equations to Y systems, including the transition back to integral equations given sufficient analyticity data, in simple examples.

  4. Novel Soft-Pion Theorem for Long-Range Nuclear Parity Violation

    NASA Astrophysics Data System (ADS)

    Feng, Xu; Guo, Feng-Kun; Seng, Chien-Yeah

    2018-05-01

    The parity-odd effect in the standard model weak neutral current reveals itself in the long-range parity-violating nuclear potential generated by the pion exchanges in the Δ I =1 channel with the parity-odd pion-nucleon coupling constant hπ1 . Despite decades of experimental and theoretical efforts, the size of this coupling constant is still not well understood. In this Letter, we derive a soft-pion theorem relating hπ1 and the neutron-proton mass splitting induced by an artificial parity-even counterpart of the Δ I =1 weak Lagrangian and demonstrate that the theorem still holds exact at the next-to-leading order in the chiral perturbation theory. A considerable amount of simplification is expected in the study of hπ1 by using either lattice or other QCD models following its reduction from a parity-odd proton-neutron-pion matrix element to a simpler spectroscopic quantity. The theorem paves the way to much more precise calculations of hπ1, and thus a quantitative test of the strangeness-conserving neutral current interaction of the standard model is foreseen.

  5. Fisheye camera method for spatial non-uniformity corrections in luminous flux measurements with integrating spheres

    NASA Astrophysics Data System (ADS)

    Kokka, Alexander; Pulli, Tomi; Poikonen, Tuomas; Askola, Janne; Ikonen, Erkki

    2017-08-01

    This paper presents a fisheye camera method for determining spatial non-uniformity corrections in luminous flux measurements with integrating spheres. Using a fisheye camera installed into a port of an integrating sphere, the relative angular intensity distribution of the lamp under test is determined. This angular distribution is used for calculating the spatial non-uniformity correction for the lamp when combined with the spatial responsivity data of the sphere. The method was validated by comparing it to a traditional goniophotometric approach when determining spatial correction factors for 13 LED lamps with different angular spreads. The deviations between the spatial correction factors obtained using the two methods ranged from -0.15 % to 0.15%. The mean magnitude of the deviations was 0.06%. For a typical LED lamp, the expanded uncertainty (k = 2 ) for the spatial non-uniformity correction factor was evaluated to be 0.28%. The fisheye camera method removes the need for goniophotometric measurements in determining spatial non-uniformity corrections, thus resulting in considerable system simplification. Generally, no permanent modifications to existing integrating spheres are required.

  6. Controlled Ecological Life Support System: Use of Higher Plants

    NASA Technical Reports Server (NTRS)

    Tibbits, T. W.; Alford, D. K.

    1982-01-01

    Results of two workshops concerning the use of higher plants in Controlled Ecological Life Support Systems (CELSS) are summarized. Criteria for plant selection were identified from these categories: food production, nutrition, oxygen production and carbon dioxide utilization, water recycling, waste recycling, and other morphological and physiological considerations. Types of plant species suitable for use in CELSS, growing procedures, and research priorities were recommended. Also included are productivity values for selected plant species.

  7. Diet simplification selects for high gut microbial diversity and strong fermenting ability in high-altitude pikas.

    PubMed

    Li, Huan; Qu, Jiapeng; Li, Tongtong; Wirth, Stephan; Zhang, Yanming; Zhao, Xinquan; Li, Xiangzhen

    2018-06-03

    The gut microbiota in mammals plays a key role in host metabolism and adaptation. However, relatively little is known regarding to how the animals adapts to extreme environments through regulating gut microbial diversity and function. Here, we investigated the diet, gut microbiota, short-chain fatty acid (SCFA) profiles, and cellulolytic activity from two common pika (Ochotona spp.) species in China, including Plateau pika (Ochotona curzoniae) from the Qinghai-Tibet Plateau and Daurian pika (Ochotona daurica) from the Inner Mongolia Grassland. Despite a partial diet overlap, Plateau pikas harbored lower diet diversity than Daurian pikas. Some bacteria (e.g., Prevotella and Ruminococcus) associated with fiber degradation were enriched in Plateau pikas. They harbored higher gut microbial diversity, total SCFA concentration, and cellulolytic activity than Daurian pikas. Interestingly, cellulolytic activity was positively correlated with the gut microbial diversity and SCFAs. Gut microbial communities and SCFA profiles were segregated structurally between host species. PICRUSt metagenome predictions demonstrated that microbial genes involved in carbohydrate metabolism and energy metabolism were overrepresented in the gut microbiota of Plateau pikas. Our results demonstrate that Plateau pikas harbor a stronger fermenting ability for the plant-based diet than Daurian pikas via gut microbial fermentation. The enhanced ability for utilization of plant-based diets in Plateau pikas may be partly a kind of microbiota adaptation for more energy requirements in cold and hypoxic high-altitude environments.

  8. ASTRID© - Advanced Solar Tubular ReceIver Design: A powerful tool for receiver design and optimization

    NASA Astrophysics Data System (ADS)

    Frantz, Cathy; Fritsch, Andreas; Uhlig, Ralf

    2017-06-01

    In solar tower power plants the receiver is one of the critical components. It converts the solar radiation into heat and must withstand high heat flux densities and high daily or even hourly gradients (due to passage of clouds). For this reason, the challenge during receiver design is to find a reasonable compromise between receiver efficiency, reliability, lifetime and cost. There is a strong interaction between the heliostat field, the receiver and the heat transfer fluid. Therefore, a proper receiver design needs to consider these components within the receiver optimization. There are several design and optimization tools for receivers, but most of them focus only on the receiver, ignoring the heliostat field and other parts of the plant. During the last years DLR developed the ASTRIDcode for tubular receiver concept simulation. The code comprises both a high and a low-detail model. The low-detail model utilizes a number of simplifications which allow the user to screen a high number of receiver concepts for optimization purposes. The high-detail model uses a FE model and is able to compute local absorber and salt temperatures with high accuracy. One key strength of the ASTRIDcode is its interface to a ray tracing software which simulates a realistic heat flux distributions on the receiver surface. The results generated by the ASTRIDcode have been validated by CFD simulations and measurement data.

  9. A thermodynamic approach to model the caloric properties of semicrystalline polymers

    NASA Astrophysics Data System (ADS)

    Lion, Alexander; Johlitz, Michael

    2016-05-01

    It is well known that the crystallisation and melting behaviour of semicrystalline polymers depends in a pronounced manner on the temperature history. If the polymer is in the liquid state above the melting point, and the temperature is reduced to a level below the glass transition, the final degree of crystallinity, the amount of the rigid amorphous phase and the configurational state of the mobile amorphous phase strongly depend on the cooling rate. If the temperature is increased afterwards, the extents of cold crystallisation and melting are functions of the heating rate. Since crystalline and amorphous phases exhibit different densities, the specific volume depends also on the temperature history. In this article, a thermodynamically based phenomenological approach is developed which allows for the constitutive representation of these phenomena in the time domain. The degree of crystallinity and the configuration of the amorphous phase are represented by two internal state variables whose evolution equations are formulated under consideration of the second law of thermodynamics. The model for the specific Gibbs free energy takes the chemical potentials of the different phases and the mixture entropy into account. For simplification, it is assumed that the amount of the rigid amorphous phase is proportional to the degree of crystallinity. An essential outcome of the model is an equation in closed form for the equilibrium degree of crystallinity in dependence on pressure and temperature. Numerical simulations demonstrate that the process dependences of crystallisation and melting under consideration of the glass transition are represented.

  10. A database for medicinal plants used in treatment of asthma

    PubMed Central

    Kasirajan, Balaji; Maruthamuthu, Rajadurai; Gopalakrishnan, Vidhya; Arumugam, Krithika; Asirvatham, Hudson; Murali, Vidya; Mohandass, Ramya; Bhaskar, Anusha

    2007-01-01

    The knowledge of most plants used in the treatment of asthma, the plant part which is effective in treatment is confined to very few persons who are engaged in folklore medicine. However, this form of medicine is not very popular. Therefore, it is of considerable interest to ethno-botanical community to understand the plants and the parts used for treatment. Here, we describe AsthmaPlantBase, a database containing information of medicinal plants for treatment of asthma. Availability http://www.asthmaplants.com. PMID:18288333

  11. Modeling fructose-load-induced hepatic de-novo lipogenesis by model simplification.

    PubMed

    Allen, Richard J; Musante, Cynthia J

    2017-01-01

    Hepatic de-novo lipogenesis is a metabolic process implemented in the pathogenesis of type 2 diabetes. Clinically, the rate of this process can be ascertained by use of labeled acetate and stimulation by fructose administration. A systems pharmacology model of this process is desirable because it facilitates the description, analysis, and prediction of this experiment. Due to the multiple enzymes involved in de-novo lipogenesis, and the limited data, it is desirable to use single functional expressions to encapsulate the flux between multiple enzymes. To accomplish this we developed a novel simplification technique which uses the available information about the properties of the individual enzymes to bound the parameters of a single governing 'transfer function'. This method should be applicable to any model with linear chains of enzymes that are well stimulated. We validated this approach with computational simulations and analytical justification in a limiting case. Using this technique we generated a simple model of hepatic de-novo lipogenesis in these experimental conditions that matched prior data. This model can be used to assess pharmacological intervention at specific points on this pathway. We have demonstrated this with prospective simulation of acetyl-CoA carboxylase inhibition. This simplification technique suggests how the constituent properties of an enzymatic chain of reactions gives rise to the sensitivity (to substrate) of the pathway as a whole.

  12. Modeling fructose-load-induced hepatic de-novo lipogenesis by model simplification

    PubMed Central

    Allen, Richard J; Musante, Cynthia J

    2017-01-01

    Hepatic de-novo lipogenesis is a metabolic process implemented in the pathogenesis of type 2 diabetes. Clinically, the rate of this process can be ascertained by use of labeled acetate and stimulation by fructose administration. A systems pharmacology model of this process is desirable because it facilitates the description, analysis, and prediction of this experiment. Due to the multiple enzymes involved in de-novo lipogenesis, and the limited data, it is desirable to use single functional expressions to encapsulate the flux between multiple enzymes. To accomplish this we developed a novel simplification technique which uses the available information about the properties of the individual enzymes to bound the parameters of a single governing ‘transfer function’. This method should be applicable to any model with linear chains of enzymes that are well stimulated. We validated this approach with computational simulations and analytical justification in a limiting case. Using this technique we generated a simple model of hepatic de-novo lipogenesis in these experimental conditions that matched prior data. This model can be used to assess pharmacological intervention at specific points on this pathway. We have demonstrated this with prospective simulation of acetyl-CoA carboxylase inhibition. This simplification technique suggests how the constituent properties of an enzymatic chain of reactions gives rise to the sensitivity (to substrate) of the pathway as a whole. PMID:28469410

  13. How students process equations in solving quantitative synthesis problems? Role of mathematical complexity in students' mathematical performance

    NASA Astrophysics Data System (ADS)

    Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

    2017-12-01

    We examine students' mathematical performance on quantitative "synthesis problems" with varying mathematical complexity. Synthesis problems are tasks comprising multiple concepts typically taught in different chapters. Mathematical performance refers to the formulation, combination, and simplification of equations. Generally speaking, formulation and combination of equations require conceptual reasoning; simplification of equations requires manipulation of equations as computational tools. Mathematical complexity is operationally defined by the number and the type of equations to be manipulated concurrently due to the number of unknowns in each equation. We use two types of synthesis problems, namely, sequential and simultaneous tasks. Sequential synthesis tasks require a chronological application of pertinent concepts, and simultaneous synthesis tasks require a concurrent application of the pertinent concepts. A total of 179 physics major students from a second year mechanics course participated in the study. Data were collected from written tasks and individual interviews. Results show that mathematical complexity negatively influences the students' mathematical performance on both types of synthesis problems. However, for the sequential synthesis tasks, it interferes only with the students' simplification of equations. For the simultaneous synthesis tasks, mathematical complexity additionally impedes the students' formulation and combination of equations. Several reasons may explain this difference, including the students' different approaches to the two types of synthesis problems, cognitive load, and the variation of mathematical complexity within each synthesis type.

  14. Administrative simplification, simplified for Hawai'i.

    PubMed

    Sakamoto, David

    2012-04-01

    The American health care system contains a layer of administrative controls that has become increasingly burdensome to medical practices in terms of uncompensated physician and staff time and practice costs. A primary care physician in solo practice spends between 4 and 10 hours a week directly interacting with health insurance companies and his or her staff will spend an additional 60 hours a week. This reduces patient-care availability, net practice income and physician job satisfaction. A literature review was conducted to determine possible solutions to administrative burdens physicians face in Hawai'i. A total of 51 articles were found matching search criteria with five being reports from major organizations. Twenty-seven articles were found that related to administrative simplification. The "administrative complexity" problem has been defined and its financial impact quantified. Promising solutions have been developed and proposed by private not-for-profit organizations and by the government, both state and federal. A successful administrative simplification plan would: (1) Provide rapid access to insurance information; (2) Allow medical practices to readily track specific claims; (3) Streamline the preauthorization process through the use of decision-support tools at the practice level and by directing interactions through real-time network connections between insurers and provider electronic health records, thus minimizing phone time; (4) Adopt the Universal Provider Datasource system for provider credentialing; and (5) Standardize (to the greatest degree possible) provider/insurer contracts. These solutions are outlined in detail.

  15. Kettlewell's Missing Evidence.

    ERIC Educational Resources Information Center

    Allchin, Douglas Kellogg

    2002-01-01

    The standard textbook account of Kettlewell and the peppered moths omits significant information. Suggests that this case can be used to reflect on the role of simplification in science teaching. (Author/MM)

  16. Pesticide Registration Manual: Chapter 3 - Additional Considerations for Biopesticide Products

    EPA Pesticide Factsheets

    Biopesticides are certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals that fall into three major classes: microbial pesticides, plant-incorporated protectants, and biochemical pesticides.

  17. Subalpine vegetation pattern three decades after stand-replacing fire: Effects of landscape context and topography on plant community composition, tree regeneration, and diversity

    Treesearch

    Jonathan D. Coop; Robert T. Massatti; Anna W. Schoettle

    2010-01-01

    These subalpine wildfires generated considerable, persistent increases in plant species richness at local and landscape scales, and a diversity of plant communities. The findings suggest that fire suppression in such systems must lead to reduced diversity. Concerns about post-fire invasion by exotic plants appear unwarranted in high-elevation wilderness settings.

  18. Tree planting experiences in the eastern interior coal province

    Treesearch

    Charles Medvick

    1980-01-01

    Fruit trees were planted successfully in 1918 and organized afforestation began in 1928. Professional foresters had a hand in some of the very earliest planting projects. Formal reclamation research played an important role in applying science to early reclamation technology; however, considerable work has preceded the scientists. Some success has been experienced with...

  19. 78 FR 4137 - Notice for the Great Lakes and Mississippi River Interbasin Study (GLMRIS)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-18

    ... that can be used to prevent the transfer of algae, crustaceans, fish and plants via aquatic pathways... be effective at preventing the transfer of fish, algae, crustaceans and plants in the CAWS but are... warranting further consideration to the following: algae, crustaceans, fish and plants. Additionally, USACE...

  20. Forestation of surface mines for wildlife

    Treesearch

    Thomas G. Zarger

    1980-01-01

    This report reviews TVA program efforts to promote the use of wildlife shrubs in mined-land reclamation including work on plant materials development, demonstrations to acquaint landowners with a variety of food and cover plants, and action programs to incorporate wildlife plants into postmining land use. It deals briefly with wildlife considerations under Public Law...

  1. The plant vascular system: Evolution, development and functions

    Treesearch

    William J. Lucas; Andrew Groover; Raffael Lichtenberger; Kaori Furuta; Shri-Ram Yadav; Yka Helariutta; Xin-Qiang He; Hiroo Fukuda; Julie Kang; Siobhan M. Brady; John W. Patrick; John Sperry; Akiko Yoshida; Ana-Flor Lopez-Millan; Michael A. Grusak; Pradeep Kachroo

    2013-01-01

    The emergence of the tracheophyte-based vascular system of land plants had major impacts on the evolution of terrestrial biology, in general, through its role in facilitating the development of plants with increased stature, photosynthetic output, and ability to colonize a greatly expanded range of environmental habitats. Recently, considerable progress has been made...

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

    Bradt, M.; Behnke, M. R.; Bloethe, W.G.

    This paper presents a summary of the most important protection and coordination considerations for wind power plants. Short-circuit characteristics of both aggregate wind plant and individual wind turbine genera- tors, as well as general interconnection protection requirements are discussed. Many factors such as security, reliability, and safety are considered for proper conservative protection of the wind power plant and individual turbines.

  3. On the role of plant mitochondrial metabolism and its impact on photosynthesis in both optimal and sub-optimal growth conditions.

    PubMed

    Araújo, Wagner L; Nunes-Nesi, Adriano; Fernie, Alisdair R

    2014-02-01

    Given that the pathways of photosynthesis and respiration catalyze partially opposing processes, it follows that their relative activities must be carefully regulated within plant cells. Recent evidence has shown that the components of the mitochondrial electron transport chain are essential for the proper maintenance of intracellular redox gradients, to allow considerable rates of photorespiration and in turn efficient photosynthesis. Thus considerable advances have been made in understanding the interaction between respiration and photosynthesis during the last decades and the potential mechanisms linking mitochondrial function and photosynthetic efficiency will be reviewed. Despite the fact that manipulation of various steps of mitochondrial metabolism has been demonstrated to alter photosynthesis under optimal growth conditions, it is likely that these changes will, by and large, not be maintained under sub-optimal situations. Therefore producing plants to meet this aim remains a critical challenge. It is clear, however, that although there have been a range of studies analysing changes in respiratory and photosynthetic rates in response to light, temperature and CO2, our knowledge of the environmental impact on these processes and its linkage still remains fragmented. We will also discuss the metabolic changes associated to plant respiration and photosynthesis as important components of the survival strategy as they considerably extend the period that a plant can withstand to a stress situation.

  4. Sound Recording Simplification Act

    THOMAS, 112th Congress

    Rep. Polis, Jared [D-CO-2

    2011-09-14

    House - 09/23/2011 Referred to the Subcommittee on Intellectual Property, Competition and the Internet. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  5. Adapting the Euler-Lagrange equation to study one-dimensional motions under the action of a constant force

    NASA Astrophysics Data System (ADS)

    Dias, Clenilda F.; Araújo, Maria A. S.; Carvalho-Santos, Vagson L.

    2018-01-01

    The Euler-Lagrange equations (ELE) are very important in the theoretical description of several physical systems. In this work we have used a simplified form of ELE to study one-dimensional motions under the action of a constant force. From the use of the definition of partial derivative, we have proposed two operators, here called mean delta operators, which may be used to solve the ELE in a simplest way. We have applied this simplification to solve three simple mechanical problems in which the particle is under the action of the gravitational field: a free fall body, the Atwood’s machine and the inclined plan. The proposed simplification can be used to introduce the lagrangian formalism in teaching classical mechanics in introductory physics courses.

  6. Flexible aircraft dynamic modeling for dynamic analysis and control synthesis

    NASA Technical Reports Server (NTRS)

    Schmidt, David K.

    1989-01-01

    The linearization and simplification of a nonlinear, literal model for flexible aircraft is highlighted. Areas of model fidelity that are critical if the model is to be used for control system synthesis are developed and several simplification techniques that can deliver the necessary model fidelity are discussed. These techniques include both numerical and analytical approaches. An analytical approach, based on first-order sensitivity theory is shown to lead not only to excellent numerical results, but also to closed-form analytical expressions for key system dynamic properties such as the pole/zero factors of the vehicle transfer-function matrix. The analytical results are expressed in terms of vehicle mass properties, vibrational characteristics, and rigid-body and aeroelastic stability derivatives, thus leading to the underlying causes for critical dynamic characteristics.

  7. A guide to the contained use of plant virus infectious clones.

    PubMed

    Brewer, Helen C; Hird, Diane L; Bailey, Andy M; Seal, Susan E; Foster, Gary D

    2018-04-01

    Plant virus infectious clones are important tools with wide-ranging applications in different areas of biology and medicine. Their uses in plant pathology include the study of plant-virus interactions, and screening of germplasm as part of prebreeding programmes for virus resistance. They can also be modified to induce transient plant gene silencing (Virus Induced Gene Silencing - VIGS) and as expression vectors for plant or exogenous proteins, with applications in both plant pathology and more generally for the study of plant gene function. Plant viruses are also increasingly being investigated as expression vectors for in planta production of pharmaceutical products, known as molecular farming. However, plant virus infectious clones may pose a risk to the environment due to their ability to reconstitute fully functional, transmissible viruses. These risks arise from both their inherent pathogenicity and the effect of any introduced genetic modifications. Effective containment measures are therefore required. There has been no single comprehensive review of the biosafety considerations for the contained use of genetically modified plant viruses, despite their increasing importance across many biological fields. This review therefore explores the biosafety considerations for working with genetically modified plant viruses in contained environments, with focus on plant growth facilities. It includes regulatory frameworks, risk assessment, assignment of biosafety levels, facility features and working practices. The review is based on international guidance together with information provided by plant virus researchers. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. Chem Ed Compacts

    ERIC Educational Resources Information Center

    Wolf, Walter A., Ed.

    1977-01-01

    Presents a convenient notation for powers of ten and logarithms, a demonstration of the nonstoichiometry of nickel oxide, a simplification for obtaining Russell-Saunders term symbols, and a scheme for biochemistry laboratory experiments. (SL)

  9. Enhancement of efficiency in the use of light for cultivation of plants in controlled ecological systems

    NASA Technical Reports Server (NTRS)

    Mashinsky, A. L.; Oreshkin, V. I.; Nechitailo, G. S.

    1994-01-01

    The problems of plant cultivation with the use of artificial lighting are related to energetics and, initially, to the lack of effective sources for photosynthesis, secondly to the necessity to supply a system with a considerable power in the form of light energy and to remove transformed thermal energy, and finally to economic considerations. These problems are solved by three ways: by the choice of effective radiation sources, design approaches, and technological methods of cultivation. Here we shall consider the first two ways.

  10. Developing an Interactive Augmented Reality System as a Complement to Plant Education and Comparing Its Effectiveness with Video Learning

    ERIC Educational Resources Information Center

    Chang, Rong-Chi; Chung, Liang-Yi; Huang, Yong-Ming

    2016-01-01

    The learning of plants has garnered considerable attention in recent years, but students often lack the motivation to learn about the process of plant growth. Also, students are not able to apply what they have learned in class in the form of observation, since plant growth takes a long time. In this study, we use augmented reality (AR) technology…

  11. Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities

    PubMed Central

    Griffin, Sharoon; Tittikpina, Nassifatou Koko; Al-marby, Adel; Alkhayer, Reem; Denezhkin, Polina; Witek, Karolina; Gbogbo, Koffi Apeti; Batawila, Komlan; Duval, Raphaël Emmanuel; Nasim, Muhammad Jawad; Awadh-Ali, Nasser A.; Kirsch, Gilbert; Chaimbault, Patrick; Schäfer, Karl-Herbert; Keck, Cornelia M.; Handzlik, Jadwiga; Jacob, Claus

    2016-01-01

    Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude “waste” plant materials for specific practical applications, especially—but not exclusively—in developing countries lacking a more sophisticated industrial infrastructure. PMID:27104554

  12. Flow Accelerated Erosion-Corrosion (FAC) considerations for secondary side piping in the AP1000{sup R} nuclear power plant design

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

    Vanderhoff, J. F.; Rao, G. V.; Stein, A.

    2012-07-01

    The issue of Flow Accelerated Erosion-Corrosion (FAC) in power plant piping is a known phenomenon that has resulted in material replacements and plant accidents in operating power plants. Therefore, it is important for FAC resistance to be considered in the design of new nuclear power plants. This paper describes the design considerations related to FAC that were used to develop a safe and robust AP1000{sup R} plant secondary side piping design. The primary FAC influencing factors include: - Fluid Temperature - Pipe Geometry/layout - Fluid Chemistry - Fluid Velocity - Pipe Material Composition - Moisture Content (in steam lines) Duemore » to the unknowns related to the relative impact of the influencing factors and the complexities of the interactions between these factors, it is difficult to accurately predict the expected wear rate in a given piping segment in a new plant. This paper provides: - a description of FAC and the factors that influence the FAC degradation rate, - an assessment of the level of FAC resistance of AP1000{sup R} secondary side system piping, - an explanation of options to increase FAC resistance and associated benefits/cost, - discussion of development of a tool for predicting FAC degradation rate in new nuclear power plants. (authors)« less

  13. Highlights of the International Symposium on Plant Lipids, 18th ISPL 2008, Bordeaux July 20–25th, 2008

    USDA-ARS?s Scientific Manuscript database

    Plant lipids are of considerable interest in economic sectors such as agriculture, food, health and the cosmetics industry. In addition, the sector of renewable energies is showing increasing interest in the field of plant lipids. Our society is highly dependent on raw fossil materials whose reserve...

  14. Dehydropyrrolizidine alkaloid toxicity, cytotoxicity, and carcinogenicity

    USDA-ARS?s Scientific Manuscript database

    Dehyro-pyrrolizidine alkaloid (PA)-containing plants compose about 5% of the world’s flowering plants and they commonly poison livestock, wildlife and humans. Previous work has produced considerable understanding of PA toxicity, species susceptibility, conditions and routes of exposure, toxin metab...

  15. A fuel cell balance of plant test facility

    NASA Astrophysics Data System (ADS)

    Dicks, A. L.; Martin, P. A.

    Much attention is focused in the fuel cell community on the development of reliable stack technology, but to successfully exploit fuel cells, they must form part of integrated power generation systems. No universal test facilities exist to evaluate SOFC stacks and comparatively little research has been undertaken concerning the issues of the rest of the system, or balance of plant (BOP). BG, in collaboration with Eniricerche, has therefore recently designed and built a test facility to evaluate different configurations of the BOP equipment for a 1-5 kWe solid oxide fuel cell (SOFC) stack. Within this BOP project, integrated, dynamic models have been developed. These have shown that three characteristic response times exist when the stack load is changed and that three independent control loops are required to manage the almost instantaneous change in power output from an SOFC stack, maintain the fuel utilisation and control the stack temperature. Control strategies and plant simplifications, arising from the dynamic modelling, have also been implemented in the BOP test facility. An SOFC simulator was designed and integrated into the control system of the test rig to behave as a real SOFC stack, allowing the development of control strategies without the need for a real stack. A novel combustor has been specifically designed, built and demonstrated to be capable of burning the low calorific anode exhaust gas from an SOFC using the oxygen depleted cathode stream. High temperature, low cost, shell and tube heat exchangers have been shown to be suitable for SOFC systems. Sealing of high temperature anode recirculation fans has, however, been shown to be a major issue and identified as a key area for further investigation.

  16. EPRI/DOE High Burnup Fuel Sister Pin Test Plan Simplification and Visualization

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

    Saltzstein, Sylvia J.; Sorenson, Ken B.; Hanson, Brady

    The EPRI/DOE High Burnup Confirmatory Data Project (herein called the "Demo") is a multi-year, multi-entity confirmation demonstration test with the purpose of providing quantitative and qualitative data to show how high-burnup fuel ages in dry storage over a ten-year period. The Demo involves obtaining 32 assemblies of high-burnup PWR fuel of four common cladding alloys from the North Anna Nuclear Power Plant, drying them according to standard plant procedures, and then storing them in an NRC-licensed TN-3 2B cask on the North Anna dry storage pad for ten years. After the ten-year storage time, the cask will be opened andmore » the rods will be examined for signs of aging. Twenty-five rods from assemblies of similar claddings, in-reactor placement, and burnup histories (herein called "sister rods") have been shipped from the North Anna Nuclear Power Plant and are currently being nondestructively tested at Oak Ridge National Laboratory. After the non-destructive testing has been completed for each of the twenty-five rods, destructive analysis will be performed at ORNL, PNNL, and ANL to obtain mechanical data. Opinions gathered from the expert interviews, ORNL and PNNL Sister Rod Test Plans, and numerous meetings has resulted in the Simplified Test Plan described in this document. Some of the opinions and discussions leading to the simplified test plan are included here. Detailed descriptions and background are in the ORNL and PNNL plans in the appendices . After the testing described in this simplified test plan h as been completed , the community will review all the collected data and determine if additional testing is needed.« less

  17. Feasibility Study of Supercritical Light Water Cooled Reactors for Electric Power Production, Nuclear Energy Research Initiative Project 2001-001, Westinghouse Electric Co. Grant Number: DE-FG07-02SF22533, Final Report

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

    Philip E. MacDonald

    2005-01-01

    The supercritical water-cooled reactor (SCWR) is one of the six reactor technologies selected for research and development under the Generation IV program. SCWRs are promising advanced nuclear systems because of their high thermal efficiency (i.e., about 45% versus about 33% efficiency for current Light Water Reactors [LWRs]) and considerable plant simplification. SCWRs are basically LWRs operating at higher pressure and temperatures with a direct once-through cycle. Operation above the critical pressure eliminates coolant boiling, so the coolant remains single-phase throughout the system. Thus, the need for a pressurizer, steam generators, steam separators, and dryers is eliminated. The main mission ofmore » the SCWR is generation of low-cost electricity. It is built upon two proven technologies: LWRs, which are the most commonly deployed power generating reactors in the world, and supercritical fossil-fired boilers, a large number of which are also in use around the world. The reference SCWR design for the U.S. program is a direct cycle system operating at 25.0 MPa, with core inlet and outlet temperatures of 280 and 500 C, respectively. The coolant density decreases from about 760 kg/m3 at the core inlet to about 90 kg/m3 at the core outlet. The inlet flow splits with about 10% of the inlet flow going down the space between the core barrel and the reactor pressure vessel (the downcomer) and about 90% of the inlet flow going to the plenum at the top of the rector pressure vessel, to then flow down through the core in special water rods to the inlet plenum. Here it mixes with the feedwater from the downcomer and flows upward to remove the heat in the fuel channels. This strategy is employed to provide good moderation at the top of the core. The coolant is heated to about 500 C and delivered to the turbine. The purpose of this NERI project was to assess the reference U.S. Generation IV SCWR design and explore alternatives to determine feasibility. The project was organized into three tasks: Task 1. Fuel-cycle Neutronic Analysis and Reactor Core Design Task 2. Fuel Cladding and Structural Material Corrosion and Stress Corrosion Cracking Task 3. Plant Engineering and Reactor Safety Analysis. moderator rods. materials.« less

  18. Affordable Housing Regulation Simplification Act of 2012

    THOMAS, 112th Congress

    Rep. Polis, Jared [D-CO-2

    2012-09-13

    House - 10/01/2012 Referred to the Subcommittee on Capital Markets and Government Sponsored Enterprises. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  19. Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional-structural plant model.

    PubMed

    Sarlikioti, V; de Visser, P H B; Marcelis, L F M

    2011-04-01

    At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional-structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north-south orientation of rows differed from east-west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the experimental approach of photosynthesis measurements for model parameterization should be revised.

  20. Exploring the spatial distribution of light interception and photosynthesis of canopies by means of a functional–structural plant model

    PubMed Central

    Sarlikioti, V.; de Visser, P. H. B.; Marcelis, L. F. M.

    2011-01-01

    Background and Aims At present most process-based models and the majority of three-dimensional models include simplifications of plant architecture that can compromise the accuracy of light interception simulations and, accordingly, canopy photosynthesis. The aim of this paper is to analyse canopy heterogeneity of an explicitly described tomato canopy in relation to temporal dynamics of horizontal and vertical light distribution and photosynthesis under direct- and diffuse-light conditions. Methods Detailed measurements of canopy architecture, light interception and leaf photosynthesis were carried out on a tomato crop. These data were used for the development and calibration of a functional–structural tomato model. The model consisted of an architectural static virtual plant coupled with a nested radiosity model for light calculations and a leaf photosynthesis module. Different scenarios of horizontal and vertical distribution of light interception, incident light and photosynthesis were investigated under diffuse and direct light conditions. Key Results Simulated light interception showed a good correspondence to the measured values. Explicitly described leaf angles resulted in higher light interception in the middle of the plant canopy compared with fixed and ellipsoidal leaf-angle distribution models, although the total light interception remained the same. The fraction of light intercepted at a north–south orientation of rows differed from east–west orientation by 10 % on winter and 23 % on summer days. The horizontal distribution of photosynthesis differed significantly between the top, middle and lower canopy layer. Taking into account the vertical variation of leaf photosynthetic parameters in the canopy, led to approx. 8 % increase on simulated canopy photosynthesis. Conclusions Leaf angles of heterogeneous canopies should be explicitly described as they have a big impact both on light distribution and photosynthesis. Especially, the vertical variation of photosynthesis in canopy is such that the experimental approach of photosynthesis measurements for model parameterization should be revised. PMID:21355008

  1. Plant communities as drivers of soil respiration: pathways, mechanisms, and significance for global change

    NASA Astrophysics Data System (ADS)

    Metcalfe, D. B.; Fisher, R. A.; Wardle, D. A.

    2011-08-01

    Understanding the impacts of plant community characteristics on soil carbon dioxide efflux (R) is a key prerequisite for accurate prediction of the future carbon (C) balance of terrestrial ecosystems under climate change. However, developing a mechanistic understanding of the determinants of R is complicated by the presence of multiple different sources of respiratory C within soil - such as soil microbes, plant roots and their mycorrhizal symbionts - each with their distinct dynamics and drivers. In this review, we synthesize relevant information from a wide spectrum of sources to evaluate the current state of knowledge about plant community effects on R, examine how this information is incorporated into global climate models, and highlight priorities for future research. Despite often large variation amongst studies and methods, several general trends emerge. Mechanisms whereby plants affect R may be grouped into effects on belowground C allocation, aboveground litter properties and microclimate. Within vegetation types, the amount of C diverted belowground, and hence R, may be controlled mainly by the rate of photosynthetic C uptake, while amongst vegetation types this should be more dependent upon the specific C allocation strategies of the plant life form. We make the case that plant community composition, rather than diversity, is usually the dominant control on R in natural systems. Individual species impacts on R may be largest where the species accounts for most of the biomass in the ecosystem, has very distinct traits to the rest of the community and/or modulates the occurrence of major natural disturbances. We show that climate vegetation models incorporate a number of pathways whereby plants can affect R, but that simplifications regarding allocation schemes and drivers of litter decomposition may limit model accuracy. We also suggest that under a warmer future climate, many plant communities may shift towards dominance by fast growing plants which produce large quantities of nutrient rich litter. Where this community shift occurs, it could drive an increase in R beyond that expected from direct climate impacts on soil microbial activity alone. We identify key gaps in knowledge and recommend them as priorities for future work. These include the patterns of photosynthate partitioning amongst belowground components, ecosystem level effects of individual plant traits, and the importance of trophic interactions and species invasions or extinctions for ecosystem processes. A final, overarching challenge is how to link these observations and drivers across spatio-temporal scales to predict regional or global changes in R over long time periods. A more unified approach to understanding R, which integrates information about plant traits and community dynamics, will be essential for better understanding, simulating and predicting patterns of R across terrestrial ecosystems and its role within the earth-climate system.

  2. Designing the School Plant as a Community Center.

    ERIC Educational Resources Information Center

    New York State Education Dept., Albany. Div. of School Buildings and Grounds.

    In the planning of school plants to serve the educational, social, civic, recreational, and cultural needs of the entire community, factors which receive special consideration are location of facilities, heat distribution, zoning, storage space, and special appointments and service features. (RH)

  3. 25 CFR 700.313 - Evidence and procedure.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... relevant evidence; (4) Take depositions or have depositions taken when the ends of justice would be served... conferences for the settlement or simplification of the issues; (7) Dispose of procedural requests or similar...

  4. 25 CFR 700.313 - Evidence and procedure.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... relevant evidence; (4) Take depositions or have depositions taken when the ends of justice would be served... conferences for the settlement or simplification of the issues; (7) Dispose of procedural requests or similar...

  5. 25 CFR 700.313 - Evidence and procedure.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... relevant evidence; (4) Take depositions or have depositions taken when the ends of justice would be served... conferences for the settlement or simplification of the issues; (7) Dispose of procedural requests or similar...

  6. 25 CFR 700.313 - Evidence and procedure.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... relevant evidence; (4) Take depositions or have depositions taken when the ends of justice would be served... conferences for the settlement or simplification of the issues; (7) Dispose of procedural requests or similar...

  7. Theory and calculus of cubical complexes

    NASA Technical Reports Server (NTRS)

    Perlman, M.

    1973-01-01

    Combination switching networks with multiple outputs may be represented by Boolean functions. Report has been prepared which describes derivation and use of extraction algorithm that may be adapted to simplification of such simultaneous Boolean functions.

  8. 77 FR 60629 - Administrative Simplification: Adoption of a Standard for a Unique Health Plan Identifier...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... International Organization for Standardization (ISO) Standard, we inadvertently mischaracterized a public... Secretary finds, for good cause, that the notice and comment process is impracticable, unnecessary, or...

  9. Criminal Code Modernization and Simplification Act of 2013

    THOMAS, 113th Congress

    Rep. Sensenbrenner, F. James, Jr. [R-WI-5

    2013-05-07

    House - 06/20/2013 Referred to the Subcommittee on Crime, Terrorism, Homeland Security, and Investigations. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  10. At Home with MS: Adapting Your Environment

    MedlinePlus

    ... improvement. You need not become an efficiency or design expert to develop an interest in making life ... general household hints, getting organized, work simplification, interior design, home remodeling, and home repair. The resources can ...

  11. Simplifications in modelling of dynamical response of coupled electro-mechanical system

    NASA Astrophysics Data System (ADS)

    Darula, Radoslav; Sorokin, Sergey

    2016-12-01

    The choice of a most suitable model of an electro-mechanical system depends on many variables, such as a scale of the system, type and frequency range of its operation, or power requirements. The article focuses on the model of the electromagnetic element used in passive regime (no feedback loops are assumed) and a general lumped parameter model (a conventional mass-spring-damper system coupled to an electric circuit consisting of a resistance, an inductance and a capacitance) is compared with its simplified version, where the full RLC circuit is replaced with its RL simplification, i.e. the capacitance of the electric system is neglected and just its inductance and the resistance are considered. From the comparison of dynamical responses of these systems, the range of applicability of a simplified model is assessed for free as well as forced vibration.

  12. High‐Volume Processed, ITO‐Free Superstrates and Substrates for Roll‐to‐Roll Development of Organic Electronics

    PubMed Central

    Hösel, Markus; Angmo, Dechan; Søndergaard, Roar R.; dos Reis Benatto, Gisele A.; Carlé, Jon E.; Jørgensen, Mikkel

    2014-01-01

    The fabrication of substrates and superstrates prepared by scalable roll‐to‐roll methods is reviewed. The substrates and superstrates that act as the flexible carrier for the processing of functional organic electronic devices are an essential component, and proposals are made about how the general availability of various forms of these materials is needed to accelerate the development of the field of organic electronics. The initial development of the replacement of indium‐tin‐oxide (ITO) for the flexible carrier materials is described and a description of how roll‐to‐roll processing development led to simplification from an initially complex make‐up to higher performing materials through a more simple process is also presented. This process intensification through process simplification is viewed as a central strategy for upscaling, increasing throughput, performance, and cost reduction. PMID:27980893

  13. A robust cloud registration method based on redundant data reduction using backpropagation neural network and shift window

    NASA Astrophysics Data System (ADS)

    Xin, Meiting; Li, Bing; Yan, Xiao; Chen, Lei; Wei, Xiang

    2018-02-01

    A robust coarse-to-fine registration method based on the backpropagation (BP) neural network and shift window technology is proposed in this study. Specifically, there are three steps: coarse alignment between the model data and measured data, data simplification based on the BP neural network and point reservation in the contour region of point clouds, and fine registration with the reweighted iterative closest point algorithm. In the process of rough alignment, the initial rotation matrix and the translation vector between the two datasets are obtained. After performing subsequent simplification operations, the number of points can be reduced greatly. Therefore, the time and space complexity of the accurate registration can be significantly reduced. The experimental results show that the proposed method improves the computational efficiency without loss of accuracy.

  14. An Investigation of Unified Memory Access Performance in CUDA

    PubMed Central

    Landaverde, Raphael; Zhang, Tiansheng; Coskun, Ayse K.; Herbordt, Martin

    2015-01-01

    Managing memory between the CPU and GPU is a major challenge in GPU computing. A programming model, Unified Memory Access (UMA), has been recently introduced by Nvidia to simplify the complexities of memory management while claiming good overall performance. In this paper, we investigate this programming model and evaluate its performance and programming model simplifications based on our experimental results. We find that beyond on-demand data transfers to the CPU, the GPU is also able to request subsets of data it requires on demand. This feature allows UMA to outperform full data transfer methods for certain parallel applications and small data sizes. We also find, however, that for the majority of applications and memory access patterns, the performance overheads associated with UMA are significant, while the simplifications to the programming model restrict flexibility for adding future optimizations. PMID:26594668

  15. Administrative Simplification, Simplified for Hawai‘i

    PubMed Central

    2012-01-01

    Background The American health care system contains a layer of administrative controls that has become increasingly burdensome to medical practices in terms of uncompensated physician and staff time and practice costs. A primary care physician in solo practice spends between 4 and 10 hours a week directly interacting with health insurance companies and his or her staff will spend an additional 60 hours a week. This reduces patient-care availability, net practice income and physician job satisfaction. Methods A literature review was conducted to determine possible solutions to administrative burdens physicians face in Hawai‘i. A total of 51 articles were found matching search criteria with five being reports from major organizations. Results Twenty-seven articles were found that related to administrative simplification. The “administrative complexity” problem has been defined and its financial impact quantified. Promising solutions have been developed and proposed by private not-for-profit organizations and by the government, both state and federal. Discussion A successful administrative simplification plan would: (1) Provide rapid access to insurance information; (2) Allow medical practices to readily track specific claims; (3) Streamline the preauthorization process through the use of decision-support tools at the practice level and by directing interactions through real-time network connections between insurers and provider electronic health records, thus minimizing phone time; (4) Adopt the Universal Provider Datasource system for provider credentialing; and (5) Standardize (to the greatest degree possible) provider/insurer contracts. These solutions are outlined in detail. PMID:22737644

  16. President and Physical Plant Administrator Face Common Goal of Providing an Efficient, Effective Educational Environment.

    ERIC Educational Resources Information Center

    Hansen, Arthur G.

    1975-01-01

    Stresses faced by higher education as a result of both student and social criticism are examined and related to the specific role the physical plant department plays in the changing environment. The interface between the physical plant administrator and the chief executive officer is explored, and consideration is given to what each expects of the…

  17. A guide to medicinal plants of Appalachia

    Treesearch

    Arnold Krochmal; Russell S. Walters; Richard M. Doughty

    1969-01-01

    The Medicinal or therapeutic uses of the plants described in this guide are not to be construed in any way as a recommendation by the authors or the U.S. Department of Agriculture. Some of the dried crude drugs, which must be modified considerably before commercial use, can be extremely poisonous when not used properly. Readers are cautioned against using these plant...

  18. Invasive plants in 21st Century landscapes.

    Treesearch

    Valerie Rapp

    2005-01-01

    A plant species is defined as invasive if it is nonnative to the ecosystem under consideration, and if it causes or is likely to cause economic or environmental harm or harm to human health. Nonnative plant invasions are generally considered to have reached the Pacific Northwest in the mid-1800s with the arrival of European-American settlers. Invasive species such as...

  19. The encroachment of exotic herbaceous plants into the Olympic National Forest.

    Treesearch

    Charles W. Heckman

    1999-01-01

    A floral survey in the Olympic National Forest and its surroundings revealed that a considerable number of introduced ruderal plant species have made deep inroads into the stands of native flora. Some of them, which are mainly of European and Asian origin, have been planted deliberately to stabilize the soil along roadsides and after clear cutting and burning. However...

  20. General considerations in testing and evaluating crop varieties for agroforestry systems

    Treesearch

    Lolita N. Ragus

    1993-01-01

    Introduction of new crops in agroforestry is often suggested as a way to improve productivity. This paper provides general guidelines in selecting companion plant combinations and general considerations in evaluating, testing, naming, maintaining genetic purity and distributing crop varieties to farmers.

  1. Rhizosphere Protists Change Metabolite Profiles in Zea mays.

    PubMed

    Kuppardt, Anke; Fester, Thomas; Härtig, Claus; Chatzinotas, Antonis

    2018-01-01

    Plant growth and productivity depend on the interactions of the plant with the associated rhizosphere microbes. Rhizosphere protists play a significant role in this respect: considerable efforts have been made in the past to reveal the impact of protist-bacteria interactions on the remobilization of essential nutrients for plant uptake, or the grazing induced changes on plant-growth promoting bacteria and the root-architecture. However, the metabolic responses of plants to the presence of protists or to protist-bacteria interactions in the rhizosphere have not yet been analyzed. Here we studied in controlled laboratory experiments the impact of bacterivorous protists in the rhizosphere on maize plant growth parameters and the bacterial community composition. Beyond that we investigated the induction of plant biochemical responses by separately analyzing above- and below-ground metabolite profiles of maize plants incubated either with a soil bacterial inoculum or with a mixture of soil bacteria and bacterivorous protists. Significantly distinct leaf and root metabolite profiles were obtained from plants which grew in the presence of protists. These profiles showed decreased levels of a considerable number of metabolites typical for the plant stress reaction, such as polyols, a number of carbohydrates and metabolites connected to phenolic metabolism. We assume that this decrease in plant stress is connected to the grazing induced shifts in rhizosphere bacterial communities as shown by distinct T-RFLP community profiles. Protist grazing had a clear effect on the overall bacterial community composition, richness and evenness in our microcosms. Given the competition of plant resource allocation to either defense or growth, we propose that a reduction in plant stress levels caused directly or indirectly by protists may be an additional reason for corresponding positive effects on plant growth.

  2. Rhizosphere Protists Change Metabolite Profiles in Zea mays

    PubMed Central

    Kuppardt, Anke; Fester, Thomas; Härtig, Claus; Chatzinotas, Antonis

    2018-01-01

    Plant growth and productivity depend on the interactions of the plant with the associated rhizosphere microbes. Rhizosphere protists play a significant role in this respect: considerable efforts have been made in the past to reveal the impact of protist-bacteria interactions on the remobilization of essential nutrients for plant uptake, or the grazing induced changes on plant-growth promoting bacteria and the root-architecture. However, the metabolic responses of plants to the presence of protists or to protist-bacteria interactions in the rhizosphere have not yet been analyzed. Here we studied in controlled laboratory experiments the impact of bacterivorous protists in the rhizosphere on maize plant growth parameters and the bacterial community composition. Beyond that we investigated the induction of plant biochemical responses by separately analyzing above- and below-ground metabolite profiles of maize plants incubated either with a soil bacterial inoculum or with a mixture of soil bacteria and bacterivorous protists. Significantly distinct leaf and root metabolite profiles were obtained from plants which grew in the presence of protists. These profiles showed decreased levels of a considerable number of metabolites typical for the plant stress reaction, such as polyols, a number of carbohydrates and metabolites connected to phenolic metabolism. We assume that this decrease in plant stress is connected to the grazing induced shifts in rhizosphere bacterial communities as shown by distinct T-RFLP community profiles. Protist grazing had a clear effect on the overall bacterial community composition, richness and evenness in our microcosms. Given the competition of plant resource allocation to either defense or growth, we propose that a reduction in plant stress levels caused directly or indirectly by protists may be an additional reason for corresponding positive effects on plant growth. PMID:29780370

  3. Matrix metalloproteinases: structures, evolution, and diversification.

    PubMed

    Massova, I; Kotra, L P; Fridman, R; Mobashery, S

    1998-09-01

    A comprehensive sequence alignment of 64 members of the family of matrix metalloproteinases (MMPs) for the entire sequences, and subsequently the catalytic and the hemopexin-like domains, have been performed. The 64 MMPs were selected from plants, invertebrates, and vertebrates. The analyses disclosed that as many as 23 distinct subfamilies of these proteins are known to exist. Information from the sequence alignments was correlated with structures, both crystallographic as well as computational, of the catalytic domains for the 23 representative members of the MMP family. A survey of the metal binding sites and two loops containing variable sequences of amino acids, which are important for substrate interactions, are discussed. The collective data support the proposal that the assembly of the domains into multidomain enzymes was likely to be an early evolutionary event. This was followed by diversification, perhaps in parallel among the MMPs, in a subsequent evolutionary time scale. Analysis indicates that a retrograde structure simplification may have accounted for the evolution of MMPs with simple domain constituents, such as matrilysin, from the larger and more elaborate enzymes.

  4. Mycorrhizal mediation of plant response to atmospheric change: Air quality concepts and research considerations.

    PubMed

    Shafer, S R; Schoeneberger, M M

    1991-01-01

    The term 'global climate change' encompasses many physical and chemical changes in the atmosphere that have been induced by anthropogenic pollutants. Increases in concentrations of CO2 and CH4 enhance the 'greenhouse effect' of the atmosphere and may contribute to changes in temperature and precipitation patterns at the earth's surface. Nitrogen oxides and SO2 are phytotoxic and also react with other pollutants to produce other phytotoxins in the troposphere such as O3 and acidic substances. However, release of chlorofluorocarbons into the atmosphere may cause depletion of stratospheric O3, increasing the transmittance of ultraviolet-B (UV-B) radiation to the earth's surface. Increased intensities of UV-B could affect plants and enhance photochemical reactions that generate some phytotoxic pollutants. The role of mycorrhizae in plant responses to such stresses has received little attention. Although plans for several research programs have acknowledged the importance of drought tolerance and soil fertility in plant responses to atmospheric stresses, mycorrhizae are rarely targeted to receive specific investigation. Most vascular land plants form mycorrhizae, so the role of mycorrhizae in mediating plant responses to atmospheric change may be an important consideration in predicting effects of atmospheric changes on plants in managed and natural ecosystems.

  5. Nutrient Considerations for Plants Grown Under Space Flight Conditions

    NASA Technical Reports Server (NTRS)

    Levine, Howard G.; Krikorian, Abraham D.

    2006-01-01

    We present here results on the analysis of 100 mL medium samples extracted from sterilized foam (Smithers-Oasis, Kent OH) used to support the growth of both dicotyledonous (Haplopappus gracilis, n=75) and monocotyledonous (Hemerocallis cv Autumn Blaze, n=25) aseptic plants in NASA's Plant Growth Unit (PGU) during the 5-day CHROMEX-01 Space Shuttle flight (March 1989, STS-29). At recovery, the medium remaining within each of the five floral foam blocks (for both the space flight and ground control experiments) was extracted under vacuum, filtered and subjected to elemental analyses. Concentration levels of some elements remained the same, while some decreased and others increased. A unique aspect of this experiment was that all plants were either aseptic tissue culture generated plantlets or sterile seedling clones, and the design of the PGU facilitated the maintenance of asepsis throughout the mission (confirmed by postflight microbial sampling). This permitted the elimination of microbial considerations in the interpretation of the data. The significance of these findings for growing plants in altered gravity environments are discussed.

  6. Aldose reductase inhibitory, anti-cataract and antioxidant potential of selected medicinal plants from the Marathwada region, India.

    PubMed

    Gacche, R N; Dhole, N A

    2011-04-01

    The water, ethanol and chloroform extracts of selected plants such as Adhatoda vasica (L.) (Acanthaceae), Caesalpinia bonduc (L.), Cassia fistula (L.) (Caesalpiniaceae) and Biophytum sensitivum (L.) (Oxalidaceae) were evaluated for rat lens aldose reductase inhibitory (RLAR) potential, anti-cataract and antioxidant activities. All the samples inhibited the aldose reductase considerably and exhibited anti-cataract activity, while C. fistula (IC(50), 0.154 mg mL(-1)) showed significant RLAR inhibitory activity as compared to the other tested samples, and was further found to be more effective in maintaining sugar-induced lens opacity in the rat lens model. The antioxidant potential of plant extracts was determined using DPPH (2,2-diphenyl-1-picryl hydrazine), hydroxyl (OH), nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) scavenging activities, along with determination of reducing power, ferrous ion chelating ability and inhibition of polyphenol oxidase (PPO). The extracts of the tested plant showed significant free radical scavenging activities and inhibited the activity of enzyme PPO, a model oxidising enzyme. The plant samples were found to possess considerable amounts of vitamin C, total polyphenols and flavonoids.

  7. ETHYLMERCURY: FORMATION IN PLANT TISSUES AND RELATION TO METHYLMERCURY FORMATION

    EPA Science Inventory

    Seedlings of the common dwarf garden pea, Pisum sativum, cv. Little Marvel, exposed to elemental mercury vapor formed both methylmercury and ethylmercury in all parts of the plant. Concentrations of both organomercury compounds fluctuated considerably over a 48-hour exposure peri...

  8. Assessment of Composting Feasibility at Army Installations

    DTIC Science & Technology

    2008-09-01

    The end product is a contaminant-free humus that can enhance landscaping and horticultural applications. Composting costs considerably less than...grasses, flowers, and trees by becoming the humus . Original wetland plants can be restored with the use of compost during planting. Compost provides

  9. Modeling as a tool for management of saline soils and irrigation waters

    USDA-ARS?s Scientific Manuscript database

    Optimal management of saline soils and irrigation waters requires consideration of many interrelated factors including, climate, water applications and timing, water flow, plant water uptake, soil chemical reactions, plant response to salinity and solution composition, soil hydraulic properties and ...

  10. Centrifugation and the Manhattan Project

    NASA Astrophysics Data System (ADS)

    Reed, Cameron

    2009-05-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  11. Centrifugation and the Manhattan Project

    NASA Astrophysics Data System (ADS)

    Reed, Cameron

    2009-04-01

    A study of U. S. Army Manhattan Engineer District documents reveals that consideration of centrifugation as a means of uranium enrichment during World War II was considerably more extensive than is commonly appreciated. By the time the centrifuge project was abandoned in early 1944 a full-scale prototype unit had been fabricated and tested at near-production speeds, enrichments of close to theoretically-expected levels had been demonstrated with pilot-plant units, and plans for production plants had been developed. This paper will review the history of this little-known aspect of the Project and examine the circumstances of how it came to be discontinued.

  12. Student and Family Tax Simplification Act

    THOMAS, 113th Congress

    Rep. Black, Diane [R-TN-6

    2013-10-30

    Senate - 07/29/2014 Read the second time. Placed on Senate Legislative Calendar under General Orders. Calendar No. 493. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

  13. Student Loan Simplification and Opportunity Act of 2011

    THOMAS, 112th Congress

    Sen. Brown, Sherrod [D-OH

    2011-05-25

    Senate - 05/25/2011 Read twice and referred to the Committee on Health, Education, Labor, and Pensions. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

  14. Flow around an individual morphologically complex plant: investigating the role of plant aspect in the numerical prediction of complex river flow

    NASA Astrophysics Data System (ADS)

    Boothroyd, R.; Hardy, R. J.; Warburton, J.; Marjoribanks, T.

    2015-12-01

    Aquatic vegetation has a significant influence on the hydraulic functioning of river systems. Plant morphology has previously been shown to alter the mean and turbulent properties of flow, influenced by the spatial distribution of branches and foliage, and these effects can be further investigated through numerical models. We report on a novel method for the measurement and incorporation of complex plant morphologies into a computational fluid dynamics (CFD) model. The morphological complexity of Prunus laurocerasus is captured under foliated and defoliated states through terrestrial laser scanning (TLS). Point clouds are characterised by a voxelised representation and incorporated into a CFD scheme using a mass flux scaling algorithm, allowing the numerical prediction of flows around individual plants. Here we examine the sensitivity of plant aspect, i.e. the positioning of the plant relative to the primary flow direction, by rotating the voxelised plant representation through 15° increments (24 rotations) about the vertical axis. This enables the impact of plant aspect to be quantified upon the velocity and pressure fields, and in particular how this effects species-specific drag forces and drag coefficients. Plant aspect is shown to considerably influence the flow field response, producing spatially heterogeneous downstream velocity fields with both symmetric and asymmetric wake shapes, and point of reattachments that extend up to seven plant lengths downstream. For the same plant, changes in aspect are shown to account for a maximum variation in drag force of 168%, which equates to a 65% difference in the drag coefficient. An explicit consideration of plant aspect is therefore important in studies concerning flow-vegetation interactions, especially when reducing the uncertainty in parameterising the effect of vegetation in numerical models.

  15. ALARA at nuclear power plants

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

    Baum, J.W.

    1990-01-01

    Implementation of the As Low As Reasonably Achievable (ALARA) principle at nuclear power plants presents a continuing challenge for health physicists at utility corporate and plant levels, for plant designers, and for regulatory agencies. The relatively large collective doses at some plants are being addressed though a variety of dose reduction techniques. It is planned that this report will include material on historical aspects, management, valuation of dose reduction, quantitative and qualitative aspects of optimization, design, operational considerations, and training. The status of this work is summarized in this report. 30 refs., 1 fig., 6 tabs.

  16. Steam plant startup and control in system restoration

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

    Mello, F.P. de; Westcott, J.C.

    1994-02-01

    The IEEE Working Group on Power System Restoration developed a panel session for the Summer Power Meeting on July 14, 1992 on Special Considerations in Power System Restoration. One of the contributions to this session is presented in this paper dealing with aspects of steam plant startup and control in scenarios of system restoration. The topics addressed include the complexity of a steam plant, the contrast between normal plant startups and shutdowns and those following major system blackouts including the effects of plant design, automatic controls, bypass valving and operator training.

  17. Considerations for pattern placement error correction toward 5nm node

    NASA Astrophysics Data System (ADS)

    Yaegashi, Hidetami; Oyama, Kenichi; Hara, Arisa; Natori, Sakurako; Yamauchi, Shohei; Yamato, Masatoshi; Koike, Kyohei; Maslow, Mark John; Timoshkov, Vadim; Kiers, Ton; Di Lorenzo, Paolo; Fonseca, Carlos

    2017-03-01

    Multi-patterning has been adopted widely in high volume manufacturing as 193 immersion extension, and it becomes realistic solution of nano-order scaling. In fact, it must be key technology on single directional (1D) layout design [1] for logic devise and it becomes a major option for further scaling technique in SAQP. The requirement for patterning fidelity control is getting savior more and more, stochastic fluctuation as well as LER (Line edge roughness) has to be micro-scopic observation aria. In our previous work, such atomic order controllability was viable in complemented technique with etching and deposition [2]. Overlay issue form major potion in yield management, therefore, entire solution is needed keenly including alignment accuracy on scanner and detectability on overlay measurement instruments. As EPE (Edge placement error) was defined as the gap between design pattern and contouring of actual pattern edge, pattern registration in single process level must be considerable. The complementary patterning to fabricate 1D layout actually mitigates any process restrictions, however, multiple process step, symbolized as LELE with 193-i, is burden to yield management and affordability. Recent progress of EUV technology is remarkable, and it is major potential solution for such complicated technical issues. EUV has robust resolution limit and it must be definitely strong scaling driver for process simplification. On the other hand, its stochastic variation such like shot noise due to light source power must be resolved with any additional complemented technique. In this work, we examined the nano-order CD and profile control on EUV resist pattern and would introduce excellent accomplishments.

  18. Regenerative life support system research

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Sections on modeling, experimental activities during the grant period, and topics under consideration for the future are contained. The sessions contain discussions of: four concurrent modeling approaches that were being integrated near the end of the period (knowledge-based modeling support infrastructure and data base management, object-oriented steady state simulations for three concepts, steady state mass-balance engineering tradeoff studies, and object-oriented time-step, quasidynamic simulations of generic concepts); interdisciplinary research activities, beginning with a discussion of RECON lab development and use, and followed with discussions of waste processing research, algae studies and subsystem modeling, low pressure growth testing of plants, subsystem modeling of plants, control of plant growth using lighting and CO2 supply as variables, search for and development of lunar soil simulants, preliminary design parameters for a lunar base life support system, and research considerations for food processing in space; and appendix materials, including a discussion of the CELSS Conference, detailed analytical equations for mass-balance modeling, plant modeling equations, and parametric data on existing life support systems for use in modeling.

  19. Evaluation of a rapid diagnostic field test kit for identification of Phytophthora ramorum, P. kernoviae and other Phytophthora species at the point of inspection

    Treesearch

    C.R. Lane; E. Hobden; L. Laurenson; V.C. Barton; K.J.D. Hughes; H. Swan; N. Boonham; A.J. Inman

    2008-01-01

    Plant health regulations to prevent the introduction and spread of Phytophthora ramorum and P. kernoviae require rapid, cost effective diagnostic methods for screening large numbers of plant samples at the time of inspection. Current on-site techniques require expensive equipment, considerable expertise and are not suited for plant...

  20. Screening of plants used in the European traditional medicine to treat memory disorders for acetylcholinesterase inhibitory activity and anti amyloidogenic activity.

    PubMed

    Lobbens, Eva S B; Vissing, Karina J; Jorgensen, Lene; van de Weert, Marco; Jäger, Anna K

    2017-03-22

    Plants used in the traditional medicine of Europe to treat memory dysfunction and/or to enhance memory were investigated for activity against the underlying mechanisms of Alzheimer's disease. To investigate 35 ethanolic extracts of plants, selected using an ethnopharmacological approach, for anti-amyloidogenic activity as well as an ability to inhibit the enzymatic activity of acetylcholinesterase. The anti-amyloidogenic activity of the extracts against amyloid beta was investigated by Thioflavin T fibrillation assays and the ability to inhibit the enzymatic activity of acetylcholinesterase was evaluated monitoring the hydrolysis of acetylthiocholine RESULTS: Under the experimental conditions investigated, extracts of two plants, Carum carvi and Olea sylvestris, inhibited amyloid beta fibrillation considerably, eight plant extracts inhibited amyloid beta fibrillation to some extent, 16 plant extracts had no effect on amyloid beta fibrillation and nine extracts accelerated fibrillation of amyloid beta. Furthermore, five plant extracts from Corydalis species inhibited the enzymatic activity of acetylcholinesterase considerably, one plant extract inhibited the enzymatic activity of acetylcholinesterase to some extent and 29 plant extract had no effect on the enzymatic activity of acetylcholinesterase. An optimal extract in this study would possess acetylcholinesterase inhibitory activity as well as anti-amyloidogenic activity in order to address multiple facets of Alzheimer's disease, until the molecular origin of the disease is unraveled. Unfortunately no such extract was found. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  1. Ecological impacts of arable intensification in Europe.

    PubMed

    Stoate, C; Boatman, N D; Borralho, R J; Carvalho, C R; de Snoo, G R; Eden, P

    2001-12-01

    Although arable landscapes have a long history, environmental problems have accelerated in recent decades. The effects of these changes are usually externalized, being greater for society as a whole than for the farms on which they operate, and incentives to correct them are therefore largely lacking. Arable landscapes are valued by society beyond the farming community, but increased mechanization and farm size, simplification of crop rotations, and loss of non-crop features, have led to a reduction in landscape diversity. Low intensity arable systems have evolved a characteristic and diverse fauna and flora, but development of high input, simplified arable systems has been associated with a decline in biodiversity. Arable intensification has resulted in loss of non-crop habitats and simplification of plant and animal communities within crops, with consequent disruption to food chains and declines in many farmland species. Abandonment of arable management has also led to the replacement of such wildlife with more common and widespread species. Soils have deteriorated as a result of erosion, compaction, loss of organic matter and contamination with pesticides, and in some areas, heavy metals. Impacts on water are closely related to those on soils as nutrient and pesticide pollution of water results from surface runoff and subsurface flow, often associated with soil particles, which themselves have economic and ecological impacts. Nitrates and some pesticides also enter groundwater following leaching from arable land. Greatest impacts are associated with simplified, high input arable systems. Intensification of arable farming has been associated with pollution of air by pesticides, NO2 and CO2, while the loss of soil organic matter has reduced the system's capacity for carbon sequestration. International trade contributes to global climate change through long distance transport of arable inputs and products. The EU Rural Development Regulation (1257/99) provides an opportunity to implement measures for alleviating ecological impacts of arable management through a combination of cross-compliance and agri-environment schemes. To alleviate the problems described in this paper, such measures should take account of opportunities for public/private partnerships and should integrate social, cultural, economic and ecological objectives for multifunctional land use.

  2. The Hidden World within Plants: Ecological and Evolutionary Considerations for Defining Functioning of Microbial Endophytes

    PubMed Central

    van Overbeek, Leonard S.; Berg, Gabriele; Pirttilä, Anna Maria; Compant, Stéphane; Campisano, Andrea; Döring, Matthias; Sessitsch, Angela

    2015-01-01

    SUMMARY All plants are inhabited internally by diverse microbial communities comprising bacterial, archaeal, fungal, and protistic taxa. These microorganisms showing endophytic lifestyles play crucial roles in plant development, growth, fitness, and diversification. The increasing awareness of and information on endophytes provide insight into the complexity of the plant microbiome. The nature of plant-endophyte interactions ranges from mutualism to pathogenicity. This depends on a set of abiotic and biotic factors, including the genotypes of plants and microbes, environmental conditions, and the dynamic network of interactions within the plant biome. In this review, we address the concept of endophytism, considering the latest insights into evolution, plant ecosystem functioning, and multipartite interactions. PMID:26136581

  3. 9 CFR 3.100 - Special considerations regarding compliance and/or variance.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Special considerations regarding compliance and/or variance. 3.100 Section 3.100 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling...

  4. 9 CFR 3.100 - Special considerations regarding compliance and/or variance.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Special considerations regarding compliance and/or variance. 3.100 Section 3.100 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling...

  5. 9 CFR 3.100 - Special considerations regarding compliance and/or variance.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Special considerations regarding compliance and/or variance. 3.100 Section 3.100 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling...

  6. 9 CFR 3.100 - Special considerations regarding compliance and/or variance.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Special considerations regarding compliance and/or variance. 3.100 Section 3.100 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling...

  7. 9 CFR 3.100 - Special considerations regarding compliance and/or variance.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Special considerations regarding compliance and/or variance. 3.100 Section 3.100 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling...

  8. 15 CFR 923.3 - General requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...: resource protection, management of coastal development, and simplification of governmental processes. These...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS General § 923.3 General requirements. (a) The...

  9. 15 CFR 923.3 - General requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...: resource protection, management of coastal development, and simplification of governmental processes. These...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS General § 923.3 General requirements. (a) The...

  10. 15 CFR 923.3 - General requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...: resource protection, management of coastal development, and simplification of governmental processes. These...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS General § 923.3 General requirements. (a) The...

  11. 15 CFR 923.3 - General requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...: resource protection, management of coastal development, and simplification of governmental processes. These...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS General § 923.3 General requirements. (a) The...

  12. 15 CFR 923.3 - General requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...: resource protection, management of coastal development, and simplification of governmental processes. These...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS General § 923.3 General requirements. (a) The...

  13. From Rhetoric to Usefulness.

    ERIC Educational Resources Information Center

    Psacharopoulos, George

    1990-01-01

    Replies to commentaries on the relationship of comparative education theory and practice, addressing the beneficiaries of educational planning and policymaking, the planner's role, evaluation criteria for educational planning, choice of discipline, simplification of theory, analytical versus quantitative research, theoretical foundations of…

  14. Small Business Mergers, Acquisitions, Sales, and Brokerage Simplification Act of 2014

    THOMAS, 113th Congress

    Sen. Manchin, Joe, III [D-WV

    2014-01-14

    Senate - 01/14/2014 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

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

    Dasari, Venkateswara Rao

    The need for sustainable and secure nuclear energy is summarized. Driven by economics and public-private partnerships, the technology is evolving. Cost control and regulatory simplification are needed for a nuclear renaissance. Small modular reactors--simple, scalable, and inherently safe--may be the future.

  16. 77 FR 76215 - Small Business Size Regulations, Small Business Innovation Research (SBIR) Program and Small...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-27

    ... overall goal of simplification and maximization of benefits for small businesses, SBA proposed amendments... franchisee. F. Section 121.704--When SBA Determines Size and Eligibility SBA's proposed regulations for the...

  17. Advertising in the Sznajd Marketing Model

    NASA Astrophysics Data System (ADS)

    Schulze, Christian

    The traditional Sznajd model, as well as its Ochrombel simplification for opinion spreading, is applied to marketing with the help of advertising. The larger the lattice, the smaller the amount of advertising is needed to convince the whole market.

  18. Mobile Workforce State Income Tax Simplification Act of 2012

    THOMAS, 112th Congress

    Rep. Coble, Howard [R-NC-6

    2011-05-12

    Senate - 05/16/2012 Received in the Senate and Read twice and referred to the Committee on Finance. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

  19. On the relation between friction losses and pressure pulsations caused by Rotor Stator interaction on the Francis-99 turbine

    NASA Astrophysics Data System (ADS)

    Østby, Petter T. K.; Tore Billdal, Jan; Haugen, Bjørn; Dahlhaug, Ole Gunnar

    2017-01-01

    High head Francis runners are subject to pressure pulsations caused by rotor stator interaction. To ensure safe operation of such turbines, it is important to be able to predict these pulsations. For turbine manufacturers it is often a dilemma whether to perform very advanced and time consuming CFD calculations or to rely on simpler calculations to save development time. This paper tries to evaluate simplifications of the CFD model while still capturing the RSI phenomena and ensuring that the calculation does not underpredict the pressure amplitudes. The effects which turbulence modeling, wall friction, viscosity and mesh have on the pressure amplitudes will be investigated along with time savings with each simplification. The hypothesis is that rotor stator interaction is manly driven by inviscid flow and can therefore be modeled by the Euler equations.

  20. Implementation of Push Recovery Strategy Using Triple Linear Inverted Pendulum Model in “T-FloW” Humanoid Robot

    NASA Astrophysics Data System (ADS)

    Dimas Pristovani, R.; Raden Sanggar, D.; Dadet, Pramadihanto.

    2018-04-01

    Push recovery is one of humanbehaviorwhich is a strategy to defend the body from anexternal force in any environment. This paper describes push recovery strategy which usesMIMO decoupled control system method. The dynamics system uses aquasi-dynamic system based on triple linear inverted pendulum model (TLIPM). The analysis of TLIPMuses zero moment point (ZMP) calculation from ZMP simplification in last research. By using this simplification of dynamics system, the control design can be simplified into 3 serial SISOwith known and uncertain disturbance models in each inverted pendulum. Each pendulum has different plan to damp the external force effect. In this experiment, PID controller (closed- loop)is used to arrange the damp characteristic.The experiment result shows thatwhen using push recovery control strategy (closed-loop control) is about 85.71% whilewithout using push recovery control strategy (open-loop control) it is about 28.57%.

  1. Gradient retention prediction of acid-base analytes in reversed phase liquid chromatography: a simplified approach for acetonitrile-water mobile phases.

    PubMed

    Andrés, Axel; Rosés, Martí; Bosch, Elisabeth

    2014-11-28

    In previous work, a two-parameter model to predict chromatographic retention of ionizable analytes in gradient mode was proposed. However, the procedure required some previous experimental work to get a suitable description of the pKa change with the mobile phase composition. In the present study this previous experimental work has been simplified. The analyte pKa values have been calculated through equations whose coefficients vary depending on their functional group. Forced by this new approach, other simplifications regarding the retention of the totally neutral and totally ionized species also had to be performed. After the simplifications were applied, new prediction values were obtained and compared with the previously acquired experimental data. The simplified model gave pretty good predictions while saving a significant amount of time and resources. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Simplified model of mean double step (MDS) in human body movement

    NASA Astrophysics Data System (ADS)

    Dusza, Jacek J.; Wawrzyniak, Zbigniew M.; Mugarra González, C. Fernando

    In this paper we present a simplified and useful model of the human body movement based on the full gait cycle description, called the Mean Double Step (MDS). It enables the parameterization and simplification of the human movement. Furthermore it allows a description of the gait cycle by providing standardized estimators to transform the gait cycle into a periodical movement process. Moreover the method of simplifying the MDS model and its compression are demonstrated. The simplification is achieved by reducing the number of bars of the spectrum and I or by reducing the number of samples describing the MDS both in terms of reducing their computational burden and their resources for the data storage. Our MDS model, which is applicable to the gait cycle method for examining patients, is non-invasive and provides the additional advantage of featuring a functional characterization of the relative or absolute movement of any part of the body.

  3. A sparsity-based simplification method for segmentation of spectral-domain optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Meiniel, William; Gan, Yu; Olivo-Marin, Jean-Christophe; Angelini, Elsa

    2017-08-01

    Optical coherence tomography (OCT) has emerged as a promising image modality to characterize biological tissues. With axio-lateral resolutions at the micron-level, OCT images provide detailed morphological information and enable applications such as optical biopsy and virtual histology for clinical needs. Image enhancement is typically required for morphological segmentation, to improve boundary localization, rather than enrich detailed tissue information. We propose to formulate image enhancement as an image simplification task such that tissue layers are smoothed while contours are enhanced. For this purpose, we exploit a Total Variation sparsity-based image reconstruction, inspired by the Compressed Sensing (CS) theory, but specialized for images with structures arranged in layers. We demonstrate the potential of our approach on OCT human heart and retinal images for layers segmentation. We also compare our image enhancement capabilities to the state-of-the-art denoising techniques.

  4. Information About Cost of Goods Produced and its Usefulness for Production Engineers - A Case of SME

    NASA Astrophysics Data System (ADS)

    Maruszewska, Ewa Wanda; Strojek-Filus, Marzena; Drábková, Zita

    2017-12-01

    The article stresses the consequences of simplifications implemented in the measurement process of goods produced that are of crucial importance to production engineers in SME. The authors show the variety of possibilities that might be used by financial employees together with probable outputs in terms of valuation distortions. Using the case study the authors emphasis the importance of close cooperation of production engineers with finance professionals as out-puts of finance departments consist an important input for decision-making process of production managers. Further-more, demonstrated deficiencies in terms of methods applicable in financial reporting for measurement of the value of goods produced indicate the need for incorporation more financial and non-financial data in the process of judgments about the final cost of goods produced as simplifications applied in SME distort financial information provided to production engineers.

  5. Effects of head geometry simplifications on acoustic radiation of vowel sounds based on time-domain finite-element simulations.

    PubMed

    Arnela, Marc; Guasch, Oriol; Alías, Francesc

    2013-10-01

    One of the key effects to model in voice production is that of acoustic radiation of sound waves emanating from the mouth. The use of three-dimensional numerical simulations allows to naturally account for it, as well as to consider all geometrical head details, by extending the computational domain out of the vocal tract. Despite this advantage, many approximations to the head geometry are often performed for simplicity and impedance load models are still used as well to reduce the computational cost. In this work, the impact of some of these simplifications on radiation effects is examined for vowel production in the frequency range 0-10 kHz, by means of comparison with radiation from a realistic head. As a result, recommendations are given on their validity depending on whether high frequency energy (above 5 kHz) should be taken into account or not.

  6. Taiwanese life scientists less "medialized" than their Western colleagues.

    PubMed

    Lo, Yin-Yueh; Peters, Hans Peter

    2015-01-01

    The article presents results from surveys of life scientists in Taiwan (n=270) and in Germany (n=326). Fewer Taiwanese than German researchers have frequent contact with the media and they rate their experiences with journalists less positively. Furthermore, they are less prepared to adapt to journalistic expectations and to a greater extent than German researchers they expect journalists to consider scientific criteria in their reporting. These findings are interpreted in Weingart's "medialization of science" framework as indicators of lower medialization of science in Taiwan than in Germany. However, Taiwanese scientists are more willing than German scientists to accept journalistic simplification at the expense of accuracy. This is explained as an adaptation to the media system and to the perceived scientific literacy of the media audience. We hypothesize that cultural differences regarding the relative priority of relational vs. rational communication goals may also contribute to more tolerance of journalistic simplification in Taiwan. © The Author(s) 2013.

  7. Development of the competitive business in the context of environmental legislation in Croatia.

    PubMed

    Matesić, Mirjana; Kalambura, Sanja; Bacun, Dubravka

    2014-03-01

    Environmental protection has a key role in the context of crisis management. It is not just about development of the industry of environmental protection and implementation of new ways of management in innovative solutions in solving problems. Important area of improvement is also revision of environmental legislation aiming at simplification and reduction of costs of procedures for the business. This paper discusses problems of business sector in Croatia related to transposition of demanding environmental EU regulation, it suggests improvements such as simplification of special waste management systems, of environmental impact assessments processes, environmental permitting etc. The paper considers revision of environmental protection not by lowering environmental standards, but by introducing transparent and compromising models between business and environmental protection, based on sustainable development, with control mechanisms which don't impact functioning of business sector (and its competitiveness), therefore allowing successful protection of environment and its renewable and non-renewable resources.

  8. Simplification rules for birdtrack operators

    NASA Astrophysics Data System (ADS)

    Alcock-Zeilinger, J.; Weigert, H.

    2017-05-01

    This paper derives a set of easy-to-use tools designed to simplify calculations with birdtrack operators comprised of symmetrizers and antisymmetrizers. In particular, we present cancellation rules allowing one to shorten the birdtrack expressions of operators and propagation rules identifying the circumstances under which it is possible to propagate symmetrizers past antisymmetrizers and vice versa. We exhibit the power of these simplification rules by means of a short example in which we apply the tools derived in this paper on a typical operator that can be encountered in the representation theory of 𝖲𝖴 (N ) over the product space V⊗m. These rules form the basis for the construction of compact Hermitian Young projection operators and their transition operators addressed in companion papers [J. Alcock-Zeilinger and H. Weigert, "Compact Hermitian Young projection operators," e-print arXiv:1610.10088 [math-ph] and J. Alcock-Zeilinger and H. Weigert, "Transition operators," e-print arXiv:1610.08802 [math-ph

  9. Simplified Model and Response Analysis for Crankshaft of Air Compressor

    NASA Astrophysics Data System (ADS)

    Chao-bo, Li; Jing-jun, Lou; Zhen-hai, Zhang

    2017-11-01

    The original model of crankshaft is simplified to the appropriateness to balance the calculation precision and calculation speed, and then the finite element method is used to analyse the vibration response of the structure. In order to study the simplification and stress concentration for crankshaft of air compressor, this paper compares calculative mode frequency and experimental mode frequency of the air compressor crankshaft before and after the simplification, the vibration response of reference point constraint conditions is calculated by using the simplified model, and the stress distribution of the original model is calculated. The results show that the error between calculative mode frequency and experimental mode frequency is controlled in less than 7%, the constraint will change the model density of the system, the position between the crank arm and the shaft appeared stress concentration, so the part of the crankshaft should be treated in the process of manufacture.

  10. Quantifying the impact of the longitudinal dispersion coefficient parameter uncertainty on the physical transport processes in rivers

    NASA Astrophysics Data System (ADS)

    Camacho Suarez, V. V.; Shucksmith, J.; Schellart, A.

    2016-12-01

    Analytical and numerical models can be used to represent the advection-dispersion processes governing the transport of pollutants in rivers (Fan et al., 2015; Van Genuchten et al., 2013). Simplifications, assumptions and parameter estimations in these models result in various uncertainties within the modelling process and estimations of pollutant concentrations. In this study, we explore both: 1) the structural uncertainty due to the one dimensional simplification of the Advection Dispersion Equation (ADE) and 2) the parameter uncertainty due to the semi empirical estimation of the longitudinal dispersion coefficient. The relative significance of these uncertainties has not previously been examined. By analysing both the relative structural uncertainty of analytical solutions of the ADE, and the parameter uncertainty due to the longitudinal dispersion coefficient via a Monte Carlo analysis, an evaluation of the dominant uncertainties for a case study in the river Chillan, Chile is presented over a range of spatial scales.

  11. Biodiversity hotspots house most undiscovered plant species.

    PubMed

    Joppa, Lucas N; Roberts, David L; Myers, Norman; Pimm, Stuart L

    2011-08-09

    For most organisms, the number of described species considerably underestimates how many exist. This is itself a problem and causes secondary complications given present high rates of species extinction. Known numbers of flowering plants form the basis of biodiversity "hotspots"--places where high levels of endemism and habitat loss coincide to produce high extinction rates. How different would conservation priorities be if the catalog were complete? Approximately 15% more species of flowering plant are likely still undiscovered. They are almost certainly rare, and depending on where they live, suffer high risks of extinction from habitat loss and global climate disruption. By using a model that incorporates taxonomic effort over time, regions predicted to contain large numbers of undiscovered species are already conservation priorities. Our results leave global conservation priorities more or less intact, but suggest considerably higher levels of species imperilment than previously acknowledged.

  12. Antioxidant activity, polyphenolic contents and essential oil composition of Pimpinella anisum L. as affected by zinc fertilizer.

    PubMed

    Tavallali, Vahid; Rahmati, Sadegh; Bahmanzadegan, Atefeh

    2017-11-01

    The antioxidant activity and essential oil content of plants may vary considerably with respect to environmental conditions, especially nutrient availability. Among micronutrients, zinc (Zn) is needed by plants in only small amounts but is crucial to plant development. This study aimed to evaluate the effects of Zn fertilization on the antioxidant activity, polyphenolic contents and essential oil composition of Pimpinella anisum fruit. Foliar application of Zn fertilizer considerably increased the number of detected essential oil components from 27 to 45. Zinc application at a rate of 0.2% (w/v) significantly enhanced the levels of β-bisabolene, germacrene D, n-decane and α-zingiberene, whereas the opposite trend was observed for (E)-anethole and geijerene. Application of 0.2% Zn considerably increased the levels of phenolic compounds, with chlorogenic acid showing the highest content among eight phenolic compounds detected in treated plants. The maximum antioxidant activity was achieved through application of 0.2% Zn fertilizer. These findings indicated that the quality and quantity of anise fruit essential oil components were significantly altered by application of low levels of Zn. After foliar application of Zn, polyphenolic contents as well as antioxidant activity of anise fruit increased. Using Zn fertilizer is an efficient method to improve the pharmaceutical and food properties of anise fruit. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. AP1000{sup R} nuclear power plant safety overview for spent fuel cooling

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

    Gorgemans, J.; Mulhollem, L.; Glavin, J.

    2012-07-01

    The AP1000{sup R} plant is an 1100-MWe class pressurized water reactor with passive safety features and extensive plant simplifications that enhance construction, operation, maintenance, safety and costs. The AP1000 design uses passive features to mitigate design basis accidents. The passive safety systems are designed to function without safety-grade support systems such as AC power, component cooling water, service water or HVAC. Furthermore, these passive features 'fail safe' during a non-LOCA event such that DC power and instrumentation are not required. The AP1000 also has simple, active, defense-in-depth systems to support normal plant operations. These active systems provide the first levelmore » of defense against more probable events and they provide investment protection, reduce the demands on the passive features and support the probabilistic risk assessment. The AP1000 passive safety approach allows the plant to achieve and maintain safe shutdown in case of an accident for 72 hours without operator action, meeting the expectations provided in the U.S. Utility Requirement Document and the European Utility Requirements for passive plants. Limited operator actions are required to maintain safe conditions in the spent fuel pool via passive means. In line with the AP1000 approach to safety described above, the AP1000 plant design features multiple, diverse lines of defense to ensure spent fuel cooling can be maintained for design-basis events and beyond design-basis accidents. During normal and abnormal conditions, defense-in-depth and other systems provide highly reliable spent fuel pool cooling. They rely on off-site AC power or the on-site standby diesel generators. For unlikely design basis events with an extended loss of AC power (i.e., station blackout) or loss of heat sink or both, spent fuel cooling can still be provided indefinitely: - Passive systems, requiring minimal or no operator actions, are sufficient for at least 72 hours under all possible pool heat load conditions. - After 3 days, several different means are provided to continue spent fuel cooling using installed plant equipment as well as off-site equipment with built-in connections. Even for beyond design basis accidents with postulated pool damage and multiple failures in the passive safety-related systems and in the defense-in-depth active systems, the AP1000 multiple spent fuel pool spray and fill systems provide additional lines of defense to prevent spent fuel damage. (authors)« less

  14. Analysis of plant harvest indices for bioregenerative life support systems

    NASA Technical Reports Server (NTRS)

    Velayudhan, A.; Kohlmann, K. L.; Westgate, P. J.; Ladisch, M. R.; Mitchell, C. A. (Principal Investigator)

    1995-01-01

    Harvest indices, which are measures of the ratio of edible to total plant weight, are redefined to include edible sugars derived from enzymatic hydrolysis of the cellulose content of inedible plant components. Compositional analysis and carbohydrate contents of rapeseed, rice, soybeans, cowpea, wheat, sweet potato, white potato, and lettuce were analyzed to develop such generalized harvest indices. Cellulose conversion is shown to extend considerably the food available from plants otherwise grown for their oil and protein content in a bioregenerative life support system.

  15. Impact of harmful algal blooms on several Lake Erie drinking water treatment facilities; methodology considerations

    EPA Science Inventory

    The propagation of cyanbacterial cells and their toxins were investigated at seven drinking water treatment plants (DWTPs) on Lake Erie were investigated with regards to harmful algal bloom (HAB) toxin concentrations, water quality variations in treatment plant influents, and pr...

  16. Tools of the crook – infection strategies of fungal plant pathogens

    USDA-ARS?s Scientific Manuscript database

    Fungi represent an ecologically diverse group of microorganisms that includes plant pathogenic species able to cause considerable yield loses in crop production systems worldwide. In order to establish compatible interactions with their hosts, pathogenic fungi rely on the secretion of molecules of d...

  17. Agricultural Plant Pest Control. Manual 93.

    ERIC Educational Resources Information Center

    Missouri Univ., Columbia. Agricultural Experiment Station.

    This training manual provides information needed to meet the minimum EPA standards for certification as a commercial applicator of pesticides for the agricultural plant pest control category. The text discusses the insect pests including caterpillars, beetles, and soil inhabiting insects; diseases and nematodes; and weeds. Consideration is given…

  18. Conditioned aversion induced by Baccharis coridifolia in sheep and cattle

    USDA-ARS?s Scientific Manuscript database

    In Southern Brazil Baccharis coridifolia is an important toxic plant. The poisoning occurs when animals raised in areas without the plant are transported to, and allowed to graze in, pastures infested by B. coridifolia. Intoxication risk increases considerably when recently transported animals are s...

  19. Conceptual design considerations and neutronics of lithium fall laser fusion target chambers

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

    Meier, W.R.; Thomson, W.B.

    1978-05-31

    Atomics International and Lawrence Livermore Laboratory are involved in the conceptual design of a laser fusion power plant incorporating the lithium fall target chamber. In this paper we discuss some of the more important design considerations for the target chamber and evaluate its nuclear performance. Sizing and configuration of the fall, hydraulic effects, and mechanical design considerations are addressed. The nuclear aspects examined include tritium breeding, energy deposition, and radiation damage.

  20. Bias Momentum Sizing for Hovering Dual-Spin Platforms

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Shin, Jong-Yeob; Moerder, Daniel D.

    2006-01-01

    An atmospheric flight vehicle in hover is typically controlled by varying its thrust vector. Achieving both levitation and attitude control with the propulsion system places considerable demands on it for agility and precision, particularly if the vehicle is statically unstable, or nearly so. These demands can be relaxed by introducing an appropriately sized angular momentum bias aligned with the vehicle's yaw axis, thus providing an additional margin of attitude stability about the roll and pitch axes. This paper describes a methodical approach for trading off angular momentum bias level needed with desired levels of vehicle response due to the design disturbance environment given a vehicle's physical parameters. It also describes several simplifications that provide a more physical and intuitive understanding of dual-spin dynamics for hovering atmospheric vehicles. This approach also mitigates the need for control torques and inadvertent actuator saturation difficulties in trying to stabilize a vehicle via control torques produced by unsteady aerodynamics, thrust vectoring, and unsteady throttling. Simulation results, based on a subscale laboratory test flying platform, demonstrate significant improvements in the attitude control robustness of the vehicle with respect to both wind disturbances and off-center of gravity payload changes during flight.

  1. Patient preference to use a questionnaire varies according to attributes.

    PubMed

    Kim, Na Yae; Richardson, Lyndsay; He, Weilin; Jones, Glenn

    2011-08-01

    Health care professionals may assume questionnaires are burdensome to patients, and this limits their use in clinical settings and promotes simplification. However, patient adherence may improve by optimizing questionnaire attributes and contexts. This cross-sectional survey used Contingent Valuation methods to directly elicit patient preference for conventional monitoring of symptoms, versus adding a tool to monitoring. Under explicit consideration was the 10-question Edmonton Symptom Assessment System (ESAS). In the questionnaire, attributes of ESAS were sequentially altered to try and force preference reversal. A separate group of participants completed both questionnaire and interviews to explore questionnaire reliability, and extend validity. Overall, 24 of 43 participants preferred using ESAS. Most important attributes to preference were frequency, specificity, and complexity. Where preference is initially against ESAS, it may reverse by simplifying the tool and its administrative processes. Interviews in 10 additional participants supported reproducibility and validity of the questionnaire method. Preference for using tools increases when tools are made relevant and used more appropriately. Questionnaires completed by patients as screening tools or aids to communication may be under-utilized. Optimization of ESAS and similar tools may be guided by empirical findings, including those obtained from Contingent Valuation methodologies. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  2. A Digital Microfluidics Platform for Loop-Mediated Isothermal Amplification Detection

    PubMed Central

    Veigas, Bruno; Águas, Hugo; Fortunato, Elvira; Martins, Rodrigo; Baptista, Pedro Viana; Igreja, Rui

    2017-01-01

    Digital microfluidics (DMF) arises as the next step in the fast-evolving field of operation platforms for molecular diagnostics. Moreover, isothermal schemes, such as loop-mediated isothermal amplification (LAMP), allow for further simplification of amplification protocols. Integrating DMF with LAMP will be at the core of a new generation of detection devices for effective molecular diagnostics at point-of-care (POC), providing simple, fast, and automated nucleic acid amplification with exceptional integration capabilities. Here, we demonstrate for the first time the role of coupling DMF and LAMP, in a dedicated device that allows straightforward mixing of LAMP reagents and target DNA, as well as optimum temperature control (reaction droplets undergo a temperature variation of just 0.3 °C, for 65 °C at the bottom plate). This device is produced using low-temperature and low-cost production processes, adaptable to disposable and flexible substrates. DMF-LAMP is performed with enhanced sensitivity without compromising reaction efficacy or losing reliability and efficiency, by LAMP-amplifying 0.5 ng/µL of target DNA in just 45 min. Moreover, on-chip LAMP was performed in 1.5 µL, a considerably lower volume than standard bench-top reactions. PMID:29144379

  3. Ecological Footprint in relation to Climate Change Strategy in Cities

    NASA Astrophysics Data System (ADS)

    Belčáková, Ingrid; Diviaková, Andrea; Belaňová, Eliška

    2017-10-01

    Ecological footprint determines how much natural resources are consumed by an individual, city, region, state or all inhabitants of our planet in order to ensure their requirements and needs. It includes all activities, from food consumption, housing, transport to waste produced and allows us to compare particular activities and their impacts on the environment and natural resources. Ecological footprint is important issue for making sustainable development concept more popular using simplifications, which provide the public with basic information on situation on our planet. Today we know calculations of global (worldwide), national and local ecological footprints. During our research in cities, we were concentrated on calculation of city’s ecological footprint. The article tries to outline theoretical and assumptions and practical results of climate change consequences in cities of Bratislava and Nitra (Slovakia), to describe potential of mitigating adverse impacts of climate change and to provide information for general and professional public on theoretical assumptions in calculating ecological footprint. The intention is to present innovation of ecological footprint calculation, taking into consideration ecological stability of a city (with a specific focus on micro-climate functions of green areas). Present possibilities to reduce ecological footprint are presented.

  4. Accounting for irregular support in spatial interpolation - analysing the effect of using alternative distance measures

    NASA Astrophysics Data System (ADS)

    Skøien, J. O.; Gottschalk, L.; Leblois, E.

    2009-04-01

    Whereas geostatistical and objective methods mostly have been developed for observations with point support or a regular support, e.g. runoff related data can be assumed to have an irregular support in space, and sometimes also a temporal support. The correlations between observations and between observations and the prediction location are found through an integration of a point variogram or point correlation function, a method known as regularisation. Being a relatively simple method for observations with equal and regular support, it can be computationally demanding if the observations have irregular support. With improved speed of computers, solving such integrations has become easier, but there can still be numerical problems that are not easily solved even with high-resolution computations. This can particularly be a problem in hydrological sciences where catchments are overlapping, the correlations are high, and small numerical errors can give ill-posed covariance matrices. The problem increases with increasing number of spatial and/or temporal dimensions. Gottschalk [1993a; 1993b] suggested to replace the integration by a Taylor expansion, hence reducing the computation time considerably, and also expecting less numerical problems with the covariance matrices. In practice, the integrated correlation/semivariance between observations are replaced by correlations/semivariances using the so called Ghosh-distance. Although Gottschalk and collaborators have used the Ghosh-distance also in other papers [Sauquet, et al., 2000a; Sauquet, et al., 2000b], the properties of the simplification have not been examined in detail. Hence, we will here analyse the replacement of the integration by the use of Ghosh-distances, both in sense of the ability to reproduce regularised semivariogram and correlation values, and the influence on the final interpolated maps. Comparisons will be performed both for real observations with a support (hydrological data) and for more hypothetical observations with regular supports where analytical expressions for the regularised semivariances/correlations in some cases can be derived. The results indicate that the simplification is useful for spatial interpolation when the support of the observations has to be taken into account. The difference in semivariogram value or correlation value between the simplified method and the full integration is limited on short distances, increasing for larger distances. However, this is to some degree taken into account while fitting a model for the point process, so that the results after interpolation are less affected by the simplification. The method is of particular use if computation time is of importance, e.g. in the case of real-time mapping procedures. Gottschalk, L. (1993a) Correlation and covariance of runoff, Stochastic Hydrology and Hydraulics, 7, 85-101. Gottschalk, L. (1993b) Interpolation of runoff applying objective methods, Stochastic Hydrology and Hydraulics, 7, 269-281. Sauquet, E., L. Gottschalk, and E. Leblois (2000a) Mapping average annual runoff: a hierarchical approach applying a stochastic interpolation scheme, Hydrological Sciences Journal, 45, 799-815. Sauquet, E., I. Krasovskaia, and E. Leblois (2000b) Mapping mean monthly runoff pattern using EOF analysis, Hydrology and Earth System Sciences, 4, 79-93.

  5. Biofuel Production: Considerations for USACE Civil Works Business Lines

    DTIC Science & Technology

    2014-12-01

    observers to see the big picture by looking at a smaller part of it. Indicators are often quantitative measures such as physical or economic data...however, the end use of collected biomass as feedstock for biofuels is seldom considered. The USACE Aquatic Plant Control Research Program has a ...collection equipment, and proximity to transportation and biofuels processing plants , use of aquatic plant biomass as a feedstock may be warranted

  6. Operating experience feedback report: New plants, Commercial power reactors

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

    Dennig, R.L.; O'Reilly, P.D.

    1987-07-01

    This report documents a detailed review of the cause of unplanned events during the early months of licensed operation for plants licensed between March 1983 and April 1986. The major lessons and corrective actions that appear to have the greatest potential for improving the effectiveness of plant startups are provided for consideration through the operating experience feedback programs and activities of the industry and the NRC staff.

  7. Wood and coal cofiring in Alaska—operational considerations and combustion gas effects for a grate-fired power plant

    Treesearch

    David Nicholls; Zackery Wright; Daisy Huang

    2018-01-01

    Coal is the primary fuel source for electrical power generation in interior Alaska, with more than 600,000 tons burned annually at five different power plants. Woody biomass could be used as part of this fuel mix, offering potential environmental and economic benefits. In this research, debarked chips were cofired with locally mined coal at the Aurora Power Plant...

  8. Disclosure Modernization and Simplification Act of 2014

    THOMAS, 113th Congress

    Rep. Garrett, Scott [R-NJ-5

    2014-05-06

    Senate - 12/03/2014 Received in the Senate and Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

  9. Trading biodiversity for pest problems

    USDA-ARS?s Scientific Manuscript database

    Recent shifts in agricultural practices have resulted in increased pesticide use, land use intensification, and landscape simplification, all of which threaten biodiversity in and near farms. Pests are major challenges to food security, and responses to pests can represent unintended socioeconomic a...

  10. Levels of Simplification. The Use of Assumptions, Restrictions, and Constraints in Engineering Analysis.

    ERIC Educational Resources Information Center

    Whitaker, Stephen

    1988-01-01

    Describes the use of assumptions, restrictions, and constraints in solving difficult analytical problems in engineering. Uses the Navier-Stokes equations as examples to demonstrate use, derivations, advantages, and disadvantages of the technique. (RT)

  11. Habitat management utilizing native wildflowers to foster pollinator abundance

    USDA-ARS?s Scientific Manuscript database

    Pollinators provide essential ecosystem services to agricultural crops, however their population has come under threat globally as a result of intensive agricultural practices and landscape simplification. Designing diverse heterogeneous agricultural landscapes to provide optimal resources serves as...

  12. 26 CFR 1.1081-2 - Purpose and scope of exception.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Commission finds to be necessary or appropriate to effect a simplification or geographical integration of a... cases, and it is intended that the provisions of such part VI, shall not be construed or applied in such...

  13. 78 FR 25787 - Community Connect Broadband Grant Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Learning and Telemedicine Grant Program) during its quarterly Tribal Consultation webinar and... accommodate distance learning, telework, e-government and telemedicine, rural America will see improving... through and beyond completion. 3. Scoring Simplification. The current program scores and ranks...

  14. Characterization of calcium oxalate defective (cod) 6 mutant from Medicago truncatula

    USDA-ARS?s Scientific Manuscript database

    Many plants invest a considerable amount of resources and energy into the formation of calcium oxalate crystals. A number of roles for crystal formation in plant growth and development have been assigned based on their prevalence, spatial distribution, and variety of crystal shapes. These assigned...

  15. A subcontinental view of forest plant invasions

    Treesearch

    Christopher M. Oswalt; Songlin Fei; Qinfeng Guo; Basil V. Iannone III; Sonja N. Oswalt; Bryan C. Pijanowski; Kevin M. Potter

    2015-01-01

    Over the last few decades, considerable attention has focused on small-scale studies of invasive plants and invaded systems. Unfortunately, small scale studies rarely provide comprehensive insight into the complexities of biological invasions at macroscales. Systematic and repeated monitoring of biological invasions at broad scales are rare. In this report, we...

  16. Dominant forest tree mycorrhizal type mediates understory plant invasions

    Treesearch

    Insu Jo; Kevin M. Potter; Grant M. Domke; Songlin Fei

    2017-01-01

    Forest mycorrhizal type mediates nutrient dynamics, which in turn can influence forest community structure and processes. Using forest inventory data, we explored how dominant forest tree mycorrhizal type affects understory plant invasions with consideration of forest structure and soil properties. We found that arbuscular mycorrhizal (AM) dominant forests, which are...

  17. Natural variation at sympathy for the ligule controls penetrance of the semidominant lioguleless narrow-R mutation in Zea mays

    USDA-ARS?s Scientific Manuscript database

    Leaf architecture determines plant structural integrity, light harvesting, and economic considerations such as plant density. Ligules, junctions at the leaf sheath and blade in grasses, protect stalks from environmental stresses and, in conjunction with auricles, controls leaf angle. The liguleless ...

  18. Native plant containers for restoration projects

    Treesearch

    Thomas D. Landis; David E. Steinfeld; R. Kasten Dumroese

    2010-01-01

    The choice of container is one of the most important considerations when growing or ordering native plants for a restoration project. Container characteristics affect not only growth and production efficiencies in the nursery, they can also have important consequences after outplanting. The challenging conditions on restoration sites require containers with...

  19. The History And Future Direction Of Wastewater Treatment Plant Residuals Disinfection And Energy Recovery Considerations

    EPA Science Inventory

    Presentation will review the history of disinfection practices for wastewater treatment plant residuals and discuss both the development and limitations of the U.S. regulations. Present U.S. regulations protect human health by minimizing the contact of humans with infectious mic...

  20. Development and assessment of plant-based synthetic odor baits for surveillance and control of Malaria vectors

    USDA-ARS?s Scientific Manuscript database

    Recent malaria vector control measures have considerably reduced indoor biting mosquito populations. However, reducing the outdoor biting populations remains a challenge because of the unavailability of appropriate lures to achieve this. This study sought to test the efficacy of plant-based syntheti...

  1. NON-TARGET AND ECOSYSTEM IMPACTS FROM GENETICALLY MODIFIED CROPS CONTAINING PLANT INCORPORATED PROTECTANTS (PIPS)

    EPA Science Inventory

    The risk of unintended and unexpected adverse impacts on non-target organisms and ecosystems is a key issue in environmental risk assessment of PIP crop plants. While there has been considerable examination of the effects of insect resistant crops on certain non-target organisms...

  2. PATTERNS OF ALLOZYME DIVERSITY IN THE THREATENED PLANT ERIGERON PARISHII (ASTERACEAE). (R826102)

    EPA Science Inventory

    Thirty-one occurrences of Erigeron parishii, a narrowly endemic plant threatened by mining, were sampled for allozyme diversity. This taxon held considerable genetic variation at the [4 allozyme loci surveyed. Species (e.g., alleles per locus [A] = 4.3 and proportion of polymorph...

  3. Energy analysis of coal, fission, and fusion power plants

    NASA Astrophysics Data System (ADS)

    Tsoulfanidis, N.

    1981-04-01

    The method of net energy analysis has been applied to coal, fission, and fusion power plants. Energy consumption over the lifetime of the plants has been calculated for construction, operation and maintenance, fuel, public welfare, and land use and restoration. Thermal and electric energy requirements were obtained separately for each energy consuming sector. The results of the study are presented in three ways: total energy requirements, energy gain ratio, and payback periods. All three types of power plants are net producers of energy. The coal and fusion power plants are superior to fission plants from the energy efficiency point of view. Fission plants will improve considerably if the centrifuge replaces the gaseous diffusion as a method of enrichment.

  4. An ethnobotanical survey of medicinal plants used in the Siwai and Buin districts of the Autonomous Region of Bougainville.

    PubMed

    Waruruai, Julie; Sipana, Beulah; Koch, Michael; Barrows, Louis R; Matainaho, Teatulohi K; Rai, Prem P

    2011-11-18

    Traditional knowledge of medicinal plant use in many regions of Papua New Guinea and the Autonomous Region of Bougainville is poorly described and rapidly disappearing. A program initiated by the University of Papua New Guinea to systematically document and preserve traditional knowledge of medicinal plant use was initiated with WHO help in 2001. To document and compare medicinal plant use in the Siwai and Buin districts of the Island of Bougainville. Siwai and Buin districts represent two adjacent geographic regions of differing language traditions. This report is a combination of two University of Papua New Guinea reports generated using a University of Papua New Guinea and Papua New Guinea Department of Health approved survey questionnaire "Information sheet on traditional herbal reparations and medicinal plants of Papua New Guinea". Although Siwai and Buin districts are adjacent in Southern Bougainville, there is considerable variation in the specific plants used medicinally and the specific uses of those plants that are used commonly in the two regions. In addition, many of the plants used in the region are widely distributed species that are used medicinally in other settings. Nevertheless, the high endemicity of plants and the extraordinary cultural diversity in the Autonomous Region of Bougainville has yielded description of the medicinal use of many plants that have not previously been reported in the wider scientific literature. Efforts to document and preserve traditional knowledge of plant use in Papua New Guinea have yielded important new records of plants with potential application in the provision of health care for a developing nation with an under developed Western style rural health care system. This report documents substantial commonality in the general modes of medicinal plant preparation and in the health care applications of plant use in the Siwai and Buin traditions, however, there was considerable difference noted in the particular uses of the specific plants used in one or another of the districts. Copyright © 2011. Published by Elsevier Ireland Ltd.

  5. The endoplasmic reticulum in plant immunity and cell death

    PubMed Central

    Eichmann, Ruth; Schäfer, Patrick

    2012-01-01

    The endoplasmic reticulum (ER) is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane, or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programed cell death (PCD) in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signaling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants. PMID:22936941

  6. The endoplasmic reticulum in plant immunity and cell death.

    PubMed

    Eichmann, Ruth; Schäfer, Patrick

    2012-01-01

    The endoplasmic reticulum (ER) is a highly dynamic organelle in eukaryotic cells and a major production site of proteins destined for vacuoles, the plasma membrane, or apoplast in plants. At the ER, these secreted proteins undergo multiple processing steps, which are supervised and conducted by the ER quality control system. Notably, processing of secreted proteins can considerably elevate under stress conditions and exceed ER folding capacities. The resulting accumulation of unfolded proteins is defined as ER stress. The efficiency of cells to re-establish proper ER function is crucial for stress adaptation. Besides delivering proteins directly antagonizing and resolving stress conditions, the ER monitors synthesis of immune receptors. This indicates the significance of the ER for the establishment and function of the plant immune system. Recent studies point out the fragility of the entire system and highlight the ER as initiator of programed cell death (PCD) in plants as was reported for vertebrates. This review summarizes current knowledge on the impact of the ER on immune and PCD signaling. Understanding the integration of stress signals by the ER bears a considerable potential to optimize development and to enhance stress resistance of plants.

  7. 75 FR 33653 - Connecticut Yankee Atomic Power Company; Notice of Consideration of Issuance of Amendment to...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-14

    ... Company; Notice of Consideration of Issuance of Amendment to Facility Operating License, Proposed No... Commission (the Commission) is considering issuance of an amendment to Facility Operating License No. DPR-61... Security Plan in the Haddam Neck Facility Operating License from the ``Haddam Neck Plant Defueled Physical...

  8. 75 FR 19428 - Palisades Nuclear Plant; Notice of Consideration of Issuance of Amendment to Facility Operating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-14

    ... of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant... (NRC or the Commission) is considering issuance of an amendment to Facility Operating License No. DPR... (SSC) or change the way any SSC is operated. The proposed license condition does not involve operation...

  9. 75 FR 70708 - Palisades Nuclear Plant; Notice of Consideration of Issuance of Amendment to Facility Operating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-18

    ... of Consideration of Issuance of Amendment to Facility Operating License, Proposed No Significant... (NRC, the Commission) is considering issuance of an amendment to Facility Operating License No. DPR-20... PNP Renewed Facility Operating License. The change would remove the name of the former operator of the...

  10. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  11. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  12. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  13. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  14. 40 CFR 194.53 - Consideration of underground sources of drinking water.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Consideration of underground sources of drinking water. 194.53 Section 194.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS CRITERIA FOR THE CERTIFICATION AND RE-CERTIFICATION OF THE WASTE ISOLATION PILOT PLANT'S COMPLIANCE WITH THE...

  15. 40 CFR 194.53 - Consideration of underground sources of drinking water.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Consideration of underground sources of drinking water. 194.53 Section 194.53 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) RADIATION PROTECTION PROGRAMS CRITERIA FOR THE CERTIFICATION AND RE-CERTIFICATION OF THE WASTE ISOLATION PILOT PLANT'S COMPLIANCE WITH THE...

  16. ALARA radiation considerations for the AP600 reactor

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

    Lau, F.L.

    1995-03-01

    The radiation design of the AP600 reactor plant is based on an average annual occupational radiation exposure (ORE) of 100 man-rem. As a design goal we have established a lower value of 70 man-rem per year. And, with our current design process, we expect to achieve annual exposures which are well below this goal. To accomplish our goal we have established a process that provides criteria, guidelines and customer involvement to achieve the desired result. The criteria and guidelines provide the shield designer, as well as the systems and plant layout designers with information that will lead to an integratedmore » plant design that minimizes personnel exposure and yet is not burdened with complicated shielding or unnecessary component access limitations. Customer involvement is provided in the form of utility input, design reviews and information exchange. Cooperative programs with utilities in the development of specific systems or processes also provides for an ALARA design. The results are features which include ALARA radiation considerations as an integral part of the plant design and a lower plant ORE. It is anticipated that a further reduction in plant personnel exposures will result through good radiological practices by the plant operators. The information in place to support and direct the plant designers includes the Utility Requirements Document (URD), Federal Regulations, ALARA guidelines, radiation design information and radiation and shielding design criteria. This information, along with the utility input, design reviews and information feedback, will contribute to the reduction of plant radiation exposure levels such that they will be less than the stated goals.« less

  17. Natural gas operations: considerations on process transients, design, and control.

    PubMed

    Manenti, Flavio

    2012-03-01

    This manuscript highlights tangible benefits deriving from the dynamic simulation and control of operational transients of natural gas processing plants. Relevant improvements in safety, controllability, operability, and flexibility are obtained not only within the traditional applications, i.e. plant start-up and shutdown, but also in certain fields apparently time-independent such as the feasibility studies of gas processing plant layout and the process design of processes. Specifically, this paper enhances the myopic steady-state approach and its main shortcomings with respect to the more detailed studies that take into consideration the non-steady state behaviors. A portion of a gas processing facility is considered as case study. Process transients, design, and control solutions apparently more appealing from a steady-state approach are compared to the corresponding dynamic simulation solutions. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  18. The Source of Tok Pisin Structures.

    ERIC Educational Resources Information Center

    Goulden, Rick J.

    1989-01-01

    The source of the similarities and differences produced by pidginization is a central question studied in Pidgin-Creole linguistics. Several explanatory approaches are discussed that have guided research in this area, including simplification, substratum, independent innovation, and universals. (27 references) (Author/OD)

  19. Ecological enrichment in agroecosystems: Utilizing wildflowers to promote beneficial arthropod communities

    USDA-ARS?s Scientific Manuscript database

    Beneficial arthropods which provide important ecosystems services have come under threat as a result of intensive agricultural practices and landscape simplification. Engineering diverse heterogeneous agricultural landscapes to provide optimal resources for beneficial arthropods may recover and enha...

  20. Zoology: The Walking Heads.

    PubMed

    Maderspacher, Florian

    2016-03-07

    An analysis of Hox genes reveals that the body of the adorably weird tardigrades is essentially a truncated front end. This illustrates that loss and simplification are a hallmark of the evolution of animal body plans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Implementation of Alabama Resources Information System, ARIS

    NASA Technical Reports Server (NTRS)

    Herring, B. E.

    1978-01-01

    Development of ARIS - Alabama Resources Information System is summarized. Development of data bases, system simplification for user access, and making information available to personnel having a need to use ARIS or in the process of developing ARIS type systems are discussed.

  2. Legally high? Legal considerations of Salvia divinorum.

    PubMed

    Griffin, O Hayden; Miller, Bryan Lee; Khey, David N

    2008-06-01

    The legal status of the hallucinogenic plant Salvia divinorum has been rapidly changing. Legal prohibitions on this plant native to Oaxaca, Mexico have emerged at the state level, a phenomenon that has not occurred since the passage of the Controlled Substances Act (CSA). Included will be a brief description of the plant that has only recently crept into the popular American consciousness, and a review of the different legal mechanisms through which states have controlled the plant and the pending legislation proposing controls. Lastly, the implications of various state laws are discussed.

  3. Quiet planting in the locked constraints satisfaction problems

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

    Zdeborova, Lenka; Krzakala, Florent

    2009-01-01

    We study the planted ensemble of locked constraint satisfaction problems. We describe the connection between the random and planted ensembles. The use of the cavity method is combined with arguments from reconstruction on trees and first and second moment considerations; in particular the connection with the reconstruction on trees appears to be crucial. Our main result is the location of the hard region in the planted ensemble, thus providing hard satisfiable benchmarks. In a part of that hard region instances have with high probability a single satisfying assignment.

  4. How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau

    PubMed Central

    Liu, Yang; Xiao, Li; Huang, Yimei

    2017-01-01

    Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures. PMID:28946681

  5. How Fencing Affects the Soil Quality and Plant Biomass in the Grassland of the Loess Plateau.

    PubMed

    Zeng, Quanchao; Liu, Yang; Xiao, Li; Huang, Yimei

    2017-09-25

    Overgrazing is a severe problem in several regions in Northwestern China and has caused serious land degradation. Secondary natural succession plays an important role in the accumulation of soil carbon and nitrogen contents. Estimating the effects of grazing exclusion on soil quality and plant diversity will improve our understanding of the succession process after overgrazing and promote judicious management of degraded pastures. This experiment was designed to measure soil properties and plant diversity following an age chronosequence of grasslands (ages ranged from one year, 12 years, 20 years, and 30 years) in Northwestern China. The results showed that continuous fencing resulted in a considerable increase in plant coverage, plant biomass (above- and below-ground biomass), and plant diversity, which can directly or indirectly improve the accumulation of soil organic carbon and total nitrogen content. The plant coverage and the above- and below-ground biomass linearly increased along the succession time, whereas soil organic C and N contents showed a significant decline in the first 12 years and, subsequently, a significant increase. The increased plant biomass caused an increase in soil organic carbon and soil total nitrogen. These results suggested that soil restoration and plant cover were an incongruous process. Generally, soil restoration is a slow process and falls behind vegetation recovery after grazing exclusion. Although the accumulation of soil C and N stocks needed a long term, vegetation restoration was a considerable option for the degraded grassland due to the significant increase of plant biomass, diversity, and soil C and N stocks. Therefore, fencing with natural succession should be considered in the design of future degraded pastures.

  6. Parametric study of potential early commercial MHD power plants. Task 3: Parameter variation of plant size

    NASA Technical Reports Server (NTRS)

    Hals, F. A.

    1981-01-01

    Plants with a nominal output of 200 and 500 MWe and conforming to the same design configuration as the Task II plant were investigated. This information is intended to permit an assessment of the competitiveness of first generation MHD/steam plants with conventional steam plants over the range of 200 to 1000 MWe. The results show that net plant efficiency of the MHD plant is significantly higher than a conventional steam plant of corresponding size. The cost of electricity is also less for the MHD plant over the entire plant size range. As expected, the cost differential is higher for the larger plant and decreases with plant size. Even at the 200 MWe capacity, however, the differential in COE between the MHD plant and the conventional plant is sufficient attractive to warrant serious consideration. Escalating fuel costs will enhance the competitive position of MHD plants because they can utilize the fuel more efficiently than conventional steam plants.

  7. Growing media [Chapter 5

    Treesearch

    Douglass F. Jacobs; Thomas D. Landis; Tara Luna

    2009-01-01

    Selecting the proper growing medium is one of the most important considerations in nursery plant production. A growing medium can be defined as a substance through which roots grow and extract water and nutrients. In native plant nurseries, a growing medium can consist of native soil but is more commonly an "artificial soil" composed of materials such as peat...

  8. Dominant forest tree mycorrhizal type mediates understory plant invasions

    Treesearch

    Insu Jo; Kevin M. Potter; Grant M. Domke; Songlin Fei

    2018-01-01

    Forest mycorrhizal type mediates nutrient dynamics, which in turn can influence forest community structure and processes. Using forest inventory data, we explored how dominant forest tree myc- orrhizal type affects understory plant invasions with consideration of forest structure and soil properties. We found that arbuscular mycorrhizal (AM) dominant forests, which are...

  9. Ecological zones in the Southern Appalachians: first approximation

    Treesearch

    Steven A. Simon; Thomas K. Collins; Gary L. Kauffman; W. Henry McNab; Christopher J. Ulrey

    2005-01-01

    Forest environments of the Southern Appalachian Mountains and their characteristic plant communities are among the most varied in the Eastern United States. Considerable data are available on the distribution of plant communities relative to temperature and moisture regimes, but not much information on fertility as an environmental influence has been published; nor has...

  10. Riparian Plant Water Relations Along the North Fork Kings River, California

    Treesearch

    Janet L. Nachlinger; Stanley D. Smith; Roland J. Risser

    1989-01-01

    Plant water relations of five obligate riparian species were studied along California's North Fork Kings River. Diurnal stomatal conductance, transpiration, and xylem pressure potentials were measured throughout the 1986 growing season and in mid-season in 1987. Patterns were similar for all species although absolute values varied considerably. Maximum stomatal...

  11. Designing and using phenological studies to define management strategies for aquatic plants

    USDA-ARS?s Scientific Manuscript database

    Scientists and managers alike have recognized that weed management activities in the past were timed more for the convenience of the applicator or response of the resource manager than in consideration of the biology of the target plant. A thorough understanding of the life history and phenology of...

  12. Analysis of terpenoid aldehydes related to insect herbivory in new germplasm line with a high (+)-to(-)- gossypol isomer ratio

    USDA-ARS?s Scientific Manuscript database

    Gossypol is present in cotton plants in two enantiomeric forms, (+)- and (-)-gossypol. The ratios of these enantiomers vary considerably among Gossypium species and between different plant tissues. Cotton seeds are commonly used as animal feed only for ruminants because (-)-gossypol is highly toxi...

  13. Economic importance, taxonomic representation and scientific priority as drivers of genome sequencing projects.

    PubMed

    Vallée, Geneviève C; Muñoz, Daniella Santos; Sankoff, David

    2016-11-11

    Of the approximately two hundred sequenced plant genomes, how many and which ones were sequenced motivated by strictly or largely scientific considerations, and how many by chiefly economic, in a wide sense, incentives? And how large a role does publication opportunity play? In an integration of multiple disparate databases and other sources of information, we collect and analyze data on the size (number of species) in the plant orders and families containing sequenced genomes, on the trade value of these species, and of all the same-family or same-order species, and on the publication priority within the family and order. These data are subjected to multiple regression and other statistical analyses. We find that despite the initial importance of model organisms, it is clearly economic considerations that outweigh others in the choice of genome to be sequenced. This has important implications for generalizations about plant genomes, since human choices of plants to harvest (and cultivate) will have incurred many biases with respect to phenotypic characteristics and hence of genomic properties, and recent genomic evolution will also have been affected by human agricultural practices.

  14. Microprocessor-based control systems application in nuclear power plant critical systems

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

    Shah, M.R.; Nowak, J.B.

    Microprocessor-based control systems have been used in fossil power plants and are receiving greater acceptance for application in nuclear plants. This technology is not new but it does require unique considerations when applied to nuclear power plants. Sargent and Lundy (S and L) has used a microprocessor-based component logic control system (interposing Logic System) for safety- and non-safety-related components in nuclear power plants under construction overseas. Currently, S and L is in the design stage to replace an existing analog control system with a microprocessor-based control system in the U.S. The trend in the industry is to replace systems inmore » existing plants or design new power plants with microprocessor-based control systems.« less

  15. New Trends and Perspectives in the Evolution of Neurotransmitters in Microbial, Plant, and Animal Cells.

    PubMed

    Roshchina, Victoria V

    2016-01-01

    The evolutionary perspective on the universal roles of compounds known as neurotransmitters may help in the analysis of relations between all organisms in biocenosis-from microorganisms to plant and animals. This phenomenon, significant for chemosignaling and cellular endocrinology, has been important in human health and the ability to cause disease or immunity, because the "living environment" influences every organism in a biocenosis relationship (microorganism-microorganism, microorganism-plant, microorganism-animal, plant-animal, plant-plant and animal-animal). Non-nervous functions of neurotransmitters (rather "biomediators" on a cellular level) are considered in this review and ample consideration is given to similarities and differences that unite, as well as distinguish, taxonomical kingdoms.

  16. Flood analyses for Department of Energy Y-12, ORNL and K-25 Plants. Flood analyses in support of flood emergency planning

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

    NONE

    1995-05-01

    The study involved defining the flood potential and local rainfall depth and duration data for the Department of Energy`s (DOE) Y-12, Oak Ridge National Laboratory (ORNL), and K-25 plants. All three plants are subject to flooding from the Clinch River. In addition, the Y-12 plant is subject to flooding from East Fork Poplar and Bear Creeks, the ORNL plant from Whiteoak Creek and Melton Branch, and the K-25 plant from Poplar Creek. Determination of flood levels included consideration of both rainfall events and postulated failures of Norris and Melton Hill Dams in seismic events.

  17. A finite difference scheme for the equilibrium equations of elastic bodies

    NASA Technical Reports Server (NTRS)

    Phillips, T. N.; Rose, M. E.

    1984-01-01

    A compact difference scheme is described for treating the first-order system of partial differential equations which describe the equilibrium equations of an elastic body. An algebraic simplification enables the solution to be obtained by standard direct or iterative techniques.

  18. Clarifying Normalization

    ERIC Educational Resources Information Center

    Carpenter, Donald A.

    2008-01-01

    Confusion exists among database textbooks as to the goal of normalization as well as to which normal form a designer should aspire. This article discusses such discrepancies with the intention of simplifying normalization for both teacher and student. This author's industry and classroom experiences indicate such simplification yields quicker…

  19. Counting Penguins.

    ERIC Educational Resources Information Center

    Perry, Mike; Kader, Gary

    1998-01-01

    Presents an activity on the simplification of penguin counting by employing the basic ideas and principles of sampling to teach students to understand and recognize its role in statistical claims. Emphasizes estimation, data analysis and interpretation, and central limit theorem. Includes a list of items for classroom discussion. (ASK)

  20. 45 CFR 672.12 - Prehearing conference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT... consider: (1) The settlement of the case; (2) The simplification of issues and stipulation of facts not in..., documents, prepared testimony, and admissions or stipulations of fact which will avoid unnecessary proof; (5...

  1. 45 CFR 672.12 - Prehearing conference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT... consider: (1) The settlement of the case; (2) The simplification of issues and stipulation of facts not in..., documents, prepared testimony, and admissions or stipulations of fact which will avoid unnecessary proof; (5...

  2. 45 CFR 672.12 - Prehearing conference.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT... consider: (1) The settlement of the case; (2) The simplification of issues and stipulation of facts not in..., documents, prepared testimony, and admissions or stipulations of fact which will avoid unnecessary proof; (5...

  3. 45 CFR 672.12 - Prehearing conference.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT... consider: (1) The settlement of the case; (2) The simplification of issues and stipulation of facts not in..., documents, prepared testimony, and admissions or stipulations of fact which will avoid unnecessary proof; (5...

  4. 45 CFR 672.12 - Prehearing conference.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION ENFORCEMENT... consider: (1) The settlement of the case; (2) The simplification of issues and stipulation of facts not in..., documents, prepared testimony, and admissions or stipulations of fact which will avoid unnecessary proof; (5...

  5. 77 FR 56814 - Notice of Telephonic Prehearing Conference

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-14

    ... Conference AGENCY: U.S. Consumer Product Safety Commission. ACTION: Notice. SUMMARY: Notice of telephonic...) Petitions for leave to intervene; (2) Motions, including motions for consolidation of proceedings and for certification of class actions; (3) Identification, simplification and clarification of the issues; (4...

  6. Culturing Chick Embryos--A Simplification of New's Method.

    ERIC Educational Resources Information Center

    Downie, J. R.

    1979-01-01

    Describes a simplified version of New's method for culturing early chick embryos. The technique allows continuous observation of the critical first three days of development and the conditions for setting up successful cultures are also presented to help both teachers and students. (HM)

  7. Simple landscape modifications for pollinator and arthropod natural enemy enhancement

    USDA-ARS?s Scientific Manuscript database

    Beneficial arthropods which play an important role in providing ecosystem services (pollination and pest control) have come under threat as a result of intensive agricultural practices and simplification of habitats. Ecological intensification in agricultural landscapes by diversifying the habitat r...

  8. The Words of Children's Television.

    ERIC Educational Resources Information Center

    Rice, Mabel L.

    1984-01-01

    Dialog features--communication flow, language structures, and meaning/content--and nonverbal formal features of six children's television programs are examined to determine if there is dialog simplification, if certain dialog characteristics differentiate among shows sampled, and if there are different combinations of linguistic features and…

  9. Small Business Mergers, Acquisitions, Sales, and Brokerage Simplification Act of 2014

    THOMAS, 113th Congress

    Rep. Huizenga, Bill [R-MI-2

    2013-06-06

    Senate - 01/15/2014 Received in the Senate and Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status Passed HouseHere are the steps for Status of Legislation:

  10. Advanced Computing for Science.

    ERIC Educational Resources Information Center

    Hut, Piet; Sussman, Gerald Jay

    1987-01-01

    Discusses some of the contributions that high-speed computing is making to the study of science. Emphasizes the use of computers in exploring complicated systems without the simplification required in traditional methods of observation and experimentation. Provides examples of computer assisted investigations in astronomy and physics. (TW)

  11. The effect of plant water storage on water fluxes within the coupled soil-plant system [The role of plant water storage on water fluxes within the coupled soil-plant system

    DOE PAGES

    Huang, Cheng -Wei; Domec, Jean -Christophe; Ward, Eric J.; ...

    2016-11-21

    In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil–plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. Here, the model numerically resolves soil–plant hydrodynamics by coupling them to leaf-level gas exchange and soil–root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (F e,night) on hydraulic redistribution (HR) in the soil.

  12. The effect of plant water storage on water fluxes within the coupled soil-plant system [The role of plant water storage on water fluxes within the coupled soil-plant system

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

    Huang, Cheng -Wei; Domec, Jean -Christophe; Ward, Eric J.

    In addition to buffering plants from water stress during severe droughts, plant water storage (PWS) alters many features of the spatio-temporal dynamics of water movement in the soil–plant system. How PWS impacts water dynamics and drought resilience is explored using a multi-layer porous media model. Here, the model numerically resolves soil–plant hydrodynamics by coupling them to leaf-level gas exchange and soil–root interfacial layers. Novel features of the model are the considerations of a coordinated relationship between stomatal aperture variation and whole-system hydraulics and of the effects of PWS and nocturnal transpiration (F e,night) on hydraulic redistribution (HR) in the soil.

  13. A simple graphical method for measuring inherent safety.

    PubMed

    Gupta, J P; Edwards, David W

    2003-11-14

    Inherently safer design (ISD) concepts have been with us for over two decades since their elaboration by Kletz [Chem. Ind. 9 (1978) 124]. Interest has really taken off globally since the early nineties after several major mishaps occurred during the eighties (Bhopal, Mexico city, Piper-alfa, Philips Petroleum, to name a few). Academic and industrial research personnel have been actively involved into devising inherently safer ways of production. The regulatory bodies have also shown deep interest since ISD makes the production safer and hence their tasks easier. Research funding has also been forthcoming for new developments as well as for demonstration projects.A natural question that arises is as to how to measure ISD characteristics of a process? Several researchers have worked on this [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Inherent safety in process plant design, Ph.D. Thesis, VTT Publication Number 384, Helsinki University of Technology, Espoo, Finland, 1999; Proceedings of the Mary Kay O'Connor Process Safety Center Symposium, 2001, p. 509]. Many of the proposed methods are very elegant, yet too involved for easy adoption by the industry which is scared of yet another safety analysis regime. In a recent survey [Trans. IChemE, Process Safety Environ. Prog. B 80 (2002) 115], companies desired a rather simple method to measure ISD. Simplification is also an important characteristic of ISD. It is therefore desirable to have a simple ISD measurement procedure. The ISD measurement procedure proposed in this paper can be used to differentiate between two or more processes for the same end product. The salient steps are: Consider each of the important parameters affecting the safety (e.g., temperature, pressure, toxicity, flammability, etc.) and the range of possible values these parameters can have for all the process routes under consideration for an end product. Plot these values for each step in each process route and compare. No addition of values for disparate hazards (temperature, pressure, inventory, toxicity, flammability, etc.) is being suggested to derive an overall ISD index value since that conceals the effects of different parameters. Further, addition of numbers with different units ( degrees C for temperature, atm/bar for pressure, t for inventory, etc.) is inappropriate in scientific sense. The proposed approach has a major advantage of expanding consideration in future to incorporate economic, regulatory, pollution control and worker health aspects, as well as factors such as the experience one has or 'the comfort level' one feels with each of the processes under consideration. Additionally, it would also guide the designers and decision makers into affecting specific changes in the processes to reduce the unsafe features. We demonstrate our simple approach by using the example of six routes to make methyl methacrylate as documented by Edwards and Lawrence [Trans. IChemE, Process Safety Environ. Protect. B 71 (4) (1993) 252; Quantifying inherent safety of chemical process routes, Ph.D. Thesis, Loughborough University, Loughborough, UK, 1996] and show that the decision could well have been different if addition of disparate hazards had not been done.

  14. A study of the bacterial community in the root system of the maytansine containing plant Putterlickia verrucosa.

    PubMed

    Wings, Susanne; Müller, Henry; Berg, Gabriele; Lamshöft, Marc; Leistner, Eckhard

    2013-07-01

    Maytansinoid compounds are ansa antibiotics occurring in the bacterium Actinosynnema pretiosum, in mosses and in higher plants such as Putterlickia verrucosa (E. Meyer ex Sonder) Szyszyl. The disjunct occurrence of maytansinoids has led to the consideration that plant-associated bacteria may be responsible for the presence of maytansinoids in P. verrucosa plants. Investigation of the bacterial community of this plant by molecular methods led to the observation that A. pretiosum, a maytansine-producing bacterium, is likely to be an inhabitant of the rhizosphere and the endorhiza of P. verrucosa. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Controlled activation of retrotransposition for plant breeding.

    PubMed

    Paszkowski, Jerzy

    2015-04-01

    Plant genomes consist to a large extent of transposable elements (TEs), predominantly retrotransposons. Their accumulation through periodic transposition bursts has shaped the structure and regulatory organization of plant genomes, often contributing to phenotypic traits. Transposon-generated phenotypes selected by humans during plant domestication have been maintained under strict selection during subsequent plant breeding. Our knowledge of the epigenetic, environmental, and developmental regulation of TE activity has advanced considerably in recent years. Here I will consider TEs as an attractive endogenous source of genetic variation that can be liberated in a controlled fashion and thus offer novel phenotypic diversity to be selected for crop improvement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. How do type II topoisomerases use ATP hydrolysis to simplify DNA topology beyond equilibrium? Investigating the relaxation reaction of non-supercoiling type II topoisomerases

    PubMed Central

    Stuchinskaya, Tanya; Mitchenall, Lesley A.; Schoeffler, Allyn J.; Corbett, Kevin D.; Berger, James M.; Bates, Andrew D.; Maxwell, Anthony

    2015-01-01

    DNA topoisomerases control the topology of DNA (e.g. the level of supercoiling) in all cells. Type IIA topoisomerases are ATP-dependent enzymes that have been shown to simplify the topology of their DNA substrates to a level beyond that expected at equilibrium (i.e. more relaxed than the product of relaxation by ATP-independent enzymes, such as type I topoisomerases, or a lower than equilibrium level of catenation). The mechanism of this effect is currently unknown, although several models have been suggested. We have analysed the DNA relaxation reactions of type II topoisomerases to further explore this phenomenon. We find that all type IIA topoisomerases tested exhibit the effect to a similar degree and that it is not dependent on the C-terminal domains of the enzymes. As recently reported, the type IIB topoisomerase, topo VI (which is only distantly related to the type IIA enzymes), does not exhibit topology simplification. We find that topology simplification is not significantly dependent on circle size in the range ~2–9 kbp, and is not altered by reducing the free energy available from ATP hydrolysis by varying the ATP:ADP ratio. A direct test of one model (DNA tracking, i.e. sliding of a protein clamp along DNA to trap supercoils) suggests that this is unlikely to be the explanation for the effect. We conclude that geometric selection of DNA segments by the enzymes is likely to be a primary source of the effect but that it is possible that other factors contribute. We also speculate whether topology simplification might simply be an evolutionary relic, with no adaptive significance. PMID:19094994

  17. How do type II topoisomerases use ATP hydrolysis to simplify DNA topology beyond equilibrium? Investigating the relaxation reaction of nonsupercoiling type II topoisomerases.

    PubMed

    Stuchinskaya, Tanya; Mitchenall, Lesley A; Schoeffler, Allyn J; Corbett, Kevin D; Berger, James M; Bates, Andrew D; Maxwell, Anthony

    2009-02-06

    DNA topoisomerases control the topology of DNA (e.g., the level of supercoiling) in all cells. Type IIA topoisomerases are ATP-dependent enzymes that have been shown to simplify the topology of their DNA substrates to a level beyond that expected at equilibrium (i.e., more relaxed than the product of relaxation by ATP-independent enzymes, such as type I topoisomerases, or a lower-than-equilibrium level of catenation). The mechanism of this effect is currently unknown, although several models have been suggested. We have analyzed the DNA relaxation reactions of type II topoisomerases to further explore this phenomenon. We find that all type IIA topoisomerases tested exhibit the effect to a similar degree and that it is not dependent on the supercoil-sensing C-terminal domains of the enzymes. As recently reported, the type IIB topoisomerase, topoisomerase VI (which is only distantly related to type IIA enzymes), does not exhibit topology simplification. We find that topology simplification is not significantly dependent on circle size in the range approximately 2-9 kbp and is not altered by reducing the free energy available from ATP hydrolysis by varying the ADP:ATP ratio. A direct test of one model (DNA tracking; i.e., sliding of a protein clamp along DNA to trap supercoils) suggests that this is unlikely to be the explanation for the effect. We conclude that geometric selection of DNA segments by the enzymes is likely to be a primary source of the effect, but that it is possible that other kinetic factors contribute. We also speculate whether topology simplification might simply be an evolutionary relic, with no adaptive significance.

  18. Four Common Simplifications of Multi-Criteria Decision Analysis do not hold for River Rehabilitation

    PubMed Central

    2016-01-01

    River rehabilitation aims at alleviating negative effects of human impacts such as loss of biodiversity and reduction of ecosystem services. Such interventions entail difficult trade-offs between different ecological and often socio-economic objectives. Multi-Criteria Decision Analysis (MCDA) is a very suitable approach that helps assessing the current ecological state and prioritizing river rehabilitation measures in a standardized way, based on stakeholder or expert preferences. Applications of MCDA in river rehabilitation projects are often simplified, i.e. using a limited number of objectives and indicators, assuming linear value functions, aggregating individual indicator assessments additively, and/or assuming risk neutrality of experts. Here, we demonstrate an implementation of MCDA expert preference assessments to river rehabilitation and provide ample material for other applications. To test whether the above simplifications reflect common expert opinion, we carried out very detailed interviews with five river ecologists and a hydraulic engineer. We defined essential objectives and measurable quality indicators (attributes), elicited the experts´ preferences for objectives on a standardized scale (value functions) and their risk attitude, and identified suitable aggregation methods. The experts recommended an extensive objectives hierarchy including between 54 and 93 essential objectives and between 37 to 61 essential attributes. For 81% of these, they defined non-linear value functions and in 76% recommended multiplicative aggregation. The experts were risk averse or risk prone (but never risk neutral), depending on the current ecological state of the river, and the experts´ personal importance of objectives. We conclude that the four commonly applied simplifications clearly do not reflect the opinion of river rehabilitation experts. The optimal level of model complexity, however, remains highly case-study specific depending on data and resource availability, the context, and the complexity of the decision problem. PMID:26954353

  19. Omeprazole Attenuates Pulmonary Aryl Hydrocarbon Receptor Activation and Potentiates Hyperoxia-Induced Developmental Lung Injury in Newborn Mice.

    PubMed

    Shivanna, Binoy; Zhang, Shaojie; Patel, Ananddeep; Jiang, Weiwu; Wang, Lihua; Welty, Stephen E; Moorthy, Bhagavatula

    2015-11-01

    Hyperoxia contributes to the development of bronchopulmonary dysplasia (BPD) in human preterm infants and a similar lung phenotype characterized by alveolar simplification in newborn mice. Omeprazole (OM) is a proton pump inhibitor that is used to treat humans with gastric acid related disorders. OM-mediated aryl hydrocarbon receptor (AhR) activation attenuates acute hyperoxic lung injury (HLI) in adult mice. Whether OM activates pulmonary AhR and protects C57BL/6J newborn mice against hyperoxia-induced developmental lung (alveolar and pulmonary vascular simplification, inflammation, and oxidative stress) injury (HDLI) is unknown. Therefore, we tested the hypothesis that OM will activate pulmonary AhR and mitigate HDLI in newborn mice. Newborn mice were treated daily with i.p. injections of OM at doses of 10 (OM10) or 25 (OM25) mg/kg while being exposed to air or hyperoxia (FiO2 of 85%) for 14 days, following which their lungs were harvested to determine alveolarization, pulmonary vascularization, inflammation, oxidative stress, vascular injury, and AhR activation. To our surprise, hyperoxia-induced alveolar and pulmonary vascular simplification, inflammation, oxidative stress, and vascular injury were augmented in OM25-treated animals. These findings were associated with attenuated pulmonary vascular endothelial growth factor receptor 2 expression and decreased pulmonary AhR activation in the OM25 group. We conclude that contrary to our hypothesis, OM decreases functional activation of pulmonary AhR and potentiates HDLI in newborn mice. These observations are consistent with our previous findings, which suggest that AhR activation plays a protective role in HDLI in newborn mice. © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. A study of modelling simplifications in ground vibration predictions for railway traffic at grade

    NASA Astrophysics Data System (ADS)

    Germonpré, M.; Degrande, G.; Lombaert, G.

    2017-10-01

    Accurate computational models are required to predict ground-borne vibration due to railway traffic. Such models generally require a substantial computational effort. Therefore, much research has focused on developing computationally efficient methods, by either exploiting the regularity of the problem geometry in the direction along the track or assuming a simplified track structure. This paper investigates the modelling errors caused by commonly made simplifications of the track geometry. A case study is presented investigating a ballasted track in an excavation. The soil underneath the ballast is stiffened by a lime treatment. First, periodic track models with different cross sections are analyzed, revealing that a prediction of the rail receptance only requires an accurate representation of the soil layering directly underneath the ballast. A much more detailed representation of the cross sectional geometry is required, however, to calculate vibration transfer from track to free field. Second, simplifications in the longitudinal track direction are investigated by comparing 2.5D and periodic track models. This comparison shows that the 2.5D model slightly overestimates the track stiffness, while the transfer functions between track and free field are well predicted. Using a 2.5D model to predict the response during a train passage leads to an overestimation of both train-track interaction forces and free field vibrations. A combined periodic/2.5D approach is therefore proposed in this paper. First, the dynamic axle loads are computed by solving the train-track interaction problem with a periodic model. Next, the vibration transfer to the free field is computed with a 2.5D model. This combined periodic/2.5D approach only introduces small modelling errors compared to an approach in which a periodic model is used in both steps, while significantly reducing the computational cost.

  1. Biotechnological uses of RNAi in plants: risk assessment considerations.

    PubMed

    Casacuberta, Josep M; Devos, Yann; du Jardin, Patrick; Ramon, Matthew; Vaucheret, Hervé; Nogué, Fabien

    2015-03-01

    RNAi offers opportunities to generate new traits in genetically modified (GM) plants. Instead of expressing novel proteins, RNAi-based GM plants reduce target gene expression. Silencing of off-target genes may trigger unintended effects, and identifying these genes would facilitate risk assessment. However, using bioinformatics alone is not reliable, due to the lack of genomic data and insufficient knowledge of mechanisms governing mRNA-small (s)RNA interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Energy Efficiency of Low-Temperature Deaeration of Makeup Water for a District Heating System

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

    Sharapov, V. I., E-mail: vlad-sharapov2008@yandex.ru; Kudryavtseva, E. V.

    2016-07-15

    It is shown that the temperature of makeup water in district heating systems has a strong effect on the energy efficiency of turbines of thermal power plants. A low-temperature deaeration process that considerably improves the energy efficiency of thermal power plants is developed. The desorbing agent is the gas supplied to the burners of the boiler. The energy efficiency of the process for a typical unit of thermal power plant is assessed.

  3. Higher-order time integration of Coulomb collisions in a plasma using Langevin equations

    DOE PAGES

    Dimits, A. M.; Cohen, B. I.; Caflisch, R. E.; ...

    2013-02-08

    The extension of Langevin-equation Monte-Carlo algorithms for Coulomb collisions from the conventional Euler-Maruyama time integration to the next higher order of accuracy, the Milstein scheme, has been developed, implemented, and tested. This extension proceeds via a formulation of the angular scattering directly as stochastic differential equations in the two fixed-frame spherical-coordinate velocity variables. Results from the numerical implementation show the expected improvement [O(Δt) vs. O(Δt 1/2)] in the strong convergence rate both for the speed |v| and angular components of the scattering. An important result is that this improved convergence is achieved for the angular component of the scattering ifmore » and only if the “area-integral” terms in the Milstein scheme are included. The resulting Milstein scheme is of value as a step towards algorithms with both improved accuracy and efficiency. These include both algorithms with improved convergence in the averages (weak convergence) and multi-time-level schemes. The latter have been shown to give a greatly reduced cost for a given overall error level when compared with conventional Monte-Carlo schemes, and their performance is improved considerably when the Milstein algorithm is used for the underlying time advance versus the Euler-Maruyama algorithm. A new method for sampling the area integrals is given which is a simplification of an earlier direct method and which retains high accuracy. Lastly, this method, while being useful in its own right because of its relative simplicity, is also expected to considerably reduce the computational requirements for the direct conditional sampling of the area integrals that is needed for adaptive strong integration.« less

  4. A new look at the multi-G model for organic carbon degradation in surface marine sediments for coupled benthic-pelagic simulations of the global ocean

    NASA Astrophysics Data System (ADS)

    Stolpovsky, Konstantin; Dale, Andrew W.; Wallmann, Klaus

    2018-06-01

    The kinetics of particulate organic carbon (POC) mineralization in marine surface sediments is not well constrained. This creates considerable uncertainties when benthic processes are considered in global biogeochemical or Earth system circulation models to simulate climate-ocean interactions and biogeochemical tracer distributions in the ocean. In an attempt to improve our understanding of the rate and depth distribution of organic carbon mineralization in bioturbated (0-20 cm) sediments at the global scale, we parameterized a 1-D diagenetic model that simulates the mineralization of three discrete POC pools (a multi-G model). The rate constants of the three reactive classes (highly reactive, reactive, refractory) are fixed and determined to be 70, 0.5 and ˜ 0.001 yr-1, respectively, based on the Martin curve model for pelagic POC degradation. In contrast to previous approaches, however, the reactivity of the organic material degraded in the seafloor is continuous with, and set by, the apparent reactivity of material sinking through the water column. Despite the simplifications of describing POC remineralization using G-type approaches, the model is able to simulate a global database (185 stations) of benthic oxygen and nitrate fluxes across the sediment-water interface in addition to porewater oxygen and nitrate distributions and organic carbon burial efficiencies. It is further consistent with degradation experiments using fresh phytoplankton reported in a previous study. We propose that an important yet mostly overlooked consideration in upscaling approaches is the proportion of the reactive POC classes reaching the seafloor in addition to their reactivity. The approach presented is applicable to both steady-state and non-steady state scenarios, and links POC degradation kinetics in sedimentary environments to water depth and the POC rain rate to the seafloor.

  5. Effect of the Internet Commerce on Dispersal Modes of Invasive Alien Species

    PubMed Central

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M. H.; Moroń, Dawid; Sutherland, William J.; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal. PMID:24932498

  6. Introduction of the trapezoidal thermodynamic technique method for measuring and mapping the efficiency of waste-to-energy plants: A potential replacement to the R1 formula.

    PubMed

    Vakalis, Stergios; Moustakas, Konstantinos; Loizidou, Maria

    2018-06-01

    Waste-to-energy plants have the peculiarity of being considered both as energy production and as waste destruction facilities and this distinction is important for legislative reasons. The efficiency of waste-to-energy plants must be objective and consistent, independently if the focus is the production of energy, the destruction of waste or the recovery/upgrade of materials. With the introduction of polygeneration technologies, like gasification, the production of energy and the recovery/upgrade of materials, are interconnected. The existing methodology for assessing the efficiency of waste-to-energy plants is the R1 formula, which does not take into consideration the full spectrum of the operations that take place in waste-to-energy plants. This study introduces a novel methodology for assessing the efficiency of waste-to-energy plants and is defined as the 3T method, which stands for 'trapezoidal thermodynamic technique'. The 3T method is an integrated approach for assessing the efficiency of waste-to-energy plants, which takes into consideration not only the production of energy but also the quality of the products. The value that is returned from the 3T method can be placed in a tertiary diagram and the global efficiency map of waste-to-energy plants can be produced. The application of the 3T method showed that the waste-to-energy plants with high combined heat and power efficiency and high recovery of materials are favoured and these outcomes are in accordance with the cascade principle and with the high cogeneration standards that are set by the EU Energy Efficiency Directive.

  7. Effect of the internet commerce on dispersal modes of invasive alien species.

    PubMed

    Lenda, Magdalena; Skórka, Piotr; Knops, Johannes M H; Moroń, Dawid; Sutherland, William J; Kuszewska, Karolina; Woyciechowski, Michał

    2014-01-01

    The spread of invasive alien plants has considerable environmental and economic consequences, and is one of the most challenging ecological problems. The spread of invasive alien plant species depends largely on long-distance dispersal, which is typically linked with human activity. The increasing domination of the internet will have impacts upon almost all components of our lives, including potential consequences for the spread of invasive species. To determine whether the rise of Internet commerce has any consequences for the spread of invasive alien plant species, we studied the sale of thirteen of some of the most harmful Europe invasive alien plant species sold as decorative plants from twenty-eight large, well known gardening shops in Poland that sold both via the Internet and through traditional customer sales. We also analyzed temporal changes in the number of invasive plants sold in the largest Polish internet auction portal. When sold through the Internet invasive alien plant species were transported considerably longer distances than for traditional sales. For internet sales, seeds of invasive alien plant species were transported further than were live plants saplings; this was not the case for traditional sales. Also, with e-commerce the shape of distance distribution were flattened with low skewness comparing with traditional sale where the distributions were peaked and right-skewed. Thus, e-commerce created novel modes of long-distance dispersal, while traditional sale resembled more natural dispersal modes. Moreover, analysis of sale in the biggest Polish internet auction portal showed that the number of alien specimens sold via the internet has increased markedly over recent years. Therefore internet commerce is likely to increase the rate at which ecological communities become homogenized and increase spread of invasive species by increasing the rate of long distance dispersal.

  8. PLANTS AS BIO-MONITORS FOR 137CS, 238PU, 239, 240PU AND 40K AT THE SAVANNAH RIVER SITE

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

    Caldwell, E.; Duff, M.; Ferguson, C.

    2010-12-16

    The nuclear fuel cycle generates a considerable amount of radioactive waste, which often includes nuclear fission products, such as strontium-90 ({sup 90}Sr) and cesium-137 ({sup 137}Cs), and actinides such as uranium (U) and plutonium (Pu). When released into the environment, large quantities of these radionuclides can present considerable problems to man and biota due to their radioactive nature and, in some cases as with the actinides, their chemical toxicity. Radionuclides are expected to decay at a known rate. Yet, research has shown the rate of elimination from an ecosystem to differ from the decay rate due to physical, chemical andmore » biological processes that remove the contaminant or reduce its biological availability. Knowledge regarding the rate by which a contaminant is eliminated from an ecosystem (ecological half-life) is important for evaluating the duration and potential severity of risk. To better understand a contaminants impact on an environment, consideration should be given to plants. As primary producers, they represent an important mode of contamination transfer from sediments and soils into the food chain. Contaminants that are chemically and/or physically sequestered in a media are less likely to be bio-available to plants and therefore an ecosystem.« less

  9. Development of a CAD Model Simplification Framework for Finite Element Analysis

    DTIC Science & Technology

    2012-01-01

    A. Senthil Kumar , and KH Lee. Automatic solid decomposition and reduction for non-manifold geometric model generation. Computer-Aided Design, 36(13...CAD/CAM: concepts, techniques, and applications. Wiley-interscience, 1995. [38] Avneesh Sud, Mark Foskey, and Dinesh Manocha. Homotopy-preserving

  10. Synthesis and evaluation of phosphortriamidates in wood for thermal and fungal decay protection

    Treesearch

    George C. Chen

    2008-01-01

    The objective of this study was to evaluate the possibility of simplification of the process. The question in focus was simply whether phosphortriamidates impregnated wood would be as effective concerning fire resistance and fungal decay as phosphoramidate bonded wood.

  11. Hydrogen-oxygen proton-exchange membrane fuel cells and electrolyzers

    NASA Technical Reports Server (NTRS)

    Baldwin, R.; Pham, M.; Leonida, A.; Mcelroy, J.; Nalette, T.

    1990-01-01

    A flight experiment is planned for the validation, in a microgravity environment, of several ground-proven simplification features relating to SPE fuel cells and SPE electrolyzers. With a successful experiment, these features can be incorporated into equipment designs for specific extraterrestrial energy storage applications.

  12. Elaboration and Simplification in Spanish Discourse

    ERIC Educational Resources Information Center

    Granena, Gisela

    2008-01-01

    This article compares spoken discourse models in Spanish as a second language textbooks and online language learning resources with naturally occurring conversations. Telephone service encounters are analyzed from the point of view of three different dimensions of authenticity: linguistic, sociolinguistic, and psycholinguistic. An analysis of 20…

  13. 77 FR 48007 - Administrative Simplification: Adoption of Operating Rules for Health Care Electronic Funds...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-10

    ... care transactions results in higher use of EDI by health care providers.\\8\\ We expect usage of EFT and..., surveys, and straw polls, and shared updates on the CAQH CORE and NACHA Web sites. On August 1, 2011 CAQH...

  14. 76 FR 81432 - Revision of Patent Term Adjustment Provisions Relating to Appellate Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ..., interference proceedings, and successful appellate review (the ``C'' provision), with the legislative history..., simplification and harmonization across government agencies and identified goals designed to promote innovation... public; and (9) ensured the objectivity of scientific and technological information and processes. D...

  15. Recruiting Teachers--Future Prospects.

    ERIC Educational Resources Information Center

    Schlechty, Phillip C.; Joslin, Anne W.

    1984-01-01

    Comprehensive reform in the ways teachers are recruited, trained, evaluated, and rewarded is required if the status of the teaching profession and the present quality of education is to be improved. A new career structure, simplification of certification, and reconceptualization of the teaching role are possible remedies. (KH)

  16. Linguistic Aspects of Legal Language.

    ERIC Educational Resources Information Center

    Crandall, JoAnn; Charrow, Veda R.

    Efforts to simplify language used in consumer documents come from the consumer movement and a public disillusioned with big business and government. Even before President Carter's 1978 executive order mandating simplification in government regulations, some agencies were revising regulations for clarity. However, these efforts were based on too…

  17. The Need for a Contemporary Theory of Job Design.

    ERIC Educational Resources Information Center

    Martelli, Joseph T.

    1982-01-01

    Presents a critique of Taylor's scientific management theory and the negative consequences of work simplification. Compares this method with Maslow's, Herzberg's, and Thorsrud's theories of motivation, and contrasts the experiences of General Motors' application of Taylor's model and General Foods' application of Thorsrud's. (SK)

  18. 77 FR 21846 - Reserve Requirements of Depository Institutions: Reserves Simplification

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-12

    ... reserve balance requirements in place of carryover and routine penalty waivers, discontinues as-of..., and eliminates the contractual clearing balance program. The amendments are designed to reduce the... balances maintained at each depository institution are subject to reserve requirement ratios of zero, three...

  19. Paper Abstract Animals

    ERIC Educational Resources Information Center

    Sutley, Jane

    2010-01-01

    Abstraction is, in effect, a simplification and reduction of shapes with an absence of detail designed to comprise the essence of the more naturalistic images being depicted. Without even intending to, young children consistently create interesting, and sometimes beautiful, abstract compositions. A child's creations, moreover, will always seem to…

  20. 24 CFR 570.913 - Other remedies for noncompliance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF... their counsel; (vi) Hold conferences for the settlement or simplification of the issues by consent of... Community Planning and Development files an exception and request for review by the Secretary. The excepting...

  1. 24 CFR 570.496 - Remedies for noncompliance; opportunity for hearing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT... the parties and their counsel; (vi) To hold conferences for the settlement or simplification of the... the decision, either the respondent or the Assistant Secretary for Community Planning and Development...

  2. Zoology: At Last an Exit for Ctenophores.

    PubMed

    Giribet, Gonzalo

    2016-10-24

    Ctenophores, one of the most basal branches in the tree of life, have been found to have a through-gut, complete with mouth and anus. Basal animals are surprisingly complex and simplification has been rampant in animal evolution. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Soil biodiversity and soil community composition determine ecosystem multifunctionality

    PubMed Central

    Wagg, Cameron; Bender, S. Franz; Widmer, Franco; van der Heijden, Marcel G. A.

    2014-01-01

    Biodiversity loss has become a global concern as evidence accumulates that it will negatively affect ecosystem services on which society depends. So far, most studies have focused on the ecological consequences of above-ground biodiversity loss; yet a large part of Earth’s biodiversity is literally hidden below ground. Whether reductions of biodiversity in soil communities below ground have consequences for the overall performance of an ecosystem remains unresolved. It is important to investigate this in view of recent observations that soil biodiversity is declining and that soil communities are changing upon land use intensification. We established soil communities differing in composition and diversity and tested their impact on eight ecosystem functions in model grassland communities. We show that soil biodiversity loss and simplification of soil community composition impair multiple ecosystem functions, including plant diversity, decomposition, nutrient retention, and nutrient cycling. The average response of all measured ecosystem functions (ecosystem multifunctionality) exhibited a strong positive linear relationship to indicators of soil biodiversity, suggesting that soil community composition is a key factor in regulating ecosystem functioning. Our results indicate that changes in soil communities and the loss of soil biodiversity threaten ecosystem multifunctionality and sustainability. PMID:24639507

  4. Significance of breeding in fast nuclear reactors

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

    Raza, S.M.; Abidi, S.B.M.

    1983-12-01

    Only breeder reactors--nuclear power plants that produce more fuel than they consume--are capable in principle of extracting the maximum amount of fission energy contained in uranium ore, thus offering a practical long-term solution to uranium supply problems. Uranium would then constitute a virtually inexhaustible fuel reserve for the world's future energy needs. The ultimate argument for breeding is to conserve the energy resources available to mankind. A long-term role for nuclear power with fast reactors is proven to be economically viable, environmentally acceptable and capable of wide scale exploitation in many countries. In this paper, various suggestions pertaining to themore » fuel fabrication route, fuel cycle economics, studies of the physics of fast nuclear reactors and of engineering design simplifications are presented. Fast reactors contain no moderator and inherently require enriched fuel. In general, the main aim is to suggest an improvement in the understanding of the safety and control characteristics of fast breeder power reactors. Development work is also being devoted to new carbide and nitride fuels, which are likely to exhibit breeding characteristics superior to those of the oxides of plutonium and uranium.« less

  5. Direct Methanol Fuel Cell Power Supply For All-Day True Wireless Mobile Computing

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

    Brian Wells

    PolyFuel has developed state-of-the-art portable fuel cell technology for the portable computing market. A novel approach to passive water recycling within the MEA has led to significant system simplification and size reduction. Miniature stack technology with very high area utilization and minimalist seals has been developed. A highly integrated balance of plant with very low parasitic losses has been constructed around the new stack design. Demonstration prototype systems integrated with laptop computers have been shown in recent months to leading OEM computer manufacturers. PolyFuel intends to provide this technology to its customers as a reference design as a means ofmore » accelerating the commercialization of portable fuel cell technology. The primary goal of the project was to match the energy density of a commercial lithium ion battery for laptop computers. PolyFuel made large strides against this goal and has now demonstrated 270 Wh/liter compared with lithium ion energy densities of 300 Wh/liter. Further, more incremental, improvements in energy density are envisioned with an additional 20-30% gains possible in each of the next two years given further research and development.« less

  6. Performance of fuzzy approach in Malaysia short-term electricity load forecasting

    NASA Astrophysics Data System (ADS)

    Mansor, Rosnalini; Zulkifli, Malina; Yusof, Muhammad Mat; Ismail, Mohd Isfahani; Ismail, Suzilah; Yin, Yip Chee

    2014-12-01

    Many activities such as economic, education and manafucturing would paralyse with limited supply of electricity but surplus contribute to high operating cost. Therefore electricity load forecasting is important in order to avoid shortage or excess. Previous finding showed festive celebration has effect on short-term electricity load forecasting. Being a multi culture country Malaysia has many major festive celebrations such as Eidul Fitri, Chinese New Year and Deepavali but they are moving holidays due to non-fixed dates on the Gregorian calendar. This study emphasis on the performance of fuzzy approach in forecasting electricity load when considering the presence of moving holidays. Autoregressive Distributed Lag model was estimated using simulated data by including model simplification concept (manual or automatic), day types (weekdays or weekend), public holidays and lags of electricity load. The result indicated that day types, public holidays and several lags of electricity load were significant in the model. Overall, model simplification improves fuzzy performance due to less variables and rules.

  7. Applications of Sentinel-2 data for agriculture and forest monitoring using the absolute difference (ZABUD) index derived from the AgroEye software (ESA)

    NASA Astrophysics Data System (ADS)

    de Kok, R.; WeŻyk, P.; PapieŻ, M.; Migo, L.

    2017-10-01

    To convince new users of the advantages of the Sentinel_2 sensor, a simplification of classic remote sensing tools allows to create a platform of communication among domain specialists of agricultural analysis, visual image interpreters and remote sensing programmers. An index value, known in the remote sensing user domain as "Zabud" was selected to represent, in color, the essentials of a time series analysis. The color index used in a color atlas offers a working platform for an agricultural field control. This creates a database of test and training areas that enables rapid anomaly detection in the agricultural domain. The use cases and simplifications now function as an introduction to Sentinel_2 based remote sensing, in an area that before relies on VHR imagery and aerial data, to serve mainly the visual interpretation. The database extension with detected anomalies allows developers of open source software to design solutions for further agricultural control with remote sensing.

  8. A simplification of the fractional Hartley transform applied to image security system in phase

    NASA Astrophysics Data System (ADS)

    Jimenez, Carlos J.; Vilardy, Juan M.; Perez, Ronal

    2017-01-01

    In this work we develop a new encryption system for encoded image in phase using the fractional Hartley transform (FrHT), truncation operations and random phase masks (RPMs). We introduce a simplification of the FrHT with the purpose of computing this transform in an efficient and fast way. The security of the encryption system is increased by using nonlinear operations, such as the phase encoding and the truncation operations. The image to encrypt (original image) is encoded in phase and the truncation operations applied in the encryption-decryption system are the amplitude and phase truncations. The encrypted image is protected by six keys, which are the two fractional orders of the FrHTs, the two RPMs and the two pseudorandom code images generated by the amplitude and phase truncation operations. All these keys have to be correct for a proper recovery of the original image in the decryption system. We present digital results that confirm our approach.

  9. Determining tumor blood flow parameters from dynamic image measurements

    NASA Astrophysics Data System (ADS)

    Libertini, Jessica M.

    2008-11-01

    Many recent cancer treatments focus on preventing angiogenesis, the process by which a tumor promotes the growth of large and efficient capillary beds for the increased nourishment required to support the tumor's rapid growth[l]. To measure the efficacy of these treatments in a timely fashion, there is an interest in using data from dynamic sequences of contrast-enhanced medical imaging, such as MRI and CT, to measure blood flow parameters such as perfusion, permeability-surface-area product, and the relative volumes of the plasma and extracellular-extravascular space. Starting with a two compartment model presented by the radiology community[2], this work challenges the application of a simplification to this problem, which was originally developed to model capillary reuptake[3]. While the primary result of this work is the demonstration of the inaccuracy of this simplification, the remainder of the paper is dedicated to presenting alternative methods for calculating the perfusion and plasma volume coefficients. These methods are applied to model data sets based on real patient data, and preliminary results are presented.

  10. The dynamic genome of Hydra.

    PubMed

    Chapman, Jarrod A; Kirkness, Ewen F; Simakov, Oleg; Hampson, Steven E; Mitros, Therese; Weinmaier, Thomas; Rattei, Thomas; Balasubramanian, Prakash G; Borman, Jon; Busam, Dana; Disbennett, Kathryn; Pfannkoch, Cynthia; Sumin, Nadezhda; Sutton, Granger G; Viswanathan, Lakshmi Devi; Walenz, Brian; Goodstein, David M; Hellsten, Uffe; Kawashima, Takeshi; Prochnik, Simon E; Putnam, Nicholas H; Shu, Shengquiang; Blumberg, Bruce; Dana, Catherine E; Gee, Lydia; Kibler, Dennis F; Law, Lee; Lindgens, Dirk; Martinez, Daniel E; Peng, Jisong; Wigge, Philip A; Bertulat, Bianca; Guder, Corina; Nakamura, Yukio; Ozbek, Suat; Watanabe, Hiroshi; Khalturin, Konstantin; Hemmrich, Georg; Franke, André; Augustin, René; Fraune, Sebastian; Hayakawa, Eisuke; Hayakawa, Shiho; Hirose, Mamiko; Hwang, Jung Shan; Ikeo, Kazuho; Nishimiya-Fujisawa, Chiemi; Ogura, Atshushi; Takahashi, Toshio; Steinmetz, Patrick R H; Zhang, Xiaoming; Aufschnaiter, Roland; Eder, Marie-Kristin; Gorny, Anne-Kathrin; Salvenmoser, Willi; Heimberg, Alysha M; Wheeler, Benjamin M; Peterson, Kevin J; Böttger, Angelika; Tischler, Patrick; Wolf, Alexander; Gojobori, Takashi; Remington, Karin A; Strausberg, Robert L; Venter, J Craig; Technau, Ulrich; Hobmayer, Bert; Bosch, Thomas C G; Holstein, Thomas W; Fujisawa, Toshitaka; Bode, Hans R; David, Charles N; Rokhsar, Daniel S; Steele, Robert E

    2010-03-25

    The freshwater cnidarian Hydra was first described in 1702 and has been the object of study for 300 years. Experimental studies of Hydra between 1736 and 1744 culminated in the discovery of asexual reproduction of an animal by budding, the first description of regeneration in an animal, and successful transplantation of tissue between animals. Today, Hydra is an important model for studies of axial patterning, stem cell biology and regeneration. Here we report the genome of Hydra magnipapillata and compare it to the genomes of the anthozoan Nematostella vectensis and other animals. The Hydra genome has been shaped by bursts of transposable element expansion, horizontal gene transfer, trans-splicing, and simplification of gene structure and gene content that parallel simplification of the Hydra life cycle. We also report the sequence of the genome of a novel bacterium stably associated with H. magnipapillata. Comparisons of the Hydra genome to the genomes of other animals shed light on the evolution of epithelia, contractile tissues, developmentally regulated transcription factors, the Spemann-Mangold organizer, pluripotency genes and the neuromuscular junction.

  11. The costs and benefits of a cigarette ban.

    PubMed

    Doucet, Mathieu

    2017-06-01

    The death toll from tobacco is staggering: it might contribute to one billion premature deaths over the course of the 21st century. In 'The case for banning cigarettes', Kalle Grill and Kristin Voigt argue that the well-being and equality benefits of a complete ban on cigarettes more than justify the restrictions on autonomy that such a ban would impose. Their argument depends on two crucial simplifications: an assumption that the ban would be effective and the restriction of the analysis to a comparison with the status quo, rather than a broader range of policy options. I argue that despite the authors' claims, these two simplifications make it impossible for their argument to 'bring into focus the fundamental normative issues' surrounding a possible cigarette ban, since they dramatically overstate the benefits and obscure the most significant costs of such a ban. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  12. The Role of Surface, Semantic and Grammatical Features on Simplification of Spanish Medical Texts: A User Study

    PubMed Central

    Mukherjee, Partha; Leroy, Gondy; Kauchak, David; Navarrete, Brianda Armenta; Diaz, Damian Y.; Colina, Sonia

    2017-01-01

    Simplifying medical texts facilitates readability and comprehension. While most simplification work focuses on English, we investigate whether features important for simplifying English text are similarly helpful for simplifying Spanish text. We conducted a user study on 15 Spanish medical texts using Amazon Mechanical Turk and measured perceived and actual difficulty. Using the median of the difficulty scores, we split the texts into easy and difficult groups and extracted 10 surface, 2 semantic and 4 grammatical features. Using t-tests, we identified those features that significantly distinguish easy text from difficult text in Spanish and compare with prior work in English. We found that easy Spanish texts use more repeated words and adverbs, less negations and more familiar words, similar to English. Also like English, difficult Spanish texts use more nouns and adjectives. However in contrast to English, easier Spanish texts contained longer sentences and used grammatical structures that were more varied. PMID:29854201

  13. Injury to plants from rapidly dropping temperature in Washington and northern Idaho

    Treesearch

    R. Daubenmire

    1957-01-01

    In nearly 70 years of recorded weather history, Washington and northern Idaho have on three occasions experienced exceptionally sharp freezes in late autumn or early winter that caused considerable damage to plants. A brief review of these events is warranted since the records are consistent enough to permit the drawing of significant conclusions.

  14. 76 FR 34746 - Species Proposals for Consideration at the Sixteenth Regular Meeting of the Conference of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... recommendations on animal and plant species that should be considered as candidates for U.S. proposals to amend... to regulate international trade in certain animal and plant species that are now, or potentially may become, threatened with extinction. These species are listed in the Appendices to CITES, which are...

  15. Extracting plant phenology metrics in a Great Basin watershed: methods and considerations for quantifying phenophases in a cold desert

    USDA-ARS?s Scientific Manuscript database

    Plant phenology is recognized as important for all trophic interactions. There has been a recent advent of phenology and camera networks worldwide. The established PhenoCam Network has sites in coterminous United States, including the western states. However, there is a paucity of published research...

  16. Public Understanding of Plant Biology: Voices from the Bottom of the Garden

    ERIC Educational Resources Information Center

    Watts, Mike

    2015-01-01

    Many household gardeners accumulate considerable knowledge of plant biology through a range of informal learning sources. This knowledge seldom relates to school biology and is driven by interest, keen motivation and what is termed here "vital relevance." A small opportunity sample of 12 gardeners (6 M, 6 F) is interviewed in terms of…

  17. Advances and considerations in technologies for growing, imaging, and analyzing 3-D root system architecture

    USDA-ARS?s Scientific Manuscript database

    The ability of a plant to mine the soil for nutrients and water is determined by how, where, and when roots are arranged in the soil matrix. The capacity of plant to maintain or improve its yield under limiting conditions, such as nutrient deficiency or drought, is affected by root system architectu...

  18. 76 FR 52356 - Indiana Michigan Power Company, Donald C. Cook Nuclear Plant, Unit 1; Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-22

    ... adversely affect plant safety, and would have no adverse effect on the probability of any accident. For the accidents that involve damage or melting of the fuel in the reactor core, fuel rod integrity has been shown to be unaffected by extended burnup under consideration; therefore, the probability of an accident...

  19. 77 FR 51071 - Indiana Michigan Power Company, Donald C. Cook Nuclear Plant, Unit 2, Environmental Assessment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... adversely affect plant safety, and would have no adverse effect on the probability of any accident. For the accidents that involve damage or melting of the fuel in the reactor core, fuel rod integrity has been shown to be unaffected by extended burnup under consideration; therefore, the consequences of an accident...

  20. METRO-APEX Volume 12.1: Industrialist's Manual No. 2, People's Pulp Plant. Revised.

    ERIC Educational Resources Information Center

    University of Southern California, Los Angeles. COMEX Research Project.

    The Industrialist's Manual No. 2 (People's Pulp Plant) is one of a set of twenty-one manuals used in METRO-APEX 1974, a computerized college and professional level, computer-supported, role-play, simulation exercise of a community with "normal" problems. Stress is placed on environmental quality considerations. APEX 1974 is an expansion…

Top